Resin-Molded Semiconductor Device with Grooved Casing
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Solution Overview
Problem
Conventional semiconductor devices face challenges in providing high heat dissipation and insulation while maintaining a compact size due to the use of squeeze pins, which increase the size and stiffness of the die pad, requiring larger apparatuses for adhesion and potentially compromising adhesion quality between the die pad and resin sheet.
Innovation Solution
A semiconductor device and mold design where the resin supplied into the cavity forces the entire area of the die pad against the underlying resin sheet during molding, ensuring excellent adhesion and insulation, with a groove on the resin casing and a ridge in the mold structure to secure the die pad firmly to the resin sheet, reducing the need for squeeze pins and allowing for cost reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If squeeze pins are used to force the die pad against the resin sheet, then adhesion between the die pad and resin sheet is improved, but the device size and manufacturing apparatus size increase
Solution Approach 1:
The invention extracts and eliminates the squeeze pins from the molding apparatus. Instead of using mechanical squeeze pins to force the die pad against the resin sheet, the patent uses the resin material itself to provide the necessary pressing force during molding, thereby removing the need for additional squeezing mechanisms and reducing apparatus size.
Solution Approach 2:
The resin material serves a dual function: it acts as both the molding material and the pressing medium. The resin itself provides the force needed to adhere the die pad to the resin sheet, eliminating the need for separate squeezing mechanisms. This self-service approach simplifies the apparatus while maintaining adhesion quality.
2Reliability
If squeeze pins are used to force the die pad against the resin sheet, then adhesion between the die pad and resin sheet is improved, but the die pad thickness and stiffness increase
Solution Approach 1:
The invention removes the squeeze pins that were causing the die pad to thicken and stiffen. By using the resin material itself to provide pressing force during molding, the die pad maintains its original thin and flexible characteristics while still achieving strong adhesion to the resin sheet.
3Volume of stationary object
If the die pad is made thinner and more flexible, then device size is reduced, but adhesion between the die pad and resin sheet becomes difficult to ensure
Solution Approach 1:
The resin material provides self-service by simultaneously acting as the molding compound and the adhesion-promoting medium. During molding, the resin naturally flows and presses the thin, flexible die pad against the resin sheet, ensuring strong adhesion without requiring the die pad to be thick or stiff.
Solution Approach 2:
The invention changes the parameters of the molding process to accommodate thin, flexible die pads. By controlling the molding pressure and resin flow characteristics, the process ensures that even thin die pads achieve proper adhesion to the resin sheet without requiring mechanical squeeze pins.
4Reliability
If squeeze pins are used in the molding process, then adhesion is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The invention extracts and eliminates the squeeze pins and associated complex positioning mechanisms from the molding process. The simplified process uses only the resin material to provide pressing force, significantly reducing manufacturing complexity while maintaining adhesion quality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances heat dissipation capabilities, provides reliable adhesion between the die pad and resin sheet, and reduces the size and cost of the semiconductor device by eliminating the need for large apparatuses and squeeze pins, while maintaining high insulation quality.
Implementation Method 1
the resin supplied into the cavity forces an entire area of the die pad against the underlying resin sheet in a molding process
Implementation Method 2
the resin sheet being firmly adhered to the die pad... providing a capability to efficiently dissipate heat generated by the power chip
Data Source
AI summary
A semiconductor device includes a pair of power chips, an IC chip, a plurality of leads one of which having a die pad on which the power chips are mounted and another one having a die attach portion on which the IC chip is mounted, a resin sheet firmly adhered to one side of the die pad, and a resin casing made by molding operation to encapsulate the power chips, the IC chip and the resin sheet by a resin in such a manner that one surface of the resin sheet opposite the die pad is exposed to the exterior of the resin casing. The resin casing has a groove formed in one surface opposite the exposed surface of the resin sheet, the groove extending parallel to the resin sheet and perpendicular to a runner through which the resin was supplied in the molding operation.