Philway Products Inc.
701
Virginia Ave., Ashland, OH, 44805 Ph 419-281-7777
Fax 419-289-3447
ELECTRICAL TEST (ET) METHODS
CONTINUITY & ISOLATION
(Test Methods 1, 2 and 3): Philway strongly recommends that all
multilayer Printed Circuit Boards (PCBs) be ET'd (if you do not want
us to ET we would like you to state so for our record). We also
recommend that all 2-sided boards be ET'd. For most 1-sided boards
ET is a Customer option. For Military-type multilayer PCBs -Type 3
ET is a specificational requirement (1 or 2-sided typically is not).
While nothing in life is 100% guaranteed, ET will give both Philway
and our Customers an added assurance of functionability from the
standpoint of opens & shorts within the conductor pattern or nets.
Factors for Customers to consider, as to whether ET is economically
justifiable involves, the cost of fixturing vs Customer
responsibility for the cost of assembling PCBs containing opens or
shorts (the possibility of human visual inspection not catching
every open or short defect definitely exists). Considerations to ET
would involve the PCB conductor line & space density (a very
important factor especially when less than .010 to .012) along with
the board (or array) size (especially if larger than 50 square
inches), quantity to be ordered (especially if more than 50 pieces)
& possibility of Engineering Revision (the projected stability of
the board design). Philway assumes no responsibility or liability
for any cost beyond the cost of the bare board itself, this includes
assembly & component costs. If ET voltage is not Customer specified,
we assume no liability for bare board test damages.
Philway is using Barco
UTEST CAM software to generate "downloaded" a net list (net ends) ET
program for fixture (ETF) or fixtureless testing. We can also
generate a combined test program using both fixture & fixtureless
testing. The only data needed are the Gerber and Drill information
supplied to manufacture the board. Without CAD data netlist
our normal procedure is to generate a netlist by "Self-Learn/Golden
Board."
Philway is capable of
ET'ing your boards in five different methods with associated
different costs. All RFQ’s and P.O.’s must specify if ET is
required and if required, what type/method is to be used with the ET
parameters. If a specific test method is not
specified in your quote, Philway will quote the single-sided test
method with all midpoint/intermeidary vias edited.
Below is a list of the five
standard ET methods used:
1.
Grid (Bed of Nails) Single-Sided
ETF (Default test parameters 40V, continuity 100 ohms,
insulation 500k ohms). Single sided ET for all net ends (lead holes
and all surface mount pads) only on one side of the board, with all
vias edited.
2. Grid (Bed of Nails) Double Sided ETF
(Default test parameters same as single-sided ET) for net ends (lead
holes and surface mount pads) on both sides of board. Testing of
both sides simultaneously by a top and bottom universal grid tester
(all midpoint/intermediary vias edited unless otherwise specified).
Test points, based on
finished hole sizes (FHS), should not be any closer than (FHS of
.010 - .015 = .033; FHS of .016 - .026 = .040, FHS of .027 - .034 =
.048) radius of one another and some points may have to be edited to
achieve this. Maximum size for test is approximately 15 inches by 18
inches on .100 grid (Universal bed of nails). SMD/SMT fixture
minimum is .020 pitch and SMD pads at least .050 long (if shorter,
we will use split test or probe), using .016 or .020 dia. staggered
test pins. Test voltage up to 250 volts (Military applications
must specify max ET Voltage). Special ET includes any tighter
tolerances, voltage or size parameters than above.
3. "Flying Probe-
Fixtureless" ET.
We can only work with Cad Net list or Gerber downloaded data for
this tester. If Cad Netlist or Gerber information is not
available, this test can not be used. Single or
double-sided test are both available. Contact Philway for details on
continuity and isolation verification. Maximum Test Area is 15.7 x
20.4, Test Voltage is 25 to 500 VDC, and Standard Resistance Range
is 10 ohms to 10 megohms.
IT IS REQUESTED THAT
CUSTOMER SUPPLIED NETLISTS COMPLY WITH IPC-356A
4. TDR Impedance (Contact
Philway for details).
5. Hi-Pot (Contact Philway
for details).
Form 12-09 E Rev- 12/3/07 For most recent version of this
document, go to the Philway Products Website at: www.philway.com