The one thing to get right
A case is only useful if you can tell where your situation is the same and where it is different. Read each one for the constraint and the decision rule, not for the region — a European HDI line and an Indian HDI line fail at the smallest holes for the same reason, and a Bangladesh customs format problem is a documentation problem wherever it occurs.
How to read these cases
Each case is written to three parts, and the third part is the one that transfers. The situation describes the line, the board class and the symptom as the buyer described it. The constraint is the variable that turned out to control the outcome — which is frequently not the variable the buyer started with. The route is how the buyer satisfied itself that a change was real: which variable was held, what was measured, and on whose equipment.
Two rules keep a case honest. First, the symptom a buyer reports is a hypothesis, not a finding; drill breakage is reported as a drill problem far more often than it turns out to be one, and the cases reflect that. Second, a result only transfers if the conditions transfer with it. A stack height, a hole diameter and a bit-life position are part of the result, and a case that omits them has not earned the conclusion.
Where the mechanism behind a case is written up on its own, the case links straight to it rather than repeating it — the thermal side of microvia drilling is worked through in the ICD risk control guide, and the board-level selection logic sits in the HDI and micro-via drilling guide.
The six cases
A Bangladesh electronics maker: supply that lapsed, and was won back
A maker with in-house PCB production running a multi-year backup board relationship through a procurement pause, and the documentation-format problem that had to be solved before orders could resume on a normal cycle.
Read the case →A European factory working drill breakage on microvia layers
An HDI and multilayer plant running microvias at the smallest diameters, where new drills and new parameters had already been tried — and the entry material turned out to be the variable that had not been isolated.
Read the case →A substrate manufacturer qualifying high-end backup boards
A high-reliability substrate producer qualifying a second supply base through a formal gate — flatness and cleanliness specifications, batch consistency across years, and the documentation set the process required.
Read the case →An India channel partner consolidating a multi-brand group
A technology partner representing several PCB manufacturers with different specifications, working out where one stack can serve many factories and where a plant genuinely needs its own grade.
Read the case →An Indian manufacturer scaling HDI against batch variation
A plant adding HDI capacity where the bottleneck was not capacity but consistency — flatness and moisture behaviour varying between deliveries while the process was being pushed harder.
Read the case →A Singapore partner holding a gauge for semiconductor packaging
A trading partner carrying a thickness tolerance on behalf of a downstream assembly customer, where the constraint is holding the gauge through a long route rather than meeting it at the mill.
Read the case →Find the case closest to your situation
Pick by the constraint, and accept that more than one may apply — most buyers arrive with a symptom and a deadline, and the symptom is usually attached to the wrong layer. The table routes from what you are observing to the case that turns on that variable.
| If your situation is… | Read | Because it turns on… |
|---|---|---|
| A qualified material became unavailable, or a supply relationship lapsed and you need it back | The Bangladesh supply case | Continuity and documentation readiness rather than specification |
| Breakage or positional error concentrated on the smallest holes, with parameters already reviewed | The European microvia case | Isolating the entry layer from the bit and the program |
| First-time qualification, and paperwork is the gate rather than the sample | The substrate qualification case | Specification proof, batch consistency and the document set |
| Several plants or sub-brands on different specifications and you want fewer | The India channel case | Where a common stack is valid and where it is not |
| Capacity is going up and consistency is going down | The Indian HDI scale-up case | Delivery-to-delivery variation as the bottleneck |
| You have to hold a tolerance on behalf of an end customer further down the route | The Singapore partner case | Gauge control across a trading relationship |
If none of the six matches, the situation is probably not yet a material question — work it through the function of the entry board and the role of the backup board first, because a case only helps once you know which layer you are asking about.
What the cases have in common
Read together, the six cases point at the same short list of variables. None of them is exotic, and none of them is the price of the board.
- Consistency outranks the headline specification. Four of the six cases turn on delivery-to-delivery variation rather than on a datasheet figure. A grade that meets its tolerance every time beats a better-sounding grade that meets it on average.
- The stack has to close evenly, and moisture is what stops it. Flatness and dimensional state at the point of use appear in the scaling case, the qualification case and the trading case. The storage and seasoning side is on the moisture control guide.
- Documentation is a supply variable, not an afterthought. Two cases stalled on paperwork rather than on material: a customs format that not every supplier can produce, and a qualification gate that needed a specific document set. If your market or your qualification process has a document requirement, raise it before the sample.
- The failure is usually attributed to the wrong layer. The microvia case and the scale-up case both began as tooling or parameter investigations. Attributing a symptom correctly, before changing anything, is the single practice that saves the most time across these cases.
- Total cost is not the board price. In the high-volume and multi-plant cases the decision was driven by scrap, rework and downtime rather than by unit price, which is why the multi-plant case ended with a smaller grade list rather than a cheaper one.
The supplier-side process that keeps those variables under control — sampling, batch records, change notification and the document families — is described end to end under the qualification and supply process.
What we will and will not publish
We write about customers only within limits that we would accept if the roles were reversed, and it is worth stating those limits plainly because they also describe what a case can prove.
- No customer names without written permission. A PCB manufacturer's material list, yield and stack design are commercially sensitive. Cases are therefore identified by region, board class and plant scale, which is enough to make the situation recognisable to a peer and not enough to identify the buyer.
- No measured results we did not measure ourselves. Yields, CpK values and breakage counts in these cases were measured by the customer on the customer's equipment and coupon positions. We do not restate them as our own figures and we do not publish them here.
- No certification claims inside a case. Whether a customer's own qualification process ran under an NDA, a quality agreement or an internal standard is a fact about their process, not a credential of ours. Where a buyer needs a document, we supply the document and the buyer's own auditor decides what it is worth.
- No case that cannot name the variable. A case where several things changed at once, or where the improvement was never isolated, would be a story rather than evidence — and it would not help you decide anything.
If you want to talk to a reference in your own region, ask on the sample and quotation request and tell us the market and the board class; whether a reference is available depends on the customer, and we will say so rather than leave it open.
Questions buyers ask
Why are the customers in these case studies not named?
Naming a customer requires their written permission, and most PCB manufacturers treat their drilling materials, their yields and their stack designs as commercially sensitive. Each case is written by region and by scenario instead, which is enough to make the situation usable without disclosing who it was. Where a customer has agreed to be quoted publicly, that is a separate arrangement.
Do the case studies include measured results?
No numeric outcome is published on this hub. The figures a buyer would want — measured CpK, breakage counts, yield before and after — belong to the customer and were measured on the customer's own equipment. What the cases transfer is the part that is genuinely general: the failure signature that pointed at the material layer, the variable that turned out to matter, and the qualification route the buyer used.
Which case applies to my situation?
Pick by the constraint rather than by the region, using the routing table above. Supply continuity, positional accuracy at the smallest holes, documentation-led qualification, multi-plant consolidation, batch consistency on a scaling line and tolerance held through a partner between them cover most arrival reasons.
Can we reference your material in a customer-facing qualification document?
Yes, and the route is the one the substrate case describes: start from the technical data sheet for the exact grade, confirm the tolerance you need against it, and ask us for the drawing and the storage conditions in writing. If your qualification process requires a signed quality agreement or a business-ethics declaration, raise it at the start rather than after the sample arrives — it is a paperwork route, not a technical one, and it runs faster in parallel with the sample.