Manufacturing method of thermoelectric separation PCB

Abstract

The invention discloses a manufacturing method of a thermoelectric separation PCB, and the method comprises the following steps: providing a core board, carrying out the windowing of the core board, and forming a core board window; providing prepregs and copper foils, sequentially stacking the prepregs and the copper foils on two sides of the core plate, performing vacuum lamination, filling the core plate with the prepregs, opening the window, pressing the plate, and punching a target hole; drilling a via hole in an area corresponding to the windowing of the core plate; copper deposition is carried out, so that the via holes are metalized, a layer of thin copper is deposited on the plate surface, the thickness of the thin copper is 0.5-0.8 [mu] m, and the thickness of a copper layer on the hole walls of the via holes is larger than or equal to 25 [mu] m; a dry film is pasted on the board surface, secondary windowing is conducted on the windowing area of the core board, and the pattern of the secondary windowing is made to be consistent with the pattern of the windowing of the core board; performing vacuum resin hole plugging and ceramic grinding; copper deposition and electroplating: plating a layer of copper on the resin for secondary windowing above the via hole and forming a boss, and connecting the boss with the hole wall copper layer; and grinding the plate surface. According to the manufacturing method of the thermoelectric separation PCB, the heat dissipation performance of the PCB substrate can be improved.

Description

Technical Field

[0001] This invention relates to the field of circuit board manufacturing technology, and specifically to a method for manufacturing a thermoelectrically separated PCB. Background Technology

[0002] Metal substrates are composite materials that combine metal materials and insulating layers through a special process. They possess the high thermal conductivity of metals and the electrical insulation properties of insulating materials, and are widely used in electronics, communications, power and other fields.

[0003] Currently, PCBs in the industry, such as copper / aluminum glue-coated aluminum substrates, copper substrates, and other composite substrates, are designed to meet the requirements of electrical conductivity wiring. However, the heat generated by the devices during operation is blocked by the insulating adhesive underneath, preventing it from being effectively conducted to the heat sink below. This affects the heat dissipation performance of the PCB, thus impacting its application in high-power-density electronic devices (such as communication power supplies and automotive electronics).

[0004] Therefore, the purpose of this invention is to provide a manufacturing process for a thermoelectrically separated PCB to solve the problem of poor heat dissipation performance of the substrate. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for manufacturing a thermoelectrically separated PCB, which can improve the heat dissipation performance of the PCB substrate.

[0006] The technical solution of this invention is:

[0007] A method for manufacturing a thermoelectrically separated PCB includes the following steps:

[0008] Step S1: Provide a core board and perform a windowing process on the core board to form a core board window.

[0009] Step S2: Provide prepreg and copper foil, stack the prepreg and copper foil on both sides of the core board in sequence, and perform vacuum lamination. The prepreg fills the opening in the core board, and punches target holes after pressing.

[0010] Step S3: Drill through holes in the area corresponding to the window opening in the core board;

[0011] Step S4, copper plating, to metallize the vias and deposit a thin copper layer on the board surface with a thickness of 0.5-0.8 μm, and the copper layer thickness on the via wall is ≥25 μm;

[0012] Step S5: Apply dry film to the board surface and perform secondary windowing in the core board windowing area corresponding to the top copper foil, so that the secondary windowing pattern is consistent with the core board windowing pattern.

[0013] Step S6: Vacuum resin plugging and ceramic grinding are performed to ensure that the resin above the via is at the same height as the top copper foil and that there is no resin residue on the top copper foil.

[0014] Step S7, copper plating, to form a thin copper layer of 0.5-0.8um thickness on the resin above the secondary window above the via;

[0015] Electroplating: A low-current, long-time electroplating method is used to plate a layer of copper onto the resin with secondary openings above the through hole to form a boss. The boss is connected to the copper layer on the hole wall.

[0016] Step S8: Grind the surface of the board.

[0017] Furthermore, the height of the boss above the board surface is 165±30um.

[0018] Furthermore, the core board is a 2OZ single-layer board.

