CN1191746C - Production method of film type flexible circuit board - Google Patents

Abstract

A production method of film type flexible circuit board is characterized by that it uses a flexible insulating adhesive tape to make press-fit, etching and protective layer-forming engineering by means of linkage operation mode of winding wheel to winding wheel; and then, punching holes to form chain holes, cutting the flexible insulating tape along parallel lines arranged along the chain holes to form a plurality of flexible circuit tapes with smaller width, and winding the flexible circuit tapes on a winding wheel, wherein each flexible circuit tape is provided with a plurality of film type flexible circuit boards between the chain holes at two sides. The method has the effects of being suitable for producing film type flexible circuit boards with various widths and reducing the manufacturing cost.

Description

Production method of film type flexible circuit board

technical field

The present invention relates to a production method of a film-type flexible circuit board, in particular to a production method of a film-type flexible circuit board applied to electrical connectors and its products, such as the electrical connection between a display driver and a display panel , the electrical connection between foldable and bendable electronic components, and even as a chip carrier for semiconductor packaging [such as flip chip on the film [Chip On Film], or tape carrier package [Tape Carrier Package], suitable for flexible production Manufacture film-type flexible circuit boards of various widths.

Background technique

Flexible Printed Circuit Board [Flexible Printed Circuit, FPC] is flexible and bendable, and is widely used in the electrical connection between two electronic components. A flexible printed circuit board is disclosed in Taiwan Patent Publication No. 422933 The printed circuit board is installed in a liquid crystal display [Liquid Crystal Display; LCD] module, which is used as an electrical connection between the LCD panel and the rigid printed circuit board.

In China Taiwan Patent Publication No. 413997 and U.S. Patent No. 6,210,518, the manufacturing method of the flexible printed circuit board is disclosed, but the above-mentioned manufacturing method does not disclose the manufacturing process for mass production, because the flexible printed circuit board Manufacturing costs have not been effectively reduced; in addition, flexible printed circuit boards with a thickness of more than 0.2mm are no longer in line with the needs of advanced electronic products. How to mass-produce flexible printed circuit boards with a thickness of less than 0.2mm problems that urgently need to be solved.

Contents of the invention

The main purpose of the present invention is to provide a production method of a film-type flexible circuit board, which forms a metal circuit and a protective layer on a large-area flexible insulating tape by means of a rolling wheel corresponding to another rolling wheel. The flexible insulating tape is cut along the parallel lines arranged by the chain holes on both sides to form a plurality of flexible circuit tapes with smaller widths, which are rolled up on the reel to achieve a film type suitable for the production of various widths. The purpose of flexible circuit boards and reducing manufacturing costs.

The object of the present invention is achieved like this: a kind of production method of film type flexible circuit board is characterized in that: it comprises the steps:

(a) providing a flexible insulating tape which is wound up on a reel;

(b) Continuously pressing the copper foil on the flexible insulating tape, and continuously pressing the dry film on the copper foil, and setting the first reference point on the flexible insulating tape;

(c) After positioning with the first reference point, continuously expose the dry film to form a pattern;

(d) etching the copper foil to form a circuit pattern, and removing the dry film;

(e) Continuously affix the protective film on the flexible insulating tape. A reference hole is formed on the protective film, and the reference hole is aligned with the second reference point on the flexible insulating tape to press and position. protective layer on flexible insulating tape;

(f) Surface treatment of the flexible insulating tape to form an electroplating layer at the exposed part of the metal circuit;

(g) Perform a punching project to form even rows of chain holes on the flexible insulating tape, and cut or die-cut the flexible insulating tape along the parallel lines arranged by the chain holes to form multiple strips with a smaller width. A small flexible circuit tape is wound on another reel, and each flexible circuit tape has a plurality of film-type flexible circuit boards between the chain holes on both sides.

The steps (b) to (f) are repeated until there are proper layers of metal lines formed on the flexible insulating tape. After the punching and cutting step, an electrical inspection step is included to detect the flexible circuit tape and mark the position of defective products. The flexible insulating tape is one of tapes selected from polyimide, polyester, polyethylene terephthalate, liquid crystal polymer or Teflon. The protective film is one of polyimide and polyester. After the etching step, it further includes: setting a second reference point on the flexible insulating tape for positioning of the protective film.

The present invention also provides another production method of a film-type flexible circuit board, which comprises the following steps:

(a) providing a flexible insulating tape with copper foil formed on its surface and wound up on a reel;

(b) continuous pressing of the dry film on the flexible insulating tape;

(c) continuous exposure dry film;

(d) etching the copper foil to form a circuit pattern, and removing the dry film;

(e) forming a protective layer on the flexible insulating tape;

(f) surface treatment of the flexible insulating tape;

(g) Perform a punching project to form even rows of chain holes on the flexible insulating tape, and cut or die-cut the flexible insulating tape along the parallel lines arranged by the chain holes to form multiple strips with a smaller width. A small flexible circuit tape is wound on another reel, and each flexible circuit tape has a plurality of film-type flexible circuit boards between the chain holes on both sides.

