CN116056371A

CN116056371A - Method for etching and uncovering multilayer board

Info

Publication number: CN116056371A
Application number: CN202310070068.6A
Authority: CN
Inventors: 黄助亮; 张道兵
Original assignee: Shenzhen City Three Golds Precise Circuit Technology Co ltd
Current assignee: Shenzhen City Three Golds Precise Circuit Technology Co ltd
Priority date: 2023-02-07
Filing date: 2023-02-07
Publication date: 2023-05-02

Abstract

The embodiment of the invention provides a method for etching and uncovering a multilayer board, which comprises the following steps: manufacturing a first FPC flexible board, and enabling the golden finger position on the first FPC flexible board to be in a naked state; manufacturing a second FPC flexible board, and etching mark lines corresponding to the golden finger edge profile on the second FPC flexible board; aligning and attaching a second FPC flexible board to the first FPC flexible board; and tearing off the corresponding area on the second FPC flexible board along the marking line to finish uncapping. Compared with the prior art, the embodiment of the invention provides a multilayer board etching uncapping method, which is characterized in that the marking lines are etched on the flexible board needing the uncapping layer in advance, and the corresponding areas are removed along the marking lines after the multilayer flexible board is aligned and attached, so that a simple and efficient uncapping process is realized, the uncapping mode can not damage the circuit board lines, and the product quality and the processing efficiency are improved.

Description

Method for etching and uncovering multilayer board

Technical Field

The invention relates to the technical field of flexible circuit board processing, in particular to a flexible multilayer board etching uncovering method.

Background

With the development of technology, electronic products have been gradually developed toward high density, miniaturization and high reliability, and Printed Circuit Boards (PCB) supporting the electronic products have been gradually developed toward light, thin and flexible. Among them, flexible Printed Circuit (FPC) has been increasingly used in electronic products with its advantages of being bendable, foldable, three-dimensional wiring, three-dimensional space interconnection, and the like, and has replaced conventional rigid printed circuit boards in many places. Particularly, an ultra-thin flexible printed wiring board is widely used in electronic products due to its superior flexibility. The flexible circuit board comprises a single-layer flexible circuit board, a multi-layer flexible circuit board with a single-layer structure locally, and the like, and for mobile phones, tablet computers and the like, the multi-layer flexible circuit board with the single-layer structure locally is generally adopted due to the self-structure requirement.

Along with the development of electronic products on the light, thin, short and high-density multifunctional three-dimensional assembly and interconnection of circuit boards, the multilayer flexible circuit board is more and more in demand, and as the products need three-dimensional bending and assembly, the multilayer material superposition is thicker and harder and is inconvenient to bend, the uncovering process is provided, and the uncovering is aimed at the design that the multilayer board needs to expose the golden finger of the inner layer, so that the products are locally thinned and are convenient to bend. In the prior art, the laser uncapping is generally adopted for uncapping, and because the multilayer board is formed by pressing a multilayer circuit board, the thickness of a product after lamination has fluctuation, and in the manufacturing process, the thickness of materials and copper plating also has tolerance, so that the thickness of an uncapping area of the product is uneven, the energy control difficulty of laser is very high when the laser uncapping is adopted, and the laser energy is low, so that the laser is not thoroughly cut and uncapping is not realized; and when the laser energy is high, the laser is easy to cut into the bottom circuit, so that the problems of poor functions such as open circuit and the like are caused.

Disclosure of Invention

The embodiment of the invention provides a multilayer board etching uncapping method, which aims to solve the technical problems that the existing laser opening mode is difficult to control laser energy, so that the product is defective or uncapping is impossible.

In order to achieve the above purpose, the technical scheme provided by the invention is as follows:

the invention provides a method for etching and uncovering a multilayer plate, which comprises the following steps:

manufacturing a first FPC flexible board, and enabling the golden finger position on the first FPC flexible board to be in a naked state;

manufacturing a second FPC flexible board, and etching mark lines corresponding to the golden finger edge profile on the second FPC flexible board;

aligning and attaching a second FPC flexible board to the first FPC flexible board;

and tearing off the corresponding area on the second FPC flexible board along the marking line to finish uncapping.

The method for manufacturing the first FPC flexible board comprises the following steps of:

etching a circuit on one surface of the first FPC flexible board to form a circuit board with golden fingers;

and (3) punching out a window at the golden finger position by adopting a die, so that photoresist removal of the golden finger area is in an exposed state.

The manufacturing method of the second FPC flexible board comprises the following steps of: dry film, exposure, development, demoulding and etching; and the etching step comprises the step of etching a marking line on the second FPC flexible board at a position corresponding to the golden finger of the first FPC flexible board.

Wherein the width of the marking line is not less than 0.2mm.

And tearing off the corresponding area on the second FPC flexible board along the marking line to finish uncovering, wherein the film tearing action is carried out by picking up one corner of the corresponding area on the second FPC flexible board.

And tearing off the corresponding area on the second FPC flexible board along the marking line to finish uncovering, wherein a pen knife is adopted to pick up one corner of the corresponding area on the second FPC flexible board.

And in the step of aligning and attaching the second FPC flexible board to the first FPC flexible board, the PI surface of the first FPC flexible board is aligned and attached with one surface of the exposed golden finger of the second FPC flexible board through pure glue.

