Microwave integrated circuits fabrication on alumina substrate using pattern up direct electroless nickel and immersion Au plating and study of its properties

Surface resistivity and bonding strength of atmosphere plasma sprayed copper‐coated alumina substrate

“…The optimal value of bonding strength is higher than that by methods reported in the literature, such as inkjet printing and ECP. 13,20 In order to reveal the nature of the high bonding strength in the present study, we observed element distribution at the Cu and alumina interface by EDS mapping. As shown in Figure 4B, Cu and alumina are very tightly bound and there is little overlap area of Al, O, and Cu elements at the interface region, indicating that interdiffusion occurred between coated Cu and alumina, and the evidence presented is consistent with the presence of chemical bond between both Cu and alumina phases.…”

“…During the past decades, there has been an increasing interest in the metallization of ceramic substrates due to its massive demand for electronic packaging and circuit boards. 1,2 As the most widely used ceramic in microelectronic packaging, alumina has received considerable attention due to its high mechanical strength, good insulation performance, and low dielectric loss. 3 The main challenge faced is how to effectively bonding metallic circuit on the alumina ceramic substrate.…”

Effect of hydrothermal process for inorganic alumina sol on crystal structure of alumina gel

“…Alumina has excellent properties in thermal conductivity and electrical insulation and is inexpensive. These features are utilized for practical electronic devices [5][6][7].…”

Immersion gold deposition from a chloroauric acid–choline chloride solution: Deposition kinetics and coating performances

“…Electroless nickel/immersion gold (ENIG) is gaining in popularity in electronic industries, especially for surface finishing or coating for printed circuit boards (PCBs) to prevent the oxidation of nickelphosphorus (Ni-P) coating deposited on copper (Cu) surface [1] providing excellent corrosion-resistance and good solderability along with good electrical conductivity [2,3]. Three kinds of immersion gold (IG) deposition technologies have been applied to gold (Au) coatings preparation on Ni-P coating, namely, galvanic displacement, substratecatalyzed, and autocatalytic processes [4].…”

“…Although the Au coatings can be formed without a limitation on the thickness, the plating solution became unstable due to the presence of reductant [6]. Potassium dicyanoaurate (KAu(CN) 2 ) was always applied as the source of Au during IG because of its high stability [1,5,7]. However, considering the toxicity of cyanide to human health and the environment, non-cyanide Au plating solutions have been developed, such as Au(I)-thiosulfate complex solution and Au(I)-thiosulfate-sulfite mixed ligand solution [4,6].…”