Adhesive tape for accepting individual components

Abstract

This relates to assembling individual components on a circuit board. [Solution] The system comprises a vacuum chuck and a tape. The tape comprises a flexible polymer substrate and an adhesive die-capturing film positioned on the flexible polymer substrate facing the front of the flexible polymer substrate. The tape is held in the vacuum chuck by suction applied to the rear surface of the flexible polymer substrate.

Description

Technical Field

[0001] Priority Claim This application claims priority to U.S. Patent Application No. 62 / 949,013, filed on December 17, 2019, the content of which is hereby incorporated by reference in its entirety.

[0002] This description generally relates to assembling individual components on a substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0004] In an aspect, the system includes a vacuum chuck and a tape. The tape includes a flexible polymer substrate and an adhesive die capture film disposed on the flexible polymer substrate facing the front surface of the flexible polymer substrate. The tape is held by the vacuum chuck by suction applied to the back surface of the flexible polymer substrate.

[0005] Embodiments may include one or a combination of two or more of the following features.

[0006] The system includes an individual component support fixture disposed facing the side of the tape where the adhesive die capture film is disposed, with a gap defined between the tape and the individual component support fixture. The system includes an optical system, and the individual component support fixture is disposed between the optical system and the tape. The optical system includes a light source and an optical element. The optical element includes a lens. The system includes an individual component assembly disposed on the individual component support fixture.

[0007] The system comprises individual components that are partially embedded in or positioned within the covering.

[0008] The adhesive die-capture film contains a viscoplastic adhesive material. The viscoplastic adhesive material contains a Bingham fluid.

[0009] The adhesive die-capture film contains a photosensitizer.

[0010] The adhesive die-capture film contains a chemical catalyst.

[0011] The adhesive die-capture film contains a viscoelastic adhesive material. The viscoelastic adhesive material contains a pressure-sensitive adhesive.

[0012] The adhesive die-capture film contains an adhesive elastic material.

[0013] The adhesive die-trapping film is configured to undergo structural changes, phase changes, or chemical changes in response to irradiation of the material.

[0014] The tape features a dynamic release structure positioned on the front surface of a flexible polymer substrate, and the adhesive die-capturing film is positioned within the dynamic release structure.

[0015] The system features a dynamic release structure positioned on the rear surface of a flexible polymer substrate.

[0016] In one embodiment, the method includes the steps of: placing a tape in a vacuum chuck, wherein the tape comprises a flexible polymer substrate and an adhesive die-capturing film disposed on the flexible polymer substrate; and applying suction to the tape in order to hold the tape in the vacuum chuck.

[0017] The embodiments may include one or any combination of two or more of the following features:

[0018] The method includes the step of receiving individual components in or on the surface of an adhesive die capture film.

[0019] The method includes the step of providing a die placement system with a tape in which individual components are arranged within or on the surface of an adhesive die-capturing film. The die placement system comprises one or more of a die bonding system, a die classification system, a die mixing system, or a die pitch re-determination system.

[0020] The method includes the step of releasing individual components from an adhesive die-trapping film by a laser-assisted transfer process. The tape comprises a dynamic release structure disposed on a flexible polymer substrate, and the adhesive die-trapping film is disposed on the dynamic release structure, and the step of releasing individual components from the adhesive die-trapping film by a laser-assisted transfer process includes irradiating the dynamic release structure of the tape through the flexible polymer substrate to bring about the release of the individual components. The adhesive die-trapping film is configured to release individual components in response to irradiation of the material, and the step of releasing individual components from the adhesive die-trapping film by a laser-assisted transfer process includes irradiating the adhesive die-trapping film through the flexible polymer substrate to bring about the release of the individual components. The adhesive die-trapping film is disposed on a first side of the flexible polymer substrate, and the tape comprises a dynamic release structure disposed on a second side of the flexible polymer substrate, and the step of releasing individual components from the adhesive die-trapping film by a laser-assisted transfer process includes irradiating the dynamic release structure through the flexible polymer substrate to bring about the release of the individual components. The method includes the steps of attaching a dynamic release structure to a rigid support and irradiating the dynamic release structure through the rigid support to bring about the release of individual components.

[0021] The method includes the step of interconnecting individual components to a substrate while the individual components are positioned in or on the surface of an adhesive die-capture film. The method includes the step of interconnecting individual components to a substrate in a die stamping system.

[0022] The method includes the steps of transferring individual components from an adhesive die capture film to a second substrate, and providing the second substrate including the individual components to a die placement system. The die placement system comprises one or more of a die bonding system, a die sorting system, a die mixing system, or a die pitch re-determination system.

[0023] The method includes the steps of transferring individual components from an adhesive die capture film to a second substrate, and providing the second substrate including the individual components to a die stamping system for interconnecting the individual components to a device substrate.

[0024] The adhesive die capture film contains a photosensitizer, and the method includes the step of irradiating the adhesive die capture film with ultraviolet light to crosslink the photosensitive polymer after receiving the individual components.

[0025] The adhesive die capture film contains a chemical catalyst, and the method includes the step of crosslinking the adhesive die capture film by the action of the chemical catalyst after receiving the individual components.

[0026] The method includes the step of exposing the adhesive die capture film to heat to cure the adhesive die capture film after receiving the individual components.

[0027] The method includes the step of drying the adhesive die capture film after receiving the individual components to cure the adhesive die capture film.

