Custom display RFQ: what to send so engineering can help

The common mistake: sending only size and quantity

Many RFQs say “need 4.3 inch display, 1000 pcs”. That is a start, but it is not enough to recommend the right module.

A useful RFQ includes the device use case, interface, touch requirement, brightness, mechanical limits, quantity stage, and schedule.

Use a simple first message structure: application, display size, resolution target, interface, touch need, brightness environment, mechanical limits, sample quantity, mass quantity, and timing. Even if some fields are unknown, write “flexible” or “not decided yet”.

Engineers sometimes hide uncertainty because they want the RFQ to look professional. It is better to show uncertainty clearly. A supplier can often recommend a standard module if they know which points are flexible.

A good RFQ is not a perfect technical document. A useful rule is that a useful RFQ is simply honest and complete enough for the first engineering decision. If something is unknown, say it is unknown. If something is flexible, say it is flexible.

For quantity, separate sample, pilot, and mass production. A sample request for five pieces and an annual demand of 20,000 pieces lead to different advice than a one-time 100-piece project. MOQ and customization decisions depend on this.

Then list the fixed points. Maybe the housing opening is already tooled. Maybe the PCB already has RGB. Maybe the software supports only one controller. These are hard constraints. After that, list preferences, such as preferred resolution or brightness target.

Finally, add the question you want answered. “Please recommend a standard module if possible.” “Please review whether this FPC direction is feasible.” “Please quote PCAP with 2.0 mm cover glass.” Clear questions guide the supplier response. Without them, you may receive a price but not the engineering help you need.

Start with the application

Tell us what the display goes into: medical device, EV charger, handheld scanner, POS terminal, elevator panel, outdoor controller, or something else.

The application changes the recommendation. The same 7 inch size can need very different brightness, touch, glass, and testing.

Add the user environment in one sentence: indoor counter, outdoor wall, vehicle cabin, hospital cart, factory machine, handheld warehouse use, or public kiosk. This tells us more than only the industry name.

If there is a similar existing product, send a photo or link. You do not need to share confidential drawings to explain the use case. A reference photo helps align brightness, glass, touch, and mechanical expectations quickly.

Start with the application. “Medical handheld reader” is more useful than “3.5 inch LCD”. “Outdoor EV charger payment screen” is more useful than “7 inch touch display”. The application tells us about brightness, glass, touch, environment, certification, and supply expectations.

For timing, be direct. If samples are needed next week, say so. If mass production is six months away, say so. A technically perfect custom part may be wrong if the schedule needs a standard module now.

Attach rough files early. A partial drawing, product photo, front opening sketch, or board screenshot can prevent misunderstanding. Project engineers sometimes wait until drawings are perfect, but the best supplier feedback often comes while the design can still move.

List what is fixed and what is flexible

If the size is fixed but interface is flexible, say that. If the interface is fixed but resolution can change, say that too.

RFQs become harder when every point is presented as fixed. In reality, one flexible parameter may allow a standard module and save cost.

Use three labels in your RFQ: must have, preferred, flexible. For example: “Must have 5 inch class size, preferred 800x480, flexible interface if module is available quickly.” This is much easier to work with than a long rigid list.

Also mention what cannot change because of tooling, PCB, software, certification, or customer approval. Those constraints matter more than preferences.

Then list fixed points and flexible points. This is one of the most helpful habits. If size is fixed but resolution is flexible, write that. If the PCB already requires MIPI, write that. If the interface can change to fit an available module, write that too.

End the RFQ by asking for comments, not only price. Ask whether a standard module fits, what must be customized, what risks they see, what documents can be supplied, and what sample path they recommend. That invites an engineering answer instead of only a sales quotation.

End with the decision you need: standard module recommendation, custom FPC review, touch and glass proposal, sample availability, MOQ, lead time, or document support. A clear question helps the supplier answer with engineering value instead of only sending a catalog link.

Add mechanical and touch details

Useful details include front opening, cover glass size, FPC exit direction, connector side, total thickness limit, touch type, glove use, water exposure, and whether logo printing is required.

A drawing is helpful, but a rough screenshot or photo of the product concept can also be enough for early advice.

If you have a PCB already, send connector location and available height. If you have a housing already, send front opening and section view. If you have neither, send the desired product size and where the display should sit.

For touch, say how the user touches it: bare finger, wet finger, thin glove, thick glove, stylus, or occasional cleaning. This often changes cover glass and controller recommendations.

Attach rough drawings even when they are not final. A front opening sketch, PCB connector area, product photo, or cross-section can save several rounds of email. The drawing does not need to be polished; it needs to show constraints.

When writing an RFQ, write it like an engineer asking another engineer for help. Do not hide uncertainty. Do not make every point sound fixed. Explain the product, the constraints, and what is still flexible.

For RFQ review, ask a project engineer to read the request as if they are the supplier seeing the project for the first time. Can they understand the device, the fixed constraints, the flexible points, the quantity stage, and the timing? If not, the RFQ will create email loops instead of answers.

Clarify quantity and timing

Separate sample quantity from mass production quantity. Also mention target sample date and expected production start.

This helps avoid quoting a module that is fine technically but wrong for availability, MOQ, or lead time.

Be honest about stage: concept, prototype, pilot, approved design, or repeat order. Sample strategy is different for each stage. A concept may need available standard modules; an approved design may justify customization.

If the project has a fixed launch date, say it early. Then availability and lead time can be treated as design constraints, not as an unpleasant surprise after technical selection.

For touch, describe the user. Bare finger, glove, wet finger, stylus, cleaning, public use, and thick cover glass all change the recommendation. If you only write “with touch,” the supplier has to guess.

The first paragraph should say what the device is. A display for an outdoor charger, medical reader, handheld scanner, elevator panel, or POS terminal gives immediate context. That context affects brightness, touch, glass, interface, quality, documents, and supply.

Then remove false precision. If you prefer 800x480 but can accept another resolution, say preferred, not required. If you want 1000 nits but do not know the real outdoor condition, say target, not fixed. Good RFQs show flexibility honestly. That helps us recommend available modules instead of chasing a custom part too early.