3D Printed Chip-to-PCB Connections Using LIFT and Laser Sintering
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Solution Overview
Problem
Current additive manufacturing (AM) technologies for 3D structural electronics face limitations in conductivity, durability, and mechanical properties, restricting their application to simple devices that do not withstand mechanical shock, vibration, large current or power densities, temperature extremes, or high reliability requirements.
Innovation Solution
A method using laser-induced forward transfer (LIFT) to apply a liquid support material on a PCB with connectors and components, followed by curing and printing a conductive material layer to electrically connect them, and then sintering metal particles with a laser beam, forming a stable connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional wire bonding or bump bonding methods are used to connect chip terminals to substrate connectors, then electrical connection is achieved, but the process is time-consuming, labor-intensive, and prone to human error
Solution Approach 1:
The patent replaces conventional mechanical wire bonding and bump bonding processes with a 3D printing system that uses extruded conductive material. The 3D printing process automatically extrudes conductive polymer or metal material through precision-controlled nozzles to form conductive pathways between chip terminals and substrate connectors, eliminating the need for manual wire bonding equipment and procedures.
Solution Approach 2:
The patent changes the material state and deposition method by using extruded conductive material in a controlled 3D printing process. The conductive material is extruded in a controlled manner through precision-controlled nozzles, allowing precise control over the geometry and position of conductive pathways, thereby achieving high-precision electrical connections without conventional bonding methods.
2Reliability
If manual wire bonding or bump bonding is performed, then electrical connections are formed, but the skill level required is high and human error is inevitable
Solution Approach 1:
The 3D printing system performs the electrical connection process autonomously without requiring skilled manual operations. The system automatically extrudes conductive material through precision-controlled nozzles, follows predetermined pathways, and forms connections based on digital models, eliminating the need for highly skilled technicians and reducing human error in the connection process.
Solution Approach 2:
The patent replaces complex manual mechanical bonding operations with an automated 3D printing system that uses extruded conductive material. This substitution eliminates the need for skilled manual wire bonding or bump bonding techniques, making the process more reliable and easier to operate while maintaining high connection quality.
3Adaptability or versatility
If conventional bonding methods are used, then electrical connections are established, but the process is not scalable and cannot accommodate varying connector configurations
Solution Approach 1:
The 3D printing system is designed to handle various connector configurations and chip layouts through a universal process. The system can accommodate different numbers of connectors, varying positions, and different electrical connection requirements by simply changing the digital model parameters, making it highly adaptable and scalable for different product configurations without requiring process retooling.
Solution Approach 2:
The patent employs preliminary digital modeling and programming of the 3D printing process before actual manufacturing. The conductive pathways are pre-planned in digital space, allowing the system to automatically adapt to varying connector configurations through programmed instructions, thereby achieving both flexibility and scalability in the manufacturing process.
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 method enhances the reliability and durability of 3D structural electronics by providing stable electrical connections suitable for complex devices with high mechanical and electrical demands.
Implementation Method 1
the extruded material forms conductive pathways through the chip and substrate, establishing electrical connections between the terminals and the connectors
Data Source
Figure 1A~1B
Figure 1C
Figure 1D
AI summary
A method for fabricating a three-dimensional (3D) electronic device. A liquid support material (e.g., an epoxy acrylate with a photoinitiator) is applied by a laser-induced forward transfer (LIFT) process to a printed circuit board (PCB) having one or more connectors and one or more electronic components thereon, and then cured to solid form by cooling and/or exposure to ultraviolet (UV) radiation. A layer of conductive material (e.g., a metal) is printed on the solidified support material by LIFT to electrically connect the one or more electronic components to respective ones of the connectors on the PCB. Subsequently, the layer of conductive material is dried by heating and metal particles in the conductive layer sintered using a laser beam. The assembly may then be encapsulated in an encapsulant.