Since the microBGA package is more compact than other SMT devices, it has a shorter contact length from the device pin to the outside world.
A microBGA's electrical performance shows that it has low resistance, capacitance and inductance of the short beam leads.
This means that before finalizing a microBGA for design, the designer should carefully analyze the microBGA device's details and make sure the balls' pin pitch allows for all traces fanout/ routing without using unnecessary special manufacturing requirements, and that it can be done within the allowed number of layers.
Perhaps the best-known design is the micro-ball grid array (microBGA), developed and licensed by Tessera.
CSPs and microBGAs are area array devices that offer outstanding function and electrical performance.
IPC-9850 specifies the accuracy required for each of five test components: two quad flat packs (QFP100 and QFP208); micro-ball grid array (microBGA
); 1608C capacitor; and small outline integrated circuit (SOIC16).
The system can be used by PCB and semiconductor manufacturers to conduct real-time inspection of BGA, microBGA
, flip chip, chip-on-board, bond wires and other applications needing precise measurement.
Q: What is the nature of the residue remaining under the microBGA?
A high I/O microBGA, with a low standoff under standard aqueous (water only) cleaning techniques produced a product that left visual residues and ionic levels well above cleanliness limits for good electrical performance.
Components assembled included four area array packages: one microBGA
with 46 I/O chip scale package (CSP), one 48 I/O CSP, a flex-based 144 I/O and a laminate-based 64 I/O CSP.
However, consider a 20-mil micro ball grid array (microBGA) with a 10-mil aperture in a 5-mil-thick stencil.
Figure 5 shows the relative paste volume for a 20-mil pitch microBGA with 10-mil square apertures with 2.5-mil radius corners.