A copper filling method, a copper filling device and a copper filling apparatus for a circuit board groove

Abstract

The present application belongs to the technical field of circuit board electroplating hole filling, and particularly relates to a circuit board groove copper filling method, a copper filling device and equipment. The circuit board groove copper filling method comprises the following steps: a first groove with a first depth is opened on a first surface of a circuit board; the first surface is electroplated for the first time, so that the first groove bottom is provided with a first copper plating; a second groove with a second depth is opened on a second surface of the circuit board, the second groove is aligned with the first groove; the second surface is electroplated for the second time, so that the second groove bottom is provided with a second copper plating; the first groove and the second groove are filled with copper; and the sum of the first depth and the second depth is equal to the thickness of the circuit board. The present application realizes the filling of large-aperture through holes with copper, thereby solving the technical problems of incomplete hole filling and uneven copper body on both sides of the through hole in the prior art.

Description

Technical Field

[0001] This invention belongs to the technical field of circuit board electroplating and hole filling, and particularly relates to a method, device and equipment for filling copper in circuit board grooves. Background Technology

[0002] With the rapid iteration of high-end electronic industries such as 5G communication, artificial intelligence, automotive electronics, semiconductor packaging, and high-power power modules, circuit boards are continuously developing towards miniaturization, high-density interconnection, high-frequency and high-speed transmission, high current carrying capacity, high heat dissipation performance, and high reliability. To improve the heat dissipation performance of circuit boards, copper bodies connecting the two sides of the circuit board are usually embedded inside the circuit board to improve the heat conduction capacity of the entire circuit board in a certain area. The main process of this technology is to open through holes in the circuit board and fill the through holes with copper bodies.

[0003] Currently, two main copper-filling processes are used. The first involves creating a through-hole and then pressing the copper material into it. The second involves creating a through-hole and then using a unidirectional pulse to form a copper bridge within the through-hole, effectively turning it into two aligned blind holes. Electroplating is then used to fill these blind holes, creating a through-hole copper material. However, with larger hole diameters (e.g., greater than 6mm), the first technique suffers from unstable pressing and incomplete contact between the copper material and the through-hole, resulting in uneven surfaces. The second technique, when using the unidirectional pulse to create copper bridges, may experience issues such as the copper material collapsing in the middle or incomplete bridging in large holes. In summary, existing copper-filling techniques for large-diameter through-holes often result in incomplete filling and uneven surfaces on both sides of the through-hole. Summary of the Invention

[0004] To address the technical problem of incomplete copper filling and unevenness on both sides of large through-holes in existing technologies, this invention proposes a copper filling method, device, and equipment for circuit board slots.

[0005] The present invention solves the above problems through the following technical solutions: In a first aspect, the present invention proposes a method for filling copper in a circuit board slot, comprising: A first groove of a first depth is formed on the first surface of the circuit board; The first surface is electroplated for the first time so that the bottom of the first tank is plated with copper. A second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; The second surface is electroplated a second time so that the bottom of the second tank is plated with a second copper plating. Fill the first and second tanks with copper; The sum of the depths of the first depth and the second depth is equal to the thickness of the circuit board.

[0006] The copper filling method for circuit board vias involves: creating a first groove of a first depth on the first surface of the circuit board; performing a first electroplating on the first surface to create a first copper plating at the bottom of the first groove; creating a second groove of a second depth on the second surface of the circuit board, aligning the second groove with the first groove; performing a second electroplating on the second surface to create a second copper plating at the bottom of the second groove; and filling the first and second grooves with copper. The sum of the first and second depths is equal to the thickness of the circuit board. This method enables copper filling of large-diameter through-holes, thereby solving the technical problems of incomplete filling and uneven copper on both sides of the through-hole in existing technologies.

[0007] In some embodiments, a first groove of a first depth is formed on a first surface of the circuit board; including: A first groove of a first depth is made on the first surface of the circuit board, the first depth being half the thickness of the circuit board.

[0008] In some embodiments, a second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; including: A second groove with a second depth is formed on the second surface, and a third groove structure extends from the second groove, with the second groove aligned with the first groove.