[0028] The method includes the step of irradiating an individual component assembly, wherein the irradiation releases the individual components from the individual component assembly, and the step of receiving the released individual components into or onto an adhesive die capture film. The individual component assembly comprises a dynamic release structure disposed on a carrier, the individual components are disposed on the dynamic release structure, and the step of irradiating the individual components includes irradiating the dynamic release structure. Irradiating the dynamic release structure includes inducing ablation of at least a portion of the dynamic release structure. Irradiating the dynamic release structure includes inducing a change in the surface morphology of the dynamic release structure. Irradiating the dynamic release structure includes inducing blister formation on the surface of the dynamic release structure.

[0029] The method includes the step of removing a protective film from the adhesive die capture film before receiving the individual components.

[0030] The method includes the step of removing the received individual components from the adhesive die capture film and the step of reusing the tape to receive a second individual component into or onto the adhesive die capture film. The adhesive die capture film comprises an elastic adhesive material.

[0031] In an aspect, a tape for receiving individual components comprises a flexible polymer substrate, an adhesive die capture film disposed on the flexible polymer substrate, the adhesive die capture film including one or more of a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material, and a protective film disposed on the adhesive die capture film.

[0032] Embodiments may include one of the following features, or any combination of two or more.

[0033] The adhesive die capture film includes a pressure-sensitive adhesive.

[0034] The adhesive die capture film includes a Bingham fluid.

[0035] The adhesive die capture film includes a crosslinking accelerator.

[0036] The crosslinking accelerator contains a photosensitive polymer.

[0037] Crosslinking accelerators include chemical catalysts.

[0038] An adhesive die-capturing film is positioned in front of the flexible polymer substrate, and the rear surface of the flexible polymer substrate contains the adhesive material. The tape comprises a rigid substrate, and the flexible polymer substrate is adhered to the rigid substrate by the flexible polymer substrate.

[0039] The flexible polymer substrate is held in the vacuum chuck by suction.

[0040] The tape features a dynamic release structure placed on a flexible polymer substrate, and the adhesive die-capturing film is positioned within the dynamic release structure.

[0041] The adhesive die trapping film is configured to release individual components in response to irradiation of the material.

[0042] The adhesive die-capturing film is positioned on the first surface of the flexible polymer substrate, and the tape includes a dynamic release structure positioned on the second surface of the flexible polymer substrate.

[0043] The flexible polymer substrate can be removed from the adhesive die-capture film.

[0044] The protective film can be removed from the adhesive die capture film.

[0045] In one embodiment, the method comprises the steps of forming an adhesive die-capture film on a flexible polymer substrate facing the front surface of the flexible polymer substrate, wherein the adhesive die-capture film comprises one or more viscoelastic adhesive materials, viscoplastic adhesive materials, or elastic adhesive materials, and arranging a protective film over the adhesive die-capture film.

[0046] The embodiments may include one or any combination of two or more of the following features:

[0047] The method includes the step of forming an adhesive die-capturing film of a pressure-sensitive adhesive.

[0048] The method includes the step of forming an adhesive die-capturing film of Bingham fluid.

[0049] The method includes the step of forming an adhesive die-capture film of an ultraviolet-sensitive polymer and a crosslinking agent.

[0050] The step of forming an adhesive die-capturing film includes forming the adhesive die-capturing film by a direct coating technique.

[0051] The step of forming an adhesive die-capturing film includes forming the adhesive die-capturing film by a transfer coating technique.

[0052] The method includes the steps of placing a dynamic release structure on the front surface of a flexible polymer substrate and forming an adhesive die-capturing film on the dynamic release structure.

[0053] The method includes the step of forming an adhesive die trapping film such that the adhesive die trapping film is configured to release individual components from the adhesive die trapping film in response to irradiation of the adhesive die trapping film.

[0054] The method includes the step of placing a dynamic release structure on the rear surface of a flexible polymer substrate.

[0055] The method includes the step of applying suction to the rear surface of a flexible polymer substrate by a vacuum chuck in order to hold the flexible polymer substrate in the vacuum chuck.

[0056] The method includes the step of attaching the rear surface of a flexible polymer substrate to a rigid substrate.

[0057] The method includes the step of removing a flexible polymer substrate from an adhesive die-capture film in order to expose the rear surface of the die-capture film. The method also includes the step of attaching the rear surface of the die-capture film to a rigid substrate.

[0058] In one embodiment, the method includes the steps of: removing a post-protective layer from an adhesive die-capture film to expose the rear surface of the adhesive die-capture film, wherein the adhesive die-capture film forms part of a die-capture tape comprising a post-protective layer, the adhesive die-capture film is positioned on the post-protective layer, a pre-protective layer is positioned in front of the adhesive die-capture film, and the adhesive die-capture film comprises one or more of a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material; adhering the rear surface of the adhesive die-capture film to a substrate; removing the pre-protective layer from the adhesive die-capture film to expose the front surface of the adhesive die-capture film; and receiving individual components on the front surface of the adhesive die-capture film, wherein the individual components are transferred in a laser-assisted transfer process.

[0059] The embodiments may include one or any combination of two or more of the following features:

[0060] The adhesive die-capturing film comprises a photosensitizer, and the method includes illuminating the adhesive die-capturing film with ultraviolet light after it has accepted individual components in order to crosslink a photosensitive polymer.

[0061] The adhesive die-capturing film comprises a chemical catalyst, and the method includes the step of crosslinking the adhesive die-capturing film by the action of the chemical catalyst after accepting individual components.

[0062] The method includes, after accepting the individual components, exposing the adhesive die-capturing film to heat in order to cure the adhesive die-capturing film.

