Semiconductor Package Structure Eutectic Bonding Void Elimination
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Solution Overview
Problem
Existing semiconductor package technologies using non-conductive paste often result in voids and packaging defects due to incomplete filling and alignment issues between metal pillars and bumps, leading to short circuits and manufacturing inefficiencies.
Innovation Solution
A package structure and method that involves bonding a die with a metal pillar to a metal plate, covering it with an insulating film, and forming a circuit structure electrically connected to the pillar without using non-conductive paste, allowing for direct lamination and improved alignment and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-conductive paste is used to bond die to circuit board, then bonding is achieved, but voids occur and short circuits happen
Solution Approach 1:
The patent removes the non-conductive paste from the bonding process entirely. Instead, it uses a metal plate with metal patterns that directly bond to the die's metal pillars through eutectic bonding, eliminating the source of voids and short circuits associated with paste usage.
Solution Approach 2:
The patent replaces the mechanical paste-based bonding system with a thermal-field-based eutectic bonding system. The metal plate and metal pillars are bonded through controlled heating that triggers eutectic reaction, creating a reliable metal-to-metal bond without voids.
2Ease of manufacture
If non-conductive paste is used for bonding, then die attachment is achieved, but alignment between metal pillars and metal bumps becomes difficult
Solution Approach 1:
The patent pre-forms metal patterns on the metal plate at precise positions before die attachment. These pre-positioned metal patterns serve as alignment references that guide the die's metal pillars into correct alignment during the bonding process, eliminating alignment difficulties.
Solution Approach 2:
The patent replaces the paste-based alignment system with a direct metal-to-metal eutectic bonding system. The controlled thermal field during eutectic bonding enables precise alignment between metal pillars and metal patterns without the tolerance issues of paste application.
3Reliability
If protective films like epoxy molding compounds are used, then die protection is achieved, but package thickness increases
Solution Approach 1:
The patent removes the epoxy molding compound protective film from the package structure. Instead, it uses the metal plate itself as both the bonding substrate and the protective element, eliminating the need for additional protective layers and reducing overall thickness.
Solution Approach 2:
The metal plate serves multiple functions simultaneously: it acts as the bonding substrate for die attachment, provides electrical connection through metal patterns, and serves as the protective structure. This multi-functionality eliminates the need for separate protective films.
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 prevents voids, enhances heat radiating efficiency, and improves the matching degree of metal pillars with circuit structures, reducing packaging defects and overall thickness while eliminating the need for protective films like epoxy molding compounds.
Implementation Method 1
a first package structure in which the other surface of the die is bonded to the metal plate through eutectic bonding
Implementation Method 2
The insulating film may be formed by directly laminating the insulating film on the metal plate and the die
Implementation Method 3
The circuit structure may be formed by performing a plating process on the insulating film
Data Source
AI summary
Disclosed herein is a method for manufacturing a package structure. According to an exemplary embodiment of the present invention, the method for manufacturing a package structure includes: preparing a die having a metal pillar disposed on one surface thereof; bonding the die on the metal plate to allow the metal pillar to face the outside; forming an insulating film covering the metal plate and the die; buffing the insulating film so as to expose the metal pillar; and manufacturing a first package structure by forming a circuit structure electrically connected to the metal pillar on the insulating film.