CN115580990A

CN115580990A - Rapid FPC (Flexible printed Circuit) production process by all-dry process

Info

Publication number: CN115580990A
Application number: CN202211318328.9A
Authority: CN
Inventors: 李雪莲
Original assignee: Wuhan Hero Optoelectronics Technology Co ltd
Current assignee: Wuhan Hero Optoelectronics Technology Co ltd
Priority date: 2022-10-26
Filing date: 2022-10-26
Publication date: 2023-01-06

Abstract

The invention discloses a rapid FPC (flexible printed circuit) production process of an all-dry process, which comprises the steps of carrying out circuit manufacturing on an unreeled flexible substrate by laser to generate a circuit board; performing AOI test on the circuit board, and performing film coating operation on the tested circuit board; windowing the circuit board with the covering film attached through laser; carrying out nickel-gold and reinforcing plate pasting operation on the circuit board subjected to windowing treatment; testing the circuit board attached with the reinforcing plate; carrying out laser drilling and shape cutting on the tested circuit board to generate an FPC finished product; and performing FQC test on the FPC finished product and packaging. Through the technical scheme, the invention provides a brand-new FPC manufacturing method, which can realize the full-automatic production of FPC, and completely avoids the waste water discharge and the environmental pollution caused by a chemical method.

Description

Rapid FPC (Flexible printed Circuit) production process by all-dry process

Technical Field

The invention relates to the technical field of FPC (flexible printed circuit) production, in particular to a rapid FPC production process by an all-dry process.

Background

A Flexible Printed Circuit (FPC for short) is a Flexible Printed Circuit board with high reliability and high insulation, which is made of polyimide or polyester film as a base material. The high-density light-weight LED lamp has the characteristics of high wiring density, light weight, thin thickness and good bending property. The common FPC manufacturing process in the prior art is as follows: unreeling, drilling, black hole plating, copper plating, dry film pasting, exposure, development, etching, film stripping, AOI, covering film, nickel gold, silk screen printing solder resistance, reinforcing plate pasting, forming 1, testing, forming 2-FQC-packaging. However, in the above process, for the FPC production, the production process is more and complicated, and cannot meet the requirement of the FPC rapid production, and meanwhile, the etching in the existing process is generally performed by a chemical method, and chemical reagents used in the etching process easily cause certain pollution to the environment, are not favorable for the environmental protection requirement, require huge investment in building wastewater treatment equipment, and have high operation cost.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a rapid FPC production process by an all-dry process, which can save the traditional process procedure and reduce the environmental impact and the investment capital.

In order to achieve the technical purpose, the invention provides the following technical scheme:

a rapid FPC production process of an all-dry process comprises the following steps:

carrying out circuit manufacturing on the unreeled flexible substrate through laser to generate a circuit board; performing AOI test on the circuit board, and performing film coating operation on the tested circuit board; windowing the circuit board with the covering film attached through laser; carrying out nickel-gold and reinforcing plate pasting operation on the circuit board subjected to windowing treatment; testing the circuit board attached with the reinforcing plate; carrying out laser drilling and shape cutting on the tested circuit board to generate an FPC finished product; and performing FQC test on the FPC finished product and packaging.

Optionally, the process of manufacturing the circuit includes: the method comprises the steps of carrying out laser etching on a copper foil layer of a flexible substrate through laser equipment, etching an interval area on the flexible substrate through laser in the etching process, wherein the interval area is used for separating a copper foil of an FPC (flexible printed circuit) circuit and a waste copper foil, and removing the waste copper foil in the interval area through laser to generate the circuit board.

Optionally, the process of the windowing operation includes: the method comprises the steps of obtaining a first image of a circuit board with a covering film attached to the circuit board through a camera, analyzing the first image according to machine vision, obtaining a windowing position, generating a control signal according to the windowing position, and windowing the flexible substrate through laser equipment.

Optionally, the laser drilling and the profile cutting process includes:

and acquiring a second image of the tested circuit board through the camera, acquiring a sample image, matching the second image with the sample image, acquiring windowing and shape cutting positions based on a matching result, mapping the windowing and shape cutting positions to the circuit board, and windowing the windowing and shape cutting positions through laser to generate an FPC (flexible printed circuit) finished product.

Optionally, in the AOI testing process, the circuit board is fixed, and after the circuit board is fixed, the circuit board is scanned by the camera to obtain a third image of the circuit board, and according to the third image, the third image is subjected to defect identification to obtain a defect identification result, and whether the AOI testing is qualified is judged according to the defect identification result.

Optionally, the reinforcing plate of the stiffening plate includes a metal reinforcing plate, a PI reinforcing plate, and a glass fiber reinforcing plate.

