Semiconductor Terminal Structure for Reliable Ultrasonic Bonding
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Solution Overview
Problem
Existing semiconductor devices face issues with bonding failures between terminals and circuit board wirings due to partial contact during ultrasonic bonding, leading to reduced manufacturing yield and potential stress-induced distortions.
Innovation Solution
The semiconductor device incorporates a signal terminal with a recessed heel portion and a wedge-shaped slit in the resin layer, allowing for improved spring property and increased movable range, enabling secure ultrasonic bonding without partial contact and reducing stress-induced distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the terminal is made rigid to maintain bonding precision, then manufacturing precision is improved, but the terminal becomes susceptible to stress-induced distortions and bonding failures
Solution Approach 1:
The terminal is designed with a recessed heel portion that enables dynamic movement and flexibility during the bonding process. This recessed structure allows the terminal to adapt to positioning variations and stress changes, transforming a static rigid structure into a dynamic one that can absorb stresses while maintaining bonding precision.
Solution Approach 2:
The recessed heel portion acts as a pre-designed stress absorption zone that cushions against bonding failures before they occur. By anticipating stress concentrations at the heel portion, the design preemptively creates a recessed structure that prevents stress-induced distortions and bonding failures during the bonding process.
2Ease of manufacture
If the terminal structure is simplified to ease manufacturing, then ease of manufacture is improved, but bonding failures occur due to partial contact during ultrasonic bonding
Solution Approach 1:
The terminal is segmented into distinct portions: a heel portion with a recessed structure and a bonding portion. This segmentation allows each portion to serve its specific function - the heel portion absorbs stress and prevents partial contact, while the bonding portion ensures precise ultrasonic bonding. The segmentation is achieved through a straightforward recessed structure that does not significantly complicate manufacturing.
3Reliability
If the terminal is designed with high flexibility to prevent stress-induced distortions, then reliability is improved, but manufacturing precision during ultrasonic bonding deteriorates
Solution Approach 1:
Different portions of the terminal have different mechanical properties: the heel portion has higher flexibility due to the recessed structure to prevent stress-induced distortions, while the bonding portion maintains sufficient rigidity for precise ultrasonic bonding. This local differentiation of mechanical properties allows the terminal to simultaneously achieve reliability and manufacturing precision in different critical areas.
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 effectively suppresses bonding failures and stress-induced distortions, enhancing manufacturing yield and reliability of the semiconductor device.
Implementation Method 1
bonding failures between terminals and circuit board wirings due to partial contact during ultrasonic bonding
Data Source
AI summary
According to one embodiment, a semiconductor device includes: a substrate; a case provided on the substrate and including a resin layer and a terminal; and a circuit board provided on the substrate and including a semiconductor chip and a wiring electrically connected to the semiconductor chip and the terminal, wherein the terminal includes a first portion extending from the resin layer toward the circuit board, a second portion bonded to the wiring, and a third portion between the first portion and the second portion, and the third portion is recessed toward an opposite side of a side of the substrate from the second portion.