Electronic Product Production and Manufacturing
From the 60s to 90s Electronic Manufacturing had
many manual operations. Even today and the future
small volume production and custom electronic
manufacturing use these methods.
60s and Earlier Electronics had Valve Tubes and
then the transition to semiconductors. Later ICs
made things much smaller. Embedded Systems and SMD
technology later shrunk thinks to pocket size
Inspection for Quality Control
It goes like this .... Technology and
Size in Volume of a Music Player with Radio in
Housing or Cabinet.
It was first a Huge Wodden Cabinet that would be
kept in the Living Room with a Valve Radio,
Turntable to play LP Records and a Spool Player
which was like a Large Tape Recorder.
The same thing now is a mp3 player and Radio that
can be put in your Shirt Pocket and you could move
around town too, all day long on a single charge.
||Chips or IC
||SMT ASIC SoC
First Inspect PCB for hairline shorts and cuts and
also traces of unwanted copper in the edges and
repair them. Also Check if all Drill holes &
Slots are proper size and PCB is Fitting in its
Place properly, This is because Drilling and Filing
should not be done after assembly as it causes
serious reliability problems.
in Axial and Radial Plastic Capacitors
Second populate all the resistors, Jumpers, Diodes
and Ceramic Capacitors these are tough components.
Then Insert all Transistors, LEDs, Displays,
Electrolytic Capacitors and IC s (Bases), Here care
should be taken not to overheat any component as it
may damage them. Lastly Solder Connectors, Relays,
Coils and Transformers which may require a high
wattage Iron, and Mechanical Reinforcements.
Precautions during Production
- Observe Polarity for Diodes, El-caps,
- Make sure of Pin 1 for IC s, Regulators,
Transistors and Mosfets before insertion.
- Avoid bases for ICs in production as these
fail on use.
- Make use of Electrostatic protection for CMOS
- When Cutting Leads use protective Goggles and
do it in a separate place as the cut leads fly
all over the place.
- Use Iso Propyl Alcohol (IPA) as de-greasing
agent on PCB.
- Water & Detergent wash is very good but
only if coils, Transformers, Relays are
hermetically sealed- Impregnated.
Use a Lacquer-Varnish or RTV rubber coat on both
sides of PCB including on the components to prevent
corrosion and also it helps maintain
Lead is a kind of poison, use gloves or wash hands
with soap after work is over. Flux, IPA, Thinner
Fumes can cause respiratory health problems. Work in
a ventilated area use Exhaust Fans and Open Windows.
Dispose of Metal, Plastic and Chemical waste
separately and well packed as these can contaminate
the environment and also cause Injury.
Published online around - Nov 1999
Some Pilot Production And
testing points when building electronic Projects
These are also important while prototyping and
Bread-boarding. These are things that i used to keep
telling youngsters when they are new in
manufacturing. This was when i was running my own
firm making industrial equipment and instruments.
I used to even give this and some other pages around
in printed format, it was composed with word on
windows 3.11. Then i realized it has to instructed
at every incident by example. Reading does not help
unless someone is passionate and enthusiastic about
Clean Rooms and Electronics
- Use 1% MFR 100 ppm resistors for all analog
- Use plastic or-and multilayer capacitors as
ceramics are leaky.
- Product should have minimum number of
- Nuts, Bolts and screws locked with adhesive so
that they do not slip and the product falls
- Potentiometers should move smoothly and not
get twisted, strained or locked due to cabinets.
- Use Strain relief for wires and strip the wire
and solder properly where required.
- Strip with a stripper do not use your teeth.,
Twist all the strands Tin the tip of the wire.
- After Tweaking and setting presets or trimpot
lock it with paint or varnish.
- Big Components should have large pads and
separate mechanical fixing to PCB.
- Acrylic and plastic can get blurred or
deformed with some solvents.
Do assembly of the card with a tested assembled 3D
reference. Even after all the care if the card does
not work, then after full assembly do visual
inspection in this order First keep both the cards
one reference and the other manufactured under a
If all the components were subject to incoming
inspection and testing. If still unit does not work
remove power and do cold check comparison with
reference unit in DMM 200K R range, if still problem
persists continue with power on testing and solve by
DMM or scope tests.
