Characteristics of flip-chip FC and traditional SMT
Flip-chip FC, wafer-level CSP, and wafer-level package WLP are mainly used in the new generation of mobile phones, DVDs, PDAs, modules, etc.
1、 Flip chip FC
A flip-chip is defined as a wafer that may not be redistributed. Generally, the tin ball is less than 150 um and the ball spacing is less than 350 um.
(1) Characteristics of flip-chip
① Traditional front mounted device, chip electrical side up;
② Flip chip, electrical side down;
In addition, flip-chip FC is called flip-chip because it needs to be flipped when mounting the ball on the wafer. FC has the following characteristics:
① The base material is silicon, and the electrical surface and soldering protrude under the device.
② The smallest volume. The ball spacing of FC is generally 4-14 mil and the diameter of the ball is 2.5-8 mil, which makes the assembly volume minimum.
③ The lowest height. FC assembly directly assembles the chip on the substrate or printed circuit board by reflow or hot pressing.
④ Higher assembly density. FC technology can assemble the chip on two sides of PCB, which greatly improves the assembly density.
⑤ Lower assembly noise. The noise of the FC assembly is lower than that of BGA and SMD.
⑥ Nonrepairable. FC needs bottom filling after assembly.
At the same time, the connection method of FC solder bump material and substrate is called UBM. It is a ball placement process at the bottom of the device to realize the bottom solder ball structure redistribution technology, forming a solder wettable terminal. At present, the most popular and simplest UBM technology is using SMT solder paste and reflow soldering.
In the past 20 years of SMT chip processing, combined with some characteristics of flip-chip, it is not difficult to see that it is small, because it is different from the common technology because it is not repairable, either good or scrap, the cost is a significant disadvantage. Therefore, there is no such product in many PCBA processing.
Article and pictures from the internet, if any infringement pls firstly contact us to delete.
NeoDen provides a full SMT assembly line solutions, including SMT reflow oven, wave soldering machine, pick and place machine, solder paste printer, PCB loader, PCB unloader, chip mounter, SMT AOI machine, SMT SPI machine, SMT X-Ray machine, SMT assembly line equipment, PCB production Equipment SMT spare parts, etc any kind SMT machines you may need, please contact us for more information:
Hangzhou NeoDen Technology Co., Ltd
Web: www.neodentech.com
Email: info@neodentech.com