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HEWLETT
PACKARD
t-
SERVICE INFORMATION FROM HEWLETT-PACKARD
MARCH-MAY 1983
atic Za akes Scrag
Static electricity is a familiar
phenomenon which, except for an oc-
casional mild shock or annoying
"static cling", doesn't seem very
serious to most of us. In fact, many
people in the electronics industry
reject electrostatic discharge (ESD)
as a major cause of component fail-
ure and hence, of equipment failure.
It's not surprising that many people
doubt the magnitude or even the re-
ality of the ESD problem. In many
cases a damaged part exhibits little
or no physical damage when ob-
served in a cursory microscopic in-
vestigation. Unfortunately, many
electronic components can be dam-
aged or destroyed by ESD at poten-
tials well below a person's range of
sensory perception. Passive as well
as active components are susceptible
and the damage ranges from a slight
degradation of a parameter to catas-
V
trophic failures such as short cir- How Severe You Ask?
cuits. The catastrophic failures are technologies is also a trend towards
easy to discover and analyze, it's the much greater ESD susceptibility.
One source in the electronics indus-
"wounded" parts that fail sometime try estimates we may be losing as
later that are hard to track down Who would have thought 10 years much as ten billion dollars annually
and prove ESD-caused damage. ago that engineers would ever have from ESD. There could be as much
to worry about types of floors, floor as 500 million dollars lost at the
It is this difficulty in recognizing polishes and cleaners, bench tops, component level because of the ex-
ESD-related failures that is one of shoes, carts and wheels, antistatic tensive damage caused by ESD. Dick
the main reasons for lack of ESD sprays, masking tape, plastic work MOSS, Hewlett-Packard Corporate
awareness. And this is the most im- order holders, and other ESD related Reliability Engineering Manager,
portant part of the battle against articles? Today we do have to think states, "Through ESD control we can
static ZAP-the need for s t a t i c of these things because the progress reduce in-house failures and field
awareness-on the part of top man- in internal protection circuits, in re- failures by at least ten percent." Mr.
agement right on down to packing lation to the trend towards smaller Moss foresees Hewlett-Packard, as a
and shipping or receiving depart- geometry as mentioned above, does whole, spending over a million dol-
ments. ESD control measures must not appear to be able to keep up. lars in establishing static control
[' be implemented because the trend Thus, ESD problems will be getting programs. Over half our divisions
towards smaller geometry, lower more severe i n t h e immediate have already incorporated electro-
power, and lower voltage future. static control programs. Several
Part No. 5952-0114 @ Hewlett-Packard 1983
WWW.HPARCHIVE.COM
I_- -- _I -_
Hewlett-Packard divisions have im-
plemented static elimination pro-
grams t h a t have had significant
documented measurable results.
Example 1
In March 1980, one HP Manufactur-
ing Division conducted an experi-
ment to determine the effects of
handling unprotected integrated cir-
cuits. Eighty-seven circuits were
tested and found good. Forty circuits
were put in a plastic box as usual;
forty-seven were carefully placed in
antistatic foam.
The devices in the plastic box were
handled by several people in the IC
department and returned to the box.
The forty devices were then retested. Figure 1. This is a MOS FET with the oxide and metal removed to show the craters in the gate.
Thirty-one circuits failed the PC The rough area at the bottom is a metal pad for a connector. Magnification is 2200X.
test, nine passed.
touched the edge connectors with a n on certain series of assemblies.
The forty-seven circuits in the anti- ESD probe. All ten boards were Employees were trained on ESD and
static foam were also retested. All damaged by a 650 to lOOOV electro- its prevention. Static-safe worksta-
were found good and returned to the static charge. The failures were ver-
ified by inserting the boards into an
tions were outfitted in production '
antistatic foam. area. Within three months, failures
operating instrument. Repair work dropped to less than 3%.
revealed that the LS TTL was the
This experiment eventually resulted most sensitive component on the
in the reduction in time for board board-every component replaced Understanding the Process
repair. For example, standard time was the LS TTL. The 8080s and TTL
for board repair on one of this divi- did not fail but were damaged. Static electricity is actually elec-
sion's systems has been reduced tronic charge at rest on a surface.
from 13 to 5.47 hours per unit. ESD When the charge becomes suffi-
handling procedures implemented in This brings up two important points ciently large, a n electrostatic dis-
another production area improved about ESD. 1-People can often charge can take place. The discharge
the yield of a bipolar LSI part from carry 1000 to 5000 volts without takes place of course when a charged
22% to 100%.And later, ESD protec- ever feeling the sensation of any dis- person touches a part or a charged
tion procedures were implemented charge under 3500 to 4000 volts. part touches another conductive sur-
to lower failure of a hybrid chip used 2-Components mounted on a PC face. How does the surface become
widely throughout the company. board have increased risk of ESD charged? There are three types of
After t h i s program was im- damage because each printed con- static generators.
