CN109451675B

CN109451675B - Auxiliary material transfer process

Info

Publication number: CN109451675B
Application number: CN201811148220.3A
Authority: CN
Inventors: 徐承升; 廖发盆; 张伟; 吴美丽; 程胜周
Original assignee: DONGGUAN COJOIN CIRCUITS Co Ltd
Current assignee: DONGGUAN COJOIN CIRCUITS Co Ltd
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-01-07
Anticipated expiration: 2038-09-29
Also published as: CN109451675A

Abstract

The invention relates to the technical field of flexible circuit board production processes, in particular to an auxiliary material transfer process, which comprises the following steps: s1, performing primary stamping treatment on the base material, stamping part of waste around the FPC, and reserving a plurality of connecting positions for connecting the FPC and the residual waste; s2, drilling at least two first positioning holes on the film; s3, positioning the film through the first positioning hole, and then attaching the film to the surface of the base material; s4, performing secondary stamping treatment on the base material adhered with the film, stamping the connecting positions on the base material, and tearing the residual waste materials from the film to obtain a plurality of FPCs adhered to the film; s5, drilling a second positioning hole matched with the first positioning hole on the auxiliary material; s6, after the second positioning hole of the auxiliary material is opposite to the first positioning hole of the film on the side, far away from the film, of the FPC, the auxiliary material is attached to the film, the FPC is located between the film and the auxiliary material, the auxiliary material is attached to four rows of FPCs simultaneously, and finally the product is delivered.

Description

Auxiliary material transfer process

Technical Field

The invention relates to the technical field of flexible circuit board production processes, in particular to an auxiliary material transfer process.

Background

The Flexible Printed Circuit board (FPC) is a Flexible Printed Circuit board made of polyimide or polyester film as a base material, has high reliability and is excellent in flexibility, and has the characteristics of high wiring density, light weight, thin thickness and good bending property.

At present, when the FPC is produced, the base material is generally punched to form the base material into a single FPC, then the single FPC is delivered or the FPC is delivered after being singly packaged by film sticking, and because the single FPC has small volume and light weight, the manufactured FPC is easy to cause partial loss or the stacked FPCs are easy to wear when being stored or transported, and the product quality is influenced.

Disclosure of Invention

The invention aims to provide an auxiliary material transfer process, which realizes simultaneous shipment of a plurality of FPCs, is not easy to lose or wear the FPCs, is simple in operation method and is beneficial to improving the product quality.

In order to solve the technical problems, the invention adopts the following technical scheme: an auxiliary material transfer process comprises the following steps:

s1, performing primary stamping treatment on a base material, wherein the base material comprises a plurality of FPCs (flexible printed circuits) arranged in an array manner and waste materials surrounding the FPCs, the waste materials are connected with the FPCs, partial waste materials around the FPCs are stamped out firstly, and a plurality of connecting positions for connecting the FPCs and the residual waste materials are reserved;

s2, drilling at least two first positioning holes on the film;

s3, positioning the film through the first positioning hole, and then attaching the film to the surface of the base material;

s4, performing secondary stamping treatment on the base material adhered with the film, stamping the connecting positions on the base material, and tearing the residual waste materials from the film to obtain a plurality of FPCs adhered to the film;

s5, drilling a second positioning hole matched with the first positioning hole on the auxiliary material;

s6, after the second positioning hole of the auxiliary material is opposite to the first positioning hole of the film on the side, far away from the film, of the FPC, the auxiliary material is attached to the film, the FPC is located between the film and the auxiliary material, the auxiliary material is attached to four rows of FPCs simultaneously, and finally the product is delivered.

According to the invention, the base material is subjected to primary stamping treatment and secondary stamping treatment after the base material is pasted with the film, so that a plurality of FPCs are orderly pasted on the film in an array manner, the simultaneous delivery of the plurality of FPCs is realized, and the delivery efficiency is improved; auxiliary materials are attached to one side, away from the film, of the FPC, the auxiliary materials are attached to four rows of FPCs on the film at the same time, the auxiliary materials protect the FPC and can prevent the FPC from being worn in the process of shipment, transportation or storage; through set up two at least first locating holes on the film and set up the second locating hole on the auxiliary material, conveniently laminate film and auxiliary material on the substrate fast and accurately, improved production efficiency, can guarantee product quality's stability simultaneously.

The film comprises a bearing film, an aging-resistant adhesive layer and an easily-peelable adhesive layer which are sequentially compounded from bottom to top.

