Placing ultra-small or ultra-thin discrete components

Abstract

To provide methods for setting up ultra-small or ultra-thin discrete components for easy pick and place in integrated circuit packaging.SOLUTION: A method includes: dicing a wafer to form discrete components; transferring the discrete components onto a transparent carrier, including bonding the discrete component to a carrier release layer on the transparent carrier; and releasing one of the discrete components from the transparent carrier, the one of the discrete components being deposited on a device substrate after the releasing.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] This application claims priority to U.S. Patent Application No. 62 / 279,143, filed Jan. 15, 2016, the entire contents of which are incorporated herein by reference.

[0002] The description herein relates generally to the arrangement of ultra-small or ultra-thin discrete components. [Background technology]

[0003] Known assembly processes automate the transfer of items from one location to another using robotic pick-and-place systems, fluidic self-assembly systems, light-assisted assembly systems, or other systems. Summary of the Invention [Problem to be solved by the invention]

[0004] Methods for locating ultra-small or ultra-thin discrete components for easy pick-and-place in integrated circuit packaging are believed to be disclosed in U.S. Patent Application No. 62 / 033,595, filed August 5, 2014, and PCT Application No. PCT / US2015 / 043550, filed August 4, 2015, the contents of both of which are incorporated herein by reference in their entireties. [Means for solving the problem]

[0005] In one aspect, the method includes dicing the wafer to form discrete components; transferring the discrete components onto a transparent carrier, including adhering the discrete components to a carrier release layer on the transparent carrier; and releasing one of the discrete components from the transparent carrier, where one of the discrete components is deposited on a device substrate after release.

[0006] Implementations may include one or more of the following features.

[0007] The method includes thinning the wafer to a thickness of less than 50 μm. Dicing the wafer includes dicing the thinned wafer to form discrete components.

[0008] Dicing the wafer includes adhering the wafer to a dicing carrier. Transferring the discrete components onto the transparent carrier includes transferring the discrete components from the dicing carrier to the transparent carrier. The dicing carrier includes a dicing tape.

[0009] Releasing one of the discrete components from the transparent carrier includes applying a stimulus to a carrier release layer on the transparent carrier, the stimulus including ultraviolet (UV) light.

[0010] The transparent carrier is at least partially transparent to UV light.

[0011] The carrier releasing layer includes a dynamic releasing layer (DRL).

[0012] The step of depositing one of the discrete components on the device substrate includes depositing one of the discrete components on an attachment element disposed on a surface of the device substrate. The attachment element includes a thermally curable material. The attachment element includes a UV curable material. The attachment element includes a conductive material. The method includes applying a stimulus to cure the attachment element. Applying the stimulus to cure the attachment element electrically connects the discrete component to the device substrate.

[0013] The method includes bonding the discrete components to a device substrate.

[0014] The method includes attaching the wafer to a handle substrate to form a wafer handle assembly. Attaching the wafer to the handle substrate includes attaching the wafer to a handle release layer formed on a surface of the handle substrate. The handle release layer includes a heat sensitive material. The handle release layer includes an ultraviolet (UV) sensitive material. Dicing the wafer into discrete components includes dicing the wafer handle assembly into handle assemblies, each handle assembly including a discrete component attached to a corresponding portion of the handle substrate. Transferring the discrete components onto a transparent carrier includes transferring the handle assembly onto a transparent carrier. Depositing one of the discrete components onto the device substrate includes depositing one of the handle assemblies onto the transparent carrier. The method includes releasing the corresponding portion of the handle substrate from the discrete components deposited on the device substrate. The method includes simultaneously releasing the corresponding portion of the handle substrate from the discrete components deposited on the device substrate and bonding the discrete components to the device substrate. The method includes applying a stimulus that causes (i) bonding of the discrete components to the device substrate and (ii) release of the handle substrate from the discrete components. The method includes applying a first stimulus that causes bonding of the discrete components to the device substrate and a second stimulus that causes release of the handle substrate from the discrete components. The method includes thinning a wafer to a thickness of less than 50 μm. The method includes attaching the thinned wafer to the handle substrate to form a wafer-handle assembly.

[0015] Each discrete component is ultra-thin, ultra-miniature, or both ultra-thin and ultra-miniature. Each discrete component has a thickness of 50 μm or less. Each discrete component has a maximum length of 300 μm / side or less.

[0016] In one aspect, the method includes releasing a handle assembly from a transparent carrier, which after release is deposited on a device substrate, the handle assembly including discrete components releasably attached to the handle substrate, the discrete components being ultra-thin, ultra-miniature, or both ultra-thin and ultra-miniature.

[0017] Implementations may include one or more of the following features.

[0018] The handle substrate has a thickness of at least 50 μm.

[0019] The method includes attaching a handle assembly to a transparent carrier. Attaching the handle assembly to the transparent carrier includes transferring the handle assembly from a dicing carrier to the transparent carrier.

[0020] The method includes attaching a wafer to a handle substrate to form a wafer handle assembly, the discrete components being formed on the wafer. Attaching the wafer to the handle substrate includes attaching the wafer to a handle release layer formed on a surface of the handle substrate. The handle release layer includes a heat sensitive material. The handle release layer includes a UV sensitive material. The method includes dicing the wafer handle assembly to form a handle assembly. The method includes attaching the handle assembly to a transparent carrier. The method includes thinning the wafer to a thickness of less than 50 μm. The method includes attaching the thinned wafer to a handle substrate to form a wafer handle substrate. The method includes attaching the wafer handle assembly to a transparent carrier. The method includes dicing the wafer handle assembly attached to the transparent carrier into a handle assembly. The method includes partially dicing the wafer handle assembly, the dicing including dicing less than a full thickness of the wafer handle assembly. Attaching the wafer handle assembly to the transparent carrier includes attaching the partially diced wafer handle assembly to the transparent carrier. The method includes dicing a partially diced wafer-handle assembly attached to a transparent carrier into a handle assembly. The method includes thinning the wafer to a thickness of less than 50 μm. The method includes attaching the thinned wafer to a handle substrate to form a wafer-handle assembly. The method includes thinning the attached wafer to a thickness of less than 50 μm.

[0021] The transparent carrier is at least partially transparent to ultraviolet light. The transparent carrier comprises glass.

[0022] Releasing the handle assembly from the transparent carrier includes applying a stimulus to a dynamic release layer disposed between the carrier substrate and the handle assembly, the stimulus comprising ultraviolet light. Applying the stimulus to the dynamic release layer causes the dynamic release layer to mechanically release the handle assembly from the transparent carrier.

[0023] Depositing the handle assembly on the device substrate includes depositing the handle assembly on a mounting element disposed on the device substrate. The mounting element includes a thermally curable material. The mounting element includes a UV curable material. The mounting element includes a conductive material. The method includes applying a stimulus to cure the mounting element.

[0024] The method includes bonding the discrete components to the device substrate. The method includes releasing the handle substrate from the discrete components after depositing the handle assembly on the device substrate. Releasing the handle substrate from the discrete components includes applying a stimulus to release a handle release layer disposed between the handle substrate and the discrete components. The method includes simultaneously bonding the wafer handle assembly to the device substrate and releasing the handle substrate from the discrete components. The method includes applying a stimulus that causes (i) bonding of the discrete components to the device substrate and (ii) release of the handle substrate from the discrete components. The method includes applying a first stimulus that causes bonding of the discrete components to the device substrate and a second stimulus that causes release of the handle substrate from the discrete components.

[0025] In one aspect, the device includes a handle assembly attached to a transparent carrier, the handle assembly including discrete components releasably attached to a handle substrate, the discrete components being ultra-thin, ultra-miniature, or both ultra-thin and ultra-miniature.

[0026] Implementations may include one or more of the following features.

[0027] The apparatus includes a plurality of handle assemblies attached to a transparent carrier.

[0028] The handle substrate has a thickness of at least 50 μm.

[0029] The transparent carrier is at least partially transparent to ultraviolet light.

[0030] The transparent carrier includes glass.

[0031] The transparent carrier includes a dynamic release layer disposed on a surface of the transparent carrier, the dynamic release layer being disposed between the transparent carrier and the handle assembly. The dynamic release layer is disposed between the transparent carrier and the handle assembly. The dynamic release layer is mechanically responsive to an applied stimulus. The applied stimulus includes ultraviolet light.

[0032] The handle substrate includes a handle release layer formed on a surface of the handle substrate, the handle release layer being disposed between the handle substrate and the discrete components. The handle release layer includes a heat sensitive material. The handle release layer includes a UV sensitive material.

[0033] Discrete components include integrated circuits formed on a semiconductor substrate.

[0034] In one aspect, the apparatus includes a wafer-handle assembly mounted on a transparent carrier, the wafer including a wafer releasably attached to a handle substrate, the discrete components being formed on the wafer, and configured such that (i) the discrete components formed on the wafer are ultra-miniature, or (ii) the wafer is ultra-thin, or (iii) both (i) and (ii).

[0035] Implementations may include one or more of the following features.

[0036] The handle substrate has a thickness of at least 50 μm.

[0037] The transparent carrier is at least partially transparent to ultraviolet light.

[0038] The transparent carrier includes glass.

[0039] The transparent carrier includes a dynamic release layer disposed on a surface of the transparent carrier, the dynamic release layer being disposed between the transparent carrier and the wafer handle assembly. The dynamic release layer is disposed between the transparent carrier and the wafer handle assembly. The dynamic release layer is mechanically responsive to an applied stimulus. The applied stimulus includes ultraviolet light.

[0040] The handle substrate includes a handle release layer formed on a surface of the handle substrate, the handle release layer being disposed between the handle substrate and the discrete components. The handle release layer includes a heat sensitive material. The handle release layer includes a UV sensitive material.

[0041] The wafer includes a semiconductor wafer.

[0042] In one aspect, the method includes embedding an assembly including discrete components in a flowable material, the assembly including discrete components being attached to a first handle substrate, and thinning the embedded discrete components to a thickness of less than 50 μm.

[0043] Implementations may include one or more of the following features.

[0044] The assembly including the discrete components includes a handle assembly.

[0045] Embedding the assembly in a flowable material includes depositing a layer of flowable material on a surface of the first handle substrate.

[0046] Embedding the assembly in the flowable material includes disposing a second handle substrate on a surface of a first handle substrate, the assembly being disposed on the surface of the first handle substrate and a layer of flowable material being disposed on the surface of the second handle substrate. Disposing the second handle substrate on the surface of the first handle substrate includes contacting the layer of flowable material disposed on the surface of the second handle substrate with the surface of the first handle substrate. Embedding the assembly in the flowable material includes flowing the layer of flowable material. Flowing the layer of flowable material includes exposing the layer of flowable material to ultraviolet (UV) light. Flowing the layer of flowable material includes exposing the layer of flowable material to a thermal stimulus. The second handle substrate is at least partially transparent to UV light. The second handle substrate includes glass. The method includes removing the second handle substrate.

[0047] The flowable material includes a photoresist.

[0048] The method includes removing the flowable material after thinning the embedded discrete components. The first handle substrate includes a transparent carrier. The method includes transferring the thinned discrete components from the transparent carrier to a device substrate.

[0049] The method includes transferring the thinned discrete components to a third handle substrate. The step of transferring the thinned discrete components to the third handle substrate includes attaching the thinned discrete components to a handle release layer disposed on a surface of the third handle substrate. The step of transferring the thinned discrete components to the third handle substrate includes releasing a handle release layer disposed between the discrete components and the first handle substrate. The step of releasing the handle release layer includes applying a stimulus to the release layer. The stimulus includes UV light. The stimulus includes a thermal stimulus. The method includes dicing the third handle substrate to form a handle assembly including the thinned discrete components attached to corresponding portions of the third handle substrate. The step of dicing the third handle substrate includes dicing the third handle substrate and a handle release layer disposed on a surface of the third handle substrate, the formed handle assembly including the thinned discrete components attached to the handle release layer disposed on the corresponding portions of the third handle substrate. The method includes transferring the handle assembly to a device substrate. The method includes transferring the handle assembly to a device substrate using a pick-and-place approach. The method includes transferring the handle assembly to a transparent carrier. Transferring the handle assembly to the transparent carrier includes adhering the handle assembly to a carrier release layer disposed on the transparent carrier. The method includes transferring the handle assembly from the transparent carrier to the device substrate.

[0050] The method includes attaching a discrete component to a first handle substrate.

[0051] The method includes attaching the discrete components to a handle release layer disposed on a surface of a first handle substrate. The method includes attaching the discrete components to the first handle substrate using a pick-and-place approach. The method includes attaching a plurality of discrete components to the first handle substrate. At least one of the plurality of discrete components is different from each of the others of the plurality of discrete components.

[0052] In one aspect, a method includes exposing a first substrate to a first stimulus, where adhesion between the first substrate and a discrete component bonded to the first substrate decreases in response to the first stimulus; transferring the discrete component from the first substrate to a second substrate; and exposing the second substrate to a second stimulus, where adhesion between the first substrate and the discrete component decreases in response to the second stimulus.

[0053] Implementations may include one or more of the following features.

[0054] The method includes attaching a wafer to a first substrate, the discrete components being formed on the wafer. The method includes dicing the wafer attached to the first substrate to form the discrete components. The attaching the wafer to the first substrate includes attaching a wafer handle assembly to the first substrate, the wafer handle assembly including a wafer attached to a handle substrate. The method includes dicing the wafer handle assembly attached to the first substrate to form handle assemblies, each handle assembly including a discrete component and a corresponding portion of the handle substrate.

[0055] The first substrate includes a dicing tape.

[0056] The step of exposing the first substrate to a first stimulus includes exposing the first substrate to ultraviolet light. The step of exposing the first substrate to a first stimulus includes exposing the first substrate to heat. The step of exposing the second substrate to a second stimulus includes exposing the second substrate to ultraviolet light. The step of exposing the second substrate to a second stimulus includes exposing the second substrate to heat.

[0057] The method includes transferring the discrete components from the second substrate to a transparent carrier.

[0058] The second substrate includes a tape disposed on a vacuum chuck. The method includes applying a vacuum to the vacuum chuck, the applied vacuum securing the tape to the vacuum chuck.

[0059] In one aspect, a method includes dicing a wafer attached to a release layer disposed on a transparent carrier to form discrete components, and exposing the release layer to a stimulus, where adhesion between the release layer and the discrete components decreases in response to the stimulus.

[0060] Implementations may include one or more of the following features.

[0061] Exposing the release layer to the stimulus can include exposing the release layer to heat Exposing the release layer to the stimulus can include exposing the release layer to ultraviolet light.

[0062] The adhesion between the release layer and the discrete components after exposure to the stimulus is sufficient for the discrete components to adhere to the release layer.

[0063] The release layer includes an adhesive layer and a dynamic release layer. When exposed to the stimulus, the adhesive layer reduces its adhesive strength. The method includes exposing the release layer to a second stimulus, where the dynamic release layer is mechanically responsive to the second stimulus. One or more of the discrete components are transferred to the device substrate when the release layer is exposed to the second stimulus.

[0064] The step of dicing the wafer includes dicing the wafer handle assemblies to form handle assemblies, the wafer handle assemblies including a wafer attached to a handle substrate, each handle assembly including one of the discrete components and a corresponding portion of the handle substrate.

[0065] In one aspect, the method includes releasing the discrete components from a release layer on an interim handle by reducing adhesion between the release layer and the discrete components, the reducing including applying a stimulus that causes a change in the surface morphology of the release layer.

[0066] Implementations may include one or more of the following features.

[0067] Altering the surface morphology of the release layer includes blistering the surface. The stimulus includes heat or light.

[0068] In one aspect, the method includes a step of releasing the discrete components from a release layer on the temporary handle by reducing adhesion between the release layer and the discrete components, the reduction including applying a stimulus that causes a phase transition of at least a portion of the release layer.

[0069] Implementations may include one or more of the following features.

[0070] The phase transition may include a solid to liquid transition or a solid to gas transition or both. The stimulus may include heat or pressure or both.

[0071] In one aspect, the method includes a step of releasing the discrete components from a release layer on the temporary handle by reducing adhesion between the release layer and the discrete components, the reduction including applying a stimulus that changes a chemical structure or chemical composition or both of at least a portion of the release layer.

[0072] Implementations may include one or more of the following features.

[0073] A portion of the release layer undergoes thermal decomposition, and a portion of the release layer undergoes photodegradation.

[0074] In one aspect, the method includes a step of releasing a discrete component from a release layer on a temporary handle by reducing adhesion between the release layer and the discrete component, wherein recovery of adhesion after the adhesion is reduced is prevented, inhibited or delayed.

[0075] In one aspect, the method includes a step of releasing the discrete components from the release layer on the temporary handle by reducing adhesion between the release layer and the discrete components, the step including releasing the discrete components without leaving any residue from the release layer on the discrete components after release.

[0076] In one aspect, the method includes releasing the discrete components from a release layer of a temporary handle and depositing the discrete components and a handle substrate, the release layer having a thickness of less than 10 μm prior to release.

[0077] Implementations may include one or more of the following features.

[0078] The release layer comprises a single layer.

[0079] The release layer includes a first layer and a second layer. The release layer includes a first layer attached to the handle and a second layer intended for deposition of discrete components. The second layer is parallel to the first layer. The second layer is UV sensitive. The second layer is heat sensitive. The first layer is a permanent adhesive. The heat sensitivity of the second layer reduces adhesive strength in response to application of thermal energy. The heat sensitivity of the second layer increases adhesive strength in response to application of thermal energy. The UV photosensitivity increases adhesive strength in response to exposure to UV light. The UV photosensitivity reduces adhesive strength in response to exposure to UV light.

[0080] The method includes transferring the discrete components onto a handle substrate for contacting the device substrate. The method includes releasing the discrete components from the handle substrate for depositing the discrete components onto the device substrate. The depositing the discrete components onto the device substrate includes bonding the discrete components to the device substrate. The releasing the discrete components from the handle is performed simultaneously with the bonding the discrete components to the device substrate. The releasing the discrete components from the handle is in response to the bonding the discrete components to the device substrate. The releasing the discrete components from the handle is caused by bonding the discrete components to the device substrate. The releasing the discrete components from the handle is completed after the bonding the discrete components to the device substrate. The discrete components are released from the handle by bonding with the device substrate. The bonding further includes providing thermal energy or UV light for both bonding the discrete components to the substrate and releasing the discrete components from the handle. The handle substrate remains in contact with the device substrate upon releasing the discrete components from the handle substrate. The method includes removing the handle substrate from the discrete components. Removing the handle substrate includes applying at least one of the following, or any combination of two or more thereof: a brush, a blade, compressed air, a vacuum force, vibration, or gravity.

