Epoxy plastic cement and preparing method thereof

Abstract

The invention refers to a kind of new epoxy plastic sealed materials for integrated circuit sealing and the manufacturing method. The materials include liquid crystal epoxy resin 100 shares, 0-15 shares of ortho-aminotoluene phenolic aldehyde epoxy resin, 30-200 shares of firming agent, 700-1100 shares of inorganic fillers, 0.1-0.5 shares of firming accelerator. The method mixes the ingredients evenly, then the materials are melted and mixed through rubber mixing machine or double screw stem extruder under 90-220deg.C, and cooled to solid piece material, finally the method crushes the piece into powder, and presses and forms them under 60-90deg.C, 0.3-1MPa. The invention has high rigidity and flexibility, low heat expansion parameter and humidity absorption rate, high heat resistance.

Description

technical field [0001] The invention relates to a novel epoxy plastic sealing compound for integrated circuit packaging and a preparation method thereof. technical background [0002] Epoxy molding compound is a packaging material used in integrated circuits. It is composed of epoxy resin, curing agent, inorganic filler, curing accelerator, coupling agent, release agent, flame retardant, colorant and other components. During the packaging and molding process of integrated circuits, the epoxy resin and curing agent are cured and cross-linked under the action of heat, and the integrated circuit chip is embedded in it by injection molding to become an integrated circuit encapsulated by epoxy molding compound. [0003] At present, the epoxy molding compound uses o-cresol novolac epoxy resin, which has the following three disadvantages in performance: 1. The epoxy molding compound is not an airtight material, and the water vapor on the surface of the integrated circuit can pass t...

AI Technical Summary

Problems solved by technology

[0003] At present, the epoxy molding compound uses o-cresol novolac epoxy resin, which has the following three disadvantages in performance: 1. The epoxy molding compound is not an airtight material, and the water vapor on the surface of the integrated circuit can pass through the epoxy molding compound to reach the chip, causing the chip Corrosion; second, during thermal curing, because the thermal expansion coefficient of the epoxy molding compound is greater than that of chips, pins and other materials, thermal stress will be generated inside the integrated circuit, which will cause damage to the integrated circuit; third, during the surface mounting process, dip soldering The surface temperature of the integrated circuit in the reflow soldering process is as high as 215-260°C. If the integrated circuit is in a state of moisture absorption, the high temperature will vaporize the moisture inside the integrated circuit, and when the generated vapor pressure is higher than the strength of the epoxy molding compound, it will cause the internal peeling of the integrated circuit or The whole piece is cracked

The above problems can be improved by increasing the content of inorganic fillers, but if the amount of inorganic fillers is too much, the melt viscosity of the epoxy molding compound will increase, which will affect the processing and formability, making it difficult to adapt to small appearance, high density (multi-layer, multi-pin) , fine pitch) sealed structure

The above problems can also introduce hydrophobic groups such as silane and fluorine in the resin structure to improve its hygroscopic performance, but it will be accompanied by problems such as a decrease in strength, modulus and heat distortion temperature or a decrease in reactivity.

Therefore, it is currently impossible for the traditional novolac epoxy system to maintain low moisture absorption, resistance to dipping soldering, and reflow soldering resistance, and to have good fluidity and processability.