Through compounding ageing-resistant viscose layer and easily peeling off the viscose layer in proper order on the bearer film, when the film was torn from FPC, cull or fold phenomenon can not appear in the FPC surface, and when setting up of ageing-resistant viscose layer made the film tear from FPC, easily peeled off the viscose layer and be difficult for breaking away from the bearer film and adhere to FPC surface messenger FPC surface and produce the cull.

Wherein the bearing film is one of PVA, PET, BOPP, PE, PC, PS and CPP films with the thickness of 60-70 mu m.

The FPC is generally made of polyimide or polyester film serving as a base material, the thickness is only dozens of microns generally, and the base material is too soft and thin, so that the quality of a product is reduced or the product is scrapped due to the fact that the product is prone to wrinkling in the preparation, storage or carrying processes. When the thickness of the carrier film is less than 60 μm, the carrier film is easily wrinkled.

The anti-aging adhesive layer is prepared from the following raw materials in parts by weight:

the epoxy resin has excellent physical property, bonding property and adhesiveness, the epoxy resin is compounded with the polyurethane resin with high strength, tear resistance and wear resistance to prepare the colloid with excellent adhesion property, bonding property and wear resistance, and when the prepared colloid is coated on the surface of the bearing film, the hardness and wear resistance of the bearing film are favorably improved, so that the prepared film has certain stiffness, is not easy to wear and is favorable for protecting an FPC (flexible printed circuit); the aging-resistant adhesive layer is prepared by adding the aging-resistant auxiliary agent into the epoxy resin and polyurethane resin composite colloid, so that the aging phenomenon of the aging-resistant adhesive layer is not easy to occur, the service life of the colloid is prolonged, and the colloid keeps good peel strength.

The easy-to-peel layer is prepared from the following raw materials in parts by weight:

the anti-sticking filler is a mixture of silicon dioxide and lignin powder according to a weight ratio of 1: 3.

The prepared easy-to-peel adhesive layer is more sensitive to ultraviolet light by adding the acrylic acid monomer, the prepolymer and the photoinitiator, and the easy-to-peel adhesive layer is easy to age when the ultraviolet light irradiation time is longer. Epoxy and polyurethane resin are compounded to be favorable for improving the viscosity and the adhesive force of the colloid, so that the easy-to-peel adhesive layer after primary curing can be firmly adhered with the FPC, and the FPC is not easy to separate from the rubber sheet. Silica and lignin powder among the anti-sticking filler take place bridging effect easily and form stable crosslinked network structure in the resin colloid in the resin system, not only can be fine after easy peel viscose layer is ageing separate colloid and FPC, and be favorable to improving the hardness of easy peel viscose layer, make the film that makes have certain stiffness, be difficult for appearing the fold, and lignin powder is better with the compatibility of resin colloid, mix it with silica not only can reduce the addition of silica, make the colloid that makes have suitable hardness and pliability, and simultaneously, still be favorable to improving the viscidity and the adhesive force of the colloid of preliminary curing.

The particle size of the silicon dioxide is 100-200nm, and the particle size of the lignin powder is 50-60 nm.

Adopt the anti-sticking filler of above-mentioned particle diameter, the colloid that makes easy peel adhesion layer has good viscidity before carrying out ultraviolet irradiation, make FPC be difficult for taking place to break away from with the film, simultaneously, after easy peel adhesion layer carries out ultraviolet irradiation, easy peel adhesion layer takes place to shrink, make partly anti-sticking granule expose in the colloid surface, and then reduce the area of contact of FPC and colloid, reduce the adhesive force between colloid and the FPC, it can easily be peeled off from the film to FPC, and there is not the cull phenomenon.

The prepolymer is a mixture of 2-3:1-6:3 parts by weight of polyurethane acrylate, epoxy acrylate and organic silicon acrylate.

The epoxy acrylate is high in curing speed, good in adhesive property, high in gloss, high and low temperature resistance of organic silicon acrylate and excellent in flexibility, the polyurethane acrylate is good in comprehensive performance, the epoxy acrylate, the organic silicon acrylate and the polyurethane resin are mixed according to the proportion to prepare a colloid which is excellent in thermal stability, high in adhesive force and excellent in mechanical property, the FPC is not prone to being separated from a film, and the anti-aging adhesive layer prepared from the prepolymer is high in photocuring speed, so that the FPC is convenient to strip from the film.

Wherein the photoinitiator is a mixture of benzophenone and triethylamine according to the weight ratio of 1-3: 0.1-0.2.