[0081] The handle substrate comprises a thickness between 49 and 801 microns. The handle substrate comprises a thickness between 100 and 800 microns. The handle substrate comprises a thickness between 300 and 800 microns. At least one side of the handle substrate comprises a length between 400 and 600 microns.

[0082] In one aspect, the device includes discrete components attached to the temporary handle via a release layer, the release layer configured to undergo a change in surface morphology in response to an applied stimulus.

[0083] Implementations may include one or more of the following features.

[0084] The variations in surface morphology include blisters.The variations in surface morphology include a plurality of blisters across the surface of the release layer.

[0085] In one aspect, the device includes a discrete component attached to the temporary handle via a release layer, at least a portion of the release layer configured to undergo a phase transition in response to an applied stimulus.

[0086] Implementations may include one or more of the following features.

[0087] A phase transition may include a solid to liquid transition or a solid to gas transition or both.

[0088] In one aspect, the device includes a discrete component attached to the temporary handle via a release layer, at least a portion of the release layer configured to undergo a change in chemical structure or chemical composition, or both, in response to an applied stimulus.

[0089] Implementations may include one or more of the following features.

[0090] The transformation includes thermal decomposition. The transformation includes photolysis.

[0091] In one aspect, the device includes a discrete component attached to the temporary handle via a release layer, the release layer configured to prevent, inhibit or delay recovery of the adhesive strength of the release layer following a decrease in adhesive strength between the release layer and the discrete component.

[0092] In one embodiment, the device comprises discrete components attached to a temporary handle via a release layer, the release layer having a thickness of less than 10 μm.

[0093] In general, in one aspect, a method includes releasing discrete components from a carrier and depositing the discrete components onto a handle substrate, where the discrete components have an ultra-thin, ultra-small, or ultra-thin and ultra-small feature size, and the handle substrate has a thickness of at least 50 microns and at least one side length of at least 300 microns.

[0094] The embodiment may include one or any combination of two or more of the following features. The method may also include a release layer on the handle substrate such that the discrete components are releasably attached to the release layer. The release layer is a heat sensitive material. The release layer is an ultraviolet ("UV") light sensitive material. The release layer includes a first layer and a second layer. The first layer is attached to the handle and the second layer is intended for deposition of the discrete components. The second layer is parallel to the first layer. The second layer is UV sensitive. The second layer is heat sensitive. The first layer is a permanent adhesive. The heat sensitivity of the second layer reduces adhesive strength in response to application of thermal energy. The heat sensitivity of the second layer increases adhesive strength in response to application of thermal energy. The UV light sensitivity increases adhesive strength in response to application of UV light or decreases adhesive strength in response to application of UV light. The method includes transferring the discrete components onto the handle substrate for contact with the device substrate. The method includes releasing the discrete components from the handle substrate for depositing the discrete components on the device substrate. The step of depositing the discrete components on the device substrate includes bonding the discrete components to the device substrate. The step of releasing the discrete components from the handle is performed simultaneously with the step of bonding the discrete components to the device substrate. The step of releasing the discrete components from the handle is in response to the step of bonding the discrete components to the device substrate. The step of releasing the discrete components from the handle is caused by bonding the discrete components to the device substrate. The step of releasing the discrete components from the handle is completed after the step of bonding the discrete components to the device substrate. The discrete components are released from the handle by bonding with the device substrate. The step of bonding further includes providing thermal energy or UV light energy for both bonding the discrete components to the substrate and releasing the discrete components from the handle. The handle substrate remains in contact with the device substrate when releasing the handle substrate from the discrete components. The method further includes removing the handle substrate from the discrete component.Removing the handle substrate may include applying at least one of the following, or any combination of two or more of the following: a brush, a blade, compressed air, a vacuum force, vibration, or gravity. The handle substrate comprises a thickness between 49-801 microns, 100-800 microns, and / or 300-800 microns. At least one side of the handle substrate comprises a length between 400-600 microns.

[0095] In general, in one aspect, a device includes a discrete component having an ultra-thin, ultra-miniature, or ultra-thin and ultra-miniature feature, and a handle substrate releasably attached to the discrete component, where the handle and the discrete component have a feature that is thicker and wider than the discrete component.

[0096] Embodiments may include one or any combination of two or more of the following features. The apparatus also includes a release layer attached to the handle substrate such that the discrete components are releasably attached to the release layer. The release layer is a heat sensitive material. The release layer is a UV sensitive material. The release layer includes a first layer and a second layer. The release layer includes a first layer attached to the handle and a second layer intended for deposition of the discrete components. The second layer is parallel to the first layer. The second layer is UV sensitive. The second layer is heat sensitive. The first layer is a sensitive permanent adhesive. The heat sensitivity of the second layer reduces adhesive strength in response to heat exceeding a thermal parameter of the adhesive. The heat sensitivity of the second layer increases adhesive strength in response to heat exceeding a thermal parameter of the adhesive. The UV sensitivity increases adhesive strength in response to exposure to UV light. The UV sensitivity reduces adhesive strength in response to exposure to UV light. The handle substrate includes a thickness between 49 and 801 microns. At least one side of the handle substrate comprises a length between 100 and 800 microns. At least one side of the handle substrate comprises a length between 300 and 800 microns. At least one side of the handle substrate comprises a length between 400 and 600 microns.

[0097] In general, in one aspect, the method includes applying a processing step that changes a material between a surface of an ultra-thin, micro-miniature or ultra-thin and micro-miniature discrete component and a substrate to which the ultra-thin and micro-miniature discrete component is attached to a state in which the material holds the ultra-thin and micro-miniature discrete component on the substrate. The processing step simultaneously changes a material that temporarily holds an opposing side of the ultra-thin and micro-miniature discrete component on a handle held by a chuck of a pick and place tool to a state in which the material no longer holds the ultra-thin and micro-miniature discrete component on the handle. The method includes a step of inducing a change of state, which includes providing thermal energy, UV light, or both. The material that temporarily holds the opposing side of the discrete component on the handle substrate includes a release layer that includes a first layer and a second layer. The material that temporarily holds the opposing side of the discrete component on the handle substrate includes a release layer that includes a first layer attached to the handle and a second layer that temporarily holds the discrete component. The release layer is a heat-sensitive material. The release layer is a UV-sensitive material. The second layer is parallel to the first layer. The first layer is a permanent adhesive and the second layer is heat sensitive. The heat sensitivity of the second layer reduces adhesive strength in response to application of thermal energy. The heat sensitivity of the second layer increases adhesive strength in response to application of thermal energy. The UV photosensitivity increases adhesive strength in response to exposure to UV light. The UV photosensitivity reduces adhesive strength in response to exposure to UV light. The handle comprises a thickness between 49 and 801 microns. At least one side of the handle comprises a length between 100 and 600 microns. At least one side of the handle comprises a length between 300 and 800 microns. At least one side of the handle comprises a length between 400 and 600 microns.

[0098] In general, in one aspect, a method includes depositing an ultra-thin wafer on a handle substrate and releasing discrete components from the ultra-thin wafer, where the discrete components have an ultra-thin profile and the handle substrate has a thickness of at least 50 microns.

[0099] Implementations may include one or a combination of any two or more of the following features.

[0100] The method also includes attaching a release layer to the handle substrate such that the ultra-thin wafer is releasably attached to the release layer. Releasing the discrete components includes dicing the ultra-thin wafer. Dicing the ultra-thin wafer further includes dicing the handle substrate to form a diced handle substrate such that the discrete components are releasably attached to the handle substrate. The discrete components are sized to cover a surface of the diced handle substrate. The release layer is a heat sensitive material. The release layer is a UV sensitive material. The release layer includes first and second layers. The release layer includes a first layer attached to the handle and a second layer intended for deposition of the discrete components. The second layer is parallel to the first layer. The second layer is UV sensitive. The second layer is heat sensitive. The first layer is a permanent adhesive. The heat sensitivity of the second layer reduces adhesive strength in response to application of thermal energy. The heat sensitivity of the second layer increases adhesive strength in response to application of thermal energy. The UV photosensitivity increases adhesive strength in response to irradiation with UV light. The UV photosensitivity decreases adhesive strength in response to irradiation with UV light. The method also includes transferring the discrete component onto the handle substrate for contact with the device substrate. The method also includes releasing the discrete component from the handle substrate for depositing the discrete component onto the device substrate. The depositing the discrete component onto the device substrate includes bonding the discrete component to the device substrate. The releasing the discrete component from the handle is performed simultaneously with the bonding the discrete component to the device substrate. The releasing the discrete component from the handle is in response to the bonding the discrete component to the device substrate. The releasing the discrete component from the handle is caused by bonding the discrete component to the device substrate. The releasing the discrete component from the handle is completed after the bonding the discrete component to the device substrate. The discrete component is released from the handle by bonding with the device substrate.The bonding step further includes providing thermal energy or UV light for both bonding the discrete component to the substrate and releasing the discrete component from the handle. The handle substrate includes a thickness between 49 and 801 microns. The handle substrate remains in contact with the device substrate when releasing the handle substrate from the discrete component. The method further includes removing the handle substrate from the discrete component. The removing the handle substrate may include applying at least one of the following, or any combination of two or more thereof: a brush, a blade, compressed air, a vacuum force, vibration, a liquid jet, an electrostatic force, an electromagnetic force, or gravity. At least one side of the handle includes a length between 100 and 600 microns. At least one side of the handle includes a length between 300 and 800 microns. At least one side of the handle includes a length between 400 and 600 microns.

[0101] In general, in one aspect, a device includes a discrete component having an ultra-thin profile and a handle substrate releasably attached to the discrete component, the handle and the discrete component having a thicker profile than the discrete component.

[0102] Embodiments may include one or any combination of two or more of the following features. The apparatus also includes a release layer attached to the handle substrate such that the discrete components are releasably attached to the release layer. The release layer is a heat sensitive material. The release layer is a UV sensitive material. The release layer includes a first layer and a second layer. The release layer includes a first layer attached to the handle and a second layer intended for deposition of the discrete components. The second layer is parallel to the first layer. The second layer is UV sensitive. The second layer is heat sensitive. The first layer is a sensitive permanent adhesive. The heat sensitivity of the second layer reduces adhesive strength in response to heat exceeding a thermal parameter of the adhesive. The heat sensitivity of the second layer increases adhesive strength in response to heat exceeding a thermal parameter of the adhesive. The UV sensitivity increases adhesive strength in response to exposure to UV light. The UV sensitivity reduces adhesive strength in response to exposure to UV light. The handle substrate includes a thickness between 49 and 801 microns. At least one side of the handle substrate comprises a length between 100 and 800 microns. At least one side of the handle substrate comprises a length between 300 and 800 microns. At least one side of the handle substrate comprises a length between 400 and 600 microns.

[0103] In general, in one aspect, a method includes applying a processing step that changes a material between a surface of an ultra-thin discrete component and a substrate to which the ultra-thin discrete component is attached to a state in which the material holds the discrete component on the substrate, and simultaneously changes a material that temporarily holds an opposing surface of the ultra-thin discrete component on a handle held by a chuck of a pick and place tool to a state in which the material no longer holds the discrete component on the handle.

[0104] Embodiments may include one or any combination of two or more of the following features: The method includes causing a change of state, which includes providing thermal energy, UV light, or both. The material that temporarily holds the opposing surface of the discrete component on the handle substrate includes a release layer including a first layer and a second layer. The material that temporarily holds the opposing surface of the discrete component on the handle substrate includes a release layer including a first layer attached to the handle and a second layer that temporarily holds the discrete component. The release layer is a heat sensitive material. The release layer is a UV sensitive material. The second layer is parallel to the first layer. The first layer is a permanent adhesive and the second layer is heat sensitive. The second layer is UV sensitive. The second layer is heat sensitive. The heat sensitivity of the second layer reduces adhesive strength in response to application of heat energy. The heat sensitivity of the second layer increases adhesive strength in response to application of heat energy. The UV sensitivity increases adhesive strength in response to application of UV light. The UV photosensitivity reduces adhesive strength in response to irradiation with UV light. The handle comprises a thickness between 49 and 801 microns. At least one side of the handle comprises a length between 100 and 600 microns. At least one side of the handle comprises a length between 300 and 800 microns. At least one side of the handle comprises a length between 400 and 600 microns.

[0105] In general, in one aspect, a method includes using a releasable layer to attach a handle substrate to a discrete component, and using a tool to hold the handle substrate and bring the discrete component into contact with an adhesive layer on the device substrate while the handle substrate is attached to the discrete component, The method also includes releasing the handle substrate from the discrete component such that the discrete component is attached to the device substrate with the adhesive layer, and withdrawing the tool from the handle substrate while the handle substrate remains in contact with the discrete component via the released releasable layer.

[0106] Implementations may include one or a combination of any two or more of the following features.

[0107] The method includes removing the handle substrate from contact with the discrete components. Removing the handle substrate from contact with the discrete components includes applying at least one of the following, or a combination of any two or more of the following: a brush, a blade, compressed air, a vacuum force, vibration, or gravity. The releasable layer is a heat sensitive material. The releasable layer is a UV sensitive material. The releasable layer includes first and second layers. The releasable layer includes a first layer attached to the handle and a second layer targeted for deposition of the discrete components. The second layer is parallel to the first layer. The second layer is UV sensitive. The second layer is heat sensitive. The first layer is a permanent adhesive. The heat sensitivity of the second layer reduces adhesive strength in response to application of thermal energy. The heat sensitivity of the second layer increases adhesive strength in response to application of thermal energy. The UV sensitivity increases adhesive strength in response to irradiation with UV light. The UV sensitivity reduces adhesive strength in response to irradiation with UV light. The step of releasing the discrete component from the handle occurs simultaneously with the step of attaching the discrete component to the device substrate. The step of releasing the discrete component from the handle is responsive to the step of attaching the discrete component to the device substrate. The step of releasing the discrete component from the handle is caused by attaching the discrete component to the device substrate. The step of releasing the discrete component from the handle is completed after the step of attaching the discrete component to the device substrate. The discrete component is released from the handle by attaching the discrete component to the device substrate.

[0108] Described herein are, among other things, new methods of packaging ultra-small and / or ultra-thin discrete components, such as ultra-small and / or ultra-thin semiconductor dies, including integrated circuits that are temporarily attached to a handle substrate so that the resulting assembly can be compatible with standard electronic packaging equipment, such as pick-and-place die bonders and other chip assembly equipment. Among other things, the methods and products described herein can be relatively simple, inexpensive, effective, and compatible with current systems. In that respect, these methods and products will open up new markets and expand current markets for technologies that include low-cost electronic devices.

[0109] As used herein, the term discrete component broadly includes any unit that is part of a product or electronic device, such as an electronic, electromechanical, or optoelectronic component, module, or system, for example any semiconductor material having circuitry formed on a portion of the semiconductor material.

[0110] As used herein, the term device substrate broadly includes any object that receives or onto which discrete components are assembled, such as a higher level assembly, such as a product or electronic device, electronic, electromechanical, or optoelectronic component, or system. In some examples, the device substrate can be a flexible organic substrate.

[0111] As used herein, the terms handle, handle substrate, temporary handle, or temporary handle substrate broadly include any rigid substrate, such as, for example, a blank silicon wafer, a glass or ceramic substrate, or a substrate made of a rigid polymer or composite material, a substrate made with a thickness or rigidity or both that exceeds the thickness or rigidity or both of the discrete components for temporary use for transferring the discrete components to a device substrate and / or for temporary use for supporting one or more discrete components.

[0112] As used herein, the term carrier or carrier substrate broadly includes any material that includes one or more discrete components, such as a collection of discrete components assembled by a manufacturer, such as a wafer including one or more semiconductor dies.

[0113] As used herein, the term transparent carrier broadly includes any material, such as, for example, glass or a transparent polymer, to which the discrete components are attached via a carrier release layer, and which is at least partially transparent to at least some wavelengths in the ultraviolet, visible, or infrared electromagnetic spectrum.

[0114] With respect to discrete components, the term ultra-thin, as used herein, broadly includes discrete components having a thickness that is incompatible with typical pick-and-place techniques, for example, having a thickness of 50 μm or less.

[0115] With respect to discrete components, the term ultra-miniature, as used herein, broadly includes discrete components having a size that is incompatible with typical pick-and-place techniques, for example having a maximum length of 300 μm / side or less.

[0116] As used herein with respect to wafers, the term ultra-thin broadly includes semiconductor wafers having a maximum thickness of, for example, 50 μm or less.

[0117] These and other aspects, features, embodiments, and advantages may be expressed as methods, apparatus, systems, components, means or steps for implementing a function, and in other ways and combinations thereof.