Compared with the prior art, the embodiment of the invention provides a multilayer board etching uncapping method, which is characterized in that the marking lines are etched on the flexible board needing the uncapping layer in advance, and the corresponding areas are removed along the marking lines after the multilayer flexible board is aligned and attached, so that a simple and efficient uncapping process is realized, the uncapping mode can not damage the circuit board lines, and the product quality and the processing efficiency are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a main flow chart of a method for etching and uncovering a multilayer board according to an embodiment of the present invention;

fig. 2 is a sub-flowchart of a method for etching and uncovering a multi-layer board according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

Referring to fig. 1, fig. 1 is a flowchart of a method for etching and uncovering a multi-layer board according to an embodiment of the present invention, in which a three-layer flexible circuit board is taken as an example for explanation, the method for etching and uncovering a multi-layer board includes the following steps:

s100, manufacturing a first FPC flexible board, and enabling the golden finger position on the first FPC flexible board to be in a naked state;

the step S100 of manufacturing a first FPC flexible board and exposing the golden finger on the first FPC flexible board includes the following steps:

step S101, etching a circuit on one surface of a first FPC flexible board to form a circuit board with golden fingers;

step S102, a mold is adopted to punch out a window at the golden finger position, so that photoresist removal of the golden finger area is in an exposed state.

The first FPC flexible board is a double-layer board, and first, one surface of the double-layer board is subjected to circuit etching to form a golden finger flexible circuit board with golden fingers, and the surface of the golden finger flexible circuit board with the golden fingers is coated with pure glue, and the pure glue covers the golden fingers, so that a window needs to be punched through a die, and the golden fingers are exposed.

Step S200, manufacturing a second FPC flexible board, and etching mark lines corresponding to the edge profile of the golden finger on the second FPC flexible board;

the step S200 of manufacturing a second FPC flexible board, etching a mark line corresponding to the golden finger edge profile on the second FPC flexible board includes the following steps: dry film, exposure, development, demoulding and etching; the second FPC flexible board is a single-sided board, and the etching step comprises the step of etching marking lines on the second FPC flexible board at positions corresponding to golden fingers of the first FPC flexible board. The steps of dry film, exposure, development and demolding are all conventional processing steps of the conventional flexible circuit board, and are different from the conventional processing steps in that in the etching step, not only a circuit is needed to be etched, but also a region corresponding to a golden finger on the first FPC flexible board is needed to be etched with a rib profile, namely a mark line, and the rib profile corresponds to the shape of the golden finger and can be a straight line.

Step S300, aligning and attaching a second FPC flexible board to the first FPC flexible board; because the golden finger position on the first FPC flexible board is windowed and the pure glue is removed, after the second FPC flexible board is aligned and pasted with the first FPC flexible board, the area surrounded by the marking lines and the golden finger area cannot be bonded together, so that the subsequent uncovering treatment is facilitated.

And S400, tearing off the corresponding area on the second FPC flexible board along the marking line to finish uncapping.

Wherein the width of the marking line is not less than 0.2mm.

Specifically, in the step S400, the corresponding area on the second FPC flexible board is torn off along the marking line to complete the uncovering, and the film tearing action is performed by picking up from one corner of the corresponding area on the second FPC flexible board.

And step S400, tearing off the corresponding area on the second FPC flexible board along the marking line to finish uncovering, wherein a pen knife is used for lifting one corner of the corresponding area on the second FPC flexible board.

And the step S300 is to attach the second FPC flexible board to the first FPC flexible board in an alignment manner, namely attach the PI surface of the first FPC flexible board to one surface of the exposed golden finger of the second FPC flexible board in an alignment manner through pure glue.

Compared with the prior art, the multilayer board etching uncapping method of the embodiment etches the marking line on the flexible board needing the uncapping layer in advance, and removes the corresponding area along the marking line after the multilayer flexible board is aligned and attached, so that a simple and efficient uncapping process is realized, the uncapping mode can not damage the circuit board line, and the product quality and the processing efficiency are improved.

The foregoing is merely illustrative of the preferred embodiments of the present invention and is not intended to limit the embodiments of the present invention, and those skilled in the art can easily make corresponding variations or modifications according to the main concept and spirit of the present invention, so the protection scope of the present invention shall be defined by the claims.

Claims

1. The method for etching and uncovering the multilayer plate is characterized by comprising the following steps of:

2. The method for etching and uncovering a multilayer board according to claim 1, wherein said step of manufacturing a first FPC flexible board and making a gold finger position on said first FPC flexible board in a bare state comprises the steps of:

3. The method for etching and uncovering a multilayer board according to claim 2, wherein said step of manufacturing a second FPC flexible board, etching a mark line corresponding to said golden finger profile on the second FPC flexible board, comprises the steps of: dry film, exposure, development, demoulding and etching; and the etching step comprises the step of etching a marking line on the second FPC flexible board at a position corresponding to the golden finger of the first FPC flexible board.

4. A multi-layer board etching uncapping method as in claim 3 wherein the width of the marking line is not less than 0.2mm.

5. The method of etching a cover on a multi-layer board according to claim 4, wherein the step of tearing the corresponding region of the second FPC flexible board along the mark line to complete the cover opening is performed by picking up the film from one of corners of the corresponding region of the second FPC flexible board.

6. The method of etching a cover on a multi-layer board according to claim 5, wherein the step of tearing off the corresponding area on the second FPC flexible board along the mark line to complete the cover opening is to pick up one of corners of the corresponding area on the second FPC flexible board with a pen knife.

7. The method for etching and uncovering a multilayer board according to claim 5, wherein in the step of aligning and attaching the second FPC flexible board to the first FPC flexible board, the PI surface of the first FPC flexible board is aligned and attached to one surface of the bare gold finger of the second FPC flexible board through a pure glue.