Five questions a rack supplier should ask before quoting

A quote that arrives immediately, with no questions attached, is a guess with a price on it. There are five things that decide whether a rack will work, and a supplier who has not asked for them does not know whether what they are quoting fits.

1. What are the board dimensions, and are they finished dimensions

The outline decides the slot. The distinction that matters is between the drawing and the finished article, because a depanelled board can be very slightly larger at the tab positions than the drawing says.

If the answer is a drawing number, the follow-up should be whether anyone has measured a real one. On a first order for a new board, that difference is the most common cause of a rack that nearly fits.

2. How tall is the tallest component

This decides slot pitch, and it is the question most often skipped, because it is the only one of the five that is about the board as a three dimensional object rather than an outline.

A supplier who asks for length and width and stops has quoted a rack that will hold your boards if they are bare and may not if they are populated.

3. Does it have to interface with a machine

Everything changes on this answer. A storage rack and a magazine that feeds a loader are not the same product even at identical dimensions, because the magazine has to satisfy the machine's envelope, pitch and rail tolerances.

If the answer is yes, the machine make and model belongs in the first message. If the answer is not yet but possibly later, that is worth saying too, because it changes what is sensible to buy now.

4. What is the thermal and ESD environment

Two questions that sound like housekeeping and are not.

Thermal: does the rack enter an oven, or sit near a hot process. Ambient near a curing chamber is not room temperature, and a standard rack in that position is being cycled whether or not anyone calls it a high temperature application.

ESD: are the boards bare or populated, and what does your standard require. Bare boards and populated boards point at different material choices, and the difference is not a preference.

5. How many boards are actually queued at once

This decides slot count, and the useful answer is not batch size or monthly volume. It is how many boards sit between operations at any one moment.

A supplier who quotes against monthly volume will quote too much rack. One who quotes against batch size will usually quote too little.

What to send in the first message

Finished board dimensions, tallest component height, whether a machine is involved and which one, the thermal and ESD requirement, and the number of boards genuinely queued at once.

Those five make a real quote possible on the first pass instead of the third. Send them through request a quote, or if you would rather work it out first, how to choose an ESD PCB magazine rack walks the whole decision and how to size a rack to your boards covers the measurements.