[0063] The method includes the step of drying the adhesive die-capture film after it has received the individual components in order to cure the adhesive die-capture film.

[0064] The method includes the steps of removing the accepted individual components from the front surface of the adhesive die-capturing film and reusing the adhesive die-capturing film to accept a second individual component on the front surface of the adhesive die-capturing film.

[0065] In one embodiment, the tape for receiving individual components comprises a flexible polymer substrate and a film disposed on the flexible polymer substrate, comprising one or more viscoelastic adhesive materials, viscoplastic adhesive materials, or elastic adhesive materials, and configured to undergo a structural change, phase change, or chemical change in response to irradiation of the film.

[0066] The embodiments may include one or any combination of two or more of the following features:

[0067] The film is configured to form blisters in response to the absorption of incident radiation.

[0068] In this embodiment, the tape for receiving individual components comprises a flexible polymer substrate, a dynamic release structure disposed on the flexible polymer substrate, and an adhesive die-capturing film disposed on the dynamic release structure.

[0069] The embodiments may include one or any combination of two or more of the following features:

[0070] The adhesive die-capture film comprises one or more of the following: viscoelastic adhesive material, viscoplastic adhesive material, or elastic adhesive material.

[0071] The dynamic release structure is configured to undergo a structural change, phase change, or chemical change in response to irradiation. The film is configured to form a blister in response to absorbing incident radiation.

[0072] In this embodiment, the tape for receiving individual components comprises a flexible polymer substrate, an adhesive die-capturing film disposed on a first surface of the flexible polymer substrate, and a dynamic release structure disposed on a second surface of the flexible polymer substrate.

[0073] The embodiments may include one or any combination of two or more of the following features:

[0074] The adhesive die-capture film comprises one or more of the following: viscoelastic adhesive material, viscoplastic adhesive material, or elastic adhesive material.

[0075] The dynamic release structure is configured to undergo a structural change, phase change, or chemical change in response to irradiation. The film is configured to form a blister in response to absorbing incident radiation.

[0076] Details of one or more embodiments are described in the accompanying drawings and the following description. Other features and advantages will become apparent from the description and drawings and the claims. [Brief explanation of the drawing]

[0077] [Figure 1] This is a diagram of a laser-assisted transfer system. [Figure 2] This is a diagram of tape for receiving the individual components that have been transferred. [Figure 3] This is a diagram of tape for receiving the individual components that have been transferred. [Figure 4] This is a diagram of tape for receiving the individual components that have been transferred. [Figure 5] This is a diagram of tape for receiving the individual components that have been transferred. [Figure 6A] This is a diagram of the die-capture membrane for receiving the transferred individual components. [Figure 6B] This is a diagram of the die-capture membrane for receiving the transferred individual components. [Figure 6C] This is a diagram of the die-capture membrane for receiving the transferred individual components. [Figure 7] This is a diagram of tape for receiving the individual components that have been transferred. [Figure 8A] This is a diagram of tape for receiving the individual components that have been transferred. [Figure 8B] This is a diagram of tape for receiving the individual components that have been transferred. [Modes for carrying out the invention]

[0078] Here, we describe a tape for receiving individual components such as light-emitting diodes (LEDs) transferred to the tape by a laser-assisted transfer process. The tape comprises an adhesive die-capturing film which may contain a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material.

[0079] Generally, individual components transferred via a laser-assisted transfer process travel at high speed vertically (e.g., downwards) across the gap between the support and the target substrate. Due to imperfections in the material, imperfections in the transfer process, or both, the direction of travel of individual components in a laser-assisted transfer process may have a lateral (e.g., horizontal) component. This lateral component of the direction of travel of individual components may cause the individual component to move laterally, bounce off the substrate, rotate so that the individual component is no longer flat on the tape (sometimes referred to as "tombstone"), or a combination of two or more of these effects, when the individual component hits the target substrate, for example by sliding or lateral movement. Furthermore, even when the direction of travel of individual components is vertical overall, the individual components may still be susceptible to one or more of these effects due to imperfections or surface hardness of the target substrate surface. These effects can negatively impact the accuracy of the placement of individual components on the target substrate, the yield of the laser-assisted transfer process, or both.

[0080] The use of tape with an adhesive die-capturing film can help reduce the occurrence of adverse effects such as naturally occurring displacement of the transferred individual components, rebound of individual components from the tape surface upon contact with the tape, or "tombstone" of individual components. As a result, excellent accuracy in the placement of individual components onto the tape can be achieved. Furthermore, the use of tape when accepting the substrate for laser-assisted transfer of individual components can improve the efficiency of the laser-assisted transfer process, compared to gel-coated substrates, for example, because the tape can be disposable, thereby eliminating the need for substrate cleaning and the need for reconfiguration for repeated acceptance of transferred substrate components.

[0081] Referring to Figure 1, the tape 100 comprises a flexible polymer substrate 102 with an adhesive die-capturing film 104 (to be further discussed later) positioned on the front surface 106 of the substrate 102. In the context of this description, "tape" generally refers to a multilayer structure, such as a multilayer structure, having sufficient mechanical strength to become a self-supporting element. In the context of this description, "film" generally refers to a single layer, such as a layer of tape. The flexible polymer substrate 102 can provide mechanical support that allows the tape 100 to become a self-supporting, flexible element.

