Double Sided PCBs Barro board 4cm*6cm Double side (also known as Double-Sided Plated Thru or DSPT) circuits are the gateway to higher technology applications.

They allow for closer (and perhaps more) routing traces by alternating between a top and bottom layer using vias. Today, double sided printed circuit board technology is perhaps the most popular type of PCB in the industry.Vias in 2 layer PCB are used to create electrical connections that enable the routing of the traces so that they reach the opposite side of the board. Even more surface area is available for traces in a 4 layer PCB design than that in a 2 layer PCB. The 4 layer PCB design involves a prepreg layer that bonds two layers and a double-sided boards together by applying heat and pressure. Prepreg provides dielectric between the layers. Hydrochorea are discussed under the genus Balizia,
where Hydrochorea is shown to differ principally
from Balizia and Abarema in its lomentiform fruit
adapted to dispersal by water and brown (as opposed
to partly translucent) seed-coat. The commoner
species of Hydrochorea have been associated by students
of Ingeae with those American albizias that
have comparable jointed fruits (but not true loments).
Consequently, they have been transferred successively
to the Old World genus Cathormion Hasskarl,
the neotropical genus Arthrosamanea, and latterly to
a loosely defined and polymorphic Albizia. They
form, nevertheless, a closely coherent group of
species different from all the above in duration of
meristem, features of inflorescence-architecture, leafvenation,
or shape of ovary, or in some combination