LED Flip Chip Die-Bond via Metal-Metal Contact
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Solution Overview
Problem
Current Anisotropic Conductive Adhesives (ACAs) face challenges such as high production costs, low conductivity, poor toughness, unstable adhesive effects, long curing times, and complex manufacturing processes, limiting their application in LED flip chip die-bonding.
Innovation Solution
A thermosetting die-bond insulating adhesive is used to establish a direct metal-metal contact between the LED flip chip and the electronic circuit board, with a simplified process and equipment, enabling efficient large-scale automatic production and improved conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Anisotropic Conductive Adhesive (ACA) is used for LED flip chip die-bond conductive connection, then conductivity is achieved, but production cost increases and manufacturing complexity increases
Solution Approach 1:
The patent extracts the conductive function from the adhesive layer by creating direct metal-to-metal contact between the LED chip electrodes and substrate pads through via holes, eliminating the need for conductive particles in the adhesive. This removes the complexity of selecting and formulating conductive fillers while maintaining reliable electrical connection.
Solution Approach 2:
The patent segments the bonding process into distinct functional zones: insulating adhesive areas for mechanical bonding and isolated conductive via holes for electrical connection. This segmentation allows the use of simple, low-cost insulating adhesives without conductive particles, while achieving conductivity through the structured via hole arrangement.
2Reliability
If Anisotropic Conductive Adhesive (ACA) is used for LED flip chip die-bond, then conductive connection is established, but curing time increases and productivity decreases
Solution Approach 1:
The patent removes the requirement for long curing times associated with ACA by using conventional fast-curing insulating adhesives. The conductive function is achieved through pre-formed metal via holes that provide immediate electrical connection upon bonding, eliminating the need for extended thermal or UV curing processes.
3Reliability
If metal particles are used as conductive fillers in ACA, then conductivity is improved, but cost increases and adhesive stability deteriorates
Solution Approach 1:
The patent completely removes metal particles from the adhesive composition, using only insulating adhesive materials. Conductivity is achieved through the physical structure of metal via holes that create direct contact paths, eliminating all stability issues related to metal particle oxidation, aggregation, or migration in the adhesive matrix.
4Reliability
If direct metal-metal contact is implemented, then conductivity is enhanced and heat dissipation is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent performs preliminary formation of metal via holes in the substrate before the bonding process. These pre-formed via holes serve as alignment guides and contact targets, reducing the precision requirements for chip placement. The via holes are positioned in advance to match the electrode locations, ensuring reliable metal-to-metal contact without requiring ultra-precise real-time alignment during bonding.
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 solution reduces production and processing costs, enhances conductivity, and extends the service life of LED flip chips by facilitating rapid heat dissipation, while being versatile for various circuit boards and allowing small-spacing die-bonding.
Implementation Method 1
heating and shrinking volume of the thermosetting die-bond insulating adhesive after cooling, thereby realizing metal-metal contact type conductive connection
Data Source
AI summary
An LED flip chip die-bond conductive adhesive structure includes an LED flip chip and an electronic circuit board. An LED flip chip negative electrode, an LED flip chip nonmetallic region and an LED flip chip positive electrode are sequentially arranged on a lower surface of the LED flip chip from left to right; a circuit board negative electrode, a circuit board nonmetallic region and a circuit board positive electrode are sequentially arranged on an upper surface of the electronic circuit board from left to right. The LED flip chip and the electronic circuit board are fixedly connected through a thermosetting die-bond insulating adhesive bonded between the LED flip chip nonmetallic region and the circuit board nonmetallic region; and the LED flip chip positive and negative electrodes are respectively conductively connected with the circuit board positive and negative electrodes in a direct metal-metal contact manner.