plemented, DOA line returns fell ductor (or wire) is a highway con-
from 25% to 4% within two months. necting t o several devices. A dis-
charge to that conductor stresses Triboelectricity
Example I1 several devices at once rather than
just one. The most common static generator is
Another H P Manufacturing Divi- triboelectric charging, where two
sion made an informal test in Au- materials in contact are suddenly
gust 1980 to determine component Example I11 separated o r rubbed together. A
sensitivity on a PC board manufac- common demonstration of this prin-
tured in large quantities. Ten boards In mid 1980, one of our computer ciple is pulling mending tape off its
were taken from line stores and ver- divisions implemented an aggres- roll to generate in excess of 5000
ified as good. Using a static sive ESD prevention program to volts. A person can develop a sig-
generator, the t e s t personnel lower their 23% in-plant failure rate nificant charge on his or her body
2 BENCH BRIEFS MARCH-MAY 1983
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with a relatively simple movement, increasing relatively harmless volt- sitivities (note the non-MOS devices
such as walking across a floor or re- ages to dangerous levels. The famil- in the extremely sensitive group).
moving a coat. Strolling across a iar equation Q = CV (charge equals
r` vinyl floor can generate as much as
12,000 volts which is enough static
capacitance times voltage) can be
solved for voltage and we quickly see Table 1. ESC sensitivity of typical
to give a slight shock. The simple act that if charge is constant, voltage components (based on meas-
of shifting the body can generate increases as capacitance decreases. urements using 100 picofarads
hundreds of volts. The charged per- Thus a harmlessly low voltage on a discharged through 1.5 kilohms)
son then touches a device, say dur- component or human with a high
ing a hand assembly operation. The capacitance to ground can become a Extremely Sensitive
energy in the body is transferred harmful voltage as the object is 0 to 1 Kilovolt
either to the device, or through the moved further from a ground plane, 0 Unprotected MOS: Field
device to ground. And this discharge for example when an assembly on Effect Transistors (FETs) and
is usually much more than many the floor or table is picked up, you Integrated Circuits (ICs)-
circuit packs can handle. change its capacitance and hence especially Very Large Scale
voltage. Now, when you ground the Integration (VLSI)
So how do the parts themselves be- assembly it will more than likely be 0 MOS Capacitors (Op Amp
come charged by the triboelectric damaged whereas before, the charge internal compensation)
process? Consider for example, that might not have been high enough to 0 Junction FETs and low cur-
most integrated circuits are trans- be harmful. rent Silicon Controlled Re-
ported and shipped in plastic tubes. ctifiers (SCRs)-less than
Charges can be developed on these This brings us to the three myths of
.15A
devices because of movement in the Electrostatic Discharge (ESD).
Microwave a n d Very High
tube. When a charged device is Frequency (VHF) transistors,
emptied from t h e tube and The Three Myths of ESD Microwave and VHF ICs-
grounded, the rapid discharge can especially Schottky
cause the device to fail. Myth No. 1. Only Metal Oxide 0 Precision IC voltage
Semiconductor (MOS) Devices regulators-less than 5%
f" Induction are Susceptible to ESD. 0 Precision thin film
resistors-less than .l%
A second, more subtle type of char- While it's true that MOS devices are Low-power thin film
ging is called "induction" because extremely sensitive, tests have resistors-less than .5w
the electrostatic field of a charged shown that other types of compo- 0 VLSI with dual-level metalli-
surface induces polarization of a nents a r e also j u s t as sensitive. zation
nearby conductive body. If there is a Table 1 shows a spectrum of sen-
discharge path for t h i s induced
charge, a n ESD may occur im-
mediately.
A good example of this principle is
when a person handles a printed cir-
cuit board assembly wrapped i n
plastic bubble wrap, or an individual
integrated circuit located inside a
plastic bag. The person handling the
plastic induces a charge onto the
plastic which i n t u r n induces a
charge on the piece inside. It does
not matter if the person has a wrist
strap on or not. When the person
touches the piece to remove it from
the plastic, the sudden discharge
causes the ESD damage.
r` Capacitive
Capacitive charging is a third mech- Figure 2. This is a blowup (23,OOOX) of one of the craters shown in Figure 1. The crater is -1
anism which can be responsible for micron wide and contains fragments of melted metal.
