Preparation method of copper thickness 6OZ flexible plate

Abstract

The invention provides a preparation method of a rigid-flex printed circuit board with a flexible layer copper thickness of 6OZ. The preparation method comprises the following steps: selecting a copper foil with a thickness of 210 [mu] m; performing single-side etching; filling gaps of the single-sided pattern layer with pure glue to form a first filling pattern layer; covering a first covering film; a second surface is etched to form a second single-sided pattern layer, and the second single-sided pattern layer and the first single-sided pattern layer are in mirror image and penetrate through each other; filling gaps of the second single-sided pattern layer with pure glue to form a second filling pattern layer; and covering a second covering film. According to the method, double-face etching, double-face glue filling and double-face film covering are adopted, on one hand, the stability of a product is guaranteed through pure glue filling, on the other hand, the copper layer pattern is prepared through double-face etching till etching penetration, existing etching equipment and technology can be applied, improvement or upgrading and updating are not needed, and meanwhile preparation of the flexible layer copper with the thickness being 6 OZ from copper with the thickness being 6 OZ is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of printed circuit boards, and in particular relates to a processing and manufacturing method for a flexible board with a copper thickness of 6OZ. Background Art

[0002] With the development of electronic information technology, many electronic products that need to carry large currents need to adopt rigid-flexible board design in PCB design. However, the copper thickness of the flexible layer of such products can only be designed to be 3OZ due to insufficient cover film filling. However, in order to meet the current carrying requirements of some flexible electronic products, the copper thickness needs to be designed to be 6OZ.

[0003] Specifically, after the pattern is etched on the copper foil of the flexible layer, a covering film is attached to the surface for protection. The adhesive layer of the covering film is used to fill the gaps in the pattern. However, due to the thickness limitation of the adhesive layer of the covering film, the maximum thickness of the copper foil can only be 3OZ.

[0004] Therefore, it is necessary to provide a method for realizing a rigid-flexible board product with a flexible layer copper thickness of 6OZ. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the object of the present invention is to provide a method for preparing a rigid-flexible board with a copper thickness of 6OZ in the flexible layer.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a rigid-flexible board with a flexible layer copper thickness of 6OZ, comprising the following steps:

[0008] S1, select copper foil with a thickness of 210μm;

[0009] S2, single-sided etching: etching one surface of the copper foil to form a first single-sided layer;

[0010] S3, using pure glue to fill the gaps of the single-sided layer to form a first filling layer;

[0011] S4, covering the surface of the first filling layer with a first covering film;

[0012] S5, second side etching: etching the other surface of the copper foil to form a second single-sided layer, the second single-sided layer and the first single-sided layer are mirror images and penetrate each other;

[0013] S6, filling the gap of the second single-sided layer with pure glue to form a second filling layer;

[0014] S4, covering the surface of the second filling layer with a second covering film.

[0015] Preferably, the sum of the etching depth of the first single-sided layer and the etching depth of the second single-sided layer is not less than, preferably greater than 210 μm.

[0016] Preferably, the etching depths of the first single-sided layer and the second single-sided layer are both 110 μm. Alternatively, the etching depths of the two single-sided layers are different, and the sum of the two etching depths is greater than 210 μm to ensure etching through.

[0017] Preferably, the pure glue filling in S3 and S6 includes: the pure glue in the etching gap forms a filling structure, and there is a gap between the filling structure and the etching gap.

[0018] More preferably, the gap between the filling structure and the etching gap is set such that the length of each single side of the filling structure is 1.5-2.5 mil smaller than the length of each single side of the gap.

[0019] Preferably, the pure rubber described in S3 and S6 is a laminated pure rubber formed by pre-pressing multiple layers of pure rubber.

[0020] More preferably, the multi-layer pure glue is 4 layers.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The manufacturing method of the flexible board with a flexible layer copper thickness of 6OZ implemented by the present invention adopts double-sided etching, double-sided glue filling, and double-sided lamination. On the one hand, the stability of the product is ensured by pure glue filling. On the other hand, the copper layer pattern is prepared by etching the two sides separately until they are etched through. Existing etching equipment and processes can be used without improvement or upgrading. At the same time, the double-sided glue filling is adopted to make the glue filling process easy to control, avoiding insufficient filling or overfilling due to the need for too deep glue filling, resulting in too many gaps, and the effect of glue filling support cannot be achieved, or causing some positions to be overfilled, which easily leads to deformation of the pattern. The present invention can realize a flexible board product with a flexible layer copper thickness of 6OZ through the above technical means, which can better meet the requirements of the industry market. DETAILED DESCRIPTION

