Effect of Rate of Voltage Rise 

on Reverse Breakdown of Silicon Diodes 

François Martzloff 

General Electric Company 

Reprinted from declassified General Electric TIS Report 63GL132, October 1963 

Significance

Part 5 –Monitoring instruments, laboratory measurements and test methods 

Part 7 – Mitigation techniques 

This declassified report is one of several prepared in the early sixties when industry was awakening to the 

sensitivity of semiconductors to transient overvoltages. One of the findings was that the so-called PIV 

rating of a diode did not reflect its transient withstand capability, hence the attention focused on that issue 

in this report. The finding of some upturn in the voltage breakdown confirmed the speculation that failure 

was a breakdown at the edge of the chip, while the PIV rating was related to the leakage across the bulk 

of the semiconductor. 

With a 40-year perspective, It is now only of historical interest that at the time (pre-MOV era) the 

protection of semiconductors was attempted with gaps. 
TECHNICA l INFORMATION SERIES 

GENERAL @ ELECTRIC 

rhe possibility that the level of reverse voltage breakiown increases with increased rate of voltage rise was 

investigated for two silicon diodes, IN679 and 4JA4. 

rhe IN679 samples were of the same lot with uniform PIV 

rating. The 4JA4 samples were from two lots with two 

iisttnct PIV ratings. 

NO. 63GL132 

DATE 10/14/63 

G.E. CLASS 11 

GOVT. CLASS 

None 

NO. PAGES 

AUTHOR 

FD 

2onc lus ions 

SUMMARY 

SUBJECT 

Transient overvoltages 

effect on rectifiers 

I. The voltage level at which failure occurs does 

increase with increased rate of voltage rise. 

~ITLE Effect of Rate of Voltage Rise on 

Reverse Breakdown of Silicon Diodes 

REPRODUCIBLE COPY FILED AT G.E. TECHNICAL DATA CENTER 

BLDG. 5, SCHENE'CTADY, N. Y. 

a) This is significant for only very short spikes 

(less than 0.1 ps) with protection. 

b) This makes possible a coordination of surge 

suppressors and rectifier characteristics 

2. There is little evidence that the.reverse voltage 

breakdown level under transient conditions is increased 

for an increased PPV rating in the 4JA4 diode. 

CEY WORDS 

Transient overvoltages, surges, rectifier breakdown 

AUTHOR F. D. Martzloff 

COMPONENT Electric Conversion Engineering 

APPROVED R. A. Koehler 
Time to breakdown 

If diode characteristic is flat, gap 

protects diode only down to this point. 

Faster rising surges will cause diode 

breadown before gap clamps the voltage. 

If diode characteristic is rising, protection is 

extended towards shorter, higher transients. 

Coordination of gap and diode characteristics 

Figure 1 
EFFECT OF RATE OF VOLTAGE RISE ON REVERSE BREAKDOWN OF SILICON DIODES 

I. INTRODUCTION 

Failure by reverse voltage transients in silicon rectifiers is 

believed to be caused by the breakdown of the junction surface. If 

this is true, we could expect their breakdown to show some of the characteristics of other insulation breakdown phenomena. In particular, 

there would be a rising volt-time characteristic, i-e,, breakdown 

occurring at increasing voltage within a decreasing time as the rate 

of voltage rise increases. 

Some surge suppressors, gaps, for instance, also exhibit a rising 

volt-time characteristic; this is to be expected as the suppressing 

action is obtained by breaking down the gas in the gap and releasing 

the energy in the resulting arc or in a series resistance. For this 

reason, gaps or other devices with rising volt-time characteristics are 

considered unsuitable for the protection of semiconductors against 

fast transients. 

However, if the breakdown of the semiconductor junction surface 

also has a rising characteristic, protection is extended toward shorter 

transients, as shown in Figure I. If on the other hand, the breakdown 

characteristic were flat, or worse, decrease (such as in the case of 

forward "dv/dt firing" of multi- junction devices), this would be a major 

restriction in the use of protectors with a rising volt time characteristic. 

In order to show whether or not such a rising characteristic exists 

for silicon rectifiers, two diode types, one with a diffused junction 

(1~679) and one with an alloyed junction (4~~4) were subjected to reverse 

voltage impulse, with increasing rate of voltage rise. 

