Manufacturing method of glass substrate with locally thickened copper layer and glass substrate

Abstract

The invention discloses a manufacturing method of a glass substrate with a locally thickened copper layer and the glass substrate, and relates to the field of glass substrate manufacturing. The method comprises the following steps: providing a glass substrate main body; a conductive adhesive layer and a copper foil layer are sequentially laminated on at least one surface of the glass substrate main body; bonding the glass substrate main body, the conductive adhesive layer and the copper foil layer into a whole through a hot pressing process to obtain a composite structure; performing depth-controlled milling treatment on a specified position of the composite structure so as to expose a target copper layer in an area on the glass substrate main body, wherein the area is about to form a locally thickened copper layer; carrying out electroplating deposition on the surface of the target copper layer to form a locally thickened copper layer; and removing the residual copper foil layer and conductive adhesive layer on the surface of the composite structure to obtain the glass substrate with the locally thickened copper layer. The technical problem that when the current-carrying heat dissipation capacity of an existing glass substrate is improved, the design requirements for high-density wiring and hole arrangement are difficult to meet at the same time is solved.

Description

Technical Field

[0001] The present invention relates to the field of glass substrate manufacturing, and in particular to a method for manufacturing a glass substrate with a locally thickened copper layer and the glass substrate. Background Art

[0002] Glass substrates, due to their excellent mechanical strength, low thermal expansion coefficient, and high dimensional stability, have become an increasingly important substrate for integrated circuits and packaging, particularly in achieving high-density via and wiring patterns. However, existing processes hinder the effective conduction of heat generated by chips and components through the copper layer of glass substrates, impacting the long-term reliability of electronic systems.

[0003] To address the heat dissipation issue, current technologies mainly optimize through three approaches: the first is to widen the conductor lines to reduce the resistive thermal effect while ensuring electrical functionality. However, due to the requirements of line spacing and signal integrity, the line width adjustment space is extremely limited, which is particularly prone to impedance mismatch in ultra-thin multi-layer designs. The second is to apply thermal adhesive to the entire surface after the components are mounted to enhance heat dissipation. However, this process has problems such as difficulty in controlling coating uniformity, increased assembly complexity, and interface thermal resistance. After the thermal adhesive is cured, it may interfere with subsequent repair or inspection processes. The third is to add non-functional metallized heat dissipation holes to improve the heat conduction path. However, in high-density wiring areas, the additional holes will occupy the original wiring space, exacerbate design conflicts, and even reduce the mechanical strength of the glass substrate. In other words, none of the above solutions have been able to fundamentally break the contradiction between the heat dissipation capacity of the thin copper layer and the demand for high-density wiring, resulting in the application of glass substrates in high-end electronic devices being restricted.

[0004] Therefore, how to improve the current-carrying and heat-dissipating capacity while taking into account the high-density wiring and hole layout design requirements of the glass substrate is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The present invention provides a method for manufacturing a glass substrate with a locally thickened copper layer and a glass substrate, so as to solve the technical problem that existing glass substrates are difficult to simultaneously meet the requirements of high-density wiring and hole layout design when improving the current carrying and heat dissipation capabilities.

[0006] In a first aspect, a method for manufacturing a glass substrate having a locally thickened copper layer is provided, comprising: providing a glass substrate body; A conductive adhesive layer and a copper foil layer are sequentially stacked on at least one surface of the glass substrate body; Bonding the glass substrate body, the conductive adhesive layer, and the copper foil layer into one body through a hot pressing process to obtain a composite structure; Performing a controlled-depth milling process on a designated position of the composite structure to expose a target copper layer on the glass substrate body where a local thickened copper layer is to be formed; Performing electroplating deposition on the surface of the target copper layer to form a locally thickened copper layer; The residual copper foil layer and the conductive adhesive layer on the surface of the composite structure are removed to obtain a glass substrate with a locally thickened copper layer.

[0007] In one embodiment, the glass substrate body is manufactured by the following method: Providing raw glass substrates; Performing hole metallization processing on the original glass substrate to form a metallized through-hole structure; Conductor circuit patterning is performed on the surface of the original glass substrate after the hole metallization process is completed to obtain a prepared glass substrate body.

[0008] In one embodiment, the conductive adhesive layer includes a first conductive adhesive layer and a second conductive adhesive layer, and the copper foil layer includes a first copper foil layer and a second copper foil layer; The method of sequentially stacking a conductive adhesive layer and a copper foil layer on at least one surface of the glass substrate body comprises: Disposing the first conductive adhesive layer on the first surface of the glass substrate body, and disposing the first copper foil layer on the first conductive adhesive layer; and / or, The second conductive adhesive layer is disposed on the second surface of the glass substrate body, and the second copper foil layer is disposed on the second conductive adhesive layer.

[0009] In one embodiment, the thickness of the copper foil layer is 5 μm-50 μm, and / or the thickness of the conductive adhesive layer is 15 μm-100 μm.

[0010] In one embodiment, the hot pressing process has a temperature of 75° C.-125° C., a pressure of 1.0 kgf / cm²-5.0 kgf / cm², and a duration of 15 seconds-60 seconds.