The composite photoinitiator is low in price, good in stability and high in initiation efficiency, the colloid is convenient to store for a long time, the photocuring efficiency is favorably improved, the volume shrinkage range of the solidified colloid is large, part of the anti-sticking filler can be exposed out of the surface of the colloid after solidification, and the FPC is convenient to strip from the rubber sheet.

Wherein the anti-aging auxiliary agent is a mixture consisting of an antioxidant and an ultraviolet absorber.

Tests show that the composite anti-aging system formed by compounding the antioxidant and the ultraviolet absorbent has obvious synergistic effect, can improve the heat resistance stability and the light stability of the colloid, effectively inhibits the thermal aging degradation and the light aging degradation of the colloid, and prolongs the service life of the colloid.

The antioxidant is at least one of antioxidant DLTP, antioxidant CA, p-hydroxyanisole, hydroquinone and 2-tert-butylhydroquinone, and the ultraviolet absorbent is at least one of ultraviolet absorbent BAD, ultraviolet absorbent 327 and ultraviolet absorbent 326.

The compatilizer is at least one of hydrogenated styrene-butadiene-styrene copolymer grafted glycidyl methacrylate, ethylene-methyl acrylate grafted glycidyl methacrylate and styrene-acrylonitrile copolymer grafted glycidyl methacrylate.

By adopting the compatilizer of the kind, the compatilizer can be matched with other raw materials and can perform synergistic reaction, the interfacial tension between molecules when the epoxy resin, the polyurethane resin and other raw materials react is effectively reduced, the interfacial bonding force is further improved, the dispersed phase and the continuous phase are uniform, a stable structure is formed, the mutual matching reaction of all raw materials of the colloid of the aging-resistant adhesive layer is promoted, the adhesive property and the wear resistance of the colloid are improved, and the processing rheological property is improved.

The coupling agent is at least one of vinyl triethoxysilane, aniline methyl triethoxysilane, gamma-methacryloxypropyl trimethoxysilane, methyl triethoxysilane, pyrophosphate titanate and vinyl tri (beta-methoxyethoxy) silane.

The organic solvent is at least one of benzene, toluene, ethyl acetate and xylene.

The thickness of the anti-aging adhesive layer is 5-8 μm, and the thickness of the easy-to-tear adhesive layer is 3-4 μm.

The easy-to-peel adhesive layer and the ageing-resistant adhesive layer of above-mentioned thickness make the film that makes have higher stickness and adhesive force, and FPC is difficult for breaking away from the film, and when ageing-resistant adhesive layer thickness was too big, the ultraviolet irradiation time that will make anti-sticking granule expose the colloid surface needs was longer, not only influences production efficiency, and long-time ultraviolet irradiation probably influences the stickness and the adhesive force on ageing-resistant adhesive layer. When the aging-resistant adhesive layer and the easy-to-tear adhesive layer are too thin, the peeling strength is too low, and the FPC is easy to separate from the film.

The invention has the beneficial effects that: the process can realize the simultaneous shipment of a plurality of FPCs, has high shipment efficiency, and can ensure that the film and the auxiliary materials can be accurately attached to the FPCs through the first positioning hole and the second positioning hole, thereby being beneficial to improving the attachment efficiency; the rubber sheet and the auxiliary materials are covered on the surface of the FPC, so that the FPC is not easy to abrade with equipment, and the quality of a finished product is stable; the easy-to-peel adhesive layer is prepared by compounding epoxy resin, polyurethane resin and prepolymer and adding anti-adhesion filler and photoinitiator, so that the colloid of the easy-to-peel adhesive layer is easy to age and shrink under the irradiation of ultraviolet light, the anti-adhesion particles are exposed on the surface of the colloid, the bonding strength between the colloid and the FPC is reduced, the FPC can be quickly peeled off from the rubber sheet, no residual glue is attached to the FPC, the anti-aging adhesive layer is compounded between the easy-to-peel adhesive layer and the bearing film, the anti-aging adhesive layer of the rubber sheet still has good adhesive force and viscosity under the irradiation of the ultraviolet light, and the easy-to-peel adhesive layer is not easy to separate from the bearing film.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions 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 to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic view of a substrate structure according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an embodiment of the present invention in which auxiliary materials and films are respectively coated on and under a plurality of FPCs.

Description of reference numerals: 1. a connection bit; 2. FPC; 3. waste materials; 4. a first positioning hole; 5. an auxiliary material; 6. a film; 7. a substrate.