[0118] These and other aspects, features, embodiments, and advantages will become apparent from the following description, and from the claims. [Brief description of the drawings]

[0119] [Figure 1A] FIG. 1 is a diagram of discrete components on a device substrate. [Figure 1B] FIG. 1 is a diagram of discrete components on a device substrate. [Diagram 2] FIG. 1 is a schematic side view of a handle assembly including ultra-small and ultra-thin bare discrete components and a handle substrate. [Diagram 3] FIG. 1 is a schematic side view of a handle assembly including ultra-small and ultra-thin bare discrete components and a handle substrate. [Figure 4] FIG. 1 is a schematic side view of a handle assembly including ultra-thin bare discrete components and a handle substrate. [Diagram 5] 1 is a flowchart. [Figure 6] Both Figures 6A and 6B are diagrams of wafer thinning. [Figure 7] FIG. 1 is a diagram of an ultra-thin wafer mounted on a handle substrate. [Figure 8A] FIG. 2 is a diagram of dicing an ultra-thin wafer. [Figure 8B] FIG. 2 is a diagram of dicing an ultra-thin wafer. [Figure 9] FIG. 1 is a diagram of the transfer of a diced ultra-thin wafer. [Figure 10] FIG. 1 is a diagram of the transfer of a diced ultra-thin wafer. [Figure 11] FIG. 1 is a diagram of the transfer of a diced ultra-thin wafer. [Figure 12] FIG. 1 is a diagram of the transfer of a diced ultra-thin wafer. [Figure 13] FIG. 1 is a diagram of the transfer of a diced ultra-thin wafer. [Figure 14] FIG. 1 is a diagram of pick-and-place assembly of discrete components. [Figure 15] FIG. 1 is a diagram of a laser-assisted non-contact method for transferring discrete components that are ultra-thin and / or ultra-small. [Figure 16] FIG. 3 is a schematic diagram illustrating an example of a packaging process for discrete components using the handle assembly of FIG. 2, where the active surface of the ultra-small and ultra-thin bare discrete components faces away from the device substrate. [Figure 17] FIG. 2 is a schematic side view of a handle substrate prior to attachment of discrete components. [Figure 18] 1 is a schematic side view of a transfer assembly and a device substrate assembly. [Figure 19] FIG. 3 is a schematic diagram illustrating another example of a packaging process for discrete components using the handle assembly of FIG. 2, where the active surface of the ultra-small and ultra-thin bare discrete components faces away from the device substrate. [Figure 20] FIG. 2 is a schematic side view of a handle substrate prior to attachment of discrete components. [Figure 21] FIG. 1 is a schematic side view of a multiple handle substrate assembly. [Figure 22] FIG. 4 is a schematic diagram illustrating an example of a packaging process for discrete components using the handle assembly of FIG. 3, where the active surface of the ultra-small and ultra-thin bare discrete components faces the device substrate. [Diagram 23] 1 is a schematic side view of a transfer assembly and a device substrate assembly. [Figure 24] FIG. 2 is a schematic side view of a handle substrate prior to attachment of discrete components. [Diagram 25] FIG. 5 is a schematic diagram illustrating an example of a packaging process for discrete components using the handle assembly of FIG. 4, where the active surface of the ultra-thin bare discrete components faces the device substrate. [Figure 26] 1 is a schematic side view of a transfer assembly and a device substrate assembly. [Figure 27] FIG. 1 is a process flow diagram. [Figure 28] FIG. 1 is a process flow diagram. [Figure 29] FIG. 1 is a process flow diagram. [Diagram 30] FIG. 1 is a process flow diagram. [Diagram 31] FIG. 26 is a schematic diagram illustrating an example of a process for use in the packaging process of the discrete components of FIG. [Diagram 32] FIG. 1 is a process flow diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0120] Described herein are, among other things, new methods for packaging highly flexible and / or tiny (e.g., imperceptible) discrete components. For example, the discrete components may be semiconductor dies containing integrated circuits. Such flexible and imperceptible discrete components are ultra-thin and / or ultra-small, offering flexibility and low cost that are beneficial for a wide range of applications, but also currently incompatible with conventional packaging techniques, such as, for example, pick-and-place equipment. In particular, the methods and products described herein are optimized to handle such ultra-thin and / or ultra-small discrete components in combination with conventional pick-and-place equipment. In that regard, these methods and products can result in reduced manufacturing costs for electronic products while supporting higher packaging speeds than are possible with conventional discrete components and pick-and-place equipment.

[0121] Discrete components are packaged according to a series of process steps, each of which has one or more possible approaches. These approaches can be combined with mix-and-match schemes to obtain a variety of processes for packaging ultra-small or ultra-thin discrete components. In some of these processes, the discrete components are temporarily attached to a handle substrate so that the resulting assembly can fit into standard electronic packaging equipment, such as a pick-and-place die bonder or other chip assembly equipment. In some of these processes, laser-assisted non-contact transfer methods are used to transfer discrete components that cannot fit into standard electronic packaging equipment. Notably, the methods and products described herein can be relatively simple, inexpensive, effective, and compatible with current systems. In that respect, these methods and products will open up new markets and expand current markets for technologies that include low-cost electronic devices.

[0122] The processes described herein can enable packaging of discrete components that are ultra-small or ultra-thin or both, e.g., discrete components that are too thin or too small or both for standard integrated circuit packaging equipment or approaches. Discrete components can be formed ultra-thin, e.g., having a maximum thickness of 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 10 μm or less, and 5 μm or less, ultra-small, e.g., having a maximum length or width dimension of 300 μm / side or less, 250 μm / side, 200 μm / side, 150 μm / side, and 100 μm / side, or both ultra-thin and ultra-small. As such, the dimensions of discrete components make current large scale integrated circuit packaging techniques, such as mechanical pick-and-place systems, ineffective (e.g., due to physical limitations, high cost, inefficiencies, and / or slow production rates), if not completely impossible, to package discrete components or similarly sized discrete components.

[0123] 1A, using one or more processes described herein, discrete components 10 that are ultra-thin, tiny, or both, can be placed on a device substrate 12 for packaging into an electronic device. The device substrate 12 can be a substrate compatible with integrated circuit packaging, such as a printed circuit board, a plastic casing, a ceramic substrate, a flexible circuit, or other device substrate. The discrete components 10 can be mechanically bonded, electrically connected, or both, to the device substrate 12 via attachment elements 14, such as, for example, a curable conductive or non-conductive adhesive (discussed below).

[0124] The discrete component 10 includes an active surface 102 on which one or more integrated circuit devices are formed. In some examples, the active surface 102 can include a passivation layer (not shown). In the example of FIG. 1A, the discrete component 10 is positioned on the device substrate 12 such that the active surface 102 of the discrete component 10 faces away from the device substrate 12 (sometimes referred to herein as a "face-up" position). When positioned on the device substrate 12 in a face-up position, the discrete component 10 can be electrically connected to other components on the device substrate 12 using approaches such as wire bonding, tape automated bonding (TAB), screen printing, direct write, or other methods. The backside of the discrete component is bonded to the device substrate using approaches such as eutectic alloys, solder, adhesives such as conductive or non-conductive epoxies, polyamide, or other materials or methods.

[0125] 1B, in some examples, using one or more of the processes described herein, the discrete components 10 can be placed on the device substrate 12 such that the active surface 102 of the discrete components 10 faces the device substrate 12 (sometimes referred to herein as a "face-down" position or a "flip-chip" configuration). When packaged in a flip-chip configuration, the discrete components can be electrically connected to other components on the device substrate using flip-chip assembly methods such as conductive adhesives or soldering.

[0126] As shown in Figures 2 and 3, in some examples, a handle assembly 100 including a discrete component 10 and a handle substrate 108 is manipulated to place the discrete component 10 on a device substrate. The discrete component 10 includes an active surface 102, which includes an integrated circuit device. The active surface 102 may also include a passivation layer (not shown). The discrete component 10 is releasably attached to the handle substrate 108 via attachment to a handle release layer 105 having a first surface 104 exposed to the discrete component 10 and a second surface 106 exposed to the handle substrate 108. The handle release layer 105 is discussed in more detail below.

[0127] In Fig. 2, the discrete component 10 is oriented with the active surface 102 facing the handle substrate 108. Such a configuration is advantageous when the discrete component is expected to be placed in a face-up position on the device substrate and electrically connected to other components on the device substrate using means and materials typically used for such connections, such as wire bonding, tape automated bonding (TAB), screen printing, direct write, or other methods. The backside of the discrete component is bonded to the device substrate using means and materials typically used for such attachment, such as eutectic alloys, solders, adhesives such as conductive or non-conductive epoxies, polyamides, or other suitable material and methods.

[0128] As described below, the integrated packaging method can alternatively produce discrete components with alternative active surface orientations. For example, as shown in Figure 3, a handle assembly 101 can include a discrete component 10 having an active surface 102 exposed or oriented away from a handle substrate 108. Such an orientation is advantageous when the discrete component 10 is expected to be electrically connected to components such as conductors on a device substrate, for example as shown in Figure 24, using a method known as flip-chip assembly.

[0129] In some embodiments, the handle substrate 108, e.g., a blank silicon wafer, glass, ceramic, or other inorganic or organic material, extends beyond the discrete components 10 and is sized and configured to fit into current pick-and-place systems. In some cases, one or more circuits are placed on an oversized handle substrate, and each individual handle is cut to size. Typically, the handle substrate 108 can have a length of 300 μm / side or more, preferably 400-600 μm / side, and a thickness of more than 50 μm, e.g., between 100-800 μm, greater than 50 μm. In these cases, the pick-and-place system may not be able to effectively transfer the discrete components 10, but the pick-and-place system will be able to transfer the discrete components 10 as long as they are attached to a sufficiently sized and configured handle substrate. As such, however, the absence of standard deployment means of the pick-and-place system, e.g., vacuum force, will prevent the system from releasing only the discrete components, but rather the assembly of handle and discrete components. However, among other advantages, the characteristics of the attachment means, and in particular their relative relationships to one another between the discrete component, the handle substrate, and the device substrate, are selectable and customizable, such that the pick-and-place system releases the discrete component from the handle substrate and attaches it to the device substrate while retaining control over the handle substrate.

[0130] In some embodiments, the discrete components 30 may have a certain size, but remain too thin to fit into current packaging technology. In these cases, as shown in FIG. 4, the handle assembly 103 may include an ultra-thin discrete component 30 attached to a handle substrate 308 having a similar length as the discrete components 30. Thus, the handle assembly 103 is thick enough to fit into a pick-and-place system. The properties of the handle release layer 305, including the second surface 306 and the first surface 304, are generally similar to those described with reference to FIGS. 2 and 3.

[0131] Described herein are several processes that can be used to place discrete components that are ultra-thin, ultra-small, or both, on a device substrate in a face-up or face-down position. The processes described herein follow a general flow that includes several general process steps, each of which can be accomplished by one or more different approaches. The processes described herein are established by a "mix and match" approach between the general process steps, and an approach for each of the general process steps. Some processes described herein include all of the general process steps; some processes include less than all of the general process steps.

[0132] With reference to FIG. 5, a general flow (200) for placing discrete components, which may be ultra-thin, ultra-small, or both, on a device substrate includes the following general process steps: wafer processing (202), wafer preparation (204), wafer transfer (206), component transfer (208), component interconnection (210), and handle removal (212). Each of these general process steps is described briefly here and in more detail later in this specification. In some examples, the process steps may occur in a different order than that shown in FIG. 5. For example, wafer preparation 204 may occur after wafer transfer 206. In some examples, one or more of the process steps may be split into multiple process steps, which may occur at different times than the order shown in FIG. 5. For example, wafer preparation 204 may be split into a first sub-step that occurs before wafer transfer 206 and a second sub-step that occurs after wafer transfer 206.

[0133] Wafer processing (202) involves producing or obtaining a wafer having a number of discrete components fabricated thereon. Wafer processing may be referred to herein as discrete component fabrication. The discrete components are fabricated on the wafer using semiconductor processing techniques, such as thin film processing, on a semiconductor substrate, such as a bulk silicon substrate, a silicon-on-insulator substrate, a germanium substrate, a gallium arsenide substrate, a sapphire substrate, or another type of semiconductor substrate.

[0134] In some examples, discrete components fabricated on a wafer are bumped to make the discrete components compatible with a flip-chip configuration. The discrete components can be bumped by stud bumping, electroless nickel-gold plating, solder balls, solder paste printing, solder electroplating, or other approaches. In some examples, the discrete components are bumped at a later point in the general process.

[0135] Wafer preparation (204) includes aspects such as thinning the wafer, mounting the wafer on a handle substrate, mounting the wafer on a dicing tape, mounting the wafer on a transparent carrier, dicing the wafer into individual discrete components, or a combination of any two or more of these aspects. A transparent carrier is a material, such as glass or a transparent polymer, to which the discrete components are attached via a carrier release layer, and which is at least partially transparent to at least some wavelengths in the ultraviolet, visible, or alternatively infrared electromagnetic spectrum. In some processes described herein, a handle substrate is not used.

[0136] Wafer transfer (206) involves transferring the diced wafer to a transparent carrier or repackaging the diced wafer in a die carrier such as a waffle pack, gel pack, or another type of die carrier. In some processes described herein, the wafer transfer process step is not performed.

[0137] Component transfer (208) involves transferring individual discrete components onto target locations on the device substrate, which can be done by a pick-and-place approach, a laser-assisted non-contact transfer method, another transfer method, or a combination of transfer methods.

[0138] Component interconnection (210) may include, for example, bonding a discrete component to a device substrate such that the discrete component is electrically connected to circuitry on the device substrate.

[0139] Handle removal (212) involves releasing the handle substrate from the bonded discrete components and removing the detached handle substrate from the device substrate. In processes that do not use a handle substrate, the handle removal process step is not performed.

[0140] Each of the general process steps illustrated in FIG. 5 may have one or more aspects, one or more of which may be performed for each specific process described herein.

[0141] [Wafer preparation] In the wafer preparation process step, the wafer is thinned and diced to obtain discrete components having a desired size and thickness. In some of the processes described herein, the wafer preparation can include mounting the wafer on a handle substrate. In some examples, the wafer preparation process step can occur before the wafer transfer process step (described below). In some examples, the wafer preparation process step can occur after the wafer transfer process step. In some examples, the wafer preparation process step can include multiple sub-steps, one or more of which can occur before the wafer transfer process step and one or more of which can occur after the wafer transfer process step.

[0142] Wafer preparation can include wafer thinning. Referring to Figures 6A and 6B, a wafer 300 having a number of discrete components 10 is thinned to a desired thickness. The wafer 300 can be thinned (meaning to reduce the thickness of the wafer 300) by any of a variety of semiconductor processing techniques, such as mechanical grinding, chemical mechanical planarization (CMP), wet etching, atmospheric downstream plasma etching (ADP), reactive ion etching (RIE), dry chemical etching (DCE), vapor phase etching (VPE), or any combination thereof, such as mechanical grinding followed by chemical mechanical polishing. The initial thickness of the wafer 300 before thinning can be between about 0.1 mm and about 1 mm, such as between about 0.2 mm and about 0.8 mm, such as about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, or another thickness, and can be thinned to a thickness of about 50 μm or less, about 40 μm or less, about 30 μm or less, about 20 μm or less, about 10 μm or less, about 5 μm or less, or another thickness.

[0143] In some examples, the wafer 300 can be thinned to a thickness of about 50 μm using mechanical grinding techniques, such as back-grinding. Generally, however, as the wafer thickness is reduced, the wafer 300 becomes more susceptible to damage from mechanical grinding due to the fragility of the thin wafer. To reduce the risk of damaging the wafer, non-contact material removal processes can be used to reduce the wafer thickness beyond that achievable by conventional mechanical grinding processes. For example, to achieve a wafer thickness of 25 μm or less, a non-contact material removal process, such as reactive ion etching (RIE), vapor phase etching, or other suitable process, can be used to fabricate the thin wafer.

[0144] In some examples, wafer thinning to a thickness of about 50 μm can be accomplished by mechanical backgrinding and subsequent polishing. During the thinning process, the wafer is temporarily bonded to a support substrate 302, such as a thicker wafer (e.g., a 3M Wafer Support System®). In the backgrinding and polishing process, the active layer 310 on the top surface of the wafer 300, on which the integrated circuits are formed, faces down towards the support substrate 302. Following wafer thinning, the thinned wafer is removed from the support substrate 304.

[0145] Referring to Figure 7, wafer preparation can include mounting the thinned wafer 300 on a handle substrate 108 to form a wafer handle assembly 400. The thinned wafer 300 can be mounted on the handle substrate in a face-up configuration (as shown in Figure 7) or a face-down configuration. The handle substrate 108 can be, for example, a blank silicon wafer, glass, ceramic, or another inorganic or organic material. The handle substrate can be sized to be compatible with standard integrated circuit processing techniques such as pick-and-place systems. For example, the handle substrate 108 can have a thickness greater than about 50 μm, such as between about 100 μm and about 800 μm, such as about 100 μm, about 150 μm, about 200 μm, about 250 μm, about 300 μm, about 350 μm, about 400 μm, about 450 μm, about 500 μm, about 550 μm, about 600 μm, about 650 μm, about 700 μm, about 750 μm, about 800 μm, or another thickness.

[0146] The thinned wafer 300 can be releasably attached onto the handle substrate 108 via attachment to a handle release layer 105. The handle release layer provides adhesion between the wafer 300 and the handle substrate 108, which can be released by application of a stimulus such as ultraviolet (UV) light, high temperature, normal or shear mechanical force, or another stimulus, or a combination of any two or more thereof.

[0147] In some examples, the handle release layer 105 is a double-sided handle release layer formed of a composite of multiple sub-layers (e.g., a first layer and a second layer). The double-sided handle release layer 105 and one or more sub-layers (if present) can include one or more surfaces (e.g., an interior surface or an exterior surface, etc.). The double-sided handle release layer 105 includes a first surface 104 exposed to the discrete component 10 and a second surface 106 exposed to the handle substrate 108. In some examples, the handle release layer 105 is a double-sided heat or UV release tape known to be compatible with wafer attachment for wafer dicing or thinning. In such a tape, the second surface 106 includes a pressure sensitive adhesive and the first surface 104 can include a UV or heat release material. Exemplary release materials compatible with semiconductor materials are known and can be selected based on the desired adhesion properties.

[0148] In some examples, the handle release layer 105 is a single layer such that the first side 104 and the second side 106 are the same material. Such materials may include, for example, spin-on thermal release materials for temporary wafer bonding, such as Valtech's Valtron® Heat Release Epoxy System or Logitech's OCON-196 Thin Film Bonding Wax. Other examples of thermal release materials include ethylene vinyl acetate (EVA) copolymer films, such as Dynatex's WaferGrip adhesive film. Other exemplary materials include UV release adhesives, such as polymers with photofunctional groups that readily change their chemical structure upon exposure to UV light energy. Other examples of materials for the single layer handle release layer 105 include sublimable materials that undergo a transition from a solid state directly to a gas phase without passing through an intermediate liquid phase under the influence of a stimulus.

[0149] In general, the handle release layer 105 is formed of a material that is mechanically responsive to an applied stimulus. In some examples, the handle release layer undergoes a mechanical change in response to the stimulus. For example, the handle release layer may lose adhesion as a result of a change in surface morphology caused by the application of the stimulus. An exemplary handle release layer may be formed of a material that transitions from a smooth, highly adhesive adhesive to a rough, less adhesive adhesive in response to heat, ultraviolet light, or another type of stimulus. In some examples, the handle release layer undergoes a phase transition in response to the stimulus and loses adhesion as a result of a physical change in state. The transition may be from solid to liquid (melting) or from solid to gas (sublimation). In some examples, the handle release layer undergoes a chemical change in response to the stimulus and loses adhesion as a result of a change in its chemical structure or composition. Some materials undergo thermal decomposition, or thermolysis, which is chemical decomposition caused by heat. Some materials undergo photolysis, which is decomposition caused by the absorption of light.

[0150] In some examples, the bond strength between the handle release layer 105 and the wafer 300 and between the handle release layer 105 and the handle substrate 108 are selected, for example, such that when the wafer 300 is attached to the first side 104, the bond strength of the attachment is weaker than the bond strength between the second side 106 and the handle substrate 108, respectively. The bond strength between the wafer 300 and the first side 104 can also be selected to be weaker than the bond strength between the discrete components 10 and the device substrate, described below. For example, in some cases, the handle release layer 105 can be a material that has a melting temperature lower than the temperature required to bond the discrete components 10 and the device substrate, described below. Examples include wax or similar materials.