[0011] In one embodiment, the controlling the depth of the milling process on the designated position of the composite structure to expose the target copper layer on the glass substrate body where the local thickened copper layer is to be formed includes: According to a preset milling trajectory and preset depth parameters, one or more controlled-depth milling processes are performed on a designated position of the composite structure to expose a target copper layer in an area on the glass substrate body where a local thickened copper layer is to be formed; The preset milling trajectory is a path predetermined according to the shape and size of the designated position, and the preset depth parameter is a parameter predetermined according to the thickness of the conductive adhesive layer and the copper foil layer.

[0012] In one embodiment, removing the residual copper foil layer and the conductive adhesive layer on the surface of the composite structure to obtain a glass substrate with a locally thickened copper layer includes: removing the residual copper foil layer on the surface of the composite structure by chemical treatment or mechanical treatment to obtain a first-treated composite structure; A potassium permanganate solution or a sodium hydroxide solution of a preset concentration is used to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time, so as to obtain a glass substrate with a locally thickened copper layer.

[0013] In one embodiment, the step of dissolving the conductive adhesive layer on the surface of the composite structure treated for the first time using a potassium permanganate solution or a sodium hydroxide solution with a preset concentration to obtain a glass substrate having a locally thickened copper layer comprises: dissolving the conductive adhesive layer on the surface of the composite structure treated for the first time using a potassium permanganate solution or a sodium hydroxide solution with a preset concentration to obtain a composite structure treated for the second time; The composite structure subjected to the second treatment is subjected to plasma desmear treatment to obtain a glass substrate having a locally thickened copper layer.

[0014] In one embodiment, the thickness of the locally thickened copper layer is determined by: Obtaining an electrical characteristic parameter group for the specified position, the electrical characteristic parameter group including a target resistance value, a wiring length, a designed line width value, and a copper layer resistivity, wherein the target resistance value is a maximum resistance value of an external interconnection device at the specified position, the wiring length is an actual path length of a line corresponding to the specified position in the glass substrate body, and the designed line width value is a preset line width at the specified position in the glass substrate body; Performing process correction on the designed line width according to the etching compensation factor to obtain an actual line width value; The thickness of the locally thickened copper layer is obtained according to the target resistance value, the wiring length, the designed line width value, and the resistivity of the copper layer.

[0015] In a second aspect, a glass substrate with a locally thickened copper layer is provided, wherein the glass substrate is manufactured using the method for manufacturing a glass substrate with a locally thickened copper layer according to the first aspect.

[0016] The beneficial effect of a technical solution provided by the present invention is as follows: a composite structure is constructed by sequentially stacking a conductive adhesive layer and a copper foil layer on the surface of a glass substrate body and hot pressing and bonding them. Then, a controlled depth milling process is used to precisely act on the designated position, removing only the copper foil layer and the conductive adhesive layer at the designated position, exposing the area to be thickened while effectively avoiding damage to the glass substrate body, ensuring that the circuit layout in the area not to be thickened is not disturbed, and meeting the stringent requirements of high-density wiring for space utilization. Furthermore, electroplating deposition is performed on the surface of the target copper layer in the area to be thickened to form a locally thickened copper layer, thereby achieving improved current carrying capacity and heat conduction efficiency while retaining the thin copper layer design in the non-thickened area, and taking into account the signal integrity requirements of fine circuits. There is no need to thicken the copper layer as a whole or to add an additional heat dissipation structure, which solves the technical problem that the existing glass substrate is difficult to meet the requirements of high-density wiring and hole layout design while improving the current carrying and heat dissipation capacity, thereby enhancing the reliability and applicability of the glass substrate in high-power electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 is a flow chart of a method for manufacturing a glass substrate having a locally thickened copper layer according to an embodiment of the present invention; Figure 2 is a schematic diagram of a glass substrate body according to an embodiment of the present invention; Figure 3 This is an intermediate processing diagram of a glass substrate body according to one embodiment of the present invention; Figure 4 is another intermediate processing diagram of the glass substrate body in one embodiment of the present invention; Figure 5 is another intermediate processing diagram of the glass substrate body in one embodiment of the present invention; Figure 6 is another intermediate processing diagram of the glass substrate body in one embodiment of the present invention; Figure 7 is a schematic diagram of a composite structure processed for the first time in one embodiment of the present invention; Figure 8 FIG. 1 is a schematic diagram of a glass substrate having a locally thickened copper layer according to an embodiment of the present invention.

[0019] The reference numerals are as follows: 1- glass substrate body; 2A- first copper foil layer; 2B- second copper foil layer; 3A- first conductive adhesive layer; 3B- second conductive adhesive layer; X- designated position; Y- local thickened copper layer. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0023] In order to fully understand the present invention, please refer to Figures 1 to 8 The following description provides detailed structures and steps to illustrate the technical solutions proposed by the present invention. Preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other implementations.

[0024] First, as Figure 1 As shown, a method for manufacturing a glass substrate having a locally thickened copper layer Y is provided, comprising: S10, providing a glass substrate main body 1; S20 , sequentially stacking a conductive adhesive layer and a copper foil layer on at least one surface of the glass substrate body 1 .

