Method for manufacturing bonding pad of core board and core board
By etching back and micro-etching back the pad pattern, the distance between the pad and the core plate profile is shortened, and the problem of insufficient signal transmission performance in the prior art is solved, and higher signal transmission performance and accuracy are achieved.
Patent Information
- Application Number
- CN202411062609.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2024-12-13
AI Technical Summary
The distance between the existing pad and the core plate shape side is difficult to meet the high requirements for signal transmission performance of high-speed communication products, especially in high-speed communication products above 800G, the signal transmission loss is relatively large.
By obtaining the core plate with pad pattern and eroding it, the distance between the pad pattern and the core plate profile is shortened, ensuring that the molding distance between the target pad and the core plate profile is met with the preset distance, and improving signal transmission performance . The specific steps include obtaining the core plate with the first pad pattern, etching back to form the target pad, or forming the pad pattern by dry film exposure and milling, and micro-etching with an etchant to reach the target distance.
Effectively shorten the distance between the pad pattern and the core plate appearance side, improve the accuracy of the molding distance, reduce signal transmission losses, improve signal transmission performance, and reduce production costs.
Smart Images
Figure CN119136441A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of core board processing, and in particular to a method for manufacturing a solder pad of a core board and a core board. Background Art
[0002] In the design of high-performance optical modules and other high-frequency circuits, there are certain requirements for the distance between the pads and the outer edge of the core board to meet the requirements of signal transmission performance and electrical connection. Including but not limited to bonding pads, input / output pads, power and ground pads, signal pads, thermal pads, RF pads, etc.
[0003] However, in existing solutions, the distance from the pad to the outer edge of the core board, that is, the forming distance, made by methods such as photolithography and laser direct imaging, has been difficult to meet the high requirements of high-speed communication products (not less than 800G) for signal transmission loss.
[0004] Therefore, it is necessary to propose a method for manufacturing a solder pad of a core board to shorten the distance from the solder pad to the outer edge of the core board, thereby improving the signal transmission performance. Summary of the invention
[0005] The main technical problem solved by the present application is to provide a pad manufacturing method and a core board for a core board, which can effectively shorten the distance from the pad pattern to the outer edge of the core board, improve the accuracy of the forming distance, and thus improve the signal transmission performance.
[0006] In order to solve the above technical problems, a technical solution adopted in the present application is: a method for manufacturing a solder pad of a core board, the method comprising:
[0007] Obtaining a core board having a first pad pattern; at least a portion of the edge of the first pad pattern overlaps with an outer edge of the core board;
[0008] The first pad pattern is etched back to form a target pad on the core board; wherein the distance from the target pad to the outer edge of the core board satisfies a preset forming distance.
[0009] Optionally, the step of obtaining a core board having a first pad pattern includes:
[0010] Acquire a core board having a second pad pattern; the second pad pattern extends out of the outer edge of the core board;
[0011] The second pad pattern is milled according to the outer edge of the core board to form the first pad pattern on the core board.
[0012] Optionally, before the step of obtaining the core board having the second pad pattern, the step further includes:
[0013] Determine a pad area on the core board; the pad area includes at least one second pad pattern;
[0014] Using a dry film to cover the pad area, and then exposing the second pad pattern to form the second pad pattern on the core board;
[0015] Optionally, the step of etching back the first pad pattern to form a target pad on the core board includes:
[0016] The dry film is removed, and the first pad pattern is micro-etched back using a preset etchant to form a target pad on the core board.
[0017] Optionally, the second pad pattern extends beyond the outer edge of the core board by 0-100 μm.
[0018] Optionally, a molding distance from the target pad to the outer edge of the core board is 0-50 μm.
[0019] In order to solve the above technical problems, another technical solution adopted by the present application is: a core plate, the core plate comprising:
[0020] A first pad pattern, used for etching back the first pad pattern to obtain a target pad;
[0021] The outer edge of the core board, at least part of the edge of the first pad pattern overlaps with the outer edge of the core board, and the distance from the target pad to the outer edge of the core board meets the preset molding distance.
[0022] Optionally, the core plate further comprises:
[0023] A second pad pattern, the pad pattern extending out of the core board outer shape edge, is used for milling the second pad pattern to obtain the first pad pattern.
[0024] Optionally, the second pad pattern extends beyond the outer edge of the core board by 0-100 μm.
[0025] Optionally, a molding distance from the target pad to the outer edge of the core board is 0-50 μm.
[0026] Optionally, the core board further includes a chip pad, and the chip pad is used to carry a chip.
