Semiconductor Substrate Trenches Contain Resin Bleed-Out
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resin bleed-out from adhesive during flip chip semiconductor device assembly contaminates substrates and test boards, leading to production delays, increased costs, and potential device contamination due to ineffective existing solutions like metal strips.
Innovation Solution
Applying lid adhesive to gold surfaces on the substrate with a trench or gap between them to act as a reservoir for resin bleed-out, preventing contact with the substrate and containing resin effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lid adhesive is applied directly to the substrate, then assembly is simple, but resin bleed-out contaminates the substrate and LGA pads
Solution Approach 1:
The substrate surface is segmented into adhesive application areas (gold surfaces) and non-adhesive areas (trenches with LGA pads). This segmentation prevents resin bleed-out from reaching the LGA pads by confining the adhesive to specific zones, thereby eliminating contamination while maintaining assembly simplicity
Solution Approach 2:
Gold surfaces are introduced as intermediary layers between the lid adhesive and the substrate. The adhesive is applied to the gold surfaces rather than directly to the substrate, creating a barrier that prevents resin bleed-out from contaminating the substrate and LGA pads
2Object-affected harmful factors
If metal strips are added around substrate edges to prevent resin bleed-out, then edge contamination is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The harmful function of the substrate surface (absorbing resin through capillary action) is extracted from the entire substrate and confined to specific areas. By creating trenches that remove the problematic surface texture from the LGA pad areas, the solution prevents resin bleed-out without adding external components like metal strips
Solution Approach 2:
The substrate surface is modified with different qualities in different locations: smooth gold surfaces for adhesive application and rough trench areas for resin containment. This local differentiation prevents resin bleed-out at critical areas (LGA pads) while maintaining adhesive functionality elsewhere
3Reliability
If manual cleaning of resin bleed-out is performed, then device quality is maintained, but production time and costs increase
Solution Approach 1:
The substrate is prepared in advance with gold surfaces and trenches that prevent resin bleed-out before the adhesive application process. This preliminary structuring of the substrate ensures that resin contamination does not occur during assembly, eliminating the need for subsequent cleaning operations and maintaining high production speeds
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
Significantly reduces resin contamination on LGA pads and test sockets, eliminates production delays, and enhances device reliability and quality by containing resin bleed-out during assembly.
Implementation Method 1
The capillary effect of the ceramic surface roughness drives the resin away from the adhesive matrix. The ceramic substrate essentially sucks up the resin from the adhesive.
Implementation Method 2
lid adhesive is applied to gold surfaces formed on a semiconductor substrate, thereby minimizing resin bleed-out contamination from the adhesive
Data Source
AI summary
System and method for preventing resin-based adhesive from contacting a substrate to minimize resin bleed-out and contamination. A preferred embodiment comprises a semiconductor device having a die mounted on a substrate, first and second gold surfaces formed on the substrate, a trench formed between the first and second gold surfaces, resin-based adhesive applied to the first gold surface, and a heat sink bonded to the resin-based adhesive.