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KR-20260067110-A - Ag complex compound for die attach paste and method for preparing the same

KR20260067110AKR 20260067110 AKR20260067110 AKR 20260067110AKR-20260067110-A

Abstract

A silver complex for die attach paste and a method for manufacturing the same are disclosed, which are added to the die attach paste to improve low-temperature sintering, high electrical conductivity, and high thermal conductivity characteristics. According to the present invention, a silver complex for die attach prepared through a chemical reaction using ionic bonding can be added to a die attach paste to improve the semiconductor properties of the die attach paste. A silver complex for die attach paste according to the present invention may include a method for manufacturing a die attach paste comprising the steps of: dissolving a silver precursor in a solvent to prepare a silver precursor solution; dissolving an alkyl chain-based organic material in a solvent to ionize it; mixing the silver precursor solution with the ionized alkyl chain-based organic material to produce a silver complex; and purifying the silver complex to obtain a high-purity silver complex. The silver complex according to the present invention is added to the die attach paste to improve die adhesion strength and thermal conductivity characteristics. The silver complex according to the present invention is added to the die attach paste, and the die attach paste has the advantage of being able to be sintered at a low temperature of 200°C or lower.

Inventors

  • 김윤진
  • 김현준
  • 이윤재
  • 박지선

Assignees

  • 주식회사 테라온
  • 한국전자기술연구원

Dates

Publication Date
20260512
Application Date
20241105

Claims (10)

  1. A silver complex for die-attach paste formed by the ionic bonding of silver ions of a silver (Ag) precursor and ionized alkyl chain organic compounds.
  2. In paragraph 1, A silver complex for die attach paste, characterized in that the above silver precursor comprises one or more selected from the group consisting of silver acetate, silver nitrate, silver pentafluoropropionate, silver phosphate, and silver carbonate.
  3. In paragraph 1, A silver complex for die attach paste, characterized in that the above-mentioned ionized alkyl chain-based organic material comprises one or more selected from the group consisting of dodecylamine, oleylamine, oleic acid, octadecylamine, hexadecylamine, polyethylamine, hexanoic acid, decanoic acid, neodecanoic acid, ethylhexanoic acid, lauric acid, benzoic acid, and octadecanoic acid, which are ionized.
  4. In paragraph 3, A silver complex for die-attach paste, characterized in that the carbon number of the ionized alkyl chain-based organic compound is 10 to 12.
  5. In any one of paragraphs 1 through 4, A silver complex for die attach paste, characterized in that the molar ratio of the silver precursor to the ionized alkyl chain-based organic compound is 1:1 to 1:3.
  6. A die attach paste comprising a silver complex for the die attach paste of claim 5.
  7. A step of preparing a silver precursor solution by dissolving a silver precursor in a solvent; A step of dissolving an alkyl chain-based organic in a solvent to ionize it; and A method for preparing a silver complex for die attach paste, comprising the step of mixing a silver precursor solution with an ionized alkyl chain-based organic material to produce a silver complex.
  8. In Paragraph 7, A method for manufacturing a silver complex for die attach paste, characterized by additionally including a step of purifying the generated silver complex.
  9. In Paragraph 7, A method for manufacturing a die attach paste, characterized in that the solvent for dissolving the above silver precursor comprises one or more selected from the group consisting of toluene, hexane, xylene, benzene, cyclohexane, ethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, chloroform, purified water (DI-water), ethanol, methanol, and isopropyl alcohol.
  10. In Paragraph 7, A method for manufacturing a die attach paste, characterized in that the solvent for dissolving the above-mentioned alkyl chain-based organic material comprises one or more selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide ( RbOH ), cesium hydroxide (CsOH), calcium hydroxide (Ca(OH)₂), barium hydroxide (Ba(OH) ₂ ), and strontium hydroxide (Sr(OH) ₂ ).

Description

Silver complex compound for die attach paste and method for preparing the same The present invention relates to a silver complex containing silver ions in an organic substrate that can be used in die attach paste, and a method for manufacturing the same. Specifically, it relates to a silver complex in which silver (Ag) is ionicly bonded to an alkyl chain-based organic material that contributes to low-temperature sintering of the die attach paste, and a method for manufacturing the same. The individual squares that make up a semiconductor wafer are called dies. Semiconductor packages are fabricated by bonding dies to a substrate, DBC (direct bonding copper), and AMB (active metal brazing) using die attach paste. In this regard, semiconductor die attach materials must fundamentally possess high adhesion and high thermal conductivity, and must also be commercially processable and price-competitive. Silver paste is mainly used as a semiconductor die attach material. In order for silver paste to fully exhibit its properties as a die attach material, the silver paste must satisfy high sintering density characteristics after the heat treatment process, and the heat treatment temperature must be low. The higher the heat treatment temperature, the easier it is for silver nanoparticles to melt, resulting in a high sintering density, but there are problems such as cracking and peeling of the die attach paste layer due to warpage caused by thermal deformation of the substrate. To solve these problems, research is being conducted on the production of pastes capable of low-temperature sintering by using methods such as using silver flake-shaped particles, using silver nanoparticle-shaped particles, and using silver oxide. In the case of using silver flake-shaped particles, the thin thickness allows for a lower melting temperature of the silver particles. However, it has the disadvantage that it is difficult to disperse the silver particles evenly, and the size of the silver particles is not uniform, making it unsuitable for low-temperature sintering. In the case of using particles in the form of silver nanoparticles, low-temperature sintering is possible due to the high specific surface area and nano-scale size, but there is a disadvantage that printing processes are impossible due to high viscosity when used in die attach paste containing a high concentration of silver. In the case of the method using silver oxide, it can be applied to silver paste using silver coated with organic material to improve the dispersibility of silver nanoparticles. This is because silver oxide is activated at low temperatures, which lowers the decomposition temperature of the coated organic material. However, since the decomposed organic material vaporizes into a gaseous form, problems such as voids may occur after the heat treatment process. Therefore, there is a need to develop a material that can be added to conventional semiconductor die attach pastes to enable sintering even at low temperatures and exhibit excellent characteristics such as high adhesive strength and thermal conductivity after the heat treatment process. FIG. 1 is a flowchart illustrating a method for preparing a silver complex for die attach paste according to the present invention. FIG. 2 is a schematic diagram of a reaction for preparing a silver complex for die attach paste according to the present invention. Figure 3 shows the change in COOH bonding at the 1700 cm⁻¹ peak observed in the silver precursor through Fourier transform infrared spectroscopy (FT-IR) analysis. Figure 4 shows actual photographs of the synthesized silver complex for die attach paste with and without purification. The left photograph shows a perfectly purified silver complex for die attach paste, and the right photograph shows a silver complex for die attach paste with insufficient purification. Figure 5 shows the thermal decomposition temperature of the silver complex for the synthesized die attach paste, confirmed through differential scanning calorimetry (DSC) analysis. Figure 6 is a table summarizing the characteristics of die-attach paste by adding a silver complex for die-attach paste according to the number of carbon atoms in the examples. Figure 7 is a table summarizing the characteristics of the die attach paste according to the order of addition of the die attach paste in the example. The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the d