Low-temperature sintered hybrid conductive silver paste for chip package and preparation method thereof

A technology of conductive silver paste and low-temperature sintering, which is applied in the manufacture of cables/conductors, conductive materials dispersed in non-conductive inorganic materials, circuits, etc., and can solve the problem of uneven mixing of submicron silver, difficulty in electrolysis, and loss of double layer dispersion Advantages and other issues, to achieve the effect of excellent mechanical and electrical properties

Active Publication Date: 2017-09-29
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, because in the process of preparing the mixed conductive silver paste, it is necessary to add binders and some other organic additives to achieve good sintering performance, and these binders and organic additives must be dissolved in organic solvents, which is this type The dispersant is difficult to electrolyze in the organic solvent, and loses the dispersion advantage of the electric double layer, so that the nano-silver particles coated with the ionic dispersant are easy to aggregate and settle in the organic solvent, the dispersibility is poor, and the occurrence of micron silver particles , Inhomogeneous mixing of submicron silver
Therefore, the application of this type of ionic dispersant in the preparation of micron, submicron and nanometer mixed silver paste is limited

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] Flake micron silver powder with a size of 6 μm and a thickness of 250 nm, spherical submicron silver powder with a size of 500 nm and synthetically prepared spherical nano silver powder with a thickness of 10 nm are mixed, and the mixing mass ratio is 2:1:2.

[0041] The synthetic method of nano-silver is that the mixed solution of 440g / L sodium citrate solution and 280g / L ferrous sulfate solution is added dropwise in the silver nitrate solution of 84g / L, react 30min at room temperature, sodium citrate solution, ferrous sulfate solution The volume ratio of the iron solution to the silver nitrate solution is 7:5:5. After the reaction is completed, use a centrifuge to separate it and wash it repeatedly with deionized water for at least 3 times to synthesize silver nanoparticles with sodium citrate as a dispersant. .

[0042] The method of surface modification of flake micron silver powder and spherical submicron silver powder is to configure an ethanol solution of citric ...

Embodiment 2

[0053] In Example 2, flaky micron silver powder with a particle size of 6 μm and a thickness of 250 nm, spherical submicron silver powder with a particle size of 500 nm, and synthetically prepared spherical nano silver powder of 10 nm were used for mixing, and the mixing ratio was 2:1:2. The synthetic method of nano-silver is that the mixed solution of 440g / L sodium citrate solution and 280g / L ferrous sulfate solution is added dropwise in the silver nitrate solution of 84g / L, react 30min at room temperature, sodium citrate solution, ferrous sulfate solution The volume ratio of the iron solution to the silver nitrate solution is 7:5:5. After the reaction is completed, use a centrifuge to separate it and wash it repeatedly with deionized water for at least 3 times to synthesize silver nanoparticles with sodium citrate as a dispersant. .

[0054] The method of surface modification of flake micron silver powder and spherical submicron silver powder is to configure an ethanol solut...

Embodiment 3

[0059] In Example 3, flaky micron silver powder with a particle size of 6 μm and a thickness of 250 nm, spherical submicron silver powder with a particle size of 500 nm, and synthetically prepared spherical nano silver powder of 10 nm were used for mixing, and the mixing ratio was 2:1:2. The synthetic method of nano-silver is that the mixed solution of 440g / L sodium citrate solution and 280g / L ferrous sulfate solution is added dropwise in the silver nitrate solution of 84g / L, react 30min at room temperature, sodium citrate solution, ferrous sulfate solution The volume ratio of the iron solution to the silver nitrate solution is 7:5:5. After the reaction is completed, use a centrifuge to separate it and wash it repeatedly with deionized water for at least 3 times to synthesize silver nanoparticles with sodium citrate as a dispersant. .

[0060] The method of surface modification of flake micron silver powder and spherical submicron silver powder is to configure an ethanol solut...

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Abstract

The invention discloses low-temperature sintered hybrid conductive silver paste for chip package and a preparation method thereof. The low-temperature sintered hybrid conductive silver paste comprises 50-95wt% of conductive silver powders and 5-50wt% of organic carrier. The conductive silver powders contain 20-60wt% of micrometer-scale flake silver powders, 5-40wt% of submicron-scale spherical silver powders and 20-60 wt% of nano-scale spherical silver powders. The organic carrier contains 3 to 30 wt% of binder, 40 to 97.9 wt% of solvent and 0.01 to 30 wt% of other additives. The surface modification of the micron-scale silver powders and the submicron-scale silver powders can adapt the decomposition temperature of a modified surface dispersant to that of a water-based ionic dispersant of such type, so as to realize the low-temperature sintering of hybrid silver paste.

Description

technical field [0001] The invention relates to a conductive silver paste, in particular to a low-temperature sintering mixed conductive silver paste for chip packaging and a preparation method thereof, which is especially suitable for high-power chip packaging and the formation of conductive circuits; it belongs to the field of electronic packaging materials. Background technique [0002] In recent years, with the continuous expansion of the application of high-power semiconductor components, higher requirements have been put forward for electronic packaging and interconnection materials. High-power chips, such as silicon carbide and gallium nitride, have high operating temperatures and high current densities, which means that interconnect materials are required to withstand operating temperatures exceeding 200°C and high current densities. Under such conditions of use, neither the traditional tin-lead solder nor lead-free solder in the field of electronic packaging can mee...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01B1/22H01B13/00
CPCH01B1/22H01B13/00
Inventor 张新平金虹周敏波
Owner SOUTH CHINA UNIV OF TECH
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