EMS–TRADE Electronics export trading
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Two pairs of hands over a technical drawing, one pointing at a dimension tick with a pen

Service 02 · language bridge · engineering documents

Your drawings and changes,
carried in Chinese by engineers.

When your specification leaves your desk, the question is whether what arrives at the factory is still your specification.

Send us your drawing and BOM What you receive
Where it breaks
3
Failure points: a tolerance stated twice, an unspecified class, a late change
Class 3 vs Class 2
20–40%
Assembly cost added by a class change, at 8–15% defect against 2–5%
Ionic contamination
1.56vs 0.78
µg NaCl eq./cm² at Class 2 and Class 3 — a limit you can write down
Inspection report
24–48 h
Standard turnaround, expedited to 4 hours when a vessel is waiting

01The fear

Communication is where
foreign vendors lose.

3 failure pointsall documentary
Two pairs of hands over a technical drawing, one pointing at a dimension tick with a pen FEAR-01

The attack is on the record

A competing manufacturer's own testimonial says good communication is where they beat Chinese vendors.

not a factory claima layer claim
A single technical drawing sheet on a pale surface with a pen, folding dividers and one teal sticky tab FEAR-02

A tolerance stated two ways

One callout on the drawing and a different one in the purchase order. Nobody notices until the parts are measured.

drawing vs POrejected batch
A blank unmarked form on a clipboard with a pen, abstract ruled lines and empty tick boxes FEAR-03

A class nobody specified

Leave the workmanship class unstated and it defaults to whatever the factory uses, not what your product needs.

unstated = defaultfound at inspection
A finished populated board assembly for a power supply lying flat on a white engineering bench beside a digital caliper FEAR-04

A change that arrives late

A change reaching the line after the panel is etched is a scrapped batch plus a re-quote.

change timingscrap, not rework

02Deliverable · the bilingual pack

A numbered pack,
in both languages.

6 documentsmatched revision numbers
A blank unmarked form on a clipboard with a pen, abstract ruled lines and empty tick boxes
DOC-01 Chinese revision pack. Your drawing set, BOM and specification, issued with a revision number matching the English original one-for-one.
A single technical drawing sheet on a pale surface with a pen, folding dividers and one teal sticky tab
DOC-02 The query log. Every factory question with an owner, a date and the answer — nothing resolved by a phone call nobody recorded.
A close view down one SMT line with pick-and-place heads and feeder reels in strict alignment
DOC-03 The workmanship statement. Written into the purchase order in both languages, naming the acceptance document and the class — never an adjective.
A technical drawing flat on a bench with a thin pen and folding dividers beside it
DOC-04 The change notice. What changed, who approved it, and what it does to price and lead time. Any BOM change re-opens the quotation.
An engineering bench under an inspection lamp with a finished board assembly, a magnifier arm and sample connectors
DOC-05 Meeting minutes. Both languages, after every technical call, circulated within 24 hours.
Two pairs of hands over a technical drawing, one pointing at a dimension tick with a pen
DOC-06 The Chinese original. It travels with the English version. You never receive a summary of what we said on your behalf.

03Why English alone fails

Five documents,
five different jobs.

IPC division of labourclass comes from your PO
A single technical drawing sheet on a pale surface with a pen, folding dividers and one teal sticky tab STD-01

Design

The layout and land-pattern documents live here, and they do not define what the factory must accept.

IPC-222XIPC-7351
A production panel of identical boards held in a white inspection fixture with gold pads and a teal solder mask STD-02

The bare board

Board requirements and bare-board acceptability are two separate documents, and quoting one does not invoke the other.

IPC-601XIPC-A-600M
A close view down one SMT line with pick-and-place heads and feeder reels in strict alignment STD-03

The soldering process

This is the process document — how the joint is made, not how it is judged.

J-STD-001JRev J, March 2024
An engineering bench under an inspection lamp with a finished board assembly, a magnifier arm and sample connectors STD-04

Acceptability

The document an inspector works from. Its own text says the user defines the class; the standard will not choose one.

IPC-A-610JRev J, March 2024
A finished populated board assembly standing on edge with a matte black heatsink and a row of connectors STD-05

Rework and repair

Rework has its own document. Writing “rework permitted” without naming it leaves the method to the line.

IPC-7711/7721DRev D, December 2023
Four finished rack-mount network switches in a row with closed faceplates and empty port cages STD-06

X-ray is not in the acceptability document

IPC-A-610J §1.1 provides no cross-section or X-ray criteria; BGA void judgement belongs to IPC-7095.

§1.1 excludes itIPC-7095 governs voids

04Mechanism · five steps

How a change
actually gets carried.

5 stepsnothing confirmed verbally
A single technical drawing sheet on a pale surface with a pen, folding dividers and one teal sticky tab STEP 01

The change arrives

Any form is acceptable: a marked-up drawing, an email line, or a revised BOM row.

Two pairs of hands over a technical drawing, one pointing at a dimension tick with a pen STEP 02

It is restated against the current revision

The factory confirms in writing. A verbal “OK” is not a confirmation.

A blank unmarked form on a clipboard with a pen, abstract ruled lines and empty tick boxes STEP 03

The impact is priced

A component substitution can move the class, and a class change moves assembly cost 20–40%.

A close view down one SMT line with pick-and-place heads and feeder reels in strict alignment STEP 04

Everything reissues together

Revision pack, query log and purchase order carry one new revision number, so no document is stale.

A finished populated board assembly standing on edge with a matte black heatsink and a row of connectors STEP 05

The re-quote comes before the restart

If the change is yours after release, the revised price is issued in writing first.

05Inputs · what we need from you

Four inputs,
and the pack can open.

4 inputsthen a revision pack
A single technical drawing sheet on a pale surface with a pen, folding dividers and one teal sticky tab IN-01

The current revision

Your drawing set as it stands today, with the revision letter it carries.

A blank unmarked form on a clipboard with a pen, abstract ruled lines and empty tick boxes IN-02

The BOM

Manufacturer part numbers, approved alternates, and anything you will not substitute.

A dim clean room bench with an oscilloscope, a bench power supply, a board assembly under a magnifier and a sealed sample bag IN-03

The acceptance you want

The class, the acceptance document and the inspection level for the purchase order.

A technical drawing flat on a bench with a thin pen and folding dividers beside it IN-04

The change history

What has already been changed, by whom, and whether the line has been told.

06Where it fits

Language removes ambiguity.
Inspection verifies the result.

quoted separately6 services

No partner factory is named on this page. Naming one would read as an endorsement; every partner is listed on the network pages.

07Start

Send us your drawing and BOM.

Send the current revision. We will say what the factory can misread in it, and write the class into the order.

Recorded. An engineer will reply.

Written technical assessment, from eric@dfshk.cn.

Book a factory visit eric@dfshk.cn · +86 152 3512 7440