1 Confidential Reliability of Spring Contacts n Basics of electrical spring contacts n Micro-vibration n Temperature cycling n Industrial atmosphere n Shock & Vibration

2 Confidential Comparison Spring contact / Solder contact General Considerations

3 Confidential SEMIKRON Standard Qualification Test Program Qualification Standards – SEMiX™

4 Confidential Failure Criteria for Module Qualification Qualification Standards - SEMiX™ R th(j-c)

5 Confidential SEMIKRON Additional Reliability Test Program Qualification Standards - SEMiX™

6 Confidential Contents n Basics of electrical spring contacts n Micro-vibration n Temperature cycling n Industrial atmosphere n Shock & Vibration

7 Confidential Types of electrical pressure contact contact force mating and unmating force Rc Basics on electrical spring contacts typ. 50N/mm² typ. 10N/mm² N/mm²

8 Confidential Plating systems for different pressure ranges nContact forces in pressure contacts of power modules: uMini SKiiP 5-6 N uSEMiX 3-5 N nMetallic platings (Mating/un-mating forces & contact forces): uSnPb or Sn N uAg N uNi / Au flash- 1-2 N uNi / AuCo 0.2%- 1-2 N Basics on electrical spring contacts

9 Confidential Electrical contact is formed by A-Spots (P. Slade, Electrical Contacts, 1999) Basics on electrical spring contacts

10 Confidential a-Spot radius on Cu for different currents (P. Slade, Electrical Contacts, 1999) Basics on electrical spring contacts

11 Confidential Different application ranges for electrical pressure contacts Basics on electrical spring contacts

12 Confidential MiniSKiiP II Contact spring MiniSKiiP contact spring: The contact springs for MiniSKiiP II are made of “K88”, a copper alloy by German supplier “Wieland”. Thickness of the spring material: 0.3 mm  0.05 mm The contact spring is silver plated. The thickness of that plating is varying over the springs surface and given in the sketch below. To reduce tarnishing, the silver plating is passivated by an additional inorganic conversion layer (SnCl2) or a metallic plating with a thickness << 1µm.

13 Confidential Contents n Basics of electrical spring contacts n Micro-vibration n Temperature cycling n Industrial atmosphere n Shock & Vibration

14 Confidential Tribometer Test – Schematic Set-up contact force piezo actuator spring pins fixing screw R clamping fixture PCB module housing mounting plate PCB IV DBC ΔRcΔRc Micro-vibration

15 Confidential Classification of micro-vibration test results Source: P.G.Slade: Electrical contacts: principles and application, Marcel Dekker, Inc. 1999, pp Micro-vibration

16 Confidential Tribometer (A) - Test equipment for micro-vibration Travel range  100 µm Frequencies  20 Hz Typical test conditions: µm 5-10 Hz Micro-vibration

17 Confidential Micro-vibration test result on Ag-Spring contact system Test conditions: Frequency: 1 Hz Amplitude: 50µm Sample Rate: 5s Cycles: 4,65 Mio. (Test time: ~54 days) Micro-vibration

18 Confidential Contents n Basics of electrical spring contacts n Micro-vibration n Temperature cycling n Industrial atmosphere n Shock & Vibration

19 Confidential General set-up of TC contact resistance tests PCB Al2O3 Cu Al SnPb IV R c1 R c4 R c2 R c3 DBC K88 Ag plated FR4 Initial R depends on R c of 4 pressure contacts current paths Experimental parameters Temperature cycling test: -40°C to +125°C During T-cycling: no current load on contacts R c test: 10mA, 5V voltage limitation in open circuit Testing current over a pair of spring pins  R c limit: 400m   per pair of spring pins (after 100 cycles) Temperature cycling of contact system

20 Confidential Temperature cycling results for contact resistance tests Temperature cycling of contact system Standard Lead PCB

21 Confidential Temperature cycling results for contact resistance tests Temperature cycling of contact system RoHS compatible

22 Confidential Temperature cycling results for contact resistance tests Temperature cycling of contact system

23 Confidential Contents n Basics of electrical spring contacts n Micro-vibration n Temperature cycling n Industrial atmosphere n Shock & Vibration

24 Confidential Corrosive atmosphere conditions ISA-S Standard: Environmental Conditions for Process Measurement and Control Systems: Airborne Contaminants There are four classes of industrial atmospheres with respect to copper reactivity. G1 – Mild An environment sufficiently well-controlled such that corrosion is not a factor in determining equipment reliability. G2 – ModerateAn environment in which the effects of corrosion are measurable and may be a factor in determining equipment reliability. G3 – HarshAn environment in which there is a high probability that corrosive attack will occur. These harsh levels should prompt further evaluation resulting in environmental controls or specially designed and packed equipment. GX – SevereAn environment in which only specially designed and packaged equipment would be expected to survive. Specifications for equipment in this class are a matter of negotiations between user and supplier. Industrial atmosphere

25 Confidential SEMiX with HAL SnPb PCB in industrial atmosphere IEC Atmosphere: 10 ppm H 2 S Temperature:25°C Relative humidity: 75 % Volume flow: >volume*3/h Duration:10 days No current load during storage Industrial atmosphere

26 Confidential SEMiX with HAL SnPb PCB in industrial atmosphere Corrosive atmosphere results: IEC Industrial atmosphere

27 Confidential Corrosive atmosphere test: SEMIKRON Conditions SEMIKRON Test Conditions Industrial atmosphere Atmosphere: 0.5 ppm NO ppm H 2 S 0.1 ppm Cl ppm NO 2 Temperature:25°C Relative humidity: 75 % Volume flow: >volume*3/h Duration:21 days No current load during storage

28 Confidential SEMiX with HAL SnPb PCB in industrial atmosphere Industrial atmosphere

29 Confidential Contents n Basics of electrical spring contacts n Micro-vibration n Temperature cycling n Industrial atmosphere n Shock & Vibration

30 Confidential Vibration Test (external test lab) - Test conditions Standard test conditions: Sinusoidal sweep Hz Hz: constant amplitude = 17.5mm (pp) Hz: constant acceleration = 5g 1 Octave/min.  6:40 min per sweep 20 sweeps per axis  2:20 hrs per axis Vibration & Shock on contact system

31 Confidential Vibration test (external test lab) – Monitoring for contact break Vibration & Shock on contact system Current Monitoring MV 200 Contact Monitoring (detects contact breaks >1µs) DUT 1 DUT 2 DUT n 10  100  10  100  10  100  +12V -

32 Confidential Vibration test (external test lab) – Test results SEMiX No contact interruption >1µs detected Vibration & Shock on contact system

33 Confidential Vibration test (external test lab) – Test results MiniSKiiP Vibration & Shock on contact system

34 Confidential Shock Test (external test lab) - Test conditions Standard test conditions: half-sinusoidal pulse peak acceleration 30g shock width 18ms 3 shocks in each direction (±x, ±y, ±z) 18 shocks in total Vibration & Shock on contact system

35 Confidential Vibration & shock test - Results MiniSKiiP ® II 6 devices tested I GES in spec. I CES in spec. V GE(th) in spec. V CE(sat) in spec. V iso 3.6kV o.k. R th(j-h) not tested (V F in spec.) Qualification of functional modules

36 Confidential Thank You Very Much For Your Kind Attention