[0019] Furthermore, the diameter of the through hole is 0.2-0.3 mm.

[0020] Compared with the prior art, the thermoelectric separation PCB manufacturing method provided by the present invention has the following advantages:

[0021] The method for manufacturing a thermoelectrically separated PCB provided by this invention involves drilling through holes at positions corresponding to the openings in the substrate and the core board, forming a copper layer on the hole wall through a copper plating process, and electroplating bosses on the board surface. The bosses are connected to the copper layer on the hole wall to form a vertically downward heat conduction channel, which efficiently and quickly conducts the heat generated by the circuit board to the heat sink, thereby improving the heat dissipation performance of the PCB substrate. By increasing the heat conduction channel, the mutual interference between electrical conduction and thermal conduction is avoided, ensuring a balance of thermoelectric performance.

[0022] II. The method for manufacturing a thermoelectrically separated PCB provided by the present invention forms copper bosses on the board surface, which can be used as soldering planes. During the reflow soldering process, the temperature change in the boss area is more gradual, which helps the solder paste to fully melt and wet, forming high-quality solder joints and reducing cold solder joints.

[0023] Third, the method for manufacturing a thermoelectrically separated PCB provided by this invention allows the PCB to be widely used in various electronic products with stringent requirements for heat dissipation and reliability. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic flowchart of the manufacturing method of the thermoelectric separation PCB of the present invention;

[0026] Figure 2 This is a schematic diagram of the thermoelectric separation PCB obtained by the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described below.

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] Please see Figure 1 This is a schematic flowchart of the method for manufacturing the thermoelectrically separated PCB of the present invention. The method for manufacturing the thermoelectrically separated PCB of the present invention includes the following steps:

[0030] Step S1: Provide a core board and perform a windowing process on the core board to form a core board window.

[0031] The core board can be copper-based or aluminum-based; in this embodiment, it is a 2OZ single-sided aluminum substrate.

[0032] The windowing method is as follows: Apply a dry film to the core board with a thickness of 40µm; expose and cure the copper-free side as a whole, and expose the copper side according to the windowing pattern; develop to reveal the pattern on the copper side; remove the film. In this way, a window is formed on the copper side of the single-sided aluminum-based core board.

[0033] Step S2: Provide prepreg and copper foil, stack the prepreg and copper foil on both sides of the core board in sequence, and perform vacuum lamination. The prepreg fills the opening in the core board, and punches target holes after pressing.

[0034] The two prepreg sheets are defined as the first prepreg sheet and the second prepreg sheet, respectively, and the two copper foils are defined as the bottom copper foil and the top copper foil, respectively. The bottom copper foil is distributed on the bottom surface of the core board, and the top copper foil is distributed on the top surface of the core board.

[0035] Step S3: Drill through holes in the area corresponding to the window opening in the core board;

[0036] The drilling process is as follows: following the drilling method for multilayer boards, first drill pin holes on the drilling machine table, insert pins, fit the punched circuit board into the pin holes, and drill through holes in the area corresponding to the window opening on the core board according to the manufacturing data; preferably, the diameter of the through holes is 0.2-0.3mm.

[0037] Step S4, copper plating, to metallize the vias and deposit a thin copper layer on the board surface with a thickness of 0.5-0.8um;

[0038] Specifically, a high-copper, low-acid electroplating solution is used, and a low-current, long-time electroplating method is employed for hole plating to form a copper layer on the hole wall, with the thickness of the copper layer controlled at ≥25um.

[0039] Step S5: Apply dry film to the board surface and perform secondary windowing in the core board windowing area corresponding to the top copper foil, so that the secondary windowing pattern is consistent with the core board windowing pattern.

[0040] Step S6: Vacuum resin plugging and ceramic grinding are performed to ensure that the resin above the via is at the same height as the top copper foil and that there is no resin residue on the top copper foil.

[0041] Step S7, copper plating, to form a thin copper layer of 0.5-0.8um thickness on the resin above the secondary window above the via;

[0042] Electroplating: A low-current, long-time electroplating method is used to plate a layer of copper onto the resin with secondary openings above the through hole to form a boss. The boss is connected to the copper layer on the hole wall.

