Introduction: Custom terminal work turns a diode purchase into a joint engineering project, and the supplier must handle lead forming, termination, and testing, not just diode supply.
A production team often begins with a standard axial leaded diode and hand-wires it. As build volume rises and the harness gets longer, every soldered joint on a 12KV line can concentrate field at a sharp solder point or a cold connection. A quick connect terminal formed onto the diode lead lets the harness slide on. Reaching that point requires a manufacturer that can form leads, control terminal geometry, and test the finished part. Before requesting a quote, gather the details below and judge whether a supplier can support the customization.
On a standard low frequency high voltage diode, the lead is a connection point. An operator solders it into a board or clamps it under a screw, and the supplier's responsibility ends at the epoxy body. With quick connect terminals, the lead becomes a mechanical part with its own tolerances. Bend radius, tab width, angle relative to the body axis, and flatness of the forming must repeat from unit to unit because the mating connector on the harness side is unforgiving. That skill differs from diode assembly, and weak quotes often fail there. The evaluation also changes. For a stock diode, compare voltage, current, surge rating, and price. For a custom terminal diode, compare the supplier's ability to hold a forming process, keep plating intact through bending, and confirm that the finished joint survives the pull and torque it will see on the line. High voltage parts raise the stakes because the terminal is metal at 12KV, and its shape and spacing affect how the field distributes around the component. A high voltage diode manufacturer that only ships straight leads may accept the order and then discover the forming tooling is unavailable. A high voltage diode supplier that already forms leads can quote the same job with a realistic process behind it. The useful screening question is not "Can you make a 12KV 350mA diode?" but "Can you make it with this terminal, in this orientation, and test it before shipment?" The first question has many answers. The second has fewer, and it decides whether the assembly line gets faster or gains a new source of rework. Ask it early to avoid samples that never meet the drawing.
A custom terminal RFQ is closer to a manufacturing instruction than a price request. The factory has to decide whether the lead can be formed without cracking the plating, whether the terminal can be attached without thermally stressing the die, and how the finished part will be inspected. Those decisions depend on the drawing, the mating connector, and the environment where the diode will operate.
Start with the lead. The manufacturer needs the lead diameter, the free length before forming, the finished length after forming, the bend radius, and the tolerance band on the terminal position. Then define the terminal: blade, receptacle, ring, eyelet, or bent tab, plus its width, thickness, and direction relative to the body. Send a drawing or sample of the mating harness connector, because the diode side is usually designed backward from what already exists on the assembly floor. Body length and diameter should come from the published datasheet drawing, since those dimensions are fixed by the 12KV die package and cannot be traded away for terminal convenience.
The second half of the RFQ is about where the part lives and how it is handled. Creepage and clearance along the surface, and through the air or medium between conductors, set how much space the formed terminal needs from the body and from nearby metal. Texas Instruments' creepage and clearance guidance is a useful reference when the terminal layout is still flexible. IEEE 1205 is worth reading for how high field stress is controlled around electrodes and terminations. If the diode sits in insulating oil or an insulating gas, the medium fills the gap and the spacing constraint relaxes, but the potting compound still has to cover the joint consistently. In open air, sharp formed edges and tight terminal spacing become the first places to discharge. Assembly conditions matter too: whether potting happens before or after the connector is mated, how much torque the terminal sees, and whether the harness pulls on the joint during routing.
CL01-12 is a practical starting point for terminal customization requests. It is a low frequency high voltage diode rated 12KV and 350mA with a 30A surge capability, built with an axial leaded connection, and quick connect terminals can be installed on it. The body uses high thermal conductivity epoxy molding, and a special high temperature resistant chip protective glue sits inside. That construction helps protect the die through the heat that lead forming and terminal attachment can introduce. HVDIODE supports OEM and ODM customization for terminal type, lead form, and related electrical parameters, so the conversation is not limited to one stock configuration. Testing is where a customization project becomes credible. For terminal work, the formed joint should be checked at voltage and after thermal cycling, not only visually. HVDIODE reviews the lead drawing, terminal type, operating medium, target quantity, and the electrical parameters the part must hold, along with the test conditions the finished assembly will face. The factory checks whether the lead form and termination are manufacturable. A dedicated customer service manager then confirms MOQ, price, lead time, terminal dimensions, and any insulation or potting questions one to one. Terminal dimensions and whether a particular terminal is standard or fully custom are confirmed in that exchange rather than assumed from a catalog page.
Choosing a manufacturer for custom terminal diodes comes down to whether the supplier can own the interface, not just the die. Lead forming, terminal geometry, creepage and clearance, potting method, and post-assembly testing all sit between your design and a faster assembly line. Bring a lead drawing, the mating connector details, the operating medium, and target quantities to the first conversation. Ask directly how the factory will form and verify the joint. Send those details to the supplier, request the CL01-12 datasheet, and ask for a sample with your terminal configuration so the specification, MOQ, and lead time can be confirmed.
A：Prepare the axial lead drawing with diameter, free length, finished length, and bend radius, plus the terminal type, width, thickness, and orientation relative to the body. Add the mating harness connector drawing or sample, the operating medium such as insulating oil, insulating gas, or open air, the potting method, and the torque or pull the joint will see. Include the electrical parameters the diode must hold, your target quantity, and the assembly conditions on your line. With those items in hand, the factory can review manufacturability and prepare a quote more efficiently.
A：Creepage is the path along a surface between conductors, and clearance is the shortest path through the air or medium. On a 12KV part, a formed terminal changes both because metal now extends away from the body and its edges become points where the field concentrates. If the diode operates in insulating oil or an insulating gas, the medium fills the gap and spacing becomes more forgiving, but the potting compound must cover the joint consistently. In open air, the terminal layout usually needs more distance and smoother edges to avoid discharge. Terminal geometry and spacing belong in the RFQ, not in a later change order.
A：Yes. Send the lead diameter, free and finished lengths, bend radius, terminal type, and orientation. The engineering team will review whether the form is manufacturable on the CL01-12 body before commercial discussion starts. The review considers whether bending can damage the plating or stress the epoxy molding, and whether the terminal position can be held within tolerance. If the drawing needs adjustment for manufacturability, that feedback comes before samples are made. Terminal dimensions and the standard-versus-custom status of a specific terminal are confirmed with the customer service manager during that exchange.
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Texas Instruments PCB Creepage and Clearance Distance Design Guide