MARCH-MAY 1983 BENCH BRIEFS 3
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Sensitive battery and consequent early re- and to allow charge to bleed off to
1 to 4 Kilovolt placement. In both these cases, ESD ground more easily. But the real
MOS with protection net-
works (CMOS, NMOS, PMOS)
is often not suspected since the evi-
dence seems to point elsewhere.
reason the myth is so widely be-
lieved is that the voltages encoun-
9
Schottky diodes tered during high humidity are gen-
High-speed bipolar logic: erally less than the threshold of per-
Emitter Coupled Logic (ECL), Myth No. 3. Only Low Humidity ception of the average person, which
Low Power Schottky- Environments Allow the is typically 3 to 4 kV. This is also the
Transistor Production of ESD. voltage necessary to cause a visible
Transistor Logic (LS-TTL), and audible spark from a fingertip or
Schottky TTL (S-TTL) There is a widely held belief that handheld tool to a conducting sur-
Linear ICs there are no static electricity prob- face. Table 2 illustrates some typical
lems when the humidity is high. It is sources of ESD and the relationship
Less Sensitive true that the increased surface con- between relative humidity and the
4 to 15 Kilovolt ductivity at high humidity tends to ESD value. Charge levels are re-
Small signal diodes-less reduce triboelectric generation, t o duced in high humidity environ-
than l w spread charges over larger surfaces ments, but are still well within the
Small signal transistors-less so that the fields are less intense, undesirable range.
than 5w
0 Low-speed bipolar logic (TTL,
Table 2. Typical electrostatic voltages versus relative humidity
Diode Transistor Logic [DTl],
High Threshold TTL [H-TTL])
Quartz and piezoelectric ESD Value
crystals
70-90% 10-20%
Source
RH RH
Myth No. 2. Only Unmounted
Components are Susceptible to Kilovolts
ESD.
Walking across vinyl floor 0.25 12
This is only true if the assembly has Walking across synthetic carpet 1.5 35
protection circuits at all sensitive Sitting on foam cushion 1.5 18
nodes, particularly where a sensitive Picking up standard plastic bag 0.6 20
device input is routed to a connector Sliding plastic box on carpeted bench 1.5 18
pin. What usually happens is that Pulling tape from PC board 1.5 12
mounting components on printed Skin packing PC board 3.0 16
circuit assemblies increases the risk Triggering standard solder remover 1.0 8
of ESD damage because each printed Cleaning circuit with eraser 1.0 12
conductor connects t o several Freon circuit spray 5.0 15
devices. A discharge to that conduc-
tor thus stresses several devices at
once rather than just one. ESD Prevention alty for applications requiring
high-performance.
CMOS circuits subjected to an ESD It is easier and more effective to
while they are powered have an ad- remove static from the environment Self-control of ESD prevention in-
ditional risk-latchup. Latchup is a and bleed the charges from people off volves a program revolving around
parasitic pnpn avalanche usually to ground than to rely on protective the following basic rules.
caused by an input or output "glitch" devices built into the circuitry
which exceeds the supply voltages so (which seldom exceed 2 kV in protec- Rule No. 1. Treat all electronic
that the parasitic device is triggered tion). The design and effectiveness of parts and assemblies as static
"on." The CMOS then tries to shunt protective circuitry varies between sensitive.
the power supply to common and the manufacturers. Zener diodes may Don't touch leads, pins, or traces
usual result is overheating and not act quickly enough to protect the while handling.
catastrophic failure. In some very more sensitive components. The use Keep parts in original containers
low power CMOS devices used in
battery operated products, the
of limiting resistors is restricted to
the voltages they can withstand.
until ready for use.
Discharge static before handling
3
latchup is not damaging to the IC Also, protective circuitry sometimes devices by touching a grounded
but increases the battery drain to reduces t h e performance of t h e metallic surface such as a rack or
the point of early discharge of the device. This could be a heavy pen- cabinet. Better yet, use a wrist
4 BENCH BRIEFS MARCH-MAY 1983 WWW.HPARCHIVE.COM
strap grounded through a one
megohm resistor.
r-' 0
0
Do not slide static-sensitive
devices over any surface.
Notify your manager or static
coordinator of mishandled
parts-they may pass final test
but be degraded enough to fail in
the field;
Rule No. 2. Handle all sensitive
parts and assemblies at "static-
safe work stations."
