Welding method of demetallized ceramic substrate having surface capillary microgroove structure

Patent metadata

Field	Value
Publication number	US-12009270-B2
Application number	US-201917607901-A
Country	US
Kind code	B2
Filing date	Nov 14, 2019
Priority date	Apr 30, 2019
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

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.

First claim

What is claimed is:

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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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 Al 2 O 3 , BeO and AlN.

7. 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.

8. 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.

9. 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.

Assignees

• Univ South China Tech
• Guangdong Luckystar Electronic Tech Co Ltd
• Shenzhen Good Machine Automatic Equipment Co Ltd

Inventors

• Li Zongtao
• Tang Yong
• Wang Hong
• Yu Shudong
• Wu Kejian
• Liang Guanwei
• Ding Xinrui

Classifications

• H10W70/692

  Ceramics or glasses · CPC title

• H10W70/093

  Connecting or disconnecting other interconnections thereto or therefrom, e.g. connecting bond wires or bumps · CPC title

• H10W70/60

  Insulating or insulated package substrates; Interposers; Redistribution layers (leadframes H10W70/40) · CPC title

• H10W70/657

  on sidewalls or bottom surfaces of the package substrates, interposers or redistribution layers · CPC title

• H10W70/68 Primary

  Shapes or dispositions thereof · CPC title