[0025] In this embodiment, Figure 2 As shown, the glass substrate body 1 is a glass substrate body 1 after hole metallization and conductor circuit fabrication. The conductive adhesive can be an epoxy resin or polyimide conductive adhesive containing metal particles, and the conductive adhesive contains a conductive filler (one or more of copper powder, silver powder, or nickel powder) accounting for 10%-60% by weight. The copper foil layer can be electrolytic copper foil or rolled copper foil, which is used here as an example only.

[0026] The conductive adhesive layer includes a first conductive adhesive layer 3A and a second conductive adhesive layer 3B, and the copper foil layer includes a first copper foil layer 2A and a second copper foil layer 2B.

[0027] As an example, Figure 3 and Figure 4 As shown, a conductive adhesive layer and a copper foil layer are sequentially stacked on at least one surface of the glass substrate body 1, that is, a conductive adhesive layer and a copper foil layer are sequentially stacked on the first surface and / or the second surface of the glass substrate body 1, including: a first conductive adhesive layer 3A is disposed on the first surface of the glass substrate body, and a first copper foil layer 2A is disposed on the first conductive adhesive layer 3A; and / or a second conductive adhesive layer 3B is disposed on the second surface of the glass substrate body, and a second copper foil layer 2B is disposed on the second conductive adhesive layer 3B.

[0028] The first conductive adhesive layer 3A can be applied to the first surface of the glass substrate body 1 by a coating process (including but not limited to blade coating, roller coating, inkjet printing, or slit coating), and the second conductive adhesive layer 3B can be applied to the second surface of the glass substrate body 1 by a coating process. Subsequently, the surface of the copper foil layer in contact with the conductive adhesive layer is roughened (with a roughness Rz of 2μm-8μm, preferably 3μm or 6μm) and then laminated onto the surface of the conductive adhesive layer. Specifically, the first copper foil layer 2A can be disposed on the first conductive adhesive layer 3A, and the second copper foil layer 2B can be disposed on the second conductive adhesive layer 3B. In this embodiment, since the conductive adhesive layer is adhesive, by first applying the conductive adhesive layer and then the copper foil layer on the conductive adhesive layer, dust contamination during the manufacturing process can be effectively prevented, significantly improving the yield rate of subsequent processes.

[0029] S30 , bonding the glass substrate main body 1 , the conductive adhesive layer, and the copper foil layer into one body through a hot pressing process to obtain a composite structure.

[0030] In this embodiment, the temperature range of the hot pressing process can be 75°C-125°C. Within this temperature range, the conductive adhesive layer can be fully softened and exert its bonding properties without causing thermal damage to the glass substrate or the copper foil layer. The pressure range can be 1.0kgf / cm²-5.0kgf / cm². Within this pressure range, it can ensure that the layers of the composite structure are in full contact and exclude trapped bubbles, thereby improving the overall structural strength and electrical continuity. The duration range can be 15 seconds-60 seconds. Within this pressure range, the conductive adhesive layer can be cured and stress released, avoiding problems such as weak bonding, delamination or warping due to uneven pressing or insufficient time.

[0031] Preferably, the temperature of the hot pressing process can be 90°C, 100°C, 110°C or 120°C, the pressure of the hot pressing process can be 2.0kgf / cm², 3.0kgf / cm² or 4.0kgf / cm², and the duration of the hot pressing process can be 25 seconds, 35 seconds or 45 seconds.

[0032] As an example, taking a single-sided lamination of a 100μm thick glass substrate as an example, a hot pressing process at a temperature of 100°C, a pressure of 3.0kgf / cm², and a duration of 35 seconds can be used to bond the glass substrate, the conductive adhesive layer, and the copper foil layer together to form a composite structure. The process results: The conductive adhesive layer completely impregnates the roughened surface of the copper foil, and the interlayer peel strength reaches 1.2N / mm, a 40% improvement compared to room temperature lamination. The bubble residual rate is less than 0.5%, and the composite structure's surface flatness is ≤5μm. Experiments have demonstrated that the hot pressing process can achieve high-strength bonding (peel strength increased by 30%-50%), low defect rate (bubble rate less than 1%), and excellent electrical performance in composite structures under different scenarios, thereby improving interlayer bonding strength.

[0033] S40 , performing a controlled-depth milling process on a designated position X of the composite structure to expose a target copper layer in an area where a local thickened copper layer Y is to be formed on the glass substrate body 1 .

[0034] In this embodiment, the designated position X is an electrical connection position or electrical connection area on the glass substrate body 1 with external interconnected devices (including but not limited to chips and connectors), for example, a pad area for flip-chip bonding, a bonding point area for wire bonding, a pin contact area for plugging into an external connector, or a solder joint area for surface mount technology (SMT).

[0035] The target copper layer is an area corresponding to the designated position X on the glass substrate body 1 .

[0036] The shape of the designated position X and the target copper layer matches the contact interface of the external interconnection device, including but not limited to a circle, a rectangle or other shapes.

