QFN package structure with anti-short circuit function

Abstract

The invention discloses a QFN package structure with anti-short circuit function, comprising a heat dissipation pad located in an epoxy insulator, a chip and a conductive pad, the chip is located on the heat dissipation pad, and the gap between the chip and the heat dissipation pad is There is a silver paste layer between them, and several conductive pads are arranged around the heat dissipation pad; the raw materials of the epoxy insulator include the following components by weight: 80~100 parts of epoxy resin, novolac resin, liquid nitrile rubber , diphenylmethane diisocyanate, diethyl pyrocarbonate, dibenzyl phosphate, silicon micropowder, γ-methacryloxypropyltrimethoxysilane, 5-fluoro-2-methoxyaniline, 2, 4,6‑tris(dimethylaminomethyl)phenol, release agent, flame retardant. The QFN encapsulation structure of the invention has good short-circuit prevention function, good overall mechanical properties, stable structure and high reliability.

Description

technical field [0001] The invention belongs to the technical field of leadless packaging, in particular to a QFN packaging structure with short-circuit prevention function. Background technique [0002] QFN packaging is widely used in PCB boards, and the application of QFN packaging has greatly promoted the development of electronic technology. The QFN package has excellent thermal performance, mainly because there is a large area of ​​heat dissipation soldering at the bottom of the package. In order to effectively conduct heat from the chip to the PCB, the bottom of the PCB must be designed with corresponding heat dissipation pads and heat dissipation vias. The pad provides a reliable soldering area, and the thermal via provides a heat dissipation path. [0003] The conventional QFN package design in the PCB usually has a large-area heat dissipation pad, which is usually grounded. Although this heat dissipation pad can play the role of chip heat dissipation, it is often t...

AI Technical Summary

Problems solved by technology

[0003] The conventional QFN package design in the PCB usually has a large-area heat dissipation pad, which is usually grounded. Although this heat dissipation pad can play the role of chip heat dissipation, it is often too large to Too much tin brushing during the (SMT) process will cause a short circuit between the large heat dissipation pad in the center of the QFN package and other small conductive pads

In addition, with the continuous development of integrated circuit packaging towards high density, high integration, and high speed, the packaging structure is also facing a series of reliability risks caused by chip heating.

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