Copper clad plate manufacturing method

Abstract

The application discloses a copper-clad plate manufacturing method, wherein a prepreg shape is similar to a required substrate shape, and the size of the prepreg is larger than the size of the required substrate; upper and lower mirror surface steel plates are respectively attached to upper and lower sides of a copper-clad plate stack to form a post-pressing product by being sent into a press; the mirror surface steel plates are similar in shape to the prepreg, the size of the mirror surface steel plates is larger than the size of the required substrate, and the size of the mirror surface steel plates is smaller than the size of the prepreg, and the edges of the prepreg uniformly project out of the mirror surface steel plates; the area outside the attachment of the mirror surface steel plates of the post-pressing product is cut according to the size of the required substrate to obtain a copper-clad plate product. The copper-clad plate manufacturing method can prevent uneven glue flow in the hot pressing process from affecting product quality, does not need to additionally increase obstacles, has no influence on the laminating process, is simple, has less influence on cutting positioning, can reduce copper foil waste, saves cost, and reduces pollution.

Description

Technical Field

[0001] This invention relates to copper clad laminate manufacturing technology, and particularly to a method for manufacturing copper clad laminates. Background Technology

[0002] Copper-clad laminate (CCL) is a prepreg (PP) sheet made by impregnating a reinforcing material with resin and baking it at high temperature. One or more prepreg sheets are then sliced ​​and stacked together, with copper foil covering one or both sides, and then hot-pressed to form the final product. It is primarily used in the manufacture of printed circuit boards (PCBs). Multiple PCBs are laminated together using prepreg to form a multilayer circuit board.

[0003] The resin in the prepreg has a low degree of cross-linking and will remelt during hot pressing. In a vacuum laminator, due to the vacuum and press pressure, the resin melts, forming a liquid that expels internal air. Simultaneously, the liquid also flows out from the outer edge of the prepreg. Therefore, the copper foil size needs to be slightly larger than the prepreg size. The resin continues its cross-linking reaction during hot pressing and eventually cures. This phenomenon of the liquid flowing out from the outer edge of the prepreg during the pressing process is called resin flow.

[0004] Excessive resin flow is normal, but it should not be excessive. When excessive resin flow causes voids at the edges of the copper-clad laminate (CCL), it is called insufficient resin flow. Furthermore, excessive resin flow will cause the thickness at the edges of the CCL to be significantly lower than the thickness in the middle, degrading the quality of the CCL. Even more seriously, resin flow onto mirror-finish steel sheets will severely impact production efficiency and product quality.

[0005] Generally, prepregs are rectangular. Due to the characteristics of adhesive flow, less adhesive flows at the four corners than in the middle area of ​​the four sides, so white corners are prone to appear at the four corners.

[0006] Meanwhile, the mirror steel plate is about 1 inch larger than the prepreg in length and width. Since there is no glass cloth to adhere to at the edge of the prepreg and it is also under the pressure of the mirror steel plate, the adhesive is more likely to flow out, and the thickness of the plate at the edge is more likely to be thinner.

[0007] When multiple copper-clad laminates are laminated together at the same time, due to the asynchrony of temperatures, the outer sheets will have more adhesive flow than the inner sheets. Therefore, the outer sheets tend to be thinner than the inner sheets.

[0008] In addition, uneven adhesive flow at the edges can cause positioning deviations during substrate cutting, affecting the cutting quality.

[0009] Existing methods for controlling adhesive flow and improving its uniformity include reducing flow by controlling lamination processes such as heating rate and pressure, or by adding external barriers to the outer edge of the prepreg (PP) to prevent flow. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a method for manufacturing copper-clad laminates that can prevent uneven glue flow during hot pressing from affecting product quality, and does not require additional obstacles, has no impact on the lamination process, is simple, has little impact on cutting and positioning, and can reduce copper foil waste, save costs and reduce pollution.

[0011] To solve the above-mentioned technical problems, the present invention provides a method for manufacturing copper-clad laminates, which includes the following steps:

[0012] S1. A copper foil 2 or release film is attached to the upper and / or lower side of the prepreg 1 to form a copper-clad laminate; the shape of the prepreg is similar to the shape of the required substrate and the size of the prepreg is larger than the size of the required substrate;

[0013] S2. The upper and lower mirror steel plates 3 are respectively attached to the upper and lower sides of the copper clad laminate and fed into a press to form the pressed product; the shape of the mirror steel plate 3 is similar to that of the prepreg 1, the size of the mirror steel plate 3 is larger than the size of the required substrate, and the size of the mirror steel plate 3 is smaller than the size of the prepreg 1, and the edge of the prepreg 1 extends evenly out of the mirror steel plate 3.