[0023] This embodiment provides a method for preparing a rigid-flexible board with a flexible layer copper thickness of 6OZ, and the specific process is as follows:

[0024] 1. Provide raw materials: copper foil with a thickness of 210μm;

[0025] 2. Single-sided etching of copper foil: Cut the copper foil into required size, drill positioning holes and tool holes on the edge of the board, image the inner surface, apply film to both sides of the copper foil, make graphics only on the smooth surface, and expose the rough surface; apply tape to the process holes on the edge of the board, image the inner surface again, and then acid-etch the copper foil, etch away the base copper at a depth of 100-110μm on the smooth surface to form a single-sided graphic circuit, remove the film at normal speed, tear off the tape on the edge of the board before removing the film, and inspect and brown the inner layer;

[0026] 3. Pure glue processing: pure glue cutting to match the size of pure glue with copper foil;

[0027] 4. Take multiple sheets of pure glue, preferably four sheets, overlap and pre-press them together in sequence, and then perform block pressing to form pure glue material. Perform laser milling on the pure glue material to prepare pure glue filling material required for filling, which is used for manual filling. The size of the filling material is designed so that the length of each single side is 2 mil smaller than the corresponding side length of the gap to be filled. In this step, the purpose of using multiple sheets of pure glue for overlapping and pre-pressing is to avoid uneven melting of a single thick glue, resulting in uneven filling, voids or overfilling.

[0028] 5. Use the gap filling material to fill the gap of the single-sided pattern etched in step 2, and then press a covering film on the surface of the copper foil after filling;

[0029] 6. Etch the circuit on the other side: internal light imaging, double-sided filming, expose the surface with the film pasted, that is, the single-sided etching and gap filling film operation has been completed, tape the process holes on the edge of the board, and then internal light imaging again, acid etching the rough surface of the copper foil to form the other side of the pattern circuit. The two sides of the pattern circuit are mirror images, that is, the two sides of the etched pattern circuit are the same circuit, and the copper foil is milled through by etching from both sides. If the etching depth of step 2 is 100μm, the etching depth of step 6 is at least 110μm, and then tear off the board edge tape and browning before de-filming;

[0030] 7. Repeat step 4, or directly use the caulking data in step 4 to manually caulk the gaps of the graphic circuits on the other side obtained in step 6;

[0031] 8. Press the cover film onto the copper foil after the treatment in step 7 to complete the preparation of the flexible layer of the rigid-flexible board;

[0032] 9. Laser makes the graphics required by customers, and then conducts final inspection and packaging.

[0033] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a rigid-flexible board with a flexible layer copper thickness of 6OZ, characterized in that: The following steps are involved: S1, select copper foil with a thickness of 210μm; S2, single-sided etching: etching one surface of the copper foil to form a first single-sided layer; S3, using pure glue to fill the gaps of the single-sided layer to form a first filling layer; S4, covering the surface of the first filling layer with a first covering film; S5, second side etching: etching the other surface of the copper foil to form a second single-sided layer, the second single-sided layer and the first single-sided layer are mirror images and penetrate each other; S6, filling the gap of the second single-sided layer with pure glue to form a second filling layer; S4, covering the surface of the second filling layer with a second covering film.

2. The preparation method according to claim 1, characterized in that: The sum of the etching depth of the first single-sided layer and the etching depth of the second single-sided layer is not less than 210 μm.

3. The preparation method according to claim 2, characterized in that: The etching depths of the first single-sided layer and the second single-sided layer are both 110 μm.

4. The preparation method according to claim 1, characterized in that: The pure glue filling described in S3 and S6 includes: the pure glue in the etching gap forms a filling structure, and there is a gap between the filling structure and the etching gap.

5. The preparation method according to claim 4, characterized in that: The gap between the filling structure and the etching gap is set as follows: the length of each single side of the filling structure is 1.5-2.5 mil smaller than the length of each single side of the gap.

6. The preparation method according to claim 5, characterized in that: The length of each single side of the filling structure is 2 mil shorter than that of each single side of the gap.

7. The preparation method according to any one of claims 1, 4-6, characterized in that: The pure glue described in S3 and S6 is formed by stacking and cutting multiple layers of pure glue.

8. The preparation method according to claim 7, characterized in that: The pure rubber described in S3 and S6 is formed by pre-pressing, block pressing, and laser milling and cutting of multiple layers of pure rubber.

9. The preparation method according to claim 7, characterized in that: The multi-layer pure glue has four layers.