surface mount printed circuit boards components
Microelectronics Assembly on the one hand to minimize the chip and component mounting area of ??the device, the interconnect size and length, in order to improve the packing density and interconnect density; the other hand, to maximize the substrate size and wiring layers in order to accommodate possible number of circuit devices, to complete more and more important function, thereby reducing the assembly level and the external connection points. The main difference is that micro-electronic assembly and conventional electronic assembly components, devices, assembly and interconnection means. Former chip (vector, set out with small devices, etc.) multi-layer thin substrate (ceramic substrate, the thin surface mount printed circuit boards, enamel steel substrate, etc.); conventional components, the device - printed circuit boards based. Microelectronic assembly packing density than conventional electronic assembly of more than five times higher interconnect density of 6 to 25 times higher, even 100 times (thin film wiring technology), and therefore can reduce the volume of electronic equipment, to reduce weight, to speed up the computation speed (signal The propagation delay time decreases), improve reliability, reduce assembly level. (Signal propagation delay time is reduced), improve reliability, reduce pcb assembly services level.
The development of micro-electronic assembly technology began in the micro-mold components in the late 1940s and early 1950s and later developed the film and thick film hybrid circuits and microwave integrated circuits. Since the 1970s, the development of micro-electronic assembly technologies faster, and appeared on-chip carrier, set out with a large area of ??multi-chip multi-layer thick film circuit. The late 1970s to the early 1980s, the gate array chip seal carrier - ceramic substrate, enamel steel substrate and surface mount printed circuit boards components are widely used, multi-layer thin-film hybrid circuits, and organic polymer thick film circuit is also rapidly developments. Since the 1980s, with the microelectronics technology continues to evolve, as well as the large-scale, super LSI, making higher and higher integration of integrated circuits, circuit design using computer-aided analysis of the design techniques. Device package with the development of electronic technology at different times by different packages occupy a mainstream position, due to the advent of the microprocessor and memory of large-scale IC devices, such as the 1980s to meet the requirements of high speed and high-density occupy a dominant position in peripheral leads, short-pin plastic surface mount package; 1990s due to the development of ultra-large-scale and chip IC, and promoted the peripheral pin to the dense area array pin ball grid array package development and to promote its into the mainstream. Passive components to surface mount components (SMC), and continue to the development of miniaturization, the IC device package with the surface mount devices (SMD), during this period SMD has been greatly developed, resulting in a ball grid array package BGA, chip scale package CSP, high-density high-performance, low-cost FlipChip, MCM and MCM package assembly technology for SMT surface mount technology and reflow, wave soldering, and continue to narrow spacing and ultra-narrow spacing SMT development. All contributed to the more advanced packaging technology, more and more chip area and packaging area ratio close to 1, suitable for higher frequency, better temperature performance, increase the number of pins, pin spacing, increased reliability, easier to use. Is currently in the popularity of the technology and the application period.