Package substrate and manufacturing method thereof

Abstract

The invention provides a packaging substrate and a manufacturing method thereof, the packaging substrate comprises at least two glass substrates which are stacked in sequence, each glass substrate is provided with at least one conductive circuit pattern layer, and a part of each conductive circuit pattern layer is exposed to one of two opposite surfaces of the glass substrate; the opposite surfaces of at least one pair of adjacent glass substrates comprise a bonding connection area of glass, a bonding connection area of the conductive circuit pattern layer and a bonding connection area of the glass and the conductive circuit pattern layer. According to the invention, the problem of substrate connection reliability caused by micro-cracks, layering and the like generated in the manufacturing process and the use process of the packaging substrate in the prior art can be solved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor packaging technology, and in particular to a packaging substrate and a manufacturing method thereof. Background Art

[0002] Packaging technology involves placing an integrated circuit die on a substrate, which acts as a support. The substrate and die are then fixedly interconnected to form a complete package, with pins extending from the package. The package provides chip protection, electrical interconnection, and heat dissipation. Glass, as an emerging core material for package substrates, offers advantages such as a thermal expansion coefficient more compatible with silicon, a higher glass transition temperature, a higher Young's modulus, improved flatness, and superior thermal and mechanical stability. Consequently, it has attracted widespread attention from chip designers and package substrate manufacturers.

[0003] Glass substrates are typically separated from the conductive circuit pattern layer by an insulating layer, such as a build-up film (ABF, short for Ajinomoto Build-up Film). Conventional technology typically employs lamination to create the insulating layer on the surface of the glass substrate. However, due to the mismatch in the coefficient of thermal expansion (CTE) between the glass and the insulating layer, microcracks and delamination can occur during the manufacturing process and use of the package substrate, leading to reliability issues with the substrate connection. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art, and proposes a packaging substrate and a manufacturing method thereof, which can solve the problem of substrate connection reliability caused by microcracks, delamination, etc. generated during the manufacturing process and use of the packaging substrate in the related technology.

[0005] To achieve the above objectives, an embodiment of the present application provides a packaging substrate, comprising at least two glass substrates stacked in sequence, each of the glass substrates being provided with at least one conductive circuit pattern layer, and a portion of each conductive circuit pattern layer being exposed on one of two opposing surfaces of the glass substrates;

[0006] The surfaces facing each other of at least one pair of adjacent glass substrates include glass-to-glass bonding areas, bonding areas between the conductive circuit pattern layers and bonding areas between the conductive circuit pattern layers, and bonding areas between the glass and the conductive circuit pattern layers.

[0007] In some embodiments, a groove is formed on at least one of two opposite surfaces of the glass substrate, and the conductive circuit pattern layer is disposed in the groove.

[0008] In some embodiments, one of at least one pair of adjacent glass substrates is a double conductive layer glass substrate, and the other is a single conductive layer glass substrate;

[0009] The double-conductive-layer glass substrate is provided with two layers of the conductive circuit pattern layers, and the two layers of the conductive circuit pattern layers are respectively exposed on two opposite surfaces of the double-conductive-layer glass substrate; the double-conductive-layer glass substrate is provided with at least one first conductive connecting portion, and the two ends of the first conductive connecting portion are respectively interconnected with the two layers of the conductive circuit pattern layers of the double-conductive-layer glass substrate;

[0010] The single conductive layer glass substrate is provided with a conductive circuit pattern layer, the conductive circuit pattern layer being exposed on a surface of the single conductive layer glass substrate away from the double conductive layer glass substrate; the single conductive layer glass substrate is provided with at least one second conductive connection portion, one end of the second conductive connection portion being interconnected with the conductive circuit pattern layer of the single conductive layer glass substrate, and the other end being interconnected with the adjacent conductive circuit pattern layer of the double conductive layer glass substrate;

[0011] The surfaces of the double-conductive-layer glass substrate and the single-conductive-layer glass substrate facing each other include the bonding connection area between glass and glass, the bonding connection area between the conductive circuit pattern layer and the second conductive connection part, and the bonding connection area between glass and the conductive circuit pattern layer.

[0012] In some embodiments, at least one pair of adjacent glass substrates are both single conductive layer glass substrates;

[0013] The surfaces of each single conductive layer glass substrate facing away from each other are respectively a first surface and a second surface, and the first surface of each single conductive layer glass substrate is opposite to the second surface of the adjacent single conductive layer glass substrate;

[0014] Each of the single-conductive-layer glass substrates is provided with a conductive circuit pattern layer, and the conductive circuit pattern layer is exposed on the first surface; each of the single-conductive-layer glass substrates is provided with at least one conductive connecting portion, one end of the conductive connecting portion is interconnected with the conductive circuit pattern layer of the single-conductive-layer glass substrate, and the other end is interconnected with the conductive circuit pattern layer of the adjacent single-conductive-layer glass substrate;

[0015] The first surface of each single conductive layer glass substrate and the second surface of the adjacent single conductive layer glass substrate include a glass-to-glass bonding connection area, a bonding connection area between the conductive circuit pattern layer and the conductive connection part, and a bonding connection area between glass and the conductive circuit pattern layer.

[0016] In some embodiments, the exposed surface of the conductive circuit pattern layer is recessed into the surface of the glass substrate on the same side before the bonding process, and is flush with the surface of the glass substrate on the same side after the bonding process.

[0017] As another technical solution, the present application also provides a method for manufacturing a packaging substrate, comprising:

[0018] Providing at least two glass substrates; each of the glass substrates is provided with at least one conductive circuit pattern layer, and a portion of each conductive circuit pattern layer is exposed on one of two opposing surfaces of the glass substrate;

[0019] performing a bonding process on at least two of all the glass substrates in sequence according to a preset order;

[0020] Wherein, the bonding connection between glass and glass, the bonding connection between the conductive circuit pattern layers and the bonding connection between glass and the conductive circuit pattern layer are completed in one bonding process.

