Component Preform and Lead Forming for Axial and Radial
What we make up
Axial components —terminals that come out of both ends of the body— and radials —terminals that depart from the same side and in parallel—. Historically, the following have passed through this line:
- Resistors and capacitors
- Diodes, transistors, and triacs
- Varistors and fuses
- Transformers and connectors
And the operations that usually go with shaping:
- Custom-formed to fit your PCB, including multi-step geometries when the component must lie flat or be raised.
- Terminal cut to length, which we also provide separately.
- Repackaging of the formed component, ready for the insertion station.
The rule that decides if a preform is well made
Conforming is not about bending the pin where it suits you. The standard IPC J-STD-001 It specifies that the fold must begin at a minimum distance from the body of the component: a terminal diameter, and never less than 0.8 mm.
The reason isn't aesthetic. Inside the component, the terminal is soldered or sealed to the body. Bending it too close transmits stress to that joint and can break the seal. It's damage that can't be seen.It passes the visual inspection, passes the electrical test, and appears months later in the field as an intermittent failure.
The other two limits that are monitored in each run:
- The radius of the bend It must not be smaller than the diameter of the terminal. A tight bend cracks the coating and leaves the copper exposed to corrosion.
- The component is not held by the body. For bending. The terminal is held between the body and the bend, so that the stress never reaches the encapsulation.
When the preform is made by the assembly line itself using improvised tools, these three things are precisely what get overlooked. The cost doesn't appear in that run; it appears in the warranty return.
When does it make sense to outsource it?
- The component does not come in the geometry that your PCB requires. And configuring it online forces you to stop or improvise a tool.
- You have a lot of part numbers with different geometries and a small quantity of each.
- The component is sensitive —made of glass, airtight, with a fine terminal— and the margin of error is small.
- You need documented acceptance criteria by batch, not the operator's word.
- You got one urgency and your capacity is already compromised.
We work the same way High mix with low volume What sustained runs: the 6.3 million pieces of the historic one came from 43 part numbers, not from one.
How do we do it?
1. Definition of geometry
We start with the circuit board drawing or physical sample: distance between holes, height of the component above the PCB, insertion length, and mounting orientation. If the component cannot be bent as required by the design without violating the minimum distance to the component, this is identified and an alternative is proposed.
2. Component preparation
Verification against specifications and inspection of terminal condition. Moisture-sensitive components undergo testing. baking and drying in accordance with IPC/JEDEC J-STD-033 if your MSL level requires it.
3. Formed
Use the tool and die specific to the geometry, not a universal tool. Hold the end piece, never the body. For complex geometries, forming is done in several steps, each with its own die.
4. Cut to length
When the design requires it, the terminal is cut to the insertion size after shaping, so that the reference is the fold and not the original end.
5. Inspection
Verification of the geometry against the drawing and of the terminal status, combining automatic inspection with our system Eyve, based on AI vision, and visual verification.
6. Packaging and delivery
The shaped component is packaged in protective packaging so that its geometry arrives intact at the insertion station. If the component requires it, in ESD bag with desiccant e humidity indicator.
Do you need to assemble components?
Send us the part number, quantity, and card drawing—or a sample of the assembled component—and we'll send you a proposal with the acceptance criteria that will be applied. Contact us.
Acceptance criteria
The electronics industry is highly regulated, and that works in the customer's favor: there's no need to negotiate what constitutes a well-made product; it's already defined. In this regard, the benchmarks are... IPC J-STD-001, which sets the limits of the shaping, and IPC-A-610 for the visual acceptance criterion and the relief of effort.
Each operation is executed under the applicable standard —IPC, JEDEC, EIA— and we have Certified personnel and internal IPC certifiersThe formation and verification of the criteria do not depend on a third party.
We agree in Guadalajara (Tlaquepaque, Jalisco) and Querétaro (The Colorado). The two plants provide national coverage and we have export capacity.
What comes before and what comes after the preform
The preform almost never arrives alone. Before forming, the moisture-sensitive components go through baking and drying to restore its MSL level. After that, most is delivered on tape and reel by taping of components, ready to power the SMT line. And when the device has firmware, the microphone programming It is done before assembly so as not to depend on test access in ICT.
Frequently Asked Questions
What is the difference between preform, preformed and lead forming?
None: they are the same process with three names. Lead forming It is the English term, and in the plant, preform and preformed are used interchangeably.
Do they consist of axial and radial components?
Yes, both. The axial type has the terminals on opposite ends of the body and almost always needs bending to fit into two separate holes; the radial type has them on the same side and usually needs less bending but more precise alignment.
How far can a terminal be bent?
The bend must start at least one body terminal diameter away, and never less than 0.8 mm, according to IPC J-STD-001. Beneath that distance, the internal seal of the component is at risk.
Do you work with my drawing or do you need a sample?
Either one will work. If you have the circuit board diagram, that's where you get the distance between holes and the height; if you only have the physical sample of the assembled component, that also serves as a reference.
Is there a minimum order quantity?
We treat a short, high-mix run the same as a sustained volume run. What we evaluate is the geometry, not the quantity.
Do they handle emergencies?
Yes. That's part of what outsourcing is for: absorbing the peak demand that your capacity can't handle.
What happens after the preform?
It depends on the destination. If the component is going to be fed automatically, it is usually delivered by taped on carrier tape. If it has firmware, the programming It is done before assembly. The preform is one of the thirteen operations in the catalog of value-added services.