A method for processing a roll of FPC

Abstract

This invention relates to a method for processing FPC rolls, comprising stacking and bonding raw materials to form a die-cut strip consisting of a first protective film, a first release film, double-sided adhesive, PI tape, and a second release film stacked sequentially from bottom to top; a first punching cut to remove edge waste and form multiple arrayed circular holes; then, an FPC sheet is laminated onto the strip, followed by a second punching cut to remove waste material other than the circuit board material from the FPC sheet, resulting in the FPC product. Compared with existing technologies, this invention enables the die-cutting production of flexible circuit boards and has advantages such as simple structure, convenient operation, and high production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of die-cutting technology and relates to a method for processing FPC rolls. Background Technology

[0002] Flexible printed circuit boards (FPCs) are printed circuit boards made of flexible insulating substrates (mainly polyimide or polyester film). They possess many advantages that rigid printed circuit boards lack. For example, they can be freely bent, rolled, and folded. FPCs can significantly reduce the size of electronic products, meeting the needs of electronic products moving towards higher density, miniaturization, and higher reliability. Therefore, FPCs are widely used in aerospace, military, mobile communications, laptops, computer peripherals, PDAs, digital cameras, and other fields and products.

[0003] FPCs also have advantages such as good heat dissipation and solderability, ease of assembly, and low overall cost.

[0004] Flexible printed circuit boards (PCBs) are available in single-sided, double-sided, and multilayer configurations. The primary substrate used is polyimide copper-clad laminate. This material boasts high heat resistance and good dimensional stability. It is pressed together with a cover film that provides both mechanical protection and excellent electrical insulation to form the final product. In double-sided and multilayer PCBs, the surface and inner conductors are metallized to achieve electrical connections between the inner and outer circuit layers.

[0005] Flexible printed circuit boards (FPCBs) can be categorized into four functions: lead line, printed circuit, connector, and integration of function. Their applications cover a wide range of fields, including computers, computer peripherals, consumer electronics, and automobiles.

[0006] Flexible printed circuit boards (FPCBs) can be categorized into four types: single-sided, double-sided, substrate-generated single-sided, and substrate-generated double-sided. Single-sided boards use a single-sided PI copper-clad laminate material, which, after the circuitry is completed, is covered with a protective film to form a flexible circuit board with only a single layer of conductors. Double-sided boards use double-sided PI copper-clad laminate material, with a protective film added to each side after the circuitry is completed, resulting in a circuit board with two layers of conductors. Substrate-generated single-sided boards use pure copper foil material, with a protective film added to each side during the circuitry process, resulting in a circuit board with only a single layer of conductors but exposed conductors on both sides. Substrate-generated double-sided boards use two layers of single-sided PI copper-clad laminate material bonded together with adhesive that has windows at specific locations, creating a double-sided conductor circuit board with a partially bonded and partially separated structure, achieving high flexibility in the delamination areas.

[0007] Flexible printed circuit boards (FPCs) are generally considered to have the following advantages: (1) They can be freely bent, rolled, and folded, and can be arranged arbitrarily according to spatial layout requirements, and can move and stretch arbitrarily in three-dimensional space, thereby achieving the integration of component assembly and wire connection; (2) The size and weight of electronic products can be greatly reduced by using FPCs; (3) FPCs also have the advantages of good heat dissipation and solderability, as well as easy assembly and low overall cost. The design of combining soft and hard materials also makes up for the slight deficiency of flexible substrates in component load-bearing capacity to a certain extent. However, they also have the following disadvantages: (1) High initial cost: Since flexible PCBs are designed and manufactured for special applications, the initial circuit design, wiring and photolithography costs are high. Unless there is a special need to use flexible PCBs, it is usually best not to use them for small applications; (2) It is difficult to modify and repair flexible PCBs: Once a flexible PCB is made, any changes must start from the base drawing or the developed photoplotting program, so it is not easy to modify. Its surface is covered with a protective film, which must be removed before repair and restored after repair, which is a difficult task; (3) Size is limited: Flexible PCBs are usually manufactured using intermittent processes when they are not yet widely used, so they are limited by the size of the production equipment and cannot be made very long or wide; (4) Improper operation can easily damage: Improper operation by assembly personnel can easily cause damage to the flexible circuits, and its soldering and rework require trained personnel to operate. Summary of the Invention