[0021] In some embodiments, before the bonding process is performed, the exposed surface of the conductive circuit pattern layer is recessed into the surface of the glass substrate on the same side;

[0022] During the bonding process, the conductive circuit pattern layer expands due to heat, and after the bonding process, the exposed surface of the conductive circuit pattern layer is flush with the surface of the glass substrate on the same side, so as to achieve bonding connection between the conductive circuit pattern layer and the corresponding conductive circuit pattern layer or glass.

[0023] In some embodiments, before the bonding process, the distance between the exposed surface of the conductive circuit pattern layer and the surface of the glass substrate on the same side is greater than or equal to 1 nm and less than or equal to 3 μm.

[0024] In some embodiments, the bonding process includes:

[0025] Processing a surface of the glass substrate for stacking with other glass substrates to improve surface flatness;

[0026] performing an activation treatment on a surface of the glass substrate for stacking with other glass substrates;

[0027] Performing initial bonding on at least two glass substrates to be bonded at a first temperature;

[0028] The at least two glass substrates to be bonded are bonded at a second temperature; the second temperature is higher than the first temperature.

[0029] In some embodiments, the second temperature is greater than or equal to 200° C. and less than or equal to 800° C.

[0030] In some embodiments, all of the glass substrates include a double conductive layer glass substrate and at least two single conductive layer glass substrates;

[0031] The step of performing a bonding process on at least two of all the glass substrates in a preset order includes:

[0032] performing at least one bonding process;

[0033] In each bonding process, two of the single conductive layer glass substrates are bonded to the double conductive layer glass substrate or the single conductive layer glass substrate on opposite sides of the double conductive layer glass substrate; or, one of the single conductive layer glass substrates is bonded to the double conductive layer glass substrate or the single conductive layer glass substrate on one of the opposite sides of the double conductive layer glass substrate.

[0034] In some embodiments, all of the glass substrates are single conductive layer glass substrates;

[0035] The step of performing a bonding process on at least two of all the glass substrates in a preset order includes:

[0036] performing at least one bonding process;

[0037] In each bonding process, the (i+1)th single conductive layer glass substrate is bonded to the (i)th single conductive layer glass substrate on one side of the (i)th single conductive layer glass substrate, where i=1, 2, ..., N, where N is the total number of the single conductive layer glass substrates, and the remaining single conductive layer glass substrates except the first single conductive layer glass substrate are all located on the same side of the first single conductive layer glass substrate.

[0038] In some embodiments, all of the glass substrates are single conductive layer glass substrates;

[0039] The step of performing a bonding process on at least two of all the glass substrates in a preset order includes:

[0040] performing the bonding process at least twice;

[0041] wherein, in the jth bonding process, one of the single conductive layer glass substrates is bonded to the corresponding single conductive layer glass substrate at one of the first and second sides of the first single conductive layer glass substrate, which are opposite to each other;

[0042] In the kth bonding process, one of the single conductive layer glass substrates is bonded to the corresponding single conductive layer glass substrate on the other of the first and second sides of the first single conductive layer glass substrate, which are opposite to each other;

[0043] Wherein, j is an odd number in the 1st to Mth bonding processes, k is an even number in the 1st to Mth bonding processes, M is the total number of bonding processes, and M=N-1, where N is the total number of the single conductive layer glass substrates.

[0044] In some embodiments, further comprising:

[0045] A chemical etching method is used to perform a cutting process on all the glass substrates after the bonding process is completed.

[0046] Other objects and features of the present application will become clear by reading the specification, claims and drawings of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0048] Figure 1 This is a cross-sectional view of the first packaging substrate provided in an embodiment of the present application.

[0049] Figure 2 This is a cross-sectional view of the second packaging substrate provided in an embodiment of the present application.

[0050] Figure 3 4 is a cross-sectional view of a double-conductive-layer glass substrate provided in an embodiment of the present application.

[0051] Figure 4 4 is a cross-sectional view of a single conductive layer glass substrate provided in an embodiment of the present application.

[0052] Figure 5 This is a flow chart of a method for manufacturing a packaging substrate provided in an embodiment of the present application.

[0053] Figure 6 This is a flow chart of the bonding process of the method for manufacturing a packaging substrate provided in an embodiment of the present application.

[0054] Figure 7a This is a flowchart of step S101 of the method for manufacturing a packaging substrate provided in an embodiment of the present application.

[0055] Figure 7b This is a flowchart of step S102 of the method for manufacturing a packaging substrate provided in an embodiment of the present application.

[0056] Figure 7cThis is a flowchart of step S103 of the method for manufacturing a packaging substrate provided in an embodiment of the present application.

[0057] Figure 7d yes Figure 1 A cross-sectional view of a cored glass substrate after the first bonding process is completed is shown.

[0058] Figure 8 yes Figure 2 The process diagram of the coreless glass substrate undergoing the triple bonding process is shown.

[0059] Figure 9 This is a process diagram of another coreless glass substrate undergoing a triple bonding process. DETAILED DESCRIPTION

[0060] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0061] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0062] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0063] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0064] Throughout this specification, reference to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0065] Please also refer to Figures 1 to 4 An embodiment of the present application provides a packaging substrate 100, comprising at least two glass substrates 1 stacked in sequence, each glass substrate 1 being provided with at least one conductive circuit pattern layer 2, and a portion of each conductive circuit pattern layer 2 being exposed on one of two opposing surfaces of the glass substrate 1; and at least one pair of adjacent glass substrates 1 having opposing surfaces comprising glass-to-glass bonding connection areas, conductive circuit pattern layers 2-to-conductive circuit pattern layers 2 bonding connection areas, and glass-to-conductive circuit pattern layer 2 bonding connection areas.

