Optical alignment-through the optical module, the light field distribution is adjusted by using beam splitting prism imaging and LED illumination, so that the small chip can be imaged and displayed on the display. So as to realize optical alignment repair.
Non-optical alignment-according to the lines and points of PCB, align BGA with naked eyes to realize alignment repair.
Intelligent operation equipment for visual alignment, welding and disassembly of BGA components with different sizes can effectively improve the productivity of repair rate and greatly reduce the cost. BGA: encapsulated memory
I/O terminals of BGA (ball grid array package) are distributed under the package in the form of circular or columnar solder joints. The advantage of BGA technology is that although the number of I/O pins has increased, the pin spacing has not decreased, thus improving the assembly yield. Although it
The power consumption of BGA is increased, but BGA can be welded by controlled chipping method to improve its electrothermal performance. The thickness and weight are lower than those of the previous packaging technology; The parasitic parameters are reduced, the signal transmission delay is small, and the use frequency is greatly improved; * * * It can be assembled by surface welding with high reliability.
BGA packaging technology can be divided into five categories:
1.PBGA (Plasic BGA) substrate: generally, it is a multilayer board made of 2-4 layers of organic materials. In Intel series CPU, Pentium II, III and IV processors all adopt this packaging form.
2.CBGA(CeramicBGA) substrate: namely, ceramic substrate. The electrical connection between the chip and the substrate usually adopts the mounting mode of flip chip (FC). In Intel series CPU, Pentium I, II and Pentium Pro processors all adopt this package form.
3.FCBGA(FilpChipBGA) substrate: hard multilayer substrate.
4.TBGA(TapeBGA) substrate: The substrate is a strip-shaped flexible 1-2 PCB circuit board.
5.CDPBGA(Carity Down PBGA) substrate: refers to the chip area (also called cavity area) with a square depression in the center of the package.
When it comes to BGA packaging, we can't help but mention Kingmax's patented TinyBGA technology. TinyBGA is called Tiny Ball Grid Array in English, which belongs to a branch of BGA packaging technology. Developed by Kingmax company in August 1998. The ratio of chip area to package area is not less than 1: 1. 14, and the storage capacity can be increased by 2-3 times under the condition of constant volume. Compared with TSOP packaging products, it has smaller volume and better heat dissipation and electrical performance.
There are four basic types of BGA: PBGA, CBGA, CCGA and TBGA. Usually, an array of solder balls is connected to the bottom of the package as I/O leads. The typical spacings of these packaged solder ball arrays are 1.0mm, 1.27mm, 1.5mm, and the lead and tin components of solder balls are mainly 63Sn/37Pb, 90pb/10sn. Because there is no corresponding standard in this respect, the solder balls of various companies. In terms of BGA assembly technology, BGA has advantages over QFP devices, mainly because BGA devices have no strict requirements on mounting accuracy. Theoretically, even if the solder ball deviates from the pad by as much as 50% in the process of reflow soldering, the position of the device will be automatically corrected due to the surface tension of the solder, which is quite obvious through experiments. Secondly, BGA no longer has the problem of pin deformation of devices like QFP, and the flatness of BGA is better than QFP, and the lead-out spacing is much larger than QFP, which can obviously reduce the problem of solder joint "bridging" caused by solder paste printing defects; In addition, BGA has good electrical and thermal properties and high interconnection density. The main disadvantages of BGA are the difficulty of solder joint detection and repair, and the strict reliability requirements of solder joints, which limit the application of BGA devices in many fields.