[0009] In some embodiments, a first electroplating is performed on the first surface to provide a first copper plating at the bottom of the first tank; including: A first film is provided on the first surface, and a first film hole is provided on the first groove, with the first film hole aligned with the first groove; The first surface is electroplated for the first time so that the bottom of the first tank is provided with a first copper plating, the first copper plating having a first thickness.

[0010] In some embodiments, a second electroplating is performed on the second surface to provide a second copper plating at the bottom of the second tank; including: A second film is provided on the second surface, and a second film hole is provided on the second groove, with the second film hole aligned with the second groove; The second surface is electroplated a second time so that the bottom of the second tank is provided with a second copper plating, and the second copper plating has a second thickness.

[0011] In some implementations, the second thickness is less than the first thickness.

[0012] In some embodiments, the first and second tanks are filled with copper; including: A third film is provided on the first surface, and the third film is provided with alignment holes that align with the first groove. A fourth film is provided on the second surface, and the fourth film is provided with alignment holes that align with the second groove. Fill the first and second tanks with copper; Remove the third and fourth films from the first and second surfaces, and grind the copper surfaces of the first and second tanks flat.

[0013] In some embodiments, a second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; further comprising: Test holes are made on the second surface of the circuit board, the test holes are aligned with the first groove, and the test holes extend from the second surface to the first copper plating. A second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove.

[0014] Secondly, the present invention provides a copper-filling device, comprising: The first slotting module is used to create a first slot of a first depth on the first surface of the circuit board. The first electroplating module is used to perform the first electroplating on the first surface so that the bottom of the first tank is provided with the first copper plating. The second slotting module is used to open a second slot of a second depth on the second surface of the circuit board, and the second slot is aligned with the first slot. The second electroplating module is used to perform a second electroplating on the second surface so that the bottom of the second tank is provided with a second copper plating. The third electroplating module is used to fill the first and second tanks with copper.

[0015] Thirdly, the present invention proposes a copper filling device, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other through the communication bus; The memory is used to store at least one executable instruction that causes the processor to perform the operation of the copper filling method for the circuit board slot as described in any of the first aspects.

[0016] The beneficial effects of the copper filling method, copper filling device, and equipment for circuit board slots of the present invention are as follows: By using openings on both sides and secondary electroplating, a copper bridge structure is formed in the through hole. This avoids the problems of copper bridge breakage and failure to form when the copper bridge is formed by laser unidirectional pulse in large-diameter holes. This ensures that the copper bridge is flat and the copper body filled with copper after electroplating is also flat, and also avoids the problem of unstable pressing of the pressed copper body.

[0017] The above description is merely an overview of the technical solutions of the embodiments of the present invention. In order to better understand the technical means of the embodiments of the present invention and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 The flowchart shows steps S1 to S5 of the copper filling method for circuit board slots of the present invention. Figure 2 The flowchart is a process flow chart of steps S51 to S53 of the copper filling method for circuit board slots of the present invention; Figure 3 This is a structural diagram of the copper filling device of the present invention; Figure 4 This is a structural diagram of the copper filling device of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0020] Example 1: like Figures 1-2 As shown in the figure, this embodiment proposes a method for filling copper in circuit board slots, the steps of which include: Step S1: Create a first groove of a first depth on the first surface of the circuit board; Specifically, a first groove of a first depth is formed on the first surface of the circuit board. This can be achieved by routing the first surface of the circuit board using a router method. The first groove is generally a blind via structure. In other embodiments, laser drilling can also be used. Preferably, the first depth should be maintained at about half the width of the circuit board to avoid the problem of one side collapsing and not being fully filled while the other side is filled too thickly during the electroplating process, which would be caused by the depth being too deep or too shallow.

[0021] Step S2: Perform a first electroplating on the first surface to provide a first copper plating at the bottom of the first tank; Specifically, the first surface is electroplated for the first time. This step can be performed separately, or in some other embodiments, it can be performed in conjunction with pattern electroplating, so that the bottom of the first tank is provided with a first copper plating. Preferably, the thickness of the first copper plating is thicker than that of ordinary electroplating, so as to ensure the stability of the copper bridge in the large aperture.