Detailed Description

In order to facilitate the understanding of those skilled in the art, the present invention will be further described with reference to examples 1 to 3 and fig. 1 to 2, and the description of the embodiments is not intended to limit the present invention.

Example 1

An auxiliary material transfer process is shown in figures 1-2 and comprises the following steps:

s1, performing primary stamping treatment on a base material 7, wherein the base material 7 comprises a plurality of FPCs 2 arranged in an array manner and waste materials 3 surrounding a plurality of FPCs 2, the waste materials 3 are connected with a plurality of FPCs 2, a part of the waste materials 3 surrounding a plurality of FPCs 2 are stamped, and a plurality of connecting positions 1 for connecting the FPCs 2 and the residual waste materials 3 are reserved;

s2, drilling two first positioning holes 4 (not marked in the figure) on the film 6;

s3, positioning the film 6 through the first positioning hole 4, and then attaching the film 6 to the surface of the base material 7;

s4, carrying out secondary stamping treatment on the base material 7 adhered with the film 6, stamping the connecting position 1 on the base material 7, and tearing the residual waste material 3 from the film 6 to obtain a plurality of FPC2 adhered on the film 6;

s5, drilling a second positioning hole matched with the first positioning hole 4 on the auxiliary material 5;

s6, after the second positioning hole of the auxiliary material 5 is over against the first positioning hole 4 of the film 6 on the side, far away from the film 6, of the FPC2, the auxiliary material 5 is attached to the film 6, the FPC2 is located between the film 6 and the auxiliary material 5, the auxiliary material 5 is attached to four rows of FPCs 2 at the same time, and finally the product is delivered.

Wherein, the base material 7 is a polyimide film with the thickness of 50 μm, and the auxiliary material 5 is a PVA film with the thickness of 60 μm.

The film 6 comprises a bearing film, an aging-resistant adhesive layer and an easy-to-peel adhesive layer which are compounded in sequence from bottom to top, wherein the bearing film is a PET film with the thickness of 60 mu m.

The anti-aging adhesive layer is composed of the following raw materials in parts by weight:

the anti-aging auxiliary agent is a mixture of an antioxidant DLTP and an ultraviolet absorber 326 in a weight ratio of 3: 2. The compatilizer is hydrogenated styrene-butadiene-styrene copolymer grafted glycidyl methacrylate, the coupling agent is vinyl triethoxysilane coupling agent, and the organic solvent is benzene.

The easy-to-peel layer is composed of the following raw materials in parts by weight:

the anti-sticking filler is a mixture of silicon dioxide and lignin powder in a weight ratio of 1:3, the particle size of the silicon dioxide is 100nm, and the particle size of the lignin powder is 50 nm.

The prepolymer is a mixture of polyurethane acrylate, epoxy acrylate and organic silicon acrylate according to the weight part of 2:1: 3.

The photoinitiator is benzophenone, triethylamine, diethoxyacetophenone and benzoin dimethyl ether in a weight ratio of 1:0.1: 2: 4, and (b) a mixture of the components.

The preparation method of the film 6 comprises the following steps:

(1) coating an ageing-resistant adhesive layer: mixing epoxy resin, polyurethane resin, an anti-aging auxiliary agent, a coupling agent, a compatilizer and an organic solvent according to parts by weight, uniformly stirring to prepare an anti-aging adhesive, coating the anti-aging adhesive layer on a bearing film, and curing for 10min at 50 ℃ to prepare the anti-aging adhesive layer;

(2) coating an easy-to-peel adhesive layer: adding epoxy resin, polyurethane resin, acrylic acid monomer, prepolymer, photoinitiator and anti-sticking filler into dimethylbenzene according to parts by weight, uniformly stirring to prepare an easy-peeling adhesive, coating the prepared easy-peeling adhesive on the surface of the anti-aging adhesive layer obtained in the step (1), then placing the coated carrier film into an ultraviolet curing box for curing, and then taking out to prepare a rubber sheet 6; the curing conditions were 1000W mercury lamp, the irradiation distance was 40cm, and the curing time was 20 s.

Example 2

s2, drilling two first positioning holes 4 on the film 6;

The film 6 comprises a bearing film, an aging-resistant adhesive layer and an easily-peelable adhesive layer which are compounded from bottom to top in sequence, wherein the bearing film is a BOPP film with the thickness of 65 mu m.

the anti-aging auxiliary agent is a mixture of an antioxidant CA and an ultraviolet absorbent BAD in a weight ratio of 5:3. The compatilizer is styrene-acrylonitrile copolymer grafted glycidyl methacrylate, the coupling agent is aniline methyl triethoxy silane coupling agent, and the organic solvent is toluene.

the anti-sticking filler is a mixture of silicon dioxide and lignin powder in a weight ratio of 1:3, the particle size of the silicon dioxide is 150nm, and the particle size of the lignin powder is 55 nm. .

