Why a sheet, not a question. On the measurement behind this page — the laminate layer — two of sixteen profiled Chinese PCB plants name a laminate grade they actually buy, and none names the mill's plant or a date code. A one-line question (“what laminate do you use?”) gets a one-line answer, usually the word “FR-4”. A request sheet gets either a specification or a refusal, and both are information.
How to use it. Paste the block below into the RFQ email, after your stack-up drawing and before your commercial questions. The reply quality is itself a test: a factory that answers seven of eight items in specific terms has run your kind of board before; one that answers all eight with adjectives has not, or does not want to.
What it deliberately omits. Prices, dielectric constants and loss tangents. The first belong to your negotiation; the second belong on the mill's datasheet, which is one of the documents you are requesting. This page reprints no datasheet numbers for the same reason the quotation page reprints no prices — a figure that is right this quarter is wrong the next, and a number without its source is not evidence.
MATERIAL REQUEST — please answer per item, in writing, with the quotation
1. For each laminate layer and prepreg: mill name, exact grade
designation (e.g. "S1000-2M", not "FR-4"), and Tg by DSC.
2. Which producing plant of that mill supplies your facility.
3. Is that grade on allocation today? Date it was last confirmed.
4. Price the SAME board twice: on the quoted grade, and on one
alternative grade you have qualified. Two lines, two prices.
5. Price validity window, and who carries a mill price increase
between quotation and shipment — one sentence, in the quote.
6. First shipment: photograph of the mill label with grade and
date code, on the pallet, before cutting.
7. Sample incoming-inspection record for that grade (redacted OK).
8. If HDI: which material family the line is qualified on, and
the named second source if that family is unavailable.
Item 4 is the one that changes behaviour most. Asking for a second price on the same board does three things at once: it reveals whether the first quote was bottom-tier or mid-tier, it proves the factory can actually buy the grade it named, and it tells you what the upgrade costs before you need it.
Replies are not equally strong. Rank what comes back on five levels, and note that the top level is the only one that survives a change of purchasing manager on either side.
A specification. Matchable to the pallet, auditable after delivery, transferable to a second factory for a cross-quote.
What item 1 of the sheet asks for. Checkable against the mill's published datasheet; still leaves which plant, and which lot.
An exhibited board, a named build-up. The strongest evidence in this directory today: Jingming's 8-layer UAV board on Shengyi S1000-2M at TG170. One board is not a capability statement, but it can be re-ordered and compared.
“We use Shengyi and Wangling” — Wanyexing's entire material disclosure. Tells you the price band, not the material.
The level of twelve of the sixteen plants here, and of most first replies. Standard FR-4 to low-loss hydrocarbon is the widest cost range in the quotation, and it is all inside this word.
These are the designations that actually appear in this directory — either on a plant page or in the material a plant names. What each grade does electrically is on the mill's datasheet; request it (item 1) rather than trusting a summary, including this one.
| Designation | Mill it belongs to | Where it appears in this directory | Evidence level |
|---|---|---|---|
| S1000-2M | Shengyi (生益科技) | Jingming's exhibited 8-layer UAV board, at TG170 | Level 3 |
| Wangling (旺灵) | Wangling, a Chinese laminate maker | Wanyexing's base-material list, brand only, no grade | Level 2 |
| SJ7036N | Shengyi | Guangtian's stated capability, from company marketing | Level 1–2 |
| RO4350B | Rogers | Guangtian's stated capability, from company marketing | Level 1–2 |
| MW-3350 | Taconic | Guangtian's stated capability, from company marketing | Level 1–2 |
| IT-968 | ITEQ (联茂) | Named in this directory's high-layer page as an example of what to request — no plant here has published it | — |
| Megtron 6/7 | Panasonic | Same — an ask-for example, not a plant disclosure | — |
| “FR-4” / “aluminium-based” | a category, not a grade | Hong'an Xingsheng, Shengda Xinxing — and, in effect, everyone else | Level 1 |
Read the Guangtian rows twice. The only plant here that names three specific grades — including imported high-frequency material — is the one whose profile records active enforcement and a judicial auction. The grades are probably real; the disclosure is still marketing copy, at Level 1–2, and the plant is not one you should be qualifying. The measurement page has the details.
“FR-4 is FR-4.” It is not: standard, high-Tg and low-loss are different materials with different cost bases, and the difference is invisible in the word. A factory that says this is pricing the widest range in the quotation blind, or hoping you will.
“Material is subject to availability” — with no clause. Availability risk is real: the mill behind most named grades here sold 2.50 million m² more laminate than it produced in 2025, which is what a tight market looks like from the inside. But a warning without a pass-through rule is an option the factory holds on your price. Ask for item 5's single sentence.
“We use whatever is available.” For a digital board this may be an honest answer. For an HDI stack-up it is not acceptable: the HDI-grade segment is roughly 70% one supplier (on Prismark data — see the laminate layer), so “whatever is available” is a specific dependency the factory has chosen not to name.
A grade promised, no label photograph. The promise costs nothing; the photograph takes ten seconds on the pallet. The gap between the two is where substitutions live — and a substitution discovered at first article costs you a build cycle, not the factory.
“Certified laminate.” Certificates attach to factories and to management systems, not to sheets of material. A factory with an ISO 9001 number can still buy bottom-tier laminate. The material's own documents are the datasheet, the label and the incoming-inspection record — items 1, 6 and 7.
When a reply comes back with a grade on it, four checks fit in a coffee break, all free.
| Check | How | What a pass looks like |
|---|---|---|
| 1 · Does the designation exist? | Search the mill's own site or a distributor listing for the exact string (“S1000-2M”, “IT-968”) | A datasheet PDF with that designation and the mill's name on it |
| 2 · Does the Tg match? | Compare the reply's Tg (DSC) with the datasheet value | Same number, or a explained difference in method |
| 3 · Is the mill plant plausible? | The producing plant should be in a province with laminate capacity, not a forwarding address | A named site that appears on the mill's own contact page |
| 4 · Does the second price move? | Compare the two lines from item 4 | A different number — identical prices for two grades means one of them is not real |
If all four pass, you are talking to a factory that buys laminate deliberately. That is a better predictor of how your boards are built than anything on its website — including the ones in this directory.
Where these numbers come from: the laminate layer (2 of 16 name a grade; Prismark 2025 rankings; the mill's filing arithmetic). Where the sheet sits in the document chain: what a Chinese PCB quote actually contains (nine line items, six clauses) · the factory audit checklist (what to photograph at goods-in — the laminate racks are stop one) · verify a Chinese PCB supplier in 20 minutes (the checks that run before any of this). Process context: high-layer-count · HDI and any-layer.