WO2020140855A1

WO2020140855A1 - Printing technology for full lamination method

Info

Publication number: WO2020140855A1
Application number: PCT/CN2019/129599
Authority: WO
Inventors: 李瑞江
Original assignee: 苏州桐力光电股份有限公司
Priority date: 2018-12-30
Filing date: 2019-12-28
Publication date: 2020-07-09
Also published as: CN109772660B; CN109772660A

Abstract

Disclosed is a printing technology for a full lamination method. A screen frame (4) is comprised, the screen frame (4) is provided with a bottom frame (2) for being attached to the surface of a product (1) to be printed with glue (3), an inner side edge of the bottom frame (2) encloses to form a glue application area (5), the surface of the product (1) to be printed with the glue (3) is provided with an area to be glued (6), the shape of the glue application area (5) is the same as that of the synchronously reduced area to be glued (6), the distance between the inner side edge of the bottom frame (2) and a corresponding side edge of the area to be glued (6) on the surface of the product (1) to be printed with the glue (3) is 1.3 to 1.7 mm, and the viscosity of the glue (3) is 40,000 to 50,000 centipoises. When the glue (3) is printed, the screen frame (4) is aligned with and presses down the product (1) to be printed with the glue (3); afterwards, the glue (3) is applied to the glue application area (5) of the screen frame (4); then, the glue is scraped with a scraper, and part of the glue (3) enters the position between the screen frame (4) and the surface of the product (1) to be printed with the glue (3); and finally, pre-curing is carried out. The technology can prevent glue deficiency while ensuring the amount of excess glue.

Description

A printing process for full-fitting method

Technical field

The invention relates to a printing process for a full bonding method, which belongs to the technical field of full bonding technology.

Background technique

The structure of the traditional touch display screen is generally composed of three pieces: CG + touch screen + LCD screen, which needs to be laminated twice during the assembly process. Among them, the bonding of the touch screen and the LCD screen generally adopts the frame sticker (double-sided adhesive tape), and there is an air layer between the LCD screen and the touch screen. Because the refractive index of air and glass are different, each time light passes through the interface of glass and air, it will cause a reflection. The more interface layers, the more reflections will occur, resulting in the loss of the light source provided by the backlight of the LCD screen. At the same time, the external light will be reflected by these interface layers, resulting in glare, which affects the customer's use. In addition, the three modules need to be pasted twice, the cost is high, the process is numerous, and the defects are relatively large.

As an improvement of the bonding method, mobile phone screen manufacturers use LOCA (Liquid Optical Clear Adhesive, liquid optical adhesive) to fully bond the CG and the liquid crystal screen, because the refractive index of the cured LOCA optical adhesive is almost the same as the glass, and the bonding The thickness after the control is usually about 0.1mm ~ 0.2mm, so the screen adopting this technology has the advantages of lightness, thinness, and good display effect.

The full lamination technology is divided into scraping glue process, OCA full lamination and LOCA full lamination. OCA (Optically Clear Adhesive, OCA Optical Adhesive) full lamination is the use of an optically transparent layer of special double-sided adhesive to bond the two surfaces. Advantages: cheap price and convenient operation. Disadvantages: It is easy to produce tape wrinkles and bubbles, resulting in shortcomings such as low yield, difficult defoaming, high cost, and low repair success rate. LOCA (water glue bonding) is the use of liquid glue to bond two surfaces. Its cost is more expensive than OCA full-laminated products. The disadvantages are low efficiency, excessive glue overflow, and difficulty in cleaning. The thickness of the squeegee process is too thick to be thin.

The invention patent with publication number CN106739415A discloses an improved full lamination process implementation method, which is characterized by the following steps: (1) In a vacuum environment, using screen printing coating technology, screen It is covered with dense and uniform small holes, so that the UV glue flows from these dense holes to the printing surface of the CG screen, so that the printing surface of the CG screen is covered with dense and uniform dot-shaped UV glue, which can control the UV glue very well. The amount of coating to prevent the overflow of UV glue; (2), stick the CG screen and the LCD substrate together: use the bonding equipment to place the CG screen with the bonding surface facing down and fix it, and the LCD bonding surface slowly after positioning It rises, and finally stays in a fixed gap. Through the capillary principle, it spreads evenly to the four edges of the gap. The thickness of the gap is usually 0.1mm-0.2mm; (3) UV curing process, including the following steps: (3.1) 、Fix two points on the diagonal of the product for pre-curing; (3.2), use UV light irradiation device on the front of the LCD substrate to achieve UV curing, curing the product after reliability test; (3.3) 1. Reverse UV irradiation on the reverse side of the LCD substrate, (3.4), add a UV light irradiation device on the FPC side of the LCD substrate, and irradiate the uncured UV glue that is not irradiated from the front side from the side; (3.5). Heat fast, well ventilated metal tray for heat drying.

