|
406 Frequently Asked Questions
¨
IC test: Please explain how you test IC’s. Will you check all pins of
the IC or only a few unique pins?
Analog IC
Verification - Each lead on every IC is automatically characterized with
respect to itself and all other points on the board. Two measurements
are made on each IC protection diode providing a unique signature for
each IC enabling detection of SMD lifted pad faults as well as missing,
reversed, or wrong IC faults. The two measurements that are made are: Vf
(forward voltage drop) at 1mA and Vf at 5mA. These are compared to
the compliance Vf and delta Vf. These levels are fully programmable.
¨
How do you handle bused IC’s? What type of defects can you detect in
this case?
The most
efficient way to test bussed IC’s is with Agilent’s (HP’s) Test
Jet. This vectorless test method provides an efficient way to isolate
the most common surface mount technology process faults which are open
solder joints. Keep in mind that the Testronics Analog IC verification
technique will find open solder joints on all IC’s that are not
bussed. Therefore, Test Jet is only needed on a portion of the IC’s. A
probe plate is positioned directly over the IC to be tested. The
capacitance is measured between the plate and each lead of the IC. If
the lead of the IC is not soldered to the board, the capacitance value
will be an order of magnitude smaller than a properly soldered joint.
¨
What is your experience with different IC manufacturers? Will it effect
the test results?
Our 19 years of experience in the test
industry has lead us to the development
of an IC test method which provides consistent
test results regardless of the manufacturer of the component. The
protection diodes found on virtually every IC produced, do have varying
parameters from IC to IC but not normally within the same IC. Typically
the Vf or “turn on voltage” will vary between .60 V and .90 V and the
delta Vf will vary between 200mV and 300mV. Our software is set up so a
diode action with default values is inserted automatically into the test
program for each IC. Any of these parameters can be adjusted. The
following is an example of the automatically generated program code and a
graphical representation of our measurement technique.
The * symbol denotes the beginning of the data
group, the ! mark denotes the end of the data group.
*diodes
;This data group is automatically
built during
anode1_cathode1
;diode learn in the build menu.
anode2_cathode2
;This data group is specific to the quantity and
.
;location of protection diodes on an IC.
.
.
anodeN_cathodeN
!
The action ndiode tests a group of diodes.
#ndiode
Vmax= .9V
;all argument values are fully programmable
Vmin= .5V
Is=
1mA
dV= .2V
dI=
4mA
Time= 1ms
!
¨
Do you need a known good board (“golden board”) in order to write the
test program?
No, certainly a “golden board” is the
ideal situation, however the real world is rarely ideal. The industry
preference for developing a test program which will find all board faults
without reporting false failures is to use a group of boards along with
the schematics to verify component and circuit measurement variances. One
board can be used to automatically generate the base test program, learn
the nets for opens and shorts, and learn the IC protection diodes. Then
several other boards can be used to fine tune the test program.
¨ What support arrangements do you
typically provide?
In addition to our unlimited telephone
support and one year warranty, we provide our customers with the option to
communicate through the e-mail which allows for efficient debugging of
test program files. The test system is warranted for a period of 1 year
from the date of shipment. During this period there is no charge for parts
or labor on items returned to Testronics for repair. There is also no
charge for replacement items sent to the customer. If you have a high
volume production facility, we recommend purchase of a spares kit for use
in the rare event that a hardware failure occurs. Service and support are
handled out of our home office in McKinney, Texas. Next Day Warranty
replacement is are accomplished via Federal Express. Typical mean time to
repair the system is less than 30 minutes. Full training is offered as
well as programming services.
¨ Do you provide telephone support?
Yes, Testronics offers unlimited free of
charge telephone support.
¨ Can you provide a ‘turnkey’
fixturing solution?
Yes,
Testronics offers comprehensive software services for automatic test solutions. These include test programming and fixturing services. You
receive the expertise, resourcefulness, reliability, and ready support of
an entire engineering department without the added personnel cost.
¨ What is the max node count a Testronics
test system can handle?
This is strictly receiver dependent.
Testronics has developed an open architecture electronic design. We build
test systems in excess of 20,000 points for backplane applications.
However, the most popular interface used is the GenRad 2270 style
receiver, which gives the test system a maximum of 1600 points. This
receiver is standard in our 406A and 406C. We also support the Teradyne
style 1800 receiver and the GR228X style receivers.
¨ What types of fixtures do Testronics
test systems use?
We use industry standard style fixture kits
that mate to the receivers listed above. These kits can be bought from
many different vendors globally. We can also use paddle card, mechanical
push down, pneumatic press, or custom designed fixtures. The type of
fixture used is based more on the customer’s UUT than the test system
type. As long as the test system is fitted with an industry standard
receiver, just about any type of interface to the UUT can be achieved.
¨ Is the Controller PC based?
Yes, Testronics has intentionally taken advantage of the standardization of
PC’s using MS Windows OS. The system utilizes the PC’s parallel port
for communication between the test system and the PC. This allows the
customer to easily network the test system, swap out the PC with a minimum
of down time, shorten the learning curve for the operators, and many more
advantages.
¨
Can the test program support multiple variants or panelization of one
board?
Yes, by
inserting branching and conditional variables into the program, the
operator can be prompted as to which variant he wants to test and that
portion of the program will be run. Panelized boards are programmed by
debugging the first board and then running a macro to automatically expand
the program for the rest of the boards in the panel. Testronics Operating
System (TOS) provides automated test program generation with intuitive
software tools and input screens for programming ease.
¨
What component tests can it do?
The fault coverage consists of shorts,
opens, resistors, capacitors, inductors, diodes (LEDs and Zeners),
transistors, IC verification, complex impedance, transformers, solder
bridges, missing , reversed, incorrect and/or defective components.
Inductance and capacitance are measured as
complex impedance with the use of a multiple frequency AC stimulus
measurement unit. The frequencies available are 15.9 Hz, 159 Hz, and 15.9
kHz.
We can test for transformer polarity,
however, the range of test is a function of impedance value. TOS provides
a transistor action which tests FETs as an analog switch. Maximum coverage
can be achieved by using the diode test in addition to the transistor
test.
¨
Does your system provide for expansion into functional testing?
Yes, the 406 Analog In-Circuit test system
is designed with a scaleable, open architecture and modular plug and play
system cards. The system provides the user with almost unlimited
flexibility by using a VME style bus designed specifically for in-circuit
test. A Testronics instrument card combined with IEEE instruments can
create functional level tests. The IEEE functional signals can be sent
bi-directionally to any point on the test system matrix. For example, one
of our customers runs the standard MDA test, powers up the board with a
programmable HP PS, digitally tests a display driver with National
Instruments computer digital I/O cards, and also runs an interactive light
and button test. This has allowed them to combine their functional test
with their ICT test, reducing equipment costs, labor costs, and handling
time.
¨
Does it support powered tests?
Yes,
the 406 can be configured with either the 10V solid state switch cards for
MDA testing or with the 50V relay switch cards for power up testing.
Usually the customer chooses his own power supplies and we integrate them
for him. These can be controlled through IEEE if programmable or with or
power up relay boards if fixed.
¨
Does the software provide the ability to give control to another
executable program and return to the Testronics test program?
Yes, TOS provides an action or function
called “exec” which when inserted into your test program, relinquishes
program control to an executable file developed from a language of your
choice and then returns to test program.
|
