Image Sensor Package Glass Lid Cushioning Against Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor packages face challenges in providing a reliable and durable structure for image sensor dies, particularly in managing thermal stress and preventing delamination due to the use of liquid adhesives.
Innovation Solution
The implementation of a semiconductor package structure that includes a substrate, an image sensor die, a glass lid, and two molding compounds, with cushions or dams made of materials like epoxy, silicone, or acrylic positioned between the glass lid and the molding compounds, to enhance thermal stress management and prevent delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If liquid adhesives are used to bond the glass lid to the die, then the bonding process is simplified, but thermal stress management deteriorates and delamination risk increases
Solution Approach 1:
A cushion element made of compressible material (foam, rubber, or elastomer) is introduced as an intermediary between the glass lid and the die. This cushion serves as a mediator that absorbs thermal expansion stresses and prevents direct stress transmission to the adhesive bond, thereby eliminating delamination issues while maintaining bonding simplicity
Solution Approach 2:
The bonding approach transitions from relying solely on adhesive properties to incorporating a mechanical cushioning system. The cushion's compressibility parameter allows it to dynamically adjust to thermal expansion, changing the stress distribution characteristics and preventing adhesive failure
2Strength
If rigid structures are used to support the glass lid, then structural strength is improved, but thermal stress management deteriorates
Solution Approach 1:
The cushion element is constructed from flexible compressible material that can deform under thermal stress. This flexible component absorbs expansion forces through compression rather than transmitting them as rigid stresses, maintaining structural integrity while managing thermal effects
Solution Approach 2:
The compressible cushion is pre-installed between the glass lid and die to provide beforehand cushioning against thermal expansion. This pre-positioned cushioning element is designed to compress during thermal cycling, preventing stress concentration before delamination can occur
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 reduces the chances of delamination and improves the reliability of the semiconductor package by managing thermal stress through the use of flexible cushions or dams, thereby enhancing the overall performance and longevity of the image sensor devices.
Implementation Method 1
managing thermal stress and preventing delamination
Data Source
AI summary
Implementations of semiconductor packages may include: a substrate having a first side and a second side and a die having an active area on a second side of the die. A first side of the die may be coupled to the second side of the substrate. The semiconductor package may also include a glass lid having a first side and a second side. The glass lid may be coupled over a second side of the die. The semiconductor package may include a first and a second molding compound and one or more cushions positioned between a first side of the glass lid and a portion of the first molding compound. The second molding compound may be coupled to the substrate and the around the die and the glass lid.