Transcript IPC-2221 3.5.6.1 Bare Board Testing

IPC-2221
3.5.6.1 Bare Board Testing
Bare board testing is performed by the printed
board supplier and includes continuity,
insulation resistance and dielectric
withstanding voltage. Suppliers can also
perform testing of controlled impedance
circuitry. Continuity tests are performed to
assure conductors are not broken (opens) or
inadvertently connected together (shorts).
Insulation resistance and dielectric
withstanding voltage testing is performed to
assure sufficient conductor spacing and
dielectric thickness.
IPC-2221
3.5.6.1 Bare Board Testing
There are two basic types of continuity
testing; Golden Board and Intelligent. In
Golden Board test, a known good board
is tested and its results are used to test
all the remaining boards in the lot. If there
were an error in the Golden Board, an
error in all boards could go undetected.
The Intelligent test verifies each board
against the design's electrical net list. It
will not miss the defects which could be
undetected in a Golden Board test.
IPC-2221
3.5.6.1 Bare Board Testing
Designs which do not have all electrical
connections available from one side of
the board (such as boards with blind or
buried vias, components on both sides
with via holes solder resist tented or
boards bonded to both sides of
heatsinks) will require Flip or Clamshell
testing. Flip testing tests one side of the
board and then the other on two
separate fixtures.
IPC-2221
3.5.6.1 Bare Board Testing
Connections which require contacting
both sides of the board are not
evaluated. Clamshell testing uses two
fixtures which come in contact with
both sides of the board at the same
time and is capable of testing all
connections. Flip and Clamshell testing
costs more than testing performed from
one side of the board only.