High-light-dimension-rate solid crystal glue as well as preparation method and application thereof

Abstract

The invention provides high-light-dimension-rate solid crystal glue as well as a preparation method and application of the high-light-dimension-rate solid crystal glue. The high-light-dimension-rate solid crystal glue is prepared from aliphatic epoxy resin, organic silicon modified epoxy resin, an anti-precipitating agent, a coupling agent, an antioxidant and a curing agent, the aliphatic epoxy resin and the organic silicon modified epoxy resin with special structures are used as main components, and the antioxidant, the anti-precipitating agent, the coupling agent and the curing agent are matched, so that the high-light-dimension-rate solid crystal glue is prepared; according to the present invention, the solid crystal glue has characteristics of simple preparation process and low cost, the performance optimization of the solid crystal glue is achieved, the problems that the existing solid crystal glue cannot meet the bonding requirement of the small-area chip and the yellowing resistance and the aging resistance are poor are solved, and the solid crystal glue can be widely used in the fields of the small-area chip, the RGB blue lamp chip and the like.

Description

[Technical field] The invention belongs to the technical field of adhesives, and in particular relates to a high-optical-ratio die-bonding adhesive for packaging, and a preparation method and application thereof. [Background technology] Die-bonding adhesive is an adhesive used to fix chips or other components to the specified area of ​​the substrate. It is a core component of LED packaging. Its main function is to provide a basis for subsequent wire bonding to ensure the adhesion and stability between the chip and the substrate. Among them, epoxy die-bonding adhesive and silicone die-bonding adhesive are usually used for chips without conductive requirements.

[0003] However, although the existing organic silicon die-cement adhesive has good thermal stability, UV resistance and aging resistance, its adhesion is poor and cannot meet the requirements of areas less than 40mil. 2 The existing epoxy die-bonding adhesive can meet the bonding needs of small-area chips, but its yellowing resistance and aging resistance are poor. [Summary of the invention] The purpose of the present invention is to provide a high-optical-rate die-bonding adhesive to solve the problem that the existing die-bonding adhesive cannot meet the bonding requirements of small-area chips and has poor yellowing resistance and aging resistance.

[0005] The present invention is achieved by the following technical solutions: A high-optical-ratio die-bonding adhesive, composed of the following components in parts by weight: Aliphatic epoxy resin: 55-75 parts; Silicone modified epoxy resin: 15-25 parts; Anti-precipitation agent: 2-4 parts; Coupling agent: 0.5-3 parts; Antioxidant: 0.1-0.5 parts; Curing agent: 0.5-1.2 parts.

[0006] Preferably, the structure of the aliphatic epoxy resin also contains at least one oxygen-containing group. The aliphatic epoxy resin is used as the main film-forming substance of the solid crystal adhesive to provide basic bonding performance and mechanical strength. Among them, its structure also contains at least one oxygen-containing group, such as hydroxyl, ether bond, carbonyl, etc., which helps to improve the compatibility and reactivity of the aliphatic epoxy resin with other components such as silicone-modified epoxy resin and antioxidant, thereby achieving performance optimization of the solid crystal adhesive.

[0007] More preferably, the aliphatic epoxy resin may be an alicyclic epoxy resin, which has good heat resistance, chemical stability and low hygroscopicity.

[0008] Preferably, the organosilicon-modified epoxy resin is any one of octacyclohexylethyl cyclotetrasiloxane and octacyclohexylethyl caged polysilsesquioxane. The organosilicon-modified epoxy resin has a cage structure, which can give the solid crystal adhesive good optical properties, and help improve the optical clarity and light transmittance of the solid crystal adhesive. Its silicon-oxygen bond can react with the oxygen-containing group of the aliphatic epoxy resin to form a stable chemical bond, which can further improve the bonding strength, heat resistance and weather resistance of the solid crystal adhesive.

[0009] Preferably, the anti-precipitation agent is fumed silica. Fumed silica has low density, large specific surface area, and excellent thickening thixotropy, and can be effectively dispersed in the system and form a specific network structure in the system, thereby increasing the viscosity and thixotropy of the system, thereby preventing the solid crystal adhesive from precipitating during storage or use.

[0010] Preferably, the coupling agent is any one of acrylic acid and epoxy group. The coupling agent has an inorganic-philic group and an organic-philic group, which can improve the bonding strength of the die-bonding adhesive by improving the interface performance.

[0011] Preferably, the antioxidant is a mixture of phenols and phosphates. The combined use of phenolic antioxidants and phosphate antioxidants can improve the antioxidant properties of the solid crystal glue. Phenolic antioxidants, as the main oxidant, can capture free radicals so that they no longer participate in the oxidation cycle, while phosphate antioxidants, as auxiliary oxidants, can decompose hydroperoxides to make them harmless products. The synergistic effect of the two can more effectively prevent the oxidative degradation of epoxy resins, thereby extending their service life. In addition, the antioxidant can form chemical bonds with the oxygen-containing groups of aliphatic epoxy resins, improve the weather resistance of the solid crystal glue, and keep its performance stable under ultraviolet rays and aging environments.

