CN100448909C - Photosensitive element packaging material composition and use method thereof - Google Patents

Abstract

The invention relates to a material composition for packaging, which comprises (1) epoxy resin and (2) a hardening agent, wherein the mixing ratio of the epoxy resin to the hardening agent is 0.7-1.1. The invention also relates to a method for encapsulating a photosensitive element on a substrate using the material composition.

Description

Photosensitive element encapsulating material composition and using method thereof

technical field

The invention relates to an encapsulating material composition and its application for encapsulating photosensitive elements.

Background technique

With the advent of the digital age, photosensitive elements have been widely used in various electronic products, especially image sensors, which have developed by leaps and bounds in recent years.

The general image sensor packaging method is to first make a frame (dam) around each module line with a molding compound on the substrate by transfer molding, and then adhere the image sensor chip with conductivity. The adhesive is fixed in the circuit and wire bonding is completed, and then a layer of adhesive is coated on the frame, and the glass sheet is covered and cured to complete the finished product, such as in the announcements of Taiwan Patent Nos. 459355, 478136, 503574 and 501244 The image sensor packaging structure and packaging method disclosed in the case.

In general manufacturing processes, the light-transmitting layer covering the image sensor chip is mostly glass, such as described in the above-mentioned patent announcement. The reason is that glass has low refractive index, high light transmittance and scratch resistance, but in The packaging process must be packaged in a single package, which consumes a lot of manpower and time, making it difficult to improve the yield rate and high manufacturing costs.

In addition, in China Taiwan Patent No. 489532, a stack structure of an image sensor is described. The molding method also uses molding compound and transfer molding method, but the light-transmitting layer is molded and covered with a transparent resin layer instead of using glass, however the patent does not teach, disclose or suggest the properties of the transparent resin or the effect on light.

Known epoxy resins with benzene ring structure, such as bisphenol A (bisphenol A), bisphenol F (bisphenol F) and bicyclic (nathalene), although they are transparent, their refractive index after hardening is high. 1.50, this is because when visible light passes through the benzene ring structure, the unsaturated bond (π bond) on the benzene ring will absorb light energy and cause π-π* interaction to change the refractive index and light transmittance of light. However, if the epoxy resin without benzene ring structure is used instead, although the refractive index can be effectively reduced, other properties such as high glass transition temperature and heat resistance cannot achieve glass characteristics.

The inventors of the present case have found through extensive research that material compositions with certain specific components are suitable as packaging materials, in particular, can be used as packaging materials for image sensors. After hardening, the material composition has the advantages of high glass transition temperature, low refractive index, high light transmittance, scratch resistance, etc., and can successfully replace glass as a light-transmitting layer. And the composition of the present invention is used for encapsulation on the substrate. After the composition is heated and hardened, the encapsulated substrate can be cut into a single module one by one, which is simpler and more feasible than the general use of glass for single encapsulation. Reduce costs and increase productivity and yield.

Contents of the invention

The object of the present invention is to provide an encapsulation material composition, which includes (1) epoxy resin and (2) hardener, wherein the mixing ratio of the epoxy resin to the hardener is 0.7˜1.1.

Another object of the present invention is to provide a method of using the above encapsulating material composition on a substrate to encapsulate a photosensitive element.

Implementation

The packaging material composition of the present invention comprises (a) epoxy resin and (b) hardener, wherein the mixing ratio of the epoxy resin relative to the hardener is 0.7-1.1, and preferably 0.85-1.0 .

The epoxy resin used in the present invention is not particularly limited, and the epoxy resin that can be used in the present invention can be bisphenol A type epoxy resin, bisphenol F type epoxy resin, aliphatic epoxy resin, alicyclic ring epoxy resins or mixtures of two or more such epoxy resins. Preferred epoxy resins are aliphatic epoxy resins, cycloaliphatic epoxy resins or mixtures thereof. Non-limiting examples of suitable epoxy resins include, for example, ERL-4221 and ERL-4229 from Dow Chemical; Holxy modifer 68 and Holxy modifer 107; and EPICLONEXA-7015, EXA-7120 and EPICLON 726D of Dainippon Ink.

Hardeners useful in the compositions of the present invention are known to those skilled in the art, non-limiting examples of which include, for example, anhydride compounds. Anhydride compounds that can be used in the present invention are such as but not limited to hexahydrophthalic anhydride (Hexahydrophthalic anhydride), methyl hexahydrophthalic anhydride (MHHPA), methyl-bicyclo[2,2,1]- Heptyl-2,3-dicarboxylic anhydride (Methyl-bicyclo[2,2,1]-heptene-2,3-dicarboxylic anhydride, referred to as NMA (Nadic Methyl Anhydride)), succinic anhydride (Succinic anhydride) or hexafluoro Hexafluoroisopropylidene-2,2-bisphthalic anhydride or a mixture thereof.

The packaging material composition of the present invention may optionally contain additives known to those skilled in the art, such additives may be accelerators, defoamers, antioxidants and the like.

