Patterned Solder Mask for Thermal Relief Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor package systems face challenges with thermal management due to increasing heat generation from transistors, leading to delamination issues between the die attach adhesive and thermal relief pads, which results in cracking of the encapsulant and system failure.
Innovation Solution
A semiconductor package system with thermal relief pads is developed, where a patterned solder mask is applied to partially cover the thermal relief pads, allowing the die attach adhesive to bond better to the mask areas over the pads, reducing air entrapment and improving bonding, and featuring a regular pattern such as a mesh or cross-hair design to enhance heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermal relief pads are fully exposed without mask, then heat dissipation is maximized, but delamination occurs between die attach adhesive and thermal relief pads
Solution Approach 1:
The solder mask is selectively applied to create different surface properties in different areas: the die attach area has mask coverage for strong adhesive bonding, while the thermal relief pad area is partially exposed for heat dissipation. This local differentiation resolves the contradiction between bonding integrity and heat dissipation.
Solution Approach 2:
The substrate surface is segmented into distinct functional zones: a die attach area with solder mask coverage and a thermal relief pad area with partial mask removal. This segmentation allows each zone to optimize its function - bonding in one area and thermal management in another - eliminating the delamination issue while maintaining heat dissipation.
2Strength
If solder mask is applied over thermal relief pads, then bonding strength is improved, but heat dissipation is reduced
Solution Approach 1:
The solder mask is selectively applied to create different surface properties in different areas: the die attach area has mask coverage for strong adhesive bonding, while the thermal relief pad area is partially exposed for heat dissipation. This local differentiation resolves the contradiction between bonding integrity and heat dissipation.
3Temperature
If die attach adhesive is applied directly to thermal relief pads, then heat transfer is maximized, but air entrapment causes bonding failure
Solution Approach 1:
The solder mask serves as an intermediary layer between the die attach adhesive and the thermal relief pads. It provides a bonding surface that eliminates air entrapment issues while still allowing heat transfer to the underlying thermal relief structure, thus resolving the bonding failure caused by air pockets.
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
The solution effectively reduces delamination and cracking issues, improving the thermal performance and reliability of the semiconductor package system by enhancing the bonding between the die attach adhesive and the substrate, thereby improving heat management and system integrity.
Implementation Method 1
depositing a mask on the substrate and the thermal relief, the mask deposited on the thermal relief and having a regular pattern to partially cover the thermal relief; and die attaching a semiconductor die over the thermal relief
Implementation Method 2
featuring a regular pattern such as a mesh or cross-hair design to enhance heat dissipation
Data Source
AI summary
A semiconductor package system including: providing a substrate having a thermal relief thereon; depositing a mask on the substrate and the thermal relief, the mask deposited on the thermal relief and having a regular pattern to partially cover the thermal relief; and die attaching a semiconductor die over the thermal relief.