[0008] The purpose of this invention is to provide a method for processing FPC rolls to address at least one of the above-mentioned defects.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] A method for processing FPC rolls includes the following steps:

[0011] S1: Fit

[0012] Stack and bond raw materials to form a die-cut material tape consisting of a first protective film, a first release film, double-sided adhesive, PI tape, and a second release film, layered from bottom to top;

[0013] S2: Single punching

[0014] Continuous outer cutting lines are punched out on the first release film, double-sided adhesive, PI tape, and second release film near the two side edges.

[0015] A pair of continuous inner cutting lines are punched out on the double-sided tape, PI tape, and second release film, between the outer cutting lines;

[0016] An array of circular cut lines are punched out on the first release film, double-sided adhesive, PI tape, and second release film, between the outer and inner cut lines.

[0017] A single punched strip is obtained;

[0018] S3: Primary waste discharge

[0019] The area between the outer edge of the die-cut strip and the adjacent outer cutter line is the outer waste area of ​​the first punching, and the area inside the circular cutter line is the circular hole waste area.

[0020] The double-sided tape, PI tape, and waste material located in the outer waste area on the second release film are peeled off from the top surface of the first die-cut strip; then the first protective film is peeled off from the bottom surface of the first die-cut strip, and the waste material located in the round hole waste area on the first release film is adhered and discharged; then the second protective film is attached to the bottom of the first release film to obtain the first die-cut strip.

[0021] S4: Sheet Assembly

[0022] FPC sheets are attached one by one along the length of the PI tape of the die-cutting strip, with the edges of adjacent FPC sheets being attached together; the FPC sheet includes a sheet body and a circuit board laid on the sheet body.

[0023] S5: Secondary punching

[0024] On the first release film, double-sided adhesive tape, PI tape, FPC sheet, and the first die-cutting strip near the outer edge, continuous sheet edge cut lines are generated;

[0025] An array of contour lines are punched out along the outer contour of the circuit board on double-sided tape, PI tape, and FPC sheet.

[0026] A secondary punched strip is obtained;

[0027] S6: Secondary waste discharge

[0028] The area between the edge of the secondary punching strip and the edge cut line of the adjacent sheet is designated as the outer scrap area of ​​the secondary punching; the area between the contour cut line and the edge cut line of the sheet is designated as the outer frame scrap area.

[0029] Peel off the double-sided adhesive tape, PI tape, and waste material from the outer frame waste area of ​​the FPC sheet from the top surface of the secondary punching strip; then peel off the second protective film and discharge the first release film, double-sided adhesive tape, PI tape, and waste material from the outer waste area of ​​the FPC sheet located on the second punching side.

[0030] This invention first stacks and laminates raw materials to form a die-cut strip consisting of a first protective film, a first release film, double-sided adhesive, PI tape, and a second release film stacked sequentially from bottom to top; then, it undergoes a punching process to remove edge waste and form multiple arrayed circular holes; subsequently, an FPC sheet is laminated onto the strip, and a second punching process is performed to remove waste material other than the circuit board on the FPC sheet, resulting in an FPC product.

[0031] Further, step S1 includes: rolling and bonding a double-sided adhesive tape onto the first release film, peeling off and removing the surface waste of the double-sided adhesive tape to obtain double-sided adhesive; then bonding a PI tape onto the double-sided adhesive by synchronous rolling, and bonding a first protective film onto the bottom surface of the first release film; then bonding a second release film onto the PI tape to form a die-cutting tape.

[0032] Furthermore, the double-sided adhesive tape is made of 3M 467 type double-sided adhesive.

[0033] Furthermore, the PI tape is either 3M 5419 type PI tape or 3M 5433 type PI tape.

