Reading a PCBA Quotation Line by Line

Two figures for the same board can differ by a factor of two, and the difference is rarely a matter of margin. Assembly is a process with several distinct costs, and a quotation that presents them as one number conceals which of them applies, which of them is optional and which of them would change if the order were different.

Reading a quotation line by line is therefore a practical skill. It takes a few minutes and it answers the questions that otherwise surface after the order is confirmed: what is included, what is excluded, and what the figure assumes about the material and the schedule.

The Placement Charge and the Placement Count

The largest line is usually the placement charge, expressed as a rate per position multiplied by a count. The count is derived from the coordinate file, and it is worth checking, because the way positions are classified affects the total.

A small passive, a fine-pitch device and an area-array package are not equally difficult to place, and a quotation may reflect that in different rates per class. That is reasonable, provided the classification is stated. What is not reasonable is a single count that quietly treats every position as difficult, or one that omits positions which require rework.

The rate itself depends on the volume. The same position costs more on a small order than on a large one, because the preparation behind it is the same. Asking what the rate would be at a higher quantity is the quickest way to see how much of the price is preparation and how much is work.

The Engineering Fee and What It Covers

The second line covers the work that happens before production: the review of the data, the creation of the placement programme, the stencil, the first article verification and the test definition if one is required.

These are one-off costs, so their weight falls entirely on a small order, and they are the main reason a small batch is proportionally expensive. They are also the part of the quotation that a customer can influence. Complete data, a stable revision and a settled material list reduce the engineering work; a second order for the same product should eliminate most of it, and a quotation that repeats the same stencil charge for a product already built is worth a question.

Where the fee is not itemised, it is worth asking what it includes. A quotation that bundles the stencil, the programme, the first article and the test definition into the placement rate cannot be compared with one that lists them separately, and the two are not describing the same service.

Material Cost and the Surplus Behind It

Where the parts are bought on the customer’s behalf, the material appears as its own line, and the questions that matter concern the surplus and the allowance.

A device with a minimum order quantity is bought in the quantity available rather than the quantity required, and the treatment of the remainder affects the total. Some quotations include the whole purchase; others include only what the order consumes and either carry the remainder as stock or return it. Neither approach is wrong, but the customer should know which one applies and whether the surplus is stored for a future order.

The allowance for attrition is the other element. Assembly consumes material during setup and adjustment, so the requirement is greater than the count multiplied by the number of boards. Where the allowance is stated as a percentage it can be checked; where it is invisible, the difference appears as a change note later.

Substitution is the third. Where a part is unavailable, the quotation is only accurate if the alternative is inside the agreed range, which is why the replacement rules belong with the order rather than to the conversation that follows the order.

Testing, Coating and Other Operations

Each additional process appears as its own line if it is charged separately, and disappears into a general figure if it is not. Programming, functional testing, a coating, the separation of the panels and the packing are the common ones.

The useful check is that the sequence is priced rather than assumed. A test that must happen before a coating, or a programming step that requires a fixture, changes the work, and a quotation that lists only the operations without their order can conceal an assumption about it.

Where a test fixture has to be made, that is a one-off cost like the stencil, and it should be treated the same way: a legitimate charge on a first order and a questionable one on a repeat.

The Expedite, the Date and the Assumptions

An urgent schedule is a separate line in most quotations, and it should be. Compressing the work means displacing something else or paying for additional time, and a supplier who does not charge for it is either very lightly loaded or planning to recover the cost elsewhere.

The assumptions behind the date are worth reading as carefully as the price. A quotation that is valid only if the material arrives complete, if the data does not change and if the first article passes is a different offer from one that includes a defined amount of engineering support and a procedure for what happens if something moves.

Two further items belong in the same review. The packing method and the delivery format, since a requirement for individual antistatic packing affects the work; and the basis on which the quantity was quoted, since a figure quoted for a batch of fifty and produced for a batch of forty is not the same order.

Quantity Breaks and What They Reveal

Asking for a price at several quantities costs nothing and answers a useful question: how much of the total is preparation and how much is work. Where the figure barely moves between fifty units and a hundred, the preparation dominates and the second order will be far cheaper than the first. Where it moves in proportion to the quantity, the price is dominated by placement and material.

That distinction also shows where a change would help. If preparation dominates, reducing the number of variants, settling the revision earlier or allowing more flexible scheduling affects the price more than a discount would. If placement dominates, the only lever is the quantity itself.

A quotation that cannot be produced at two quantities is worth a second look, since the information required to derive it exists in every case. The operations behind the figures are the ones described elsewhere: assembly work, verification and the controls that keep a batch repeatable.

Comparing Offers That Include the Same Things

The method that works is to make the two documents describe the same scope: the same revision, the same material basis, the same list of operations, the same inspections, the same packing and the same deadline. Once that is done, the remaining difference is a difference of price.

Before that point, a comparison measures the two suppliers’ assumptions rather than their prices, and the lower figure is often the one with the larger number of exclusions. The operations being quoted are SMT assembly, through-hole assembly for inserted parts and PCBA testing where verification is required, all governed by the controls described under quality management.

FAQ

Why is one stencil charge repeated on a repeat order? It should not be, if the stencil still exists and is suitable. It is worth asking whether a new one is needed and why.

Should the material allowance be visible? Yes. An allowance stated as a percentage can be checked; one that is not stated appears later as a change.

What is the fastest way to compare two quotations? Ask both to state what is included, what is excluded and what the date assumes, then compare the scope before the price.