Summary of the invention

In order to overcome the above-mentioned shortcomings in the prior art, the present invention aims to provide a printing process for a full lamination method.

In order to achieve the above object and other related objects, the technical solution provided by the present invention is: a printing process for a full lamination method, including a screen frame, the screen frame having a surface paste for the product to be printed with glue A bottom frame, the inner side of the bottom frame encloses to form a glue area, the surface of the product to be printed with glue has an area to be glued, and the shape of the glue area is that the area to be glued shrinks simultaneously Shape, and the inner side of the bottom frame is 1.3-1.7mm away from the corresponding side of the glue area of the surface of the product to be printed with glue, the viscosity of the glue is 40000-50000 centipoise; The frame is pressed down on the product to be printed with glue, and then the glue is applied to the glued area of the screen frame, and then the glue is scraped with a scraper. Part of the glue enters between the frame and the surface of the product to be printed with glue. Curing.

The preferred technical solution is: the glue is a transparent silicone gel that can be cured by ultraviolet light and heating, and its raw material formulation includes the following parts by weight of raw materials:

Wherein, both the component A and the component B are (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 terminated linear structure polysiloxane, and the viscosity of the component A is 50000-150000 centipoise , The viscosity of the component B is 300-10000 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is Compounds conforming to general formula (1):

Among them, R ₁ , R ₂ and R ₃ are all hydrogen groups, 100≥m≥20, n≥1.

A preferred technical solution is: the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 3000-5000 ppm; the amount of platinum metal is 2-20 ppm of the total mixing amount of the raw material formula.

A preferred technical solution is that the inhibitor is at least one of 3-methyl-1-butyn-3-ol, 1-ethynylcyclohexanol and tetravinylcyclotetrasiloxane.

A preferred technical solution is: the component C is at least one of vinyl-terminated polysiloxane, MDT phenyl silicone resin, MT silicone resin and MQ silicone resin.

A preferred technical solution is: the MQ silicone resin is MQ vinyl polysiloxane, and the molar ratio of M units and Q units is 0.75-1.0.

A preferred technical solution is: the component A is a compound that meets the general formula (2):

Among them, R4 and R5 are vinyl groups, and x is greater than or equal to 1000.

A preferred technical solution is: the component B is a compound that meets the general formula (2):

Among them, R4 and R5 are vinyl groups, x=50-2000.

The preferred technical solution is: the adhesion promoter is γ-glycidyloxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, γ-methyl At least one of acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

Due to the application of the above technical solutions, the present invention has the following advantages over the prior art:

1. The viscosity of the glue of the invention is 40,000-50000 centipoise, which can ensure that the glue will not flow.

2. The size of the glued area of the screen frame matches the size of the glued area of the product to be printed with glue, and the inner side of the bottom frame is separated from the corresponding side of the glued area of the surface of the product to be printed with glue by 1.3-1.7 mm, which can ensure that the amount of glue overflowing will not be short of glue.

3. The glue is made of UV-curable and heated dual-curing transparent silicone gel with high viscosity. The sizing process is stencil printing with good formability; without UV light, it will not cure at room temperature or medium temperature; but after UV light is short After the time light is triggered, it will start curing, and the heating conditions can accelerate the curing speed, thereby effectively solving the problem that the UV glue does not cure in the "blind area" of the light during the use (the backlight module is bonded to the cover plate during the full bonding of the LED screen) The UV glue of the opaque area cannot be cured due to the lack of ultraviolet light), and the rapid curing of the "blind area" UV glue can be achieved by short-term heating (T<70℃, t<5min), which is beneficial to improve Productivity.

BRIEF DESCRIPTION

Figure 1 is a schematic diagram of the printing structure.

FIG. 2 is a schematic diagram 1 of the relative relationship between the glued area and the area to be glued.

FIG. 3 is a second schematic diagram of the relative relationship between the glued area and the area to be glued.

In the above drawings, 1. the product to be printed with glue; 2. the bottom frame; 3. the glue; 4. the screen frame; 5. the glue area; 6. the area to be glued.

detailed description

The following describes the implementation of the present invention by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

Please refer to Figure 1-3. It should be noted that the structure, ratio, size, etc. shown in the drawings of this specification are only used to match the contents disclosed in the specification, for those familiar with this technology to understand and read, not to limit the implementation of the present invention Limited conditions, so it has no technical significance. Any modification of structure, change of proportional relationship or adjustment of size should still fall within the scope of the present invention without affecting the efficacy and purpose of the present invention. The disclosed technical content can be covered. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this manual are only for the convenience of description, not to limit this. The range in which the invention can be implemented, and changes or adjustments in its relative relationship, without substantial changes in the technical content, should also be regarded as the scope of the invention.