[0022] Step S3: Create a second groove of a second depth on the second surface of the circuit board, and align the second groove with the first groove; Specifically, a second groove of a second depth is formed on the second surface of the circuit board relative to the first surface. This can be achieved by drilling holes into the second surface of the circuit board. The second groove is generally a blind hole structure and needs to be drilled down to connect to the first copper plating. The second groove and the first groove can be exactly the same size for alignment, or they can be different sizes, but they need to have overlapping portions, and these overlapping portions must be aligned so that the copper plating can connect the first and second surfaces.

[0023] Step S4: Perform a second electroplating on the second surface to provide a second copper plating at the bottom of the second tank; Specifically, the second surface undergoes a second electroplating. This step is usually performed separately, or it can be performed simultaneously with the pattern electroplating on the second surface. Through the second electroplating, a second copper plating is applied to the bottom of the two-tank structure, that is, to the side of the first copper plating. This method can stabilize the copper bridge and avoid the technical problems of copper bridge breakage or instability caused by excessively large apertures, which ultimately lead to uneven copper surfaces on both sides and incomplete filling of the holes.

[0024] Step S5: Fill the first and second tanks with copper; wherein the sum of the depths of the first and second tanks is equal to the thickness of the circuit board.

[0025] Specifically, copper is filled into the first and second tanks through electroplating, so that the copper in the first and second tanks can fill the entire blind via. The copper body in the first tank, the first copper plating, the second copper plating, and the copper body in the second tank are connected to form a copper body that penetrates both the first and second surfaces.

[0026] By using openings on both sides and secondary electroplating, a copper bridge structure is formed in the through hole. This avoids the problems of copper bridge breakage and failure to form when the copper bridge is formed by laser unidirectional pulse in large-diameter holes. This ensures that the copper bridge is flat and the copper body filled with copper after electroplating is also flat, and also avoids the problem of unstable pressing of the pressed copper body.

[0027] In some preferred embodiments, a first groove of a first depth is formed on the first surface of the circuit board; including: forming a first groove of a first depth on the first surface of the circuit board, the first depth being half the thickness of the circuit board.

[0028] Specifically, a first groove with a first depth is formed on the first surface. The first depth is half the thickness of the circuit board. Understandably, the second depth is also half the thickness of the circuit board. This method can make the depths of the first and second grooves almost the same. When performing copper filling on both sides of the grooves, it avoids the situation where the copper filling is inconsistent, resulting in incomplete copper filling or a depression in the middle of the first or second groove. Especially in large-size copper filling processes, a groove structure that is too deep is prone to uneven copper filling and depressions, while a groove structure that is too shallow is prone to copper filling protrusions, resulting in an uneven surface.

[0029] In some embodiments, a second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with a first groove; including: the second groove of a second depth is formed on the second surface, the second groove extends with a third groove structure, and the second groove is aligned with the first groove.

[0030] Specifically, a second groove of a second depth is formed on the second surface of the circuit board. The second groove is aligned with the first groove. At the same time, a third groove structure can also be provided. That is, the size of the first groove and the second groove can be the same or different during alignment, but some parts need to be aligned so that after the copper filling is completed, at least some copper body penetrates the first surface and the second surface.

[0031] In some embodiments, a first electroplating is performed on the first surface to provide a first copper plating at the bottom of the first tank; including: A first film is set on the first surface, and a first film hole is set on the first tank body, with the first film hole aligned with the first tank body; the first surface is subjected to a first electroplating, so that a first copper plating is set at the bottom of the first tank body, with the first copper plating having a first thickness.

[0032] Specifically, a first electroplating is performed on the first surface to create a first copper plating at the bottom of the first tank. A first film is provided on the first surface, and a first film hole is formed on the first film. The first film hole is aligned with the opening of the first tank, and can be larger than the opening of the first tank. The first film allows for targeted copper plating inside the first tank, enabling the thickness of the first copper plating to be specifically electroplated according to the desired copper bridge thickness, thus forming the required first copper plating thickness. In some preferred embodiments, the first copper plating is 4 mil. In other embodiments, a film can be provided on the second surface during the first electroplating to prevent the copper thickness on the second surface from becoming too thick.