[0151] In another example, the handle release layer 105 is selected such that the adhesion features on the first side 104 are independently controllable relative to the attachment features on the second side 106. This provision helps ensure that the wafer 300 (or individual discrete components 10) can be selectively released from the handle substrate 108 without having to release the handle release layer 105 from the handle substrate 108.

[0152] In other cases, for example, the handle release layer 105 may alternatively or additionally comprise a double coated thermal release tape (such as REVALPHA® double coated thermal release tape by Nitto®) that includes a pressure sensitive adhesive layer and a thermal release adhesive layer. In some cases, the first side 104 may include a thermal release adhesive layer and the second side 106 may include a pressure sensitive adhesive. At least upon application of thermal energy, the bond strength between the wafer 300 (or individual ultra-thin or ultra-small discrete components 10) and the handle release layer 105 may be weaker compared to the bond strength between the handle release layer 105 and the handle substrate 108. In this way, a force applied to the wafer 300 (or individual ultra-thin or ultra-small discrete components 10) in a direction away from the handle substrate, such as a tensile force and / or a shear force in a direction away from the handle substrate 108, can freely remove the wafer 300 or individual ultra-thin or ultra-small discrete components 10 from the handle substrate 108 without removing the handle release layer 105, which remains attached to the handle substrate 108.

[0153] The attachment means between the discrete components 10 and the handle substrate 108 is generally described as an adhesive tape, although other arrangements could be possible. For example, vacuum or electrostatic forces could be used to temporarily form this attachment. As with the handle release layer 105, the attachment means and characteristics such as bond strength could be selected such that the bond strength between the discrete components and the substrate is greater than the bond strength between the discrete components and the handle when the discrete components are bonded to the substrate.

[0154] In some cases, it is desirable to provide the handle release layer 105 to be relatively thin, for example, having a thickness of less than 20 μm, preferably less than 10 μm, and in some cases less than 5 μm. The use of a thin handle release layer allows the use of certain advantageous chip dicing methods and improves chip quality after dicing and transfer to a substrate. The use of a thicker handle release layer may contribute to chipping or cracking of the die during the dicing process.

[0155] 8A and 8B, wafer preparation can include dicing the wafer handle assembly 400 into handle assemblies 500 (sometimes referred to as wafer singulation) or dicing a wafer without a handle substrate into discrete parts. The wafer handle assembly is a wafer attached to a handle substrate. The handle assemblies are individual discrete parts attached to a portion of the handle substrate. The wafer handle assembly can be fully or partially diced by dry or wet etching, plasma dicing, mechanical cutting (as shown in FIG. 8A), laser ablation, stealth dicing (as shown in FIG. 8B), or another dicing technique. In some examples, the wafer handle assembly 400 can be diced by approaching the wafer handle assembly 400 from the front side of the wafer handle assembly 400 (e.g., the side where the wafer is located). In the example of FIG. 8A, the wafer handle assembly 400 is partially diced directly by mechanical cutting with a blade 502. In some examples, the wafer handle assembly 400 can be diced by approaching the wafer handle assembly 400 from the rear side of the wafer handle assembly 400 (e.g., the side where the handle substrate 108 is located) with a dicing tool. In the example of Figure 8B, the wafer handle assembly 400 is indirectly diced by laser micromachining (sometimes called laser stealth dicing) with a laser beam 504 incident on the backside of the wafer handle assembly 400. In some examples, mechanical cutting and laser stealth dicing are used sequentially to completely dice the wafer handle assembly 400.

[0156] In some instances, a wafer-handle assembly 400 including a thinned wafer and a handle substrate can be diced (e.g., as shown in Figures 8A and 8B). In some instances, the thinned wafer is not attached to the handle substrate during dicing.

[0157] In some instances (e.g., as shown in Figures 8A and 8B), the wafer handle assembly 400 or wafer can be adhered to a dicing tape 506 for dicing. The dicing tape 506 can have a backing material of polyvinyl chloride (PVC), polyolefin, polyethylene, or another material, and an adhesive surface to which the wafer handle assembly or wafer is adhered.

[0158] In some instances (not shown), wafer transfer (described below) may occur prior to wafer dicing. For example, the wafer handle assembly or wafer may be attached to a transparent carrier, and the attached wafer handle assembly or wafer is diced. The transparent carrier may be formed of a material, such as glass or a transparent polymer, that is at least partially transparent to at least some wavelengths in the ultraviolet, visible, or infrared electromagnetic spectrum. The transparent carrier may have a layer of dynamic release layer (DRL) disposed on its surface, as described in WO 2012 / 033147, the contents of which are incorporated herein by reference in their entirety.

[0159] In some instances, the wafer may be partially diced prior to the wafer transfer process step, and dicing may be completed after the wafer transfer process step (described below).

[0160] [Wafer transfer] In the wafer transfer process step, a partially or fully diced handle assembly or an undiced wafer or wafer-handle assembly is transferred from the dicing tape to a transparent carrier or die carrier, such as a waffle pack, gel pack, or another type of carrier. Various approaches can be used for wafer transfer, sometimes in combination with the dicing process.

[0161] The transparent carrier 600 may be formed of a transparent material, such as glass or a transparent polymer, that is at least partially transparent to at least some wavelengths in the ultraviolet, visible, or infrared electromagnetic spectrum. The transparent carrier may have a carrier release layer disposed on a surface thereof, including a dynamic release layer (DRL) 604, an adhesive layer (not shown), or both layers.

[0162] 9, in the wafer transfer approach 501, the diced handle assembly 500 or discrete components are transferred from a dicing tape 506 onto a transparent carrier 600 or die carrier. The diced handle assembly 500 or discrete components are removed from the dicing tape 506 using suction provided by, for example, a vacuum chuck 602. The transparent carrier 600 or die carrier is brought into contact with the diced handle assembly 500 or undiced wafer or wafer handle assembly that is sucked onto the vacuum chuck 602. The suction force is removed and the handle assembly 500 or undiced wafer or wafer handle assembly is transferred onto the transparent carrier 600 or die carrier.

[0163] Referring to FIG. 10, in the wafer transfer approach 320, the diced handle assembly 500 or discrete components are transferred from a dicing tape 506 onto a transparent carrier 600 or die carrier. The wafer or wafer handle assembly is adhered to the dicing tape and diced into the handle assembly 500 or discrete components. The dicing tape 506 is formed of a material that undergoes adhesive degradation in response to a stimulus such as heat or light. For example, the dicing tape 506 may be an ultraviolet (UV) release adhesive that undergoes adhesive degradation when exposed to UV light. The UV dicing tape is exposed to ultraviolet light 508, weakening the adhesive between the diced handle assembly or discrete components. The vacuum chuck 510 is covered with a material 512 that undergoes adhesive degradation in response to a stimulus such as heat or light. For example, the vacuum chuck 510 can be covered with a thermal release tape 512 (such as REVALPHA® double-sided thermal release tape by Nitto®) and a vacuum is drawn to hold the thermal release tape 512 in place. The diced handle assembly 500 or discrete components are removed from the UV dicing tape 506 by contact with the tape-covered vacuum chuck 510. In some instances, the diced handle assembly 500 or discrete components are removed from the dicing tape 506 because the thermal release tape 512 adheres to the diced handle assembly 500 or discrete components with greater adhesion than the weakened adhesion between the pre-exposed UV dicing tape 506 and the diced handle assembly 500 or discrete components. The dicing tape 506 is peeled off, leaving the handle assembly 500 or discrete components adhered to the thermal release tape 512.

[0164] The transparent carrier 600 with the dynamic release layer disposed thereon is contacted with the diced handle assembly 500 or discrete components adhered to the thermal release tape 512 on the vacuum chuck 510. For example, the transparent carrier 600 can be placed on top of the diced handle assembly 500 or discrete components and weighted for strong contact. Positive pressure can be applied to the vacuum chuck 510 to push the thermal release tape 512 away from the chuck 510, further pressing the diced handle assembly or discrete components against the dynamic release layer of the transparent carrier 600.

[0165] The stack including the transparent carrier 600, the diced handle assemblies 500 or discrete components, and the thermal release tape 512 is removed from the vacuum chuck 510 and heated to a temperature at which the thermal release tape loses some or all of its adhesive strength (referred to as the characteristic temperature of the thermal release tape). The thermal release tape 512 is then peeled off, leaving the diced handle assemblies 500 or discrete components on the transparent carrier 600.

[0166] The wafer transfer approach 320 can be used as long as the characteristic temperature of the thermal release tape is lower than the temperature that would melt, flow or degrade the handle release layer 105 of the handle assembly. Losses can also be mitigated by providing uniform contact between the discrete components or handle assemblies and the dynamic release layer on the transparent carrier, for example, by providing a flat vacuum chuck and flat surface of the dynamic release layer, or by providing positive pressure from the vacuum chuck for better contact. In some cases, the accuracy of placing the discrete components or handle assemblies on the transparent carrier can be improved by lifting the thermal release tape straight up as it is removed.

[0167] 11, in the wafer transfer approach 370, the wafer 300 or wafer handle assembly is adhered to a transparent carrier 600 via a material 374 with controllable adhesive force. For example, the transparent carrier 600 can include both a dynamic release layer and a UV or heat release adhesive, or can include only a UV or heat release adhesive. The wafer 300 or wafer handle assembly is diced (372) directly onto the transparent carrier 600. The material 374 with controllable adhesive force has a strong enough adhesive force to allow the wafer 300 or wafer handle assembly to be securely attached to the transparent carrier 600 during dicing.

[0168] After dicing is complete, the material 374 with controllable adhesion is exposed to a stimulus (376), such as heat or ultraviolet light, resulting in a decrease in the adhesion of the material 374. The adhesion level of the material 374 after exposure can be controlled by controlling parameters of the stimulus, such as the exposure intensity (e.g., ultraviolet light intensity or temperature), exposure time, or other stimulus parameters. For example, the adhesion of the material 374 can be decreased to a level compatible with the laser-assisted non-contact transfer method 800 described below.

[0169] The wafer transfer approach 350 simplifies the process flow by eliminating the part transfer process (described below), and can improve process yields using the wafer transfer approach 350 because there is no chance of losing discrete components or handle assemblies during part transfer without the part transfer process.

[0170] 12, in a wafer transfer approach 550, the wafer or wafer handle assembly 400 is partially diced (552), for example using partial blade dicing (as shown), laser dicing, wet etching, or another approach. Partial dicing removes passivation layers and metal from spaces (sometimes called streets) between discrete components on the wafer or wafer handle assembly 400, leaving a small amount of material (e.g., less than about 20 μm, such as about 5 μm, about 10 μm, about 15 μm, about 20 μm, or another amount) at the bottom of each dicing street. Partial dicing facilitates subsequent non-contact dicing, such as plasma dicing.

[0171] The partially diced wafer or wafer handle assembly is transferred (554) to a transparent carrier 600 having a dynamic release layer disposed thereon, for example using a vacuum chuck. Dicing is completed on the transparent carrier 600 using a non-contact approach (556), such as plasma dicing or wet etching. In the example of FIG. 12, the wafer handle assembly 400 is partially diced on a dicing tape and then fully diced on the transparent carrier; in some examples, the wafer handle assembly 400 is partially diced while attached to the transparent carrier 600 and then fully diced using a non-contact approach. In some cases, the wafer transfer approach 550 can be more efficient for dicing and transferring wafers than wafer handle assemblies or other thick parts. For example, the wafer transfer approach 550 may be used with the laser enabled packaging process 150 described below.

[0172] 13, in the wafer transfer approach 570, the wafer or wafer handle assembly 400 is fully diced on a dicing tape. For example, a two-step dicing process can be used in which the wafer or wafer handle assembly 400 is partially diced (572) using a dicing blade and then fully diced (574) using a stealth dicing approach. The diced discrete components or handle assemblies are transferred (576) to a vacuum chuck covered with a thermal release tape (e.g., Revalpha) and released (578) to a transparent carrier 600 as described above for the wafer transfer approach 320.

[0173] In addition to or instead of the dynamic release layer, the transparent carrier includes a material with controllable adhesion 580. Once the diced discrete components are attached to the transparent carrier, the material with controllable adhesion 580 is exposed 582 to a stimulus as described above for the wafer transfer approach 370 to reduce the adhesion of the material 580 to a level compatible with the laser-assisted non-contact transfer method 800 described below.

[0174] The wafer transfer approach 570 allows for less loss of discrete components or handle assemblies and allows for precise control of the laser assisted non-contact transfer method 800 via control of the adhesion level of the material 580 .

[0175] In the wafer transfer approach, a pick-and-place tool is used to transfer the handle assemblies or discrete components to a transparent carrier. In this approach, the handle assemblies or discrete components are repositioned on the transparent carrier in a desired arrangement, e.g., a rectangular array, allowing for simplification of the placement algorithm. This approach also improves downstream yields, since it allows for only "good" handle assemblies or discrete components to be transferred. This wafer transfer approach may be limited to handle assemblies or discrete components with a size that fits into the pick-and-place equipment, and may have a lower throughput compared to other wafer transfer approaches. This wafer transfer approach may be useful for prototyping, for example, in processes where individual discrete components are thinned and prepared for laser transfer.

[0176] Some processes described herein do not include a wafer transfer process step, for example, a process in which the wafer is mounted on a transparent carrier before dicing does not include a wafer transfer process step.

[0177] [Parts transfer] In the component transfer process step, individual discrete components are placed onto target locations on a device substrate.

[0178] Before the discrete components are placed on the device substrate, the device substrate or the discrete components or both may be provided with attachment elements that facilitate attachment, such as adhesion, electrical connection, or both, between the discrete components and the device substrate. The attachment elements may be a material that is curable in response to an applied stimulus, such as a material that is thermally curable, curable upon exposure to ultraviolet (UV) light, curable upon exposure to mechanical pressure, or otherwise curable. The attachment elements may be a conductive material, such as a conductive epoxy, a conductive paste, such as a conductive paste including metal (e.g., silver) or metal-coated particles in the paste, a solder paste, or another conductive material. The attachment elements may be a non-conductive material, such as Ablebond 8008NC (Henkel Electronic Materials, Irvine, Calif.). The attachment elements may be a film, such as an anisotropic conductive film or a non-conductive die attach film.

[0179] In some examples, the mounting elements can be anisotropic conductive material that, when cured, is conductive in only one direction or in less than all directions. For example, the mounting elements can be anisotropic conductive paste, such as Ablestik ACP-3122 (Henkel Electronic Materials, Irvine, Calif.), that is conductive in the vertical direction between the discrete components and the underlying device substrate, but not in the horizontal direction parallel to the surface of the device substrate. The anisotropic conductive mounting elements can be uniformly distributed across the device substrate such that the discrete components can be transferred onto the device substrate without precise alignment.

[0180] Referring to FIG. 14, in some examples, the transfer of the discrete components onto the device substrate is accomplished by a pick-and-place approach 700. Although the pick-and-place approach may not be effective in transferring ultra-thin or ultra-small discrete components, it can be used when the discrete components are attached to a larger or thicker handle substrate (in some cases, the individual discrete components attached to the handle substrate are referred to as handle assemblies). For example, the pick-and-place approach can be used to transfer handle assemblies having a side length of at least about 300 μm, handle assemblies having a side length of one millimeter or several millimeters or tens of millimeters. The pick-and-place approach can be used to transfer handle assemblies having a thickness greater than about 50 μm, for example, a thickness between about 100 μm and about 800 μm.

[0181] The pick and place approach 700 includes a tool 702 that transfers a handle assembly 500 onto a device substrate 704. The tool 702 lifts the handle assembly 500, for example, by applying suction to the handle substrate 108 of the handle assembly 500. The tool 702 places the handle assembly 500 directly onto a mounting surface 708 on the device substrate 704. The tool 702 then moves the handle assembly 500 towards the device substrate 704, for example, in a direction generally indicated by arrow 710, until the discrete component 10 contacts the mounting surface 708 on the device substrate 704.

[0182] 15, in some examples, component transfer is accomplished by a laser-assisted non-contact transfer method 800, sometimes referred to as tmSLADT (thermo-mechanical selective laser-assisted die transfer). In the tmSLADT method, the handle assembly 500 (as shown) or discrete components are adhered to a transparent carrier 600 having a dynamic release layer (DRL) 604 disposed thereon, for example, by an adhesive layer 802 as described above. The combination of the DRL 604 and adhesive layer 802 is sometimes referred to as the carrier release layer. The dynamic release layer (DRL) 604 is irradiated with light 804 from a laser. The DRL 604 absorbs the energy incident thereon from the laser light 804, causing it to heat up and partially vaporize, resulting in the formation of a blister 806. The blister 806 mechanically presses the handle assembly 500 against the mounting surface 708 of the device substrate 704. The tmSLADT method is described in WO 2012 / 142177, the contents of which are incorporated herein by reference in their entirety.

[0183] The adhesive force of the adhesive layer 802 is an important parameter in the tmSLADT process 800. The force balance during tmSLADT includes the force caused by the acceleration of the expanding blister 806, Fb=ma (where a is the acceleration of the expanding blister 806); the force of gravity, Fg=mg (where g is the gravitational constant); and the adhesive force Fa between the handle assembly 500 or discrete components and the adhesive layer.

[0184] If the handle assembly 500 or discrete component is attached to the DRL604 before laser irradiation, Fb (the force of the expanding blister) is zero and Fg is less than Fa (Fg < Fa). When the transfer is initiated (e.g., when laser irradiation begins), the sum of the force of the expanding blister and gravity exceeds the adhesive force (Fb + Fg > Fa) and the discrete component is transferred. Combining both conditions results in Fg < Fa < Fg + Fb, meaning that the adhesive force must be large enough to hold the handle assembly in place before transfer and less than the combination of inertia and gravity to allow removal of the discrete component or handle assembly during transfer.

[0185] The mass of the discrete component plays a role in both Fb and Fg, making it difficult to achieve these conditions for the transfer of ultra-small or ultra-thin discrete components. Further, the success of the transfer process generally is proportional to the difference between the forces promoting transfer (Fb and Fg) and the force opposing transfer (Fa).

[0186] The adhesive force between the discrete component or handle assembly and the DRL604 can be maintained at a level low enough, for example, to prevent the discrete component or handle assembly from falling due to gravity. However, a greater adhesive force to the DRL604 may be useful during the transfer of the wafer, wafer handle assembly, discrete component, or handle assembly from the dicing tape onto the transparent carrier 600. Thus, the transfer involves a balance between the adhesive force between the dicing tape and the DRL604 and the suction force of the transfer device (e.g., vacuum chuck). The wafer transfer approach described above is operable with various levels of adhesive force to the DRL604, providing flexibility to successfully perform tmSLADT transfer.