Example 1: A printing process for a full lamination method

A printing process for a full lamination method includes a screen frame 4 having a bottom frame 2 for bonding to the surface of the product 1 to be printed with glue, and the inner side of the bottom frame is enclosed A glue application area 5 is formed. The surface of the glue product to be printed has a glue application area 6. The shape of the glue application area is a shape that simultaneously shrinks the glue application area. The sides of the glue area of the surface of the product for printing glue are 1.5mm apart, and the viscosity of the glue is 40,000-50000 centipoise; when printing the glue, press the product to be printed with the frame of the frame and press the glue Fill the glued area of the screen frame, then scrape the glue with a scraper, part of the glue enters between the screen frame and the surface of the product to be printed with glue, and finally pre-cures. The screen frame 4 of the present invention is not provided with a silk screen.

The preferred embodiment is: the glue is a transparent silicone gel that can be cured by ultraviolet light and heating, and its raw material formulation includes the following parts by weight of raw materials:

Wherein, both the component A and the component B are (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 end-capped linear structure polysiloxane, and the viscosity of the component A is 100000 centipoise. The viscosity of the component B is 5000 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is in accordance with the general formula ( 1) Compound:

Among them, R ₁ , R ₂ and R ₃ are all hydrogen groups, m=60 and n=5.

A preferred embodiment is: the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 4000 ppm; the amount of platinum metal is 11 ppm of the total amount of the raw material formulation.

A preferred embodiment is that the inhibitor is 3-methyl-1-butyn-3-ol.

A preferred embodiment is: the component C is a mixture composed of vinyl-terminated polysiloxane and MDT phenyl silicone resin in a mass ratio of 1:5.

A preferred embodiment is: the component A is a compound that meets the general formula (2):

Among them, R4 and R5 are vinyl groups, and x is equal to 1500.

A preferred embodiment is: the component B is a compound that meets the general formula (2):

Among them, R4 and R5 are vinyl groups, x=400.

A preferred embodiment is that the adhesion promoter is γ-glycidyloxypropyltrimethoxysilane.

The raw materials of the invention are easily available, the production process is simple and controllable, and are suitable for industrial large-scale production; at the same time, due to the dual curing characteristics of ultraviolet light and heating, the screen printing method is suitable for the full fit of the LED screen, the backlight module and The opaque area in the cover plate can be cured quickly by heating to 70°C, which is conducive to improving production efficiency.

Preparation method of transparent silicone gel that can be cured by ultraviolet light and heating: the above composition is mixed in a stainless steel, enamel or glass container according to the proportion, and then filtered and filled in a packaging container of a specified specification. The glue 3 after scraping is shown in Figure 1. Part of the glue enters between the screen frame and the surface of the product to be printed. First, the ultraviolet radiation is used to cure the area that can be irradiated by ultraviolet light, and then heated and cured, and the ultraviolet radiation cannot be reached. The area can be cured.

The printing process can be: opening a special screen frame corresponding to the product, different areas to be glued are different, so different screen frames will be opened, and the vacuum suction under the platform of the printing machine ensures that the glue product is flat, and the CCD alignment guarantees the cover. Corresponding to the position of the screen (make the opening of the screen frame and the ink opening of the cover just centered), when the screen is pressed down and fits to the product, the glue is filled through the middle of the left and right scrapers. Each time) The glue must be selected with a viscosity of 40,000 to 50,000. After the squeegee is completed, the product is transferred to the laminating machine through the mechanical arm. During the transfer process, the product is uniformly triggered by UV light and then heated and cured, pre-cured After the product is bonded by a vacuum bonding machine. The product is defoamed and cleaned after lamination.

Example 2: A printing process for a full-fit method

A printing process for a full lamination method includes a screen frame 4 having a bottom frame 2 for bonding to the surface of the product 1 to be printed with glue, and the inner side of the bottom frame is enclosed A glue application area 5 is formed. The surface of the glue product to be printed has a glue application area 6. The shape of the glue application area is a shape that simultaneously shrinks the glue application area. The sides of the glue application area of the surface of the product for printing glue are 1.3 mm apart, and the viscosity of the glue is 40000-50000 centipoise; when printing the glue, press the product to be printed with the frame of the frame and press the glue Fill the glued area of the screen frame, then scrape the glue with a scraper, part of the glue enters between the screen frame and the surface of the product to be printed with glue, and finally pre-cures.