[0027] The beneficial effect of this embodiment is that, different from the prior art, this embodiment provides a method for making a pad of a core board, the method comprising: obtaining a core board having a first pad pattern; at least part of the edge of the first pad pattern overlaps with the outer edge of the core board; etching back the first pad pattern to form a target pad on the core board; wherein the distance from the target pad to the outer edge of the core board satisfies a preset forming distance. By obtaining a pad pattern that overlaps with the outer edge of the core board and etching back the pad pattern, the distance from the pad pattern to the outer edge of the core board can be effectively shortened, the accuracy of the forming distance can be improved, and the signal transmission performance can be improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a flow chart of the first embodiment of the method for manufacturing the pad of the core board of the present application;
[0029] Figure 2 It is a flow chart of a second embodiment of a method for manufacturing a solder pad of a core board of the present application;
[0030] Figure 3a It is a first schematic diagram of the manufacturing process of the solder pad manufacturing method of the core board of the present application;
[0031] Figure 3b It is a second schematic diagram of the manufacturing process flow of the solder pad manufacturing method of the core board of the present application;
[0032] Figure 3c It is a third schematic diagram of the manufacturing process of the solder pad manufacturing method of the core board of the present application;
[0033] Figure 3d It is a fourth schematic diagram of the manufacturing process of the solder pad manufacturing method of the core board of the present application;
[0034] Figure 3e It is a fifth schematic diagram of the manufacturing process of the solder pad manufacturing method of the core board of the present application;
[0035] Figure 4 It is an exemplary structural block diagram of a manufacturing device 400 for manufacturing a pad of a core board of the present application;
[0036] Figure 5 It is an exemplary structural block diagram of a computer-readable storage medium 500 for making the pads of the core board of the present application.
[0037] Figure numerals: 1 - dry film; 2 - second pad pattern; 3 - copper; 4 - profile machining; 5 - medium; 6 - etchant; 7 - first pad pattern; 8 - molding distance. DETAILED DESCRIPTION
[0038] The present application is described in detail below with reference to the accompanying drawings and implementation methods.
[0039] See also Figure 1 , Figure 1 1 is a flow chart of the first embodiment of the method for making a solder pad of a core board of the present application. It should be noted that if there is substantially the same result, the method of the present application is not limited to the method of making a solder pad of a core board of the present application. Figure 1 The process sequence shown is limited. Figure 1 As shown, the method comprises the following steps:
[0040] Step S110, obtaining a core board having a first pad pattern; at least a portion of the edge of the first pad pattern overlaps with the outer edge of the core board;
[0041] Specifically, this embodiment takes into account that in the design of high-performance optical modules and other high-frequency circuits, there are certain requirements for the distance between the pads and the outer edge of the core board to meet the requirements of signal transmission performance and electrical connection, including but not limited to bonding pads, input / output pads, power and ground pads, signal pads, thermal pads, RF pads, etc.
[0042] In existing solutions, the distance from the pad to the outer edge of the core board made by methods such as photolithography and laser direct imaging is difficult to meet the high requirements of high-speed communication products (not less than 800G) for signal transmission loss. Taking the optical module printed circuit board as an example, its design includes bonding pads and core board pads. As one of the core components of high-speed communication products, the optical module printed circuit board requires that the distance from the bonding pad to the outer edge of the core board be within 50μm to shorten the physical length of the connecting gold wire from the core board pad to the bonding pad, thereby improving the signal transmission performance.
[0043] However, the existing process of controlling the distance through mechanical processing has been unable to meet the distance requirements of high-speed communication products for the bonding pad to the outer edge of the core board. Therefore, the present invention proposes a new innovative method for processing the distance from the pattern to the outer edge of the core board, which can effectively shorten the distance from the bonding pad to the outer edge of the core board, thereby reducing the signal transmission length of the connection between the core board pad and the bonding pad, improving the signal transmission performance, and at the same time, reducing the gold wire loss and reducing the production cost.
[0044] Specifically, the core board can be the basic structural unit of a multi-layer circuit board, and can be composed of one or more layers of insulating material and conductive patterns; the first pad pattern can be an initial pad pattern pre-designed and formed on the core board, for example, it can be a bonding pad, or an input / output pad, a power and ground pad, a signal pad, a thermal pad, a radio frequency pad, etc.; at least part of the edge of the first pad pattern can be a partial boundary or outline of this first pad pattern; the outer edge of the core board can be the physical edge or boundary of the circuit board or chip package, which is used to define the external size and shape of the circuit board or chip package.