A static-safe work station is defined
as having:
0 Conductive table mat grounded
through a one megohm resistor. Figure 3. These are the spiral cuts in a Figure 4. Closeup of damaged area shown
Each mat should have two swivel precision one megohm metal film resistor. in Figure 3. This is a good example of a
connectors, for connecting wrist The arrow shows where ESD arced across "wounded" part just enough out-of-
straps, one for the worker, the the gap melting metal causing a bridge. tolerance to cause a circuit problem-very
difficult to troubleshoot due to parallel
other for supervisors, inspectors, resistances.
etc. Work station must be monitored
long-sleeved smock or sleevelets
0 Conductive wrist strap in contact
made of ESD protective material. for proper grounding, for safe pro-
with bare skin and connected to
Antistatic smocks a r e recom- cedures and static hazards.
swivel connector on mat through
mended for general wear and Grounds and wrist s t r a p con-
one megohm resistor. Alligator
especially when handling class 1 tinuity should be checked with a n
clips should never be fastened
(sensitive to 1000 volt) material. ohm meter. Work stations, includ-
onto the table mats because their ing materials and containers
0 Use only proper containers for
area of contact is too small to be
storage such as static protective should be checked with a static
effective as a ground conductor.
bags, conductive or antistatic meter.
0 All metal equipment grounded:
trays, and tubes of integrated cir- Spray antistatic solution on a
soldering irons, work benches, cuits. No paper or cards are to be clean cloth and wipe top of work
machinery, electrical equipment, inside the containers. benches, hand tools, chair seats,
fixtures, cleaning nozzles, lazy 0 Gloves, if used, are to be cotton or and backs.
susans, or turntables, stands, antistatic; no synthetics. Clean conductive m a t s with a
cabinets, and shelving made of mild detergent and water or with
0 Carts, if used to transport sensi-
metal must be grounded. antistatic solution. (Dirt or wax
tive items, should have carrying
One common ground at any one can insulate the surface and pre-
surfaces covered by conductive
work station. Example: table mat vent conductivity).
mats and at least two conductive
and equipment must connect to
wheels. Rule No. 3. Package parts
same ground. Screws on metal
0 A conductive floor mat, which is
junction boxes of a properly properly for storage or
grounded AC power line are a grounded, and conductive heel transportation.
straps should be used where walk-
good place to attach ground cable. Envelopes or containers should
Keep work area clear of noncon- ing is necessary and wrist straps
cannot be worn. A new heel strap have a warning label on the out-
ductors. No common plastics, side (JEDEC/EIA symbol
polybags, cardboard, cigarette must be used each day. An alter-
native to the heel straps are shoes preferred).
packages, candy wrappers, work
with conductive soles designed
envelopes, synthetic mats, or un-
t o be worn i n antistatic
1
r
grounded metal plates. No rugs on
environments.
floor, work surfaces, or shelving.
0 Brushes, if needed must have
Clothing must never come in con-
natural bristles; no synthetics.
tact with components or assem- L ELECTROSTATIC
SENSITIVE
blies. Short sleeves are preferred In addition, the following practices DEVICES
and long sleeves must be either must be followed weekly to maintain
rolled up high enough to prevent the static-safe work station and a
contact with or close proximity to safe (free of electrical shock) work Figure 5. Approved label for electrostatic
sensitive parts, or covered by a area. sensitive devices.
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MARCH-MAY 1983 BENCH BRIEFS
---s___~ /
Store and transport sensitive
p a r t s and assemblies only is
ESD-protective enclosures. The
best protective enclosure is a
"Faraday cage." Metal, metallized
plastic and carbon-loaded plastic
are all examples of such contain-
ers, with the metallized plastic
having the advantage that it is
semitransparent so that the con-
tents can be seen without opening
it. The difference between the
"Faraday cage" and the "pink-
poly" bags is as follows: the
"pink-poly" bag guards against
static being created when the part
slides around inside or when the
outside of the bag is rubbed. But if
a person's body is charged and
picks up the "pink-poly" bag, the
part inside the bag will become
charged by the induction method.
Then when the bag is opened and
t h e p a r t removed, t h e sudden
Figure 6. Example of a static-free workstation for board repair.
grounding of the part can gener-
ate the ESD damage. On the other
hand, the "Faraday cage" shunts nents increases. Protective and pre- an aid to the buyer in making an
any such inductive charges ventive measures are fairly simple intelligent choice by discussing the
around the part providing com- but won't succeed unless they are pros and cons, strengths and weak- rl
plete protection. coupled with static awareness edu- nesses and potential failure mecha-
When packing parts for storage or cation. Static damage prevention is nisms of t h e various different
transportation, use antistatic an example of a process which is generic materials presently avail-
packaging and pack the parts only as good as its weakest link. The able for ESD protection. The infor-
tightly to prevent motion which components remember! mation and data contained in this
could generate static. document are not to be construed as
0 Makes certain that the tubes used a n endorsement o r prohibition of
to store and transport ICs are the any specific product.