[0033] In some embodiments, a second electroplating is performed on the second surface to provide a second copper plating at the bottom of the second tank; including: A second film is provided on the second surface, and a second film hole is provided on the second tank body, with the second film hole aligned with the second tank body; a second electroplating is performed on the second surface so that a second copper plating is provided at the bottom of the second tank body, with the second copper plating having a second thickness.

[0034] Specifically, a second electroplating is performed on the second surface to create a second copper plating at the bottom of the second tank. A second film is used on the second surface for targeted electroplating of the second tank. In some preferred cases, a film is also used on the first surface to prevent excessive film thickness within the first tank. The second film has holes aligned with the second tank, allowing for targeted copper plating inside the second tank. This enables the thickness of the second copper plating to be specifically adjusted according to the desired copper bridge thickness. Preferably, the second copper plating is 2 mil.

[0035] In some embodiments, the second thickness is less than the first thickness.

[0036] Specifically, the second thickness is usually thicker to support the entire copper bridge and prevent the copper bridge from breaking when drilling the first copper plating during the second slot drilling, which would result in uneven copper filling on both sides and unevenness on the surface of the slot.

[0037] In some embodiments, filling the first and second tanks with copper includes: Step S51: A third film is provided on the first surface, the third film having alignment holes that align with the first groove body; a fourth film is provided on the second surface, the fourth film having alignment holes that align with the second groove body. Specifically, after the double-sided grooving and electroplating are completed, a third film with alignment holes for the first groove is set on the first surface, and a fourth film with alignment holes for the second groove is set on the second surface. This is to prevent the electroplating layer on the double-sided panel from being too thick due to electroplating in other areas.

[0038] Step S52: Fill the first and second tanks with copper; Specifically, the first and second tanks are filled with copper. This step involves completely filling the first and second tanks with copper. Compared to filling copper directly through through-holes, splitting the process into two opposing blind holes makes it easier to fill the first and second tanks, avoiding the problem of incomplete copper filling in some cavities.

[0039] Step S53: Remove the third and fourth films from the first and second surfaces, and grind the copper surfaces of the first and second tanks flat.

[0040] Specifically, after the copper filling is completed, the film on the first and second surfaces is removed, and both sides are ground flat to achieve a smooth and uniform copper surface on both sides. Compared with the existing technology, which may have 2mil gaps and gaps and a flatness of ±3mil, the existing method achieves a flatness performance of -1mil ±1.5mil for filling large holes, and there are no gaps between the copper block and the substrate.

[0041] In some embodiments, a second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; further comprising: Test holes are made on the second surface of the circuit board, the test holes are aligned with the first groove, and the test holes extend from the second surface to the first copper plating. A second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove.

[0042] Specifically, when creating the second tank, test holes can be made on the second surface first. The test holes are aligned with the first tank and extend to the first copper plating to avoid over-drilling during the routing process.

[0043] Example 2: like Figure 3 As shown, this embodiment proposes a copper filling device, including: The first slotting module 210 is used to perform step S1, which is used to open a first slot of a first depth on the first surface of the circuit board. The first electroplating module 220 is used to execute step S2. Step S2 is used to perform the first electroplating on the first surface after the first grooving module 210 opens the first tank, so that the bottom of the first tank is provided with the first copper plating. The second grooving module 230 is used to perform step S3, which is used to open a second groove of a second depth on the second surface of the circuit board after the first groove of the first surface in step S2 is electroplated for the first time, and the second groove is aligned with the first groove. The second electroplating module 240 is used to perform step S4. After the second tank is slotted in step S3, it is used to perform a second electroplating on the second surface so that the bottom of the second tank is provided with a second copper plating. The third electroplating module 250 is used to perform step S5, which is used to fill the first and second tanks with copper after steps S1-S4 are completed.

[0044] Example 3: like Figure 4 As shown, Figure 4A schematic diagram of embodiment 3 of the copper filling device of the present invention is shown. This specific embodiment does not limit the specific implementation of the copper filling device. The copper filling device may include: a processor 402, a communications interface 404, a memory 406, and a communication bus 408.

