Fast Power Thyristors – Series Overview, Specifications, Datasheets

What is Fast Power Thyristor?

Fast Power Thyristors, also known as Fast Turn-Off Thyristors, are semiconductors with reduced t_q, t_rr, Q_rr, E_RQ values.

Fast thyristors differ from phase control thyristors by high current carrying capacity at high frequencies up to 10 kHz and are used for operation at higher frequencies or in frequency-pulse modes.

The characteristics U_TM, t_q, Q_rr of the fast thyristor are related: a decrease in the value of t_q and Q_rr leads to an increase in U_TM.

To optimize the combination of U_TM, t_q, Q_rr, technological methods are applied that allow a controlled reduction of τ in the layers of the semiconductor chip: doping with atoms of heavy metals, irradiation with high-energy particles (γ-quanta, electrons, protons, alpha particles, etc.). Methods to control the p-emitter injection coefficient are also used.

To reduce t_q, a more efficient distributed cathode emitter shunt is also used (with smaller shunt spacings than for phase-control thyristors).

Optimal frequency range for using fast thyristors is up to 10kHz.

Since operation at higher frequencies is often accompanied by an increased speed at the front of the anode current pulses, fast thyristors have an increased di/dt-resistance and short turn-on time.

All disk-type thyristors presented on this site have a standard press-pack type ceramic housing. They are pressed with a relatively high force into heat-sinks which also serve as electrical contacts to the thyristor terminals.

Fast thyristors are available with forward current rating I_TAV ranges from 200A to 5000A, and the range of reverse blocking voltage V_RRM is from 400V to 4800V, and with t_q from 6.3 µs.

Fast Power Thyristors are popular used in high-power rectifiers, power supplies, metal smelting areas, induction heating furnace, smelting furnace, ARC furnace, vacuum furnace, thyristor frequency converter.

See also articles: Phase Control Thyristors (PCT), Fast Switching Thyristors, Thyristor Modules – Series Overview.

Series of Fast Thyristors in disc case design

Fast Thyristors TF series AS ENERGI^TM

Fast Thyristors TF series AS ENERGI^TM are press pack type fast turn-off thyristors, regulating and converting DC and AC currents from 200A to 2000A at frequencies up to 10 kHz in circuits with voltage ratings from 400V up to 3600V, and with t_q from 6.3 µs.

TF133...TF933

TF143...TF943

TF153...TF953

TF173, TF273

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Fast Thyristors TF133...TF933 (200A – 500A)

Type	IT(AV) (Tcase°C)	VDRM VRRM	ITSM	I2t	dv/dt	di/dt	tq	Tvj max	Rth(j-c)	Fm ±10%	W	Package	Dimensions ØDxØdxH	Data-sheet
	A	V	kA	kA2·s	V/µs	A/µs	µs	ºC	ºC/W	kN	g		mm	PDF
200 A
TF233-200	200 (102)	1000-1500	4.5	100	200-2500	1600	6.3-12.5	125	0.04	10	110	T.B2	42x25x14
TF433-200	200 (102)	1000-1500	4.5	100	200-2500	1600	6.3-12.5	125	0.04	10	180	PT32 (T.B3)	54x32x20
250 A
TF133-250	250 (94)	1600-2400	5.0	120	200-2500	1600	20-40	125	0.04	10	110	PT31-1 (T.B2)	48x27x15
TF233-250	250 (97)	1000-1500	5.4	140	200-2500	1600	8-16	125	0.04	10	110	T.B2	42x25x14
TF333-250	250 (86)	1600-2400	5.0	120	200-2500	1600	20-40	125	0.05	10	180 100	T.B3 PT31	54x32x20 47x27x15
TF433-250	250 (97)	1000-1500	5.4	140	200-2500	1600	8-16	125	0.04	10	180	PT32 (T.B3)	54x32x20
TF833-250	250 (94)	3000	5.7	162	1000	1000	50-125	125	0.04	10	180	PT32 (T.B3)	54x32x20
TF933-250	250 (92)	3000-3600	5.4	140	200-1000	1000	63-80	125	0.04	10	180	PT32 (T.B3)	54x32x20
320 A
TF133-320	320 (85)	1600-2400	6.0	320	200-1000	1600	25-50	125	0.04	10	110	PT31-1 (T.B2)	48x27x15
TF233-320	320 (90)	1000-1500	5.5	150	200-2500	1600	10-20	125	0.04	10	110	T.B2	42x25x14
TF333-320	320 (85)	1600-2400	6.0	170	200-1000	1600	25-40	125	0.05	10	180	T.B3	54x32x20
TF433-320	320 (90)	1000-1500	5.5	150	200-2500	1600	10-20	125	0.04	10	180	PT32 (T.B3)	54x32x20
400 A
TF133-400	400 (85)	1600-2400	6.6	210	200-1000	1600	50-63	125	0.04	10	110	PT31-1 (T.B2)	48x27x15
TF233-400	400 (85)	400-1400	6.5	200	200-1000	800	20-50	125	0.04	10	180	PT32	54x32x20
TF333-400	371 (85)	1400-2400	6.6	200	200-2500	1600	50-63	125	0.05	10	180 100	T.B3 PT31	54x32x20 47x27x15
500 A
TF333-500	500 (95)	300-1400	7.5	280	500-1000	500	32	125	0.035	10	100	PT31	47x27x15

