Semiconductor Device Resist Protrusion Solder Thickness Control
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Solution Overview
Problem
Conventional semiconductor devices face issues with uniform solder thickness and semiconductor element inclination when joined by solder, leading to production time and cost inefficiencies, as well as inadequate heat dissipation and crack propagation.
Innovation Solution
A semiconductor device design featuring a resist with protrusions that overlap the semiconductor element, regulating its thickness and providing uniform solder distribution, thereby preventing inclination and enhancing heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If solder is provided directly below the semiconductor element to join metal pattern and semiconductor element, then bonding strength is achieved, but solder thickness becomes non-uniform causing semiconductor element inclination
Solution Approach 1:
A resist structure with protrusions is formed in advance at the solder application position. The protrusions pre-define the solder thickness by limiting the downward flow of solder, ensuring uniform solder thickness before the semiconductor element is bonded. This preliminary structural preparation prevents inclination while maintaining bonding strength.
2Manufacturing precision
If wire bond is provided in advance to ensure solder thickness, then solder thickness uniformity is improved, but production time and cost increase
Solution Approach 1:
The wire bond process is completely removed from the manufacturing flow. Instead of adding wire bonds to control solder thickness, the invention uses a resist structure with protrusions that directly limits solder flow. This extraction of the wire bond step eliminates the associated production time and cost while achieving the same solder thickness uniformity.
Solution Approach 2:
The resist material, which is inexpensive and temporary, is used to control solder thickness. The resist protrusions serve their purpose during solder application and can be removed afterward, replacing the more permanent and costly wire bond solution with a disposable, low-cost alternative that achieves the same thickness control function.
3Stability of the object's composition
If resist is provided to surround solder as disclosed in Japanese Patent Application Laid-Open No. 2006-49777, then solder containment is achieved, but semiconductor element inclination is not suppressed
Solution Approach 1:
Instead of a uniform resist structure surrounding the solder, protrusions are created at specific local positions within the resist. These localized protrusions directly contact and regulate the solder thickness at critical points, providing both containment and thickness control. The local quality enhancement at protrusion locations prevents semiconductor element inclination while maintaining overall solder containment.
Data Source
AI summary
A semiconductor device according to the present invention includes a resist provided so as to have an opening on a metal pattern, the resist having a protrusion part protruding into the opening, and the semiconductor device further includes a semiconductor element having an outside dimension smaller than an outside dimension of the opening excluding the protrusion, and solder provided inside the opening to join the metal pattern and the semiconductor element, wherein the protrusion part of the resist includes a plurality of protrusions that overlap with the semiconductor element in a plan view and regulate a thickness direction of the semiconductor element.