Ultrasonic hot-pressed gold flip-chip interconnection technology high-performance, high reliability, small size, light weight is consumer electronics, industrial electronics, automotive electronics, medical electronics, military electronic devices common needs and development direction. To meet the requirements of miniaturization and high performance of microelectronic packaging, flip chip will be the main interconnection form. Flip Chip interconnection technology is on the chip pad to do the convex point, and then the chip inverted base plate for the convex and the connection between the substrate, convex connection than the wire bonding wire short, high transmission speed, its reliability increased 30~ 50 times times. Flip chip plays an increasingly important part in the interconnection of electronic packages, and the gold ball convex flip-chip packaging technology is one of the most advanced flip-pack technologies in the world, and is still in its infancy in China. Gold bump than reflow convex point of conductive, thermal conductivity 10 times times higher, gold for the softer metal, the current industry has begun to use thermal inversion bonding to complete the gold bump interconnection, currently mainly used in LED, CMOS sensor, Opto sensor, SAW, Rf-switch, RF module and other products field, its Golden Ball flip process is relatively brief, low-cost, green environmental protection, has shown its unique technical advantages and prospects. Suzhou Jie Yan core in this field of technology to achieve the leading domestic and international first-class level, the company and the industry will have a positive impact, especially the gold convex block ultrasonic heat welding in the silicon substrate and ceramic substrate applications. Gold convex block flip-chip interconnection technology can achieve better signal integrity, the past 2-3ghz is IC package frequency limit, the use of gold convex block packaging technology can be as high as 10-40 GHZ, and because no need to go through high temperature, so the device itself is also no internal stress damage, is the future high-end chip packaging development direction, It is also one of the preferred solutions for 5G high frequency and high-frequency packaging. Developed countries have started to use UHF products (military or communications navigation) to obtain applications, in the field of M-E m wave filter has been widely used, at present, the domestic has just started, there is a certain degree of technical difficulties, but the market application prospects. Suzhou Jie Yan Core in the Yangtze River Delta, the first one with golden ball into the ball and 2000 pressure ultrasound
Welding technology develops the ability of sonic Filter encapsulation enterprises.
Fig. 1 AU hot-pressing ultrasonic welding Wafer-grade gold convex point ball-forming technology ultrasonic flip-chip welding is a direct interconnection between the IC I/O port and the substrate under the combined action of ultrasonic energy, pressure and heat. Thermal ultrasonic flip-chip welding has the advantages of high encapsulation reliability, high connection efficiency, simple process, low cost and strong adaptability, lower welding temperature reduces the possibility of forming intermetallic compounds between convex and pad, and is a kind of lead-free green welding, It is considered to be a new technology and technology with development potential to meet the requirements of next generation chip encapsulation. Wafer-level gold convex point into the ball technology is the first prerequisite for the realization of the gold ball flip-chip interconnection, Suzhou Jie-core introduced the United States complete sets of production equipment and technology, compatible with the production of 4~12inch wafer gold convex point. The main technical indicators are: 1 welding ball size: Before welding 62+/-5um, after welding 90+/-10um; 2 Solder Ball Spacing: Min9 0um;3) After welding the interconnect height: 10~20um;5) Welding strength: Thrust test ﹥18g/gold ball; 6 The sample can withstand the short time (~2 min) 300 ℃ high temperature;
7 Storage Temperature test: -65℃~ +125℃ Solder point virtual welding, 8 temperature impact test, conversion time is not greater than 5 min, Cycle times 500 times.
Fig. 2 Stud Bump Suzhou Czech Research Core introduction, digestion, absorbing the latest foreign chip-level packaging technology, through innovation to achieve the core device packaging localization.
Has cooperated with the domestic design company to develop 1.4x1.1mm, 1.1x0.9mm, such as CSP package of surface acoustic wave filter products, is the first to introduce such micro-encapsulation of a small number of packaging agent factory one!
Fig. 3 1.4x1.1mm CSP Saw Filter