[0045] The processor 402, communication interface 404, and memory 406 communicate with each other via communication bus 408. Communication interface 404 is used to communicate with other network elements, such as clients or other servers. The processor 402 executes program 410, specifically performing the relevant steps described in the embodiment of the copper filling method for circuit board slots.

[0046] Specifically, program 410 may include program code, which includes computer-executable instructions.

[0047] Processor 402 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The copper fill device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0048] Memory 406 is used to store program 410. Memory 406 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0049] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system, or other device. Furthermore, the embodiments of this invention are not directed to any particular programming language.

[0050] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. Similarly, for the sake of brevity and to aid in understanding one or more aspects of the invention, in the description of exemplary embodiments of the invention above, various features of the embodiments are sometimes grouped together in a single embodiment, figure, or description thereof. The claims, which follow the detailed description, are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0051] Those skilled in the art will understand that the modules in the device of the embodiment can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiment can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components, except that at least some of such features and / or processes or units are mutually exclusive.

[0052] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.

Claims

1. A method for filling copper into a circuit board slot, characterized in that, include: A first groove of a first depth is formed on the first surface of the circuit board; The first surface is electroplated for the first time so that the bottom of the first tank is provided with a first copper plating. A second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; The second surface is electroplated a second time so that the bottom of the second tank is provided with a second copper plating. Fill the first and second tanks with copper; Wherein, the sum of the depths of the first depth and the second depth is equal to the thickness of the circuit board.

2. The method for filling copper in circuit board slots according to claim 1, characterized in that, The first groove of a first depth is formed on the first surface of the circuit board; including: A first groove of a first depth is formed on the first surface of the circuit board, the first depth being half the thickness of the circuit board.

3. The method for filling copper in circuit board slots according to claim 1, characterized in that, The second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; including: The second surface has a second groove of a second depth, and the second groove extends to a third groove structure, with the second groove aligned with the first groove.

4. The method for filling copper in circuit board slots according to claim 1, characterized in that, The first electroplating of the first surface, so that the bottom of the first tank is provided with a first copper plating, includes: A first film is provided on the first surface, and a first film hole is provided on the first groove, the first film hole being aligned with the first groove; The first surface is electroplated for the first time so that the bottom of the first tank is provided with a first copper plating, the first copper plating having a first thickness.

5. The method for filling copper in circuit board slots according to claim 4, characterized in that, The second electroplating of the second surface, to provide a second copper plating at the bottom of the second tank, includes: A second film is provided on the second surface, and a second film hole is provided on the second groove, the second film hole being aligned with the second groove; The second surface is electroplated a second time so that the bottom of the second tank is provided with a second copper plating, the second copper plating having a second thickness.

6. The method for filling copper in a circuit board slot according to claim 1, characterized in that, The second thickness is less than the first thickness.

7. The method for filling copper in a circuit board slot according to claim 1, characterized in that, The copper filling of the first and second tanks includes: A third film is provided on the first surface, the third film having alignment holes that align with the first groove body; a fourth film is provided on the second surface, the fourth film having alignment holes that align with the second groove body. Fill the first and second tanks with copper; Remove the third and fourth films from the first and second surfaces, and grind the copper surfaces of the first and second tanks smooth.

8. The method for filling copper in a circuit board slot according to claim 1, characterized in that, The second groove with a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove; it also includes: A test hole is formed on the second surface of the circuit board, the test hole is aligned with the first groove, and the test hole extends from the second surface to the first copper plating. A second groove of a second depth is formed on the second surface of the circuit board, and the second groove is aligned with the first groove.

9. A copper-filling device, characterized in that, include: The first slotting module is used to create a first slot of a first depth on the first surface of the circuit board. The first electroplating module is used to perform a first electroplating on the first surface so that the bottom of the first tank is provided with a first copper plating. The second slotting module is used to open a second slot of a second depth on the second surface of the circuit board, and the second slot is aligned with the first slot. The second electroplating module is used to perform a second electroplating on the second surface so that the bottom of the second tank is provided with a second copper plating. The third electroplating module is used to fill the first tank and the second tank with copper.

10. A copper-filling device, characterized in that, include: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation of the copper filling method for circuit board slots as described in any one of claims 1-8.

Images