Wherein, both the component A and the component B are (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 end-capped linear structure polysiloxane, and the viscosity of the component A is 50000 centipoise. The viscosity of the component B is 300 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is in accordance with the general formula ( 1) Compound:

Among them, R ₁ , R ₂ and R ₃ are all hydrogen groups, m=20 and n=1.

A preferred embodiment is: the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 300 ppm; the amount of platinum metal is 2 ppm of the total amount of the raw material formulation.

A preferred embodiment is that the inhibitor is 1-ethynylcyclohexanol and tetravinylcyclotetrasiloxane.

A preferred embodiment is that the component C is MQ silicone resin.

A preferred embodiment is that the MQ silicone resin is MQ vinyl polysiloxane, and the molar ratio of M units to Q units is 0.75.

Among them, R4 and R5 are vinyl groups, and x is equal to 1000.

Among them, R4 and R5 are vinyl groups, x=50.

A preferred embodiment is that the adhesion promoter is γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane are formed according to 8:1:1 mixture.

Example 3: A printing process for a full-fit method

A printing process for a full lamination method includes a screen frame 4 having a bottom frame 2 for bonding to the surface of the product 1 to be printed with glue, and the inner side of the bottom frame is enclosed A glue application area 5 is formed. The surface of the glue product to be printed has a glue application area 6. The shape of the glue application area is a shape that simultaneously shrinks the glue application area. The sides of the glue application area of the surface of the product for printing glue are 1.7 mm apart, and the viscosity of the glue is 40000-50000 centipoise; when printing the glue, press the product to be printed with the frame of the frame and press the glue Fill the glued area of the screen frame, then scrape the glue with a scraper, part of the glue enters between the screen frame and the surface of the product to be printed with glue, and finally pre-cures.

Wherein, both the component A and the component B are (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 end-capped linear structure polysiloxane, and the viscosity of the component A is 150,000 centipoise, so The viscosity of the component B is 10000 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is in accordance with the general formula ( 1) Compound:

Among them, R ₁ , R ₂ and R ₃ are all hydrogen groups, m=100 and n=10.

A preferred embodiment is: the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 5000 ppm; the amount of platinum metal is 20 ppm of the total amount of the raw material formulation.

A preferred embodiment is: the inhibitor is a mixture of 3-methyl-1-butyn-3-ol, 1-ethynylcyclohexanol and tetravinylcyclotetrasiloxane in a mass ratio of 1:1 .

A preferred embodiment is: the component C is a mixture of MDT phenyl silicone resin and MQ silicone resin in a mass ratio of 1:1.

A preferred embodiment is that the MQ silicone resin is MQ vinyl polysiloxane, and the molar ratio of M units and Q units is 1.0.

Among them, R4 and R5 are vinyl groups, and x is equal to 2000.

Among them, R4 and R5 are vinyl groups, x=50-2000.

A preferred embodiment is that the adhesion promoter is γ-methacryloxypropyltrimethoxysilane.

Example 4: A printing process for a full lamination method

A printing process for a full lamination method includes a screen frame 4 having a bottom frame 2 for bonding to the surface of the product 1 to be printed with glue, and the inner side of the bottom frame is enclosed A glue application area 5 is formed. The surface of the glue product to be printed has a glue application area 6. The shape of the glue application area is a shape that simultaneously shrinks the glue application area. The corresponding sides of the glue application area of the surface of the product for printing glue are 1.6 mm apart, and the viscosity of the glue is 40,000-50000 centipoise; when printing the glue, press the product to be printed with the frame of the frame and press the glue Fill the glued area of the screen frame, then scrape the glue with a scraper, part of the glue enters between the screen frame and the surface of the product to be printed with glue, and finally pre-cures.

Wherein, both the component A and the component B are (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 end-capped linear structure polysiloxane, and the viscosity of the component A is 80000 centipoise. The viscosity of the component B is 1500 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is in accordance with the general formula ( 1) Compound:

Among them, R ₁ , R ₂ and R ₃ are all hydrogen groups, m=65 and n=4.

A preferred embodiment is: the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 3850 ppm; the amount of platinum metal is 13 ppm of the total amount of the raw material formulation.

A preferred embodiment is that the inhibitor is a mixture of 1-ethynylcyclohexanol and tetravinylcyclotetrasiloxane in a mass ratio of 1:4.

A preferred embodiment is: the component C is a mixture composed of vinyl-terminated polysiloxane, MDT phenyl silicone resin, and MT silicone resin in a mass ratio of 1:3:1.

Among them, R4 and R5 are vinyl, and x is equal to 1100.

