Thin Die Detachment Control System for Crack Prevention
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Solution Overview
Problem
Conventional die pick-up tools are inadequate for detaching thin semiconductor dice from adhesive tapes without causing damage, as they often exceed the critical strength of the dice, leading to cracking due to pinching effects and bending deformations.
Innovation Solution
A real-time monitoring and control system that supports the die with movable plates, applies vacuum suction, and monitors pressure to ensure the peeling energy does not exceed the critical strength, using a feedback system to optimize the detachment process and prevent cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ejector pins are used to detach the die from the adhesive tape, then the die can be detached and picked up, but the die may crack or break due to pinching effect and bending deformation
Solution Approach 1:
The ejector mechanism is segmented into multiple ejector pins that can be independently controlled. This allows selective activation of pins based on die size and position, distributing the detachment force more evenly and reducing localized pinching effects that cause cracking.
Solution Approach 2:
The ejector pins are designed with dynamic control capabilities, allowing real-time adjustment of pin extension depth and activation timing. This dynamic adjustment optimizes the detachment process for different die thicknesses and positions, minimizing bending deformation while ensuring complete separation from the adhesive tape.
2Reliability
If multiple ejector pins are used to achieve uniform push-up force, then the pinching effect is reduced, but the device complexity increases
Solution Approach 1:
The ejector mechanism is designed with multi-functionality, where the same set of ejector pins can handle various die sizes and positions by selective activation. The system universally applies to different die configurations without requiring separate mechanisms, achieving uniform force distribution while maintaining reasonable complexity through programmable control.
3Length of moving object
If the die thickness is reduced to below 100 microns to achieve thinner semiconductor products, then product miniaturization is improved, but the die becomes more susceptible to cracking during detachment
Solution Approach 1:
The ejector pins incorporate dynamic depth control that adapts to different die thicknesses. For thinner dice (below 100 microns), the system automatically limits pin extension depth to prevent excessive push-up force that would cause cracking, while still achieving effective detachment through controlled peeling action.
Solution Approach 2:
The system employs feedback control mechanisms that monitor detachment progress and adjust pin activation in real-time. This feedback ensures that the force applied to thin dice remains within safe limits, preventing cracking while maintaining detachment effectiveness. The system can detect resistance changes and modify pin extension accordingly.
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 system effectively reduces the incidence of die cracking during detachment by ensuring the peeling energy does not exceed the critical strength, allowing for reliable handling of thin dice without damage.
Implementation Method 1
The collet provides vacuum suction using a vacuum generator to hold the die during the detachment process
Implementation Method 2
A vacuum channel is enclosed by the ejector cap in order to provide vacuum suction to the adhesive tape for aiding in the delamination of the die
Data Source
AI summary
During detachment of a die from an adhesive tape, the inner and outer portions of a first side of the die which is in contact with the adhesive tape is supported with a support surface. A collet contacts the inner and outer portions of a second side of the die opposite to the first side. Support is withdrawn from the outer portion of the die such that the outer portion of the second side of the die bends away from the collet while the support surface only supports the inner portion of the die. Vacuum suction from the collet is applied to attract the outer portion of the die towards the collet and the vacuum suction pressure is monitored until a threshold pressure is reached indicating that the outer portion of the die is contacting the collet. Thereafter, the collet is lifted while holding the die with vacuum suction to completely separate the die from the adhesive tape.