[0045] In order to improve the accuracy of controlling the distance between the pad and the outer edge of the core board, a certain margin is left for the first pad graphic during the process construction from the first pad graphic to the outer edge of the core board, so that at least part of the edge of the first pad graphic can be slightly extended or equal in size to the outer edge of the core board, and problems caused by slight changes in the manufacturing process can be avoided, thereby improving the accuracy of precision control.
[0046] The pre-designed first pad pattern can be transferred to the copper foil layer of the core board by pattern transfer technology (such as photolithography technology). The pattern transfer technology can include steps such as coating a photosensitive dry film, exposing, and developing to form the first pad pattern on the core board.
[0047] Step S120, etching back the first pad pattern to form a target pad on the core board; wherein the distance from the target pad to the outer edge of the core board satisfies a preset forming distance.
[0048] Specifically, the etch-back process can be used to erode or wear at least a portion of the edge of the first pad pattern. By eroding or wearing at least a portion of the edge of the first pad pattern by the etch-back method, the molding distance between the first pad pattern and the outer edge of the core board can be processed and controlled with high precision, so that the pad pattern can accurately reach the designed target size and shape.
[0049] The target pad can be used to provide a connection point for the welding of components. After the back etching, the target pad can be the final required pad pattern. The forming distance refers to the distance from the edge of the pad to the outer edge of the core board, and meets the preset tolerance requirements. By etching with an etchant, the distance from the pad pattern to the outer edge of the core board is effectively shortened without increasing the cost, thereby improving the signal transmission performance.
[0050] This embodiment obtains a pad pattern that overlaps with the outer edge of the core board and etches back the pad pattern, thereby effectively shortening the distance from the pad pattern to the outer edge of the core board, improving the accuracy of the forming distance, and further improving the signal transmission performance.
[0051] See also Figure 2 , Figure 2 1 is a flow chart of a second embodiment of a method for making a pad of a core board of the present application. In this embodiment, the method comprises the following steps:
[0052] Step S201, determining a pad area on a core board; the pad area includes at least one second pad pattern;
[0053] This embodiment takes into account that the distance from the bonding pad of the core board to the outer edge of the core board for high-speed communication products is required to be within 50μm. However, the existing process is difficult to meet the requirements of high-speed communication products through the control of mechanical processing accuracy. Therefore, this embodiment can reduce the difficulty of pattern and mechanical shape alignment by combining pattern alignment with mechanical shape processing. At the same time, the distance between the first pad pattern and the board edge is controlled by etching with an etchant, which can effectively achieve the distance from the pad pattern to the board edge without increasing the production cost, thereby improving the signal transmission performance.
[0054] Specifically, the core board may be a copper clad board, which is a basic material for manufacturing printed circuit boards, and the structure of the core board may be copper-substrate-copper; the pad area may include at least one second pad pattern.
[0055] Step S202, using a dry film to cover the pad area, and then exposing the second pad pattern to form the second pad pattern on the core board;
[0056] Specifically, the dry film is used to coat the surface of the core board, and by exposing and developing the pad area, at least one second pad pattern in the pad area can be transferred to the core board; wherein the dry film can not only be used to expose the second pad pattern, but also serve as a protective layer for the second pad pattern.
[0057] Furthermore, the core board also includes a chip pad, and the chip pad is used to carry the chip.
[0058] Step S210, obtaining a core board having a second pad pattern; the second pad pattern extends out of the outer edge of the core board;
[0059] Specifically, because the pad pattern after actual processing is designed to be inside the core board instead of being directly located at the edge, the edge of the pad pattern designed on the core board in the existing solution is generally smaller than the outer edge of the core board.
[0060] However, in this embodiment, the pad pattern can exceed the outer edge of the core board when being designed, that is, a portion of the initial second pad pattern extends out of the outer edge of the core board, and the extended portion is used for buffering, so that it can be accurately aligned and processed to the pad pattern during the subsequent mechanical milling process without causing processing errors of the pad pattern due to position offset.
[0061] Furthermore, the second pad pattern extends out of the outer edge of the core board by 0-100 μm.
[0062] Specifically, considering that in the actual manufacturing process, etching, exposure, development and other process steps may cause slight dimensional deviations, this embodiment takes the extension range of 0-100μm as an example. This range can tolerate slight errors that may occur in the manufacturing process while ensuring the welding quality and electrical performance. As a result, precise control of the distance from the pad pattern to the core board outer edge with high reliability can be achieved.
[0063] Step S220, milling the second pad pattern according to the outer edge of the core board to form the first pad pattern on the core board;
[0064] Specifically, the process of forming the desired shape by cutting or removing material. In manufacturing the core board, at least part of the edge of the second pad pattern can be milled according to the edge of the core board shape to obtain the first pad pattern of the desired size and shape.
