Semiconductor Assembly Moulding with Solder Removal Against Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods of manufacturing semiconductor assemblies are prone to delamination due to stress from thermal expansion and mechanical deformation, leading to potential device failure from moisture ingress.
Innovation Solution
A method involving securing a die to a die paddle with solder, forming a clip secured to the die with solder, heating the subassembly to melt the solder, removing excess solder from the die paddle to expose it, and moulding a casing around the subassembly to enhance bonding and reduce delamination risk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the casing is moulded onto the components, then the die and other components are protected, but delamination can occur due to stress from thermal expansion and mechanical deformation
Solution Approach 1:
By removing excess solder from the die paddle surface before casing application, the patent eliminates a potential weak point in the bonding structure. This ensures that the casing bonds directly to the die paddle material rather than to solder, creating a more stable and stress-resistant bond that prevents delamination
Solution Approach 2:
The patent creates a localized exposed region on the die paddle where the solder has been removed. This local modification provides an optimal bonding surface specifically for the casing application, enhancing the local bond quality in the critical bonding zone while leaving other areas unchanged
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 method improves the bond strength between the casing and the subassembly, reducing the likelihood of delamination and enhancing the reliability of the semiconductor device.
Implementation Method 1
heating the first subassembly to at least the melting temperature of the solder
Implementation Method 2
The solder may be removed from the die paddle using laser ablation
Data Source
Figure 1
Figure 2~6
Figure 7a~9
AI summary
There is disclosed a method of manufacturing a semiconductor device. The method comprises securing a die to a die paddle with solder and securing a clip to the die with solder to form a first subassembly. The method further comprises heating the first subassembly to at least the melting temperature of the solder, then subsequently removing at least some of the solder from the die paddle in a region adjacent the die to expose the die paddle in that region. The method further comprises moulding a casing on to the first subassembly such that the casing at least partly surrounds the die, the die paddle, and the clip.