The steps (b) to (f) are repeated until there are proper layers of metal lines formed on the flexible insulating tape. After the (g) punching and cutting step, an electrical inspection step is included to detect the flexible circuit tape and mark the position of defective products. The (e) step of forming a protective layer is selected from protective film bonding, green paint printing or green paint spraying. The flexible insulating tape is one of tapes selected from polyimide, polyester, polyethylene naphthalate, liquid crystal polymer or Teflon. The protective layer is one of polyimide, polyester or photosensitive solder resist green paint.

The present invention also provides a film-type flexible circuit board, which is characterized in that: it contains a flexible insulating layer; a plurality of metal circuits are formed on the flexible insulating layer; a protective layer is formed on the flexible insulating layer, the The protective layer has a hollow to expose the connecting end of the metal circuit; each serial film-type flexible circuit board is formed with chain holes on both sides.

The thickness of the soft insulating layer is 10-75 μm. The thickness of the plurality of metal lines is 5-40 μm. The protection layer is one selected from polyimide, polyester or photosensitive solder resist green paint; the thickness of the protection layer is 10-75 μm. The exposed connecting end of the metal circuit is formed with electroplating layer or protruding electrode.

The following describes in detail in conjunction with preferred embodiments and accompanying drawings.

Description of drawings

Fig. 1 is the flow block diagram of production method of the present invention;

Fig. 2 is the three-dimensional schematic view of the flexible insulating tape of the reel provided by the production method of the present invention;

Fig. 3 is a schematic side view of the flexible insulating tape of the present invention for continuously laminating copper foil;

Fig. 4 is a schematic side view of the continuous lamination dry film of the flexible insulating tape of the present invention;

Fig. 5 is a schematic side view of the flexible insulating tape of the present invention in the exposure step;

Fig. 6 is a schematic side view of the flexible insulating tape of the present invention in the etching step;

Fig. 7 is a schematic side view of the flexible insulating tape of the present invention in the bonding step;

Fig. 8 is a schematic side view of the surface treatment step of the flexible insulating tape of the present invention:

Fig. 9 is a schematic front view of the flexible insulating tape of the present invention in the punching and cutting step;

Fig. 10 is a schematic cross-sectional view of a film-type flexible circuit board produced by the production method of the present invention.

Detailed ways

Referring to shown in Figure 1, the production method of the film type flexible circuit board of the present invention comprises the following steps:

a. Provide soft insulating tape;

b. Continuous lamination of copper foil and continuous lamination of dry film;

c. Exposed dry film;

d. Etched copper foil;

e. Continuous lamination of protective film;

f. Surface treatment;

g. Punch holes to form chain holes, and cut soft insulating tape;

h. Electrical inspection.

As shown in FIG. 2, in (a) the step of providing a soft insulating tape, a soft insulating tape 20 is prepared, which is flexibly rolled up on a roll 11, and the soft insulating tape 20 is selected from poly Imide [polyimide, PI], polyethylene terephthalate [Polyethylene Terephalate, commonly known as (polyester" polyester, PET)], polyethylene naphthalate [Polyethylene naphthalate, PEN], liquid crystal polymer [Liquid Crystal Polymer, LCP] or Teflon [Teflon, PTFE] material, in this embodiment, the flexible insulating tape 20 is polyimide tape, its thickness is about 10-75 μ m, usually its thickness is about 25 μm.

As shown in Figure 3, in (b) the steps of continuous lamination of copper foil and continuous lamination of dry film, the first step is to roll out the flexible insulating tape 20 from one reel 11 and wind it up on the other reel 11 ', and the copper foil 30 [copper foil] is also rolled out by another reel 11", between the two reels 11, 11' is a pressing roller 12 [laminator], so that the copper foil 30 is pressed on The flexible insulating tape 20 is wound on another reel 11 ′, wherein the thickness of the copper foil 30 is between 5-40 μm, usually 18 μm.

As shown in Figure 4, afterwards, the flexible insulating tape 20 with copper foil 30 is rolled out from another reel 11, and a dry film 40 [dry film] is pressed with a pressing roller 12, wherein the dry The film 40 is a spin-sensitive film, such as a positive photoresist or a negative photoresist. After continuous lamination, the soft insulating tape 20 with the copper foil 30 and the dry film 40 is wound up on the reel 11, preferably , after pressing, set the first reference point 21 at a fixed distance, such as punching and setting positioning holes, etc., for the positioning of the step of exposing the dry film;

In another embodiment, the supplier can directly provide the flexible insulating tape 20 laminated with the copper foil 30 , and only the dry film 40 needs to be laminated in the step b and lamination.