[0034] Furthermore, the PI tape used is 3M 5433 type PI tape.

[0035] Further, in step S2, the die-cutting blades used include paired inner cutters, arrayed circular cutters, and outer cutters. The inner cutters, arrayed circular cutters, and outer cutters are arranged sequentially from the middle to both sides along the width direction of the die-cutting strip and are symmetrically arranged about the center line of the strip. The arrayed circular cutters include an array of circular cutters.

[0036] Furthermore, the array of circular cutters includes circular cutters arranged in an inner and outer double-row array.

[0037] Furthermore, in step S4, the circuit board is provided in multiple forms and is arranged at intervals along the length direction on the center line of the sheet body.

[0038] Furthermore, in step S5, the die-cutting blade used includes multiple contour cutters adapted to the contour of the circuit board, and sheet edge cutters disposed on both sides of the multiple contour cutters.

[0039] Further, after step S6, the product undergoes rolling to obtain the FPC product.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] This invention enables the die-cutting production of flexible circuit boards, and has the advantages of simple structure, convenient operation, and high production efficiency. Attached Figure Description

[0042] Figure 1 This is a process flow diagram of the bonding step in an FPC roll processing method according to an embodiment;

[0043] Figure 2 This is a schematic diagram of the structure of a die-cutting tool used in a single punching step of an FPC roll processing method according to an embodiment;

[0044] Figure 3 This is a schematic diagram of a punching step in a coil processing method for FPC, as described in an embodiment.

[0045] Figure 4 This is a process flow diagram of a primary waste removal step in an FPC roll processing method according to an embodiment.

[0046] Figure 5 The diagram shows the structure of FPC sheets; the top diagram shows a single sheet structure; the bottom diagram shows a multi-sheet arrangement.

[0047] Figure 6 This is a schematic diagram of the structure of the die-cutting tool used in the secondary punching step of an FPC roll processing method according to an embodiment;

[0048] Figure 7 This is a schematic diagram of the punching step in a coil processing method for FPC, as described in an embodiment.

[0049] Figure 8 This is a process flow diagram of the secondary waste removal step in an FPC roll processing method according to an embodiment;

[0050] Explanation of markings in the diagram:

[0051] 1-First protective film, 2-First release film, 3-Double-sided adhesive, 4-PI tape, 5-Second release film, 6-Inner side cutter, 7-Arrayed circular cutter, 8-Outer side cutter, 9-Contour cutter, 10-Second protective film, 11-FPC sheet, 1101-Sheet body, 1102-Circuit board, 12-Sheet edge cutter. Detailed Implementation

[0052] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are based on the above-described technical solutions of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0053] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0054] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0055] Example:

[0056] A method for processing FPC rolls includes the following steps:

[0057] S1: Fit

[0058] like Figure 1 As shown, a double-sided adhesive tape is rolled and bonded onto the first release film 2. After peeling off the surface waste of the double-sided adhesive tape, a double-sided adhesive tape 3 is obtained. Then, a PI tape 4 is bonded onto the double-sided adhesive tape 3 by synchronous rolling. A first protective film 1 is bonded to the bottom surface of the first release film 2. Then, a second release film 5 is bonded onto the PI tape 4 to form a die-cut material tape. The double-sided adhesive used is 3M 467 type double-sided adhesive from 3M China Co., Ltd. The PI tape used is 3M 5419 type PI tape from 3M China Co., Ltd. In other embodiments, 3M 5433 type PI tape can be used.

[0059] S2: Single punching

[0060] The die-cutting blade used is such as Figure 2 As shown, it includes a pair of inner cutters 6, an array of circular cutters 7, and an outer cutter 8. The inner cutters 6, the array of circular cutters 7, and the outer cutters 8 are arranged sequentially from the middle to both sides along the width direction of the die-cutting strip and are symmetrically arranged about the center line of the strip. The array of circular cutters 7 includes circular cutters arranged in two rows, one inside and one outside.

