Ceramic Substrate Capillary Microgrooves for Demetallized Chip Soldering
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Solution Overview
Problem
The existing ceramic substrate production processes for LED chip substrates are complex and costly due to the need for metalizing, particularly when using the flip chip mode, which involves copper plating and electrode formation, making batch production difficult and expensive.
Innovation Solution
A demetallized ceramic substrate with a surface capillary microgroove structure and a corresponding welding method that eliminates the need for metalizing processes by using capillary microgrooves formed on the ceramic substrate, allowing for a reliable electrical connection through capillary-driven soldering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metalizing processes (copper plating, electrode formation) are used to ensure reliable electrical connection, then electrical connection reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the metalizing processes (copper plating, electrode formation) from the ceramic substrate manufacturing process. Instead of adding metal layers to the ceramic substrate, the invention uses the ceramic substrate itself with capillary microgrooves to achieve electrical connection, thereby simplifying the manufacturing process while maintaining connection reliability through capillary-driven soldering
Solution Approach 2:
The patent introduces capillary microgrooves as an intermediary structure between the ceramic substrate and the solder. These microgrooves act as a mediator that guides and drives the solder to the correct position through capillary action, replacing the need for metal electrodes while ensuring reliable electrical connection
2Reliability
If metalizing processes are adopted for flip chip mode, then electrical connection is achieved, but production cost and process complexity increase
Solution Approach 1:
The patent removes the expensive metalizing steps (copper plating, electrode formation) from the production process. The demetallized ceramic substrate uses only ceramic material with laser-formed capillary microgrooves, significantly reducing material costs and process complexity while maintaining electrical connection capability through capillary soldering
Solution Approach 2:
The patent replaces the mechanical/electrical metal plating system with a thermal-field system. Laser machining creates the capillary microgrooves, and then thermal energy (heating) drives the capillary action of solder to achieve electrical connection, substituting complex electrochemical metalizing processes with simpler thermal and capillary mechanisms
3Manufacturing precision
If capillary microgrooves are formed by laser machining, then manufacturing precision is improved, but production time increases
Solution Approach 1:
The patent segments the ceramic substrate processing into distinct stages: laser machining of capillary microgrooves is performed on individual substrates with high precision, then multiple processed substrates are assembled together. This segmentation allows high-precision laser machining to be performed on smaller components rather than requiring entire production batches to be processed simultaneously, maintaining precision while improving overall production throughput
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
Simplifies the production process, reduces costs, and ensures reliable electrical connections between the chip and the printed circuit board, enabling efficient batch production while eliminating the need for copper plating and other metalizing steps.
Implementation Method 1
placing a melted solder on the bonding pad, and driving the solder to ascend to an electrode of the chip from the bonding pad in a lower layer by means of a capillary force
Data Source
AI summary
The present invention discloses a welding method of a demetallized ceramic substrate having a surface capillary microgroove structure. The demetallized ceramic substrate includes a ceramic substrate main body and surface capillary microstructures. The surface capillary microstructures are arranged on two lateral sides of the ceramic substrate main body and the surface capillary microstructures specifically are capillary microgrooves. The welding method includes the following steps: fixing a chip to an upper surface of the demetallized ceramic substrate having the surface capillary microgroove structure, fixing the ceramic substrate with the chip to a printed circuit board having a bonding pad, and placing melted solder on the bonding pad, and driving the solder to ascend to an electrode of the chip from the bonding pad in a lower layer by means of a capillary force, thereby realizing an electrical connection between the chip and the printed circuit board.