1. What type of squeegee do you use? Rubber or
metal one?
﹛
Both types used, Rubber squeegee is for manual
appliance while metal one for semi-automatic solder
pasting.
﹛
2. What type of solder paste
do you use?
1) Solder paste (non-lead-free):
63/37; Brand: KOKI (Japan); Specification &
model:SE48-M 955; FLUX: 10%.
2) Solder paste (lead-free):
Brand: Senju (Japan), Model: M705; Alloy of tin
(96.5%), silver (3.0%) and copper (0.5%) ;
3) Require credited solder material vendor to offer
samples and related specifications for perusal. Set
the temperature profile of solder bath as per
specification. Finally undergo a test on the sample
and review the result.
﹛
3. How about pick-up and
placement of the mounter? How do you make sure you
get the right mounter?
mounter
-- On-The-Fly-Vision System
-- Mounting speed: 0.165 sec/chips
-- PCB size: min. 50x80mm to max.457x356mm,
thickness: 0.3mm to 4.0mm
-- Component applicable: 0402 to 25mm (L) x 20mm
(W); 6mm max height;
-- Mounting accuracy: +/-0.05mm chips +/-3 sigma;
+/-0.30mm SOIC etc +/- sigma;
We choose the mounter of well-known
brand in a SMT specialist , Fuji in Japan, with a
"On-Fly-Vision System" to ensure accurate placement.
﹛
4. Is there any visual or auto
inspection? Will the operators attempt to shift
"misplaced" components?
(actually a bad idea in most
cases, many parts will self-align during soldering).
1), Currently , visual inspection is adopted and our
operators would attempt to shift "misplaced"
components. Also we use the ICT (In-circuit Tester)
to inspect the processed PCB. And we have been
planning to introduce the facilities to carry out
the automatic inspection.
2), The upcoming SMT chip mounter due to arrival on
Sep. 1, 2005: Brand : FUJI(XP-143E),
Mounting speed: 21,000 / hour; Mounting capability
ranges from the min.01005 to the max. 25*20mm.
﹛
5. Reflow oven specification?
Hot air or nitrogen?
﹛
Reflow oven (hot air)
Brand: HELLER (U.S.A.); Model: 1809EXL;
Heating zones: 9 zones above/ 9 zones below ;
Cooling zones : 2 zones
Temp. control precision: ±0.1℃;
﹛
6. What are your capabilities
on lead-free soldering?
1) The following machines ,
equipments and tools have been introduced to carry
out the lead-free production,
Reflow Oven (HELLER-U.S.A), Wave Soldering Machine,
High precision SMT mounter (FUJI -Japan),
Soldering irons and other tools.
2) The lead-free project has been underway since
2003, We've assigned engineers and technicians to
attend various trainings, lectures and seminars on
lead-free technology.
3) Samples will be inspected now and then.
﹛
7. What are your ESD control
procedures?
1) Operators have trained on ESD
Control as per IPC training course.
2) Wrist-strap is a must in process, which is
checked before work every morning.
3) Proper grounding device is in place;
4) Grounded smocks and gloves are in place if
necessary. Also, we use the special anti-static
trays to hold products and soldering iron. All the
procedures contribute a lot to prevent risk of ESD.
﹛
8. What are your moisture
control procedures?
Thin components, e.g. the LAN
controller, will absorb moisture from the air, and
crack during reflow soldering if too much moisture
was absorbed by the epoxy. This usually results in
long term failures.
1) Our SMT room is air-conditioned for the whole
procedure from solder-pasting to chip-mounting.
2) The chip component is sealed in plastic reel with
anti-moisture chemicals.
3) One of warehouse is air- conditioned to reduce
the humidity below 60%.
﹛
9. What kind of wave soldering
machine do you use? Spray or foam fluxer?
We use double wave soldering
machine and spray fluxer.
﹛
10. How will you do selective
wave soldering?
1) Compare specifications of wave
soldering machines adopted by renowned companies to
confirm the requirements the machine could meet.
2) Make factory tours to review the performance of
machines.
3) Perform experiments -- wave solder PCB sample and
record the temperature profile. Send the temperature
profile to experts in Senju (lead-free material
vendor in Japan) to confirm its suitability for
lead-free soldering.
