PCB vs PCBA vs SMT stencil: what to order and when

People use PCB, PCBA and stencil as if they were the same purchase. They are three different objects, and ordering the wrong one wastes a revision. A PCB is the bare board. A stencil is the metal sheet that prints solder paste onto that board. A PCBA is the board after the parts have been placed and soldered. You can buy any one of them. You should not assume the others are included.

Sonani Electronics does not run a fabrication line. We source and deliver the parts, and bare boards, stencils and assembly are made through our manufacturing partners. The quotation is in INR. You get a single GST invoice, and there are no hidden charges after you approve it.

The bare PCB

Order a bare PCB when you will solder the board yourself, when you only want to check the mechanical fit in an enclosure, or when the parts are not final and you do not want assembled boards you cannot rework. You send a Gerber and drill set, plus the stack you want: layers, thickness, copper, surface finish and solder mask. Those choices are explained in choosing PCB specs.

A bare-board order does not include components, solder paste or assembly. If your file has a paste layer, that is information about the pads. It does not mean a stencil will arrive in the same packet unless the quote lists a stencil.

Start this order from the PCB fabrication page or by uploading the Gerber on the instant quote page. Each zip you send is stored as a revision. If you later change the outline or a footprint, that is a new file and may be a new price. The rules are in the PCB fabrication and stencil terms.

The SMT stencil

A stencil is a thin metal sheet with openings where solder paste should sit. You print paste through it, then place the parts. Order a stencil when:

• You already have bare boards, or they are on the way, and you will paste them yourself.
• Your own line has a printer, and you need a framed stencil that fits it.
• You are hand-pasting a small batch and a frameless stencil is enough to hold against the board.

Say framed or frameless. A frame suits a printer. A frameless sheet is what many people tape to the bench. Fine-pitch parts usually want a thinner foil than large power pads. If the board has both, say so, because one thickness is a compromise.

The stencil comes from the paste layer. If that layer is missing or from another footprint, the paste will miss the pads. Export it with the copper. Packing the Gerber is covered in preparing Gerber, BOM and pick-and-place files. A stencil order does not include the board, the parts or the paste. For assembly, the manufacturing partner uses a stencil. Buy one yourself only if you will print the paste.

The assembled PCBA

PCBA means the parts are on the board and soldered. Order this when you want a board you can power, test or ship, and you do not want to run the paste-and-place step yourself. You still provide the design. A normal pack is:

• Gerber and drill, including paste
• BOM with manufacturer part numbers, designators, quantities and DNP marks
• Pick-and-place file with X, Y, rotation and side
• How many boards, and whether any parts are consigned by you

We source the parts unless a line says you will supply that part. India-sourced and imported lines can share a quote. Imported parts typically reach Surat in about 12-15 working days, India-sourced parts about 2-4 working days, depending on stock. The quote shows which is which. BOM best practices is how to write the lines so that split is obvious.

Assembly follows the files you approved. A designator on the BOM but missing from the centroid will not be placed. A DNP part left in the centroid can be placed by mistake. Write hand-inserted parts in the message: "J1 is inserted after reflow."

Which one to buy first

A first product is often a bare PCB, built by hand or with a stencil, then a PCBA once the BOM has survived bring-up. A copy of a working board can go straight to PCBA. Do not assemble against "or equivalent" on the expensive ICs. Approved alternates go in their own column after package, pinout and voltage are checked. See finding alternatives.

What is never included unless the quote says so

These are separate lines. If you need one, say so before the quote is accepted.

• A stencil, when you ordered only bare PCBs
• Components, when you ordered only bare PCBs or only a stencil
• Assembly labour, when you ordered only boards and parts as loose materials
• Testing beyond a visual check of the assembly, unless you supply a procedure
• Conformal coating, potting, programming, or fitting the board into an enclosure
• A panel, tooling, or a change of surface finish after the files were approved

Special board features, such as controlled impedance, castellated edges or via-in-pad, are also outside a plain stackup. The terms list them. Mention them in the first message so they are on the quote and not discovered after payment.

How the invoice works

You are buying from Sonani Electronics in India. Shipping, customs, duty and clearance for parts we import sit inside the quotation. GST is shown on it. You receive a single GST invoice, and there are no hidden charges. If a file or a part number is missing, we say so instead of guessing a price.

Search parts or upload a BOM before the board is finished. Contact us if you are unsure whether this build is a bare board or a PCBA. A photo helps. The Gerber is still required before anyone can fabricate.

Common questions

If I order PCBA, do I also buy a stencil?

No. Our manufacturing partners use a stencil as part of assembly. Order one yourself only when you will print the paste. If you want that stencil shipped to you afterwards, it is a separate line.

Can I buy bare PCBs now and assembly later?

Yes, if the Gerber revision stays fixed. Send the BOM and centroid from that same revision. A new layout may not match the old boards.

We solder by hand. Do we need a stencil?

Not for an iron and wire. You still want silkscreen polarity and a real part number on the BOM. A stencil helps when you would rather print paste for many small parts or a fine-pitch IC.

Is PCBA the same as turnkey?

Read the quote lines. PCBA here means the board is assembled with the parts listed. Consigned parts are not sourced by us. Programming, calibration and fitting the board into a box are included only when a line says so.