[0082] Tape 100 is intended for use as a target substrate to receive individual components 110 transferred via a laser-assisted transfer process. The term individual components generally refers to any unit that becomes part of a product or electronic device, such as electronic, electromechanical, photovoltaic, photonic, or optoelectronic components, modules, or systems, such as any semiconductor material on which a circuit is formed. In one example, an individual component may be a light-emitting diode (LED). Individual components can be ultrathin, meaning they have 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, or 5 μm or less. Individual components can be ultraminiature, meaning they have a maximum length or width dimension of 300 μm or less per side, 100 μm or less per side, 50 μm or less per side, 20 μm or less per side, or 5 μm or less per side. Individual components can be both ultrathin and ultraminiature.

[0083] In the laser-assisted transfer process, individual components 110 are attached to a support 112 by a dynamic release structure 114, and the support 112 and the dynamic release structure 114 form an individual component assembly 115. The back side of the support 112 is irradiated by radiation such as laser light, causing a change in the dynamic release structure (which will be discussed in more detail later) that releases the individual components 110 from the support 112. The individual components 110 are moved away from the support 112 (for example, downward) and land on the adhesive die-capturing film 104 of the tape 100. The adhesive die-capturing film 104 accepts the individual components 110 and maintains them in their target position, while reducing post-transfer movement of the individual components 110 on the tape 100, rebound of the individual components 110 from the tape 100, tombstone of the individual components, or any two or more of these.

[0084] The adhesive die-capture film 104 consists of a die-capture material, which is an adhesive material capable of receiving ancillary individual components, holding the individual components in substantially the same position once they are received, and positioning the individual components flat on the tape, thereby preventing, for example, slippage, rebound, or tombstone of the individual components. For example, the die-capture material may be a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material.

[0085] In one example, the adhesive die-capture film 104 includes a viscoelastic adhesive die-capture material. A viscoelastic material is a viscous material that exhibits elasticity in response to an applied force. Viscoelastic materials are generally hard (for example, harder than viscoplastic materials), and therefore individual components transferred to the viscoelastic material may bounce back. The adhesiveness of the viscoelastic material used in the adhesive die-capture film 104 can help prevent such bouncing. With a viscoplastic material, when the transferred individual components are removed from the viscoelastic adhesive die-capture film, the viscoelastic adhesive material can remain on the tape and not transfer to the removed individual components, thus eliminating the need to wash the individual components to remove the adhesive.

[0086] In certain examples, the adhesive die-capture film 104 includes a viscoelastic adhesive die-capture material such as a pressure-sensitive adhesive. For example, if the viscoelastic adhesive die-capture material is a pressure-sensitive adhesive, when the individual component 110 lands on the adhesive die-capture film 104, the individual component 110 exerts force on the adhesive die-capture film 104, activating the pressure-sensitive adhesive for adhesion to the individual component 110. As a result, the rebound and movement of the individual component 110 after transfer are limited.

[0087] In one example, the adhesive die-retaining film 104 includes a viscoplastic adhesive die-retaining material having a yield stress, such as a Bingham plastic material or a Bingham pseudoplastic material. A viscoplastic material is a viscous material that exhibits plastic deformation when the applied force exceeds its yield stress. Examples of viscoplastic materials include adhesive fluxes and gels (e.g., alcohol gels, hydrogels, organogels, or other types of gels).

[0088] In some examples, the adhesive die-capture film includes a material (e.g., a viscoelastic or viscoplastic adhesive material) that hardens after receiving transferred individual components to hold them in place, for example, by crosslinking or drying. For example, the adhesive die-capture film may include a viscoelastic or viscoplastic adhesive die-capture material containing a crosslinking accelerator such as a photosensitive polymer (e.g., an ultraviolet (UV) photosensitizer) or a chemical catalyst that initiates and promotes a photopolymerization or crosslinking reaction. After the individual components are transferred to the adhesive die-capture film, the die-capture material can be converted into a solid material by the action of the crosslinking accelerator, for example, by the application of light (e.g., ultraviolet light), by chemical exposure (e.g., exposure to a chemical catalyst), or by other means. In some examples, the die-capture film may be crosslinked by thermosetting. In some examples, the adhesive die-capture film may include a drying material, for example, that hardens by evaporation.

[0089] In one example, the adhesive die capture film 104 includes an elastic adhesive material, such as a solid elastic material with high tackiness and sufficient elasticity to absorb the impact of individual components, for example, preventing the individual components 110 from bouncing back. An elastic material is a material that deforms elastically in response to an applied force. Examples of elastic adhesive materials include silicone-based polymers such as polydimethylsiloxane (PDMS). The elastic and adhesive die capture material acts elastically when accepting the individual components 110, which means there is little to no structural change (e.g., structural damage) to the adhesive die capture film 104. The adhesive die capture film 104 containing the elastic adhesive material can be reused for multiple laser transfer processes due to the minimal structural change that occurs in the adhesive die capture film 104 during the acceptance of the individual components 110. For example, a tape 100 (or another substrate such as a rigid substrate) having an adhesive die-capturing film 104 containing an elastic adhesive material can be a reusable component in the laser transfer process, and the process efficiency can be improved by eliminating the step of preparing a receiving substrate on which the adhesive die-capturing film 104 is placed for each laser transfer.

[0090] Referring to Figure 2, in an example where the adhesive die-capture film 104 contains a viscoelastic adhesive die-capture material such as Bingham fluid, when the individual components 110 are transferred to the tape 100, the individual components 110 are captured by the adhesive die-capture film 104 containing the viscoplastic adhesive material and are partially embedded in the coating (as shown in Figure 2) or positioned on top of the coating. Partial embedding allows the lower surface 116 of the individual component 110 to be below the upper surface 118 of the adhesive die-capture film 104, while the upper surface 120 of the individual component 110 is above the upper surface 118 of the adhesive die-capture film 104. When the individual components 110 are partially embedded in or positioned within the adhesive die-capture film 104, the rheological properties of the viscoplastic adhesive material (e.g., Bingham fluid) prevent the individual components 110 from simultaneously shifting or floating. Therefore, the precision and accuracy of component placement can be enhanced through the use of an adhesive die-capture film containing a viscoplastic adhesive material such as Bingham fluid.