[0012] Preferably, the curing agent is any one of sulfonium hexafluoroantimonate and quaternary ammonium hexafluoroantimonate. Cationic hexafluoroantimonate is used as a curing agent, which has high thermal stability, high reactivity and low volatility, and can promote the curing reaction of aliphatic epoxy resin and silicone-modified epoxy resin to form a stable three-dimensional network structure, thereby improving the mechanical strength and heat resistance of the solid crystal adhesive.

[0013] The present invention also provides a method for preparing the high-optical-density die-bonding adhesive. According to the weight ratio, aliphatic epoxy resin, silicone-modified epoxy resin, anti-precipitation agent, coupling agent, antioxidant and curing agent are sequentially added into a dynamic mixer and stirred under certain temperature and stirring speed conditions to obtain the high-optical-density die-bonding adhesive.

[0014] Preferably, the temperature is 20-30° C., the stirring speed is 30 r / min for revolution and 25 r / min for rotation, and the stirring time is 60-90 min.

[0015] The present invention also provides an application of the high-light-density die-bonding adhesive in RGB chip packaging.

[0016] The beneficial effects of the present invention are as follows: The present invention provides a high-optical-dimension bonding adhesive. First, an aliphatic epoxy resin containing oxygen-containing groups in its structure is used as the main film-forming material of the bonding adhesive to provide basic bonding performance and mechanical strength, while improving the compatibility and reactivity with other components, thereby achieving performance optimization of the bonding adhesive. Second, an organosilicon-modified epoxy resin with a special structure is used in combination with an aliphatic epoxy resin to give the bonding adhesive good optical properties, improve the optical clarity and light transmittance of the bonding adhesive, and its silicon-oxygen bond can form a stable chemical bond with the oxygen-containing groups of the aliphatic epoxy resin, which can further improve the bonding strength, heat resistance and weather resistance of the bonding adhesive. Third, phenolic and phosphate antioxidants are used in combination with aliphatic epoxy resins to improve the oxidation resistance and weather resistance of the bonding adhesive. Finally, with the cooperation of an anti-precipitant, a coupling agent and a curing agent, a high-optical-dimension bonding adhesive is obtained, thereby solving the problem that the existing bonding adhesive cannot meet the bonding requirements of small-area chips, and has poor yellowing resistance and aging resistance.

[0017] The present invention also provides a method for preparing the high-optical-ratio crystal-bonding adhesive, which is simple to operate and can obtain the high-optical-ratio crystal-bonding adhesive without complicated pre-treatment.

[0018] The present invention also provides an application of the high-optical-dimension die-bonding adhesive in RGB chip packaging. Since the blue and green light chips in the RGB chip are relatively small in size, and the blue light chip has a shorter wavelength, the energy emitted is relatively high, and the destructive ability to the material structure is relatively strong, resulting in faster aging of the die-bonding adhesive bonding the blue light chip, which in turn affects the rapid attenuation of the brightness of the blue light chip. The high-optical-dimension die-bonding adhesive of the present invention has high optical dimension and good adhesion, which can effectively solve the problem of rapid brightness attenuation of the blue light chip during the lighting process, improve the light efficiency of the RGB chip, and reduce the aging of the chip. [Specific implementation method] The specific technical scheme of the present invention is described below in conjunction with Examples 1-3: Example 1 Prepare the components by weight according to Table 1, add aliphatic epoxy resin, silicone-modified epoxy resin, anti-precipitation agent, coupling agent, antioxidant and curing agent into a dynamic mixer in sequence, stir at 25°C at a speed of revolution of 30 r / min and rotation of 25 r / min, stir for 60 minutes, and obtain a high-optical-density die-cast adhesive.

[0020] Example 2 Prepare the components by weight according to Table 1, add aliphatic epoxy resin, silicone-modified epoxy resin, anti-precipitation agent, coupling agent, antioxidant and curing agent into a dynamic mixer in sequence, stir at 25°C at a speed of revolution of 30 r / min and rotation of 25 r / min, stir for 60 minutes, and obtain a high-optical-density die-cast adhesive.

[0021] Example 3 Prepare the components by weight according to Table 1, add aliphatic epoxy resin, silicone-modified epoxy resin, anti-precipitation agent, coupling agent, antioxidant and curing agent into a dynamic mixer in sequence, stir at 22°C at a speed of revolution of 30 r / min and rotation of 25 r / min, stir for 90 minutes, and obtain a high-optical-density die-cast adhesive.

[0022] Comparative Example 1 Prepare the components by weight according to Table 1, add aliphatic epoxy resin, anti-precipitation agent, coupling agent, antioxidant and curing agent into a dynamic mixer in sequence, stir at 25°C at a speed of 30 r / min for revolution and 25 r / min for rotation, stir for 60 minutes to obtain a solid crystal adhesive.

