Soldering a Connection Wire to UEBK Contact Pins / Contact Strips
Purpose and Scope
This instruction describes the correct manual procedure for soldering a connection wire to spring-loaded contact pins of the UEBK product family (contact strips / battery probes) from uwe electronic – regardless of the specific series (e.g. UEBK-1xx, UEBK-2xx, UEBK-3xx, UEBK-4xx, UEBK-5xx). The goal is a mechanically and electrically sound solder joint without damaging the spring inside the contact pin through heat input (loss of spring force/preload due to softening or annealing of the spring material).
UEBK Family Overview
| Product family | UEBK spring-loaded contact pins / contact strips (uwe electronic) |
| Pitch (centers) | approx. 2.54 mm to 7.00 mm, depending on series |
| Contact diameter | approx. 1.57 mm to 2.10 mm, depending on series |
| Number of pins | 2 to 6 pins, depending on the contact strip |
| Rated current | series-dependent, e.g. up to approx. 6.0 A |
| Termination | Solder connection (wire/lead) at the lower end of the contact pin |
Required Tools and Materials
- Temperature-controlled soldering station with a fine (conical/chisel-shaped) tip
- Solder wire (e.g. Sn60Pb40, or lead-free SAC alloy as required by your application) with flux core
- Fine tweezers or a crocodile clip to use as a heat sink
- Fixture or small vise to hold the contact pin
- Wire stripper, heat-shrink tubing if required
- Magnifier or microscope for visual inspection of the solder joint
Important Note on Protecting the Spring
The spring inside the contact pin must only heat up minimally during soldering.
The soldering iron may only touch the lower connection area (solder tab/wire terminal) of the contact pin – never the housing around the plunger/spring.
Use a heat sink (tweezers/clip) between the solder joint and the spring housing to interrupt heat flow toward the spring.
Solder for as short a time as possible (see temperature recommendation below) and avoid repeated reheating of the same joint.
Soldering Temperature
Recommended soldering temperature (manual soldering)
≈ 350 °C tip temperature on the soldering iron
Only brief contact (max. 2–3 seconds) with the connection area of the contact pin – never sustained contact.
Step-by-Step Procedure
- Clamp the contact pin in the fixture so that only the connection area is accessible and you do not accidentally apply pressure to the plunger/spring.
- Strip approx. 2–3 mm of the connection wire and pre-tin the wire ("pre-tinning") separately from the contact pin, to minimize the later soldering time on the component.
- Position fine tweezers or a crocodile clip as a heat sink between the solder joint and the spring housing.
- Set the soldering iron to approx. 350 °C tip temperature and wet the tip with a small amount of fresh solder to ensure good thermal contact.
- Touch the soldering tip briefly (max. 2–3 seconds) to the connection area (solder tab) of the contact pin, position the pre-tinned wire at the same time, and feed a small amount of solder until the joint flows cleanly.
- Remove the soldering iron immediately once the solder has flowed to a shiny finish – do not reheat or touch repeatedly.
- Let the joint cool undisturbed; do not move the wire or the contact pin while it cools.
- Visual inspection: shiny, smooth solder joint without a "cold" (dull grey, porous) appearance, no discoloration or deformation of the spring housing.
- Functional check: after cooling, manually check the travel and return force of the contact pin (or all pins of a contact strip) to confirm the spring has not been affected.
- If required, apply strain relief (e.g. heat-shrink tubing) over the solder joint.
Quality Control
- Solder joint shiny, concave, fully wetted
- No visible heat damage (discoloration, deformation) on the spring housing
- Spring travel moves smoothly and without sticking
- Mechanical pull test on the wire without the joint separating
Summary
Soldering temperature: approx. 350 °C on the soldering iron; limit contact time at the connection area of the UEBK contact pin to 2–3 seconds – regardless of the specific series. Use a heat sink between the solder joint and the spring, pre-tin the wire to minimize soldering time on the component, and always check spring function after soldering.