[0091] Referring again to Figure 1, in the laser-assisted transfer process, the individual component assembly 115 is positioned on the individual component support fixture 150. The individual component support fixture 150 is positioned facing the tape 100 on which the adhesive coating 104 is placed, and is separated from the tape 100 by a gap 152. The individual component assembly 115 comprises individual components 110 attached to a support 112, which can be a rigid support such as a glass or rigid polymer substrate, or a flexible support such as a tape. The individual components 110 are attached to the support 112 by a dynamic release structure 114, which can be a single-layer or multi-layer structure. The dynamic release structure is formed from a material that undergoes a chemical change, phase change, or structural change when irradiated with light such as ultraviolet light. For example, the dynamic release structure can be made from a material that absorbs incident light, thereby generating an expanding gas and forming a blister within the material. The individual component support fixture 150 is an element configured to hold the support 112 in position for laser-assisted transfer. For example, when the support 112 is a flexible support such as tape, the individual component support fixture 150 may include a support plate positioned on a support frame, and the support 112 is held in contact with the support plate by the application of suction. When the support 112 is a rigid support, the individual component support fixture may include slots, fasteners, adhesives, or other guiding elements for holding the support 112 in place.

[0092] The individual component support fixture 150 is positioned between the tape 100 and the optical system 160. The optical system 160 comprises a light source 162, such as a laser, and one or more optical elements 164, such as lenses or diffracting optical elements (e.g., beam splitters). Light from the light source 162 is incident on one or more optical elements 164 that direct the light toward the back side of the support 112. The support 112 is transparent to the wavelength of the incident light from the light source 162, meaning that at least some radiation of a given wavelength passes through the support 112. The radiation passes through the support 112 and is incident on the region of the dynamic release structure 114.

[0093] The incident light causes a structural, phase, or chemical change in at least a portion of the thickness of the dynamic release structure 114 in the region where the radiation is incident, resulting in the release of the individual components 110 from the support 112. In some examples, the incident light can cause ablation in at least a portion of the thickness of the dynamic release structure 114 in the region where the radiation is incident. The ablation generates trapped gas, which expands and generates stress in the dynamic release structure 114. The stress deforms at least a portion of the material of the dynamic release structure 114, forming one or more blisters that exert mechanical forces on the individual components 110. When the mechanical force exerted by the blisters is sufficient to overcome adhesion between the individual components 110 and the dynamic release structure 114, the mechanical force exerted by the blisters (in combination with gravity) moves the individual components 110 away from the support 112 (e.g., downward) for transfer to the tape 100. In some examples, the incident light can cause a change in the morphology of the dynamic release structure 114, such as the surface morphology. For example, changes in surface morphology may include the formation of blisters on the surface of the dynamic release structure. In some examples, incident light may induce a phase transition, such as dissolution or sublimation, in at least a portion of the thickness of the dynamic release structure 114. In some examples, incident light may induce a chemical change, such as thermal or photodegradation, in at least a portion of the thickness of the dynamic release structure 114. In some examples, a structural change, phase change, or chemical change in at least a portion of the thickness of the dynamic release structure 114 may be induced at least partially by heat, such as by a combination of light and heat.

[0094] A further description of the laser-assisted transfer process can be found in U.S. Patent Application Publication No. 2014 / 0238592, which is incorporated herein by reference in its entirety.

[0095] During the laser-assisted transfer process, the tape 100 may be placed in a vacuum chuck 130 so that individual components 110 are transferred to the tape 100 held in the vacuum chuck 130. For example, the tape 100 is held in place in the vacuum chuck 130 by suction applied to the rear surface 132 of the flexible polymer substrate 102.

[0096] The tape 100, along with one or more individual components 110 attached thereto, can be used as a source tape for transferring the individual components 110 to another substrate. In one example, the tape 100 with the individual components 110 attached may be provided to a die placement system such as a die bonding system, die mixing system, die sorting system, or die pitch re-determination system for transferring the individual components from the tape 100 to one or more other substrates. Die pitch re-determination means positioning the individual components on the target substrate such that the pitch of the individual components to each other differs from the pitch of the individual components to each other on their source substrates. In another example, the tape 100 with the individual components 110 attached can be used as a stamp in a die stamping process, where the tape 100 with the individual components 110 attached is pressed against a receiving substrate such as a printed circuit board, and the individual components 110 are interconnected to the receiving substrate. In yet another example, the tape 100 can be provided as an intermediate carrier substrate to which the individual components 110 are transferred (e.g., by a pick-and-place process) from the tape 100 to a second flexible or rigid carrier substrate. Once the individual components 110 are positioned on the second support substrate, the second support substrate can be supplied to die placement systems such as die bonding systems, die mixing systems, die classification systems, or die pitch re-determination systems, or it can be used as a stamp in a die stamping process for transferring the individual components to a target substrate. The compatibility of the tape 100 with downstream processing operations such as die placement operations such as die bonding, die mixing, die classification, or die pitch re-determination facilitates the performance of such operations, which can easily, quickly, and inexpensively follow up with laser-assisted transfer of individual components to the tape 100.