[0065] Step S230, removing the dry film, and using a preset etchant to micro-etch back the first pad pattern to form a target pad on the core board.
[0066] Specifically, micro-etching back can be a fine etching retraction process for correcting or adjusting the shape and size of the first pad pattern and the wire. The etchant can be a chemical etching solution or micro-etching solution of a specific formula for controlling the accuracy and effect of the etch back. The etchant is used to finely erode at least a portion of the edge of the first pad pattern to adjust the size or shape of the first pad pattern to obtain a target pad.
[0067] Furthermore, the molding distance from the target pad to the outer edge of the core board is 0-50 μm.
[0068] Specifically, this embodiment takes the process of disassembling the mSAP process and making improvements based on the process as an example to meet the high-speed communication requirements where the distance from the pad pattern to the core board outer edge is less than or equal to 50 μm. In other embodiments, it can also be a SAP process, an LDI process, or an SLP process, which is not limited in this embodiment.
[0069] See also Figures 3a to 3e , Figures 3a to 3e It is a flow chart of the third embodiment of the method for manufacturing the solder pad of the core board of the present application.
[0070] First, see Figure 3a , Figure 3a This is the first schematic diagram of the manufacturing process of the solder pad manufacturing method of the core board of the present application. Figure 3a It is shown that the dry film 1 covers the entire pad area, wherein the pad area includes at least one second pad pattern 2. This embodiment takes the pad area including three second pad patterns 2 as an example;
[0071] Then, see Figure 3b , Figure 3b It is a second schematic diagram of the manufacturing process of the pad manufacturing method of the core board of the present application, by exposing and processing the second pad pattern 2 to transfer the second pad pattern 2 to the core board, and copper 3 is plated on the surface of the entire core board;
[0072] Then, see Figure 3c , Figure 3c This is the third schematic diagram of the manufacturing process flow of the solder pad manufacturing method of the core board of the present application. Figure 3c As shown, the second pad pattern 2 can extend 0-100 μm beyond the outer edge of the core board, so that when the outer edge machining 4 performs milling on the second pad pattern 2, the milled pad pattern can overlap with the outer edge of the core board.
[0073] Then, see Figure 3d , Figure 3d This is the fourth schematic diagram of the manufacturing process flow of the solder pad manufacturing method of the core board of the present application. Figure 3d The first pad pattern 7 obtained by milling when the second pad pattern 2 extends beyond the outer edge of the core board is shown, and at least a portion of the edge of the first pad pattern 7 overlaps with the outer edge of the core board.
[0074] Finally, see Figure 3e , Figure 3e The fifth schematic diagram of the manufacturing process of the pad manufacturing method of the core board of the present application is shown in FIG. The dry film 1 is removed to expose the dielectric 5 on the core board, and the first pad pattern 7 is micro-etched back using a micro-etching etchant 6 to obtain the following: Figure 3e The forming distance 8 shown, that is, the distance between the pad and the outer edge of the core board, can control the distance from the pad to the outer edge of the core board within the range of 0-50μm, which can improve the accuracy of the forming distance and thus improve the signal transmission performance.
[0075] See also Figure 4 , Figure 4 FIG. 4 is an exemplary structural block diagram of a manufacturing device 400 for manufacturing a pad of a core board according to this embodiment. Figure 4 As shown in , the manufacturing device 400 of the present application may include a processor 401 and a memory 402, wherein the processor 401 and the memory 402 communicate with each other via a bus. The memory 402 stores program instructions for making pads of a core board. When the program instructions are executed by the processor 401, the method steps described in the above text in combination with the accompanying drawings are implemented: obtaining a core board having a first pad pattern; at least part of the edge of the first pad pattern overlaps with the outer edge of the core board; etching back the first pad pattern to form a target pad on the core board; wherein the distance from the target pad to the outer edge of the core board meets the preset molding distance.
[0076] Optionally, the processor 401 executes the step of obtaining a core board having a first pad pattern, including:
[0077] Acquire a core board having a second pad pattern; the second pad pattern extends out of the outer edge of the core board;
[0078] The second pad pattern is milled according to the outer edge of the core board to form the first pad pattern on the core board.