[0037] As an example, Figure 5 As shown, laser processing, CNC processing, or other processing methods can be used to perform controlled-depth milling at the designated location X of the composite structure. Laser processing includes, but is not limited to, UV laser processing and CO2 laser processing, and CNC processing includes, but is not limited to, water jet processing. Specifically, UV laser processing, CO2 laser processing, or water jet processing can be used to perform controlled-depth milling at the designated location X of the composite structure to expose the target copper layer on the glass substrate body 1 where the locally thickened copper layer Y is to be formed. Through UV laser processing, CO2 laser processing, and water jet processing, full coverage is achieved, from micron-level chip pads to millimeter-level connector areas. This creates technical advantages in precision, efficiency, and material compatibility, providing a clean, flat, and well-conductive target area for subsequent electroplating deposition, thereby improving the electrical connection reliability and manufacturing yield of the glass substrate.

[0038] Specifically, the UV laser processing parameters may range from a wavelength of 200 nm to 400 nm, a pulse frequency of 10 kHz to 100 kHz, and a power of 5 W to 50 W. Preferably, the wavelength may be 300 nm or 350 nm, the pulse frequency may be 50 kHz or 70 kHz, and the power may be 20 W or 35 W. The CO2 laser processing parameters may range from a wavelength of 9 μm to 11 μm, a continuous wave mode, and a power of 20 W to 200 W. Preferably, the wavelength may be 10 μm or 10.5 μm, and the power may be 100 W or 150 W. The water jet processing parameters may range from a water pressure of 300 MPa to 600 MPa, and an abrasive particle size of 200 mesh to 800 mesh. Preferably, the water pressure may be 400 MPa or 500 MPa, and the abrasive particle size may be 300 mesh or 600 mesh. It should be understood that the above is merely an example and does not constitute a limitation of the present invention.

[0039] S50 , performing electroplating deposition on the surface of the target copper layer to form a locally thickened copper layer Y.

[0040] As an example, Figure 6As shown, for surfaces where the target copper layer has been exposed, electroplating can be used to locally thicken the copper layer Y. Specifically, the composite structure, which has undergone controlled-depth milling, can be placed in an electroplating tank. The electrolyte can be an acidic copper electroplating solution containing copper sulfate, sulfuric acid, and appropriate additives (such as brighteners and levelers) to ensure good adhesion and uniformity of the plated layer. After connecting to a DC power supply, the target copper layer serves as the cathode, and a high-purity copper plate is used as the anode. The current is used to reduce and deposit copper ions at the designated location X. In order to ensure the local thickening effect and the uniformity of the deposited copper layer, the expected thickness can be achieved by controlling the current density (for example, set within the range of 1.0A / dm²-3.0A / dm², preferably 1.5A / dm² or 2.0A / dm²) and the plating time (for example, set within the range of 30 seconds-90 seconds, preferably 50 seconds, 60 seconds or 70 seconds) during electroplating deposition. At the same time, the temperature and stirring speed in the electroplating tank can be precisely controlled to prevent the occurrence of local concentration differences.

[0041] To illustrate with a specific example: an electrolyte consisting of 0.5M copper sulfate and 0.5M sulfuric acid can be selected. Under the conditions of a set current density of 2.0A / dm², a temperature maintained at 25°C, and a stirring speed of about 300 rpm, after 60 seconds of electroplating, a copper layer with a thickness of about 50μm can be deposited at the designated position X. During the entire electroplating deposition process, since deposition is only performed at the designated position X that has been exposed after the controlled depth milling process, unnecessary redundant deposition in other areas is avoided, thereby achieving the precision requirements of local thickening. Through this embodiment, the problem of the difficulty in accurately controlling the thickness of the local copper layer in the traditional process is effectively compensated, and the stability of the electrical contact and heat dissipation performance in the subsequent process is further ensured, providing a solid foundation for improving the performance of high-end electronic devices.

[0042] In one embodiment, the thickness of the locally thickened copper layer Y is determined as follows: Obtaining an electrical characteristic parameter group at the specified position X, wherein the electrical characteristic parameter group includes a target resistance value, a wiring length, a designed line width value, and a copper layer resistivity; Performing process correction on the designed line width according to the etching compensation factor to obtain an actual line width value; The thickness of the locally thickened copper layer Y is obtained according to the target resistance value, the wiring length, the designed line width value, and the resistivity of the copper layer.

[0043] In this embodiment, the target resistance value is the maximum allowable resistance value of the external interconnect device at the specified position X. Specifically, the maximum allowable resistance value can be determined based on the electrical specifications of the external interconnect device (such as a chip). For example, if the maximum allowable voltage V drop is 0.5V, the working current Imax =10A, then the target resistance value =0.1Ω.

[0044] The wiring length is the actual path length of the circuit corresponding to the specified position X in the glass substrate body 1, that is, the actual three-dimensional path length of the circuit at the specified position X, which can be obtained through CAD three-dimensional modeling, optical measurement system or from the design parameters of the glass substrate, and is not limited here.

[0045] The design line width value is a preset line width at a designated position X in the glass substrate body 1 . Specifically, it can be preset according to the high-density wiring requirements of the glass substrate. For example, the preset design line width value is 0.15 mm.