[0187] In some examples, component transfer can include both tmSLADT and pick-and-place approaches. For example, discrete components can be transferred to a handle substrate by a tmSLADT approach to form a handle assembly, and the handle assembly can be transferred to a device substrate by a pick-and-place approach. Conversely, the handle assembly can be transferred to a transparent carrier using a pick-and-place approach and then transferred to a device substrate by a tmSLADT approach.

[0188] The discrete components can be transferred onto the device substrate in a face-up orientation, such that the active surface of the discrete components faces upward (e.g., as shown in FIG. 1A), for example, for wire bonding applications. The discrete components can be transferred onto the device substrate in a face-down orientation, such that the active surface of the discrete components faces downward (e.g., as shown in FIG. 1B), for example, for flip chip assembly.

[0189] [Parts interconnection] In the component interconnect process step, the discrete components are bonded (e.g., mechanically bonded or electrically bonded, or both) to the device substrate. Referring again to FIG. 14, the attachment surface 708 on the device substrate includes attachment elements that facilitate attachment, such as adhesion, electrical connection, or both, between the discrete components and the device substrate. The attachment elements can be a material that is curable in response to an applied stimulus, such as a material that is thermally curable, curable upon exposure to ultraviolet light, curable upon exposure to mechanical pressure, or curable in response to another type of stimulus, or a combination of any two or more thereof.

[0190] To cure the attachment element, the bonding tool applies a stimulus to the attachment element, such as high temperature, ultraviolet light, mechanical pressure, or another stimulus, or a combination of any two or more thereof. The bonding tool can apply the stimulus through the discrete component (as shown in FIG. 14), through the device substrate, or both. In some examples, the bonding tool is the same tool that transfers the handle assembly onto the device substrate in a pick-and-place approach to component transfer. The stimulus is removed after a sufficient time to cure the attachment element, forming a mechanical bond, an electrical bond, or both, between the discrete component and the device substrate.

[0191] In some examples, the component interconnection process steps can include wire bonding. In some examples, the component interconnection process steps can include placing the discrete components in a face-up configuration on a device substrate and printing a conductive material onto the substrate and active surfaces of the discrete components.

[0192] [Remove Handle] In the handle removal process step, the handle substrate is detached and removed from the discrete components, leaving only the discrete components bonded to the device substrate. The handle substrate is attached to the discrete components via a handle release layer, which provides adhesion between the discrete components and the handle substrate, which can be released in response to an applied stimulus, such as temperature, ultraviolet light, normal or shear mechanical force, or another stimulus, or a combination of any two or more thereof.

[0193] To detach the handle substrate from the discrete components, the release tool applies a stimulus to the handle release layer, such as high temperature, ultraviolet light, normal or shear mechanical force, or another stimulus, or a combination of any two or more thereof. The release tool can apply the stimulus through the discrete components, through the device substrate, or through both. In some examples, the release tool is the same as the bonding tool that applies the stimulus to the attachment element. The stimulus is removed after a time sufficient to release the handle release layer. The handle substrate is removed, for example, by suction, forced air, the action of the release tool, or otherwise.

[0194] In some examples, the handle release layer and the attachment elements are responsive to the same stimulus. A single stimulus can be applied that simultaneously hardens the attachment elements and releases the handle release layer. For example, if the handle release layer and the attachment elements are responsive to the same stimulus, a single release tool can be used to harden the attachment elements, release the handle layer, and remove the handle. In some examples, the handle release layer and the attachment elements are responsive to different stimuli that are applied simultaneously or sequentially.

[0195] Some of the processes described herein do not use a handle substrate, and therefore do not perform a handle removal process step.

[0196] As mentioned above, these steps can be combined in various combinations to provide a variety of processes for placing discrete components on a device substrate. Five exemplary processes are summarized in Table 1 and each is described herein.

[0197] [Table 1]

[0198] [Handle-assisted ultra-small tip assembly] The handle-assisted microchip assembly process allows the assembly of small (in lateral dimensions) discrete components to be transferred using a pick-and-place approach. As shown in FIG. 16, the process 410 for packaging ultra-small and ultra-thin discrete components can generally include discrete component fabrication (412), wafer preparation (414-422), discrete component transfer (424-430), discrete component interconnection (430), and handle removal. The discrete component transfer in the process 410 includes discrete component transfer onto a handle substrate (424), dicing the handle substrate (426), mounting site preparation (428), and discrete component transfer onto a device substrate (430).

[0199] Generally, a wafer having a large number of discrete components can be fabricated 412 on a semiconductor material, such as a bulk silicon substrate or a layered silicon-insulator-silicon substrate, using known semiconductor techniques, such as thin-film methods.

[0200] Wafer preparation in process 410 may include partial dicing (404) of the wafer using known semiconductor techniques. For example, the discrete components may be partially separated by dry or wet etching, mechanical cutting (as shown in FIG. 16), or laser micromachining. The wafer surface may be protected from damage using a masking film and / or passivation layer. For example, photolithography or stencil / screen printing methods may be used to apply and pattern a layer of photoresist, polymer, UV curable polyimide, laminate film, or another suitable material.

[0201] The masking film can be formed according to known semiconductor techniques and materials, such as by applying a photoresist to the wafer. The thickness and composition of the masking film material is selected with consideration of anticipated downstream processing steps in wafer fabrication. For example, the thickness and composition of the masking film are selected such that after the streets are opened, the masking film is removed, for example, during an etching process (420) (described below).

[0202] The depth of the removed material in the wafer streets can be selected based on the expected attachment process and the desired final thickness of the assembled discrete components. For example, in a discrete component face-up process used to form the handle assembly 100 as shown in FIG. 2, the wafer street depth is less than the desired final discrete component thickness, and preferably greater than 1 μm and less than ½ the final discrete component thickness. The street width can be selected based on the dicing method, for example, in terms of the accuracy and precision of the dicing method.

[0203] Wafer preparation in process 410 includes forming thin wafers (416-418), such as thin wafers having thicknesses of 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, and 5 μm or less. The thickness of the wafer can be reduced or thinned based on the desired final discrete component dimensions by known semiconductor thinning techniques, such as mechanical grinding, chemical mechanical planarization (CMP), wet etching, atmospheric downstream plasma etching (ADP), dry chemical etching (DCE), vapor phase etching, or any combination thereof, such as mechanical grinding followed by chemical mechanical polishing.

[0204] In some instances, the wafer can be thinned to a thickness of about 50 μm using mechanical grinding techniques such as back grinding. However, generally, as the wafer thickness is reduced, the wafer becomes more susceptible to damage from mechanical grinding due to the fragility of the thin wafer. To reduce the risk of damaging the wafer, non-contact material removal processes can be used to reduce the wafer thickness beyond that achievable by conventional mechanical grinding processes. For example, to achieve a wafer thickness of 20 μm or less, thin wafers can be fabricated using known non-contact material removal processes such as reactive ion etching (RIE), vapor phase etching, or other suitable processes.

[0205] Before and during wafer thinning, the wafer can be attached to a temporary handling substrate (416-418). The temporary handling substrate releasably adheres to the wafer and is removable without damaging the wafer. For example, the temporary handling substrate can include a semiconductor tape, such as a thermal release tape (e.g., Nitto's ELEP Holder®, etc.) or an ultraviolet release tape, or can include a wafer handling fixture configured to releasably connect to the wafer using vacuum forces, electrostatic forces, or other means suitable for handling thin wafers. The thermal release tape or ultraviolet release tape is selected such that the tape adheres to the wafer but is removable by either application of heat or UV, respectively. In some cases, the temporary handling substrate can be a laser-transparent temporary handle (420-422), for example, a glass temporary handle using a dynamic release layer (referred to as DRL) as disclosed in WO 2012 / 033147, which is incorporated herein by reference in its entirety.

[0206] As described above, the discrete components are formed by separating portions of the semiconductor material from the wafer, for example along the streets formed in the wafer. As shown in FIG. 16, dry etching techniques can be used to release the individual discrete components from the wafer, for example RIE is used (420-422). As described above, parameters and plasma gas composition are selected such that the silicon in the streets is completely etched or removed (420) before etching or removing other masking materials (422). For example, if RIE is used, the photoresist material and thickness can be selected depending on the process parameters and plasma gas composition. In this case, the parameters and plasma gas composition are selected such that the silicon in the streets is completely etched or removed before etching or removing other masking materials. In some cases, the process parameters include a 1:1 mixture of SF6 and O2 as the plasma gas, a pressure of 13-14 Pa, a power of 135 W, and a DC bias of 150 V. In this example, after the streets are opened, etching continues until the masking layer is completely removed from the discrete component surface.

[0207] Component transfer in process 410, including releasing the individual discrete components from the handling substrate, will depend on the handling substrate material and / or adhesive material used. As described above, for example, the discrete components are attached to a glass temporary handle using a DRL layer. In this case, the discrete components can be released from the DRL using a laser transfer method without contacting the ultra-thin discrete components (424). Other methods capable of handling ultra-thin discrete components can be used to transfer the discrete components to the handle substrate.

[0208] In the example of Fig. 16, component transfer includes both laser transfer and pick-and-place. Discrete components are transferred from the DRL onto a handle substrate using laser transfer. The handle substrate provides a handle larger than the size compatible with the pick-and-place approach to component transfer, allowing the handle assembly to be transferred to the device substrate by a pick-and-place approach.

[0209] 16 and 17, the discrete components can be released from the DRL layer and attached to the handle substrate (424) by using a laser non-contact technique for ultra-thin chip assembly (referred to as tmSLADT) disclosed in WO 2012 / 142177, which is incorporated herein by reference in its entirety. The distance 508 between each discrete component 10 can be selected based on the capabilities of the wafer dicing tool, e.g., kerf and accuracy, the dimensions of the ultra-small and ultra-thin discrete components 10, and the dimensions of the handle 108. Suitable wafer dicing tools and / or methods include sawing, laser cutting, scribing, stealth dicing, and other known suitable methods. In some examples, the distance 502 is greater than 50 μm, e.g., between 50 μm and 200 μm. Prior to forming individual handle assemblies, e.g., handle assembly 100, one or more discrete components 10 are released onto oversized handle substrate 108a to form oversized handle assembly 510. In some cases, the oversized handle assembly is placed under a glass temporary handle from which the discrete components are released using a laser transfer method, so that when the discrete components are released from the glass temporary handle, each discrete component moves in a direction generally indicated by arrow 512 toward a handle release layer 105a previously coated on the handle substrate 108a using any suitable process, such as lamination or spin coating. The characteristics of the handle substrate 108a, the second surface 106a, and the handle release layer 105a, including the first surface 104a, are generally similar to those described with respect to the handle assembly 100, except for the larger size of the handle substrate 108a and the associated handle release layer 105a.

[0210] In some examples, the second surface 106a includes a pressure-activated adhesive for attaching the handle release layer 105a to the handle substrate 108a, and the first surface 104a includes a thermal or UV release surface, such as a thermal or UV release layer for attaching the discrete components 10 to the handle release layer 105a. Thus, when the discrete components contact the handle release layer 105a, the discrete components are releasably attached to the handle substrate 108a until, for example, heat or UV light is applied. In some examples, the handle release layer 105a is a single layer such that the first surface 104a and the second surface 106a are the same material, such as a thermal or UV release adhesive.

[0211] The component transfer in process 410 includes transferring the handle assembly 100 onto a device substrate. As described elsewhere, the methods described herein are used to attach ultra-thin and / or ultra-small bare discrete components to any device substrate used in integrated circuit packaging, such as printed circuit boards, plastic casings, ceramic substrates, flexible circuits, or other device substrates. Before attaching the discrete components to a device substrate, such as device substrate 614, a discrete component attachment means can be provided. For example, as shown in FIG. 18, a heat-cured non-conductive discrete component attachment material (such as Henkel's Ablebond 8008NC) can be dispensed to form an adhesive surface 618 for attaching the discrete components to device substrate 614 (418).

[0212] 16 and 18, the transfer 610 to the device substrate can include, for example, a discrete component bonding tool 612, a handle assembly 100, and a device substrate 614. In some implementations, the discrete component bonding tool 612 is attached to the handle substrate 108 of the handle substrate assembly 100. The discrete component bonding tool 612 moves toward the device substrate and places the discrete component 10 directly on the mounting surface 618 on the device substrate 614. The discrete component bonding tool 612 then moves the handle assembly 100 toward the device substrate, for example, in a direction generally indicated by arrow 620, until the discrete component 10 contacts the bonding surface 618. Once contact is made, the discrete component interconnection and handle removal occurs. The discrete component bonding tool applies a force and temperature profile that can cure the adhesive on the bonding surface 618. Because the discrete components 10 are attached to the handle substrate assembly via a thermal release layer, the temperature profile provided to the adhesive on the adhesive surface 618 quickly or simultaneously weakens the bond between the discrete components 10 from the handle substrate 108. The remaining bond strength between the handle substrate 108 and the discrete components 10 is insufficient to overcome the bond strength between the discrete components 10 and the device substrate 614. As a result, the discrete components 10 remain attached to the device surface as the discrete component bonding tool 612 and the handle substrate move away from the device substrate. The handle substrate can then be released from the discrete component bonding tool by applying positive pressure through the discrete component bonding tool and discarded elsewhere.

[0213] If the handle substrate includes a UV release layer (104) rather than a thermal release layer, the transfer means, e.g., the discrete component bonding tool 612, can be useful with a device capable of emitting UV light. Similar to a thermal release discrete component bonding tool, a UV release discrete component bonding tool can emit UV light with sufficient intensity to detach the discrete component from the handle. In this case, an additional heat source is needed to bond the discrete component to the device substrate. Such a heat source can be integrated into the worktable that holds the device substrate.

[0214] In a particular embodiment, the discrete components are bonded to the handle substrate by a UV releasable layer, and the adhesive on the device substrate can be a UV curable adhesive material, where emitting UV light of sufficient intensity based on the adhesive selected can weaken the bond between the discrete components and the handle substrate and bond the discrete components to the adhesive on the device substrate.

[0215] In some examples, various combinations of heat or UV sensitive adhesives are used to weaken the bond between the discrete components and the handle substrate and strengthen the bond between the discrete components and the device substrate.

[0216] Optionally, heat or UV light is also or alternatively applied through the device substrate to cure the adhesive on the device substrate.

[0217] In some embodiments, transferring the discrete components to the device substrate can include steps such as:

[0218] As shown in FIG. 19 , a process 720 for packaging ultra-small and / or ultra-thin discrete components in a face-up configuration generally includes the steps of obtaining or manufacturing a wafer (722), partially dicing the wafer (724), thinning the wafer (726), separating the discrete components from the wafer (728), transferring the discrete components from the wafer to a temporary handle substrate (730), transferring the discrete components from the temporary handle substrate to a handle substrate (732), bonding the discrete components to the handle substrate while weakening the bonds between the temporary handle substrate and the discrete components (732), dividing the handle substrate into a plurality of individual handle substrates, each of which includes a discrete component (734), and bonding the discrete components to the handle substrate (732). The method may include preparing a device substrate for mounting components (736); picking up the handle assembly with a discrete component bonding tool and positioning the handle assembly on the device substrate such that the discrete component aligns with the mounting adhesive on the device substrate (738); moving the discrete component into contact with the mounting adhesive on the device substrate (738); releasing energy (738) to weaken the bond between the discrete component and the handle substrate and strengthen the bond between the discrete component and the device substrate; moving the discrete component bonding tool away from the device substrate with the discrete component bonded to the device substrate (738); and releasing the handle substrate from the discrete component bonding tool (739).

[0219] Generally, a wafer having a large number of discrete components can be fabricated (722) on a semiconductor material, such as a bulk silicon substrate or a layered silicon-insulator-silicon substrate, using known semiconductor techniques, such as thin film processes.

[0220] During dicing (724), the wafer may undergo partial dicing using known semiconductor techniques. For example, the discrete components may be partially separated by dry or wet etching, mechanical grinding (as shown in FIG. 19), or laser cutting. In certain cases, the wafer is diced to create street depths equal to or slightly greater than the thickness of the final discrete components.

[0221] In some embodiments, the wafer thinning and discrete component separation is generally similar to the wafer thinning and discrete component separation described with reference to process 410, except for the discussion related to the masking film. For example, process 720 omits the masking film and simply performs a dry etch (728) until the streets are unobstructed.

[0222] The process of transferring the discrete components from the wafer (730) is generally similar to that described with reference to process 410, except that the discrete components are first transferred to the temporary substrate handle 818 along the direction 822, with each discrete component 10 separated by a distance 812. Referring to FIG. 20, the oversized handle assembly 810 is generally similar to the oversized handle assembly 510, except for the location of the active surface 102 of the discrete components and the type of handle release layer 815. Here, the active surface of the discrete components is oriented in a direction away from the temporary substrate 818. In addition, the temporary substrate 818 is covered with a low-temperature adhesive heat release tape, so that the tape loses its adhesiveness when exposed to a certain temperature. For example, REVALPHA 319Y-4L by Nitto® has a release temperature of 90° C.

[0223] With reference to FIG. 21, in order to transfer the discrete components from the temporary handle substrate 818 to the handle substrate 108, the temporary handle substrate 818 is placed or laminated on the handle substrate 108. In this case, the handle substrate 108 includes a handle release layer 105 that is heat sensitive and has a release temperature higher than that of the temporary handle substrate, for example a layer 104 such as REVALPHA 319Y-4H by Nitto® with a release temperature of 150° C. To weaken the bond between the discrete components and the temporary handle substrate, the laminate is heated to a temperature higher than the release temperature of the low-temperature tape but lower than the release temperature of the high-temperature tape. This condition results in the temporary handle substrate 818 losing adhesion. In this way, the temporary handle substrate is freely removable. In some cases, the temporary substrate assembly is also reusable.

[0224] Although heating is mentioned as a manner of causing the temporary handle substrate to lose its adhesive strength, a variety of techniques can be used for that purpose.

[0225] For example, mechanical techniques can be used. In those approaches, the handle release layer can lose adhesion by applying a stimulus that causes a change in the surface morphology of the handle release layer. In some embodiments, the stimulus can be heat or UV light, and the corresponding change in the surface morphology of the handle release layer can include the formation of small blisters on the surface. Such a change in surface morphology from smooth to blistered will cause a transition from an adhesive with sufficient adhesion to a very rough adhesive with very low adhesion. In some cases, the material used for the handle release layer can be selected to respond to such a stimulus by changing its surface morphology.

[0226] In some instances, the loss of adhesion is accomplished by a phase transition in which the handle release layer loses adhesion due to a physical change in state caused by the application of a stimulus. The phase transition can be from solid to liquid (e.g., melting) or from solid to gas (sublimation) or a combination thereof. The stimulus can be light, heat, pressure, or a combination of any two or more thereof.

