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Preparation method of pad for flip-chip led chip

An LED chip and flip-chip technology, applied in semiconductor devices, electrical components, circuits, etc., can solve the problems of easy connection and short circuit of solder paste, large welding voids, low production yield, etc., to reduce processing costs and high welding yield. , the effect of low cost of solder balls

Active Publication Date: 2022-03-29
无锡光磊电子科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The pads on the surface of the chip are made of pure gold with a thickness of 1.2 microns, and the cost is high; solder paste or brushing of solder paste is required during the soldering process, the process is complicated, and the solder paste between the pads is easy to connect and short circuit, and the production yield is low; the second is The chip pad is made of gold-tin alloy. During the solid crystal process, flux is coated on the pad of the PCB board. After high temperature, the flux volatilizes, and the gold-tin alloy connects the LED chip and the PCB board.
The thickness of gold-tin alloy is generally more than 4um, and the cost is high; the thickness of gold-tin alloy is only 4um, and the amount of welding metal is small, which is prone to virtual soldering, desoldering, large soldering voids, and low yield

Method used

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  • Preparation method of pad for flip-chip led chip

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] This embodiment provides a method for preparing flip-chip LED chip pads, including the following steps:

[0021] S1: Open the electrode of the flip-chip LED wafer chip to expose the gold electrode of the previous layer of the flip-chip LED wafer chip;

[0022] S2: Fix the grid plate on the flip-chip LED wafer chip in step S1, the grid on the grid plate is aligned with the flip-chip LED wafer chip;

[0023] S3: Fill the tin paste into the grid to cover the flip-chip LED wafer chip;

[0024] S4: heating and melting the tin paste, bonding the gold electrode in step S1 to form a tin pad, keeping the grid plate fixed on the flip-chip LED wafer chip during the heating process, and not removing the grid plate during the heating process, It is beneficial to ensure the size consistency of solder balls;

[0025] S5: Remove the grid plate to obtain flip-chip LED chip bonding pads.

[0026] In this embodiment, the preparation material of the grid plate in step S2 is a high tempe...

Embodiment 2

[0031] This embodiment provides a method for preparing flip-chip LED chip pads, including the following steps:

[0032] S1: Open the electrode of the flip-chip LED wafer chip to expose the gold electrode of the previous layer of the flip-chip LED wafer chip;

[0033] S2: Fix the grid plate on the flip-chip LED wafer chip in step S1, the grid on the grid plate is aligned with the flip-chip LED wafer chip;

[0034] S3: Fill the tin paste into the grid to cover the flip-chip LED wafer chip;

[0035] S4: heating and melting the tin paste, bonding the gold electrode in step S1 to form a tin pad, keeping the grid plate fixed on the flip-chip LED wafer chip during the heating process, and not removing the grid plate during the heating process, It is beneficial to ensure the size consistency of solder balls;

[0036] S5: Remove the grid plate to obtain flip-chip LED chip bonding pads.

[0037] In this embodiment, the preparation material of the grid plate in step S2 is high tempera...

Embodiment 3

[0042] This embodiment provides a method for preparing flip-chip LED chip pads, including the following steps:

[0043] S1: Open the electrode of the flip-chip LED wafer chip to expose the gold electrode of the previous layer of the flip-chip LED wafer chip;

[0044] S2: Fix the grid plate on the flip-chip LED wafer chip in step S1, the grid on the grid plate is aligned with the flip-chip LED wafer chip;

[0045] S3: Fill the tin paste into the grid to cover the flip-chip LED wafer chip;

[0046] S4: heating and melting the tin paste, bonding the gold electrode in step S1 to form a tin pad, keeping the grid plate fixed on the flip-chip LED wafer chip during the heating process, and not removing the grid plate during the heating process, It is beneficial to ensure the size consistency of solder balls;

[0047] S5: Remove the grid plate to obtain the flip-chip LED chip bonding pad.

[0048] In this embodiment, the preparation material of the grid plate in step S2 is stainless...

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Abstract

The invention belongs to the technical field of semiconductors, and in particular relates to a preparation method of a flip-chip LED chip pad. The invention provides a flip-chip LED chip pad, a flip-chip LED wafer chip and a metal layer; the metal layer is a tin layer, and the tin layer has a spherical structure and is wrapped and attached to the flip-chip LED wafer chip. The method for preparing a flip-chip LED chip pad provided by the present invention uses a grid plate to replace gold-tin alloy with pure tin. When mounting and using, it does not need the steps of applying solder paste or brushing solder paste in the solid crystal process, and melting tin at high temperature to form The cost of balls and tin balls is low, the thickness of 4 microns can be made, the welding metal raw materials are sufficient, the welding yield is high, the processing cost of the whole process is reduced, and the processing efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a preparation method of flip-chip LED chip pads. Background technique [0002] LED (Light Emitting Diode, Light Emitting Diode) is a solid-state semiconductor device capable of converting electrical energy into visible light, which can directly convert electrical energy into light energy. As a new type of lighting source material, it is widely used in various fields. Due to the problems of poor heat dissipation, uneven current distribution of transparent electrodes, and light blocking of surface electrode pads and leads in traditional formal LEDs, more and more manufacturers and engineers are committed to seeking new technologies for preparing LED chips, and flip chip technology has come into play. And born. [0003] Compared with regular LED chips, flip-chip LED chips can solve the problem of heat dissipation. Flip-chip LED chips have the advantages of lower...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L33/00H01L33/48H01L33/62
CPCH01L33/62H01L33/005H01L33/48
Inventor 唐红祥
Owner 无锡光磊电子科技有限公司