Positioning method for semiconductor chip suspending arm encapsulation

Abstract

A method of positioning a semiconductor chip cantilever encapsulation utilizes the pressure of an upper mould and a bottom mould which are matching to hold the pin or a lead frame edge and to keep a bare chip component is in cantilever support state in the mould cavity, as for the bare chip component with unilateral design pin, wherein, the positioning matching of the pin or the lead frame edge and the mould is utilized to position the bare chip component on X and Y directions corresponding with the mould cavity. The invention is characterized in the position on Z direction that: a positioning pin controlling the distance is arranged on the Z direction as for the bear chip or the lead frame in the upper and the bottom mould cavities, meanwhile, a guide inclined plane is arranged on the suspended lead frame and inclines toward one side of the positioning pin; an injection inlet of the encapsulation material points to the guide inclined plane; a lateral component is generated on the guide inclined plane when the encapsulation material in molten state is injected via the pressure at the injection inlet to push the bear chip component toward the end surface of the positioning pin on the Z direction, in order to realize Z direction position. The invention has the advantages of simplicity, reliability, low cost, smart conception and solves the problem of the Z direction position of the bear chip component by the cantilever support in the mould cavity.

Description

technical field [0001] The invention relates to the technical field of packaging of semiconductor devices, in particular to a positioning method for cantilever packaging of semiconductor chips. Background technique [0002] The packaging of semiconductor electronic components not only plays the role of connecting the internal semiconductor chip with the external electrical components, but also plays the role of mechanical protection and environmental sealing. Therefore, the quality of packaging is closely related to the overall performance of semiconductor devices. [0003] There are various packaging methods for semiconductor devices, among which there is a packaging method suitable for ordinary semiconductor devices, that is, injection molding. This method usually uses epoxy resin as the packaging material, and forms a cavity through pressure clamping of the upper and lower molds, while the bare chip component is positioned in the center of the cavity, and then pressure-i...

AI Technical Summary

Problems solved by technology

It is conceivable that if the bare chip assembly has front-to-back or left-right bidirectional pins, it is easy for the mold to press the pins from both ends to position the bare chip in the X, Y, and Z directions of the cavity; if a bare chip assembly has only one The positioning of the side unidirectional pins in the cavity will be in a cantilever state. In this state, the positioning of the bare chip component relative to the cavity space in the X and Y directions can be controlled by the cooperation of the pins and the mold, but the Z direction The positioning of the arm becomes difficult to control as the arm length increases

Especially for thin or flat semiconductor devices, not only the positioning in the Z direction is very necessary but also the control is very difficult

Because, if the position of a bare chip component in the Z direction in the cavity cannot be fixed, the distance from the chip to the surface of the body in the Z direction cannot be controlled. If the distance from the surface is too close, the insulation and voltage resistance of the device will be poor, which will directly affect the product quality. and pass rate

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