[0066] Specifically, the glass substrate 1 is made of, for example, silicate glass. Each conductive circuit pattern layer 2 is embedded in the glass substrate 1 and partially exposed on one of the two opposing surfaces of the glass substrate 1. By embedding each conductive circuit pattern layer 2 in the glass substrate 1, a basis for direct bonding between adjacent glass substrates 1 is provided. In some embodiments, at least one of the two opposing surfaces of the glass substrate 1 is formed with a groove, and the conductive circuit pattern layer 2 is disposed in the groove. The groove depth is, for example, 15 μm. This allows the conductive circuit pattern layer 2 to be embedded in the glass substrate 1 and exposed from the groove opening, enabling interconnection with the conductive circuit pattern layer 2 in the other glass substrate 1. Here, two adjacent glass substrates 1 are referred to as a "pair" of glass substrates 1, and at least one pair of glass substrates 1 is connected by bonding. In other words, all adjacent glass substrates 1 can be connected by bonding, or some adjacent glass substrates 1 can be connected by bonding, while other adjacent glass substrates 1 can be connected by other methods, depending on specific needs.

[0067] Because each of the opposing surfaces of a pair of adjacent glass substrates 1 has an exposed conductive circuit pattern layer area and a glass area other than the exposed area, and because at least one of the parameters, such as shape, size, and distribution, of the exposed conductive circuit pattern layer area and the glass area of ​​the adjacent glass substrates 1 differ, three overlapping modes exist for the aforementioned two areas of the pair of adjacent glass substrates 1: the first overlapping mode is where the glass areas of the adjacent glass substrates 1 overlap; the second overlapping mode is where the exposed conductive circuit pattern layer areas of the adjacent glass substrates 1 overlap; and the third overlapping mode is where the glass area of ​​one of the adjacent glass substrates 1 overlaps the exposed conductive circuit pattern layer areas of the other. Based on this, for a pair of adjacent glass substrates 1 bonded together, the opposing surfaces of the two substrates include the glass-to-glass bonded connection area, the conductive circuit pattern layer 2 bonded connection area, and the glass-to-conductive circuit pattern layer 2 bonded connection area. The glass-to-glass bond first forms a preliminary bond at room temperature using intermolecular forces (primarily van der Waals forces) on the glass surface. Then, at elevated temperatures, the thermal motion of atoms or ions in the glass is intensified, causing the atoms or ions on the glass surface to rearrange and combine, forming a stronger covalent bond and further enhancing the bond strength. The conductive circuit pattern layer 2 is bonded to the conductive circuit pattern layer 2 at elevated temperatures, utilizing the fact that the thermal expansion coefficient of the conductive metal (e.g., Cu) is greater than that of the surrounding glass (e.g., 3-10 ppm / °C). This causes the volume of the conductive circuit pattern layer 2 to expand, allowing the exposed surface of the conductive circuit pattern layer 2 to align with the surface of the glass substrate 1 on the same side and contact the corresponding conductive circuit pattern layer 2. During this process, the metal atoms of the two conductive circuit pattern layers 2 diffuse into each other's crystal lattices, thereby achieving a strong bond between the two conductive circuit pattern layers 2. The glass and the conductive circuit pattern layer 2 are bonded by first forming a preliminary bond at room temperature using intermolecular forces such as van der Waals forces between the surfaces of the glass and the conductive circuit pattern layer 2. Then, under high temperature conditions, a chemical reaction or physical change occurs at the interface between the glass and the conductive circuit pattern layer 2, such as by forming some transition compounds or enhancing the bonding force of the interface, thereby achieving a stronger bond between the glass and the conductive circuit pattern layer 2.

[0068] The present application realizes direct bonding between glass substrates 1, that is, in the same bonding process, the bonding of glass to glass, the bonding of conductive circuit pattern layer 2 to conductive circuit pattern layer 2, and the bonding of glass to conductive circuit pattern layer 2 on the surfaces facing each other of a pair of adjacent glass substrates 1 are realized. This bonding method does not have the problems in the prior art such as the inconsistent thermal expansion coefficients of glass and insulating layer, which may cause micro cracks and delamination during the production process and use of the packaging substrate 100, thereby improving the connection reliability. Moreover, the above-mentioned bonding method can freely and flexibly combine glass substrates of different types and quantities. The types of glass substrates 1 include, for example, Figure 4 The single conductive layer glass substrate 1b shown and Figure 3 The double conductive layer glass substrate 1a shown in FIG. 1 and the combination of the single conductive layer glass substrate 1b and the double conductive layer glass substrate 1a are referred to as Figure 1 The core glass substrate 100a shown in FIG. 1 and the combination of the single conductive layer glass substrate 1b are referred to as Figure 2 The coreless glass substrate 100b is shown. The number of glass substrates 1 can be an odd number or an even number.

[0069] In some embodiments, as Figure 1 As shown, for a core glass substrate 100a, that is, one of at least a pair of adjacent glass substrates 1 is a double conductive layer glass substrate 1a, and the other is a single conductive layer glass substrate 1b. In this case, as shown in FIG. Figure 3 As shown, the thickness of the double-conductive-layer glass substrate 1a is, for example, 50 μm to 2000 μm, for example, 500 μm. Two conductive circuit pattern layers 2 are provided in the double-conductive-layer glass substrate 1a, and the two conductive circuit pattern layers 2 are exposed on two opposing surfaces of the double-conductive-layer glass substrate 1a. At least one first conductive connecting portion 3 is provided in the double-conductive-layer glass substrate 1a, and the two ends of the first conductive connecting portion 3 are respectively interconnected with the two conductive circuit pattern layers 2 of the double-conductive-layer glass substrate 1a. Specifically, the double-conductive-layer glass substrate 1a is provided with a first through-hole 3a, and the two ends of the first through-hole 3a extend to the bottom surface of the groove 11 located on the two opposing surfaces of the glass substrate 1. The first through-hole 3a is filled with the first conductive connecting portion 3, and the two ends of the first conductive connecting portion 3 are respectively interconnected with the two conductive circuit pattern layers 2 located in the groove 11 located on the two opposing surfaces of the glass substrate 1. First through-hole 3a is a through-glass via (TGV) that penetrates glass substrate 1. The radial cross-section of first through-hole 3a is, for example, circular. By interconnecting the ends of first conductive connection portion 3 with two layers of conductive patterned layers 2 located in grooves 11 on two opposing surfaces of glass substrate 1, an electrical interconnection structure can be formed that penetrates glass substrate 1.