antistatic type. Plastic tubes will Editor's Note: The recent explosive
cause a static charge build-up on growth of the ESD protective prod- The document is:
the ICs when they slide out of the ucts market has introduced a vast
tube. array of products to the potential ESD Protective Material and
0 Ensure that charts, wheels, cas- buyer. Unfortunately, the multitude Equipment: A Critical Review
ter, frames and shelves are con- of voices and choices in the market
ductive. If you are transporting place has tended to make the selec- Spring '82
sensitive electronic equipment on tion of an optimum product rather
a cart with rubber wheels pushed difficult . Order No. SOAR-]
by a person wearing crepe or
heavy rubber soled shoes, you just Therefore, "Caveat Emptor," let the Prepared by Norman B. Fuqua
have another form of a "Van de buyer beware, is especially germane IIT Research Institute
Graaff' high voltage generator. to the purchase of ESD protective Under contract to:
materials. For the maximum quality Rome Air Development Center
Conclusions assurance, substantial purchases Griffiss AFB, NY 13441
should only be made after a thor-
ESD damage is responsible for an
unknown but significant percentage
ough review of the market, a formal
product qualification program, and
Contact: 1
of electrical component failures and lot sample testing to assure consis- Harold A. Lauffenburger
is likely to increase as the use of tent quality. As an aid toward this Reliability Analysis Center
smaller, faster, lower-power compo- end, a document has been written as at Griffiss AFB
@\ CH BRIEFS MARCH-MAY 1983
\ --
WWW.HPARCHIVE.COM
I-_ _ _ .
-- _ _ _.
Acknowledgements programs for HPs major repair cen- was performed by Mr. Richard Moss,
ters. Other companies are also heav- HP Corporate Reliability Engineer-
The words, Figures and photos for ily involved in ESD prevention pro- ing Manager, and producer of an HP
t h i s article were compiled from grams. A lot of source material was video tape called "Static Zap Makes
many different sources, both within contributed by Mr. George K. Scrap." Copies of this 30-minute
and outside of Hewlett-Packard. Mr. Hagge, Production Inspection Group tape are available through your
Mike Ward, Product Assurance Leader at the E. F. Johnson Com- local H P office. Order H P p a r t
Manager at H P s Computer Support pany. He included material he had number 90383R and specify A for
Division and Mr. Thomas Edmonds, gathered from Mr. C. Fred Mykka- VHS-SP, or B for Beta 1, or D for
Product Assurance Manager a t H P s nen, editor of a Honeywell publica- 314 " Umatic tape format. For exam-
Instrument Support Division are ac- tion called Component Comments. ple, 90383RB orders the tape in
tively engaged in ESD prevention Final editing for technical accuracy Beta 1format.
New HP 3497A New 3497A Documentation
Manuals HP Price: Before After
Part Number Title July 31 Aug. 1
We are pleased to announce that the
following three-volume set is now 03497-90019 Operating, Programming and $35 $75
available. These manuals were re- Configuration Manual
written to provide information that
is concise, accurate, and easy-to-use. 03497-90020 Installation and Service Manual $25 $50
Because these manuals are signific- 03497-90021 Plug-in Assemblies and 3498A $25 $50
antly improved over the prior edi- Extender Service Manual
tions, we thought our customers
would want to hear about the special OPERATING, PROGRAMMING AND
limited time offer to purchase any CONFIGURATION MANUAL (03497-90019)
one or all of them at half price. We This 665 page manual contains operating, programming and configuration
will soon be mailing out a letter to information for the 3497A mainframe, for its plug-in assemblies (Options 010
nearly 1000 customers who have through 140) and for the 3498A Extender.
returned the "pink card" requests for MAINFRAME INSTALLATION AND
manual information. SERVICE MANUAL (03497-90020)
This manual contains installation and component level maintenance infor-
So look for your card in the mail, or
mation for the 3497A and the optional DVM (Option 001).
if you just want to buy a great man-
ual, get your order in soon. These PLUG-IN ASSEMBLY/3498A EXTENDER
new manuals are certainly a n asset SERVICE MANUAL (03497-90021)
to the 3497A and we are sure that This manual contains component level maintenance information for all
you will be pleased with them. Con- plug-in assemblies (except Option 140 which is unserviceable) and for the
tact your local H P office for details. 3498A Extender.
New Service Notes Provide Aid in Troubleshooting and Service
Calibration and Troubleshooting for Random This condition can be traced to one of
Troubleshooting for the Intensity Level Changes several different causes. The first
1980A/B Oscilloscopes This troubleshooting tip is for step is to monitor the unblanking
1980A/B Oscilloscopes with serial gate output with a n oscilloscope,
numbers prefixed 2126A and below. then the CRT grid and cathode volt-
This issue of Bench Briefs lists sev- ages with a high voltage probe and
e r a l service notes for t h e Does your instrument show a ran- meter. Should a change in any of
HP 1980A/B Oscilloscope Measure- dom brightening of trace intensity? these levels coincide with the inten-
ment System that will help you save (The character display may or may sity level change, it would indicate a
time and money, and improve the not be affected.) Does a front panel circuit problem. Trace the problem
reliability of your Hewlett-Packard key closure seem to correct the trace to the source of the shift in level and
product. intensity level? correct.
