A method for manufacturing a buried small-pitch thin copper-based PCB board

Abstract

The embodiment of the present invention discloses a method for manufacturing a PCB board with a small-pitch embedded thin copper base, the method comprising laser cutting to cut out the copper base shape, laminating to press the thin copper base to be embedded into the core board, resin plugging to fill the spacing position formed on the copper base with resin, laser cutting to remove the copper base connection position, and laminating to complete the pressing. The present invention effectively avoids the problems of lack of glue, board warping, and uneven dielectric thickness in the embedding process of the thin copper base plate with a copper base thickness of ≤0.8mm, and achieves the effect of manufacturing an embedded thin copper base plate with a small pitch.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit board processing, and in particular to a method for manufacturing an embedded small-pitch thin copper-based PCB, wherein the PCB is mainly used for a BMS battery management system of an electric vehicle. Background Art

[0002] With the rapid development of new energy electric vehicles, the demand for PCBs for high-current and high-voltage batteries has also grown rapidly. Since the PCBs used in electric vehicle power batteries and BMS battery management systems need to carry high currents and high voltages, copper blocks need to be embedded in the PCBs. However, most of the currently embedded copper blocks are thick copper bases with a thickness greater than 1.5 mm. For thin copper bases with a thickness of ≤0.8 mm, the conventional method of thick copper bases will result in quality problems such as lack of glue, board warping, and uneven dielectric thickness. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for manufacturing an embedded small-pitch thin copper-based PCB board to solve the problems of lack of glue, board warping and uneven dielectric thickness during the embedding process of the thin copper substrate with a copper base thickness of ≤0.8mm.

[0004] In order to solve the above technical problems, the object of the present invention is to achieve the following technical solutions: to provide a method for manufacturing an embedded small-pitch thin copper-based PCB board, comprising:

[0005] The first laser cutting is to cut out the required copper base shape and connection positions through the first laser cutting;

[0006] The first pressing is to embed the copper base after the first laser cutting into the core board and then press it;

[0007] The first resin buried groove is filled with vacuum resin at the spacing position formed on the copper base after the first laser cutting;

[0008] A second laser cutting, wherein the copper-based connection position is cut off by the second laser cutting;

[0009] The second resin filling groove is used to fill the connection position after the second laser cutting with vacuum resin, and the resin is baked and smoothed;

[0010] The second lamination is performed from top to bottom in the order of the first copper foil, the first PP, the core board, the second PP, and the second copper foil.

[0011] Furthermore, the first laser cutting includes:

[0012] Select a FR4 epoxy resin board and a copper base with a thickness of ≤0.8mm, and stick a high-temperature protective film on the copper base. Then, cover the copper base on the FR4 epoxy resin board and bury the grooves according to the pre-designed pattern to retain the connection positions between different network copper blocks on the copper base for laser cutting to obtain the required copper base shape and connection positions.

[0013] Furthermore, in the first laser cutting, the dimensional tolerance of the copper block is +0.05 mm / -0.1 mm, and the copper block is acid-etched for deburring at 7 m / min with one etching cylinder; the copper base thickness is the required thickness + 0.1 mm.

[0014] Furthermore, auxiliary connection positions are designed at intervals of 50 mm between the connection positions.

[0015] Furthermore, the core board is a core board with a high temperature protection film and an electric milling groove for embedding the copper-based electric milling groove.

[0016] Furthermore, the first resin-filling groove includes: vacuum-filling the spacing position formed on the copper base after the first laser cutting with resin, and correspondingly baking and stripping off the high-temperature protective film on the copper base and the core board.

[0017] Furthermore, the second laser cutting includes: cutting off the copper-based connection positions by the second laser cutting, and then filling the original connection positions on the copper base with resin to achieve connection between different network copper blocks on the copper base.

