LED Chip Recesses for Eutectic Bonding Stability
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Solution Overview
Problem
The conventional eutectic bonding process for light-emitting diode (LED) packaging is prone to failures due to chip shifting or rotation during heating, leading to electrical shortages or broken circuits, and the pressing process increases manufacturing complexity and cost while reducing throughput.
Innovation Solution
A light-emitting diode package design featuring recesses at the corners of the chip to embed metal pillars, which are formed on a carrier and eutectically bonded to prevent shifting, eliminating the need for pressing and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressing process is used in eutectic bonding to prevent chip shifting, then bonding reliability is improved, but manufacturing complexity and cost increase while throughput decreases
Solution Approach 1:
The patent applies preliminary action by forming recesses at the corners of the LED chip before the eutectic bonding process. These recesses are prepared in advance to receive and constrain the metal pillars, preventing chip shifting during heating without requiring additional pressing equipment or processes. This preliminary structural preparation eliminates the need for complex pressing mechanisms while maintaining bonding reliability.
2Reliability
If the pressing process is used in eutectic bonding to prevent chip shifting, then bonding reliability is improved, but manufacturing cost increases
Solution Approach 1:
The recesses are formed on the LED chip before bonding, creating a cost-effective solution that eliminates the need for expensive pressing equipment. The metal pillars are subsequently formed on the carrier to match these recesses, providing a low-cost mechanism to prevent chip shifting during eutectic bonding while maintaining high bonding reliability.
3Reliability
If the pressing process is used in eutectic bonding to prevent chip shifting, then bonding reliability is improved, but productivity decreases
Solution Approach 1:
By forming recesses and metal pillars before the bonding process, the patent eliminates the need for time-consuming pressing operations during production. The recesses and metal pillars are prepared in advance, allowing the eutectic bonding to proceed without additional pressing steps, thereby increasing throughput and productivity while maintaining bonding reliability.
4Reliability
If metal pillars are formed to embed into recesses, then chip shifting is prevented, but device structure complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the bonding interface into distinct functional elements: recesses formed on the LED chip and corresponding metal pillars formed on the carrier. This segmentation creates a modular constraint system where each recess-metal pillar pair independently prevents shifting, providing simple and effective chip positioning stability without excessive structural complexity.
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 effectively prevents chip shifting and rotation during heating, reducing bonding process failures and electrical issues, while simplifying manufacturing, reducing costs, and increasing throughput by embedding metal pillars into recesses on the LED chip.
Implementation Method 1
melting the metal pillar by heating such that an upper portion of the metal pillar covers a portion of a top surface of the light-emitting diode chip
Implementation Method 2
the eutectic bonding process is a common die attach method. In the eutectic bonding process, eutectic metal is formed on the surface of the light-emitting diode chip or the surface of the carrier, then the light-emitting diode chip and the carrier are eutectically bonded. Then, the eutectic bonding process is completed by heating.
Data Source
AI summary
The present disclosure provides a light-emitting diode package, including: a carrier; a light-emitting diode chip disposed over the carrier and electrically connected to the carrier, wherein the light-emitting diode chip includes at least two recesses at corners located on a diagonal line of the light-emitting diode chip; a eutectic layer disposed between the light-emitting diode chip and the carrier, wherein the eutectic layer includes at least two metal pillars embedded into the at least two recesses respectively, wherein an upper portion of the metal pillars covers a portion of a top surface of the light-emitting diode chip. The present disclosure also provides a method for manufacturing a light-emitting diode package.