[0079] Optionally, before the processor 401 executes the step of acquiring the core board having the second pad pattern, the process further includes:
[0080] Determine a pad area on the core board; the pad area includes at least one second pad pattern;
[0081] Using a dry film to cover the pad area, and then exposing the second pad pattern to form the second pad pattern on the core board;
[0082] Optionally, the processor 401 performs the step of etching back the first pad pattern to form a target pad on the core board, including:
[0083] The dry film is removed, and the first pad pattern is micro-etched back using a preset etchant to form a target pad on the core board.
[0084] Optionally, the processor 401 executes the second pad pattern to extend out of the outer edge of the core board by 0-100 μm.
[0085] Optionally, the processor 401 executes a forming distance from the target pad to the outer edge of the core board of 0-50 μm.
[0086] See also Figure 5 , Figure 5 This is an exemplary structural block diagram of a computer-readable storage medium 500 for making a pad for a core board according to an embodiment of the present application. The computer-readable storage medium 500 stores a computer program 501, and when the computer program 501 is run on a computer, the computer executes the above-mentioned related method steps to implement a pad making method for a core board in the above-mentioned embodiment.
[0087] The present application also provides a core board, the core board comprising:
[0088] A first pad pattern, used for etching back to form a target pad on the core board;
[0089] The outer edge of the core board, at least part of the edge of the first pad pattern overlaps with the outer edge of the core board, and the distance from the target pad to the outer edge of the core board meets the preset molding distance.
[0090] Furthermore, the core plate further comprises:
[0091] A second pad pattern, the pad pattern extending out of the core board outer shape edge, is used for milling the second pad pattern to obtain the first pad pattern.
[0092] Furthermore, the second pad pattern extends out of the outer edge of the core board by 0-100 μm.
[0093] Furthermore, the molding distance from the target pad to the outer edge of the core board is 0-50 μm.
[0094] Furthermore, the core board also includes a chip pad, and the chip pad is used to carry the chip.
[0095] The above scheme is to obtain a core board with a first pad pattern; at least part of the edge of the first pad pattern overlaps with the outer edge of the core board; the first pad pattern is etched back to form a target pad on the core board; wherein the distance from the target pad to the outer edge of the core board meets the preset forming distance. By obtaining a pad pattern that overlaps with the outer edge of the core board and etching back the pad pattern, the distance from the pad pattern to the outer edge of the core board can be effectively shortened, the accuracy of the forming distance can be improved, and the signal transmission performance can be improved.
[0096] In the several embodiments provided in the present application, it should be understood that the disclosed methods, manufacturing equipment and storage media can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
[0097] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.
[0098] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.
[0099] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.
[0100] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A method for manufacturing a solder pad of a core board, characterized in that: The method comprises: Obtaining a core board having a first pad pattern; at least a portion of the edge of the first pad pattern overlaps with an outer edge of the core board; The first pad pattern is etched back to form a target pad on the core board; wherein the distance from the target pad to the outer edge of the core board satisfies a preset forming distance.
2. The method according to claim 1, characterized in that: The step of obtaining a core board having a first pad pattern comprises: Acquire a core board having a second pad pattern; the second pad pattern extends out of the outer edge of the core board; The second pad pattern is milled according to the outer edge of the core board to form the first pad pattern on the core board.
3. The method according to claim 2, characterized in that Before the step of obtaining the core board having the second pad pattern, the method further comprises: Determine a pad area on the core board; the pad area includes at least one second pad pattern; Using a dry film to cover the pad area, and then exposing the second pad pattern to form the second pad pattern on the core board; The step of etching back the first pad pattern to form a target pad on the core board comprises: The dry film is removed, and the first pad pattern is micro-etched back using a preset etchant to form a target pad on the core board.
4. The method according to claim 2, characterized in that The second pad pattern extends out of the outer edge of the core board by 0-100 μm.
5. The method according to claim 1, characterized in that The molding distance from the target pad to the outer edge of the core board is 0-50 μm.
6. A core board, characterized in that: The core plate comprises: A first pad pattern, used for etching back to form a target pad on the core board; The outer edge of the core board, at least part of the edge of the first pad pattern overlaps with the outer edge of the core board, and the distance from the target pad to the outer edge of the core board meets the preset molding distance.
7. The core plate according to claim 6, characterized in that: The core plate also includes: A second pad pattern, the pad pattern extending out of the core board outer shape edge, is used for milling the second pad pattern to obtain the first pad pattern.
8. The core plate according to claim 7, characterized in that: The second pad pattern extends out of the outer edge of the core board by 0-100 μm.
9. The core plate according to claim 6, characterized in that: The molding distance from the target pad to the outer edge of the core board is 0-50 μm.
10. The core plate according to claim 6, characterized in that: The core board also includes a chip pad, and the chip pad is used to carry a chip.