| Root Part Number |
Test Center in. (mm) |
| LTP-1 | .075 (1.97) |
| SPA-3 | .125 (3.18) |
| SPA-4 | .187 (4.75) |
| SPA-5 | .187 (4.75) |
Proven performance, ISO-9000-registered quality and direct technical support have made ECT spring probes the first choice of test engineers worldwide. For the fastest possible response, we offer the world's largest selection of off-the-shelf spring probes and same-day shipping of most orders. Extensive in-house engineering and manufacturing resources enable us to deliver custom probe designs in weeks instead of months.
Technical Notes:
SMT Pointing Accuracy
Figure 1 illustrates pointing accuracy, defined as the radial play of the plunger tip measured from the centerline of the probe mounting hole. It is the result of a tolerance stack-up of the probe and receptacle assemblies.
Probes are manufactured to exacting tolerances to minimize radial play and ensure consistent, repeatable tip-to-target accuracy. The HPA-62 and HTP-62 series offer a receptacle with a double press ring to optimize perpendicularity and enhance pointing accuracy.
Pointing accuracy is significantly affected by a variety of other manufacturing tolerance factors. These include: angle of the probe mounting hole, probe plate warp, fixture-to-UUT registration, tooling hole/pin registration, etc
Pointing accuracy specifications for our SMT probes are based solely on their mechanical limitations. The probes are designed to test SMT boards manufactured in accordance with testability guidelines established by the Surface Mount Technology Association (SMTA) as of this printing. SMTA studies recommend a minimum size of 0.035 inches for test pads to ensure probe-to-target contact. Testability guidelines are available from SMTA, in Edina, MN.
Fastite® Termination
Figure 2 illustrates the Fastite® termination. It offers the lowest fixture wiring cost for 0.050 inch test center receptacles. The design combines a quick wire-insertion slot in the termination end of the receptacle with a precision-molded dielectric sleeve that reinforces the connection, eliminates strain and prevents electrical shorting. It can be easily re-moved in case of wiring errors. See Fastite® termination tips in the Tools section.