[0046] The resistivity of the copper layer, that is, the resistivity of copper, can be in the range of (1.7~1.8)×10 -8 Ω·m. It should be understood that the resistivity of industrial pure copper (such as electrolytic copper, purity ≥99.9%) is close to the standard value, while the resistivity of copper containing impurities (such as brass) will be higher. However, in the copper layer of electronic circuits (such as PCB copper foil, glass substrate copper wiring), high-purity copper is usually used, so the resistivity can be taken as 1.7×10 -8 Ω·m ~1.8×10 -8 Ω·m is an engineering approximation and is not limited to a specific value.

[0047] The etching compensation factor may range from 1.1 to 2.0, and is not specifically limited thereto.

[0048] As an example, after obtaining the electrical characteristic parameter group of the specified position X, that is, after obtaining the target resistance value, wiring length, design line width value and copper layer resistivity, first, the design line width is corrected by using the etching compensation factor to obtain the actual line width value, that is, the actual line width value can be calculated using formula (1).

[0049] Where W is the actual line width value, is the etching compensation factor, is the design line width value.

[0050] Then, the thickness of the locally thickened copper layer Y can be calculated using formula (2).

[0051] in, is the thickness of the locally thickened copper layer Y, is the target resistance value, is the wiring length, The actual line width value.

[0052] For example, set the design line width value The actual line width is 30μm after etching compensation. 27μm, wiring length The target resistance is 0.1Ω, and the copper layer resistivity is 10mm. Take 1.7×10 -8 Ω·m, then the thickness of the locally thickened copper layer Y can be calculated by formula (2): = 62.96μm, or approximately 63μm (rounded up). To ensure the current-carrying and heat-dissipating capabilities of the glass substrate circuit network, the thickness of the locally thickened copper layer Y is selected to be greater than the calculated thickness. This embodiment ensures the scientific determination of the thickness of the locally thickened copper layer Y, providing an optimized process solution for high-density wiring and high-current-carrying designs on glass substrates.

[0053] In one embodiment, the thickness of the locally thickened copper layer Y may range from 15 μm to 200 μm.

[0054] As an example, when the locally thickened copper layer Y is located in the chip mounting area, the thickness range can be 50μm-200μm; when the locally thickened copper layer Y is used for high-density signal lines, the thickness range can be 15μm-50μm; when the locally thickened copper layer Y is coupled with the heat dissipation through hole, the thickness range can be 80μm-200μm. The specific thickness can be calculated according to the above formula (1) and formula (2), and is not limited here.

[0055] In one embodiment, the cross-sectional area of ​​the locally thickened copper layer Y is determined as follows: According to the actual line width value and the thickness of the locally thickened copper layer Y, the cross-sectional area of ​​the locally thickened copper layer Y is obtained.

[0056] As an example, after the thickness of the locally thickened copper layer Y is calculated, the cross-sectional area of ​​the locally thickened copper layer Y can be further calculated using formula (3).

[0057] in, is the cross-sectional area of ​​the locally thickened copper layer Y, W is the actual line width, and H is the thickness of the locally thickened copper layer Y.

[0058] For example, assuming that after etching compensation, the actual line width W is 27 μm; after electroplating deposition, the thickness H of the locally thickened copper layer Y is 63 μm. The cross-sectional area S of the locally thickened copper layer Y can be calculated as: This method of directly calculating the cross-sectional area based on actual dimensional parameters allows for precise control of the Y deposition process for locally thickened copper layers. This data allows design engineers to verify whether the copper layer can provide sufficient conductive and heat dissipation paths under high-density wiring and high-current conditions, thereby reducing the risk of signal distortion or component failure caused by resistance and local overheating. In other words, it is used to evaluate the current carrying capacity and heat dissipation function of the copper layer in a local area. Generally, the larger the area, the lower the resistance and the better the thermal conductivity, thereby ensuring that the locally thickened area meets the conductivity and heat dissipation requirements required by the design.

[0059] S60 , removing the residual copper foil layer and the conductive adhesive layer on the surface of the composite structure to obtain a glass substrate with a locally thickened copper layer Y.

[0060] As an example, Figure 7 and Figure 8 As shown, removing the residual copper foil layer and the conductive adhesive layer on the surface of the composite structure can be understood as removing the copper foil layer and the conductive adhesive layer in the area Y where no local thickening of the copper layer is required (i.e., the copper foil layer and the conductive adhesive layer except the target copper layer and the electroplated thickening portion thereof).

[0061] Specifically, the residual copper foil layer on the composite structure's surface can be removed first, followed by the residual conductive adhesive layer, to produce a glass substrate with a locally thickened copper layer Y. This embodiment produces a glass substrate that not only has a locally thickened copper layer Y, but also maintains a clean, residue-free non-functional area, meeting the stringent reliability and precision requirements of high-end electronic packaging. Compared to traditional simultaneous removal processes, this phased approach offers significant advantages in accuracy, reliability, and efficiency, making it particularly suitable for the manufacture of advanced glass substrates such as high-density, ultra-thin, and flexible glass substrates.

[0062] In one embodiment, in step S10, the glass substrate body 1 is manufactured by: S11, providing an original glass substrate; S12, performing hole metallization processing on the original glass substrate to form a metallized through-hole structure; S13 , performing conductor circuit patterning on the surface of the original glass substrate after the hole metallization process, to obtain a prepared glass substrate body 1 .

