US-12626834-B2 - Conductive paste and electronic device

US12626834B2US 12626834 B2US12626834 B2US 12626834B2US-12626834-B2

Abstract

The present application provides a conductive paste and an electronic device and relates to a technical field of new material. The conductive paste provided by the present application includes, 5%-20% by weight of a resin, 5%-20% by weight of a solvent, and 70%-90% by weight of a conductive filler; the conductive filler includes a first conductive filler, a second conductive filler, and a third conductive filler, and the first conductive filler is configured to increase a filling amount of the conductive filler, the second conductive filler is configured to reduce a sintering temperature of the conductive filler, and the third conductive filler is configured to slow erosion to the conductive filler by a soldering tin during a soldering process. By adopting the technical solution of the present application, soldering can be performed directly with soldering tin wire.

Inventors

Zhongwei REN
Jiameng KANG

Assignees

BEIJING DREAM INK TECHNOLOGIES CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20211123
Priority Date: 20210324

Claims (4)

1 . A conductive paste, comprising: 5%-20% by weight percentage of a resin, 5%-20% by weight percentage of a solvent, and 70%-90% by weight percentage of a conductive filler; wherein the conductive filler comprises a first conductive filler, a second conductive filler, and a third conductive filler, wherein the first conductive filler is flake silver powder, and a specific surface area of the flake silver powder is equal to or smaller than 0.35 m 2 /g, wherein the second conductive filler is spherical silver powder, and a particle size of the spherical silver powder is equal to or smaller than 600 nm, wherein the third conductive filler is flake silver coating copper powder, which has a single crystal structure and a thickness-to-diameter ratio greater than 1:10, and wherein a weight percentage of the flake silver powder to the spherical silver powder and the flake silver coating copper powder is 40:26:10, 50:10:16, 55:9:9, or 65:5:10.
2 . The conductive paste according to claim 1 , wherein the resin is one or more of a polyester resin, an epoxy resin and an acrylic resin.
3 . An electronic device, comprising a substrate and a conductive wiring on the substrate, wherein the conductive wiring is made of a conductive paste of claim 1 .
4 . The electronic device according to claim 3 , further comprising an electronic component soldered to the conductive wiring by a soldering tin layer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a U.S. National Phase of International Application No. PCT/CN2021/132435, entitled “CONDUCTIVE PASTE AND ELECTRONIC DEVICE,” and filed on Nov. 23, 2021. International Application No. PCT/CN2021/132435 claims priority to Chinese Patent application No. 202110311458.9 filed on Mar. 24, 2021. The entire contents of each of the above-listed applications are hereby incorporated by reference for all purposes. TECHNICAL FIELD The present application relates to the field of new material, in particular to a conductive paste and an electronic device. BACKGROUND A copper layer on top layer of a conventional printed circuit board is susceptible to oxidation, thereby inhibiting the wetting effect of the soldering tin paste, which prevents the copper layer from creating reliable solder joints and increases a detachment risk of electrical component assembly. While the disadvantage of a copper layer being susceptible to oxidation may be overcome by electroplating or chemical-plating methods in which the nickel or gold layer is plated to improve the soldering reliability, the process is complicated and the environment may be contaminated. In prior art, there are also technical solutions for fabricating printed circuit boards with low temperature cured conductive paste instead of copper, however, low temperature cured conductive pastes in prior art also fail to achieve direct soldering of soldering tin wire, therefore, it is desirable to develop a conductive paste that can be soldered directly with soldering tin wire. SUMMARY The present application provides a conductive paste and an electronic device, which can be directly soldered by soldering tin wire. In a first aspect, the present application provides a conductive paste, which adopts following technical solutions: A conductive paste, comprises 5%-20% by weight percentage of a resin, 5%-20% by weight percentage of a solvent, and 70%-90% by weight percentage of a conductive filler; wherein the conductive filler comprises a first conductive filler, a second conductive filler, and a third conductive filler, wherein the first conductive filler is configured to increase a filling amount of the conductive filler, the second conductive filler is configured to reduce a sintering temperature of the conductive filler, and the third conductive filler is configured to slow corrosion to the conductive filler by solder during soldering. Optionally, a filling upper limit of the first conductive filler is higher than 90%. Optionally, the second conductive filler has a sintering temperature below 150° C. Optionally, a velocity v1 of alloying the first conductive filler with tin, a velocity v2 of alloying the second conductive filler with tin, and a velocity v3 of alloying the third conductive filler with tin satisfy: v3<v1, v3<v2. Optionally, the first conductive filler is flake silver powder, the second conductive filler is spherical silver powder, and the third conductive filler is flake silver coating copper powder. Optionally, a specific surface area of the flake silver powder is equal to or smaller than 0.35 m2/g, a particle size of the spherical silver powder is equal to or smaller than 600 nm, the flake silver coating copper powder has a single crystal structure, and a thickness-to-diameter ratio is greater than 1:10. Optionally, a weight percentage of the flake silver powder is higher than 50% and a weight percentage of the flake silver coating copper powder is higher than 10%. Optionally, the resin is one or more of a polyester resin, an epoxy resin and an acrylic resin. In a second aspect, the present application provides an electronic device, comprising a substrate and a conductive wiring on the substrate, wherein the conductive wiring is made of the conductive paste according to any one of the above items. Optionally, the electronic device further comprises an electronic component soldered to the conductive wiring by a soldering tin layer. A conductive paste and an electronic device are provided. In the conductive paste, the conductive filler includes a first conductive filler, a second conductive filler and a third conductive filler, and the first conductive filler can be used to increase the filling amount of the conductive filler, such that the conductive paste has better electrical properties; the second conductive filler can be used to reduce a sintering temperature of the conductive filler, making the conductive paste easier to be soldered and sintered; the third conductive filler can be used to slow corrosion to the conductive filler by the soldering tin during the soldering process, such that the conductive wiring can be soldered directly through the soldering tin wire without significantly affecting the performance of the conductive wiring. BRIEF DESCRIPTION OF DRAWINGS In order to more clearly explain some embodiments of the present application or the technical solution in the related art, the drawing