Vented Heat-Spreader for IC Package Solvent Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current flip-chip package designs face issues with corrosive solvents entering the package through adhesive gaps, causing corrosion of components due to incomplete removal during the soldering process, and difficulty in sealing these gaps for effective gas escape and liquid prevention.
Innovation Solution
A vented heat-spreader design with a central region thermally coupled to the semiconductor die, a flange region mounted on the substrate, and a sidewall region forming a cavity, featuring vents that can be sealed with membranes or adhesive tape to prevent solvent ingress while allowing gas escape, ensuring a liquid-tight seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the heat-spreader is attached to the substrate using adhesive with a gap to allow gas expansion escape, then gas escape is enabled, but corrosive solvent can enter through the gap and corrode components
Solution Approach 1:
The adhesive attachment is segmented into two functional zones: a sealed perimeter region that prevents solvent ingress, and a vent region that allows gas expansion escape. This segmentation enables the adhesive to simultaneously perform both protective and venting functions without compromise.
Solution Approach 2:
Different regions of the adhesive attachment have different properties: the perimeter region has high sealing quality to block solvent, while the vent region has high permeability to allow gas escape. This local differentiation of adhesive properties resolves the contradiction between sealing and venting requirements.
2Object-affected harmful factors
If the adhesive gap is sealed to prevent solvent entry, then solvent corrosion is prevented, but gas expansion cannot escape and may cause separation
Solution Approach 1:
The adhesive attachment is segmented into two functional zones: a sealed perimeter region that prevents solvent ingress, and a vent region that allows gas expansion escape. This segmentation enables the adhesive to simultaneously perform both protective and venting functions without compromise.
Solution Approach 2:
The vent region acts as an intermediary pathway that allows gas expansion to escape while the sealed perimeter prevents solvent entry. This intermediary venting mechanism resolves the contradiction by providing a dedicated escape route for gas that does not compromise the solvent barrier.
3Object-affected harmful factors
If complete cleaning of corrosive solvent residue is performed, then solvent corrosion is prevented, but it is difficult to fully remove all traces from within the enclosed space
Solution Approach 1:
The vent region is built into the adhesive attachment structure before final assembly, providing continuous access to the enclosed space. This preliminary design feature enables effective cleaning and flushing operations to remove solvent residues without requiring disassembly or complex access mechanisms.
Solution Approach 2:
The vent region acts as an intermediary pathway that allows cleaning agents to access and flush the enclosed space effectively. This continuous access pathway enables complete removal of corrosive solvent residues, resolving the cleaning accessibility problem.
4Object-affected harmful factors
If a hermetic seal is used to prevent solvent entry, then solvent corrosion is prevented, but gas expansion has no escape path and may cause separation
Solution Approach 1:
The adhesive attachment is segmented into two functional zones: a sealed perimeter region that prevents solvent ingress, and a vent region that allows gas expansion escape. This segmentation enables the adhesive to simultaneously perform both protective and venting functions without compromise.
Solution Approach 2:
Different regions of the adhesive attachment have different properties: the perimeter region has high sealing quality to block solvent, while the vent region has high permeability to allow gas escape. This local differentiation of adhesive properties resolves the contradiction between sealing and venting requirements.
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 vented heat-spreader effectively prevents solvent entry and corrosion, ensuring reliable operation by allowing gas escape while maintaining a seal against liquids, enhancing the durability and reliability of integrated circuit packages.
Implementation Method 1
The heat-spreader includes a central region thermally coupled to the second surface of the semiconductor die
Implementation Method 2
gasses generated during out-gassing must be allowed to escape the enclosed package
Data Source
AI summary
An integrated circuit package assembly includes a substrate, a semiconductor die having opposing first and second surfaces, and a head-spreader. The semiconductor die is mounted on the substrate with the first surface facing the substrate. The heat-spreader includes a central region thermally coupled to the second surface of the semiconductor die, a flange region mounted on the substrate, and a side wall region between the central and flange regions. A cavity is formed between the heat-spreader, the substrate, and the semiconductor die. The heat-spreader has at least one vent extending from the cavity through the heat-spreader.