[0227] In some examples, the loss of adhesion can be caused by a chemical process. For example, chemically induced loss of adhesion can be based on a change in the chemical structure or composition of the handle release layer or its components. In some cases, the handle release layer or its components can be those that change their chemical structure when exposed to a stimulus. In some examples, the materials can be materials that change their chemical composition (e.g., decompose) when a stimulus is applied. Such materials can include materials that undergo i) thermal decomposition, or thermolysis, which is chemical decomposition caused by heat, and ii) photolysis, which is decomposition caused by the absorption of light. The stimulus for the chemical process can be light or heat or both.

[0228] Thus, in some examples, the release mechanism does not involve melting of the handle release layer material. Releasing the handle layer without melting allows the handle substrate to be removed by a vertical motion rather than a lateral sliding motion. Removing the handle substrate vertically may be advantageous, for example, when the handle substrate is removed by a conventional die bonder. Removing the handle substrate by a lateral sliding motion may be advantageous in environments such as roll-to-roll assembly lines where the handle substrate forms part of a continuous web. Releasing the handle release layer material without melting may help to prevent residues from remaining on the surface of the discrete components after the handle is removed.

[0229] In some embodiments, the handle release layer or the process that reduces its adhesion, or both, can be selected so that the loss of adhesion is permanent or that recovery of adhesion is prevented, inhibited, or delayed. This approach has the advantage of reducing or eliminating the time constraints on when the handle must be removed. For example, such materials may undergo recovery of adhesion within about 10 seconds, 30 seconds, 1 minute, 5 minutes, 10 minutes, or another time after the loss of adhesion. For example, if the wax is melted to reduce the adhesion of the handle release layer, the wax will resolidify relatively quickly, so there will be little time to remove the handle after the heat that caused the wax to melt has subsided. Imposing a requirement that the handle must be removed quickly before the handle release layer material solidifies places undesirable constraints on the manufacturing process. Exemplary materials for which the loss of adhesion is permanent or recovery of adhesion is prevented, inhibited, or delayed include materials that degrade, decompose, or sublime; or adhesive tapes, such as REVALPHA® double-sided heat release tape by Nitto®.

[0230] In some cases, the material of the handle release layer or the process for releasing it, or both, can be selected so that it does not leave a residue on the discrete components after release. For example, materials that do not leave a residue on the discrete components after release can include materials that change surface morphology (such as, for example, REVALPHA® double-sided thermal release tape by Nitto®) or materials that sublimate.

[0231] The discrete component packaging process, including providing a device substrate (736) and transferring the discrete components to the device substrate (738), is generally similar to the discrete component packaging process described with respect to FIG.

[0232] As shown in FIG. 22 , a process 1000 for packaging ultra-small and ultra-thin discrete components in a flip chip configuration generally includes the steps of obtaining or manufacturing a wafer (1002), partially dicing the wafer (1004), thinning the wafer (1006), separating the discrete components from the wafer (1008), transferring the discrete components to a handle substrate (1010), dividing the handle substrate into a plurality of individual handle substrates, each of which includes a discrete component (1012), preparing a device substrate for attachment of the discrete components (1014), and using a discrete component bonding tool. and placing the handle assembly on the device substrate such that the discrete components are aligned with the mounting adhesive on the device substrate (1016); moving the discrete components into contact with the mounting adhesive on the device substrate (1016); releasing energy to weaken the bond between the discrete components and the handle substrate and to strengthen the bond between the discrete components and the device substrate (1016); moving the discrete component bonding tool away from the device substrate with the discrete components bonded to the device substrate; and releasing the handle substrate from the discrete component bonding tool (1016).

[0233] Generally, wafers with bumped out discrete components as required in flip chip configurations are commonly known. Common methods for wafer bumping include stud bumping, electroless nickel-gold plating, solder balls, solder paste printing, solder electroplating, etc. Although an initial wafer with low profile electroless nickel-gold plating is compatible with the process described herein, bump creation may occur after the step of transferring the discrete components from the glass substrate (1010) and before the step of placing the discrete components on the handle substrate (1012).

[0234] The wafer dicing process (1004), wafer thinning process (1006), discrete component separation (1008), discrete component transfer (1010), individual handle substrate formation steps (1012), and discrete component bonding steps (1016) are generally similar to the other methods described above. For example, the discrete components 10 are similarly positioned on the handle substrate 108, except for the orientation of the active surfaces 102 on the discrete components 10, as shown in Figures 17 and 23. Here, each of the discrete components 10 is separated by a distance 1202 and moves along a direction 1204.

[0235] 22-23, the discrete component 10 is attached to the device substrate 618 using a conductive material 1106 and an adhesive material 1108.

[0236] The type of adhesive material and the method of application will depend on the method selected to electrically connect the discrete components to the conductor traces on the device substrate. For example, liquid conductive adhesives (e.g., anisotropic conductive adhesives, ACP, e.g., type 115-29 by Creative Materials, Inc.) or other commonly used methods and materials, such as anisotropic conductive films and pastes, isotropic conductive films and pastes, and solders, can be used. The discrete component bonding steps generally include the steps of picking up the handle assembly with a discrete component bonding tool and placing the handle assembly on the device substrate such that the discrete component aligns with the mounting adhesive on the device substrate (1016), moving the discrete component into contact with the mounting adhesive on the device substrate (1016), releasing energy to weaken the bond between the discrete component and the handle substrate and strengthen the bond between the discrete component and the device substrate (1016), moving the discrete component bonding tool away from the device substrate with the discrete component bonded to the device substrate, and releasing the handle substrate from the discrete component bonding tool (1016).

[0237] In certain embodiments, when an adhesion method beyond ACP bonding is used, it may be desirable to customize 1014 the site preparation features and / or processes to accommodate the new material.

[0238] [Handle-assisted packaging process] As shown in Figure 25, the handle-assisted packaging process 1300 allows for packaging ultra-thin discrete components in a flip-chip configuration with a handle substrate. A wafer having a large number of discrete components is obtained or manufactured (1302).

[0239] Wafer preparation in process 1300 includes wafer thinning, handle attachment, and dicing. The wafer is thinned to a thickness of less than 50 μm, for example, about 25 μm thick. For example, the wafer can be thinned using a mechanical thinning process or a mechanical thinning process followed by a non-contact thinning process (1304). The ultra-thin wafer is attached to a handle substrate (1306). In the example of FIG. 25, the backside of the wafer is bonded to a 350 μm thick handle substrate via a 20 μm thick handle release layer, leaving the active layer of the wafer exposed. In some examples, the active layer of the wafer can be bonded to the handle substrate, leaving the backside of the wafer exposed.

[0240] The wafer and handle substrate assembly is attached to a dicing tape and diced into individual discrete components. For example, the wafer and handle substrate assembly can be diced by mechanical sawing (1308) followed by laser stealth dicing (1309) or both to form discrete components attached to the diced portion of the handle substrate. The discrete components on the diced portion of the handle substrate may be referred to as the handle assembly.

[0241] In general, wafer formation (1302) and wafer thinning by contact or non-contact material removal processes (1304) are generally similar to processes described elsewhere. However, singulation of individual discrete components and sizing of the handle substrate (1308, 1309) may be somewhat streamlined in some cases. For example, referring to FIG. 26, a handle release layer 305 including a second side 306 and a first side 304 is applied (1306) along with a heat or UV release layer exposed on the backside of the ultra-thin wafer and a pressure sensitive layer attached to the handle substrate. In this case, the length and width of the handle substrate 308 may be equal to the dimensions of the ultra-thin discrete components 30. In this manner, the handle substrate and wafer may be diced (1308) into individual handle assemblies 300 simultaneously.

[0242] Component transfer in process 1300 includes preparing a device substrate for discrete component attachment (1310) and transferring a handle assembly onto the prepared device substrate using a pick-and-place approach (1312). With reference to Figure 26, in the pick-and-place approach, the handle assembly 300 is picked up using a discrete component bonding tool 612 and placed onto the device substrate 614 such that the discrete components 30 mate with the attachment adhesive 618 on the device substrate 614. The discrete components are moved into contact with the attachment adhesive 618 on the device substrate 614.

[0243] Component interconnection and handle removal in process 1300 includes discharging 1312 energy to weaken the bond between the discrete component 30 and the handle substrate 618 and strengthen the bond between the discrete component 30 and the device substrate 614. With the discrete component 30 bonded to the device substrate 614, the discrete component bonding tool 612 is moved away from the device substrate 614. The handle substrate 618 is released 1312 from the discrete component bonding tool 612.

[0244] As with other flip-chip configurations, the discrete components are attached to the device substrate 618 using conductive material 1106.

[0245] [Laser-compatible packaging process] 27, a laser-enabled packaging process 150 allows for packaging of ultra-thin, ultra-small discrete components without the use of a handle substrate. A wafer having a large number of discrete components is manufactured or obtained (152).

[0246] Wafer processing in process 150 can optionally include wafer thinning (not shown). The wafer (which may be thinned) is attached to a dicing tape and diced 154 into individual discrete components using approaches such as those described above. In some examples, process 150 is performed during the wafer thinning step.

[0247] Wafer transfer (155) in process 150 can include transferring the diced discrete components from a dicing tape to a transparent carrier, such as a glass carrier, for example, by vacuum assisted transfer. This transfer allows process 150 to be used for flip chip assembly. Other approaches to dicing and wafer transfer can also be used in process 150.

[0248] Component transfer in process 150 involves releasing (156) the discrete components from the transparent carrier using the laser-assisted non-contact transfer methods described above. The discrete components are transferred onto the device substrate having mounting elements formed thereon. Discrete component interconnects (158) are made by application of pressure, temperature, or ultraviolet light, as described above. Because process 150 does not use a handle substrate, no handle removal is required.

[0249] Process 150 can have advantages. For example, using a laser-assisted non-contact transfer method to transfer components allows the process to be adapted to transfer a wide range of component sizes and types, including components that are too small for a pick-and-place approach or that are not suitable for mounting on a handle substrate. Process 150 can operate at higher throughput than other non-laser-assisted processes because the laser can be electronically scanned to rapidly transfer successive discrete components with little or no realignment of the transparent carrier.

[0250] [Direct laser compatible packaging process] Referring to Figure 28, a laser-enabled packaging process (160) allows for packaging of very small discrete components without the use of a handle substrate. A wafer having a large number of discrete components is manufactured or obtained (162).

[0251] Wafer processing in process 160 can optionally include wafer thinning (not shown). The wafer (which may be thinned) is bonded to a transparent carrier, such as a glass carrier, having a dynamic release layer disposed thereon, and diced into individual discrete components while attached to the transparent carrier (166) using approaches such as those described above. Although the wafer is shown bonded to a UV release adhesive material on the transparent carrier, the wafer can also be bonded to the dynamic release layer without a UV release material.

[0252] The wafer and handle substrate assembly is directly attached to a transparent carrier for dicing, rather than to a dicing tape, allowing the wafer transfer process to be bypassed. Other approaches to wafer transfer and dicing can also be used in process 160.

[0253] Component transfer in process 160 involves releasing (168) the discrete components from the transparent carrier using the laser-assisted non-contact transfer methods described above. The discrete components are transferred onto the device substrate having mounting elements formed thereon. Discrete component interconnects (170) are made by application of pressure, temperature, or ultraviolet light, as described above. Because process 160 does not use a handle substrate, no handle removal is required.

[0254] In process 160, part transfer is performed using a laser-assisted non-contact transfer method, making the process adaptable to transfer a wide range of part sizes and types, including parts that are too small for a pick-and-place approach or not suitable for mounting on a handle substrate.

[0255] Process 160 can have advantages. For example, process 160 has a simplified process flow compared to other laser-assisted processes by eliminating the diced wafer transfer step. Process yield can be improved because there is no chance of die loss during the transfer of diced discrete components. Additionally, because the wafer is transferred as an intact unit, the possibility of die shifting or rotating relative to their original position on the wafer during the transfer of diced discrete components is eliminated.

[0256] [Laser-enabled handle-assisted packaging process] 29, a laser-enabled handle-assisted packaging process 180 enables packaging of ultra-thin discrete components with a handle substrate. A wafer having a large number of discrete components is manufactured or obtained (182).

[0257] Wafer preparation in process 180 includes wafer thinning, handle attachment, and dicing. The wafer is thinned (184) to a thickness of less than 50 μm using one or more of the wafer thinning approaches described above. In the example of FIG. 29, the wafer is thinned to a thickness of about 25 μm using a combination of backgrinding, dry etching, or chemical mechanical polishing, and using a support substrate. A handle substrate is attached (186) to the thinned wafer. In the example of FIG. 29, the backside of the wafer is bonded to a 350 μm thick handle substrate via a 20 μm thick handle release layer, leaving the active layer of the wafer exposed. In some examples, the active layer of the wafer can be bonded to the handle substrate, leaving the backside of the wafer exposed. The wafer and handle substrate assembly is attached to a dicing tape and diced into individual discrete components. For example, the wafer and handle substrate assembly can be diced directly by mechanical cutting (188) and indirectly by laser micromachining (sometimes referred to as laser stealth dicing) (190) to form discrete components attached to the diced portions of the handle substrate (collectively referred to as the handle assembly). Other approaches to dicing the wafer and handle substrate assembly as described above can also be used.

[0258] Wafer transfer in process 180 includes a step (192) of transferring the handle assembly from the dicing tape to a transparent carrier, such as a glass carrier. The handle assembly adhered to the dicing tape is removed from the dicing tape, for example by suction provided from a vacuum chuck. A transparent carrier, such as a glass carrier having a dynamic release layer disposed thereon, is brought into contact with the handle assembly sucked onto the vacuum chuck, resulting in transfer of the handle assembly to the carrier. The suction force is removed and the vacuum chuck is removed. Other approaches to dicing and wafer transfer can also be used in process 180.

[0259] Component transfer in process 180 includes releasing the handle assembly from the transparent carrier (194), for example using the laser-assisted non-contact transfer methods described above. The handle assembly is transferred onto the device substrate having the mounting elements formed thereon. Discrete component interconnects (196) and handle removal (198) are accomplished by application of pressure, temperature, or ultraviolet light, as described above.

[0260] In process 180, part transfer is performed using a laser-assisted non-contact transfer method, making the process adaptable to transfer a wide range of part sizes and types, including parts that are too small or thin for a pick-and-place approach.

[0261] In process 180, a laser-assisted non-contact transfer method is used to transfer the handle assembly rather than just the discrete components. Because the mass of the item being transferred correlates to the accuracy of transfer in a laser-assisted non-contact transfer method, transferring the handle assembly rather than just the discrete components allows for more accurate placement of the handle assembly on the device substrate.

[0262] In process 180, the discrete component interconnections are made while the discrete components are still attached to the associated portions of the handle substrate. A thick assembly of discrete components and handle substrate is less susceptible to cracking during curing of the mounting elements on the device substrate during discrete component interconnections (e.g., during curing of the conductive epoxy) than a discrete component that is not attached to the handle substrate.

[0263] Process 180 can have advantages, such as improving the accuracy of part transfer, and can be used to transfer ultra-thin chips that may be difficult to manipulate otherwise.

[0264] [Direct laser-compatible handle-assisted packaging process] 30, a laser-enabled handle-assisted packaging process 250 enables packaging of ultra-thin discrete components. A wafer having a large number of discrete components is manufactured or obtained (252).

[0265] Wafer preparation in process 250 includes wafer thinning, handle attachment, and dicing. The wafer is thinned (254) to a thickness of less than 50 μm using one or more of the wafer thinning approaches described above. In the example of FIG. 30, the wafer is thinned to a thickness of about 25 μm using a combination of backgrinding, dry etching, or chemical mechanical polishing, and using a 3M Wafer Support System®. The thinned wafer is attached (256) onto a handle substrate to form a handle assembly. In the example of FIG. 30, the backside of the wafer is bonded to a 350 μm thick handle substrate via a 20 μm thick handle release layer, leaving the active layer of the wafer exposed. In some examples, the active layer of the wafer can be bonded to the handle substrate, leaving the backside of the wafer exposed.

[0266] In some examples, the wafer is partially pre-diced (258) while attached to a dicing tape, and then transferred (260) to a transparent carrier for full dicing (262). In some examples, the wafer and handle substrate assembly is bonded (258) to a transparent carrier, such as a glass carrier having a dynamic release layer disposed thereon, and diced (259) into individual discrete components using approaches such as those described above. Because the wafer and handle substrate assembly is bonded directly to a transparent carrier for dicing, rather than to a dicing tape, the wafer transfer process can be bypassed. Other approaches to dicing and wafer transfer can also be applied to the process 250.

[0267] Component transfer in process 250 involves releasing (264) the discrete components from the transparent carrier using the laser-assisted non-contact transfer methods described above. The discrete components are transferred onto a device substrate having mounting elements formed thereon. Discrete component interconnects (266) and handle removal (268) are accomplished by application of pressure, temperature, or ultraviolet light, as described above.

[0268] Process 250 uses a laser-assisted non-contact transfer method to perform part transfer, making the process adaptable to transfer a wide range of part sizes and types, including parts that are too thin for a pick-and-place approach.

[0269] Process 250 can have advantages. For example, process 250 has a simplified process flow compared to other laser-assisted processes by eliminating the diced wafer transfer step. Process yield can be improved because there is no chance of die loss during the transfer of diced discrete components. Additionally, because the wafer is transferred as an intact unit, the possibility of die shifting or rotating relative to their original position on the wafer during the transfer of diced discrete components is eliminated.

[0270] 31, the process for packaging discrete components described above can be modified as shown in process 1500 for attaching a discrete component 1501 to a device substrate 1502. For example, first prepare 1310 the device substrate 1502 for attachment to the discrete component 1501 by dispensing a quantity of adhesive 1505 onto a device substrate surface 1509 (including conductors 1511) via a dispensing conduit 1507 at a location 1515 on the device substrate 1502 where the discrete component will be attached.

[0271] Next, the process 1500 may generally include picking up (1502) the handle assembly 1552 (including the discrete components 1501, the handle substrate 108, and the handle release layer 105) by applying 1513 a vacuum via a vacuum tube 1516 of the discrete component transfer tool 1508. The transfer tool with the handle assembly is then positioned (1502) over a location 1515 of the device substrate, as also shown in Figures 25 and 26, to align the discrete components with the mounting adhesive on the device substrate 1502 (614 in Figure 18). The discrete components are then moved into contact with the mounting adhesive 1505 (618 in Figure 18) on the device substrate 1502.

