Bonding Tool Thermal Gradient for Semiconductor Chip Stacking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing bonding methods for semiconductor devices face challenges in achieving efficient three-dimensional structures due to the mismatch in heat resistance temperatures between thermosetting resin films and solder balls, leading to either deterioration of the resin or insufficient melting of the solder, which affects the electrical connection between memory chips and substrates.
Innovation Solution
A bonding apparatus with a specialized bonding tool that differentiates between the central and peripheral areas in terms of heat transfer, using a combination of recesses, cooling air flow paths, and materials with varying thermal conductivity to control the temperature distribution, allowing for separate heat management of the center and edge of the bonding member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the memory chip is heated to the melting temperature of the bonding metal, then the solder ball melts and electrical connection is achieved, but the thermosetting resin film deteriorates
Solution Approach 1:
The bonding tool is divided into a central portion and a peripheral portion with different thermal conductivities. The central portion has lower thermal conductivity to reduce heat transmission to the resin film, while the peripheral portion has higher thermal conductivity to efficiently melt the solder ball. This local differentiation allows simultaneous achievement of solder melting and resin protection.
Solution Approach 2:
The bonding tool's heating surface is segmented into distinct zones: a central area with reduced heat transmission capability and a peripheral area with enhanced heat transmission capability. This segmentation enables independent thermal control for different functional requirements - protecting the resin in the center while ensuring solder melting at the periphery.
2Ease of manufacture
If the memory chip is heated uniformly, then the bonding process is simplified, but the temperature distribution cannot satisfy both resin curing and solder melting requirements
Solution Approach 1:
Instead of uniform heating, the bonding tool implements local quality variation through different thermal conductivity materials in central and peripheral portions. This allows the system to maintain simple uniform heating operation while achieving non-uniform temperature distribution that satisfies both resin curing and solder melting requirements.
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 approach enables the bonding apparatus to heat the center of the bonding member to a lower temperature than the peripheral edge, ensuring the thermosetting resin film is not deteriorated while the solder ball melts, thereby establishing a reliable electrical connection without damage.
Implementation Method 1
a cooling flow path through which cooling air flows is provided in the first central area of the bonding tool
Implementation Method 2
an amount of heat per unit area of the bonding member that is transmitted from the first central area of the bonding tool to the center of the bonding member is smaller than an amount of heat per unit area of the bonding member that is transmitted from the first peripheral area of the bonding tool to a peripheral edge of the bonding member
Implementation Method 3
the DAF is thermally cured, a central portion of the memory chip is adhered and fixed to the control chip
Implementation Method 4
the solder ball melts, and the memory chip and the substrate are electrically connected
Data Source
AI summary
The present invention has: a heater; and a bonding tool having a lower surface on which a memory chip is adsorbed; and an upper surface attached to the heater, and is provided with a bonding tool which presses the peripheral edge of the memory chip to a solder ball in a first peripheral area of the lower surface and which presses the center of the memory chip (60) to a DAF having a heat resistance temperature lower than that of the solder ball in a first center area. The amount of heat transmitted from the first center area to the center of the memory chip is smaller than that transmitted from the first peripheral area (A) to the peripheral edge of the memory chip. Thus, the bonding apparatus in which the center of a bonding member can be heated to a temperature lower than that at the peripheral edge can be provided.