As shown in Figure 5, in the step of (c) exposing the dry film, the flexible insulating tape 20 is rolled to an appropriate length and positioned according to the first reference point 21, and then developing (developing) is carried out so that the dry film 40 to form a patterned dry film 41, through the positioning of the first reference point 21, each exposed area of the flexible insulating tape 20 has a fixed distance from the adjacent exposed area, and each exposed area is consistent and neat Arrangement, there will be no bit shift.

As shown in Figure 6, in the step of (d) etching copper foil, it is to roll out the flexible insulating tape 20 with patterned dry film 41, and etch, for example, with copper chloride etching solution, to etch away The part not covered by the patterned dry film 41 makes the copper foil 30 form a patterned metal circuit 31; afterward, the patterned dry film 41 is removed by lye cleaning, so that the metal circuit 31 is exposed. After drying and setting the second reference point 22, it is rolled up to the reel 11.

As shown in Figure 7, in (e) the step of continuously affixing the protective film, it is to roll out the flexible insulating tape 20 formed with the metal circuit 31, and to continuously affix the protective film 50 in a thermocompression method to protect The film 50 is an insulating material selected from polyimide [polyimide, PI], polyester (polyester, PET), polyethylene naphthalate [Polyethylene naphthalate, PEN] or liquid crystal polymer [Liquid Crystal Polymer, LCP], Its thickness is about 10-75 μm, usually its thickness is about 25 μm. The protective film 50 is pre-formed with a hollow part 53 and a reference hole 52. When the reference hole 52 of the protective film 50 is aligned with the second layer of the flexible insulating tape The reference point 22 is pressed against the protective film 50 to form a protective layer 51 [cover layer] on the flexible insulating tape 20 to protect the metal circuit 31 and expose the connection end of the metal circuit 31; or, the protective layer 51 can also be formed by green paint printing [printingj or green paint spraying [Spray], and green paint is the abbreviation of Liquid Photomagible Solder Mask (LPSM). A hollow portion 53 is formed.

As shown in Figure 8, in the step of (f) surface treatment, it is to carry out electroplating, solder paste printing and heat-resistant and anti-rust treatment engineering to the soft insulating tape 20 with protective layer 51, so that the metal circuit 31 is exposed end to form a composite electroplating layer 32 or a protruding electrode, etc., wherein the formation of the electroplating layer 32 can be selected from methods such as electroless electroplating, gold electroplating or tin-lead electroplating, and is rolled up to a reel 11. Preferably, repeated execution ( Steps b)-(f), until the flexible insulating tape 20 has a proper number of metal lines formed on it.

As shown in Figure 9, in the step of (g) punching holes to form chain holes and cutting the flexible insulating tape, the surface-treated flexible insulating tape 20 is rolled out and punched to form even rows of relatively parallel chains. Cavities 61, for example, in this embodiment, the width of the flexible insulating tape 20 is enough to arrange three rows of film-type flexible circuit boards 62, and then set chain holes 61 on both sides of the film-type flexible circuit boards 62 in each row , and along the cutting parallel lines 23 arranged in the chain holes 61, the flexible insulating tape 20 is divided into strips by cutting [cutting] or punching [punching], so that it forms a plurality of flexible circuit tapes 60 with a smaller width, And rolled on the reel 13, and each flexible circuit tape 60 has a plurality of film-type flexible circuit boards 62 between the chain holes 61 on both sides;

After the flexible circuit tape 60 is formed, an electrical inspection step is performed to detect the flexible circuit tape 60 and mark the defective film-type flexible circuit board 62, usually after the defective film-type flexible circuit board 62 is punched. With the through hole, there is no need to separate or cut out the defective products, and the good products and marked defective products are wound up on the reel 13 .