[0070] like Figure 4As shown, the thickness of the single conductive layer glass substrate 1b is, for example, 50 μm to 2000 μm, for example, 100 μm. A conductive circuit pattern layer 2 is provided in the single conductive layer glass substrate 1b. The conductive circuit pattern layer 2 is exposed on the surface of the single conductive layer glass substrate 1b away from the double conductive layer glass substrate 1a (i.e., Figure 4 The single conductive layer glass substrate 1b is shown with its surface facing upward. At least one second conductive connection portion 4 is provided in the single conductive layer glass substrate 1b. One end of the second conductive connection portion 4 is interconnected with the conductive circuit pattern layer 2 of the single conductive layer glass substrate 1b, and the other end is interconnected with the adjacent conductive circuit pattern layer 2 of the double conductive layer glass substrate 1a. Specifically, a second through hole 4a is provided in the single conductive layer glass substrate 1b. One end of the second through hole 4a extends to the bottom surface of the groove 12 of the single conductive layer glass substrate 1b, and the other end of the second through hole 4a extends to the surface of the single conductive layer glass substrate 1b on the side closest to the double conductive layer glass substrate 1a. The second through hole 4a is filled with the second conductive connection portion 4. One end of the second conductive connection portion 4 is interconnected with the conductive circuit pattern layer 2 located in the groove 12, and the other end is interconnected with the conductive circuit pattern layer 2 of the adjacent double conductive layer glass substrate 1a. In other words, the conductive circuit pattern layer 2 of the single conductive layer glass substrate 1b is interconnected with the conductive circuit pattern layer 2 of the adjacent double conductive layer glass substrate 1a via the second conductive connection portion 4.

[0071] The opposing surfaces of the double-conductive-layer glass substrate 1a and the single-conductive-layer glass substrate 1b include glass-to-glass bonding areas, bonding areas between the conductive circuit pattern layer 2 and the second conductive connection portion 4, and bonding areas between the glass and the conductive circuit pattern layer 2. Thus, the present application achieves direct bonding between the double-conductive-layer glass substrate 1a and the single-conductive-layer glass substrate 1b.

[0072] In some embodiments, as Figure 2 As shown, for a coreless glass substrate 100b, that is, at least one pair of adjacent glass substrates 1 are both single conductive layer glass substrates 1b. In this case, as Figure 4As shown, the opposing surfaces of each single-conductive-layer glass substrate 1b are a first surface 1b1 and a second surface 1b2, respectively. The first surface 1b1 of each single-conductive-layer glass substrate 1b is opposite the second surface 1b2 of an adjacent single-conductive-layer glass substrate 1b. Each single-conductive-layer glass substrate 1b is provided with a conductive circuit pattern layer 2, which is exposed on the first surface 1b1. Each single-conductive-layer glass substrate 1b is provided with at least one conductive connection portion (i.e., a second conductive connection portion 4). One end of the conductive connection portion (i.e., the second conductive connection portion 4) is interconnected with the conductive circuit pattern layer 2 of the corresponding single-conductive-layer glass substrate 1b, and the other end is interconnected with the conductive circuit pattern layer 2 of the adjacent single-conductive-layer glass substrate 1b. Since the specific structure of the single-conductive-layer glass substrate 1b has been described in detail above, it will not be repeated here.

[0073] The first surface 1b1 of each single-conductive-layer glass substrate 1b and the second surface 1b2 of the adjacent single-conductive-layer glass substrate 1b include glass-to-glass bonding areas, bonding areas between the conductive circuit pattern layer 2 and the conductive connection portion, and bonding areas between the glass and the conductive circuit pattern layer 2. Thus, the present application achieves direct bonding between adjacent single-conductive-layer glass substrates 1b.

[0074] In some embodiments, the exposed surface of the conductive circuit pattern layer 2 is recessed relative to the surface of the glass substrate 1 on the same side before the bonding process, and is flush with the surface of the glass substrate 1 on the same side after the bonding process. In other words, the conductive circuit pattern layer 2 needs to be made of a metal material with a greater thermal expansion coefficient than the surrounding glass. This allows the bonding of the conductive circuit pattern layer 2 to the other conductive circuit pattern layer 2 by utilizing the volume expansion of the conductive circuit pattern layer 2, allowing the exposed surface of the conductive circuit pattern layer 2 to be flush with the surface of the glass substrate 1 on the same side and in contact with the corresponding conductive circuit pattern layer 2. During this process, the metal atoms of the two conductive circuit pattern layers 2 diffuse into each other's crystal lattices, thereby achieving a secure bond between the two conductive circuit pattern layers 2.

[0075] As another technical solution, see Figure 5 , and combined with Figures 1 to 4 The present invention also provides a method for manufacturing a packaging substrate 100, including:

[0076] S1. Provide at least two glass substrates 1; each glass substrate 1 is provided with at least one conductive circuit pattern layer 2, and a portion of each conductive circuit pattern layer 2 is exposed on one of two opposing surfaces of the glass substrate 1;

[0077] S2, performing a bonding process on at least two of all the glass substrates 1 in sequence according to a preset order;

[0078] The bonding connection between glass and glass, the bonding connection between the conductive circuit pattern layer 2 and the conductive circuit pattern layer 2, and the bonding connection between glass and the conductive circuit pattern layer 2 are completed in one bonding process.