[0272] After the discrete components are contacted with the (may or may not be in some fluid state at the moment) attachment adhesive 1505 (618 in FIG. 18) on the device substrate 1502, the vacuum in the vacuum tube can be broken to release the transfer tool 1508 from the handle and the transfer tool can be moved away. A separate discrete component bonding tool 1510 can then be moved in and brought into contact with the discrete components. Pressure 1550, or energy 1551, e.g. heat or UV energy, or both can then be applied 1517 via the contact surface 1519 of the bonding tool 1510 to the discrete components 1501, the handle substrate 108, the handle release layer 105, via the handle to the bond 1521, via the bond to the discrete components 1501, and via the discrete components 1501 to the bond 1523 with the device substrate 1502. Pressure or energy or both can simultaneously or sequentially weaken the bond 1522 between the discrete component and the handle substrate and strengthen the bond 1523 between the discrete component and the handle substrate (1504). When pressure is applied, it can operate to simultaneously weaken bond 1522 and strengthen bond 1523. When energy is applied, the energy must flow through successive components of the system such that, in some cases, weakening of bond 1522 begins or is completed before strengthening of bond 1523 begins or is completed, or weakening and strengthening can occur sequentially.

[0273] In some cases, the handle release layer 105 and the attachment adhesive are selected such that the bond 1523 between the discrete components 1501 and the device substrate 1502 is formed before the bond 1521 is formed between the handle and the discrete components 1501, or the formation of the bond 1523 and the bond 1521 can occur simultaneously, completely overlapping in time, or its formation can partially overlap either the bond 1523 or the bond 1521, occurring before or after the partial overlap. The formation of either the bond 1523 or the bond 1521 can include hardening or softening of a material, such as a wax material. For example, in some cases, the handle release layer 105, the attachment adhesive 1505, or both the handle release layer 105 and the attachment adhesive 1505 may include one or more materials that soften or harden in response to the application of energy. In this case, the softening of bond 1523 may occur before the hardening of bond 1521, or the softening of bond 1521 may occur after the hardening of bond 1521, or the two events may completely overlap in time and occur simultaneously, or they may overlap but one or the other may occur partially before or after the time of the overlap.

[0274] Once the weakening and strengthening has progressed to an appropriate degree, the discrete component bonding tool 1510 can be removed with the handle assembly (including the discrete components 1501, handle substrate 108, handle release layer 105) in contact with the discrete components bonded to the device substrate 1502. Although no longer bonded to the discrete components (due to the weakening of the bond 1523), the handle remains in contact with the discrete components due to, for example, gravity, surface attraction, or residual adhesive forces remaining after the bonding process, or a combination of two or more of these forces. The handle substrate can then be removed 1506 from the discrete components using any of a variety of separation techniques, such as, for example, brushing, compressed air, vacuum, vibration, liquid jets, electrostatic forces, electromagnetic forces that reorient the device substrate such that gravity separates the handle from the discrete components, or any combination of two or more thereof. In general, various separation techniques are envisaged to separate the handle substrate from the discrete components, such as applying force, energy, contact, and any combination of two or more of these, so long as the discrete components and / or the handle substrate are not damaged.

[0275] In some examples, the discrete component transfer tool 1508 can be configured to apply a vacuum force to the handle assembly, similar to the use of the discrete component transfer tool 612 in FIG. 18. In some examples, the discrete component transfer tool 1508 can be configured to apply pressure, heat, or UV light, or a combination thereof, to the handle assembly, similar to the use of the discrete component transfer tool 602 in FIG.

[0276] 31 illustrates the removal of one handle assembly, the same separation technique or techniques can be used to remove two or more handle assemblies simultaneously. For example, multiple handle substrates may be positioned in close proximity to one another such that a brush, a blade, application of compressed air, application of a vacuum, or application of a vibratory force, or any combination of two or more thereof, may remove two or more handle assemblies from their corresponding discrete components.

[0277] In some examples, starting with individual discrete components having a regular thickness rather than starting with a wafer, one or more of the processes described herein can be used to place thin discrete components on a device substrate. Using a process starting with individual discrete components, multiple different discrete components can be placed on a single device substrate. A pick-and-place approach or a laser-assisted non-contact transfer method can be used to place individual discrete components at target locations on the device substrate. In some examples, the device substrate can remain stationary and each discrete component can be moved relative to the device substrate until it reaches its target location. In some examples, the device substrate can be moved relative to the discrete components until the target location for a particular discrete component is located under that discrete component. The ability to place multiple different discrete components on a single substrate can have applications in research and development, for example, to facilitate testing of multiple types of discrete components.

[0278] 32, in process 450, individual discrete components 452 are received and mounted (440) onto a first handle substrate 454 via a handle release layer 456. The discrete components 452 can be mounted onto the first handle substrate 454 by a pick-and-place approach or another method for placing discrete components. The discrete components can be of various sizes and thicknesses compatible with a pick-and-place approach.

[0279] A second handle substrate 456 having a handle release layer 458 and a layer of flowable material 460 disposed thereon is brought into contact with the discrete components 452 on the first handle substrate 454 (441). The term "flowable material" is used broadly to include any material having a viscosity that allows the flowable material to flow in response to a stimulus, such as, for example, pressure and vacuum lamination applied when the second handle substrate 456 contacts the discrete components 452 on the first handle substrate 456. Exemplary flowable materials can include materials that undergo a phase change from liquid to solid in response to application of a stimulus, such as heat or light (e.g., ultraviolet light). For example, the flowable material can include a positive photoresist (e.g., AZ® 40XT by AZ Electronic Materials, Merck, Darmstadt, Germany), a negative photoresist (e.g., SU-8 by MicroChem Corp, Newton, MA), a heat curable thermosetting polyimide, or other materials. A stimulus is applied to harden the flowable material (442), solidifying the flowable material around the discrete components 452. In some examples, the flowable material 460 is a photoresist, the second handle substrate 456 is a transparent substrate (e.g., glass or clear plastic), and the stimulus is light or heat sufficient to harden the photoresist. The second handle substrate 456 is removed (443), the discrete components 452 are thinned to a desired thickness (444), and the hardened flowable material 460 is removed (445) by wet or dry etching, for example using one or more of the approaches described above.

[0280] The thinned discrete components 452 are mounted (446) on a third handle substrate 462 that is covered with a handle release layer 464. The handle release layer 456 on the first handle substrate 454 is released (447) thereby detaching the discrete components from the first handle substrate 454. After cleaning, the discrete components 452 on the third handle substrate 462 can then enter any of the handle assisted processes (448) described above in the wafer transfer process steps.

[0281] The process 450 can be used when the discrete components 452 are attached face-down to the first handle substrate 454. In the case of face-up assembly, steps 447 and 447 are omitted and the first handle wafer 454 serves as the handle wafer for subsequent handle-assisted discrete component assembly as described above.

