Chip Carrier Baffle for Flip Chip Gas Management
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Solution Overview
Problem
In flip chip bonding technology, the release of scorching gas from the adhesive layer during heating leads to bubble formation between the thin film and the affixture layer, causing poor connection and reduced yield in electronic package structures.
Innovation Solution
A baffle is placed between the chip and thin film attachment regions on the chip carrier to redirect and contain the released gas, preventing it from interfering with the bonding between the thin film and affixture layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the chip and thin film are attached to the chip carrier using adhesive layers and heating, then bonding strength is improved, but bubbles are formed between the thin film and affixture layer due to gas release
Solution Approach 1:
The chip carrier surface is segmented into distinct regions: a chip attachment region, a film attachment region, and a gas collection region. The gas collection region is created by removing affixture layer material to form a depression or void space positioned adjacent to the film attachment region. This segmentation allows gas to be directed away from the bonding interface during heating, preventing bubble formation while maintaining strong bonding in the film attachment region.
2Strength
If heating is applied to the adhesive layer to enhance bonding, then adhesive activation is improved, but scorching gas is released that degrades the bonding between thin film and affixture layer
Solution Approach 1:
The harmful gas is extracted from the bonding region by creating a dedicated gas collection region through selective removal of affixture layer material. This extracted gas is directed into the void space formed by the removed material, separating it from the film attachment region where bonding occurs. This allows the adhesive to be heated and activated without the harmful effects of scorching gas interfering with the thin film bonding.
3Reliability
If the thin film is attached to the affixture layer, then electrical connection is established, but bubbles formed during bonding cause peeling and poor connection
Solution Approach 1:
The affixture layer material is preliminarily removed in the gas collection region before the bonding process begins. This preliminary action creates a pre-configured gas collection region that will capture and contain gas during subsequent heating and bonding operations. By preparing this gas collection pathway in advance, the bonding process can proceed without gas interfering with the thin film to affixture layer adhesion, ensuring stable bonding integrity and reliable electrical connection.
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
This solution effectively prevents bubble formation and maintains a good electrical connection, enhancing the yield and reliability of the electronic package structure by isolating the gas from the bonding area.
Implementation Method 1
the adhesive of the ACF will release scorching gas under high temperature
Implementation Method 2
heat is transfer from the chip 124 to the adhesive layer 122
Data Source
AI summary
The present invention provides an electronic packaging process. The surface of the chip carrier includes at least a chip attachment region and a film attachment region adjacent to the chip attachment region. At least a baffle is formed on the surface of the chip carrier, between the chip attachment region and the film attachment region. After attaching the thin film to the film attachment region of the chip carrier through an affixture layer, the chip is electrically and physically connected to the chip attachment region of the chip carrier through an adhesive layer. The baffle can effectively prevent the gas that is released from the adhesive layer from damaging the bonding between the thin film and the affixture layer. Therefore, almost no bubbles are formed and good electrical connection between the thin film and the affixture layer is maintained.