[0063] In this embodiment, the original glass substrate may be a borosilicate glass substrate, an aluminosilicate glass substrate, a quartz glass substrate, or other glass substrates, and its thickness may range from 0.1 mm to 5.0 mm, preferably 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 3.5 mm, or 4.0 mm, without limitation herein. It should be understood that the shape and size of the original glass substrate may be selected as needed and are not limited herein.

[0064] As an example, after selecting the original glass substrate, first, the original glass substrate is subjected to hole metallization treatment, for example, by using a process combining laser drilling or mechanical drilling with chemical copper plating, first drilling a preset through-hole position on the original glass substrate, and then forming a continuous and dense conductive copper layer on the hole wall by electroless deposition, thereby forming a metallized through-hole structure. Next, the surface of the glass substrate on which the metallized through-hole treatment has been completed is subjected to conductor circuit patterning treatment, for example, dry film lithography and acid etching technology can be used, for example, selectively etching the excess copper layer through a photoresist mask to obtain the target circuit pattern. After the above steps, a glass substrate body 1 with a conductor circuit structure and metallized through-holes can be obtained, providing a basic carrier for the subsequent adhesion of the conductive adhesive layer and the copper foil layer and electroplating thickening.

[0065] In one embodiment, the copper foil layer has a thickness ranging from 5 μm to 50 μm, and / or the conductive adhesive layer has a thickness ranging from 15 μm to 100 μm. The specific values ​​can be selected based on actual application requirements. By limiting the thickness of the copper foil layer and the conductive adhesive layer to the above ranges, a balance can be achieved between bonding reliability and subsequent processing accuracy.

[0066] Preferably, the thickness of the copper foil layer may be 10 μm, 20 μm, 30 μm, 35 μm or 40 μm, and the thickness of the conductive adhesive layer may be 20 μm, 35 μm, 50 μm, 65 μm, 75 μm or 90 μm, which are only examples and do not constitute a limitation of the present invention.

[0067] In one embodiment, step S40, i.e., performing a controlled depth milling process on a designated position X of the composite structure to expose a target copper layer in a region where a locally thickened copper layer Y is to be formed on the glass substrate body 1, includes the following steps: S41 , performing one or more controlled-depth milling processes on a designated position X of the composite structure according to a preset milling trajectory and preset depth parameters to expose a target copper layer in an area on the glass substrate body 1 where a local thickened copper layer Y is to be formed.

[0068] In this embodiment, the preset milling trajectory is a path predetermined based on the shape and size of the designated location X. That is, the path data is pre-planned based on the shape (circular, rectangular, or other shape) and size of the designated location X, using computer-aided design (CAD) software to generate the path data. For example, if the designated location X is a rectangular area, the milling trajectory can be generated using computer-aided design (CAD) software to create a straight path that matches the rectangular area based on the boundaries and dimensions of the rectangular area. If the designated location X is a circular area, the milling trajectory can be determined based on the center and radius of the circular area to accurately mill the area.

[0069] The preset depth parameter is a parameter predetermined based on the thickness of the conductive adhesive layer and the copper foil layer. For example, if the copper foil layer is 10 μm thick and the conductive adhesive layer is 50 μm thick, the preset depth parameter may be 60 μm. Here, the preset depth parameter is set only to ensure that the target copper layer at the specified position X on the glass substrate body 1 is not penetrated.

[0070] As an example, Figure 5 As shown, during the milling process, the processing method and processing parameters described in the embodiment of step S40 can be used to perform one or more milling on the conductive adhesive layer and the copper foil layer at the specified position X. For example, if the thickness of the copper foil layer in the composite structure is 25μm and the thickness of the conductive adhesive layer is 60μm, and the target copper layer is at a depth of 85μm from the surface of the composite structure, the preset depth parameter of the controlled depth milling can be set to 85μm, and two milling methods are adopted: the first rough milling to 80μm, and the second fine milling to the final depth of 85μm. During the milling process, the milling depth deviation can be calibrated by real-time detection and feedback to ensure that the surface of the target copper layer is completely exposed. Through this embodiment, not only the problem of local removal that is difficult to achieve with traditional etching is avoided, but also the process flexibility and consistency of the thickening area are significantly improved, providing a clean and controllable metal contact surface for subsequent electroplating thickening, and is suitable for composite structures of various thicknesses and configurations, with good process adaptability and mass production potential.

[0071] In one embodiment, step S60, i.e., removing the residual copper foil layer and the conductive adhesive layer on the surface of the composite structure to obtain a glass substrate having a locally thickened copper layer Y, includes the following steps: S61, removing the residual copper foil layer on the surface of the composite structure by chemical treatment or mechanical treatment to obtain a first-treated composite structure; S62: Using a potassium permanganate solution or a sodium hydroxide solution with a preset concentration to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time, to obtain a glass substrate with a locally thickened copper layer Y.