[0097] Referring to Figure 3, an adhesive die-capture film 104 is formed on the front surface of a flexible polymer substrate 102 to create the tape 100. In some examples, the die-capture material 104 is formed by direct coating, where the die-capture material is directly coated onto the flexible polymer substrate 102 to form the die-capture film 104. In some examples, the die-capture material is formed by transfer coating, where the die-capture material is first coated onto a release liner and then transferred onto the flexible polymer substrate, for example, by lamination, to form the adhesive die-capture film 104. The material properties and thickness of the adhesive die-capture film 104 can be controlled during tape fabrication, and the properties and thickness can be specially fabricated for specific applications (e.g., the shape of specific individual components), providing high accuracy, precision, and yield for laser-assisted transfer of individual components to the tape.

[0098] The protective film 140 is placed over the adhesive die-capture film 104 to prevent the adhesive die-capture film 104 from inadvertently adhering to other objects before accepting individual components, to protect the die-capture material from contamination or environmentally introduced material degradation, or both. The protective film 140 can be removed from the adhesive die-capture film 104 while leaving the adhesive die-capture film 104 intact. The protective film 140 may be a self-supporting, flexible film such as a release liner. In some examples, the protective film may be formed from a polymer with low interfacial adhesion and non-stick properties, such as polytetrafluoroethylene or similar fluororesins, polyethylene, polyvinyl chloride, polypropylene, or other suitable polymers. In some examples, the protective film may be a polymer whose non-stick and low adhesion properties are provided by treatment, such as by coating the protective film with a non-stick release agent. The protective film may have properties such as low permeability, moisture protection, ultraviolet (UV) light protection, or other properties that can help prevent degradation of the underlying die-capture material, which may result from, for example, exposure to the environment. The protective film 140 is removed before the laser-assisted transfer process, such as before placing the tape 100 in the vacuum chuck.

[0099] Figure 4 shows an example of a tape 400 for receiving individual components in a laser-assisted transfer process. The tape 400 comprises a dynamic release structure 414 positioned between a flexible polymer substrate 402 and an adhesive die-capturing film 404. The dynamic release structure 414 may be a single-layer or multi-layer dynamic release structure. The tape 400 can act as a substrate for receiving individual components 110 to be transferred in a laser-assisted transfer process, as previously described. The tape 400 with the individual components attached can then be used as a source tape in a subsequent laser-assisted transfer process to transfer the individual components 110 to another substrate. For example, the tape 400 can be mounted on an individual component support fixture, and an optical system can be used to illuminate the rear surface 416 of the flexible polymer substrate 402. The flexible polymer substrate 402 is transparent to the wavelength of incident light so that light passes through the flexible polymer substrate and enters the region of the dynamic release structure 414. Light incident on the dynamic release structure 414 causes a structural change, phase change, or chemical change, such as ablation, phase change, or morphology change, to at least a portion of the thickness of the dynamic release structure 414, releasing the individual components 110 from the tape. A protective film (not shown) may be placed over the adhesive die-capture film 404 before use of the tape 400 to receive the individual components. Incorporation of the dynamic release structure 414 into the tape 400 makes the tape 400 versatile, allowing subsequent laser transfer operations to be performed easily, quickly, and inexpensively, for example.

[0100] Figure 5 shows an example of a tape 500 for receiving individual components in a laser-assisted transfer process. The tape 500 comprises a flexible polymer substrate 502 and an adhesive die-capturing film 504 on the front surface 506 of the tape, the adhesive die-capturing film 504 including a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material. An adhesive layer 508 is located on the rear surface 510 of the flexible polymer substrate 502. For the laser-assisted transfer process of individual components 110 to the tape 500, the tape 500 is attached to a substrate 512 such as a rigid substrate (e.g., a glass, silicon, metal, ceramic, or rigid polymer substrate) by the adhesive layer 508 on the rear surface 510 of the flexible polymer substrate 502. Before the tape 500 is attached to the rigid substrate 512, a protective film (not shown), such as a removable release liner, may be placed over the post-adhesive layer 508 to protect the adhesive layer, for example, to prevent the adhesive layer from adhering to an object or to prevent the adhesive layer from being exposed to the environment.

[0101] Figure 6A shows an example of a tape 600 for receiving individual components in a laser-assisted transfer process. The tape 600 comprises an adhesive die-capture film 604 containing a viscoelastic or viscoplastic adhesive material, or an elastic adhesive material. A pre-protective film 640 is placed on the front surface 606 of the adhesive die-capture film 604. A flexible polymer substrate 602 forms a post-protective film placed on the rear surface 610 of the adhesive die-capture film 604. The protective film 640 and the flexible polymer substrate 602 are self-supporting flexible films, such as release liners having low interfacial adhesion and non-stick properties, respectively. The protective film 640 and the flexible polymer substrate 602 may have properties such as low permeability, moisture protection, ultraviolet (UV) light protection, or other properties that can help prevent degradation of the adhesive die-capture film 604, which may result from, for example, exposure to the environment. The tape 600 comprising the adhesive die-capture film 604, the protective film 640, and the flexible polymer substrate 602 is a self-supporting tape.

[0102] Referring to Figure 6B, in the laser-assisted transfer process, the protective film, which is the flexible polymer substrate 602, is removed from the adhesive die-capture film 604 in order to use the tape 600 to receive the individual components 110, leaving the adhesive die-capture film 604 intact and exposing its rear surface 610. The rear surface 610 of the die-capture film 604 is adhesive because it is formed from an adhesive material such as an elastic adhesive material, a viscoelastic adhesive material, or a viscoplastic adhesive material. The adhesive die-capture film 604 is attached to a substrate 612, such as a rigid substrate, by bringing the rear surface 610 of the adhesive die-capture film 604 into contact with the substrate 612.