[0079] The embodiments of the present application utilize the aforementioned bonding method, eliminating the prior art issues of microcracks and delamination that can occur during the production and use of the package substrate 100 due to inconsistent thermal expansion coefficients between the glass and the insulating layer, thereby improving connection reliability. Furthermore, the aforementioned bonding method allows for the flexible and unrestricted combination of glass substrates 1 of different types and quantities.

[0080] In some embodiments, before the bonding process, the exposed surface of the conductive circuit pattern layer 2 is concave inwardly relative to the surface of the glass substrate 1 on the same side; during the bonding process, the conductive circuit pattern layer 2 expands due to heat, and after the bonding process, the exposed surface of the conductive circuit pattern layer 2 is flush with the surface of the glass substrate 1 on the same side, thereby achieving bonding connection between the conductive circuit pattern layer 2 and the corresponding conductive circuit pattern layer 2 or glass.

[0081] Furthermore, in some embodiments, the distance between the exposed surface of the conductive circuit pattern layer 2 and the surface of the glass substrate 1 on the same side before the bonding process can be greater than or equal to 1 nm and less than or equal to 3 μm, for example, 5 nm. By setting the distance within this numerical range, the exposed surface of the conductive circuit pattern layer 2 can be in contact with the corresponding conductive circuit pattern layer 2, thereby achieving a strong bond between the two conductive circuit pattern layers 2.

[0082] In some embodiments, as Figure 6 As shown, the above bonding process includes:

[0083] S21, processing the surface of the glass substrate 1 for stacking with other glass substrates 1 to improve the surface flatness;

[0084] S22, performing activation treatment on the surface of the glass substrate 1 for stacking with other glass substrates 1;

[0085] S23, performing initial bonding on at least two glass substrates 1 to be bonded at a first temperature;

[0086] S24 , bonding the at least two glass substrates 1 to be bonded at a second temperature; the second temperature is higher than the first temperature.

[0087] In the above-mentioned step S21, the surface treatment method includes, for example, mechanical polishing, chemical polishing, electrochemical polishing, chemical mechanical polishing (CMP), ultrasonic polishing, magnetic grinding polishing, fluid polishing, etc. Surface treatment is a key step in the direct bonding process, which is used to remove impurities on the surface of the glass substrate 1 for overlapping with other glass substrates 1 and reduce defects such as bubbles and microcracks. The impurities include, for example, oxides, organic matter or other impurities on the surface of the glass or metal. By removing these impurities, it is possible to avoid the presence of impurities that cause air gaps or weak bonding points to form at the bonding interface, thereby causing the problem of insufficient bonding strength. In addition, surface treatment can also improve the flatness of the surface of the glass substrate 1 for overlapping with other glass substrates 1. For example, chemical mechanical polishing (CMP) can ensure that the surface is smooth and flat. CMP can control the surface roughness to the nanometer level, ensuring close contact at the bonding interface. Thus, through surface treatment, the overall quality and reliability of the glass substrate 1 can be improved.

[0088] In step S22, the activation treatment can be used to increase the chemical activity of the surface and promote metal bonding. Specifically, the activation treatment can generate reactive groups on the glass surface, such as hydroxyl (-OH) and carboxyl (-COOH). These groups can enhance the chemical activity of the surface and promote the formation of intermolecular forces (such as van der Waals forces). Moreover, the activation treatment significantly increases the surface energy, making it easier for the surface to form bonds with other surfaces.

[0089] In the above-mentioned step S23, initial bonding is used to make the surfaces of at least two glass substrates 1 to be bonded in close contact by intermolecular forces (such as van der Waals forces), reduce the gap of the bonding interface, thereby realizing that the surfaces of at least two glass substrates 1 to be bonded are preliminarily connected together at room temperature, which helps to reduce the thermal stress generated during the heating process and improve the reliability of the bonding. Although these forces are relatively weak, they can be further enhanced during the subsequent step S24. Initial bonding ensures that the surfaces of at least two glass substrates 1 to be bonded can be in close contact after alignment, providing a basis for subsequent bonding steps. In addition, initial bonding helps to further improve the flatness of the surface, ensures the alignment, uniformity and consistency of the bonding interface. In addition, initial bonding can be regarded as a pre-bonding step, which provides a stable initial state for subsequent bonding steps, and helps to form a stronger covalent bond under high temperature conditions.

[0090] In some embodiments, in the above step S23 , the first temperature is, for example, room temperature (eg, 20° C.-25° C.).

[0091] In the above step S24, under high temperature conditions (i.e., the second temperature), the thermal motion of the atoms or ions in the glass is intensified, so that the atoms or ions on the surface between the glass and the glass can be rearranged and combined, thereby forming a stronger covalent bond, further enhancing the bonding strength; between metal and metal, because the thermal expansion coefficient of the metal is greater than that of the glass around it, the volume of the metal will expand, causing the metal to contact each other. Under high temperature conditions, the metal atoms diffuse between the glass and the glass and enter the crystal lattice of each other, thereby achieving a strong bond between copper and copper. The bond between glass and metal (dielectric bonding, hybrid bonding) is a chemical reaction or physical change under high temperature conditions to form a stronger bond.

[0092] In step S24 , to achieve the above-mentioned effect, in some embodiments, the second temperature is greater than or equal to 200° C. and less than or equal to 800° C., for example, 200° C., 300° C., 400° C., 500° C., 600° C., 700° C., 800° C., etc. A preferred range is greater than or equal to 400° C. and less than or equal to 600° C.

[0093] In some embodiments, for a core glass substrate 100a, that is, all glass substrates 1 include a double conductive layer glass substrate 1a and at least two single conductive layer glass substrates 1b; the above step S2 specifically includes:

[0094] performing at least one bonding process;

[0095] In some examples, during each bonding process, two single conductive layer glass substrates 1b are simultaneously bonded to the double conductive layer glass substrate 1a or the single conductive layer glass substrate 1b on opposite sides of the double conductive layer glass substrate 1a. In other examples, during each bonding process, one single conductive layer glass substrate 1b is bonded to the double conductive layer glass substrate 1a or the single conductive layer glass substrate 1b on one of the opposite sides of the double conductive layer glass substrate 1a.