[0014] S3. Cut off the area outside the bonding area of ​​the mirror steel plate 3 of the laminated product according to the required substrate size to obtain the finished copper-clad laminate.

[0015] Preferably, the release film is a PET film or a BOPP film.

[0016] Preferably, the substrate is required to be 43 inches × 49 inches;

[0017] The prepreg measures 44 inches × 50 inches.

[0018] The mirror-finished steel plate measures 43.5 inches by 49.5 inches.

[0019] Preferably, the thickness of the prepreg 1 is 0.1 mm to 3 mm.

[0020] Preferably, the prepreg 1, the mirror steel plate 3, and the copper foil 2 are all rectangular.

[0021] Preferably, in step S2, the upper and lower mirror steel plates 3 are respectively attached to the upper and lower sides of the copper-clad laminate, and then fed into a press to be pressed and cured at a temperature of 50℃~300℃ to form the pressed product.

[0022] Preferably, the size of the copper foil 2 is 0.9 to 1.02 times the size of the prepreg 1.

[0023] Preferably, the size of the mirror steel plate 3 is 1.0001 to 1.05 times the size of the required substrate.

[0024] The copper-clad laminate manufacturing method of the present invention involves designing the size of the mirror steel plate 3 between the required substrate size and the size of the prepreg 1. After lamination, the area outside the bonding area of ​​the mirror steel plate 3 (not subjected to pressure from the mirror steel plate) of the laminated product is cut off according to the required substrate size to obtain the finished copper-clad laminate. In this copper-clad laminate manufacturing method, during lamination, the adhesive flow outside the size of the mirror steel plate 3 is no longer subjected to pressure. Simultaneously, the prepreg 1 outside the mirror steel plate 3 also hinders adhesive flow to a certain extent, preventing uneven adhesive flow during hot pressing from affecting product quality. Furthermore, no additional obstacles are needed, and the lamination process is unaffected, making the method simple. During cutting, since the adhesive flow is concentrated in the area of ​​the prepreg 1 extending beyond the mirror steel plate 3, the impact on cutting positioning is minimal. Moreover, due to the reduced adhesive flow distance, the size of the copper foil 2 can be correspondingly reduced, minimizing copper foil waste, saving costs, and reducing pollution. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly introduced below. Obviously, the 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.

[0026] Figure 1 This is a flowchart of an embodiment of the copper-clad laminate manufacturing method of the present invention;

[0027] Figure 2 This is a top view of an embodiment of the copper clad laminate manufacturing method of the present invention, in which upper and lower mirror steel plates are respectively attached to the upper and lower sides of the copper clad laminate stack.

[0028] Figure 3 This is a side view of an embodiment of the copper clad laminate manufacturing method of the present invention, in which upper and lower mirror steel plates are respectively attached to the upper and lower sides of the copper clad laminate stack.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Prepreg; 2. Copper foil; 3. Mirror steel plate. Detailed Implementation

[0031] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] like Figure 1 As shown, the copper clad laminate manufacturing method includes the following steps:

[0034] S1. A copper foil 2 or release film is attached to the upper and / or lower side of the prepreg 1 to form a copper-clad laminate; the shape of the prepreg is similar to the shape of the required substrate and the size of the prepreg is larger than the size of the required substrate;

[0035] S2. For example Figure 2 , Figure 3 As shown, the upper and lower mirror steel plates 3 are respectively attached to the upper and lower sides of the copper clad laminate and fed into a press to form the pressed product; the shape of the mirror steel plate 3 is similar to that of the prepreg 1, the size of the mirror steel plate 3 is larger than the size of the required substrate, and the size of the mirror steel plate 3 is smaller than the size of the prepreg 1, and the edge of the prepreg 1 extends uniformly out of the mirror steel plate 3.

[0036] S3. Cut off the area outside the bonding area of ​​the mirror steel plate 3 of the laminated product according to the required substrate size to obtain the finished copper-clad laminate.

[0037] Preferably, the release film is a thin release film such as PET film or BOPP film.