WWW.HPARCHIVE.COM MARCH-MAY 1983 BENCH BRIEFS 7
If the gate or CRT grid and cathode time consuming than needed. Many form simple adjustments to correct
levels remain constant during inten- technicians misunderstand (through for the deviation. These adjustments
sity shifts, it may indicate that one no fault of their own) the intent of are stored in the HP 1980 in non-
of the CRT grid-to-cathode protec- the service manual calibration pro- volatile memory (RAM) as "cal fac-
tion neons (A2V1 or A2V2) is oscil- cedure. Due to the way service man- tors." The internal processor re-
lating. To verify this condition, lift uals are structured, technicians are trieves these numbers and uses
one end of either neon from the led to believe that all adjustments them in formulas that convert them
board and look for trace intensity must be checked at each calibration. back to analog voltages t h a t are
level changes. If the problem dissap- This is not true. Typically, a total used for positioning, balance gain,
pears, replace both neons with HP hardware calibration procedure is sweep timing, etc. The RAM is bat-
PIN 2140-0013. Refer to service note necessary only after a major over- tery protected when the power is off.
1980AlB-13 for configuration haul, or a repair affecting power The numbers are also protected from
instructions. supply levels, or a CRT replacement. being altered by a switch. Only
If lifting the neons did not cure the Many adjustments relate only to the when this switch is i n the non-
problem, the CRT itself is suspect. loading effects of the CRT and do not protected position can the software
need to be checked unless the CRT is calibration routine be entered t o
New and Improved User replaced. change the numbers.
Calibration Procedures This procedure and the HP 1980
The precision signal source can be
service manual adjustment section
Service Note 1980AlB-14 is offered an external one traceable to NBS; or
are structured to direct you to only
as a supplement to the Operating if less accuracy is acceptable, the
those adjustments necessary after
and Service manual and is recom- oscilloscope contains convenient
specific repairs. Test equipment internal peak-to-peak and timing
mended for all serial numbers.
requirements are the same as any capabilities.
Calibrating the HP 1980 Oscillo- 100 MHz oscilloscope with the ex-
scope Measurement System is bro- ception of a counter necessary t o Software calibration may be accom-
ken down into two different proce- check the processor oscillator. plished a t any interval the user
dures. The first procedure, called deems necessary. Under normal
hardware calibration, is similar to Software Calibration operating conditions the specifica-
calibrating a standard oscilloscope. Software calibration is an interac- tions should hold for at least six
The second procedure, called tive process between the operator months. If the user desires meas-
software calibration, or in the case of and the HP 1980 Oscilloscope. In urements to be better than specifica-
the HP 1980, Front Panel Cal, is en- simplified terms, you apply a known tions the calibration interval may be
tirely new. precision signal to the oscilloscope shortened. Best of all, this procedure
and observe the amount of deviation can be performed while the instru-
Hardware Calibration ment is in place without removing
on the CRT. Then, following a proce-
Hardware calibration is often more dure displayed on the CRT, you per- the covers.
Simplify Calibration on
Your Digital Voltage Source
On-Site Service Kits for For more information, use the form Do you own an HP 6129C, 6130C,
3455A and 3456A Digital at the rear of Bench Briefs and order 6131C, or 6140C Digital Voltage1
Service Notes 3455A-20B and Current Source? The "Polarity
Voltmeters Offset Switch" circuit has been mod-
3456A-1C.
Service kit 03455-69801 for the ified to extend the range of the Cur-
3455A and kit 03456-69801 for the rent Offset Adjustment.
3456A are designed to facilitate on- 5180A Waveform Recorder The Current Offset Adjustment is
site isolation and repair of failures Modifications to Improve used during calibration t o set the
in the 3455A and 3456A DVM's. Peformance minus 0.5 mA (binary units) or the
Each kit contains pretested printed minus 0.0 (BCD units) current offset
circuit boards that can be substi- Several Service Notes are listed in which acts as a reference for all out-
tuted for PC assemblies in a mal- this issue of Bench Briefs that rec- put currents. This modification
functioning unit. In addition to other ommend modifications to improve simplifies the "bit balancing" neces-
miscellaneous components, are performance and reliability of the sary during calibration.
diagnostic programs on tape 5180A Waveform Recorder. Use the For more information order the
cassettes that allow the user to test order form on the last page to order associated service notes listed on the
the DVM with several different HP Service Notes 5180A-2A, -3A, -4A, last page of this issue of Bench
controllers. -6A, -7A, -12 and -13. Briefs.