- Compare resistor color patterns one by one.
- Compare Electrolytic capacitors physical
appearance and POLARITY.
- Verify values of plastic and ceramic
- Cross-check Diode sizes and POLARITY. Verify
- Check IC and Regulator POLARITY and Exact type
number / brand
- Check Transistor, MOSFET, LED, POLARITY. and
verify display type No. and Polarity .
- Check for connector patterns and polarity and
- Reverse the card and Check for solder bridges
between close pins .
- Reverse card and Check for hairline shorts and
solder streaks due to bad PCB processing or
- Reverse card and check for hairline cuts or
pads lifted off card.
- Closely observe for dry solders on big
electrical parts (L and TX) a dry solder will
cover the pin and will be dull in shine.
- before calibration allow for product to warm
up for 15 mts.
Danger ! when DMM is in Ohms Mode, Even if one probe
touches 230 V, DMM is Gone, so take extra care while
doing this. test probe.
First written and printed offline in the Nineties.
Word on Windows 3,11 with Epson 24 Pin Dot Matrix
Printer., updated 2014.
Tables and Charts
How to Test Verify the Testing Methods Itself
Testing and Evaluation tools must have dynamic
decoys added into the device under test DUT or the
batch under test. In a Conveyor system, identifiable
(RFID) decoys must be artificially introduced every
100 pieces. This will constantly counter check the
Testing system and in not a One time operation. The
decoys should be defective or have a fault, a little
above threshold. This is caught by the testing
system. Even when the testing system ages or goes
out of calibration, this method can raise a alarm.
Even in software and text/data processing; this
method ensures database quality and software program
Work Culture and Discipline
Systematic and Meticulous work has its own Rewards.
An Engineers Notebook or a Hobby Experiments Log
Book can go a long way in making a Cauliflower out
of every Cabbage. (The credits of the Vegetable
Analogy goes to Mark Twain)
Keep Work Place Clean
Clean Tables and shelves every day before closing
office, Put Cut leads and Solder shots in a separate
cup to be accumulated and disposed later as these
are toxic. In this cup other irritants like staple
pins can be added and these can be clubbed in a
month and disposed off as one metallic bulk for
recycling. Never bring coffee or food to work area,
Keep a waste paper basket on your side.
Work carefully to avoid injury
When cutting leads hold the lead in the hand and cut
or it will fly all over the place. A piece like that
may land on another equipment and cause shorts or it
may go right into your eyes and cause blindness.
Lead and Isopropyl alcohol and other Chemicals may
be dangerous for health if handled carelessly. Do
not use fingers, and teeth as tools it is bound to
cause a injury to repent a lifetime. Be extra
careful with 230V AC and more so with 440V 1 tr 2mA
thru your heart and a weak streak of luck may be the
last experience you ever had. Do not press your Luck
Protect Desk or table surface
If you are cutting something let it not leave marks
on table, even adhesive stains should not deface
table, use a asbestos, hylam fiberglass, hardboard
surface which can be disposed once in a way. Before
working put two layers of news paper on the table
this prevents table from getting spoilt while
soldering and newspapers being hygroscopic (water
absorbent) they provide a natural antistatic surface
to protect CMOS Ics and are nonconductors for any
Live PCB kept on the paper.
Use tools and equipment's in a gentle manner
When you use weller Iron use it as a heat transfer
tool never use it for prying or crimping leads or
just pressing use pliers or other tools for that.
Document what you do and vice versa
Have a register in which you can make records of
what you did to solve a problem or what you learnt
while making an equipment this information is
valuable for the company to develop production
methods and also useful to your team to solve a
similar problem. Share abilities and skills with
fellow employees but don't share your company's
technology and database with any other company. When
you leave a company use only the abilities and
skills in that broad area to evolve as a
professional. - Engineers Notebook.
Hobby and Do it Yourself
It is by Hobby and DIY - Do it Yourself, Education
Starts even without books. Then you need to read to
enhance your abilities to Design your own.
In order to compensate or enhance your
education, you need to work at a small shop as an
apprentice even as a student, not for the sake of
project work alone. An Evening job at a factory or
a home mini workshop-lab is very essential for
obtaining the skills.
Published online around - Nov 1999
Solderman Talks - 1707 AD