[0061] like Figure 3 As shown, the outer cutter 8 punches from the second release film 5 to the first protective film 1. The first protective film 1 is unaffected. The outer cutter lines generated near the outer edge of the die-cutting strip are connected in sequence and form a one-time punching outer waste area between the edge of the die-cutting strip.

[0062] The array of circular hole cutters 7 punches from the second release film 5 to the first protective film 1. The first protective film 1 is unaffected. Two rows of circular cut lines are punched out on the die-cutting strip, and a circular hole waste area is formed inside the circular cut lines.

[0063] The inner cutter 6 punches from the second release film 5 to the first release film 2. The first release film 2 is unaffected. Continuous inner cut lines are punched in the middle of the die-cutting strip, and a middle area of ​​the strip is formed between the two inner cut lines. An outer area of ​​the strip is formed between the inner cut lines and the adjacent outer cut lines.

[0064] A single punched strip is obtained;

[0065] S3: Primary waste discharge

[0066] like Figure 4 As shown, waste materials located in the outer waste area on the first release film 2, double-sided adhesive 3, PI tape 4, and second release film 5 are peeled off from the top surface of the die-cut strip. Then, the first protective film 1 is peeled off from the bottom surface of the die-cut strip, and waste materials located in the round hole waste area on the first release film 2 are adhered and discharged. Waste materials located in the round hole waste area on the double-sided adhesive 3, PI tape 4, and second release film 5 are not discharged. Then, waste materials in the inner waste area are peeled off from the top surface, and the second protective film 10 is attached to the bottom of the first release film 2 to obtain the die-cut strip.

[0067] S4: Sheet Assembly

[0068] FPC sheets 11 are sequentially bonded along their length to the PI tape 4 of the die-cut material strip, with the edges of adjacent FPC sheets 11 bonded together; as follows: Figure 5 As shown, the FPC sheet 11 includes a square sheet body 1101 and a plurality of circuit boards 1102 arranged at intervals along the length direction on the center line of the sheet body 1101.

[0069] S5: Secondary punching

[0070] The die-cutting blade used is such as Figure 6 As shown, it includes multiple contour cutters 9 adapted to the contour of the circuit board 1102, and sheet edge cutters 12 disposed on both sides of the multiple contour cutters 9.

[0071] like Figure 7 As shown, the sheet edge cutter 12 punches from the sheet body 1101 to the second protective film 10, and the second protective film 10 is not punched through; the sheet edge cutter lines generated near the outer edge of the die-cutting strip are connected in sequence, and a secondary punching outer waste area is formed between the die-cutting strip edge and the edge of the die-cutting strip.

[0072] The contour cutter 9 cuts along the outer contour of the circuit board 1102 from the FPC sheet 11 to the first release film 2 without breaking the first release film 2; a contour cut line is formed on the die-cutting strip, and an outer frame waste area is formed between the sheet edge cut line and the contour cut line;

[0073] A secondary punched strip is obtained;

[0074] S6: Secondary waste discharge

[0075] like Figure 8 As shown, the double-sided adhesive tape 3, PI tape 4, and waste material on the FPC sheet 11 located in the outer frame waste area are peeled off from the top surface of the secondary punching strip; then the second protective film 10 is peeled off and the waste material on the first release film 2, double-sided adhesive tape 3, PI tape 4, and FPC sheet 11 located in the outer waste area of ​​the secondary punching is discharged.

[0076] After rolling, an FPC product is obtained on the first release film 2, consisting of double-sided adhesive 3, PI tape 4, and FPC sheet 11 stacked sequentially from bottom to top.