Referring to Fig. 10, according to the production method of the above-mentioned film-type flexible circuit board, the flexible circuit tape 60 of multiple single-layer circuits can be prepared at the same time, and the cross-sectional structure of the film-type flexible circuit board 62 is as shown in Fig. 10 It shows that it not only has the advantages of mass production, but also can manufacture film-type flexible circuit boards of different width specifications (such as 35mm, 48mm, 70mm and other width specifications) with the same set of production equipment. For the flexible circuit board 62, an electrical insulating tape with a width of about 250mm is used to perform the previous steps such as (b) continuous pressing of copper foil and continuous pressing of dry film; (c) exposed dry film; (d) etching of copper foil; (e) continuous lamination of protective film; (f) surface treatment, etc., only need to change the cutting path of the cutting tool in the step of (g) punching to form chain holes and cutting the soft insulating tape to form a suitable width Flexible circuit tape, for example, is made of electrical insulating tape with a width of 250mm, which can be cut and divided into three rolls of 70mm width, four rolls of 48mm width or five rolls of 35mm width flexible circuit tape 60, so the present invention uses the same set of production equipment to mass-produce film-type flexible circuit boards of various widths and specifications, which has the effect of mass production and flexible manufacturing, and the prepared flexible circuit tape 60 is wound on the reel 13, which not only has low packaging cost, but also can Provided to customers for automated assembly.

As shown in Figure 10, according to the production method of the above-mentioned film-type flexible circuit board, the obtained film-type flexible circuit board 62 includes a flexible insulating layer 64, and its material is selected from polyimide [polyimide, PI], Polyester (polyester, PET), polyethylene naphthalate [Polyethylene naphthalate, PEN], liquid crystal polymer [Liquid Crystal Polymer, LCP] or Teflon [Teflon, PTFE] and other insulating materials, soft insulating layer 64 has a thickness of 10-75 μm, and a plurality of metal lines 31 and a protective layer 51 are formed on the flexible insulating layer 64, for example, bonding and laminating copper foil with adhesive 63, or the flexible insulating layer 64 is not covered. In the way of directly pressing the copper foil before curing, the thickness of the metal circuit 31 is 5-40 μm, and the thickness of the protective layer 51 is 10-75 μm, so the overall thickness of the film-type flexible circuit board 62 is thinner than 0.2mm, while the metal The circuit 31 is formed with an electroplating layer 32 or a protruding electrode in the hollow part 53 of the protective layer 51. Therefore, this film-type flexible circuit board 62 that can be mass-produced is extremely suitable as an electrical connector for a display panel and a printed circuit board. , are widely used in LCD monitors, notebook computers, PDAs and mobile phones, etc., and can even be used as chip carriers for semiconductor packaging.

The production method of the film-type flexible circuit board of the present invention can also repeat the above (b) continuous pressing of copper foil and continuous pressing of dry film; (c) exposed dry film; (d) etching of copper foil; (e) continuous pressing of dry film; The step of attaching the protective film and (f) the surface treatment, until the metal circuit with an appropriate number of layers is formed on the flexible insulating tape 20;

Afterwards, the steps of (g) punching holes to form chain holes and cutting the flexible insulating tape and (h) electrical inspection are performed to prepare a plurality of flexible circuit tapes 60 with a multi-layer circuit structure.

The present invention is only illustrated with preferred embodiments, and any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention belong to the protection scope of the present invention.

Claims (5)

1, a kind of production method of film-like flexible circuit board, it is characterized in that: it comprises the steps:

(a) provide a soft insulating tape, it is to furl on a rolling wheel;

(b) the pressing Copper Foil reaches continuous pressing dry film on this Copper Foil on this soft insulating tape continuously, and this soft insulating tape also is set with first datum mark;

(c) with behind first datum mark location, exposure dry film and form pattern continuously;

(d) etching Copper Foil and form line pattern, and remove this dry film;

(e) fit the protection film continuously on this soft insulating tape, be formed with datum hole on this protection film, this datum hole is aimed at the second datum mark pressing location of being located on this soft insulating tape, is formed in the protective layer on this soft insulating tape;

(f) this soft insulating tape of surface treatment makes the place of appearing of metallic circuit form electrodeposited coating;

(g) carry out the punching engineering, form the chain cave of even rows at this soft insulating tape, and the parallel lines of arranging along the chain cave are with cutting or this soft insulating tape of die-cut itemize, make it constitute the many flexible circuit adhesive tapes that width is less, and furl in other rolling wheel, this each flexible circuit adhesive tape has most the film-like flexible circuit boards between two side chain caves.

2, the production method of film-like flexible circuit board according to claim 1 is characterized in that: repeat this (b) to (f) step, be formed at this soft insulating tape up to the metallic circuit that the suitable number of plies is arranged.

3, the production method of film-like flexible circuit board according to claim 1 is characterized in that: after this punching cutting step, other includes the electric checking step, with detection flexible circuit adhesive tape, and the position of sign defective products.

4, the production method of film-like flexible circuit board according to claim 1 is characterized in that: this soft insulating tape is to be selected from one of them of pi, polyester, poly-adhesive tape to naphthalenedicarboxylic acid second diester, liquid crystal polymer or Teflon.

5, the production method of film-like flexible circuit board according to claim 1 is characterized in that: this protection film is to be selected from one of them of pi or polyester.

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