[0072] In this embodiment, Figure 6 As shown, chemical treatment involves chemical etching (e.g., an acidic ferric chloride solution with a concentration of 15%-25% and an etching rate of 8-15 μm / min) to remove the remaining copper foil on the composite structure's surface. Mechanical treatment involves polishing with a ceramic or flattening brush (e.g., a pressure of 0.01-0.3 MPa and a line speed of 10-20 m / min) to remove the remaining copper foil on the composite structure's surface. It should be understood that chemical treatment is suitable for copper foil layers of 5-20 μm, while mechanical treatment is suitable for copper foil layers of 20-50 μm.

[0073] A potassium permanganate solution or a sodium hydroxide solution of a preset concentration is used to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time. That is, a potassium permanganate solution of a first preset concentration can be used to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time, or a sodium hydroxide solution of a second preset concentration can be used to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time. The first preset concentration can be in the range of 5%-15%, preferably 8% or 11%; the second preset concentration can be in the range of 1%-10%, preferably 5% or 8%. The specific range can be set as needed and is only used as an example. By limiting the concentration range of the potassium permanganate solution and the sodium hydroxide solution, the conductive adhesive layer can be completely dissolved without damaging the glass substrate. This is because a potassium permanganate concentration of less than 5% will not dissolve completely, while a concentration greater than 15% will cause oxidation damage to the glass substrate. A sodium hydroxide concentration of less than 1% is too inefficient, while a concentration greater than 10% will corrode the copper layer.

[0074] As an example, Figure 6 As shown, first, the copper foil layer on the surface of the composite structure can be removed by chemical corrosion or mechanical means. Then, the composite structure after the first treatment is further treated with a potassium permanganate solution or a sodium hydroxide solution of a preset concentration to dissolve the residual conductive adhesive layer. For example, a 5% potassium permanganate solution is used to soak for 10 minutes at 60°C, or a 3% sodium hydroxide solution is used to spray for 5 minutes at room temperature. In actual operation, if the thickness of the conductive adhesive layer is 60μm, an ultrasonic-assisted method can be used to improve the dissolution efficiency, and finally the residual conductive adhesive layer is completely removed to obtain a glass substrate with a locally thickened copper layer Y. Through this embodiment, not only is only the locally thickened copper layer Y located on the original target copper layer retained on the surface of the glass substrate body 1, but a functional glass substrate with a clear structure and stable performance is also obtained.

[0075] In one embodiment, if Figure 7 and Figure 8 As shown, in step S62, that is, using a potassium permanganate solution or a sodium hydroxide solution of a preset concentration to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time to obtain a glass substrate with a locally thickened copper layer Y, the following steps are included: S621, using a potassium permanganate solution or a sodium hydroxide solution of a preset concentration to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time, to obtain a composite structure treated for the second time; S622 , performing plasma desmear treatment on the composite structure processed for the second time, to obtain a glass substrate having a locally thickened copper layer Y.

[0076] As an example, after the conductive adhesive layer on the surface of the composite structure treated for the first time is dissolved by a potassium permanganate solution or a sodium hydroxide solution of a preset concentration, a second-treated composite structure with very little residual micro-contamination can be obtained; further, the dissolved second-treated composite structure needs to be subjected to a plasma decontamination treatment, for example, oxygen plasma and / or argon plasma is used to clean the surface of the second-treated composite structure. Specifically, oxygen (purity ≥ 95%) can be used, power 100W-300W, treatment time 30 seconds-60 seconds, oxygen and / or argon mixed gas (flow ratio 1:1-3:1), power 100W-300W, treatment time 30 seconds-90 seconds, or argon (purity ≥ 95%), power 50W-150W, treatment time 15 seconds-30 seconds, to remove the conductive adhesive residue (particle size > 5μm) on the hole wall and the corners of the complex structure. The particle residue rate is less than 0.05%), so that the organic matter residue on the surface of the glass substrate and the inner wall of the through hole is ≤0.01μg / cm², and the surface roughness Ra is ≤1.0μm. Through this embodiment, step S621 dissolves and removes 80%-90% of the conductive adhesive layer, and step S622 plasma treatment removes the remaining 10%-20% of stubborn residues and drill contamination, with a total removal rate of ≥99.99%. This not only removes extremely small amounts of organic adhesive residue, but also effectively removes particulate contaminants that may be introduced during milling, electroplating, or chemical treatment, ensuring that a glass substrate with a locally thickened copper layer Y is ultimately obtained. This is suitable for microelectronic packaging or high-reliability integrated circuit manufacturing scenarios with high cleanliness requirements, such as glass carriers, glass antennas, or high-frequency and high-speed transmission substrates, and can significantly improve product consistency and stability.

[0077] Second, as Figure 8 As shown, a glass substrate is provided, which is manufactured using the method for manufacturing a glass substrate with a locally thickened copper layer Y according to the first aspect above. The glass substrate includes a locally thickened copper layer Y, and the thickness of the locally thickened copper layer Y is 2 to 10 times the thickness of the copper layer in other areas.