[0038] The copper-clad laminate manufacturing method of Example 1 involves designing the size of the mirror steel plate 3 between the required substrate size and the size of the prepreg 1. After lamination, the area outside the bonding area of ​​the mirror steel plate 3 (not subjected to pressure from the mirror steel plate) of the laminated product is cut off according to the required substrate size, resulting in the finished copper-clad laminate. In this method, during lamination, the adhesive flow outside the dimensions of the mirror steel plate 3 is no longer subjected to pressure. Simultaneously, the prepreg 1 outside the mirror steel plate 3 also hinders adhesive flow to some extent, preventing uneven adhesive flow during hot pressing from affecting product quality. Furthermore, no additional obstacles are needed, and the lamination process is unaffected, making the method simple. During cutting, since the adhesive flow is concentrated in the area of ​​the prepreg 1 extending beyond the mirror steel plate 3, the impact on cutting positioning is minimal. Moreover, due to the reduced adhesive flow distance, the size of the copper foil 2 can be correspondingly reduced, minimizing copper foil waste, saving costs, and reducing pollution.

[0039] Example 2

[0040] Based on the copper clad laminate manufacturing method of Embodiment 1, the required size of the substrate is 43 inches × 49 inches;

[0041] The prepreg measures 44 inches × 50 inches.

[0042] The mirror-finished steel plate measures 43.5 inches by 49.5 inches.

[0043] Preferably, the thickness of the prepreg 1 is 0.1 mm to 3 mm.

[0044] Example 3

[0045] Based on the copper clad laminate manufacturing method of Example 1, the prepreg 1, the mirror steel plate 3, and the copper foil 2 are all rectangular.

[0046] Preferably, in step S2, the upper and lower mirror steel plates 3 are respectively attached to the upper and lower sides of the copper-clad laminate, and then fed into a press to be pressed and cured at a temperature of 50℃~300℃ to form the pressed product.

[0047] Example 4

[0048] Based on the copper clad laminate manufacturing method of Example 1, the size of the copper foil 2 is 0.9 to 1.02 times the size of the prepreg 1.

[0049] The size of copper foil 2 can be determined according to the glue flow situation: when there is a lot of glue flow, the size of copper foil 2 should be slightly larger than the size of prepreg 1; when there is a little glue flow, the size of copper foil 2 can be slightly smaller than the size of prepreg 1.

[0050] Example 5

[0051] Based on the copper clad laminate manufacturing method of Example 1, the size of the mirror steel plate 3 is 1.0001 to 1.05 times the required substrate size.

[0052] To ensure the size of the substrate after cutting, there are certain requirements for the positioning accuracy of the mirror steel plate 3 during the production process. The smaller the difference between the size of the mirror steel plate 3 and the required substrate size, the higher the positioning accuracy requirement of the mirror steel plate 3.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing copper-clad laminate, characterized in that, Includes the following steps: S1. A copper foil (2) or release film is attached to the upper and / or lower side of the prepreg (1) to form a copper-clad laminate; the shape of the prepreg is similar to the shape of the required substrate and the size of the prepreg is larger than the size of the required substrate; S2. The upper and lower mirror steel plates (3) are respectively attached to the upper and lower sides of the copper clad laminate and sent into the press to form the pressed product; the shape of the mirror steel plate (3) is similar to that of the prepreg (1), the size of the mirror steel plate (3) is larger than the size of the required substrate, and the size of the mirror steel plate (3) is smaller than the size of the prepreg (1), and the edge of the prepreg (1) extends evenly out of the mirror steel plate (3); S3. Cut off the area outside the bonding area of ​​the mirror steel plate (3) of the laminated product according to the required substrate size to obtain the finished copper-clad laminate.

2. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, The release film is a PET film or a BOPP film.

3. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, The required dimensions of the substrate are 43 inches × 49 inches; The prepreg measures 44 inches × 50 inches. The mirror-finished steel plate measures 43.5 inches by 49.5 inches.

4. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, The thickness of the semi-cured sheet (1) is 0.1 mm to 3 mm.

5. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, The prepreg (1), mirror steel plate (3) and copper foil (2) are all rectangular.

6. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, In step S2, the upper and lower mirror steel plates (3) are respectively attached to the upper and lower sides of the copper-clad laminate and sent into the press to be pressed and cured at a temperature of 50℃~300℃ to form the pressed product.

7. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, The size of the copper foil (2) is 0.9 to 1.02 times the size of the prepreg (1).

8. The method for manufacturing copper-clad laminate according to claim 1, characterized in that, The size of the mirror steel plate (3) is 1.0001 to 1.05 times the size of the required substrate.

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