Accelerators that can be used in the present invention are well known to those skilled in the art, a non-limiting example of which is 1,8-diazabicyclo[5,4,0]-undec-7-ene (1,8-diazabicyclo[5,4,0]-undec-7-ene, DBU) salts, quaternary ammonium salts and imidazolates. Quaternary ammonium salts useful as accelerators are well known to those skilled in the art, non-limiting examples of which may be benzyltributylammonium halide, benzyltrimethylammonium halide, benzyltrimethylammonium halide, Propylammonium halide, phenyltributylammonium halide, tetrabutylammonium halide, triphenylbenzylammonium halide, tetraethylammonium halide, and cetyltrimethylammonium halide.

The present invention also relates to a method of using the above-mentioned encapsulating material composition for encapsulating a photosensitive element, which includes applying the encapsulating material composition on a photosensitive element of a substrate. According to the present invention, a non-limiting example of a photosensitive element may be an image sensor, and a non-limiting example of a substrate may be a printed circuit board or a leadframe.

According to a specific embodiment of the present invention, the present invention provides an image sensor packaging material composition, which comprises: (1) an epoxy resin selected from an aliphatic epoxy resin, an alicyclic epoxy resin or a mixture thereof and ( 2) A hardener selected from acid anhydride compounds, wherein the mixing ratio of the epoxy resin to the hardener is 0.7-1.1, preferably 0.85-1.0.

The following examples will further illustrate the present invention, but not in order to limit the scope of the present invention, any modifications and changes that are achieved by those who are familiar with the technical field of the present invention without departing from the spirit of the present invention, all belong to the present invention scope.

Example

Prepare the formula shown in the following table 1 and prepare according to the following steps:

Table 1 Recipe

Mix the epoxy resin, hardener and accelerator in proportion, pour it into an aluminum dish, bake it at 120°C for one hour, and control the thickness of the test piece to about 1mm. The light transmittance in the range of 400-800nm in the visible light range was tested by an ultraviolet light absorption spectrometer, and the background was air. The results obtained are shown in Table 2 below.

The refractive index is to mix the epoxy resin, hardener and accelerator in proportion and then use a spin coater to coat a thin film of about 5m on the silicon wafer. After baking and hardening, use METRICON Model 2010 Prism Coupler to measure the refractive index , using a wavelength of 1320nm. The results obtained are shown in Table 2 below.

Mix the epoxy resin, hardener and accelerator in proportion, pour it into an aluminum dish, bake it at 120°C for one hour, and control the thickness of the test piece to about 1mm. The scratch resistance of the material was tested using a pencil hardness tester. In addition, the molded test piece was analyzed with a thermal mechanical analyzer (Thermal Mechanical Analyzer, PE DMA7.0) to measure the glass transition temperature. The results obtained are shown in Table 2 below.

Table 2: Test Results

Recipe one Recipe 2 Transmittance ＞90% ＞90% Refractive index 1.5342 1.4889 Glass transition temperature ℃ 125 153 Pencil hardness 2H 3H

From the results in Table 2, it can be seen that the material composition containing aliphatic epoxy resin or alicyclic epoxy resin and the mixing ratio of 0.7 to 1.1 with the hardener has good light transmittance, low refractive index, high glass Transition temperature and good scratch resistance properties.

Claims (4)

1. A material composition for encapsulating an image sensor, consisting of the following components: (1) epoxy resins selected from aliphatic epoxy resins, alicyclic epoxy resins, or mixtures thereof, (2) hardeners selected from acid anhydride compounds, and (3) selected from 1,8-diazabicyclo An accelerator for [5,4,0]-undec-7-ene salts, quaternary ammonium salts or mixtures thereof, wherein the mixing ratio of the epoxy resin to the hardener is 0.85-1.0. 2. The composition of claim 1, wherein the anhydride compound is selected from the group consisting of hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl-bicyclo[2,2,1]-heptyl-2, 3-Dicarboxylic anhydride, succinic anhydride, hexafluoroisopropyl-2,2-bisterephthalic anhydride and mixtures thereof. 3. A material composition for encapsulating an image sensor, consisting of the following components: (1) epoxy resins selected from aliphatic epoxy resins, cycloaliphatic epoxy resins or mixtures thereof, (2) hardeners selected from acid anhydride compounds, (3) selected from 1,8-diazabicyclo[ 5,4,0]-undec-7-ene salts, accelerators of quaternary ammonium salts or mixtures thereof, and (4) additives selected from defoamers, antioxidants and mixtures thereof, wherein the ring The mixing ratio of the oxygen resin to the curing agent is 0.85 to 1.0. 4. The composition of claim 3, wherein the anhydride compound is selected from the group consisting of hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl-bicyclo[2,2,1]-heptyl-2, 3-Dicarboxylic anhydride, succinic anhydride, hexafluoroisopropyl-2,2-bisterephthalic anhydride and mixtures thereof.