[0078] As an example, the thickness of the locally thickened copper layer Y is 2 to 10 times greater than the thickness of the copper layer in the rest of the glass substrate. Preferably, it can be 5 or 7 times greater, which is not limited here. For example, when the conventional copper layer thickness of the glass substrate is 10 μm, the copper layer thickness in the locally thickened area can be 20 μm to 100 μm. This structural design not only optimizes the thermal resistance and resistance characteristics of the conductive path, but also avoids the cost increase and reduced graphic accuracy caused by the full-thick copper of the traditional glass substrate. It is suitable for application scenarios such as high-density wiring, high-frequency and high-speed signal transmission, and power / ground plane optimization. It is widely used in high-end electronic manufacturing fields such as packaging, MiniLED, and IC substrates.

[0079] It should be understood that the locally thickened copper layer Y includes one or more layers, which can be specifically set as needed and are not limited here.

[0080] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for manufacturing a glass substrate having a locally thickened copper layer, characterized in that: include: providing a glass substrate body; A conductive adhesive layer and a copper foil layer are sequentially stacked on at least one surface of the glass substrate body; Bonding the glass substrate body, the conductive adhesive layer, and the copper foil layer into one body through a hot pressing process to obtain a composite structure; Performing a controlled-depth milling process on a designated position of the composite structure to expose a target copper layer on the glass substrate body where a local thickened copper layer is to be formed; Performing electroplating deposition on the surface of the target copper layer to form a locally thickened copper layer; The residual copper foil layer and the conductive adhesive layer on the surface of the composite structure are removed to obtain a glass substrate with a locally thickened copper layer.

2. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 1, wherein: The glass substrate body is prepared by the following method: Providing raw glass substrates; Performing hole metallization processing on the original glass substrate to form a metallized through-hole structure; Conductor circuit patterning is performed on the surface of the original glass substrate after the hole metallization process is completed to obtain a prepared glass substrate body.

3. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 1, wherein: The conductive adhesive layer includes a first conductive adhesive layer and a second conductive adhesive layer, and the copper foil layer includes a first copper foil layer and a second copper foil layer; The method of sequentially stacking a conductive adhesive layer and a copper foil layer on at least one surface of the glass substrate body comprises: Disposing the first conductive adhesive layer on the first surface of the glass substrate body, and disposing the first copper foil layer on the first conductive adhesive layer; and / or, The second conductive adhesive layer is disposed on the second surface of the glass substrate body, and the second copper foil layer is disposed on the second conductive adhesive layer.

4. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 1, wherein: The thickness of the copper foil layer is 5 μm-50 μm, and / or the thickness of the conductive adhesive layer is 15 μm-100 μm.

5. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 1, wherein: The hot pressing process has a temperature of 75°C-125°C, a pressure of 1.0kgf / cm²-5.0kgf / cm², and a duration of 15 seconds-60 seconds.

6. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 1, wherein: The controlled-depth milling process is performed on a designated position of the composite structure to expose a target copper layer on the glass substrate body where a local thickened copper layer is to be formed, comprising: According to a preset milling trajectory and preset depth parameters, one or more controlled-depth milling processes are performed on a designated position of the composite structure to expose a target copper layer in an area on the glass substrate body where a local thickened copper layer is to be formed; The preset milling trajectory is a path predetermined according to the shape and size of the designated position, and the preset depth parameter is a parameter predetermined according to the thickness of the conductive adhesive layer and the copper foil layer.

7. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 1, wherein: The method of removing the residual copper foil layer and the conductive adhesive layer on the surface of the composite structure to obtain a glass substrate with a locally thickened copper layer comprises: removing the residual copper foil layer on the surface of the composite structure by chemical treatment or mechanical treatment to obtain a first-treated composite structure; A potassium permanganate solution or a sodium hydroxide solution of a preset concentration is used to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time, so as to obtain a glass substrate with a locally thickened copper layer.

8. The method for manufacturing a glass substrate having a locally thickened copper layer according to claim 7, wherein: The method of using a potassium permanganate solution or a sodium hydroxide solution with a preset concentration to dissolve the conductive adhesive layer on the surface of the composite structure treated for the first time to obtain a glass substrate with a locally thickened copper layer comprises: dissolving the conductive adhesive layer on the surface of the composite structure treated for the first time using a potassium permanganate solution or a sodium hydroxide solution with a preset concentration to obtain a composite structure treated for the second time; The composite structure subjected to the second treatment is subjected to plasma desmear treatment to obtain a glass substrate having a locally thickened copper layer.

9. The method for manufacturing a glass substrate having a locally thickened copper layer according to any one of claims 1 to 8, wherein: The thickness of the locally thickened copper layer is determined by: Obtaining an electrical characteristic parameter group for the specified position, the electrical characteristic parameter group including a target resistance value, a wiring length, a designed line width value, and a copper layer resistivity, wherein the target resistance value is a maximum resistance value of an external interconnection device at the specified position, the wiring length is an actual path length of a line corresponding to the specified position in the glass substrate body, and the designed line width value is a preset line width at the specified position in the glass substrate body; Performing process correction on the designed line width according to the etching compensation factor to obtain an actual line width value; The thickness of the locally thickened copper layer is obtained according to the target resistance value, the wiring length, the designed line width value, and the resistivity of the copper layer.

10. A glass substrate having a locally thickened copper layer, characterized in that: The glass substrate is manufactured by the method for manufacturing a glass substrate with a locally thickened copper layer according to any one of claims 1 to 9.

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