[0103] Referring to Figure 6C, the pre-protective film 640 is then removed, leaving the adhesive die-capture film 604 intact and exposing the front surface 606 of the adhesive die-capture film 604. When the individual components 110 are transferred by the laser-assisted transfer process, the individual components are received onto the front surface 606 of the adhesive die-capture film 604, which is directly positioned on the substrate 612.

[0104] Figure 7 shows an example of a self-supporting tape 700. The tape 700 comprises a flexible polymer substrate 702 on which a film 704 is arranged. The film 704 may be a single-layer or multi-layer structure. The film 704 serves as both an adhesive die-capture film and a dynamic release structure. For example, the film 704 may be a single layer of a material (e.g., a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material) with a uniform composition having the properties of an adhesive die-capture film, and also undergoing structural, phase, or chemical changes when irradiated with light (e.g., absorbing incident light, thereby generating an expanding gas and forming a blister within the film 704). The tape 700 can act as a substrate for receiving individual components 110 to be transferred in a laser-assisted transfer process, as previously described. When the individual components 110 are transferred to the tape 700, the film 704 receives and holds the individual components 110, for example, as previously described for an adhesive die-capture film. In one example, a protective film (not shown) is placed on film 704 and removed before the transfer of the components.

[0105] Next, the tape 700 to which the individual components are attached can be used as a source tape in a subsequent laser-assisted transfer process to transfer the individual components 110 to another substrate. For example, an optical system may be used to illuminate the rear surface 710 of the flexible polymer substrate 702. The flexible polymer substrate 702 is transparent to the wavelength of incident light so that light passes through the flexible polymer substrate and enters the region of the film 704. The film 704 undergoes a structural change, phase change, or chemical change in at least a portion of the irradiated region, releasing the individual components 110 from the tape 700. For example, the film 704 is formed from or includes a material configured to absorb incident light, resulting in gas generation and blister formation in the material.

[0106] Figure 8A shows an example of tape 800. Tape 800 comprises a flexible polymer substrate 802 with an adhesive die-capturing film 804 positioned on the front surface 806 of the substrate 802. A dynamic release structure 814 is positioned on the rear surface 810 of the substrate 802. Tape 800 can act as a substrate for receiving individual components 110 to be transferred in a laser-assisted transfer process, as previously described. The adhesive die-capturing film 804 is a viscoelastic adhesive material, a viscoplastic adhesive material, or an elastic adhesive material. When the individual components 110 are transferred to tape 800, the adhesive die-capturing film 804 accepts and holds the individual components 110. In one example, a protective film (not shown) is positioned on the adhesive die-capturing film and removed before the transfer of the components.

[0107] Referring to Figure 8B, the tape 800 with the individual components attached can be used as a source tape in a subsequent laser-assisted transfer process to transfer the individual components 110 to the target substrate 820. The tape 800 is bonded to the support 812 with the dynamic release structure 814 attached to the rigid support 812. The rigid support 812 is held by the individual component support fixture 850, and the back side of the support 812 is illuminated with light from the light source 862, as previously considered in Figure 1. Both the support 812 and the flexible polymer substrate 802 are transparent to the wavelength of incident light so that light passes through the support 812 and the polymer substrate 802 and enters the region of the dynamic release structure 814. The illumination causes a change in the dynamic release structure 814 that releases the individual component 110 from the tape 800. The individual component 110 is moved away from the support 812 and lands on the target substrate 820.

[0108] Die-capturing tapes, such as those described herein, may have advantages over other die-capturing substrates, such as rigid substrates having dies that capture the fluid or gel being placed on them. For example, adhesive die-capturing films can be applied quickly, easily, and inexpensively to other substrates, such as rigid substrates, by, for example, removing a post-protective film and applying the adhesive die-capturing film to the rigid substrate. Adhesive die-capturing films can also be removed quickly, easily, and inexpensively from other substrates, such as rigid substrates, by, for example, peeling the film off the substrate.

[0109] Specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions proposed in the claims may be performed in a different order and still achieve the desired results. As one example, the steps depicted in the accompanying figures do not necessarily require the specific order or sequential order shown to achieve the desired results. In particular embodiments, simultaneous work and parallel processing may be advantageous. [Explanation of Symbols]

[0110] 100 tapes 102 Flexible polymer substrate 104 Adhesive die-capturing film, adhesive coating 106 Front 110 Individual Components 112 Support 114 Dynamic release structure 115 Individual component assembly 116 Bottom side 118 Top surface 120 Top 130 Vacuum Chuck 132 Rear 140 Protective film 150 Individual component support and fixing device 152 gaps 160 Optical system 162 Light source 164 Optical elements 400 tapes 402 Flexible polymer substrate 404 Adhesive Die Capture Membrane 414 Dynamic Release Structure 416 Rear 500 Tapes 502 Flexible polymer substrate 504 Adhesive Die Capture Film 506 Tape front 508 Adhesive layer 510 Rear 512 Rigid substrate 600 Tapes 602 Flexible polymer substrate, post-protective film 604 Adhesive Die Capture Membrane 610 Rear 612 circuit board 640 Front protective film 700 Tapes 702 Flexible polymer substrate 704 Membrane 710 Rear 800 Tapes 802 Flexible polymer substrate 804 Adhesive Die Capture Membrane 806 Front 810 Rear 812 Rigid support 814 Dynamic Release Structure 820 Target substrate 850 Individual component support and fixing device 862 light source

Claims

1. A tape for receiving individual components transferred by a laser-assisted transfer process, wherein the tape is Flexible polymer substrate, A dynamic release structure disposed on the flexible polymer substrate, and An adhesive die-capturing film disposed in the dynamic release structure, comprising an adhesive die-capturing film configured to accept the individual components via the laser-assisted transfer process, The tape is configured to be used during a subsequent laser-assisted transfer process for transferring the individual components to another substrate.

