The reason why the chip mounted is called "flip chip" is relative to the traditional wire bonding connection method (WireBonding) and the post-balling process. The electrical side of the traditional chip connected to the substrate by wire bonding faces up, while the electrical side of the flip chip faces down, which is equivalent to turning the former over, so it is called "flip chip".   The essence of flip chip is that on the basis of the traditional process, explosion   proof   lighting   area and the electrode area of the chip are not designed on the same plane. At this time, the electrode area is mounted toward the bottom of the lamp cup, which can save the process of wire bonding. , but the precision of this process of solid crystal is relatively high, and it is generally difficult to achieve a high yield.   Requirements for flip chip:   The base material is silicon; The electrical surface and solder bumps are on the lower surface of the component; Underfill is