MEMS Assembly Dicing Method for Bonding Pad Exposure
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Solution Overview
Problem
The existing manufacturing methods for MEMS assemblies face challenges in the dicing process, particularly in exposing bonding pads without damaging the sensor chip, which affects yield and reliability.
Innovation Solution
A novel manufacturing method involving two dicing processes of different depths is performed on a MEMS assembly, where a groove on the sensor chip allows for the exposure of bonding pads, facilitating lead-soldering and improving reliability, using mechanical or laser dicing techniques with specific positioning and dimensions to ensure effective substrate thinning and bonding layer compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single dicing process is used to expose bonding pads, then the bonding pads can be exposed, but the sensor chip is damaged during the dicing process
Solution Approach 1:
The dicing process is divided into two separate stages: a first dicing process that exposes the bonding pads without penetrating through the sensor chip, and a second dicing process that completes the separation after bonding. This segmentation allows each dicing operation to be optimized for its specific purpose, preventing chip damage while ensuring proper pad exposure.
Solution Approach 2:
The first dicing process is performed as a preliminary action before bonding to expose the bonding pads at the required depth. This preliminary exposure creates the necessary conditions for subsequent bonding and lead-soldering operations without requiring deep penetration that would damage the chip during final separation.
2Ease of operation
If the sensor chip is thinned to expose bonding pads, then bonding pads are exposed for soldering, but the sensor chip becomes vulnerable to damage
Solution Approach 1:
The first dicing process removes only the necessary amount of material to expose the bonding pads at the required depth, without excessive thinning that would compromise chip strength. This partial removal achieves the minimum necessary exposure for soldering while preserving structural integrity.
3Ease of operation
If deep dicing is performed to expose bonding pads, then bonding pads are accessible for external connection, but the dicing process becomes more complex and risky
Solution Approach 1:
The complex deep dicing operation is segmented into two simpler processes: first dicing to expose pads at controlled depth, and second dicing for final separation. This reduces the complexity and risk of each individual dicing operation while achieving the same overall goal of pad accessibility.
Data Source
AI summary
Disclosed a MEMS assembly and a manufacturing method thereof. The manufacturing method comprises: forming a groove on a sensor chip; forming a bonding pad on a circuit chip; bonding the sensor chip and the circuit chip together to form a bonding assembly; performing a first dicing process at a first position of the sensor chip to penetrate through the sensor chip to the groove; performing a second dicing process at a second position of the sensor chip to penetrate through the sensor chip and the circuit chip, for obtaining an individual MEMS assembly by singulating the bonding assembly, wherein location of the groove corresponds to a position of the bonding pad, and an opening is formed in the sensor chip to expose the bonding pad when the second dicing process is performed. The method uses two dicing process respectively achieving different depths to expose the bonding pad of the sensor chip and singulate the MEMS assembly, respectively, to improve yield and reliability.