PCB Layout Recommendations
Lattice Semiconductor
for BGA Packages
18-2
Table 18-2. Lattice BGA Package Types
BGA Breakout and Routing Examples
Lattice provides several resources and different design implementations that show BGA breakout and routing of
various fine-pitch BGA packages. Different stack up and layer counts are also used to show a range of design rules
and fabrication costs. It is important to consult with your board fabrication and assembly houses as to the most
economical and reliable process for your application.
Currently there is a wide choice of BGAs from Lattice, with many devices offered in multiple packages and pitches
of BGA densities as well as non-BGA options such as TQFP, QFN and others. The BGA pitch or “center to center”
ball dimensions include, 1.00 mm BGAs, space-saving 0.5 mm pitch chip scale BGA and 0.4mm pitch ultra chip
scale BGA packages. Fine pitch packages offer advantages and disadvantages alike. Finer pitch means that the
trace and space limits will have to be adjusted down to match the BGA. Many times a design can get away with
small traces underneath the BGA then fan out with a slightly larger trace width. The PCB fabrication facility will
need to be aware of your design objectives and check for the smallest trace dimensions supported. Smaller traces
take more time to inspect, check and align etc. Etching needs to be closely monitored when trace and space rules
reach their lower limit.
The combination of fanout traces, escape vias, and escape traces that allow routing out from under the BGA pin
array to the perimeter of the device are collectively referred to as the “BGA breakout”. The fanout pattern will
arrange the breakout via, layer, and stack-up to maximize the number of I/Os that can be routed. Fanout patterns
are an important consideration for devices over 800 pins and can be follow polar (north/south/east/west) or layer-
biased directions. (Source: BGA Breakouts and Routing, Charles Pfeil, Mentor Graphics).
Package Type
Description
PBGA
Plastic BGA with 1.27 mm solder ball pitch. Die up configuration.
fpBGA
Fine Pitch BGA – Plastic BGA with 1.0 mm solder ball pitch. Die up configuration.
ftBGA
Fine Pitch Thin BGA – Thin plastic BGA with 1.0 mm solder ball pitch. Die up configuration.
caBGA
Chip Array BGA – Plastic BGA with 0.8 mm solder ball pitch. Die up configuration.
csBGA
Chip Scale BGA – Plastic BGA with 0.5 mm solder ball pitch. Die up configuration.
fcBGA
Flip-Chip BGA with 1.0 mm solder ball pitch. Die down configuration.
SBGA
Super BGA – Similar to PBGA, but with an integrated heatsink plate. This package has 1.27 mm solder ball
pitch and die down configuration. SBGA packages offer enhanced thermal dissipation capability.
ucBGA
Ultra Chip BGA – Saw-singulated plastic ball grid array package with 0.4 mm ball pitch.
WLCSP
Wafer-Level Chip Scale Package – Saw-singulated package with 0.4 mm ball pitch built onto a silicon
device. Die down configuration.