[0077] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method of processing a roll of FPC, characterized by, Includes the following steps: S1: Fit Stacked and bonded materials form a die-cut strip consisting of a first protective film (1), a first release film (2), double-sided adhesive (3), PI tape (4), and a second release film (5) stacked from bottom to top. S2: Single punching On the first release film (2), double-sided adhesive (3), PI tape (4), and second release film (5), near the two side edges, continuous outer cutting lines are punched out respectively; A pair of continuous inner cutting lines are punched out on the double-sided tape (3), PI tape (4), and second release film (5) between the outer cutting lines; On the first release film (2), double-sided adhesive (3), PI tape (4), and second release film (5), between the outer and inner cutting lines, an array of circular cutting lines are punched out respectively. A single punched strip is obtained; S3: One-time waste discharge The area between the outer edge of the die-cut strip and the adjacent outer cutter line is the outer waste area of ​​the first punching, and the area inside the circular cutter line is the circular hole waste area. The waste material located in the outer waste area of ​​the double-sided tape (3), PI tape (4), and second release film (5) on the top surface of the die-cut strip is peeled off; then the first protective film (1) is peeled off from the bottom surface of the die-cut strip, and the waste material located in the round hole waste area on the first release film (2) is adhered and discharged; then the second protective film (10) is attached to the bottom of the first release film (2) to obtain the die-cut strip. S4: Sheet Assembly FPC sheets (11) are attached one by one along the length direction to the PI tape (4) of the die-cut material strip, and the edges of adjacent FPC sheets (11) are attached together; the FPC sheet (11) includes a sheet body (1101) and a circuit board (1102) arranged on the sheet body (1101). S5: Secondary punching On the first release film (2), double-sided adhesive (3), PI tape (4), FPC sheet (11), a continuous sheet edge cut line is generated near the outer edge of the first die-cut strip; An array of contour lines are punched out on the double-sided tape (3), PI tape (4), and FPC sheet (11) along the outer contour of the circuit board (1102); A secondary punched strip is obtained; S6: Secondary waste discharge The area between the edge of the secondary punching strip and the edge cut line of the adjacent sheet is designated as the outer scrap area of ​​the secondary punching; the area between the contour cut line and the edge cut line of the sheet is designated as the outer frame scrap area. Peel off the double-sided adhesive (3), PI tape (4), and waste material located in the outer frame waste area on the FPC sheet (11) from the top surface of the secondary punching strip; then peel off the second protective film (10) and discharge the first release film (2), double-sided adhesive (3), PI tape (4), and waste material located in the outer waste area of ​​the secondary punching on the FPC sheet (11).

2. The FPC web processing method according to claim 1, wherein Step S1 includes: rolling and bonding double-sided adhesive tape onto the first release film (2), peeling off the surface waste of the double-sided adhesive tape to obtain double-sided adhesive (3); then bonding PI tape (4) onto the double-sided adhesive (3) by synchronous rolling, and bonding the first protective film (1) onto the bottom surface of the first release film (2); then bonding the second release film (5) onto the PI tape (4) to form a die-cut material tape.

3. The FPC web processing method according to claim 2, wherein The double-sided adhesive tape used is 3M 467 type double-sided adhesive.

4. The FPC web processing method according to claim 2, wherein The PI tape (4) is either 3M 5419 type PI tape or 3M 5433 type PI tape.

5. The FPC web processing method according to claim 2, wherein The PI tape (4) is 3M 5433 type PI tape.

6. The FPC web processing method according to claim 1, wherein In step S2, the die-cutting blades used include a pair of inner cutters (6), an array of circular cutters (7), and an outer cutter (8). The inner cutters (6), the array of circular cutters (7), and the outer cutters (8) are arranged sequentially from the middle to both sides along the width direction of the die-cutting strip and are symmetrically arranged about the center line of the strip. The array of circular cutters (7) includes an array of circular cutters.

7. The FPC web processing method according to claim 6, wherein The array of circular cutters (7) includes circular cutters arranged in an inner and outer double-row array.

8. The FPC web processing method according to claim 1, wherein In step S4, the circuit board (1102) is provided in multiple ways and is arranged at intervals along the length direction on the center line of the sheet body (1101).

9. The method for processing FPC rolls according to claim 1, characterized in that, In step S5, the die-cutting blade used includes multiple contour cutters (9) adapted to the contour of the circuit board (1102), and sheet edge cutters (12) located on both sides of the multiple contour cutters (9).

10. The method of processing a roll of FPC according to claim 1, wherein After step S6, the product undergoes further rolling to obtain the FPC product.

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