The BGA (Ball Grid Array) is a type of microchip package. BGA package use a group of solder dots, or balls, arranged in concentric rectangles to connect to a circuit board. Some pictures by way of illustration:

In generally, the BGA converter consist of two board. The top board carry the BGA ZIF socket, that accept a certain BGA package dimension chips (for example 8x8 ball array, 11x8mm body size). The bottom board provide a proper interconnection from top board to the 48 pins, going to the ZIF socket of the programmer. The top board of the BGA converter is most expensive part of the BGA converter because of ZIF BGA socket price.

To offer you most effective solution of BGA converters, we've decided to split the BGA converter to BGA-Top and BGA-Bottom boards and offer them also separately. It results, you don't need to buy more BGA converters to program the chips in the same BGA package - you only have to use a different BGA-Bottom boards. We also come to conclusion to use the on-demand developed BGA sockets, which are insensitive to ball diameter and package thickness. This sockets also have a extreme mechanical lifetime - 500 000 actuations(!). In the case of too big tolerances of ZIF package dimensions manufacturing and in some special cases, there are used standard - 10 000 actuations - BGA ZIF sockets.

For example, if you want to program the W19B322MB in TFBGA48 and Am41DL1614DT in FBGA69 you have to order only one BGA-Top-3 ZIF-CS board and two bottom boards (BGA-Bottom-1 and BGA-Bottom-2). Another words you save - in the case of Elnec solution - more then 70% of complete BGA convertor price.