Optionally, in the FQC testing process, the appearance image of the FPC finished product is scanned, the appearance image is identified through the deep learning model to generate an appearance detection result, the performance of the FPC finished product is tested according to the appearance detection result, and the FPC finished product is packaged according to the performance detection result.

Optionally, the flexible substrate is a PI substrate covered with a copper foil.

The invention has the following technical effects:

compared with the traditional chemical etching method which only depends on manual production, the invention can realize the full-automatic production of the FPC, and completely has no waste water discharge, thereby avoiding the pollution of the chemical method to the environment.

The invention adopts a new process, not only saves the traditional process procedure, but also greatly reduces the equipment investment of the related process, simultaneously has no environmental protection pressure of chemical etching, also avoids the investment of a punching die for molding and stops huge noise pollution. The manufacture of the entire FPC can be substantially completed by one laser device. The method is particularly suitable for manufacturing single-sided FPC boards, and is particularly suitable for CCS of new energy batteries, automobile antennas, mobile phone antennas and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic process flow diagram provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a circuit fabrication provided by an embodiment of the present invention;

FIG. 3 is a schematic representation of an embodiment of the present invention after forming with scrap removal;

FIG. 4 is a schematic view of a cover film attached according to an embodiment of the present invention;

FIG. 5 is a schematic view of a window according to an embodiment of the present invention;

fig. 6 is a schematic diagram of the cutting and forming according to the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to solve the problems existing in the prior art, the invention provides the following scheme:

as shown in fig. 1, the present invention provides a fast FPC production process by an all-dry process, which comprises the steps of unwinding-laser 1 (circuit making) -AOI-coverlay-laser 2 (windowing) -nickel gold-bonding stiffener-test-laser 3 (drilling, profile cutting) -FQC-packaging. The present invention is specifically explained by the following steps:

unreeling: unreeling the coil stock through FPC unreeling machine, unreeling the glueless substrate of lapping on the flexible substrate promptly, unreeling the in-process and levelly and smoothly unfolding the glueless substrate, carry out later operation on the flexible substrate after unreeling. The non-glue base material used in the invention only consists of the copper foil and the PI material, and the PI material is covered with the copper foil, so that the non-glue base material has the advantages of being thinner, better in dimensional stability, higher in heat resistance, higher in bending resistance, better in chemical resistance and the like compared with a glue base material.

Laser line manufacturing: the method comprises the steps of extracting a line sample image in a computer, aligning the sample image with an area where a line needs to be manufactured after the extraction to generate a line path, and cutting a copper foil layer of a flexible substrate along the edge of the line path by using laser on the basis of the line path, wherein the PI film below the copper foil is not cut through. Removing redundant copper foils outside the circuit after cutting, in the process, calculating and controlling laser equipment to carry out laser etching on the flexible substrate, etching the edge of the circuit as an interval area during etching, wherein the interval area is used for separating an FPC circuit copper foil and a waste copper foil, as shown in figure 2, one part of the FPC circuit copper foil needing to be reserved and one part of the redundant waste copper foil are used, after the interval area is etched on the substrate, setting the area needing to be removed by a computer, the waste copper foil of the area needing to be removed is the copper foil in the interval area and the residual copper foil on the interval area, removing the copper foils except the circuit without etching a PI film below the PI film, wherein the wavelength of the laser is 355nm, the pulse width is 1-12 ps, the output average power is 0-20W, the repetition frequency is 30-800 kHz, the defocusing amount is-3 mm, etching is carried out by the laser, and after etching is finished, as shown in figure 3, the substrate with the circuit, namely the circuit board is generated.

In the AOI optical automatic detection process, a circuit board is fixed, the circuit board is scanned through a camera after the circuit board is fixed, an image of the circuit board, namely a third image, is obtained, and the defect of the circuit board image is identified through a machine vision method.

And (3) attaching a covering film, namely attaching a covering film on the molded copper foil, wherein in the process of attaching the covering film, the covering film is made of a material combining PI and glue, and a circuit board with the covering film is generated as shown in figure 4.

The method comprises the steps that a laser 2 is used for windowing, a covering film on a bonding pad is etched to expose a through hole, in the process, a camera is used for shooting a first image, namely a circuit board image subjected to the previous operation, machine vision is used for analyzing and processing the first image, in the process, a windowing sample image is obtained, the windowing sample image is subjected to feature matching with the shot image, the same circuit features are matched, after matching is completed, a windowing position in the sample image is mapped to the shot image and marked, after marking, a control signal aiming at the relevant position is generated, the control signal controls a laser device to perform windowing processing on the position, and as shown in fig. 5, the windowed circuit board is generated.

