How to Use Contact Probes
Single-Ended Contact Probes
Single-ended contact probes are vertically mounted and used in combination with sockets (also called receptacles). This configuration provides stable electrical contact and allows for easy probe replacement, making them ideal for general-purpose testing and long-term cost savings.
Probe Integration Process
- Drill holes in a resin or other base material that match the socket size.
- Insert sockets and connect lead wires (soldering optional).
- Insert contact probes into the sockets to complete the setup.
When the probe tips wear down, you can easily replace them without removing the entire fixture—minimizing downtime and maintenance costs.
Standard sizes & Customization
Seiken offers a full lineup of probes and sockets that support pitch sizes from 0.45mm to 4.75mm, each size includes standard tip shapes, but we also offer custom manufacturing for sizes and shapes not listed in our catalog to meet your specific requirements.
- * For fine-pitch applications below P = 0.45mm, double-ended probes are more effective.
Building a Probe Fixture with Single-Ended Probes
Begin by drilling holes in a resin base or similar board to match the socket size. You can find the recommended hole dimensions in our product catalog, or simply contact us for guidance.
Sockets are fixed into the base using either a press-fit method or two-part adhesives. For better height alignment, flanged sockets are recommended. For high-voltage testing, straight-type (ST) sockets are ideal for safety reasons.
To reduce wiring time, we offer sockets with pre-attached lead wires (100mm / 300mm), either crimped or soldered. Wire type and length can be customized to your specifications.
Finally, insert the contact probes into the mounted sockets.
If the tips become worn over time, only the individual probes need to be replaced—no need to replace the entire fixture, saving both time and cost.
- * For fine-pitch applications below P = 0.45mm, double-ended probes are more effective.
From Machining to Assembly — Your One-Stop Solution
At Seiken, we do more than supply individual components. We provide comprehensive support throughout the entire process—from resin hole machining and socket installation to wiring and final assembly. We also accept requests for specific parts of the process, such as machining-only services.
With decades of experience in probe and fixture manufacturing, we are committed to helping you build a high-quality, reliable testing environment—no matter the complexity of your requirements.
Double-Ended Contact Probes
Double-ended probes are not used with sockets. Instead, they are held in place by a probe head, which consists of multiple boards—typically a cover board, probe board, and guide board. This structure allows for fine-pitch layouts and high-density test configurations.
There are two types of double-ended probes:
- Both-End Actuating: Both plungers move independently.
- Single-End Actuating: One side is fixed, and the entire probe moves as one unit.
Both types can be integrated into the probe head.
Integrating Dual-Ended Probes into Test Fixtures
These probes are integrated into the fixture and connected via an interposer board (also known as an intermediate pin board), which applies preload pressure to ensure stable contact. We also provide design support for custom configurations, allowing you to select the most suitable interposer structure based on pin count and testing requirements.
Contact with DUT
The DUT is placed on the opposite end of the probe.
- In both-end actuating types, both plungers move for contact.
- In single-end actuating types, the entire pipe on the fixed plunger side moves.
Replacement and Maintenance
Probes can be individually removed and replaced using tweezers—simply detach the board on the interposer side and swap out the probe without disassembling the entire unit. This helps keep maintenance costs low.
Full Fixture Design Support
At Seiken, we offer more than just components—we provide end-to-end support to help you achieve highly accurate and stable testing environments. From fixture design and machining to precision wiring and assembly, we handle the entire process in-house. We also support custom machining of alignment pins, screw holes, and mounting features to match your testing setup.
With decades of experience in manufacturing high-precision probes for electronic and semiconductor applications, we have built a strong track record of supporting customers with a wide range of needs. We take pride in our ability to meet complex technical requirements through close collaboration and tailor-made solutions to meet even the most complex specifications.
Whether you're developing a new fixture or optimizing an existing one, we will work with you to find the best possible approach. Many of our clients come to us with very specific concerns, such as “I want to test this type of device,” “I need to make contact at this size or pitch,” or “Can this probe handle our unique test conditions?” We provide practical, effective answers based on our proven technology and flexible engineering capabilities.
If you are unsure about which type of probe or fixture is best suited to your application, we are here to help. Our team is ready to support you with solutions that are both reliable and customized to your testing challenges. Contact us today to find the right partner for your next project—you can count on Seiken.