CN-120264981-B - Mini LED lamp bead and packaging method thereof

CN120264981BCN 120264981 BCN120264981 BCN 120264981BCN-120264981-B

Abstract

The invention discloses a Mini LED lamp bead and a packaging method thereof, which relate to the technical field of LED lamp beads, wherein the packaging method comprises the steps of adopting mixed gas to perform plasma cleaning on a copper foil plate with preset thickness; the manufacturing method comprises the steps of forming nano-imprinting glue on a copper foil plate, carrying out nano-imprinting on the surface of the copper foil plate according to the type of a P/N electrode pad in an LED chip to form a nano-imprinting pattern, etching the copper foil plate to manufacture a first pad, printing tin paste on the pad through a nano steel mesh, fixing the LED chip on the first pad, carrying out nitrogen-filled reflow soldering to fix the LED chip and the first pad, coating photoresist on the back of the copper foil plate, exposing and etching to form a circuit pattern, removing the photoresist on the back of the copper foil plate, printing a solder resist layer on the back of the copper foil plate, and windowing to form a second pad, wherein the copper foil plate is used for replacing a substrate in the prior art, and the cost of manufacturing the LED lamp beads can be greatly reduced by utilizing the characteristics of low cost of the copper foil plate.

Inventors

JIANG CHUNMIN
HU LIBIN
LAN YI

Assignees

江西蓝科半导体有限公司

Dates

Publication Date: 20260505
Application Date: 20250429

Claims (7)

1. The packaging method of the Mini LED lamp bead is characterized by comprising the following steps of: acquiring a copper foil plate with a preset thickness; performing plasma cleaning on the copper foil plate by adopting mixed gas with a preset proportion to remove oxides on the surface of the copper foil plate, wherein the mixed gas comprises nitrogen and hydrogen with the preset proportion; Forming nano-imprinting glue with high cations on the copper foil plate, and carrying out nano-imprinting on the surface of the copper foil plate according to the type of a P/N electrode pad in the LED chip to form a corresponding nano-imprinting pattern; Etching the copper foil plate by adopting an etching technology to manufacture a first bonding pad; printing solder paste on the bonding pad through a nano steel mesh, and fixing the LED chip on the first bonding pad by adopting a die bonding process; through nitrogen-filled reflow soldering, the LED chip and the first bonding pad are fixedly connected; coating photoresist on the back of the copper foil plate, and exposing and etching according to the corresponding patterns to form a circuit pattern connected with the first bonding pad; Removing photoresist on the back of the copper foil plate; Printing a solder mask layer according to the surface range of the back surface of the copper foil plate, and windowing the solder mask layer according to the circuit pattern to form a second bonding pad connected with part of the circuit pattern; cutting the copper foil plate by adopting cutting equipment to prepare LED lamp beads with preset sizes; before the step of adopting the mixed gas with the preset proportion to carry out plasma cleaning on the copper foil plate, the method further comprises the following steps of; Engraving on a copper foil plate with preset thickness by adopting engraving equipment so as to form positioning holes and preset mark points on the copper foil plate; the thickness of the copper foil plate is 15-50 um; After the step of passing through the furnace through nitrogen-filled reflow soldering to fixedly connect the LED chip and the bonding pad, the method further comprises the following steps: Prefabricating a semi-cured film; Carrying out plasma cleaning on the copper foil plate subjected to die bonding, and carrying out hot pressing on the semi-solidified film on the copper foil plate by adopting a vacuum hot pressing technology; and fixing the semi-solidified film by adopting high-temperature baking.
2. The method of packaging Mini LED lamp beads according to claim 1, wherein in the step of plasma cleaning the copper foil plate subjected to die bonding, The gas adopted in the plasma cleaning is one of oxygen, argon and nitrogen.
3. The method of packaging Mini LED lamp beads according to claim 2, wherein, in the step of plasma cleaning the copper foil plate after the die bonding, The plasma gas adopts argon, the flow rate of the gas is 120sccm, the power of a radio frequency power supply is 250w, the vacuum degree is 30Pa, and the cleaning time is 120 seconds.
4. The method for packaging Mini LED lamp beads according to claim 1, wherein in the step of plasma cleaning the copper foil plate by using a mixed gas with a preset ratio, The mixed gas is 95% nitrogen and 5% hydrogen, the flow rate of the mixed gas is 100sccm, the power of a radio frequency power supply is 280w, the vacuum degree is 30Pa, and the cleaning time is 180 seconds.
5. A Mini LED lamp bead prepared by the encapsulation method of the Mini LED lamp bead according to any one of the preceding claims 1-4, the Mini LED lamp bead comprising a copper foil plate having a first side and a second side, a first bonding pad, an LED chip, a solder mask having a second bonding pad, and a circuit pattern provided on the second side; The LED chip is arranged on the first side part through the first bonding pad, the solder mask layer is laminated under the second side part, and the second bonding pad is arranged opposite to part of the circuit pattern; The circuit patterns are used for connecting the first bonding pads with the second bonding pads, and the first side parts and the second side parts are arranged oppositely.
6. The Mini LED light bead of claim 5, wherein the first bonding pad comprises a first red bonding pad, a first green bonding pad, and a first blue bonding pad, the LED chip comprising a red light chip, a green light chip, and a blue light chip; The red light chip is connected with the first red light bonding pad, the green light chip is connected with the first green light bonding pad, and the blue light chip is connected with the first blue light bonding pad.
7. The Mini LED lamp bead of claim 6, wherein the circuit pattern comprises a red sub-circuit, a green sub-circuit, a blue sub-circuit, and a co-polar sub-circuit; the red light sub-circuit, the green light sub-circuit and the blue light sub-circuit are respectively connected with the first end of the red light chip, the first end of the green light chip and the first end of the blue light chip; The common electrode sub-circuit is used for being commonly connected with the second end of the red light chip, the second end of the green light chip and the second end of the blue light chip; the second bonding pad comprises a second red bonding pad, a second green bonding pad, a second blue bonding pad and a common electrode bonding pad; the second red light bonding pad, the second green light bonding pad, the second blue light bonding pad and the common electrode bonding pad are respectively connected with the part of the red light sub-circuit, the part of the green light sub-circuit, the part of the blue light sub-circuit and the part of the common electrode sub-circuit.

