Conductive Post Recessed Portion for Semiconductor Molding Warping
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Solution Overview
Problem
The manufacturing yield of semiconductor devices is reduced due to substrate warping, which causes gaps between the insulating circuit substrate and the molding die, leading to thick resin burrs that are difficult to remove, resulting in assembly failures.
Innovation Solution
The semiconductor device incorporates conductive posts with recessed portions that deform under shear stress, reducing substrate warping and facilitating the removal of resin burrs during the molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive posts are used to support the wiring substrate to the insulating circuit substrate, then electrical interconnection is achieved, but substrate warping occurs causing gaps during molding
Solution Approach 1:
The conductive post is designed with a recessed portion at its outer peripheral surface, creating a localized structural feature. This recessed portion deforms under shear stress to absorb warping forces, while the main body of the conductive post maintains its structural integrity for electrical conduction. The local modification does not compromise the overall electrical interconnection function.
Solution Approach 2:
The conductive post's physical parameters are modified by introducing a recessed portion that changes the stress distribution characteristics. When shear stress occurs during molding, the recessed portion deforms plastically, changing the mechanical response of the conductive post from rigid to compliant, thereby absorbing warping energy while maintaining electrical connectivity.
2Ease of manufacture
If the substrate stack is molded in the cavity, then the resin sealing body is formed, but gaps between the insulating circuit substrate and molding die cause thick resin burrs
Solution Approach 1:
The recessed portion of the conductive post acts as a pre-designed stress absorption feature that cushions the substrate stack against warping forces during the molding process. By providing this compliant element beforehand, the substrate maintains better contact with the molding die wall, preventing gap formation and reducing resin burr formation at the critical interface.
3Productivity
If resin burrs are formed on the back surface of the insulating circuit substrate, then the molding is complete, but thick resin burrs are difficult to remove causing assembly failure
Solution Approach 1:
The recessed portion of the conductive post, which creates stress concentration points, inadvertently serves as a beneficial feature by controlling and limiting resin flow during molding. The deformation of the recessed portion creates a mechanical interlock that prevents excessive resin accumulation, converting what could be a defect (recessed structure) into a benefit (controlled resin flow and reduced burr formation).
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 improves the manufacturing yield by reducing resin burrs and preventing assembly failures, enhancing the productivity of semiconductor device production.
Implementation Method 1
The conductive post has a recessed portion recessed from an outer peripheral surface toward an inner side. The recessed portion deforms under shear stress.
Data Source
AI summary
A semiconductor device including: an insulating circuit substrate including a principal surface and a back surface; semiconductor chips each including an electrode on a principal surface and having a back surface on an opposite side to the principal surface, the back surface being fixed to the principal surface of the insulating circuit substrate; a wiring substrate facing the principal surface side of the insulating circuit substrate, separated from the semiconductor chip; a conductive post fixed to the electrode of the semiconductor chips and the wiring substrate; and a resin sealing body sealing the insulating circuit substrate, the semiconductor chips, the wiring substrate, and the conductive posts in such a manner as to expose the back surface of the insulating circuit substrate, wherein the semiconductor chips are respectively arranged on sides on which two short sides are located, and the conductive post has a recessed portion on its peripheral surface.