-1- 
$5 CRO 

1: +I 

R1 adjusted from 25 ohms to 2,000 ohms to change time to crest 

land thus rate of rise) of the impulse. 

Test Circuit 

Figure 2 

Y-. - Diode under1 

10K test - 

T 

Variable .'-"_I n 

DC Supply 0.01 uF 0.01uF 
11. TEST CIRCUIT AND PROCEDURE 

A capacitor discharge surge generator was used to subject the 

diodes to an impulse voltage with controlled rate of voltage rise, and 

a long "tail". The impulse generator circuit is shown in Figure 2. 

The rate of voltage rise can be controlled by two factors: time to 

crest and crest voltage of the impulse wave. However, if failure occurs 

on the front of the wave, either or both factors can be varied to 

achieve the desired slope of the front of the wave. 

The diodes were subjected to the impulse at room temperature, with 

no other current flowing in the junction and no other voltage applied 

across the junction prior to or during the impulse application. 

The voltage across the diode was measured directly across the 

diode with a 551 Tektronix oscilloscope and P6913 high voltage probe. 

Oscillograms were taken for each shot, involving (48) IN679 diodes and 

(32) 4JA4 diodes. 

The IN679 diodes were specially selected by the Rectifier Components 

Department for uniform PIV rating (400 volts) and were obtained from 

one manufacturing lot. 

The 4JA4 diodes were also specially selected, for two uniform PIV 

ratings (200 and 600 volts) and were obtained from two manufacturing 

lots. 

Typical oscillograms of the failure at various points are reproduced in Figures 4 and 5 at the end of the report, respectively for the 

IN679 diode and the 4JA4 diode. These oscillograms show the sharp 

chopping of the voltage occurfng during the rising portion of the wave, 

whith one exception at 700v/ )IS where the failure occured on the tail. 
111. TEST RESULTS 

The complete test data are tabulated in the appendix. Only the 

average values are listed here 

Average rate of rise Average breakdown Average time to 

~olts/us Volts breakdown 

!-'s 

(not front of wave) 

1.5 

0.9 

0.6 

0.3 

0.12 

0.07 

0.05 

4JA4 Diode (all units from 2 lots and 2 PIV ratings) 

Average rate of rise Average breakdown Average time to 

~olts/ps Volts breakdown 

P s 

4JA Diode (at all voltage rise values) 

Sample Average breakdown, Volts 

200V PIV, Lot 1 . 1550 

200V PIV, Lot 2 1750 

200V PIV, Lots 1 and 2 1650 No strong statistical 

significance in the 

600V PIV, Lot 1 1840 difference observed here 

600V PIV, Lot 2 1770 

600V PIV, Lots 1 and 2 1800 
Time to breakdown - microseconds 

A X IN679 diode 

lo 4JA4 diode 

, Amperex Cat 4369 

Gap- 

(From TIS 62GL19 

Actual coordination of gap and diode characteristics 

Figure 3 
IV. DISCUSSION OF THE RESULTS 

Both diodes exhibit a rising characteristic (Figure 3), however, 

it rises very slowly until the time to breakdown decreases beyond 0.3 ps. 

This means that only extremely short spikes applied to diodes can reach 

a higher level without causing the breakdown of the diode. 

When compared to the volt-time characteristic of typical gaps 

(Figure 3), however, it seems that the upturn of the characteristic 

occurs in the same time range, i.e. 0.5 ps. Therefore, there is a 

good possibility that gaps can be applied to the protection of rectifiers. Of course, this should not be a conclusion to be applied without the knowledge of both characteristics, gap and diode, if a specific 

d&ode is to be protected by a specific gap. 

On the other hand, the results obtained with two different PIV 

ratings on the 4JA4 diode do not show strong statistical evidence that 

the 600 volt diode can withstand higher transient over-voltage than 

the 200 volt diode. At most, the gain is in the order of 8% for a 

three-fold increase in PIV. 

There is no evidence of difference between manufacturing lots on 

the 4 JA4 diode. 

V. CONCLUSIONS 

1. The failure level of both diodes does indeed increase when the 

rate ol voltage rise increases. However, this increase is only 

significant for spikes of less than 0.1 ps duration. 