Description

Mini LED lamp bead and packaging method thereof Technical Field The invention relates to the technical field of LED lamp beads, in particular to a Mini LED lamp bead and a packaging method thereof. Background With the rapid development of the LED technology, mini LEDs are widely applied to the display field due to the advantages of high brightness, low power consumption, high contrast ratio and the like. In the conventional process of manufacturing Mini LED lamp beads, a substrate with a circuit is required to be manufactured firstly, and then an inverted LED chip is fixedly crystallized on the substrate, however, the existing substrate has the problem of high cost, the prior substrate with the circuit is low in efficiency, and the problem of insufficient packaging density exists when the LED lamp beads are fixedly crystallized on the substrate. Disclosure of Invention Based on the above, the invention aims to provide a Mini LED lamp bead and a packaging method thereof, which are used for solving at least one technical problems of low efficiency, high cost and insufficient packaging density of the existing LED lamp bead die bonding on a substrate. The invention provides a method for packaging Mini LED lamp beads, which comprises the following steps: acquiring a copper foil plate with a preset thickness; performing plasma cleaning on the copper foil plate by adopting mixed gas with a preset proportion to remove oxides on the surface of the copper foil plate, wherein the mixed gas comprises nitrogen and hydrogen with the preset proportion; Forming nano-imprinting glue with high cations on the copper foil plate, and carrying out nano-imprinting on the surface of the copper foil plate according to the type of a P/N electrode pad in the LED chip to form a corresponding nano-imprinting pattern; Etching the copper foil plate by adopting an etching technology to manufacture a first bonding pad; printing solder paste on the bonding pad through a nano steel mesh, and fixing the LED chip on the first bonding pad by adopting a die bonding process; through nitrogen-filled reflow soldering, the LED chip and the first bonding pad are fixedly connected; coating photoresist on the back of the copper foil plate, and exposing and etching according to the corresponding patterns to form a circuit pattern connected with the first bonding pad; Removing photoresist on the back of the copper foil plate; Printing a solder mask layer according to the surface range of the back surface of the copper foil plate, and windowing the solder mask layer according to the circuit pattern to form a second bonding pad connected with part of the circuit pattern; And cutting the copper foil plate by adopting cutting equipment to prepare the LED lamp beads with preset sizes. Further, before the step of performing plasma cleaning on the copper foil plate by adopting the mixed gas with a preset proportion, the method further comprises the following steps; engraving is carried out on the copper foil plate with the preset thickness by adopting engraving equipment so as to form positioning holes and preset mark points on the copper foil plate. Further, the thickness of the copper foil plate is 15-50 um. Further, after the step of reflow soldering through nitrogen filling through the furnace to fixedly connect the LED chip and the bonding pad, the method further comprises: Prefabricating a semi-cured film; Carrying out plasma cleaning on the copper foil plate subjected to die bonding, and carrying out hot pressing on the semi-solidified film on the copper foil plate by adopting a vacuum hot pressing technology; and fixing the semi-solidified film by adopting high-temperature baking. Further, in the step of subjecting the copper foil plate subjected to the die bonding to plasma cleaning, The gas adopted in the plasma cleaning is one of oxygen, argon and nitrogen. Further, in the step of subjecting the copper foil plate subjected to the die bonding to plasma cleaning, The plasma gas adopts argon, the flow rate of the gas is 120sccm, the power of a radio frequency power supply is 250w, the vacuum degree is 30Pa, and the cleaning time is 120 seconds. Further, in the step of plasma cleaning the copper foil plate by adopting the mixed gas with a preset proportion, The mixed gas is 95% nitrogen and 5% hydrogen, the flow rate of the mixed gas is 100sccm, the power of a radio frequency power supply is 280w, the vacuum degree is 30Pa, and the cleaning time is 180 seconds. The invention further provides a Mini LED lamp bead, which is prepared by the packaging method of the Mini LED lamp bead, wherein the Mini LED lamp bead comprises a copper foil plate with a first side part and a second side part, a first bonding pad, an LED chip, a solder mask with a second bonding pad and a circuit pattern arranged on the second side part; The LED chip is arranged on the first side part through the first bonding pad, the solder mask layer is laminated under the second side part,