Method for processing an ultra-high density space interconnect lead under light source guidance

Patent metadata

Field	Value
Publication number	US-11211357-B2
Application number	US-202017037909-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Jan 8, 2020
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A method for processing an ultra-high density interconnect wire under light source guidance, comprising preparing a photo-thermal response conductive paste, and putting it into an air pressure injector; driving the air pressure injector; the air pressure injector extrudes the photo-thermal response conductive paste, so that the photo-thermal response conductive paste is connected with the first chip to form an interconnection wire; stopping extruding the photo-thermal response conductive paste, and driving the air pressure injector to pull off the interconnection wire; a linear light source emits light and irradiates on the interconnection wire to bend to an upper side of a second chip bonding pad; an extrusion mechanism presses a free end of the interconnection wire on the second chip bonding pad; the first chip and the second chip are subjected to glue dripping encapsulation.

First claim

We claim:

1. A method for processing an ultra-high density interconnection wire under light source guidance, comprising the steps of:
S 1 : preparing a photo-thermal response conductive paste, and putting the photo-thermal response conductive paste into an air pressure injector;
S 2 : driving the air pressure injector, so that a micro-nozzle on the air pressure injector is aligned with a central position of a first chip bonding pad of a first chip; extruding, by the air pressure injector, the photo-thermal response conductive paste onto the first chip bonding pad; a surface of the photo-thermal response conductive paste is cured in air, so that the photo-thermal response conductive paste forms an interconnection wire and connects to the first chip;
S 3 : stopping extruding the photo-thermal response conductive paste, and driving the air pressure injector to pull off the interconnection wire;
S 4 : emitting light and irradiating, by a linear source, on the interconnection wire to bend a free end of the interconnection wire and bend to an upper side of a second chip bonding pad;
S 5 : pressing, by an extrusion mechanism, the free end of the interconnection wire on the second chip bonding pad, so that the interconnection wire connects the first chip and a second chip; and
S 6 : after the first chip and the second chip are connected, encapsulating the first chip and the second chip by dispensing glues on the first chip and the second chip.

2. The method for processing an ultra-high density interconnection wire under light source guidance according to claim 1 , wherein the photo-thermal response conductive paste includes the following components in parts by weight:

N-Isopropylacrylamide
40-50
parts;

N,N′-methylene bisacrylamide
5
parts;

2-hydroxy-2-methyl-1-phenyl-1-acetone
0.5
parts;

reduced graphene
0.3
parts;

eutectic gallium indium alloy
10
parts;

dimethyl sulfoxide
margin;

the purity of the eutectic gallium indium alloy is 99.99%.

3. The method for processing an ultra-high density interconnection wire under light source guidance according to claim 2 , wherein a preparation method of the photo-thermal response conductive paste includes the following steps:
Step A 1 : placing N-isopropylacrylamide, N, N′-methylene bisacrylamide and 2-hydroxy-2-methyl-1-phenyl-1-acetone in dimethyl sulfoxide according to a ratio, and carrying out ultrasonic dispersion for 5 min to obtain a precursor solution;
Step A 2 : adding the reduced graphene and the eutectic gallium indium alloy into a precursor solution according to a ratio, and performing ultrasonic dispersion for 10 min under a vacuum environment; wherein the purity of the eutectic gallium indium alloy is 99.99%;
Step A 3 : placing the solution in the Step A 2 in an ultraviolet light generator for reaction for 2 min to obtain the photo-thermal response conductive paste.

4. The method for processing an ultra-high density interconnection wire under light source guidance according to claim 2 , wherein the linear light source is connected with a continuous laser generator, and the wavelength of the light emitted by the continuous laser generator is 532 nm.

5. The method for processing an ultra-high density interconnect wire under light source guidance according to claim 1 , wherein the photo-thermal response conductive paste includes the following components in parts by weight:

3-(4-((4-methoxyphenyl)diazo)phenoxy)acrylate
9
parts;

diazo-1,2-bis(4,1-phenyl)diacrylate;
1
part;

azodiisobutyronitrile
1.2~1.8
parts;

eutectic gallium indium alloy
2
parts;

tetrahydrofuran
margin;

the purity of the eutectic gallium indium alloy is 99.99%.

6. The method for processing an ultra-high density interconnect wire under light source guidance according to claim 5 , wherein a manufacturing method of the photo-thermal response conductive paste includes the following steps:
Step B 1 : adding 3-(4-((4-methoxyphenyl) diazo) phenoxy) acrylate, diazo-1,2-bis (4, 1-phenyl) diacrylate and azobisisobutyronitrile into tetrahydrofuran according to a ratio, wherein a reaction temperature is 65° C., and a reaction time is 40˜60 h to obtain a precursor solution;
Step B 2 , drying the precursor solution into a dry matter, a drying temperature is 20° C., and a drying time is 12 h;
Step B 3 : mixing the eutectic gallium indium alloy with the dry matter according to a ratio, and carrying out vacuum ultrasonic dispersion for 10˜15 min to obtain the photo-thermal response conductive paste.

7. The method for processing an ultra-high density interconnect wire under light source guidance according to claim 5 , wherein the linear light source is connected with a continuous laser generator, and the wavelength of a light emitted by the continuous laser generator is 365 nm.

8. The method for processing an ultra-high density interconnection wire under light source guidance according to claim 1 , wherein the air pressure injector in the step S 3 is moved in the Y-axis direction, and a moving speed is 3˜10 mm/s.

9. The method for processing an ultra-high density interconnection wire under light source guidance according to claim 1 , wherein an irradiation time in the Step S 4 is 40 s˜60 s.

Assignees

• Univ Guangdong Technology

Inventors

• Chen Yun
• Ding Shuquan
• He Yunbo
• Hou Maoxiang
• Chen Xin
• Gao Jian
• Zhao Ni
• Zhang Lanyu
• Wang Zhengping

Classifications

• H10W90/753

  between laterally-adjacent chips · CPC title

• H10W72/07511

  Treating the bonding area before connecting, e.g. by applying flux or cleaning · CPC title

• H10W72/5366

  the bond wires having kinks · CPC title

• H10W72/01561

  Chemical or physical modification, e.g. by sintering or anodisation (patterning H10W72/01551) · CPC title

• H10W72/01551

  Changing the shapes of bond wires · CPC title