[0096] In a specific embodiment, the method for manufacturing the double-conductive-layer glass substrate 1a specifically includes:

[0097] S101、 Figure 7a As shown, a first through hole 3a is formed in the glass substrate 1, and both ends of the first through hole 3a extend to two opposite surfaces of the glass substrate 1;

[0098] In step S101, the first through hole 3a can be formed by laser induction and chemical etching (for example, chemical etching using hydrofluoric acid liquid). The aperture of the first through hole 3a is, for example, 100 μm.

[0099] S102, such as Figure 7bAs shown, a groove 11 is formed on two opposite surfaces of the glass substrate 1; both ends of the first through hole 3a are respectively located at the bottom surface of the groove 11 provided on the two opposite surfaces of the glass substrate 1;

[0100] In step S102, laser induction and chemical etching (for example, chemical etching using hydrofluoric acid liquid) can be used to form the groove 11. The depth of the groove 11 is, for example, 15 μm.

[0101] S103, a metal seed layer (e.g., a Ti / Cu layer) is formed in the groove 11 and the first through hole 3a by sputtering or deposition process to improve the adhesion of subsequent electroplating. The thickness of the metal seed layer is, for example, 0.2 μm. Then, a metal material (e.g., Cu) is filled in the first through hole 3a and the groove 11 by electroplating to form a first conductive connection portion 3 in the first through hole 3a and a conductive circuit pattern layer 2 in the groove 11. The first conductive connection portion 3 is interconnected with the two layers of the conductive circuit pattern layer 2 respectively. The structure of the double-conductive layer glass substrate 1a after completing step S103 is as follows: Figure 3 The thickness of the metal seed layer is, for example, 0.2 μm.

[0102] In a specific embodiment, the method for manufacturing the single conductive layer glass substrate 1b specifically includes:

[0103] S201, forming a second through hole 4a in the glass substrate 1, wherein both ends of the second through hole 4a extend to two opposite surfaces of the glass substrate 1;

[0104] In step S201, the second through hole 4a can be formed by laser induction and chemical etching (for example, chemical etching using hydrofluoric acid liquid). The aperture of the second through hole 4a is, for example, 60 μm.

[0105] S202, forming a groove 11 on one of the two opposite surfaces of the glass substrate 1; one end of the second through hole 4a is located at the bottom surface of the groove 11;

[0106] In step S202, laser induction and chemical etching (for example, chemical etching using hydrofluoric acid liquid) may be used to form the groove 11. The depth of the groove 11 is, for example, 15 μm.

[0107] S203, a metal seed layer (e.g., a Ti / Cu layer) is formed in the groove 11 and the second through hole 4a by sputtering or deposition process to improve the adhesion of subsequent electroplating. The thickness of the metal seed layer is, for example, 0.2 μm. Then, a metal material (e.g., Cu) is filled in the second through hole 4a and the groove 11 by electroplating to form a second conductive connection portion 4 in the second through hole 4a, and a conductive circuit pattern layer 2 is formed in the groove 11. The second conductive connection portion 4 is interconnected with the conductive circuit pattern layer 2. The structure of the single conductive layer glass substrate 1b after step S203 is as follows: Figure 4 shown. Figure 7c The two single conductive layer glass substrates 1b shown can both be obtained by using the above-mentioned manufacturing method.

[0108] On this basis, Figure 1 The bonding process of the cored glass substrate 100a shown may include two bonding processes:

[0109] In the first bonding process, the two opposite sides of the double conductive layer glass substrate 1a are bonded simultaneously or successively. Figure 7c The two single conductive layer glass substrates 1b are respectively Figure 7b The double conductive glass substrate 1a is bonded to form Figure 7d The structure shown.

[0110] In the second bonding process, the two opposite sides of the double conductive layer glass substrate 1a are bonded simultaneously or successively. Figure 7c Two identical or similar single conductive layer glass substrates 1b are respectively Figure 7d The two single conductive layer glass substrates 1b are bonded to form Figure 1 The structure shown.

[0111] In some embodiments, for a coreless glass substrate 100 b , that is, all glass substrates 1 are single conductive layer glass substrates 1 b ;

[0112] In some examples, the above step S2 specifically includes:

[0113] performing at least one bonding process;

[0114] In each bonding process, the (i+1)th single conductive layer glass substrate 1b is bonded to the (i)th single conductive layer glass substrate 1b on one side of the (i)th single conductive layer glass substrate 1b, where i=1, 2, ..., N, where N is the total number of single conductive layer glass substrates 1b, and the remaining single conductive layer glass substrates 1b except the first single conductive layer glass substrate 1b are all located on the same side of the first single conductive layer glass substrate 1b.

[0115] In a specific embodiment, Figure 8 As shown, Figure 2 The bonding process of the coreless glass substrate 100b shown may include three bonding processes:

[0116] In the first bonding process, on one side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 ), bonding the second single conductive layer glass substrate 1b12 to the first single conductive layer glass substrate 1b11, and the bonded glass substrate structure is 1b10;

[0117] In the second bonding process, on one side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 ), bonding the third single conductive layer glass substrate 1b13 to the second single conductive layer glass substrate 1b12, and the bonded glass substrate structure is 1b20;

[0118] In the third bonding process, on one side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 ), the fourth single conductive layer glass substrate 1b14 is bonded to the third single conductive layer glass substrate 1b13, and the glass substrate structure after bonding is 1b30.

[0119] The second single conductive layer glass substrate 1b11, the third single conductive layer glass substrate 1b13 and the fourth single conductive layer glass substrate 1b14 are all located on the same side of the first single conductive layer glass substrate 1b (ie Figure 8 on the upper side of the ).