8 BENCH BRIEFS MARCH-MAY 1983
WWW.HPARCHIVE.COM
the good work. I hope to get the majority of my NOTE: They moved 3 years ago; the current
issues in the future. address is:
Sincerely, 3451 Church Street
Larry Long, Technical Support Evanston, IL 60203
Lanier Business Products, Inc.
2. Publication IPC-CM-770B has 116 pages,
Many readers receive their copy at home. Then, cost is $10.00 to members and $20.00 to
after reading it, bring it in and route it to non-members.
Missing BB copies interested individuals at work.
3. I find every issue of Bench Briefs informa-
Editor: tional and beneficial, keep up the good
The IPC has moved work and continue its publication.
I have been receiving the Bench Briefs publi-
cation for approximately the past three years. Editor: Bernard H. Serota
Evidently, they are also quite popular with Philadelphia Naval Shipyard
other individuals in my ofice since I often do Subj: Conformal Coatings, comments
not receive various issues. I did receive the Ref: (a) Bench Briefs, Jan-Feb 1983 issue Thanks for the input Bernard. My book is
January-February issue, and was very in- dated 1979 so I should have guessed that they
terested in getting information on the printed 1. On page 3 of reference (a) you s t a t e may have moved.
circuit board repair article that appeared in "IPC-CM-770B" "Guidelines for Printed
the July-October 1982 issue. Board Component Mounting" obtained More on addresses
from:
I have not received any of the 1982 issues. If Many readers have requested more informa-
you have back copies of those, I would ap- The Institute for Interconnecting and tion on the products referenced in the Printed
preciate any of them you have on hand. I Packaging Electronics Circuits Circuit Board Cleaning article in the July-
enjoy reading your publication and get a lot of 1717 Howard St. October 1982 issue. Here are the company
valuable information out of it. Please keep up Evanston, IL 60202 names and addresses.
Description Mfr. No. Mfr. Name HP Part No.
'"1 Low static, Solder sucker, AS 196 Soldapullt Edsyn Inc.
15958 Arminta St.
8690-0227
Red. t i D s Van Nuys, CA 8690-0253
~~
Solder, RMA (rosin mildly active) RMA P2 Alpha Metals 8690-0098
63/37 lead/tin .032 dia. 1001 South Lindwood Ave.
Santa Ana, CA 92705
solder, RA (rosin active) 60/40 RA P3 Alpha Metals 8690-0027
leadkin .050 dia. 1001 South Lindwood Ave.
Santa Ana, CA 92705
Gen. purpose solvent MS-180 Freon TF 8500-0232
Miller-Stephenson
1001 East 1st
Los Angeles, CA 90012
Contact cleaner and protector Cramolin Red Caig Laboratories 6010-0491
FSN-6850-880-7007 P.O. Box J
Escondido, CA 92025-0051
No noise Electronic Chemical Corp. 6030-0063
P.O. Box 35
Guttenberg, NJ 07093
Foam-tipped swab NA NA 9300-0767
Lint-free industrial woven cloth TX 309 Texwipe Co. 9310-0039
650 East Crescent Ave.
Upper Saddle River, NJ 07458
Reliasolv No. 564 Alpha Metals 8500-1803
1001 South Lindwood Ave.
Santa Ana, CA 92705
Flux remover MS-19OHD Miller-Stephenson 8500-0735
-3 1001 East 1st
Los Angeles, CA 92025-0051
v-200 Baron-Blakeslee 8500-0735
2001 North Janice Ave.
Melrose Park, IL 60160
MARCH-MAY 1983 BENCH BRIEFS 9
WWW.HPARCHIVE.COM
1332A DISPLAY 3466A MULTIMETERS
1332A-98. All serials. Preferred replacement for 3466A-6A. Serials 1716A14170 and below. New true
A2R90 astigmatism potentiometer. RMS converter improves AC accuracy.
3466A-12. Serials 12061 and below and serials
1335A X-Y DISPLAY 121 10-12146. Improved common mode rejection of
1335A-5A. All serials. Recommended CRT change to input amplifier.
improve performance. 3466A-13. All serials. Recommended low noise input
1335-1 1A. All serials. Storage CRT appearance amplifier.
specification.
1335A-13A. All serials. Replacement part number for 3468A MULTIMETERS
the model 1335A Mother Boards. 3468A-1A. Battery retrofit kit installation for battery
retrofit kt P/N 03468-68701.
1345A X-Y DISPLAY
Need Any Service 1345A-1A. Serials 21 12A00475 and below. Loose
post accelerator leads.
