Semiconductor Package Adhesion Structure for Overflow and Air Ingress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor devices, adhesive overflow and air ingress due to misapplication or warping of the base plate lead to reliability issues, such as filler peeling and leakage, which are not effectively addressed by existing skirt structures.
Innovation Solution
The semiconductor device incorporates inclined surfaces on the base plate and case, with an adhesive region on these surfaces and a concave portion to manage adhesive overflow and air ingress, using high-viscosity adhesives and materials with high thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a skirt structure is provided to prevent adhesive overflow, then adhesive overflow is reduced, but the device complexity increases and external dimensions cannot be maintained
Solution Approach 1:
The base plate is segmented into multiple regions: a flat region for normal adhesion and an inclined region that slopes downward toward the case. This segmentation allows the adhesive to be contained on the inclined surface without requiring external skirt structures, thus preventing overflow while maintaining simple device geometry.
Solution Approach 2:
The solution transitions from a two-dimensional flat adhesion surface to a three-dimensional inclined surface. By creating a slope on the base plate, the adhesive is guided along the inclined dimension toward the case, preventing overflow without adding external structural complexity.
2Object-generated harmful factors
If adhesive application position is shifted inward to prevent overflow, then adhesive overflow is reduced, but air enters the gap and causes filler peeling
Solution Approach 1:
The inclined surface, which could potentially create gaps, is instead used to guide the adhesive flow. The slope directs the adhesive toward the case, and any excess adhesive is contained by the case's lower end, converting the potential harm of gap formation into a beneficial adhesive distribution mechanism that prevents both overflow and air ingress.
3Strength
If adhesive application position is shifted outward to ensure coverage, then adhesion is improved, but adhesive overflows beyond the case
Solution Approach 1:
Different regions of the base plate are given different properties: the flat region provides stable adhesive application, while the inclined region provides adhesive flow control. This local differentiation allows the adhesive to be applied generously for strong bonding while the inclined surface locally controls the adhesive flow to prevent overflow.
4Stability of the object's composition
If the base plate is warped in advance to correct reflow warp, then warpage is corrected, but gaps occur at adhered areas causing filler leakage
Solution Approach 1:
The inclined surface acts as a pre-prepared cushioning structure that anticipates adhesive overflow. By providing this slope before assembly, the system is prepared to handle variations in base plate warpage and adhesive application, preventing gaps and filler leakage without requiring precise pre-warping of the base plate.
Data Source
AI summary
A semiconductor device of an embodiment includes a circuit board, a base plate, a case, and a concave portion. The circuit board is equipped with semiconductor elements. The base plate supports the circuit board on a support surface. The case is adhered to the base plate at an adhesive region in a normal direction to the support surface. The case surrounds the circuit board. The base plate has a first inclined surface. The first inclined surface is inclined with respect to the support surface. The case has a second inclined surface. The second inclined surface is parallel to the first inclined surface and faces the first inclined surface in the normal direction. The adhesive region is provided on each of the first and second inclined surfaces. The concave portion opens to the outside between the base plate and the case. At least one of the first inclined surface and the second inclined surface is exposed in the concave portion.