When your building intercom system project needs industrial control PCB assembly, the first question is usually about price. But the real question should be about clarity. We are Informic, and we coordinate turnkey PCBA for intercom teams across Eurasia. Our job is to turn a vague request into a precise, manufacturable plan. This article explains how we make purchasing clearer for you, step by step, without the guesswork.
Start with the finished board, not the component list
We often receive inquiries that list twenty part numbers but omit the operating environment. For a building intercom, that detail matters. A surface-mounted microcontroller that works fine in a lobby may fail in a damp stairwell or an unheated entryway. When you send us a request, we start by asking what the board must survive, not only what it must do.
Technical reference: For related engineering context, see IPC standards and industry resources.
Our first reply is a direct answer: we can coordinate your assembly, but we need three things from you. First, a schematic or a bill of materials. Second, any mechanical drawing of the enclosure. Third, a note on the expected production volume for the next twelve months. With those, we can give you a realistic quotation within a few working days.
Why the enclosure matters for your quote
The enclosure determines the board shape, connector heights, and thermal path. A slim intercom panel may require a board thickness of 1.6 mm or 1.0 mm, depending on the display and button travel. If we do not know the enclosure, we cannot confirm whether standard manufacturing tolerances will fit. This is not a delay tactic; it is a way to avoid a board that does not fit on day one.
We also ask about the cable entry. Are you using a top-entry or rear-entry terminal block? That choice changes the component placement and the soldering method. For example, a rear-entry block often requires a thicker copper pour to handle repeated plugging force. These are the small details that keep your production line moving.
How we structure a turnkey PCBA quotation
Our quotation is not a single number. It is a breakdown so you can see where your money goes. This transparency helps you compare offers from other suppliers without confusion. Here is the table we use internally and share with you.
| Cost element | What it covers | How we estimate it |
|---|---|---|
| Component sourcing | Purchasing all active and passive parts | Based on your BOM and current market prices |
| PCB fabrication | Bare board production and surface finish | Based on layer count, size, and quantity |
| Assembly labor | SMT and through-hole placement, soldering | Based on component count and board complexity |
| Testing | In-circuit test or functional test | Based on test points and test time |
| Logistics | Packing and shipping to your site | Based on weight, volume, and destination |
We do not hide the margin inside the component price. Instead, we show a separate coordination fee. This fee covers our engineering review, supplier communication, and quality checks. You know exactly what you pay for, and we stay accountable for the result.
The RFQ document that saves a week
To get a clear quotation faster, send a request for quotation (RFQ) with these five items. First, the target quantity per batch and per year. Second, the expected lead time from order to delivery. Third, the operating temperature range and humidity exposure. Fourth, any mandatory safety or flammability rating. Fifth, the preferred test method, such as a flying probe test or a functional test with your intercom firmware.
If you do not have all five, do not wait. Send what you have. We will ask targeted questions to fill the gaps. A partial RFQ is better than no RFQ, because it lets us start the component availability check while you finalize the schematic.
DFM: catching problems before solder paste
Design for manufacturability (DFM) is where we earn our coordination fee. We review your Gerber files and bill of materials against our assembly line capabilities. For industrial intercom boards, we look for specific issues. One common problem is a fine-pitch connector placed too close to a tall electrolytic capacitor. The pick-and-place nozzle cannot reach the connector without hitting the capacitor body. We flag this and suggest a small rotation or a different component footprint.
Another issue is thermal relief on ground planes. If the ground pad of a voltage regulator has no thermal spokes, the solder joint may be cold or incomplete. We add the relief pattern and re-run the DFM check. These changes are minor, but they prevent intermittent failures in the field.
BOM management for long production runs
Building intercom systems often have a production life of three to five years. A component that is available today may go end-of-life next year. We track your BOM against supplier notices and suggest alternatives before the shortage hits. For example, if a specific logic IC is being discontinued, we can propose a pin-compatible second source. We verify the electrical characteristics and the footprint, then update the BOM with your approval.