[0282] In some examples, one or more of the processes described herein can be used to fabricate three-dimensional integrated circuits (sometimes called stacked chips). Stacked chips are manufactured by stacking and vertically connecting discrete components, such as integrated circuits, such that the stacked discrete components behave together as a single device. Stacked chips can help increase current density and therefore improve computing power or memory. [Additional note 1] dicing the wafer to form discrete components; transferring the discrete components onto a transparent carrier, the step including adhering the discrete components to a carrier release layer on the transparent carrier; releasing one of the discrete components from the transparent carrier, the one of the discrete components being deposited on a device substrate after release; The method includes: [Additional note 2] 2. The method of claim 1, comprising thinning the wafer to a thickness of less than 50 μm. [Additional note 3] 3. The method of claim 2, wherein dicing the wafer includes dicing the thinned wafer to form the discrete components. [Additional note 4] dicing the wafer includes adhering the wafer to a dicing carrier; 4. The method according to any one of claims 1 to 3, wherein the step of transferring the discrete components onto the transparent carrier includes a step of transferring the discrete components from the dicing carrier to the transparent carrier. [Additional note 5] 5. The method of claim 4, wherein the dicing carrier comprises a dicing tape. [Additional note 6] 6. The method of any one of claims 1 to 5, wherein the step of releasing one of the discrete components from the transparent carrier includes the step of applying a stimulus to the carrier release layer on the transparent carrier. [Additional note 7] The method of claim 6, wherein the stimulus comprises ultraviolet (UV) light. [Additional note 8] 8. The method of any one of claims 1 to 7, wherein the transparent carrier is at least partially transparent to UV light. [Additional note 9] 9. The method of any one of claims 1 to 8, wherein the carrier release layer comprises a dynamic release layer (DRL). [Additional Note 10] 10. The method of any one of claims 1 to 9, wherein depositing one of the discrete components on the device substrate comprises depositing one of the discrete components on a mounting element disposed on a surface of the device substrate. [Additional Note 11] 11. The method of claim 10, wherein the mounting element comprises a thermosetting material. [Additional Note 12] 12. The method of claim 10 or 11, wherein the attachment element comprises a UV-curable material. [Additional Note 13] 13. The method of any one of claims 10 to 12, wherein the mounting element comprises a conductive material. [Additional Note 14] 14. The method of any one of claims 10 to 13, comprising applying a stimulus to harden the attachment element. [Additional Note 15] 15. The method of claim 14, wherein the discrete components are electrically connected to the device substrate by applying a stimulus to harden the mounting element. [Additional Note 16] 16. The method of any one of claims 1 to 15, further comprising bonding the discrete components to the device substrate. [Additional Note 17] 17. The method of any one of claims 1 to 16, comprising attaching the wafer to a handle substrate to form a wafer handle assembly. [Additional Note 18] 20. The method of claim 17, wherein the step of attaching the wafer to the handle substrate includes a step of attaching the wafer to a handle release layer formed on a surface of the handle substrate. [Additional Note 19] 20. The method of claim 18, wherein the handle release layer comprises a heat sensitive material. [Additional Note 20] 20. The method of claim 18 or 19, wherein the handle release layer comprises an ultraviolet (UV) sensitive material. [Additional Note 21] 21. The method of any one of claims 17 to 20, wherein dicing the wafer into discrete components comprises dicing the wafer handle assembly into handle assemblies, each handle assembly including a discrete component attached to a corresponding portion of the handle substrate. [Additional Note 22] transferring the discrete components onto the transparent carrier includes transferring the handle assembly onto the transparent carrier; 22. The method of claim 21, wherein depositing one of the discrete components on the device substrate includes depositing one of the handle assemblies on the transparent carrier. [Additional Note 23] 23. The method of claim 22, comprising releasing a corresponding portion of the handle substrate from the discrete components deposited on the device substrate. [Additional note 24] 24. The method of claim 23, comprising simultaneously releasing the corresponding portion of the handle substrate from the discrete components deposited on the device substrate and bonding the discrete components to the device substrate. [Additional note 25] 25. The method of claim 23 or 24, comprising applying a stimulus that causes (i) bonding of the discrete components to the device substrate and (ii) release of the handle substrate from the discrete components. [Additional note 26] 26. The method of any one of claims 23 to 25, comprising applying a first stimulus that causes bonding of the discrete components to the device substrate and a second stimulus that causes release of the handle substrate from the discrete components. [Additional note 27] 27. The method of any one of claims 17 to 26, comprising thinning the wafer to a thickness of less than 50 μm. [Additional note 28] 28. The method of claim 27, comprising attaching the thinned wafer to the handle substrate to form the wafer handle assembly. [Additional note 29] 29. The method of any one of claims 1 to 28, wherein each discrete component is ultra-thin, ultra-miniature, or both ultra-thin and ultra-miniature. [Additional note 30] 30. The method of claim 29, wherein each discrete component has a thickness of 50 μm or less. [Additional note 31] 31. The method of claim 29 or 30, wherein each discrete component has a maximum length of 300 μm / side or less. [Additional note 32] A method comprising the steps of releasing a handle assembly from a transparent carrier, the handle assembly being deposited on a device substrate after release, the handle assembly including discrete components releasably attached to a handle substrate, the discrete components being ultra-thin, ultra-miniature, or both ultra-thin and ultra-miniature. [Additional note 33] 33. The method of claim 32, wherein the handle substrate has a thickness of at least 50 μm. [Additional note 34] 34. The method of claim 32 or 33, comprising attaching the handle assembly to the transparent carrier. [Additional note 35] 35. The method of claim 34, wherein attaching the handle assembly to the transparent carrier includes transferring the handle assembly from a dicing carrier to the transparent carrier. [Additional note 36] 36. The method of any one of claims 32 to 35, comprising the step of attaching a wafer to a handle substrate to form a wafer handle assembly, the discrete components being formed on the wafer. [Additional note 37] 37. The method of claim 36, wherein the step of attaching the wafer to a handle substrate includes the step of attaching the wafer to a handle release layer formed on a surface of the handle substrate. [Additional note 38] 38. The method of claim 37, wherein the handle release layer comprises a heat sensitive material. [Additional note 39] 39. The method of claim 37 or 38, wherein the handle release layer comprises a UV-sensitive material. [Additional note 40] 40. The method of any one of claims 36 to 39, further comprising dicing the wafer-handle assembly to form a handle assembly. [Additional note 41] 41. The method of claim 40, comprising attaching the handle assembly to the transparent carrier. [Additional note 42] 42. The method of any one of claims 36 to 41, comprising thinning the wafer to a thickness of less than 50 μm. [Additional note 43] 43. The method of claim 42, comprising attaching the thinned wafer to a handle substrate to form a wafer handle substrate. [Additional note 44] 37. The method of claim 36, comprising attaching the wafer handle assembly to the transparent carrier. [Additional note 45] 45. The method of claim 44, further comprising dicing the wafer handle assembly attached to the transparent carrier into a handle assembly. [Additional note 46] partially dicing the wafer-handle assembly, the dicing comprising dicing less than a full thickness of the wafer-handle assembly; 46. ​​The method of claim 44 or 45, wherein attaching the wafer handle assembly to the transparent carrier comprises attaching the partially diced wafer handle assembly to the transparent carrier. [Additional note 47] 47. The method of claim 46, comprising dicing the partially diced wafer handle assembly attached to the transparent carrier into a handle assembly. [Additional note 48] 48. The method of any one of claims 44 to 47, comprising thinning the wafer to a thickness of less than 50 μm. [Additional note 49] 49. The method of claim 48, comprising attaching the thinned wafer to the handle substrate to form the wafer handle assembly. [Additional Note 50] 50. The method of any one of claims 44 to 49, comprising thinning the attached wafer to a thickness of less than 50 μm. [Additional note 51] 51. The method of any one of clauses 32 to 50, wherein the transparent carrier is at least partially transparent to ultraviolet light. [Additional note 52] 52. The method of claim 51, wherein the transparent carrier comprises glass. [Additional note 53] 53. The method of any one of claims 32 to 52, wherein releasing the handle assembly from the transparent carrier comprises applying a stimulus to a dynamic release layer disposed between a carrier substrate and the handle assembly. [Additional note 54] 54. The method of claim 53, wherein the stimulus comprises ultraviolet light. [Additional note 55] 55. The method of claim 53 or 54, wherein applying a stimulus to the dynamic release layer causes the dynamic release layer to mechanically release the handle assembly from the transparent carrier. [Additional note 56] 56. The method of any one of claims 32 to 55, wherein depositing the handle assembly on the device substrate comprises depositing the handle assembly on a mounting element disposed on the device substrate. [Additional note 57] 57. The method of claim 56, wherein the mounting element comprises a thermosetting material. [Additional note 58] 58. The method of claim 56 or 57, wherein the attachment element comprises a UV curable material. [Additional note 59] 59. The method of any one of clauses 56 to 58, wherein the mounting element comprises a conductive material. [Additional note 60] 60. The method of any one of claims 55 to 59, comprising applying a stimulus to harden the attachment element. [Additional note 61] 61. The method of any one of claims 32 to 60, further comprising bonding the discrete components to the device substrate. [Additional note 62] 62. The method of claim 61, further comprising releasing the handle substrate from the discrete components after depositing the handle assembly on the device substrate. [Additional note 63] 63. The method of claim 62, wherein the step of releasing the handle substrate from the discrete components comprises applying a stimulus to release a handle release layer disposed between the handle substrate and the discrete components. [Additional note 64] 64. The method of claim 62 or 63, comprising simultaneously bonding a wafer handle assembly to the device substrate and releasing the handle substrate from the discrete components. [Additional note 65] 65. The method of claim 64, comprising applying a stimulus that causes (i) bonding of the discrete components to the device substrate and (ii) release of the handle substrate from the discrete components. [Additional note 66] 66. The method of any one of claims 62 to 65, comprising applying a first stimulus that causes bonding of the discrete components to the device substrate and a second stimulus that causes release of the handle substrate from the discrete components. [Additional note 67] An apparatus comprising: a handle assembly mounted on a transparent carrier, the handle assembly comprising discrete components releasably mounted to a handle substrate, the discrete components being ultra-thin, ultra-miniature, or both ultra-thin and ultra-miniature. [Additional note 68] 68. The apparatus of claim 67, comprising a plurality of handle assemblies attached to the transparent carrier. [Additional note 69] 69. The device of claim 67 or 68, wherein the handle substrate has a thickness of at least 50 μm. [Additional note 70] 70. The device of any one of claims 67 to 69, wherein the transparent carrier is at least partially transparent to ultraviolet light. [Additional note 71] 71. The apparatus of any one of clauses 67 to 70, wherein the transparent carrier comprises glass. [Additional note 72] 72. The device of any one of claims 67 to 71, wherein the transparent carrier includes a dynamic release layer disposed on a surface of the transparent carrier, the dynamic release layer being disposed between the transparent carrier and the handle assembly. [Additional note 73] 73. The device of claim 72, wherein the dynamic release layer is disposed between the transparent carrier and the handle assembly. [Additional note 74] 74. The device of claim 72 or 73, wherein the dynamic release layer is mechanically responsive to an applied stimulus. [Additional note 75] 75. The device of claim 74, wherein the applied stimulus comprises ultraviolet light. [Additional note 76] 76. The device of any one of claims 67 to 75, wherein the handle substrate includes a handle release layer formed on a surface of the handle substrate, the handle release layer being disposed between the handle substrate and the discrete components. [Additional note 77] 77. The device of claim 76, wherein the handle release layer comprises a heat sensitive material. [Additional note 78] 80. The device of claim 76 or 77, wherein the handle release layer comprises a UV-sensitive material. [Additional note 79] 79. The device of claim 67, wherein the discrete components include an integrated circuit formed on a semiconductor substrate. [Additional note 80] An apparatus comprising a wafer-handle assembly mounted on a transparent carrier, the wafer including a wafer releasably attached to a handle substrate, discrete components being formed on the wafer, the wafer being configured such that (i) the discrete components formed on the wafer are ultra-miniature, or (ii) the wafer is ultra-thin, or (iii) both (i) and (ii). [Additional note 81] 81. The device of claim 80, wherein the handle substrate has a thickness of at least 50 μm. [Additional note 82] 82. The device of claim 80 or 81, wherein the transparent carrier is at least partially transparent to ultraviolet light. [Additional note 83] 83. The apparatus of any one of claims 80 to 82, wherein the transparent carrier comprises glass. [Additional note 84] The apparatus of any one of claims 80 to 83, wherein the transparent carrier includes a dynamic release layer disposed on a surface of the transparent carrier, the dynamic release layer being disposed between the transparent carrier and the wafer handle assembly. [Additional note 85] 85. The apparatus of claim 84, wherein the dynamic release layer is disposed between the transparent carrier and the wafer handle assembly. [Additional note 86] 86. The device of claim 84 or 85, wherein the dynamic release layer is mechanically responsive to an applied stimulus. [Additional note 87] 87. The device of claim 86, wherein the applied stimulus comprises ultraviolet light. [Additional note 88] 88. The apparatus of any one of claims 80 to 87, wherein the handle substrate includes a handle release layer formed on a surface of the handle substrate, the handle release layer being disposed between the handle substrate and the discrete components. [Additional note 89] 90. The device of claim 88, wherein the handle release layer comprises a heat sensitive material. [Additional Note 90] 90. The device of claim 88 or 89, wherein the handle release layer comprises a UV-sensitive material. [Additional Note 91] 91. The apparatus of any one of claims 80 to 90, wherein the wafer comprises a semiconductor wafer. [Additional note 92] embedding an assembly including discrete components in a flowable material, the assembly including discrete components being attached to a first handle substrate; thinning the embedded discrete components to a thickness of less than 50 μm; The method includes: [Additional Note 93] 93. The method of claim 92, wherein the assembly including the discrete components includes a handle assembly. [Additional note 94] The method of any one of claims 92 to 93, wherein embedding the assembly in a flowable material includes depositing a layer of flowable material on a surface of the first handle substrate. [Additional note 95] 95. The method of any one of claims 92 to 94, wherein the step of embedding the assembly in a flowable material comprises the step of placing a second handle substrate on a surface of the first handle substrate, the assembly being placed on the surface of the first handle substrate and the layer of flowable material being placed on the surface of the second handle substrate. [Additional note 96] 96. The method of claim 95, wherein the step of disposing a second handle substrate on the surface of the first handle substrate includes a step of contacting a layer of the flowable material disposed on the surface of the second handle substrate with the surface of the first handle substrate. [Additional Note 97] 97. The method of claim 95 or 96, wherein embedding the assembly in a flowable material comprises flowing a layer of the flowable material. [Additional note 98] 98. The method of claim 97, wherein the step of flowing the layer of flowable material includes exposing the layer of flowable material to ultraviolet (UV) light. [Additional Note 99] 99. The method of claim 97 or 98, wherein the step of flowing the layer of flowable material includes the step of exposing the layer of flowable material to a thermal stimulus. [Additional Note 100] 100. The method of any one of clauses 95 to 99, wherein the second handle substrate is at least partially transparent to UV light. [Additional Note 101] 101. The method of any one of clauses 95 to 100, wherein the second handle substrate comprises glass. [Additional Note 102] The method of any one of clauses 95 to 101, comprising removing the second handle substrate. [Additional Note 103] 103. The method of any one of claims 92 to 102, wherein the flowable material comprises a photoresist. [Additional Note 104] 104. The method of any one of claims 92 to 103, comprising removing the flowable material after thinning the embedded discrete components. [Additional Note 105] The method of claim 104, wherein the first handle substrate comprises a transparent carrier. [Additional Note 106] The method of claim 105, further comprising transferring the thinned discrete components from the transparent carrier to a device substrate. [Additional Note 107] 107. The method of any one of claims 92 to 106, comprising transferring the thinned discrete components to a third handle substrate. [Additional Note 108] The method of claim 107, wherein transferring the thinned discrete components to the third handle substrate comprises attaching the thinned discrete components to a handle release layer disposed on a surface of the third handle substrate. [Additional Note 109] 109. The method of claim 107 or 108, wherein the step of transferring the thinned discrete components to the third handle substrate comprises a step of releasing a handle release layer disposed between the discrete components and the first handle substrate. [Additional Note 110] The method of claim 109, wherein releasing the handle release layer includes applying a stimulus to the release layer. [Additional Note 111] 111. The method of claim 110, wherein the stimulus comprises UV light. [Additional Note 112] 113. The method of claim 110 or 112, wherein the stimulus comprises a thermal stimulus. [Additional Note 113] The method of any one of claims 107 to 112, comprising dicing the third handle substrate to form a handle assembly including thinned discrete components attached to corresponding portions of the third handle substrate. [Additional Note 114] The method of claim 113, wherein dicing the third handle substrate comprises dicing the third handle substrate and a handle release layer disposed on a surface of the third handle substrate, and the formed handle assembly comprises thinned discrete components attached to the handle release layer disposed on corresponding portions of the third handle substrate. [Additional Note 115] 15. The method of claim 113 or 114, comprising transferring the handle assembly to a device substrate. [Additional Note 116] The method of claim 115, comprising transferring the handle assembly to the device substrate using a pick-and-place approach. [Additional Note 117] 15. The method of claim 113 or 114, comprising transferring the handle assembly to a transparent carrier. [Additional Note 118] The method of claim 117, wherein transferring the handle assembly to a transparent carrier includes adhering the handle assembly to a carrier release layer disposed on the transparent carrier. [Additional Note 119] 19. The method of claim 117 or 118, comprising transferring the handle assembly from the transparent carrier to a device substrate. [Additional Note 120] The method of any one of claims 92 to 119, further comprising attaching the discrete component to the first handle substrate. [Additional Note 121] The method of claim 120, comprising attaching the discrete components to a handle release layer disposed on a surface of the first handle substrate. [Additional Note 122] The method of any one of claims 120 to 121, further comprising attaching the discrete components to the first handle substrate using a pick-and-place approach. [Additional Note 123] The method of any one of claims 120 to 122, further comprising attaching a plurality of discrete components to the first handle substrate. [Additional note 124] 124. The method of claim 123, wherein at least one of the plurality of discrete components is different from each of the other of the plurality of discrete components. [Additional Note 125] exposing a first substrate to a first stimulus, wherein an adhesion force between the first substrate and a discrete component bonded to the first substrate decreases in response to the first stimulus; transferring the discrete components from the first substrate to a second substrate; exposing the second substrate to a second stimulus, wherein adhesion between the first substrate and the discrete components decreases in response to the second stimulus; The method includes: [Additional note 126] The method of claim 125, further comprising the step of attaching a wafer to the first substrate, the discrete components being formed on the wafer. [Additional Note 127] The method of claim 126, further comprising dicing the wafer attached to the first substrate to form discrete components. [Additional note 128] The method of claim 127, wherein the step of attaching a wafer to the first substrate includes a step of attaching a wafer handle assembly to the first substrate, the wafer handle assembly including a wafer attached to a handle substrate. [Additional Note 129] The method of claim 128, further comprising dicing the wafer handle assembly attached to the first substrate to form handle assemblies, each handle assembly including a discrete component and a corresponding portion of the handle substrate. [Additional Note 130] 130. The method of any one of claims 125 to 129, wherein the first substrate comprises a dicing tape. [Additional Note 131] 131. The method of any one of claims 125 to 130, wherein exposing the first substrate to a first stimulus includes exposing the first substrate to ultraviolet light. [Additional Note 132] 132. The method of any one of claims 125 to 131, wherein exposing the first substrate to a first stimulus includes exposing the first substrate to heat. [Additional Note 133] 133. The method of any one of claims 125 to 132, wherein exposing the second substrate to a second stimulus includes exposing the second substrate to ultraviolet light. [Additional Note 134] 134. The method of any one of claims 125 to 133, wherein exposing the second substrate to a second stimulus includes exposing the second substrate to heat. [Additional Note 135] 135. The method of any one of claims 125 to 134, further comprising transferring the discrete components from the second substrate to a transparent carrier. [Additional Note 136] 136. The method of any one of claims 125 to 135, wherein the second substrate comprises a tape disposed on a vacuum chuck. [Additional Note 137] 137. The method of claim 136, further comprising applying a vacuum to the vacuum chuck, the applied vacuum securing the tape to the vacuum chuck. [Additional Note 138] dicing the attached wafer with the release layer disposed on a transparent carrier to form discrete components; exposing the release layer to a stimulus, wherein an adhesion between the release layer and the discrete components decreases in response to the stimulus; The method includes: [Additional Note 139] The method of claim 138, wherein exposing the release layer to a stimulus includes exposing the release layer to heat. [Additional Note 140] 140. The method of any one of claims 138 to 139, wherein exposing the release layer to a stimulus comprises exposing the release layer to ultraviolet light. [Additional Note 141] 141. The method of any one of claims 138 to 140, wherein an adhesion force between the release layer and the discrete components after exposure to a stimulus is sufficient for the discrete components to adhere to the release layer. [Additional Note 142] 142. The method of any one of claims 138 to 141, wherein the release layer comprises an adhesive layer and a dynamic release layer. [Additional Note 143] 143. The method of claim 142, wherein the adhesive layer loses adhesive strength when exposed to a stimulus. [Additional note 144] The method of any one of claims 142 to 143, further comprising exposing the release layer to a second stimulus, the dynamic release layer being mechanically responsive to the second stimulus. [Additional Note 145] 145. The method of claim 144, wherein one or more of the discrete components are transferred to a device substrate when the release layer is exposed to the second stimulus. [Additional note 146] The method of any one of clauses 138 to 145, wherein dicing the wafer includes dicing a wafer handle assembly to form handle assemblies, the wafer handle assemblies including a wafer attached to a handle substrate, each handle assembly including one of the discrete components and a corresponding portion of the handle substrate. [Additional note 147] 13. A method comprising: releasing discrete components from a release layer on a temporary handle by reducing adhesion between the release layer and the discrete components, the reduction comprising applying a stimulus that causes a change in surface morphology of the release layer. [Additional note 148] 148. The method of claim 147, wherein altering the surface morphology of the release layer comprises blisters. [Additional Note 149] 149. The method of claim 147 or 148, wherein the stimulus comprises heat or light. [Additional Note 150] 13. A method comprising: releasing discrete components from a release layer on a temporary handle by reducing adhesion between the release layer and the discrete components, the reduction comprising applying a stimulus that causes a phase transition of at least a portion of the release layer. [Additional Note 151] 151. The method of claim 150, wherein the phase transition comprises a solid to liquid transition or a solid to gas transition or both. [Additional Note 152] 152. The method of claim 150 or 151, wherein the stimulus comprises heat or pressure or both. [Additional Note 153] 13. A method comprising: releasing discrete components from a release layer on a temporary handle by reducing adhesion between the release layer and the discrete components, the reduction comprising applying a stimulus that changes a chemical structure or chemical composition or both of at least a portion of the release layer. [Additional Note 154] The method of claim 153, wherein a portion of the release layer is subjected to thermal decomposition. [Additional Note 155] 155. The method of claim 153 or 154, wherein a portion of the release layer is subjected to photolysis. [Additional Note 156] A method comprising the step of releasing a discrete component from a release layer on a temporary handle by reducing adhesion between the release layer and the discrete component, wherein recovery of adhesion after reduction in adhesion is prevented, inhibited or delayed. [Additional Note 157] A method comprising: releasing a discrete component from a release layer on a temporary handle by reducing adhesion between the release layer and the discrete component, the releasing step comprising releasing the discrete component without leaving any residue from the release layer on the discrete component after release. [Additional note 158] 13. A method comprising releasing discrete components from a release layer of a temporary handle and depositing the discrete components and a handle substrate, the release layer having a thickness of less than 10 μm prior to release. [Additional Note 159] The method of claim 158, wherein the release layer comprises a single layer. [Additional Note 160] 159. The method of claim 158, wherein the release layer comprises a first layer and a second layer. [Additional Note 161] The method of claim 160, wherein the release layer includes a first layer attached to the handle and a second layer intended for deposition of discrete components. [Additional note 162] 162. The method of claim 160 or 161, wherein the second layer is parallel to the first layer. [Additional Note 163] The method of any one of clauses 160 to 162, wherein the second layer is UV-sensitive. [Additional note 164] The method of any one of claims 160 to 163, wherein the second layer is heat sensitive. [Additional Note 165] The method of any one of claims 160 to 164, wherein the first layer is a permanent adhesive. [Additional note 166] The method of claim 164, wherein the heat sensitivity of the second layer reduces adhesive strength in response to the application of thermal energy. [Additional Note 167] The method of claim 164, wherein the heat sensitivity of the second layer increases adhesive strength in response to the application of thermal energy. [Additional note 168] The method of claim 163, wherein the UV sensitivity increases adhesive strength in response to irradiation with UV light. [Additional Note 169] The method of claim 163, wherein the UV sensitivity reduces adhesive strength in response to irradiation with UV light. [Additional Note 170] 170. The method of any one of claims 158 to 169, further comprising transferring the discrete components onto the handle substrate for contacting a device substrate. [Additional note 171] 171. The method of claim 170, further comprising releasing the discrete components from the handle substrate for deposition on the device substrate. [Additional note 172] 172. The method of claim 171, wherein depositing the discrete components on the device substrate includes bonding the discrete components to the device substrate. [Additional note 173] 173. The method of claim 172, wherein the step of releasing the discrete component from the handle is performed simultaneously with the step of bonding the discrete component to the device substrate. [Additional Note 174] 174. The method of claim 172 or 173, wherein the step of releasing the discrete component from the handle is in response to a step of bonding the discrete component to the device substrate. [Additional note 175] 174. The method of claim 172 or 173, wherein the step of releasing the discrete component from the handle is caused by bonding the discrete component to the device substrate. [Additional note 176] 176. The method of any one of clauses 172 to 175, wherein the step of releasing the discrete component from the handle is completed after the step of bonding the discrete component to the device substrate. [Additional Note 177] 176. The method of any one of claims 172 to 175, wherein the discrete components are released from the handle by bonding to the device substrate. [Additional note 178] The method of any one of claims 172 to 177, wherein the bonding step further includes the step of providing thermal energy or UV light for both bonding the discrete component to the substrate and releasing the discrete component from the handle. [Additional note 179] 179. The method of any one of clauses 171 to 178, wherein the handle substrate remains in contact with the device substrate upon releasing the discrete components from the handle substrate. [Additional Note 180] 180. The method of claim 179, comprising removing the handle substrate from the discrete components. [Additional note 181] The method of claim 180, wherein the step of removing the handle substrate includes applying at least one of the following: a brush, a blade, compressed air, a vacuum force, vibration, or gravity, or any combination of two or more thereof. [Additional note 182] 182. The method of any one of clauses 158 to 181, wherein the handle substrate comprises a thickness between 49 and 801 microns. [Additional note 183] 183. The method of any one of clauses 158 to 182, wherein the handle substrate comprises a thickness between 100 and 800 microns. [Additional note 184] 184. The method of any one of clauses 158 to 183, wherein the handle substrate comprises a thickness between 300 and 800 microns. [Additional note 185] 185. The method of any one of claims 158 to 184, wherein at least one side of the handle substrate comprises a length between 400 and 600 microns. [Additional note 186] 13. An apparatus comprising: a discrete component attached to a temporary handle via a release layer, the release layer configured to undergo a change in surface morphology in response to an applied stimulus. [Additional note 187] The device of claim 186, wherein the change in surface morphology comprises a blister. [Additional note 188] 188. The device of any one of claims 186 to 187, wherein the change in surface morphology comprises a plurality of blisters across the surface of the release layer. [Additional note 189] 13. An apparatus comprising: a discrete component attached to a temporary handle via a release layer, at least a portion of the release layer configured to undergo a phase transition in response to an applied stimulus. [Additional Note 190] 189. The device of claim 189, wherein the phase transition includes a solid to liquid transition or a solid to gas transition or both. [Additional note 191] 1. An apparatus comprising: a discrete component attached to a temporary handle via a release layer, at least a portion of the release layer configured to undergo a change in chemical structure or chemical composition, or both, in response to an applied stimulus. [Additional note 192] The device of claim 191, wherein the change includes thermal decomposition. [Additional note 193] The device of claim 191 or 192, wherein the change includes photodecomposition. [Additional note 194] 1. An apparatus comprising a discrete component attached to a temporary handle via a release layer, the release layer configured to prevent, inhibit or delay recovery of adhesion of the release layer following a decrease in adhesion between the release layer and the discrete component. [Additional note 195] 13. An apparatus comprising: a discrete component attached to a temporary handle via a release layer, the release layer having a thickness of less than 10 μm. [Explanation of symbols]

[0283] 10, 30, 452 Discrete Components 12, 614, 704 Device Substrate 14 Mounting elements 100, 101, 103, 500 Handle Assembly 102 Active Surface 104, 104a, 304 1st page 105, 105a, 305, 458, 464 Handle release layer 106, 106a, 306 2nd side 108, 108a, 308 Handle board 150, 160, 180, 450 processes 300 wafers 302 Support Substrate 310 Active Layer 320, 370, 501, 550, 570 Wafer transfer approach 372, 552 Dicing 374, 580 Materials with controllable adhesive strength 376, 582 Stimuli such as heat or ultraviolet rays 400 Wafer Handle Assembly 410 Packaging process for ultra-small and ultra-thin discrete components 454 First handle board 456 Second handle board 460 Layer of flowable material 462 3rd handle board 502 Blade 504 Laser Beam 506 Dicing Tape 508 UV rays, distance 510 Vacuum Chuck, Oversized Handle Assembly 512 Heat-Releasable Tape 554 Transfer onto transparent carrier 600 556 Non-Contact Approach 572 Dicing Blade 574 Stealth Dicing Approach 576 Transfer to a vacuum chuck covered with thermal release tape 578 Release to Invisible Carrier 600 Transparent Carrier 602 Vacuum Chuck 604 Dynamic Release Layer (DRL) 610 Transfer onto device substrate 612 Discrete component joining tool 618 Adhesive surface 700 Pick and Place Approach 702 Tools 708 Mounting surface 720 Process for packaging ultra-small and / or ultra-thin discrete components in a face-up configuration 800 Laser-assisted non-contact transfer method 802 Adhesive layer 804 Laser light 806 Blister 810 Oversized Handle Assembly 812, 1202 distance 815 Handle release layer 818 Temporary Board Handle 1000 A process for packaging ultra-small and ultra-thin discrete components in a flip-chip configuration 1106 Conductive materials 1300 Handle Assisted Packaging Process

Claims

[Claim 1] An apparatus or method as described in the specification and drawings.

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