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CN-122000115-A - Low-temperature curing conductive paste, preparation method thereof and filling method of glass through holes

CN122000115ACN 122000115 ACN122000115 ACN 122000115ACN-122000115-A

Abstract

The invention provides a low-temperature curing conductive paste, a preparation method thereof and a filling method of a glass through hole, and belongs to the technical field of electronic packaging materials. The invention adopts silver-coated copper powder to isolate oxygen through a silver layer, not only retains the low cost advantage of copper, but also has conductivity and oxidation resistance close to silver, and obviously reduces the material cost while ensuring the conductivity, and adopts a bisphenol A epoxy resin and alicyclic epoxy resin composite system, and an anhydride curing agent and phenolic resin curing system to realize low-temperature curing, thereby avoiding thermal stress cracking of a glass substrate caused by high-temperature sintering, and adopts an epoxy silane coupling agent and an aminosilane coupling agent to obviously promote interface bonding.

Inventors

  • LI JUNPENG
  • ZHANG ZHENGFU
  • GAO JIQIANG
  • ZHU JUNYU
  • LI WEI
  • LI JIANGHUI
  • Chen Kaicha

Assignees

  • 贵研电子材料(云南)有限公司

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. The low-temperature curing conductive paste comprises, by mass, 75-90% of a conductive phase, 5-15% of a resin binding phase, 2-6% of a curing agent, 0.3-1.5% of a curing accelerator, 0.5-2.0% of a coupling agent, 0.1-0.8% of a leveling agent and 0.05-0.3% of a defoaming agent; the conductive phase is silver-coated copper powder; the resin binding phase is bisphenol A epoxy resin and alicyclic epoxy resin; the curing agent is anhydride curing agent and phenolic resin; The coupling agent is epoxy silane coupling agent and amino silane coupling agent.
  2. 2. The low-temperature curing conductive paste according to claim 1, wherein the average particle diameter of copper cores in the silver-coated copper powder is 2.0-5.0 μm, the coating thickness of the silver layer is 50-200 nm, and the mass fraction of silver is 15-25%.
  3. 3. The low-temperature-curable conductive paste according to claim 1, wherein the mass ratio of bisphenol a type epoxy resin to alicyclic epoxy resin is (60-80): 20-40.
  4. 4. The low-temperature-curable conductive paste according to claim 1, wherein the acid anhydride curing agent is at least one of methyl tetrahydrophthalic anhydride and methyl hexahydrophthalic anhydride, and the phenolic resin is novolac epoxy resin.
  5. 5. The low-temperature curing conductive paste according to claim 1, wherein the mass ratio of the acid anhydride curing agent to the phenolic resin is (70-85): (15-30).
  6. 6. The low-temperature curing conductive paste according to claim 1, wherein the mass ratio of the epoxy silane coupling agent to the aminosilane coupling agent is (1-3): 1.
  7. 7. The method for preparing the low-temperature curing conductive paste according to any one of claims 1 to 6, comprising the following steps: (1) Mixing a resin binding phase, a curing agent and a curing accelerator to obtain a resin system; (2) And (3) mixing the resin system obtained in the step (1), a coupling agent, a leveling agent, a defoaming agent and a conductive phase to obtain the low-temperature curing conductive paste.
  8. 8. A method of filling a glass via, comprising the steps of: filling the low-temperature curing conductive paste according to any one of claims 1 to 6 into the glass through hole, and then curing.
  9. 9. The filling method according to claim 8, wherein the glass via hole has a pore diameter of 20 to 100 μm and an aspect ratio of (3 to 10): 1.
  10. 10. The filling method according to claim 8, wherein the curing temperature is 150-170 ℃.

