# US 12,009,270 B2 · Welding method of demetallized ceramic substrate having surface capillary microgroove structure

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- Number: US 12,009,270 B2
- Document ID: US12009270B2
- Status: Granted
- Kind: B2
- Application number: 17/607,901
- Filed: 2019-11-14
- Published: 2022-09-15
- Granted: 2024-06-11
- Earliest claimed: 2019-04-30
- Assignees: South China University of Technology; Guangdong Luckystar Electronic Technology Co., Ltd; Shenzhen Good-Machine Automatic Equipment Co., Ltd
- Applicants: South China University of Technology; Guangdong Luckystar Electronic Technology Co., Ltd; Shenzhen Good-Machine Automatic Equipment Co., Ltd
- Inventors: Zongtao Li; Yong Tang; Hong Wang; Shudong Yu; Kejian Wu; Guanwei Liang; Xinrui Ding
- Web page: https://patentgrep.com/patent/US12009270B2

## CPC

- H10W 70/68: Shapes or dispositions thereof
- H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls
- H10W 70/657: {on sidewalls or bottom surfaces of the package substrates, interposers or redistribution layers}
- H10W 70/692: Ceramics or glasses
- H10W 70/099: {Connecting interconnections to insulating or insulated package substrates, interposers or redistribution layers}
- H10W 70/60: Insulating or insulated package substrates; Interposers; Redistribution layers (leadframes H10W70/40)
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS

## Abstract

The present invention discloses a welding method of a demetallized ceramic substrate having a surface capillary microgroove structure. The demetallized ceramic substrate includes a ceramic substrate main body and surface capillary microstructures. The surface capillary microstructures are arranged on two lateral sides of the ceramic substrate main body and the surface capillary microstructures specifically are capillary microgrooves. The welding method includes the following steps: fixing a chip to an upper surface of the demetallized ceramic substrate having the surface capillary microgroove structure, fixing the ceramic substrate with the chip to a printed circuit board having a bonding pad, and placing melted solder on the bonding pad, and driving the solder to ascend to an electrode of the chip from the bonding pad in a lower layer by means of a capillary force, thereby realizing an electrical connection between the chip and the printed circuit board.

## Claims

### Claim 1

A welding method of a demetallized ceramic substrate having a surface capillary microgroove structure, the demetallized ceramic substrate comprising a ceramic substrate main body and surface capillary microstructures, the surface capillary microstructures being arranged on two lateral sides of the ceramic substrate main body and the surface capillary microstructures specifically being capillary microgrooves, the welding method comprises the following steps:
Step (1) fixing a chip to an upper surface of the demetallized ceramic substrate having the surface capillary microgroove structure;
Step (2) fixing the demetallized ceramic substrate with the chip to a printed circuit board having a bonding pad; and
Step (3) placing melted solder on the bonding pad, and driving the melted solder to ascend to an electrode of the chip from the bonding pad in a lower layer by means of a capillary force, thereby realizing an electrical connection between the chip and the printed circuit board.

### Claim 2 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein the surface capillary microstructures are two capillary microgrooves in mirror symmetry, the two capillary microgrooves being respectively formed in two lateral sides of the ceramic substrate main body and not being communicated with each other; and the capillary microgrooves are formed by etching the ceramic substrate main body inwards from an upper surface and from lateral side surfaces.

### Claim 3 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein the capillary microgrooves comprise rectangular microgrooves, zigzag microgrooves and round microgrooves.

### Claim 4 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein modes of preparing the capillary microgrooves comprise laser machining, photoetching and chemical etching.

### Claim 5 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein a mean width of the capillary microgrooves is 10-100 μm, and a mean groove depth thereof is 10-100 μm.

### Claim 6 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein a material of the ceramic substrate main body comprises Al2O3, BeO and AlN.

### Claim 7 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein the fixing in the step (1) comprises fixing by insulated glue.

### Claim 8 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein the fixing in the step (2) comprises fixing by insulated glue or mechanical clamping.

### Claim 9 (depends on 1)

The welding method of the demetallized ceramic substrate having the surface capillary microgroove structure according to claim 1, wherein the melted solder in the step (3) comprises a gold and tin eutectic solder, a melting point of the gold and tin eutectic solder being 217-230° C. and a gold content thereof being 10-15 wt %; and a welding mode comprises reflow soldering, an equipment power of the reflow soldering being 11-15 kW, a length of a heating zone being 1000-2000 mm and a heating temperature being 220-240° C.