Sealing cover balance filling packaging structure and process for sorted flip chips

Abstract

The invention discloses a sealing cover balance filling packaging structure and process for sorted flip chips. The structure comprises a substrate, a flip chip, silicon gaskets, and a metal cover. Themetal cover is welded on the substrate, and the flip chip is located in the metal cover. Filling glue is arranged between the flip chip and the substrate, and the silicon gaskets are arranged on theleft and right sides of the back surface of the flip chip. The upper sides and the lower sides of the silicon gaskets are bonded with the metal cover and the flip chip through heat conduction adhesivelayers. According to the scheme, the structure in which the upper and lower heat conduction interface adhesive layers and the left and right silicon gaskets are combined is adopted, the minimum heatdissipation contact area is guaranteed, left-right balance and no position offset during pasting of the metal cover are guaranteed, and sealing cover product packaging with excellent heat dissipationis achieved. The heat dissipation coefficient of the heat conduction interface adhesive is 3.4 W / Mk, and the heat dissipation coefficient of the silicon gaskets is 149 W / mK. Rapid transfer of heat from the thin sorted flip chip to the metal cover is realized, personalized pursuit of clients for packaging types is satisfied, and the process also has higher mass production operability.

Description

technical field [0001] The invention relates to a capping balanced filling packaging structure and technology for sorting flip chips, and belongs to the technical field of integrated circuit flip chip packaging. Background technique [0002] When the chip is flip-chip soldered on a substrate or other carrier board, it is generally necessary to embed an underfiller between the bumps of the chip, and the bottom of the metal cover (Lid cover) is strongly connected to the substrate by an adhesive. The substrate or other carrier is supported; the top of the cavity of the metal cover is connected to the back of the chip (non-electrical surface) through the interface heat dissipation material (TIM glue) to realize heat conduction, and then the ball is planted and cut into shape. [0003] However, when the thickness of the sorting flip chip is less than 500 μm, and the cavity depth of the conventional metal cover is higher than 800 μm, the thermal paste on the normal brush interface...

AI Technical Summary

Problems solved by technology

[0003] However, when the thickness of the sorting flip chip is less than 500 μm, and the cavity depth of the conventional metal cover is higher than 800 μm, the thermal paste on the normal brush interface cannot completely fill the minimum gap space of about 300 μm or even larger, and achieve efficient heat dissipation; thus only Plastic packaging (EMC) type FCBGA packaging can be used, which cannot meet the individual requirements of customers for the packaging form; especially on the premise that the metal cover shares the mold and the size is unified to ensure that the cost is minimized

Images