The prepolymer is a mixture of polyurethane acrylate, epoxy acrylate and organic silicon acrylate according to the weight part of 2.5:3.5: 3.

The photoinitiator is benzophenone, triethylamine, diethoxyacetophenone and benzoin dimethyl ether in a weight ratio of 2:0.15: 2: 5, and (c) a mixture of the components.

The preparation method of the film 6 comprises the following steps:

Example 3

s2, drilling two first positioning holes 4 on the film 6;

The film 6 comprises a bearing film, an aging-resistant adhesive layer and an easily-peelable adhesive layer which are compounded from bottom to top in sequence, wherein the bearing film is a PE film with the thickness of 70 mu m.

the anti-aging auxiliary agent is a mixture of hydroquinone antioxidant and ultraviolet absorber 327 in a weight ratio of 7: 4. The compatilizer is ethylene-methyl acrylate grafted glycidyl methacrylate, the coupling agent is methyl triethoxysilane coupling agent, and the organic solvent is ethyl acetate.

the anti-sticking filler is a mixture of silicon dioxide and lignin powder in a weight ratio of 1:3, the particle size of the silicon dioxide is 200nm, and the particle size of the lignin powder is 60 nm.

The prepolymer is a mixture of polyurethane acrylate, epoxy acrylate and organic silicon acrylate according to the weight part of 3:6: 3.

The photoinitiator is benzophenone, triethylamine, diethoxyacetophenone and benzoin dimethyl ether according to a weight ratio of 3:0.2: 2: 6.

The preparation method of the film 6 comprises the following steps:

Comparative example

The comparative example differs from example 2 in that it does not have an anti-stick filler added.

The sheets 6 obtained in examples 1 to 3 and comparative example were attached to a 50 μm thick polyimide film, the width of the sheet 6 being 25mm, and then the following performance tests were performed, and the test results were recorded in table 1.

(1) And (3) stability testing: the initial 180 DEG peel strength of the film and the 180 DEG peel strength after one, two and four days were measured according to the GB/T2792-1998 standard using an electron tensile machine with a peel rate of 300 mm/min.

(2) And (3) pollution test: the film 6 is attached to the polyimide film, then the polyimide film is placed in an ultraviolet curing device, a 5000W ultraviolet curing lamp is adopted, the irradiation distance is 40cm, after 1h of irradiation, 180-degree peel strength of the aged film is tested, the film 6 is slowly peeled off by hands, and whether the residual glue exists on the surface of the FPC or not is observed.

According to the test, the following results are obtained: the adhesive sheet 6 prepared in examples 1 to 3 has a high peel strength, an initial 180 ° peel strength of 4.0 to 5.0N/25mm, and good adhesion properties, and the adhesive sheet 6 is not easily detached from the polyimide film, which is advantageous for protecting the FPC2, so that the FPC2 is regularly arranged on the adhesive sheet 6; the rubber sheet 6 prepared in the embodiments 1-3 has good colloidal stability, and is not easy to age and stick; as can be seen from examples 1 to 3 compared with the comparative example, due to the addition of the anti-adhesion filler, after the irradiation of high-power ultraviolet light, the volume of the colloid of the easy-to-peel adhesive layer shrinks, so that the anti-adhesion particles are exposed on the surface of the colloid, the adhesion area between the colloid of the easy-to-peel adhesive layer and the FPC2 is reduced, the adhesion force between the FPC2 and the film 6 is further reduced, the FPC2 is conveniently peeled off from the film 6, and no residual adhesive appears on the surface of the peeled FPC 2.

The above embodiments are preferred implementations of the present invention, and the present invention can be implemented in other ways without departing from the spirit of the present invention.

Claims

1. An auxiliary material transfer process is characterized in that: the method comprises the following steps:

s2, drilling at least two first positioning holes on the film;

s6, after a second positioning hole of the auxiliary material is over against the first positioning hole of the film on the side, far away from the film, of the FPC, the auxiliary material is attached to the film, the FPC is located between the film and the auxiliary material, the auxiliary material is attached to four rows of FPCs simultaneously, and finally the product is delivered;

the film comprises a bearing film, an aging-resistant adhesive layer and an easily-peelable adhesive layer which are sequentially compounded from bottom to top;