Method for manufacturing three-dimensional package heat dissipation structure of rigid-flexible joint board

Abstract

The invention discloses a method for manufacturing a three-dimensional package heat dissipation structure of a rigid-flexible joint board. The method comprises the steps that a flexible substrate is manufactured; a bottom substrate and two rigid substrates are pressed on the flexible substrate; cavities are formed in the two rigid substrates in a dug mode respectively; two copper substrates fixedly adhere to the back surfaces of the two rigid substrates respectively; a bottom chip is welded to the bottom substrate, two top chips are welded to or adhere to the two copper substrates which are exposed because the cavities are formed in the rigid substrates in the dug mode, and the two top chips are bonded to the rigid substrates; the flexible substrate is bent, the two rigid substrates on two sides of the flexible substrate are arranged above the bottom chip of the bottom substrate, and filling of plastic package material is conducted to achieve fixing and forming; solder paste is welded to a bonding pad on the back surface of the bottom substrate in a brushed mode, a BGA ball is implanted in a steel net, backflow is conducted, and a package body is formed; the back surface of the bottom substrate is fixed on a PCB, and radiators are arranged on the two copper substrates. By means of the method, the number of heat dissipation routes of the package body is increased, and heat can be dissipated more effectively.

Description

technical field [0001] The invention relates to the technical field of microelectronic three-dimensional system-level packaging, in particular to a method for manufacturing a three-dimensional packaging heat dissipation structure of a rigid-flexible board. Background technique [0002] 202 is the lower chip; 204 is the upper chip; 206 is the flexible substrate; 208 is the inner surface of the flexible substrate; 212 is the lower chip pin; 214 is the upper chip pin; 216 is the bottom filling glue; 222 is the BGA ball array; 224 226 is the outer surface of the flexible substrate; 232 is the front of the lower chip; 234 is the back of the upper chip; 236 is the patch adhesive; 238 is the PCB board. [0003] The three-dimensional stacked structure is firstly mounted on a plane, and two chips 202 and 204 are soldered to both ends of a flexible substrate 206, and an underfill glue 216 is filled between the chips and the flexible substrate; Thermally conductive patch adhesive 236;...

AI Technical Summary

Problems solved by technology

[0004] The disadvantage of this three-dimensional stack structure is that the upper chip 204 has a big problem in terms of heat dissipation, and most of the heat generated by the upper chip 204 needs to be sequentially passed through the heat-conducting adhesive 236, the lower chip 202, the underfill adhesive 216, the flexible substrate 206, BGA balls 224 and PCB 238 are dissipated, and the heat is not easily dissipated, which eventually leads to an increase in the junction temperature of the upper chip 204 and affects the lifespan

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