2. When surge suppressors are applied, the fact that they have a 

rising volt-time characteristic is not irrevocably objectionable 

since the diodes also have a rising characteristic. However, only 

careful matching of the characteristics would provide safe protection in specific applications. 

3. For the alloyed junction diode, 4JA4, there is little evidence of 

increased surge withstand capabi1ity"with increased PIV rating. 
Appendix - Test Data 

IN679 Diode Failure levels, standard deviations, and time to breakdown. 

4 ps to crest wave 2 us to crest wave 

- 1450 V - 1500 V - 1500 V - 1600 V 

1400 V Avg. 1450 V Avg. 1500 V Avg. 1650 V Avg. 

(Std. dev. 68 V) (Std. dev. 60 V) (Std. dev. 150 V) . (Std. dev. 175 V) 

Breakdown in tail Breakdown in 1.5 ps Breakdown in 0.9 1s Breakdown in 0.6 ps 

0.6 to crest wave 0.1 us to crest wave 

- 1900 V - 1800 V - 2400 V 2300 V 

1750 V Avg. 1675 V Avg. 2350 V Avg. 2450 v Avg. 

(Std. dev. 120 V) (Std. dev. 160 V) (Std. dev. 140 V) (Std. dev. 160 V) 

,Breakdown in 0.3 ps Breakdown in 0.1 ps Breakdown in 0.07 ps Breakdown in 0.05 ps 

NOTE: There is no significant difference from one level to the next except between 

20 KV/ps and 30 KV/ps, however, a trend towards increasing levels from 700 V/ps 

to 20 KV/~S is apparent. 

4JA4 Diode Failure levels, standard deviations, and time to breakdown. 

1000 Vlps 1500 V/ps 5000 V/ps 30000 V/ps Avg . 200 V Lot 1 1100 V I1 11 1200 v 

200 V Lot 2 1300 V I1 11 1500 V 

600 V Lot 1 1400 V I1 I1 1600 V 

600 V Lot 2 '1600 V I1 I1 

NOTE : 

- 1400 V 

1400 V Avg. 

1100 

1500 

1000 

2500 

1600 

1500 

1500 

- 1500 

1530 V Avg. 

1400 

14 00 

1200 

1500 

1600 

1700 

1300 

- 1700 

1520 V Avg. 

2400 

2400 

2500 

2600 

2500 

2700 

2600 

- 2600 

2530 V Avg. 

(Std. dev. 170 V) (Std, dev. 400 V) (Std, dev. 140 V) (Std. dev. 95 V) 

Breakdown in 1.5 ps Breakdown in 1 ~s Breakdown in 0.3 ps Breakdown in 0.08 ps 

The difference between Lots 1 and 2 at 200 volts is mostly due to one exceptional 

sample at 2500 volts, and is not significant. 

The difference of 150 volts between the combined 200 and 600 volts Lots is barely 

significant and only represents an 8% increase for a 3 to 1 increase in PIV. 
700 V/ps rate of rise 

1,500 ~/ps rate of rise 

5,000 V/ps rate of rise 

30,000 ~/ps rate of rise 

Breakdown of 1N679 diode at four different rates of voltage rise 

Voltage measured across diode subjected to surge. 

Figure 4 

Time Scale 2 psldiv 

Voltage Scale 500 V/div 

Time Scale 0.5 ps/div 

Voltage Scale 500 V/div 

Time Scale 0.2 psldiv 

Voltage Scale 500 V/div 

Time Scale 0.1 ws/div 

Voltage Scale 1000 V/dFv 

(trace reinforced for 

reproduction except at 

arrow showing the peak) 
1,000 ~/ps rate of rise 

Time Scale 1 ps/div 

Voltage Scale 500 V/div 

Time Scale 1 ps/div 

Voltage Scale 500 V/div 

1,500 V/ps rate of rise 

0- 

Time Scale 0.2 ps/div 

Voltage Scale 500 V/div 

(trace reinforced for 

reproduct ion) 

5,000 V/ps rate of rise 

Time Scale 0.1 ps/div 

Voltage Scale 1000 ~/div 

(trace reinforced for 

reproduction) 

30,000 v/ps rate of rise 

Breakdown of 4JA4 diode at four different rates of voltage rise 

Voltage measured across diode subjected to surge. 

Figure 5