ESD Tray with Grids

Six parts, one tray, no tools

The tray is assembled from a moulded base, a base pad, two lengths of fluted divider and a cover. Every part is replaceable on its own, which is what keeps a grid reconfiguration a five-minute job instead of a purchase order.

• Moulded conductive base. The shell that carries everything else: conductive polypropylene, moulded with corner posts that locate the cover and keep stacked trays from sliding.
• Anti-static EVA base pad. A 457 x 289 x 5 mm pad sits flat in the base. It cushions lead ends, stops small parts from working their way under a divider, and gives the tray a soft floor.
• Three long dividers. Fluted anti-static board cut to 457 mm, running the full internal length. Three of them set four rows across the 289 mm width.
• Four short dividers. The same board cut to 289 mm, crossing the long dividers. Four of them set five columns along the 457 mm length.
• The grid they make. Four rows by five columns gives 20 cells at about 91 x 72 mm. That pitch suits most through-hole components, connectors and small sub-assemblies.
• Reconfigure without reordering. Lift a divider out and the cells either side become one. Move it and the pitch changes. The tray follows the BOM instead of the BOM waiting for a tray.
• Cover, seated not screwed. A 457 x 289 x 5 mm fluted board lid drops onto the corner posts. Nothing to lose, nothing to thread, and the tray is closed in one movement.
• Stack and nest. Closed trays stack on their posts and nest when empty. Storage grows upward instead of across the floor, which is usually the cheapest capacity a factory can add.

Three grid pitches cover most of a THT line

Cell size decides what the tray is for. Small cells separate chip components; wide cells take reels, tubes and sub-assemblies. The tray shell is often the same - the divider set is what changes.

• Fine grid, up to 80 cells. Cells of 36 x 18 mm or 40 x 24 mm. For chip components, small ICs and anything where two part numbers in one pocket is the real risk. Cells are shallow, so parts do not migrate between pockets.
• Standard grid, 20 cells. Cells of about 91 x 72 mm in a 457 x 289 x 45 mm tray. The pitch that suits through-hole resistors, capacitors, connectors and odd-form parts, and the one shown in the assembly drawing supplied with the enquiry.
• Wide cells, 10 cells. Cells of 168 x 64 mm. For tape reels, stick tubes, larger connectors and pre-assembled sub-boards that need to travel without touching each other.

Open points, shown as found

Six parameters are not consistent across the supplied items. They are printed here side by side rather than averaged, resolved in silence, or dropped. Each one is a question to settle in the quotation, not after the tooling is cut.

What one tray holds, cell by cell

Capacity is set by the cell pitch, not by the tray footprint. At one part per cell the count below is the count you can kit without re-counting. Packing two parts into a cell is possible and is exactly what the grid exists to prevent.

Every parameter is adjustable

Send the component dimensions, the process temperature and the count you need per board. The tray is sized to the parts, not the parts to the tray.

• Custom dimensions. Any external footprint and any internal depth. New tooling typically takes 15 to 25 days, so the geometry is agreed before the mould is cut.
• Grid count and layout. From two wide cells to 80 fine ones. Because the dividers are separate parts, one tray covers several BOMs and the layout changes without a new purchase.
• Colour coding. Black is standard; red, yellow and green are held for the range. Colour is compounded into the material rather than painted, so it does not wear off at the handling points.
• Temperature grade. Standard grade for a normal assembly floor, or a 120 °C and 150 °C grade for trays that live near a reflow oven, a wave solder pot or a selective solder cell.
• Surface marking. Silk-screen part numbers, cell numbering, handling instructions or a customer mark. Anti-static labels carry the variable data that printing cannot.
• Covers, pads and spare dividers. Covers for storage and transit, replacement EVA pads, and dividers ordered separately so a grid can be rebuilt without buying another tray.

Putting the trays into an ESD control plan

A tray only does its job inside a grounded programme. These are the six steps that decide whether the trays you buy change anything on the floor.

• Confirm the ground path first. Check the workstation earth points before the trays arrive. A conductive tray that never touches a grounded surface is a plastic box with an unusual colour.
• Set the grid to the BOM. Insert the dividers for the part mix on the line and label each cell with its part number or lot code. Agree the layout with the operators, not for them.
• Meter on receipt. Measure surface resistance when the trays land and record the reading against the delivery. That first number is the baseline every later audit is compared with.
• Train the two rules that matter. Parts go into the tray before they move, and trays are never dragged across a bench. Those two habits cover most of the ways a tray stops working.
• Set an audit interval and keep it. Re-meter on a fixed cycle and retire trays that have drifted out of range. The interval matters less than the record - an audit nobody writes down is not an audit.
• Reconfigure between runs. When the BOM changes, change the dividers rather than the trays. This is the step that makes a grid tray cheaper than a rack of single-purpose bins.

Support around the deployment

A tray order is a small purchase with a long tail. These are the four points where we usually end up doing the useful work.