3490A MULTIMETER
3490A-86. Serials 1211AI2555 and below, and se-
Notes? 1740A OSCILLOSCOPE
rials 1529A03905 and below. Recommended re-
placement for power supply capacitors C101
1740A-20A. Serial numbers as follows: "A'-Prefix through C107.
2226A and below, "G" Prefix-all serials, "J"
They're free! Prefix-all serials. Correcting delay line caused low 3496A SCANNER
bandwidth and slow risetime. 3496A-7A. Serials 2137A00990 and below. Eliminat-
Here's the latest listing of Service ing fixture enable arc at paddle pins.
Notes. They recommend modifica- 1741A OSCILLOSCOPE
1741A-13A. Serial numbers as follows: "A-Prefix 3724A BASEBAND ANALYSER
tions to Hewlett-Packard instru- 2017A and below, "G" Prefix-all serials, "J" 3724A-2. Serials 2217U-00161 and below. (Note, se-
Prefix-all serials. Correcting delay line caused low rials above 2212U-00156 will already have
ments to increase reliability, im- bandwidth and slow risetime. 03724-60123 fitted and +12V track cut on 3725A
prove performance, or extend their A18.) Power supply improvements to prevent in-
1742A OSCILLOSCOPE strument hang-ups at switch on.
usefulness.
1742A-5A. Serials 2021 A and below. Correcting delay
line caused low bandwidth and slow risetime. 3730A DOWN CONVERTER
Use the order form at the rear of 3730A-6. Serials 1541 U-00441 and below. Preferred
1743A OSCILLOSCOPE replacement for mixer 0960-0174.
Bench Briefs, to order free of charge, 1743A-6A. Serials 2236A and below. Correcting delay
individual Service Notes document- line caused low bandwidth and slow risetime 3746A SELECTIVE LEVEL MEASURING SET
3746A-3. All serials. Retrofit procedure for opt. 015/
ing several instruments. 1744A OSCILLOSCOPE 016 channel impairments.
1744A-7A. Serials 2109A and below. Correcting delay 3746A-4. All serials. Retrofit procedure for opt.
line caused low bandwidth and slow risetime. 012-tracking generator.
If you would like to purchase large 3746A-5. All serials. Retrofit procedure for opt. 011-
quantities of Service Notes covering
r
1745A OSCILLOSCOPE group filter.
a wide range of instruments, or if 1745A-1. Serials 2248A and below. Correcting delay
line caused low bandwidth and slow risetime. 3763A ERROR DETECTOR
you desire a complete history of all 3763A-7. All serials. Preferred replacement for A1 4
1746A OSCILLOSCOPE IC27 (1 820-1 755).
Service Notes documenting all 1746A-1. Serials 2229A and below. Correcting delay
changes t o your instruments, line caused low bandwidth and slow risetime. 3779A/B PRIMARY MULTIPLEX ANALYSER
3779A-22A. Serials 2005U and below. Update of
Hewlett-Packard offers a microfiche software. Supercedes 3779A-5 and 3779A-8.
1980A/B OSCILLOSCOPE
library for a modest, one time 198ONB-12. 1980 serials 2209A and below; 19806 37798-23A. Serials 2005U and below. Update of
software. Supercedes 37798-5 and 37796-8.
charge, there is a microfiche sub- serials 2144A and below. Modification to prevent
CRT arcing.
scription service available t h a t 198OAIB-13. 19808 serials 2126A and below. Trou- 3780A PATTERN GENERATOWERROR
automatically updates the library on bleshooting tip to isolate cause of random intensity DETECTOR
level changes. 3780A-27. All serials. Retrofit of option 101.
a quarterly schedule. 198OAIB-14. All serials. Manual supplement describ-
ing calibration procedure. 37826 ERROR DETECTOR
37826-2. Serials 221811-00266 and below. Preferred
The part numbers for the microfiche 3060A CIRCUIT TEST SYSTEM replacement for A32 assembly.
library and subscription service are: 3060A-50A. All serials. Improved field diagnostic of
3785A/B JllTER GENERATOR AND
analog relay failures.
3060A-53. All serials. Improved readings of BTL RECEIVER
Library of "trans" statement using the 3455A. 3785A-6. Serials 22261100237 and below. Prevention
of possible damage to A35U27.
Service Notes- 5951-6511 3421A DATA ACQUISITION/CONTROL UNIT 3785A-7. All serials. Preferred replacement for A30
Subscription service- 5951-6517 3421A-2. All serials. 44462A actuator/multiplexer Q9 and Q10.
jumper configuration. 37856-5. Serials 222811001 56 and below. Prevention
3421A-3. All serials. Transfer restrictions of boards of possible damage to A35U27.
Contact your local HP Sales Office between the United States and Canada to Europe. 37856-6. All serials. Preferred replacement for A30