[0120] In some other examples, the above step S2 specifically includes:

[0121] performing the bonding process at least twice;

[0122] In the jth bonding process, one of the single conductive layer glass substrates 1b is bonded to a corresponding single conductive layer glass substrate 1b at one of the first and second sides of the first single conductive layer glass substrate 1b, which are opposite to each other.

[0123] In the kth bonding process, one of the single conductive layer glass substrates 1b is bonded to a corresponding single conductive layer glass substrate 1b on the other of the first and second sides of the first single conductive layer glass substrate 1b;

[0124] Wherein, j is an odd number in the 1st to Mth bonding processes, k is an even number in the 1st to Mth bonding processes, M is the total number of bonding processes, and M=N-1, N is the total number of single conductive layer glass substrates 1b.

[0125] In a specific embodiment, Figure 9As shown, another bonding process of the coreless glass substrate 100b may include three bonding processes:

[0126] In the first bonding process, on one side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 ), bonding the second single conductive layer glass substrate 1b12 to the first single conductive layer glass substrate 1b11, and the bonded glass substrate structure is 1b10;

[0127] In the second bonding process, on the other side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 ), bonding the third single conductive layer glass substrate 1b13 to the first single conductive layer glass substrate 1b11, and the bonded glass substrate structure is 1b20;

[0128] In the third bonding process, on one side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 ), the fourth single conductive layer glass substrate 1b14 is bonded to the second single conductive layer glass substrate 1b12, and the glass substrate structure after bonding is 1b30.

[0129] In the odd-numbered bonding process, on one side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 and in the even-numbered bonding process, on the other side of the first single conductive layer glass substrate 1b11 (i.e. Figure 8 In this case, the second single conductive layer glass substrate 1b11 and the fourth single conductive layer glass substrate 1b14 are both located on one side of the first single conductive layer glass substrate 1b (i.e. Figure 8 The third single conductive layer glass substrate 1b13 is located on the other side of the first single conductive layer glass substrate 1b11 (ie Figure 8 on the lower side of the ).

[0130] As can be seen from the above, the present application can freely and flexibly combine glass substrates of different types and quantities by adopting the above bonding method.

[0131] In some embodiments, the method for manufacturing the package substrate 100 further includes:

[0132] A chemical etching method is used to perform a cutting process on all the glass substrates 1 after the bonding process is completed.

[0133] The above steps are used to cut all the bonded glass substrates (large-size substrates) into multiple small-size substrates.

[0134] Conventional mechanical cutting or laser cutting may introduce microcracks or chipping on the surface of the glass substrate 1. However, the chemical etching method used in this application removes material through chemical reaction rather than physical force, thereby avoiding the generation of mechanical stress and reducing the risk of microcracks and chipping. Furthermore, reducing microcracks and chipping helps maintain the integrity and mechanical strength of the glass substrate 1.

[0135] In some embodiments, after all glass substrates are connected through a bonding process, the method for manufacturing the package substrate 100 further includes:

[0136] The solder resist coating step is to cover the surface of the substrate with a layer of solder resist ink to prevent welding or bridging, insulation, and protect the substrate.

[0137] The connection pad surface treatment step (such as ENEPIG process) is used to treat the connection pad surface to form a uniform metal layer with good conductivity and oxidation resistance to ensure the reliability and stability of subsequent electrical connections.

[0138] In the cutting step, a chemical etching method is used to cut all the glass substrates 1 after the bonding process is completed.

[0139] The cutting step is used to divide the entire large-sized substrate into multiple small-sized substrates to facilitate subsequent processing and handling. For example, a quartering method is used to divide the entire large-sized substrate into four small-sized substrates. The size of the small-sized substrate is one-fourth the size of the large-sized substrate. The specific process of the chemical etching method is: first, a laser is used to induce a cutting path on the large-sized substrate, and then a solution such as hydrofluoric acid (HF) is used to chemically etch the large-sized substrate to remove the glass material on the cutting path. This method can avoid or reduce defects such as microcracks and fragmentation of the glass caused by mechanical cutting.

[0140] The SOP (Solder On Pad) step is used to interconnect the substrate and chip bumps during packaging.

[0141] The single block segmentation step is used to further segment the small-sized substrate to obtain the final product unit.

[0142] Testing steps, test product units to ensure that their quality and performance meet the requirements.

[0143] The inspection steps include, for example, appearance inspection, dimension inspection, electrical performance inspection, reliability inspection, and the like.

[0144] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present application, and such modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. A packaging substrate, characterized in that: The invention comprises at least two glass substrates stacked in sequence, each of the glass substrates being provided with at least one conductive circuit pattern layer, and a portion of each conductive circuit pattern layer being exposed on one of two opposite surfaces of the glass substrates; The surfaces facing each other of at least one pair of adjacent glass substrates include glass-to-glass bonding areas, bonding areas between the conductive circuit pattern layers and bonding areas between the conductive circuit pattern layers, and bonding areas between the glass and the conductive circuit pattern layers.

2. The packaging substrate according to claim 1, wherein: At least one of the two opposite surfaces of the glass substrate is formed with a groove, and the conductive circuit pattern layer is arranged in the groove.

3. The packaging substrate according to claim 1 or 2, wherein: One of at least one pair of adjacent glass substrates is a double-conductive-layer glass substrate, and the other is a single-conductive-layer glass substrate; The double-conductive-layer glass substrate is provided with two layers of the conductive circuit pattern layers, and the two layers of the conductive circuit pattern layers are respectively exposed on two opposite surfaces of the double-conductive-layer glass substrate; the double-conductive-layer glass substrate is provided with at least one first conductive connecting portion, and the two ends of the first conductive connecting portion are respectively interconnected with the two layers of the conductive circuit pattern layers of the double-conductive-layer glass substrate; The single conductive layer glass substrate is provided with a conductive circuit pattern layer, the conductive circuit pattern layer being exposed on a surface of the single conductive layer glass substrate away from the double conductive layer glass substrate; the single conductive layer glass substrate is provided with at least one second conductive connection portion, one end of the second conductive connection portion being interconnected with the conductive circuit pattern layer of the single conductive layer glass substrate, and the other end being interconnected with the adjacent conductive circuit pattern layer of the double conductive layer glass substrate; The surfaces of the double-conductive-layer glass substrate and the single-conductive-layer glass substrate facing each other include the bonding connection area between glass and glass, the bonding connection area between the conductive circuit pattern layer and the second conductive connection part, and the bonding connection area between glass and the conductive circuit pattern layer.