Among them, R4 and R5 are vinyl groups, x=150.

A preferred embodiment is that the adhesion promoter is γ-glycidyloxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane according to 1:3 The mass ratio constitutes the mixture.

Example 5: A printing process for a full-fit method

A printing process for a full lamination method includes a screen frame 4 having a bottom frame 2 for bonding to the surface of the product 1 to be printed with glue, and the inner side of the bottom frame is enclosed A glue application area 5 is formed. The surface of the glue product to be printed has a glue application area 6. The shape of the glue application area is a shape that simultaneously shrinks the glue application area. The sides of the glue application area of the surface of the product for printing glue are 1.2 mm apart, and the viscosity of the glue is 40000-50000 centipoise; when printing the glue, press the product to be printed with the frame of the frame and press the glue Fill the glued area of the screen frame, then scrape the glue with a scraper, part of the glue enters between the screen frame and the surface of the product to be printed with glue, and finally pre-cures.

Wherein, both the component A and the component B are (CH ₃ ) ₂ (CH ₂ =CH) SiO _1/2 end-capped linear structure polysiloxane, and the viscosity of the component A is 130,000 centipoise. The viscosity of the component B is 1000 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is in accordance with the general formula ( 1) Compound:

Among them, R ₁ , R ₂ and R ₃ are all hydrogen groups, m=80 and n=15.

A preferred embodiment is: the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 3500 ppm; the amount of platinum metal is 15 ppm of the total amount of the raw material formulation.

A preferred embodiment is that the inhibitor is 1-ethynylcyclohexanol.

A preferred embodiment is that the component C is MDT phenyl silicone resin.

Among them, R4 and R5 are vinyl groups, and x is equal to 2100.

Among them, R4 and R5 are vinyl groups, x=800.

The above-mentioned embodiments only exemplarily illustrate the principle and efficacy of the present invention, and are not intended to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims

A printing process for a full lamination method, characterized in that it includes a screen frame with a bottom frame for bonding to the surface of the product to be printed with glue, and an inner edge of the bottom frame Combined to form a glue area, the surface of the product to be printed with glue has an area to be glued, the shape of the glue area is the shape of the area to be glued down simultaneously, and the inner side of the bottom frame is to be printed The corresponding sides of the glued area of the surface of the glue product are 1.3-1.7mm apart, and the viscosity of the glue is 40000-50000 centipoise; Glue is applied to the glued area of the screen frame, and then the glue is scraped with a spatula. Part of the glue enters between the screen frame and the surface of the product to be printed with glue, and is finally pre-cured.
The printing process for a full lamination method according to claim 1, characterized in that the glue is a transparent silicone gel that can be double-cured by ultraviolet light and heating, and its raw material formulation includes the following parts by weight of raw materials:

Wherein, both the component A and the component B are (CH 3 ) 2 (CH 2 =CH) SiO 1/2 terminated linear structure polysiloxane, and the viscosity of the component A is 50000-150000 centipoise , The viscosity of the component B is 300-10000 centipoise; the component C is a vinyl polysiloxane with a branched structure, the component D is an adhesion promoter, and the component E is Compounds conforming to general formula (1):

Among them, R 1 , R 2 and R 3 are all hydrogen groups, 100≥m≥20, n≥1.
The printing process for the full lamination method according to claim 2, characterized in that the catalyst is a platinum metal complex, and the mass concentration of platinum metal in the platinum metal complex is 3000-5000ppm; The amount of platinum metal is 2-20ppm of the total blended amount of raw material formula.
The printing process for the full lamination method according to claim 2, wherein the inhibitors are 3-methyl-1-butyn-3-ol, 1-ethynylcyclohexanol and tetravinyl At least one of cyclotetrasiloxane.
The printing process for the full lamination method according to claim 2, characterized in that the component C is a vinyl-terminated polysiloxane, MDT phenyl silicone resin, MT silicone resin and MQ silicone resin At least one.
The printing process for the full lamination method according to claim 5, wherein the MQ silicone resin is MQ vinyl polysiloxane, and the molar ratio of the M unit and the Q unit is 0.75-1.0.
The printing process for the full lamination method according to claim 2, wherein the component A is a compound that meets the general formula (2):

Among them, R4 and R5 are vinyl groups, and x is greater than or equal to 1000.
The printing process for the full lamination method according to claim 2, wherein the component B is a compound that meets the general formula (2):

Among them, R4 and R5 are vinyl groups, x=50-2000.
The printing process for the full lamination method according to claim 2, wherein the adhesion promoter is γ-glycidyl ether oxypropyl trimethoxysilane, 2-(3,4-epoxy At least one of cyclohexane) ethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane.