Stamp Hole PCB Cost: Panel Design, Layers and Volume
What a Stamp Hole Actually Is
A stamp hole edge is a row of small drilled holes left along the outline of a panel so that a sub board can be snapped off by hand or with light tooling. The holes, usually 0.5 to 1.0 mm, are linked by narrow bridges of laminate, and because the outline runs through the middle of each hole the finished board carries a row of half holes. That construction is why the price behaves differently from a plain routed outline: the holes have to be drilled, the outline has to be routed through their centres, and the edge finish has to survive the snap. When a quotation is higher than an equivalent rectangular board, one of those three operations is usually the reason.
Panel Utilisation Sets the Base Cost
Every board is built inside a working panel, and the percentage of that panel occupied by finished boards is the single largest lever on price. Stamp holes force a row of holes along the board edge instead of a clean mechanical route, and the hole row needs space around it for the drill to enter and for the tab to break cleanly. A design that packs boards tightly with routed outlines cannot always be packed as tightly with breakaway edges, so the panel may hold fewer pieces. Losing one board position from a four-up panel is a twenty five percent increase in the material and processing content of each unit, which is why the panel drawing matters as much as the electrical design.
Breakaway Design and Tab Width
The width and number of the connecting tabs decide how much of the hole row is drilled, how many breaks the assembler has to handle, and whether the edge needs support. Narrow tabs break easily and leave a clean edge but can let the sub board move during assembly; wide tabs need more force and can delaminate the laminate near the hole. Managing that trade costs money in two places. The drill program grows with the number of holes, and the routing step grows with the number of tabs that must stop short. A design that specifies the tab width, the hole pitch and the tolerance in the fabrication notes avoids a back and forth that would otherwise add days rather than dollars.
Layer Count and Hole Format
Layer count multiplies the drill and plating content of the panel. A two layer stamp hole board is a simple drill and route job. Move to four or six layers and every stamp hole adds plating barrels that must be uniform, and the risk of breakout at the edge rises because the hole wall is now exposed through several layers. That is why fabricators often apply a heavier copper ring or a wider edge keep out on multilayer breakaway edges. The cost effect is modest at six layers and grows sharply from eight upwards, because the layer alignment tolerance now has to hold a half hole at the panel edge as well as the internal features.
Quantity, Tooling and Setup
Setup is a fixed cost, so the unit price falls steeply with volume. A stamp hole design needs a drill program, a routing program that runs along the hole centres, and possibly a laser cut or a scoring step depending on the material. Those costs are paid once. The variable cost is drilling time, routing time, copper and laminate, and it scales with area and layers rather than with the number of pieces. That is why ordering ten pieces can cost nearly as much per unit as ordering fifty, and why prototype buyers should ask for the setup and per unit split rather than a single figure.
What Else Moves the Quote
Edge plating or castellation. If the half holes must be plated, as in a module that solders directly to a carrier board, the holes need plating before routing and the price steps up substantially. Surface finish. ENIG and hard gold cost more than HASL, and a plated castellation edge is usually finished to a tighter specification. Tolerance. A snap that must release within a tight dimensional window needs a controlled hole pitch and a stress relieved laminate. Material. High frequency and polyimide laminates cost more and are more brittle at the break line. Inspection. A visual check for micro cracks along the snapped edge adds labour but prevents field failures.
How to Reduce the Cost
The cheapest change is usually at the layout stage. Give the breakaway edge its own clean band, keep traces and vias at least 0.5 mm inside the finished outline, and keep that band free of components so the snap cannot stress a joint. Specify the smallest hole that still breaks cleanly, standardise the tab width across the range, and place the stamp holes on a regular pitch. Then discuss panelisation with the fabricator before release, because a panel layout that the shop can build without special tooling removes cost from the quote without changing the circuit at all.
Stamp holes sit at the junction of mechanical and electrical design, so the choices should be reviewed alongside the rest of the stack. Compare the process steps in PCB manufacturing, apply the spacing rules from PCB design and layout, and read the design and manufacturing considerations before release. If the boards are assembled in house, an prototype PCB assembly run will show how the panel behaves on a real line.
FAQ
Why does a stamp hole board cost more than a routed board? Because the outline runs through the holes, adding drilling and a specialised route, and because the breakaway band can reduce panel utilisation.
Is a stamp hole cheaper than V scoring? For small or dense boards, often yes, because scoring cannot run across components. For large rectangular boards with no parts near the edge, scoring is usually cheaper.
Can the half holes be plated? Yes, and they must be if the edge will be soldered to another board, but plating before routing adds cost and process steps.
How do I get an accurate quote? Send the panel drawing with hole pitch, tab width and remaining panel size, and ask for setup and per unit cost separately.
Conclusion
Stamp hole cost comes down to three numbers: how much of the panel the boards fill, how much drilling and routing the edge requires, and how many pieces share the setup. Reduce the breakaway band to what the snap needs, plate the half holes only when the application demands it, and confirm the panel layout with the fabricator before ordering. In 2026 that approach keeps the price of a breakaway board close to that of a plain rectangular one.