Nickel-gold, replacing palladium on the surface of copper by chemical reaction, plating a nickel-phosphorus alloy layer on the basis of palladium core, and plating a gold layer on the surface of nickel by replacement reaction. Surface treatments for circuit boards are used to prevent the copper on the surface of the circuit board from oxidation or corrosion, and for soldering and for contact applications.

Paste the stiffening plate, this in-process, strong board in the stiffening plate includes that metal is strong board, PI are strong board and glass fiber is strong board, pastes the circuit board with strong board on, promotes flexible substrate's intensity.

And testing, namely testing the peel strength of the circuit board attached with the reinforcing plate.

The method comprises the steps of laser 3 drilling, shape cutting and forming, shooting a second image of a tested circuit board by using a camera, obtaining a drilling and shape cutting sample image, setting a cutting area of the circuit board in the image, carrying out feature matching on the sample image and the image of the circuit board, mapping the drilling and cutting area in the sample image to the image of the circuit board after matching is finished, extracting the size of the drilling position and the edge line of the cutting area mapped in the image of the circuit board, generating a related control signal, transmitting the signal to laser equipment, and controlling the laser equipment to cut at the position of the drilling position and the position of the edge line of the cutting area, wherein an FPC finished product is generated as shown in figure 6.

FQC, carry out the FQC test to the FPC finished product, in above-mentioned process, at first carry out outward appearance to the FPC finished product and detect, shoot the finished outward appearance image of FPC through camera scanning, and discern the outward appearance image through the degree of deep learning model, discern through convolutional neural network in this content, including five convolutional layers and two full-connected layers and an output layer, carry out the construction of above-mentioned model through the python subassembly, after the construction is accomplished, gather negative sample and positive sample and train above-mentioned model, the proportion of negative sample and positive sample is 3: and 7, marking the defects in the negative sample and indicating the defect types, identifying the appearance image through the trained model, identifying different defects, performing performance test on the cut circuit board after the defect identification is completed, and packaging after the performance test is completed.

And (5) packaging, namely packaging the circuit board subjected to FQC to generate an FPC product.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A rapid FPC production process of an all-dry process is characterized by comprising the following steps:

carrying out circuit manufacturing on the unreeled flexible substrate through laser to generate a circuit board; performing AOI test on the circuit board, and performing film covering operation on the tested circuit board; windowing the circuit board with the covering film attached through laser; carrying out nickel-gold and reinforcing plate pasting operation on the circuit board subjected to windowing treatment; testing the circuit board attached with the reinforcing plate; carrying out laser drilling and shape cutting on the tested circuit board to generate an FPC finished product; and (5) carrying out FQC test on the FPC finished product and packaging.

2. The rapid FPC production process by the all-dry process according to claim 1, wherein:

the circuit manufacturing process comprises the following steps: carrying out laser etching on the copper foil layer of the flexible substrate through laser equipment, etching an interval area on the flexible substrate through laser in the etching process, wherein the interval area is used for separating a copper foil of an FPC (flexible printed circuit) circuit and a waste copper foil, and removing the waste copper foil in the interval area through laser to generate a circuit board.

3. The rapid FPC production process by the all-dry process according to claim 1, wherein:

the process of the windowing operation comprises: the method comprises the steps of obtaining a first image of a circuit board with a covering film attached to the circuit board through a camera, analyzing the first image according to machine vision, obtaining a windowing position, generating a control signal according to the windowing position, and windowing the flexible substrate through laser equipment.

4. The rapid FPC production process by the all-dry process according to claim 1, wherein:

wherein the process of laser drilling and profile cutting comprises:

5. The rapid FPC production process by all-dry process according to claim 1, wherein:

in the AOI test process, the circuit board is fixed, after the circuit board is fixed, the circuit board is scanned through the camera, a third image of the circuit board is obtained, defect identification is carried out on the third image according to the third image, a defect identification result is obtained, and whether the AOI test is qualified or not is judged according to the defect identification result.

6. The rapid FPC production process by the all-dry process according to claim 1, wherein:

the strong plate in the reinforcing plate comprises a metal strong plate, a PI strong plate and a glass fiber strong plate.

7. The rapid FPC production process by the all-dry process according to claim 1, wherein:

in the FQC testing process, scanning the appearance image of the FPC finished product, identifying the appearance image through a deep learning model to generate an appearance detection result, performing performance testing on the FPC finished product according to the appearance detection result, and packaging the FPC finished product according to the performance detection result.

8. The rapid FPC production process by the all-dry process according to claim 1, wherein:

the flexible substrate is a PI substrate covered with a copper foil.