2. The tape according to claim 1, wherein the adhesive die-capturing film comprises one or more of a viscoelastic adhesive material and an elastic adhesive material.

3. The tape according to claim 1, wherein the dynamic release structure is configured to undergo a structural change, phase change, or chemical change in response to irradiation of the dynamic release structure.

4. The tape according to claim 1, wherein the dynamic release structure is configured to form a blister in response to absorbing incident radiation.

5. A tape for receiving individual components transferred by a laser-assisted transfer process, wherein the tape is Flexible polymer substrate, An adhesive die-capturing film disposed on a first surface of the flexible polymer substrate, configured to accept the individual components via the laser-assisted transfer process, and The flexible polymer substrate comprises a dynamic release structure disposed on the second surface, The tape is configured to be used during a subsequent laser-assisted transfer process for transferring the individual components to another substrate.

6. The tape according to claim 5, wherein the adhesive die-capturing film comprises one or more of a viscoelastic adhesive material and an elastic adhesive material.

7. The tape according to claim 5, wherein the dynamic release structure is configured to undergo a structural change, phase change, or chemical change in response to irradiation of the dynamic release structure.

8. The tape according to claim 5, wherein the dynamic release structure is configured to form a blister in response to absorbing incident radiation.

9. A tape for receiving individual components transferred by a laser-assisted transfer process, wherein the tape is Flexible polymer substrates, and A tape comprising a film disposed on the flexible polymer substrate, comprising one or more viscoelastic adhesive materials and elastic adhesive materials, configured to accept and hold the individual components via the laser-assisted transfer process, and configured to undergo structural changes, phase changes, or chemical changes in response to irradiation of the film during a subsequent laser-assisted transfer process for transferring the individual components to another substrate.

10. The tape according to claim 9, wherein the film is configured to form a blister in response to absorbing incident radiation.

11. The tape according to claim 9, wherein the film is a single layer of material having a uniform composition.

12. The tape according to claim 9, wherein the membrane is configured to function as an adhesive die-capturing membrane and a dynamic release structure.

13. A tape for receiving individual components transferred by a laser-assisted transfer process, wherein the tape is Flexible polymer substrate, An adhesive die-capturing film disposed on the flexible polymer substrate, comprising one or more viscoelastic adhesive materials and elastic adhesive materials, and configured to accept the individual components via the laser-assisted transfer process, and The adhesive die capture film includes a protective film disposed on the adhesive die capture film, The adhesive die-capture film is configured to undergo a structural change, phase change, or chemical change in response to irradiation during a subsequent laser-assisted transfer process for transferring the individual components to another substrate, in a tape.

14. The tape according to claim 13, wherein the adhesive die-capturing film comprises a pressure-sensitive adhesive.

15. The tape according to claim 13, wherein the adhesive die-capturing film comprises a viscoelastic material.

16. The tape according to claim 13, wherein the adhesive die-capturing film comprises a crosslinking promoter.

17. The tape according to claim 16, wherein the crosslinking accelerator comprises a photosensitive polymer.

18. The tape according to claim 16, wherein the crosslinking accelerator comprises a chemical catalyst.

19. The tape according to claim 13, wherein the adhesive die-capturing film is disposed on the front surface of the flexible polymer substrate, and the rear surface of the flexible polymer substrate contains an adhesive material.

20. The tape according to claim 19, comprising a rigid substrate, wherein the flexible polymer substrate is attached to the rigid substrate by the adhesive material.

21. The tape according to claim 13, wherein the tape includes a dynamic release structure disposed on the flexible polymer substrate, and the adhesive die-capturing film is disposed on the dynamic release structure.

22. The tape according to claim 13, wherein the flexible polymer substrate is removable from the adhesive die-capture film.

23. The tape according to claim 13, wherein the protective film is removable from the adhesive die-capturing film.

24. The tape according to claim 13, wherein the adhesive die-capture film comprises a die-capture material and is configured to be reused in a plurality of laser-assisted transfer processes.

25. The tape according to claim 13, wherein the adhesive die-capturing film comprises a die-capturing material, the die-capturing material having adhesive properties that enable the adhesive die-capturing film to accept the individual components transferred onto the tape by the laser-assisted transfer process, and, once accepted, to hold the individual components in substantially the same position and to position the individual components flat on the tape, and the die-capturing material is configured to prevent displacement, bouncing, or tombstone of the individual components.

26. The tape according to claim 13, wherein the adhesive die-capturing film comprises a die-capturing material, and the die-capturing material comprises polydimethylsiloxane (PDMS).

27. A tape for receiving individual components transferred by a laser-assisted transfer process, wherein the tape is A tape comprising an adhesive die-capturing film, the adhesive die-capturing film comprising one or more viscoelastic adhesive materials and elastic adhesive materials, configured to accept the individual components via a laser-assisted transfer process, and configured to undergo a structural change, phase change, or chemical change in response to irradiation for a subsequent laser-assisted transfer process to transfer the individual components to another substrate.

Images