4. The packaging substrate according to claim 1 or 2, wherein: At least one pair of adjacent glass substrates are both single conductive layer glass substrates; The surfaces of each single conductive layer glass substrate facing away from each other are respectively a first surface and a second surface, and the first surface of each single conductive layer glass substrate is opposite to the second surface of the adjacent single conductive layer glass substrate; Each of the single-conductive-layer glass substrates is provided with a conductive circuit pattern layer, and the conductive circuit pattern layer is exposed on the first surface; each of the single-conductive-layer glass substrates is provided with at least one conductive connecting portion, one end of the conductive connecting portion is interconnected with the conductive circuit pattern layer of the single-conductive-layer glass substrate, and the other end is interconnected with the conductive circuit pattern layer of the adjacent single-conductive-layer glass substrate; The first surface of each single conductive layer glass substrate and the second surface of the adjacent single conductive layer glass substrate include a glass-to-glass bonding connection area, a bonding connection area between the conductive circuit pattern layer and the conductive connection part, and a bonding connection area between glass and the conductive circuit pattern layer.

5. The packaging substrate according to claim 1 or 2, wherein: The exposed surface of the conductive circuit pattern layer is concave inwardly of the surface of the glass substrate on the same side before the bonding process, and is flush with the surface of the glass substrate on the same side after the bonding process.

6. A method for manufacturing a packaging substrate, characterized in that: include: providing at least two glass substrates; At least one conductive circuit pattern layer is provided on each of the glass substrates, and a portion of each conductive circuit pattern layer is exposed on one of two opposite surfaces of the glass substrate; performing a bonding process on at least two of all the glass substrates in sequence according to a preset order; Wherein, the bonding connection between glass and glass, the bonding connection between the conductive circuit pattern layers and the bonding connection between glass and the conductive circuit pattern layer are completed in one bonding process.

7. The method for manufacturing a package substrate according to claim 6, wherein: Before the bonding process is performed, the exposed surface of the conductive circuit pattern layer is recessed into the surface of the glass substrate on the same side; During the bonding process, the conductive circuit pattern layer expands due to heat, and after the bonding process, the exposed surface of the conductive circuit pattern layer is flush with the surface of the glass substrate on the same side, so as to achieve bonding connection between the conductive circuit pattern layer and the corresponding conductive circuit pattern layer or glass.

8. The method for manufacturing a packaging substrate according to claim 7, wherein: Before the bonding process, the distance between the exposed surface of the conductive circuit pattern layer and the surface of the glass substrate on the same side is greater than or equal to 1 nm and less than or equal to 3 μm.

9. The method for manufacturing a package substrate according to claim 6, wherein: The bonding process includes: Processing a surface of the glass substrate for stacking with other glass substrates to improve surface flatness; performing an activation treatment on a surface of the glass substrate for stacking with other glass substrates; Performing initial bonding on at least two glass substrates to be bonded at a first temperature; The at least two glass substrates to be bonded are bonded at a second temperature; the second temperature is higher than the first temperature.

10. The method for manufacturing a package substrate according to claim 9, wherein: The second temperature is greater than or equal to 200° C. and less than or equal to 800° C.

11. The method for manufacturing a packaging substrate according to any one of claims 6 to 10, wherein: All of the glass substrates include a double conductive layer glass substrate and at least two single conductive layer glass substrates; The step of performing a bonding process on at least two of all the glass substrates in a preset order includes: performing at least one bonding process; In each bonding process, two of the single conductive layer glass substrates are bonded to the double conductive layer glass substrate or the single conductive layer glass substrate on opposite sides of the double conductive layer glass substrate; or, one of the single conductive layer glass substrates is bonded to the double conductive layer glass substrate or the single conductive layer glass substrate on one of the opposite sides of the double conductive layer glass substrate.

12. The method for manufacturing a packaging substrate according to any one of claims 6 to 10, wherein: All of the glass substrates are single conductive layer glass substrates; The step of performing a bonding process on at least two of all the glass substrates in a preset order includes: performing at least one bonding process; In each bonding process, the (i+1)th single conductive layer glass substrate is bonded to the (i)th single conductive layer glass substrate on one side of the (i)th single conductive layer glass substrate, where i=1, 2, ..., N, where N is the total number of the single conductive layer glass substrates, and the remaining single conductive layer glass substrates except the first single conductive layer glass substrate are all located on the same side of the first single conductive layer glass substrate.

13. The method for manufacturing a packaging substrate according to any one of claims 6 to 10, characterized in that: All of the glass substrates are single conductive layer glass substrates; The step of performing a bonding process on at least two of all the glass substrates in a preset order includes: performing the bonding process at least twice; wherein, in the jth bonding process, one of the single conductive layer glass substrates is bonded to the corresponding single conductive layer glass substrate at one of the first and second sides of the first single conductive layer glass substrate, which are opposite to each other; In the kth bonding process, one of the single conductive layer glass substrates is bonded to the corresponding single conductive layer glass substrate on the other of the first and second sides of the first single conductive layer glass substrate, which are opposite to each other; Wherein, j is an odd number in the 1st to Mth bonding processes, k is an even number in the 1st to Mth bonding processes, M is the total number of bonding processes, and M=N-1, where N is the total number of the single conductive layer glass substrates.

14. The method for manufacturing a package substrate according to claim 6, wherein: Also includes: A chemical etching method is used to perform a cutting process on all the glass substrates after the bonding process is completed.

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