Two engineers at a white bench, one holding a bare copper board up to a task lamp while the other annotates a drawing, calipers and drivers beside them

Trust layer · engineering & solutions

Engineering & solutions team

The engineer who reviews your file signs the assessment. Commercial terms ride with the same contact, so nothing is lost between two desks.

IPC-A-610J · March 2024 Class 2 · Class 3 DFM review, 24 h target

01Who writes the assessment

One engineer signs it. Not a sales desk.

Service line 4 of 6Written report, not advice

A microscope eyepiece, a sealed bag of teal granules with a blank label and an unbranded white carton in a row on a pale bench — Fig. A Samples, optics and courier boxes — the objects a file becomes.

An engineer's hands at a bench under an inspection lamp, working on a board with tweezers beside an open laptop — Fig. B The bench your file is read at, before any price is discussed.

The assessment is written by the engineer who reviewed the file.

Sign-off Reviewing engineer Name and date on the report. A sales contact carries the commercial thread and authors no technical conclusion.

Factory side Process engineer The counterpart who can change the line, not an account manager.

Unverified Written as such Anything unconfirmed is stated as not verified yet, with the date it will be.

What the assessment service covers

02Five roles on a live order

Nobody here is a name on a card.

Roles, not invented faces

Macro view of a circuit board edge showing copper planes and plated through-holes

ENG-01

Export engineering

Owns the file from first read to shipment.

StackupDFMClass decisionTest plan

Signs the written assessment

Rows of SMT placement machines and feeder banks receding down a bright assembly line

ENG-02

Process engineering

The counterpart who can move a line.

TolerancesFinish calloutsChange notices

Answers in Chinese, in writing

Four finished rack-mount network switches in a row with closed blank faceplates

ENG-03

QC lead

Writes the plan that releases the balance.

ISO 2859-1Level IICorrective action

Books the third-party slot

A shelf of finished consumer devices including tablets, monitors and a compact robot

ENG-04

Sourcing

Matches your product to a site in the network.

24 sites5 groupsCapacity check

Prices it against your quote

A single visitor in a white coat walking the aisle of a bright assembly hall between rows of machines

ENG-05

Shenzhen host

Runs the two days you spend here.

Invitation letterItineraryInterpretation

Meeting schedule included

03What the written assessment contains

Six deliverables, each tied to a standard.

IPC-A-610JIPC-7095UL 62368-1

A production panel of identical green circuit boards held in a white inspection fixture — Stackup Reviewed against the fabrication envelope.

Close macro of a circuit board edge showing stacked copper planes and plated holes — Class Class 3 acceptance adds 20–40% over Class 2.

A dimensioned engineering drawing sheet with a pencil and a pair of dividers laid over it — Open questions Answered in writing before the quote is final.

Deliverable · what each item states
Item	What it states
Stackup & DFM	1–58 layers, 0.1 mm trace and space, 0.15 mm drill, 1–8 oz outer copper
Class decision	IPC-A-610 class 2 or 3, and its cost step
BOM review	Second-source and obsolescence notes, priced at the re-order
Compliance gaps	UL 62368-1, IEC 62109-1/-2, FCC Part 15, RoHS, CE Declaration of Conformity
Test plan	SPI and AOI, X-ray voids to IPC-7095, ionic cleanliness at ≤1.56 µg NaCl eq./cm²
Open questions	What the factory must answer in writing before the quotation is final

04Third-party verification

How a sample reaches an accredited laboratory.

Report in 24–48 h4 h expeditedPSI $199–320 / man-day

Hands closing digital calipers around a machined part beside a clipboard with a blank inspection sheet — Fig. C Drawn from the production lot.

A clipboard holding a blank ruled form with a pen and a teal sticky tab, photographed from above — Fig. D Every result lands as a written line.

Step 1 Selected from the lot Sealed, photographed and logged against the lot number.

Step 2 You pick the laboratory SGS, TÜV, Intertek, Bureau Veritas or UL — or nominate your own.

Step 3 It reports to you The buyer pays the inspection body directly, keeping the conclusion independent.

Step 4 Back into the file Corrective action becomes a line in production follow-up, not a phone call.

The inspection fee never passes through us. A factory audit runs $220–458 per man-day.

05Engineers, sales and the language bridge

Two registers, one file.

Service line 2 of 6Change notices in both directions

Two pairs of hands over a technical drawing, one pointing at a dimension with a pen — Fig. E Drawings, stackups and BOM queries carried in Chinese by the same team.

An SMT line seen down its length, pick-and-place machine and reflow oven with boards on the conveyor — Fig. F Our own line: the engineering backstop.

Engineer owns The technical file Stackup, impedance, materials and finishes, class and acceptance criteria, derating, cleanliness, test coverage, failure analysis.

Commercial owns The commercial thread Price, Incoterms, lead time, payment terms, tooling ownership, shipping schedule.

When a technical answer changes the price — a tighter class, a different finish, an added test — it becomes a line item.

Drawings Stackups BOM queries Change notices, both ways

The language bridge as a service

06What we need from you

Gerber and BOM start it. The rest sharpens it.

Acknowledgement, one working dayOpen questions in writing

A dimensioned technical drawing flat on a pale bench with a thin pen and folding dividers — Files Gerber or ODB++ with the fabrication drawing.

A finished rack server power supply module with a perforated intake face and a gold edge connector — Not a board Send the finished-product spec and the interface requirements.

The file set What to attach Gerber, BOM with manufacturer part numbers, stackup and impedance targets, target class, first-order and annual quantities, destination market.

What happens next One working day The engineer who acknowledges the file owns it. One network site publishes a 24-hour DFM review as standard.

Send us your file Our own PCB & PCBA factory

07Start

An engineer replies, not a chatbot.

Name the category or attach the file. You get a written technical assessment.

Recorded. An engineer will reply.

From eric@dfshk.cn, with the assessment attached.

How quality is controlled eric@dfshk.cn · +86 152 3512 7440