Description

Low-temperature curing conductive paste, preparation method thereof and filling method of glass through holes Technical Field The invention belongs to the technical field of electronic packaging materials, and particularly relates to a low-temperature curing conductive paste, a preparation method thereof and a filling method of a glass through hole. Background As semiconductor packages move toward higher density, miniaturization, and versatility, conventional organic substrates and silicon intermediaries face challenges in high frequency signal transmission, thermal management, and cost control. The glass substrate is a key material for advanced packaging of the next generation due to its excellent dielectric properties (dielectric constant 3.7-4.5, loss factor < 0.001), high flatness (warpage <10 μm), adjustable coefficient of thermal expansion (CTE 3-9 ppm/° C) and low cost advantages. The glass through-hole (TGV) technology has become a core process of a glass interposer by preparing micron-sized vertical interconnect channels on a glass substrate to achieve high-density electrical connection between a chip and a carrier. The TGV filling material needs to meet multiple requirements of conductivity, filling property, interface binding force, reliability and the like. The current mainstream filling technology is conductive paste filling, which has the advantages of simple process, low cost and suitability for mass production, but faces the following technical bottlenecks: (1) The conductivity and the cost are balanced, the resistivity of the pure silver paste can be as low as 10 -5 Ω & cm, but the price of silver is high (800 dollars/kg), the cost of the copper paste is low but the copper paste is easy to oxidize, and the resistivity of the copper paste is rapidly increased to more than 10 -3 Ω & cm after sintering in air. (2) The combination of low temperature curing and interface is that the softening point of the glass substrate is 550-700 ℃ and the glass substrate cannot bear the high temperature sintering (> 500 ℃) of the traditional silver paste. Epoxy resin-based low-temperature curing systems (80-200 ℃) are the mainstream choice, but common epoxy resins have weak interfacial bonding force with glass (peel strength < 2N/cm), and the curing shrinkage causes the top of the through hole to be concave, and an additional CMP (chemical mechanical polishing) process is needed. Therefore, how to improve the conductive paste to have high conductivity, low-temperature curing and strong interfacial bonding force is a technical problem to be solved in the art. Disclosure of Invention The invention aims to provide low-temperature curing conductive paste, a preparation method thereof and a filling method of glass through holes. The low-temperature curing conductive paste provided by the invention has high conductivity, low-temperature curing and strong interface binding force, and can realize efficient and reliable filling of the glass through holes. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a low-temperature curing conductive paste which comprises, by mass, 75-90% of a conductive phase, 5-15% of a resin binding phase, 2-6% of a curing agent, 0.3-1.5% of a curing accelerator, 0.5-2.0% of a coupling agent, 0.1-0.8% of a leveling agent and 0.05-0.3% of a defoaming agent; the conductive phase is silver-coated copper powder; the resin binding phase is bisphenol A epoxy resin and alicyclic epoxy resin; the curing agent is anhydride curing agent and phenolic resin; The coupling agent is epoxy silane coupling agent and amino silane coupling agent. Preferably, the average particle size of copper cores in the silver-coated copper powder is 2.0-5.0 mu m, the coating thickness of the silver layer is 50-200 nm, and the mass fraction of silver is 15-25%. Preferably, the mass ratio of the bisphenol A epoxy resin to the alicyclic epoxy resin is (60-80): 20-40. Preferably, the anhydride curing agent is at least one of methyl tetrahydrophthalic anhydride and methyl hexahydrophthalic anhydride, and the phenolic resin is novolac epoxy resin. Preferably, the mass ratio of the anhydride curing agent to the phenolic resin is (70-85) to (15-30). Preferably, the mass ratio of the epoxy silane coupling agent to the amino silane coupling agent is (1-3): 1. The invention also provides a preparation method of the low-temperature curing conductive paste, which comprises the following steps: (1) Mixing a resin binding phase, a curing agent and a curing accelerator to obtain a resin system; (2) And (3) mixing the resin system obtained in the step (1), a coupling agent, a leveling agent, a defoaming agent and a conductive phase to obtain the low-temperature curing conductive paste. The invention provides a filling method of a glass through hole, which comprises the following steps: Filling the low-temperature curing conductive paste in the technical scheme into