[0043] In this embodiment, the height of the boss above the plate surface is 165±30um;

[0044] Step S8: Grind the board surface to make it smooth. Specifically, use 1200-grit sandpaper to sand the board surface to remove surface oxides.

[0045] The method for manufacturing a thermoelectrically separated PCB of the present invention produces a thermoelectrically separated PCB structure as follows: Figure 2 As shown. The thermoelectric separation PCB of the present invention includes a substrate 1 formed by laminating a bottom copper foil 11, a first prepreg 12, a core board 13 with an opening 131, a second prepreg 14 and a top copper foil 15 in sequence; a filler layer 2 filled in the opening 131; a through hole 3 formed corresponding to the opening position and penetrating the substrate; a hole wall copper layer 4 formed on the hole wall of the through hole 3 by a copper plating process; and a boss 5 formed on the surface of the top copper foil by a copper plating and electroplating process, wherein the hole wall copper layer 4 is connected to the boss 5. The filler layer 2 is formed by filling the opening 1 through the first prepreg and the second prepreg after melting during the lamination process.

[0046] In this embodiment, the core board is a 2OZ single-layer board; the shape of the boss 5 is consistent with the shape of the window 131, and the height of the boss 5 above the top copper foil is 165±30um; the diameter of the through hole is 0.2-0.3mm; the thickness of the copper layer 4 on the hole wall is ≥25um.

[0047] In this embodiment, there are multiple through holes, which can improve the heat conduction effect.

[0048] The method for manufacturing a thermoelectrically separated PCB provided by this invention involves drilling through holes at the opening positions of the core board, forming a copper layer on the hole wall through a copper plating process, and electroplating bosses on the board surface. The bosses are connected to the copper layer on the hole wall to form a vertically downward heat conduction channel, which efficiently and quickly conducts the heat generated by the circuit board to the heat sink, thereby improving the heat dissipation performance of the PCB substrate. By increasing the heat conduction channel, the mutual interference between electrical conduction and thermal conduction is avoided, ensuring a balance of thermoelectric performance.

[0049] The thermoelectric separation PCB of this invention can be widely used in various electronic products with stringent requirements for heat dissipation and reliability, such as communication power supplies and automotive electronic products.

[0050] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A method of manufacturing a thermoelectrically separated PCB, characterized by, The method comprises the following steps: S1, providing a core plate, and performing windowing processing on the core plate to form a core plate window; S2, providing a prepreg and a copper foil, and sequentially stacking the prepreg and the copper foil on both sides of the core plate, and performing vacuum lamination, the prepreg filling the core plate window, and punching a target hole after pressing the plate; S3, drilling a through hole in a region corresponding to the core plate window; S4, copper deposition, metalizing the through hole, and depositing a thin copper layer on the plate surface, the thickness of the thin copper layer being 0.5-0.8 um, and the thickness of the copper layer on the wall of the through hole being ≥25 um; S5, pasting a dry film on the plate surface, and performing secondary windowing on a region of the core plate corresponding to the top copper foil, so that the secondary windowing is consistent with the pattern of the core plate window; S6, vacuum resin hole plugging and ceramic grinding, so that the resin above the through hole is consistent in height with the top copper foil, and there is no resin residue on the top copper foil; S7, copper deposition, forming a 0.5-0.8 um thick thin copper layer on the resin of the secondary windowing above the through hole; electroplating, using a small current long time electroplating method to plate a copper layer on the resin of the secondary windowing above the through hole and form a boss, the boss being connected with the copper layer on the wall of the hole; S8, grinding the plate surface.

2. The method of claim 1, wherein, The height of the boss above the plate surface is 165±30 um.

3. The method of claim 1, wherein the heat-dissipating PCB is manufactured by a process comprising: The core plate is a 20Z single-layer plate.

4. The method of claim 1, wherein the heat-dissipating PCB is manufactured by a process comprising: The aperture of the through hole is 0.2-0.3 mm.

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