We also handle the "gray market" risk. When you source components yourself, you may receive parts from an unauthorized distributor. We buy only from franchised distributors or directly from manufacturers. This reduces the chance of counterfeit or re-marked parts in your intercom system.
Testing: what we actually verify
After assembly, we run tests based on the risk level of the board. For a basic intercom panel, we use an in-circuit test (ICT) to check for shorts, opens, and correct resistance values. For a more complex board with a display driver or a network interface, we run a functional test with your firmware. This test simulates the button presses and checks the audio output path.
We do not claim to test every possible failure mode. We do verify that the board operates within the electrical limits you specify. If you need a specific test, such as a 72-hour burn-in at elevated temperature, we can include that in the quotation. The cost increases with test time, so we discuss the trade-off with you before adding it.
When we recommend a design change
During the DFM review, we may suggest a design change that improves reliability without raising cost. For instance, we often recommend adding a small series resistor on the microphone input. This resistor protects the ADC from electrostatic discharge. It costs less than one cent and saves you from field returns. We present these suggestions as options, not as mandatory changes. You decide based on your own reliability targets.
We also check the solder mask clearance around test points. If the mask covers the test pad, the ICT probe cannot make contact. We ask you to expose a minimum of 0.5 mm of copper. This is a simple rule that prevents a whole batch from failing the test stage.
Communication during production
Once the order is placed, we send a production schedule with clear milestones. You will know when the PCB fabrication starts, when the components arrive, and when the assembly begins. If a component is delayed, we tell you immediately and propose a substitution or a schedule adjustment. We do not wait for the issue to become a crisis.
For urgent orders, we can split the production into smaller lots. This allows you to receive a first batch for installation while the rest is still being assembled. The unit price for the small lot is slightly higher, but you gain time. We present this option when the schedule is tight.
Payment and delivery terms that fit your workflow
For a first order, we typically require a 30% deposit and 70% before shipment. After two successful orders, we can move to net 30 terms. This reduces your administrative burden. Delivery is by freight forwarder, and we provide the packing list and customs documents for export outside China. We have experience shipping to multiple Eurasian countries, so we know which documents are needed for customs clearance.
What we do not do
We do not claim to be the cheapest supplier. If you need the lowest possible price and can accept longer lead times and less support, another vendor may suit you better. We focus on coordination quality and communication. We also do not assemble boards with unknown or counterfeit components. If you insist on using parts from an unverified source, we will decline that part of the order. This protects your product and our reputation.
We do not offer a fixed price for an undefined scope. If you change the BOM or the board size after the quote, the price changes. We document these changes in writing so there is no dispute later.
How to get a quote from us
To start, send your schematic and BOM to our contact page. We will review the files and reply with a list of clarifying questions. Once we have the answers, we issue a formal quotation with the table shown above. The quotation is valid for 30 days, which covers your internal approval cycle.
We also provide a sample board for your own testing before you commit to a full production run. The sample cost is deducted from the first production order. This is a practical way to verify our work without a large upfront investment.
FAQ
Do you provide the bare PCB as a separate item?
Yes. We can supply the bare board alone if you have your own assembly line. You will receive the pcbManufacturing files and the finished boards with the specified surface finish. The quotation will show the bare board cost separately from the assembly cost.
Can you handle a BOM with parts we already purchased?
We can, but we will inspect each part for authenticity and condition before assembly. If any part shows signs of rework or damage, we will set it aside and inform you. The inspection fee is modest and is included in the coordination cost. This service is useful when you have surplus inventory from a previous project.
What is the minimum order quantity for a turnkey pcba service?
Our minimum is 100 boards per batch. For lower volumes, the setup cost per board becomes high. If you need a prototype run of 10 to 20 boards, we can do that as a separate engineering service. The prototype price is higher, but it helps you validate the design before mass production. We use the same components and process for prototypes as for production runs.
