Probe Pin

 

Read More

Test Socket

 

Read More

Hand Socket Lid

 

Read More

LatestNews and Events

TTS Group is proud to be the Premier Sponsor of the…

TTS Group will be participating in the 1st Annual SWTest Asia…

TTS Group experienced three fruitful days of exhibiting and showcasing our…

TTS Group in Malaysia held a mock fire drill recently at…

Test Tooling Solutions Group shall be marking its 40th year next…

Study of Probe Pin Internal Resistance

Prepared by Takuto Yoshida
Presented at BiTS China Workshop, Suzhou on September 13, 2016

 

CRES Comparison by Pin Design

Pin Pitch: 0.8mm

Test Height: 2.5mm

Pin Design:

“A”: 10gf, 4‐point crimped PA

“B”: 25gf, 4‐point crimped PA

“C”: 42gf, 4‐point crimped PA

“D”: 28gf, Combined PA and Barrel

  • Higher pin force is lower CRES pin
  • Combined PA and Barrel pin (“D”) is the lowest CRES pin
  • CRES differ by pin design (18 mOhm to 33 mOhm)

CRES Composition in a Probe Pin

Note

PA: Plunger A (device side)
PB: Plunger B (PCB side)
BR: Barrel

Spring is removed from the drawing because it is no contribution to CRES path

Material Resistance

(1) PA material electrical resistance

(2) BR material electrical resistance

(3) PB material electrical resistance

Contact Resistance

(4) PA pad to PA contact resistance

(5) PA to BR contact resistance

(6) BR to PB contact resistance

(7) PB to PB pad contact resistance

Material Resistance

R: Electrical resistance (measured in ohms, Ω)

ρ: Electrical resistivity (measured in ohm⋅meters, Ω⋅m)

L: Length of material (measured in meters, m)

A: Cross-sectional area of material (measured in square meters, m2)

Total Material Resistance
R = 0.003 Ohm

  • Material resistance contribution is only 9% to 17%
  • Contact resistance is main player for pin CRES

Contact Resistance

  • R: Electrical resistance (measured in ohms, Ω)
  • Rc: Constriction resistance (measured in ohms, Ω)
  • Rf: Film resistance (measured in ohms, Ω)
  • Ro: Metal specific resistance (measured in ohms, Ω)
  • ρ: Electrical resistivity (measured in ohm⋅meters, Ω⋅m)
  • a: True contact area diameter (measured in meters, m)
  • σ: Film electrical resistivity (measured in ohm⋅meters, Ω⋅m)
  • d: Film thickness (measured in meters, m)
  • Constriction resistance contributor
    • Contact area shape
    • Contact force
    • Plating material and thickness
    • Hardness
    • Surface roughness
  • Film resistance contributor
    • Material
    • Thickness

Individual CRES Measurement

Source Meter Keithley 2400

  • Digital Multimeter Yokogawa 7555
  • PA Pad and PB Pad compress DUT
  • 3 small probes to contact DUT surface
  • R(PA Pad‐PA) = V1/0.1
  • R(PA‐BR) = V2/0.1
  • R(BR‐PB) = V3/0.1
  • R(PB‐PB Pad) = V4/0.1
  • Measure 10 times for each session with current of +0.1A and ‐0.1A by considering thermoelectric effect
  • Measured voltage was different by thermoelectric effect
  • Average voltage value for resistance calculation
New Pin Individual CRES

  • Pin Design “A” (10gf), “B” (25gf), “C” (42gf), “D” Combined PA and BR
  • Spring force is most to contact resistance of PA pad – PA, secondary for PB – PB pad
  • Combined PA and BR design for “D” design improve contact resistance of PA – BR
After 300K Cycle Individual CRES

  • Pin Design “A” (10gf), “B” (25gf), “C” (42gf), “D” (28gf) Combined PA and Barrel
  • Cycle effect mainly impact to contact resistance of BR – PB
  • Secondary impact to contact resistance of PB – PB pad
 

 

Pin Design “A” New vs. 300K

  • 300K cycle test effect mainly impact to contact resistance of BR – PB
  • Secondary impact to contact resistance of PA pad – PA
Pin Design “C” New vs. 300K

  • 300K cycle test effect mainly impact to contact resistance of PB – PB pad
  • Secondary impact to contact resistance of PA – BR
Pin Design “B” New vs. 300K vs. 3.5A 110hours

  • Current effect mainly impact to contact resistance of PB – PB pad
  • Secondary impact to contact resistance of BR – PB
  • Current effect is smaller than Pin Design “B”
  • Low temperature rise by current seems good for pin stability (Low CRES provide low heat (temperature rise))

Conclusion

  • Understand CRES Composition in a Probe Pin
  • Probe Pin CRES main player is contact resistance
  • We can measure each contact resistance by using 4‐wire measurement method
  • Higher pin force effective to reduce contact resistance of PA pad – PA
  • 300K cycle test impact to contact resistance of BR – PB (BR internal surface roughness and PB base shape seems big change)
  • 3.5A 110hours test impact to contact resistance of PB – PB pad
  • We feedback the probe pin design by result of individual CRES data

TESTIMONIALS

Price is lower, and the quality is good, compare the other product...in this price, the quality is good... I'm very happy to use your product...
Andy YangSnr Staff Engineer - Broadcom
Innovativeness, cost effectiveness and agility is the most important things we look for ...even after leaving Intel, I will always recommend TTS and will continue to do so.
Ashoke SethFormer Director - Intel
TTS socket is easy to use, great to put on, easy to remove and replace from board to board...
Paul WilliamsEngineering Tech - Broadcom
The reason to purchase TTS socket is not only low cost but high quality... perform in lab and to temperature testing.
Dale RasmusenPrincipal Engineer - Teknovus
...repeatability from trial to trial, and all in all, we have good support, certainly a robust product, so we are happy with it.
Christian WiherSenior Principal Engineer - Broadcom
The quality and design of sockets and pins are very good, my customers and business units are happy with the sockets. With that obviously we prefer TTS.
Errol MonsaleTest Hardware Engineer - IDT
The technology of TTS is novel and leading edge. I am excited from the information that is provided from this high technology company.
Akira NagashimaDirector - Toshiba
We are happy working with the Japanese team with great support. Let’s grow together.
SaitoDirector - Elia

WHAT'S INTERESTING

CAPABILITIES

PATENTS & AWARDS

CSR