[0023] Comparative Example 2 Prepare the components by weight according to Table 1, add aliphatic epoxy resin, silicone-modified epoxy resin, anti-precipitation agent, coupling agent and curing agent into a dynamic mixer in sequence, stir at 25°C at a speed of 30 r / min for revolution and 25 r / min for rotation, stir for 60 minutes to obtain a solid crystal adhesive.

[0024] Comparative Example 3 is a commercially available epoxy die-bonding adhesive.

[0025] Comparative Example 4 is a commercially available organic silicon die-bonding adhesive.

[0026] Table 1 Composition ratio of Examples 1-3 and Comparative Examples 1-2

[0027] The above-mentioned embodiments 1-3 and comparative examples 1-4 were subjected to performance tests. The test conditions were as follows and the test data are shown in Tables 2-3.

[0028] Light intensity test: Use die-bonding glue to bond the die, make lamp beads by welding wires and sealing glue, stick the lamp beads on the aging board, and put them in an 85℃ high-temperature oven for aging test. During the test, test the light intensity of the lamp beads in different time periods, and calculate the light intensity, that is, the ratio of the light intensity in the corresponding time period to the initial light intensity.

[0029] Adhesion test: Use bonding glue to bond 5mil*8mil chips. After bonding, bake at 170℃ for 2.5h, and then use a push-pull test machine to test the adhesion of 10 identical chips. During the test, the heating table of the push-pull test machine is heated to 160℃.

[0030] Table 2 Optical Dimension Test of Examples 1-3 and Comparative Examples 1-4

[0031] Table 3 Adhesion test of Examples 1-3 and Comparative Examples 1-4

[0032] As shown in Table 2, compared with Comparative Example 1 without using silicone-modified epoxy resin, Comparative Example 2 without using antioxidant, and Comparative Example 3 of commercially available epoxy die-bonding adhesive, the high optical density of the die-bonding adhesive of Examples 1-3 has a higher optical density.

[0033] As shown in Table 3, compared with Comparative Example 4 of the commercially available organic silicon die-bonding adhesive, the high optical density die-bonding adhesive of Examples 1-3 has better adhesion.

[0034] As shown in Table 2 and Table 3, the commercial epoxy die-bonding adhesive of Comparative Example 3 has good bonding performance, but its optical fiber ratio is poor; the commercial silicone die-bonding adhesive of Comparative Example 4 has good optical fiber ratio, but its bonding performance is poor. The high optical fiber ratio die-bonding adhesives of Examples 1-3 have both high optical fiber ratio and can meet the bonding requirements of small-area chips.

[0035] The above examples are only used to further illustrate the technical content of the present invention, so that readers can understand it more easily, but they do not mean that the implementation of the present invention is limited to this. Any technical extension or re-creation made according to the present invention is protected by the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A high-light-ratio die-bonding adhesive, characterized in that: By weight, it is composed of the following components: Aliphatic epoxy resin: 55-75 parts; Silicone modified epoxy resin: 15-25 parts; Anti-precipitation agent: 2-4 parts; Coupling agent: 0.5-3 parts; Antioxidant: 0.1-0.5 parts; Curing agent: 0.5-1.2 parts.

2. The high optical density die-bonding adhesive according to claim 1, characterized in that: The aliphatic epoxy resin further comprises at least one oxygen-containing group in its structure.

3. The high optical density die-bonding adhesive according to claim 1, characterized in that: The organosilicon-modified epoxy resin is any one of octacyclohexylethyl cyclotetrasiloxane and octacyclohexylethyl caged polysilsesquioxane.

4. The high optical density die-bonding adhesive according to claim 1, characterized in that: The anti-precipitation agent is fumed silica.

5. The high optical density die-bonding adhesive according to claim 1, characterized in that: The coupling agent is any one of acrylic and epoxy.

6. The high optical density die-bonding adhesive according to claim 1, characterized in that: The antioxidant is a mixture of phenols and phosphates.

7. The high optical density die-bonding adhesive according to claim 1, characterized in that: The curing agent is any one of sulfonium hexafluoroantimonate and quaternary ammonium hexafluoroantimonate.

8. The method for preparing a high-optical-density die-bonding adhesive according to any one of claims 1 to 7, characterized in that: According to the weight ratio, aliphatic epoxy resin, silicone modified epoxy resin, anti-precipitation agent, coupling agent, antioxidant and curing agent are added into a dynamic mixer in sequence and stirred at a certain temperature and stirring speed to obtain a high-optical-ratio solid crystal adhesive.

9. The method for preparing a high-optical-ratio die-bonding adhesive according to claim 7, characterized in that: The temperature is 20-30° C., the stirring speed is 30 r / min for revolution and 25 r / min for rotation, and the stirring time is 60-90 min.

10. Application of the high-efficiency die-bonding adhesive as claimed in any one of claims 1 to 7 in RGB chip packaging.

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