Cleaned packaging substrate and method for manufacturing a cleaned packaging substrate

Abstract

The present invention provides a method for manufacturing a cleaned packaging substrate, wherein in a preparation step, a target substrate is placed in a chamber, and in a removal step, ionized air is sprayed onto at least one surface of the target substrate to separate particulate impurities, thereby obtaining a cleaned packaging substrate, the target substrate being at least one of a glass packaging substrate and a packaging substrate, and the packaging substrate includes the glass packaging substrate and a redistribution layer disposed on at least one surface of the glass packaging substrate.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 242,619, filed on September 10, 2021, the entire disclosure of which is incorporated herein by reference for all purposes.

[0002] This disclosure relates to a cleaned packaging substrate and a method for manufacturing a cleaned packaging substrate.

Background Art

[0003] In the manufacture of electronic components, implementing circuits on a semiconductor wafer is called the front - end process (FE), and assembling the wafer so that it can be actually used in a product is called the back - end process (BE). The back - end process may include a packaging process.

[0004] In recent years, the four core technologies of the semiconductor industry that have enabled the rapid development of electronic products are semiconductor technology, semiconductor packaging technology, manufacturing process technology, and software technology. Semiconductor technology has developed into various forms such as line widths in sub - micron to nano units, tens of millions of cells, high - speed operation, and a large amount of heat dissipation. However, relatively, there is no technology that perfectly supports packaging it. Thus, it is considered that the electrical performance of a packaged semiconductor may be determined by packaging technology and the electrical connections thereby, rather than the performance of the semiconductor itself.

[0005] As an example, a glass substrate can be applied as a packaging substrate. By forming through - vias in the glass substrate and applying a conductive material in the through - vias, the length of the conductive line between the element and the motherboard can be shortened, and excellent electrical characteristics can be realized.

[0006] When forming fine through - vias in a glass substrate or making connections for a redistribution layer, a strict cleaning process is essential. Especially when performing fine wiring, impurities such as dust are very important. [Overview of the project]

[0007] This summary is provided to simplify and introduce some of the concepts described later in the detailed description of the invention. This summary is not intended to identify any important or essential features of the claims, nor is it intended to be used as an aid in determining the scope of the claims.

[0008] The present invention provides a method for manufacturing a cleaned packaging substrate, characterized in that, in a preparation step, a target substrate is placed in a chamber, and in a removal step, ionized air is sprayed onto at least one surface of the target substrate to separate particulate impurities and obtain a cleaned packaging substrate, the target substrate is at least one of a glass packaging substrate and a packaging substrate, and the packaging substrate comprises a redistribution layer disposed on at least one surface of the glass packaging substrate and the glass packaging substrate.

[0009] The removal process is configured to suppress the generation of static electricity by irradiating the target substrate with soft X-rays and ionized air.

[0010] The atmosphere in the chamber during the removal process has an airflow in which a force is applied in the opposite direction to the direction of gravity.

[0011] The ionized air injected in the removal process is either an inert gas or dry air.

[0012] The residual charge potential of the substrate in the removal process is 0V.

[0013] The space inside the chamber during the removal process is maintained at a low pressure atmosphere of 0.9 atmospheres or less.

[0014] The ionized air in the removal step is sprayed toward one of the first surface and the second surface of the substrate, and the air flows at an angle of 30 to 150 degrees relative to the first surface of the substrate.

[0015] The glass packaging substrate is provided with through vias that penetrate in the thickness direction, and the through vias have openings with a maximum length of 300 μm or less.

[0016] The redistribution layer of the packaging substrate comprises blind vias, and the blind vias have openings with a maximum length of 20 μm or less.

[0017] Other features and embodiments will become apparent from the following detailed description, drawings, and claims. [Modes for carrying out the invention]

[0018] The following detailed descriptions are provided to assist readers in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various modifications, alterations, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the sequence of operations described herein is merely illustrative and not limited to those described herein, and may be modified as will become apparent upon understanding this disclosure, unless the operations must necessarily be performed in a specific order. Furthermore, while descriptions of publicly known features may be omitted for clarity and conciseness, it should be noted that the omission of features and their descriptions are not intended to imply any assumption of general knowledge.

[0019] The features described herein can be embodied in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided merely to illustrate some of the many possible ways of realizing the methods, apparatus, and / or systems described herein, which will become apparent after understanding this disclosure.

[0020] In this specification, terms such as “first,” “second,” and “third” are used to describe various members, components, regions, layers, or sections, but these members, components, regions, layers, or sections are not limited. Rather, these terms are used solely to distinguish one member, component, region, layer, or section from another. Accordingly, a first member, component, region, layer, or section referred to in the examples described herein may also be referred to as a second member, component, region, layer, or section without departing from the teaching of the examples.

[0021] In the specification, when an element such as a layer, region, or substrate is described as being "on top of" another element, or "connected" to or "joined" to another element, it means that it is directly "on top of," "connected to," or "joined" to another element, or that one or more other elements are interposed between them. On the other hand, when an element is described as being "directly on top of," "directly connected to," or "directly joined" to another element, there are no other elements interposed between them. Similarly, expressions such as "between," "immediately between," "adjacent to," and "immediately adjacent to" can also be interpreted in the manner described above.

[0022] The terms used herein are for illustrative purposes only and are not intended to limit this disclosure. The singular form used herein is intended to include the plural form unless the context explicitly indicates otherwise. The terms “and / or” used herein include any one of the relevant enumerated items and any combination of any two or more items. The terms “include,” “equip,” and “have” used herein identify the presence of a described feature, number, operation, element, component, and / or combination thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, elements, components, and / or combination thereof. In this specification, the term “may also” in an example or embodiment (for example, with respect to what an example or embodiment may include or be able to implement) means that there is at least one example or embodiment that includes or implements such features; however, not all examples are limited to this.

[0023] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by a person ordinary in the art to which this disclosure belongs, consistently after understanding this disclosure. Terms as defined in commonly used dictionaries shall be construed to have the meaning consistent with their meaning in the context of the relevant technology and this disclosure, and should not be construed in an idealized or overly formal sense unless expressly defined herein.

[0024] In this specification, "A and / or B" means "A, B, or A and B".

[0025] In this specification, terms such as "First," "Second," or "A," "B" are used to distinguish between identical terms unless otherwise specified.

[0026] One or more embodiments provide a method for manufacturing a cleaned packaging substrate and a cleaned packaging substrate.

[0027] In one or more embodiments, a method for manufacturing a cleaned packaging substrate and the cleaned packaging substrate can minimize damage to the substrate that may occur due to the influence of static electricity in the cleaning process, and can efficiently remove impurities from a substrate having a complex structure or small holes.

[0028] In one or more embodiments, a singular expression is construed in context to include plural and singular forms unless otherwise explained.

[0029] In a package substrate of a high-performance semiconductor device, it may be desirable to regulate the difference in wiring scale between a boat at the lower end of the substrate and an element at the upper end of the substrate. To achieve this, a process of applying two or more layers of prepreg, a process of making the prepreg and the silicon substrate into two layers, etc. were applied. This is because the difference in wiring scale between a board disposed at the lower end of the packaging substrate and an element disposed at the upper end of the packaging substrate can be regulated relatively easily through two layers of substrates. However, in such a method, it is difficult to meet the requirement of thinning in the packaging of semiconductor devices.

[0030] A package substrate of a high-performance semiconductor device may apply one layer of glass substrate as a support layer. Therefore, it may be desirable to arrange lines and vias having various sizes inside one package substrate. Precise impurity control is desired to realize the application of a rewiring layer as a fine layer, the reduction of the via size, and the implementation of a complex wiring pattern in a small area of the package substrate. Therefore, the importance of the cleaning process is increasing in the manufacturing process of the package substrate.

[0031] Glass substrates can be used as the core of packaging substrates. Using stress-controlled glass substrates for semiconductor packaging allows for the creation of thinner, finer lines. However, glass substrates are susceptible to impact forces and unbalanced stresses. Using prepregs, manufactured by impregnating glass fibers with polymers, can strengthen the glass substrate. Therefore, if an energy imbalance occurs within the glass substrate, the substrate itself may break, potentially requiring extensive cleaning of the entire process chamber.

[0032] Therefore, in glass substrates or packaging substrates using glass substrates as cores, it is necessary to apply a cleaning method that efficiently removes impurities and suppresses the generation of unbalanced stress and impact.

[0033] The following describes the examples in detail.

[0034] The method for manufacturing a cleaned packaging substrate is applied to the manufacturing process of a glass substrate or a packaging substrate comprising the same, and includes a preparation step and a removal step.

[0035] The aforementioned preparation step is the step of placing the target substrate inside the chamber.

[0036] Placing the target substrate means fixing it in a predetermined position so that it does not separate due to interaction with elements such as air jets, but it is not limited to air jets.

[0037] The fixing step may involve placing the target substrate in a rack provided inside the chamber. The fixing step may also involve placing the target substrate in a multi-layer rack provided inside the chamber.

[0038] The removal step involves spraying ionized air onto at least one surface of the target substrate to separate particulate impurities, thereby producing a cleaned substrate for packaging.

[0039] The aforementioned substrate is a glass packaging substrate or a packaging substrate.

[0040] The glass packaging substrate may be a semiconductor glass substrate, for example, a borosilicate glass substrate, an alkali-free glass substrate, or the like.

[0041] The glass packaging substrate may have through vias that penetrate in the thickness direction. The through vias may have openings with a maximum length of about 300 μm or less. The through vias may have an aspect ratio which is the ratio of the maximum length of the opening to the height of the through via (corresponding to the thickness of the glass substrate), which is about 0.5 to about 1.5.

[0042] If the through via has a narrow opening or a large aspect ratio, a more thorough removal process is necessary to ensure that the inside of the via is thoroughly cleaned.

[0043] The glass substrate may have a cavity in which part or all of its thickness is recessed.

[0044] The aforementioned removal process can effectively remove impurities not only from the surface of the glass substrate, but also from the inside of vias, the sides and bottom of cavities, and other areas.

[0045] The packaging substrate may include a glass packaging substrate and a redistribution layer disposed on at least one surface of the glass packaging substrate.

[0046] The redistribution layer may be arranged on one surface of the glass packaging substrate.

[0047] The redistribution layer may be arranged on the first and second surfaces of the glass packaging substrate, respectively.

[0048] The redistribution layer of the packaging substrate may include blind vias.

[0049] The blind via may have an opening having a maximum length of approximately 20 μm or less, or approximately 12 μm or less.

[0050] The redistribution layer, which is disposed on the first surface of the glass packaging substrate, may be connected to the second surface of the glass packaging substrate via the core of the glass substrate. The second surface may be connected to an external element via a buff or similar device. The second surface may be connected to an external element via a buff or similar device disposed on the second surface.

[0051] The redistribution layer may include an electrically conductive layer as a fine layer. The fine layer refers to an electrically conductive layer with a width of approximately 4 μm or less. Specifically, it may be an electrically conductive layer applied such that the width and spacing are each approximately 4 μm or less, or approximately 1 μm to approximately 4 μm.

[0052] The thickness of the target substrate may be approximately 1,500 μm or less, approximately 300 μm to approximately 1,200 μm, 350 μm to 900 μm, or 350 μm to 700 μm.

[0053] The redistribution layer may be formed through a multi-step process involving repeated formation of an insulating layer, via formation, plating, etching, etc. A cleaning step is necessary at each stage, including via formation, insulating layer formation, subsequent planarization, plating, and removal of unwanted impurities after etching.

[0054] In such processes, if even a small amount of impurities such as dust are present, defects such as bridge defects, open defects, and etching defects may occur. To prevent this, the removal process must thoroughly remove impurities regardless of the complex morphology of the substrate surface or differences in the substrate surface material.

[0055] In particular, packaging glass substrates are made of insulating material, and damage such as glass cracking or shattering can occur. Therefore, the inside of the chamber needs to be cleaned. Damage can also occur to the glass substrate itself. Furthermore, if an imbalance of charge occurs within the glass substrate above a certain level, the glass substrate itself may crack. Therefore, in addition to controlling impact during the process, control of ions and static electricity during the cleaning process is also desirable.

[0056] The aforementioned removal process involves spraying ionized air onto the target substrate to separate particulate impurities.

[0057] The aforementioned air injection may be performed by a nozzle.

[0058] The injected air may be applied by a method of injecting ionized air, or the air may be treated to be ionized on the surface of the substrate after injection.

[0059] The injected air may be an inert gas or dry air.

[0060] The aforementioned inert gas may be nitrogen gas, argon gas, or the like, but is not limited to these.

[0061] The air injection in the removal process may be performed on the first surface of the substrate or the second surface of the substrate.

[0062] The air may flow at an angle of approximately 30 to 150 degrees relative to the first surface of the substrate. The air may also flow at an angle of approximately 30 to 85 degrees, or approximately 95 to 150 degrees. The air inflow angle may be estimated by the nozzle angle.

[0063] In removing impurities from the substrate surface, it is important to separate the impurities from the surface using air. Furthermore, it is also important to control the process so that the separated impurities do not reattach to the substrate surface.

[0064] Air jets can cause static electricity and charge imbalances on the surface of the substrate, and this tends to be more severe if the substrate is an insulator.

[0065] By applying methods to control the airflow within the chamber and / or by spraying ionized air and irradiating it with ultraviolet light, it is possible to suppress the generation of static electricity, which does not substantially damage the substrate, and also to efficiently remove impurities.

[0066] Controlling the airflow within the chamber means creating an airflow that acts in the opposite direction to gravity. Preferably, turbulence may be partially formed. When turbulence is applied as the airflow within the chamber, impurities separated by the injected air move through the chamber with the turbulent flow and are efficiently removed, and the re-adhesion of impurities to the substrate can be suppressed.

[0067] The space inside the chamber during the removal process may be maintained at a low pressure of 0.9 atmospheres or less.

[0068] The removal process may be carried out while irradiating the target substrate with soft X-rays to suppress the generation of static electricity.

[0069] Various methods can be applied to suppress the generation of static electricity.

[0070] Possible methods include soft X-rays, electromagnetic wave ionizers, UV lamps, and atmospheric pressure plasma. In one or more embodiments, soft X-rays may be applied.

[0071] Electrostatic discharge suppression using soft X-rays works by forming ions or electrons through the electrolytic dissociation of air molecules near the target substrate, thereby suppressing static electricity on the substrate surface. Since a light irradiation method can be applied, it has the advantage of not requiring the addition of ion-transmitting equipment like that used in plasma methods. Furthermore, even when irradiated in an oxygen-containing atmosphere, virtually no ozone is generated, making it more advantageous than using ultraviolet lamps.

[0072] The soft X-rays may be light with wavelengths of approximately 1 angstrom to approximately 700 angstroms, or approximately 1 angstrom to approximately 10 angstroms. The electrolytic dissociation energy may be approximately 10 keV or less, or approximately 1 keV to approximately 10 keV. The soft X-rays are applied from approximately 50 cm away from the target substrate. within Alternatively, the light may be irradiated from a distance of approximately 2 cm to 30 cm. In such cases, static electricity can be controlled more effectively.

[0073] The removal step may have a residual charge potential that is substantially about 0V. In this example, the re-adhesion of impurities due to static electricity can be suppressed, and damage to the substrate caused by ionization or static electricity can be reliably prevented.

[0074] The manufacturing method for cleaned packaging substrates allows for reliable removal of foreign matter from the substrate without substantial damage or deformation to the substrate itself. Furthermore, it can be stably and efficiently applied to highly insulating materials such as glass substrates.

[0075] In another embodiment, the method for manufacturing a packaging substrate may include the steps of preparing a glass substrate, forming an electrically conductive layer on the substrate, forming an insulating layer, forming an electrically conductive layer, cleaning, and inspection.

[0076] The step of preparing the glass substrate is the step of preparing a glass substrate to be applied to semiconductor packaging. This glass substrate is in the form of a thin plate and may optionally have cavities and / or vias. The cavity means a part of the glass substrate that is recessed, and the recessed part may penetrate the glass substrate or may not penetrate the glass substrate and a part of it may remain.

[0077] The step of preparing the glass substrate involves preparing a cleaned glass substrate or a glass substrate from which static electricity has been removed. Further cleaning or static electricity removal steps may be performed before proceeding to the subsequent steps.

[0078] In one example, the cleaning step may be the removal step described above, and the removal of static electricity may be, for example, the step using soft X-rays described above, and these steps may be performed simultaneously or sequentially.

[0079] The step of forming an electrically conductive layer on a substrate is to form an electrically conductive layer on the surface of the glass substrate in a predetermined pattern.

[0080] The glass substrate may have vias or cavities, and the electrically conductive layer may be formed inside the vias and on the walls of the cavities.

[0081] The electrically conductive layer may be formed by, for example, plating or sputtering to form a copper layer or a copper alloy layer. For example, an electrically conductive layer of a desired shape and thickness may be formed by forming a primer layer at a predetermined position, forming an insulating layer, and then partially removing the portion to be formed of the electrically conductive layer and performing copper plating. If necessary, the copper plated layer may be planarized.

[0082] The step of forming an insulating layer is to form an insulating layer to be interposed between electrically conductive layers, and can be carried out by curing a polymer resin containing nanoparticles. Preferably, the insulating layer has a flattened surface (top surface).

[0083] The step of forming an electrically conductive layer is to form the electrically conductive layer at a predetermined position on the insulating layer. The formation of the electrically conductive layer may be carried out by methods such as plating or sputtering to form a copper layer or a copper alloy layer. For example, an electrically conductive layer of a desired shape and thickness may be formed by forming a primer layer at a predetermined position, forming an insulating layer, and then partially removing the portion to be formed of the electrically conductive layer and performing copper plating. Planarization of the copper plated layer may be performed as needed.

[0084] The cleaning step is the cleaning step described above, and may include removing dust and static electricity by airflow.

[0085] The inspection step is to verify whether there are any defects in the substrate or wires, and whether any impurities generated during the process have been completely removed. The process is carried out using specialized testing equipment, and any packaging substrates that fail the test based on the testing equipment's inspection step may be subjected to the cleaning step again or discarded.

[0086] The steps of forming the insulating layer and forming the electrically conductive layer may further optionally include steps of forming vias and cleaning.

[0087] The steps of forming an insulating layer and forming an electrically conductive layer may further selectively include steps of forming vias, forming via electrically conductive layers, and cleaning.

[0088] The steps of forming the insulating layer and forming the electrically conductive layer may further optionally include steps of forming vias, cleaning, and forming via electrically conductive layers and cleaning.

[0089] In the step of forming vias, vias may be formed to connect electrically conductive layers arranged in an upper and lower position. For example, the vias may be formed by etching a portion of the insulating layer at a predetermined location and size. For example, laser etching, plasma etching, etc., can be applied. After etching, the process may optionally further include steps of removing etching residue and confirming whether the etching residue has been removed.

[0090] The step of forming a via electrical conductive layer is the step of forming an electrical conductive layer on the via. The electrical conductive layer may be formed along the surface of the inner diameter of the via with a relatively constant thickness. The electrical conductive layer may be formed in such a manner that it fills the entire via. The formation of the electrical conductive layer is the same as the electrical conductive layer formation process described above, so no further explanation is given.

[0091] The steps of forming the insulating layer and forming the electrically conductive layer may be repeated multiple times as necessary. Furthermore, any additional steps between the steps of forming the insulating layer and forming the electrically conductive layer may be repeated as necessary.

[0092] Since the explanation of each step overlaps with the explanation above, further explanation will be omitted.

[0093] In one example, the glass substrate may be a glass substrate having a cavity structure.

[0094] The steps of forming an electrically conductive layer on a substrate and forming an insulating layer may optionally include a step of placing elements (referred to as cavity elements in the sense that they are placed inside the cavity) in a cavity or the like.

[0095] The cavity element may be a capacitor such as an MLCC, but is not limited to this.

[0096] The step of placing elements in a cavity or the like may include the steps of placing cavity elements in predetermined positions and forming insulating layers, electrically conductive layers, insulating layers, etc., in predetermined positions.

[0097] The process may further include a step of attaching solder balls before or after the inspection step.

[0098] The step of attaching solder balls is the step of attaching solder balls to the top and / or bottom surfaces of the circuit board.

[0099] The aforementioned solder ball may be formed by directly connecting the package substrate and the external element, or it may be done as described in the following steps.

[0100] The following steps may be sequentially applied: preparing a pad at the position where solder balls will be formed; opening the top surface of the pad to form an insulating film on one side of the substrate; and providing a metal masking layer on the top surface of the pad and placing a buff and metal balls thereon.

[0101] The pad may be, for example, aluminum, but is not limited thereto. The metal masking layer may be, for example, one or more layers of copper alloy, titanium, etc., but is not limited thereto. The metal ball may be, for example, a tin ball, but is not limited thereto.

[0102] The manufacturing method for packaging substrates not only avoids significant damage or deformation to the substrate itself, but also allows for highly reliable removal of impurities from the target substrate. Furthermore, it can be stably and efficiently applied to glass substrates and other materials that act as high insulators.

[0103] One or more packaging substrates according to the embodiment may be cleaned by the method described above. Cleaned packaging substrates can effectively suppress bridge defects, open defects, etching defects, etc., and provide packaging substrates with improved reliability.

[0104] This disclosure includes specific embodiments, but it will be apparent to those skilled in the art, after understanding the disclosure, that various modifications in form and detail can be made in these embodiments without departing from the spirit and scope of the claims and their equivalents. The embodiments described herein should be considered for illustrative purposes only and not as limiting. The descriptions of features or embodiments in each embodiment should be considered applicable to similar features or embodiments in other embodiments. If the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are combined in different ways, and / or replaced or supplemented by other components or their equivalents, suitable results may be achieved. Accordingly, the scope of this disclosure is defined by the claims and their equivalents, not by the detailed description, and all modifications within the scope of the claims and their equivalents should be construed as being included in this disclosure.

[0105] Therefore, the scope of this disclosure is defined by the claims and their equivalents, rather than by a detailed description, and all variations within the scope of the claims and their equivalents should be interpreted accordingly.

Claims

1. A method for manufacturing a cleaned packaging substrate, In the preparation process, the target substrate is placed inside the chamber. In the removal process, in order to separate particulate impurities, ionized air is sprayed onto at least one surface of the target substrate to obtain a cleaned packaging substrate. The aforementioned target substrate is at least one of a glass packaging substrate and a packaging substrate. The packaging substrate comprises the glass packaging substrate and a redistribution layer disposed on at least one surface of the glass packaging substrate. The atmosphere in the chamber during the removal process has an airflow in which a force is applied in the opposite direction to the direction of gravity. The removal step is configured to suppress the generation of static electricity due to ionized air by irradiating the target substrate with soft X-rays, and the soft X-rays having a wavelength of 1 angstrom to 700 angstroms are irradiated at a distance of 50 cm or less from the target substrate, characterized in that the manufacturing method.

2. The manufacturing method according to claim 1, wherein the ionized air sprayed in the removal step is one of an inert gas and dry air.

3. The manufacturing method according to claim 1, characterized in that the residual charge potential of the substrate in the removal step is 0V.

4. The manufacturing method according to claim 1, wherein the space inside the chamber during the removal step is maintained in a low-pressure atmosphere of 0.9 atmospheres or less.

5. The injection of ionized air in the removal step is performed on one of the first surface and the second surface of the substrate. The manufacturing method according to claim 1, wherein the air flows at an angle of 30 to 150 degrees with respect to the first surface of the substrate.

6. The glass packaging substrate is provided with through vias that penetrate in the thickness direction, The manufacturing method according to claim 1, wherein the through via has an opening with a maximum length of 300 μm or less.

7. The redistribution layer of the packaging substrate comprises blind vias, The manufacturing method according to claim 1, characterized in that the blind via has an opening with a maximum length of 20 μm or less.