[0018] Compared with the prior art, the present invention uses a laser cutting to cut out the copper base shape, a lamination to press the thin copper base to be buried into the core board, a resin plugging groove to fill the spacing position formed on the copper base with resin, a second laser cutting to remove the copper base connection position, and a second lamination to complete the pressing. The method described in the present invention effectively avoids the problems of lack of glue, board warping, and uneven dielectric thickness in the embedding process of the thin copper substrate with a copper base thickness of ≤0.8mm, and achieves the effect of embedding a small-pitch thin copper substrate. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0021] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0022] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0023] Example 1

[0024] The present embodiment provides a method for manufacturing a buried small-pitch thin copper-based PCB board, comprising: a first laser cutting; a first pressing; a first resin buried groove plugging; a second laser cutting; a second resin buried groove plugging; and a second lamination.

[0025] Among them, the first laser cutting includes: first selecting an FR4 epoxy resin board and a copper base with a thickness of ≤0.8mm (the thickness of the copper base in this embodiment is the required thickness + 0.1mm), then sticking a high-temperature protective film on the copper base, and then covering the copper base on the FR4 epoxy resin board and burying grooves according to a pre-designed pattern to retain the connection positions between different network copper blocks on the copper base for the first laser cutting to obtain the required copper base shape and connection positions, and the corresponding connection positions formed on the obtained copper base are also designed with auxiliary connection positions at intervals of 50mm.

[0026] In this embodiment, the first laser cutting was performed, and the size tolerance of the copper block was +0.05 mm / -0.1 mm. The copper block was acid-etched to remove burrs at 7 m / min with one etching cylinder.

[0027] The first lamination includes: firstly, the core board with the high temperature protection film is electrically milled to mill out the required grooves for embedding the copper base after the first laser cutting; and then, the copper foil, PP and the core board embedded with the copper base are laminated.

[0028] The first resin filling groove includes: vacuum filling the spacing position formed on the copper base after the first laser cutting with resin, and correspondingly baking and peeling off the high temperature protective film on the copper base and the core board. Since the first pressing PP will partially flow into the spacing position, but the amount is small, it is necessary to fill the spacing position with resin by vacuum filling.

[0029] The second laser cutting comprises: cutting off the copper base connection position by the second laser cutting, and then filling the original connection position on the copper base with resin to achieve the connection between different network copper blocks on the copper base.

[0030] The second resin-filling groove includes: vacuum-filling the connection position after the second laser cutting with resin, then baking it, and correspondingly grinding the resin.

[0031] The second lamination is performed from top to bottom in the manner of first copper foil, first PP, core board, second PP, and second copper foil. The second PP is a high thermal conductivity PP.

[0032] In summary, the present invention uses a laser cutting to cut out the copper base shape, a lamination to press the thin copper base to be buried into the core board, a resin plugging groove to fill the spacing position formed on the copper base, a second laser cutting to remove the copper base connection position, and a second lamination to complete the pressing. The above method achieves the effect of embedding a small-pitch thin copper substrate, and eliminates the quality problems such as lack of glue, board warping, and uneven dielectric thickness caused by the conventional method of embedding a small-pitch thin copper base.

[0033] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for manufacturing a buried small-pitch thin copper-based PCB board, characterized in that: include: For the first laser cutting, a FR4 epoxy resin board and a copper base with a thickness of ≤0.8 mm are selected, a high temperature protective film is pasted on the copper base, and then the copper base is covered on the FR4 epoxy resin board and the connection positions between different network copper blocks on the copper base are retained according to the pre-designed pattern. The first laser cutting is performed to obtain the required copper base shape and connection positions. Auxiliary connection positions are also designed at 50 mm intervals corresponding to the connection positions formed on the obtained copper base; In the first lamination, the core board with high temperature protective film is milled with electric milling to mill out the required grooves for embedding the copper base after the first laser cutting, and then the copper foil, PP and the core board embedded with copper base are pressed together; The first resin-filled slot is filled with vacuum resin at the spacing position formed on the copper base after the first laser cutting, and the high-temperature protective film on the copper base and core board is baked and peeled off accordingly; The second laser cutting is to cut off the copper base connection position through the second laser cutting, and then fill the original connection position on the copper base with resin to achieve the connection between different network copper blocks on the copper base; The second time, the resin is plugged into the groove. The connection position after the second laser cutting is vacuum plugged with resin, then baked, and the resin is correspondingly polished; The second lamination is performed from top to bottom in the manner of the first copper foil, the first PP, the core board, the second PP, and the second copper foil, wherein the second PP is a high thermal conductivity PP.