Image Sensor Chip Package Structure for Thin Sheet Protection
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Solution Overview
Problem
Conventional chip packages for image sensing with light transmissive sheets face challenges in thinner design due to excessive sheet thickness and susceptibility to damage during the wafer-level packaging process, where the sheets are easily broken and damaged after cutting.
Innovation Solution
A chip package design featuring a light transmissive sheet with a protruding portion, a bonding layer, and an insulating layer that extends from the chip's surface to the protruding sheet, allowing the insulating layer to cover and protect the sidewalls, along with a manufacturing method that involves bonding, grinding, and cutting to achieve a thinner design while maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the light transmissive sheet is made thinner to enable thinner design, then the design flexibility is improved, but the sheet becomes more susceptible to breaking and damage during the wafer-level packaging process
Solution Approach 1:
The patent applies beforehand cushioning by creating a protruding portion on the light transmissive sheet that extends beyond the chip sidewalls before the cutting process. This protruding structure acts as a protective buffer that prevents the thin sheet from breaking during subsequent manufacturing steps, allowing the sheet to be made thinner while maintaining reliability.
Solution Approach 2:
The patent implements preliminary action by forming the protruding portion on the light transmissive sheet before the wafer is cut into chips. This advance preparation ensures that the thin sheet has structural support in place before the cutting process begins, preventing damage that would occur if the sheet were thin without the protruding portion.
2Strength
If the light transmissive sheet is made thicker to provide supporting force, then the structural strength is improved, but the design flexibility for thinner packages is reduced
Solution Approach 1:
The patent applies another dimension by extending the light transmissive sheet vertically beyond the chip sidewalls to create a protruding portion. This dimensional extension provides the necessary supporting force and structural strength without increasing the horizontal thickness of the sheet, thus maintaining design flexibility for thin packages while achieving the required strength.
Solution Approach 2:
The patent segments the light transmissive sheet into two functional zones: a thin region that contacts the chip surface for optical performance, and a protruding portion that extends beyond the chip sidewalls for mechanical support. This segmentation allows the sheet to provide supporting force through its extended structure without requiring increased overall thickness.
3Productivity
If the wafer is cut into chips after bonding to the light transmissive sheet, then the manufacturing efficiency is improved, but the sidewalls of the chips and light transmissive sheets become exposed and easily damaged
Solution Approach 1:
The patent applies beforehand cushioning by creating the protruding portion on the light transmissive sheet before the cutting process. This protruding structure acts as a protective buffer that prevents the thin sheet from breaking during subsequent manufacturing steps, allowing the sheet to be made thinner while maintaining reliability.
Data Source
AI summary
A chip package includes a light transmissive sheet, a chip, a bonding layer, and an insulating layer. The light transmissive sheet has a protruding portion. A first surface of the chip faces toward the light transmissive sheet and has a sensing area. The bonding layer is located between the chip and the light transmissive sheet. The sum of a thickness of the chip and a thickness of the bonding layer is greater than or equal to a thickness of the light transmissive sheet. A protruding portion of the light transmissive sheet protrudes from a sidewall of the chip and a sidewall of the bonding layer. The insulating layer extends from a second surface of the chip to the protruding portion of the light transmissive sheet along the sidewall of the chip and the sidewall of the bonding layer.