Photo-thermal Interconnection Wire Bending for High-Density Packaging
Solution Overview
Problem
The traditional wire bonding process faces challenges in achieving ultra-high density interconnection due to limitations in capillary precision, leading to issues like friction and damage to gold wires, especially in advanced packaging where fine line diameters and large span low-arc requirements are difficult to meet.
Innovation Solution
A method involving a photo-thermal response conductive paste is used, where the paste is extruded through an air pressure injector to form an interconnection wire, and a linear light source is employed to bend the wire non-contactually, allowing precise control of bending angles and directions, avoiding damage and meeting high-density interconnection requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional wire bonding process is used with capillary, then wire bonding can be completed, but the capillary inner hole wall friction damages the gold wire surface
Solution Approach 1:
The patent replaces the traditional mechanical wire bonding system with a direct printing system that deposits conductive paste to form interconnection wires. This eliminates the capillary-wire mechanical contact and associated friction damage by using a non-contact deposition approach where the conductive paste is directly printed onto the substrate to create the interconnection path.
Solution Approach 2:
The patent introduces conductive paste as an intermediary material that replaces the direct mechanical interaction between capillary and gold wire. The paste is deposited through a printing head and then sintered to form the interconnection wire, eliminating the need for capillary-based mechanical wire feeding and bonding.
2Manufacturing precision
If ultra-high density interconnection is required, then line spacing must be reduced, but traditional equipment cannot achieve fine line diameters and large span low-arc requirements
Solution Approach 1:
The patent replaces complex mechanical wire bonding equipment with a direct printing system that uses a printing head to deposit conductive paste. This system achieves ultra-high density interconnection by precisely controlling the paste deposition pattern, line spacing, and line diameter through printing parameters rather than mechanical capillary positioning, thereby meeting fine line and large span requirements without increasing equipment complexity.
Solution Approach 2:
The patent achieves ultra-high density interconnection by changing the manufacturing parameters of the conductive paste deposition process, including paste viscosity, deposition speed, printing head height, and sintering conditions. These parameter adjustments enable precise control over line diameter and spacing to meet the required density specifications.
3Volume of moving object
If three-dimensional shape wire looping is implemented, then space utilization improves, but the capillary movement track becomes extremely complex
Solution Approach 1:
The patent replaces the mechanical capillary movement system with a direct printing system that deposits conductive paste in the desired three-dimensional wire loop pattern in a single printing operation. This eliminates the need for complex capillary movement tracks by using the printing head's precise positioning and paste deposition control to directly create the three-dimensional interconnection structure.
Solution Approach 2:
The patent implements the entire three-dimensional wire loop structure in a single printing operation by pre-programming the printing path and deposition parameters. The conductive paste is deposited layer by layer to form the complete three-dimensional wire loop structure before sintering, eliminating the need for subsequent mechanical manipulation or complex movement tracks.
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 method enables the creation of ultra-high density interconnections with controlled bending angles and directions, achieving fine line diameters, large span, and low line arc without physical contact, thus enhancing the reliability and precision of advanced packaging.
Implementation Method 1
a linear light source emits light and irradiates on the interconnection wire to bend a free end of the interconnection wire
Implementation Method 2
a photo-thermal response conductive paste is used, where the paste is extruded through an air pressure injector to form an interconnection wire, and a linear light source is employed to bend the wire non-contactually
Data Source
AI summary
A method for processing an ultra-high density interconnect wire under light source guidance, comprising preparing a photo-thermal response conductive paste, and putting it into an air pressure injector; driving the air pressure injector; the air pressure injector extrudes the photo-thermal response conductive paste, so that the photo-thermal response conductive paste is connected with the first chip to form an interconnection wire; stopping extruding the photo-thermal response conductive paste, and driving the air pressure injector to pull off the interconnection wire; a linear light source emits light and irradiates on the interconnection wire to bend to an upper side of a second chip bonding pad; an extrusion mechanism presses a free end of the interconnection wire on the second chip bonding pad; the first chip and the second chip are subjected to glue dripping encapsulation.