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Fast Thyristors TF143...TF943 (400A – 630A)

Type	IT(AV) (Tcase°C)	VDRM VRRM	ITSM	I2t	dv/dt	di/dt	tq	Tvj max	Rth(j-c)	Fm ±10%	W	Package	Dimensions ØDxØdxH	Data-sheet
	A	V	kA	kA2·s	V/µs	A/µs	µs	ºC	ºC/W	kN	g		mm	PDF
400 A
TF143-400	400 (88)	1400-2200	8.0	320	200-1000	2000	25-50	125	0.034	15	240	PT42	60x38x20
TF243-400	400 (94)	1000-1500	9.5	450	200-2500	2000	10-20	125	0.03	15	180	PT41	57x35x14
TF943-400	400 (85)	3000-3600	7.5	600	200-1000	2000	50-63	125	0.034	15	240	T.C2	60x38x20
500 A
TF143-500	500 (85)	1400-2200	9.0	400	200-1000	2000	32-63	125	0.034	15	240	PT42	60x38x20
TF243-500	500 (91)	1000-1500	11.0	600	200-2500	2000	12.5-25	125	0.03	15	180	PT41	57x35x14
TF343-500	550 (85)	500-1100	9.0	800	500-1000	500	25	125	0.028	15	180	PT41	57x35x14
630 A
TF143-630	630 (80)	1400-2200	10.0	500	200-1000	2000	32-63	125	0.034	15	240	PT42	60x38x20
TF243-630	630 (84)	1000-1500	11.5	660	200-2500	200	16-32	125	0.03	15	180	PT41	57x35x14
TF343-630	630 (90)	400-1400	10.5	820	500-1000	500	32	125	0.028	15	180	PT41	57x35x14

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Fast Thyristors TF153...TF953 (630A – 1000A)

Type	IT(AV) (Tcase°C)	VDRM VRRM	ITSM	I2t	dv/dt	di/dt	tq	Tvj max	Rth(j-c)	Fm ±10%	W	Package	Dimensions ØDxØdxH	Data-sheet
	A	V	kA	kA2·s	V/µs	A/µs	µs	ºC	ºC/W	kN	g		mm	PDF
630 A
TF153-630	630 (85)	1400-2200	16.0	1200	200-1000	2000	20-40	125	0.021	26	550	PT53	75x51x26
TF253-630	630 (85)	800-1600	6.0	1600	200-1000	800	25-50	125	0.021	26	550	PT53	75x51x26
TF453-630	630 (94)	1400-2200	20.0	2000	200-2500	2000	20-40	125	0.021	26	550	T.D2	75x51x26
TF953-630	630 (90)	3000-3600	17.0	2400	200-2500	2000	50-63	125	0.021	26	550	T.D2	75x51x26
800 A
TF153-800	800 (85)	1400-2200	17.0	1445	200-1000	2000	20-50	125	0.021	26	550	PT53	75x51x26
TF253-800	800 (85)	800-1600	8.0	1900	200-1000	800	25-50	125	0.021	26	550	PT53	75x51x26
TF453-800	800 (86)	1400-2200	21.0	2200	200-2500	2000	20-40	125	0.021	26	550	T.D2	75x51x26
TF553-800	800 (85)	1400-2400	15.0	2630	1000	630	25-63	125	0.021	26	550	PT53-1	75x51x26
1000 A
TF153-1000	1000 (75)	1400-2200	18.0	1620	200-1000	2000	20-50	125	0.021	26	550	PT53	75x51x26
TF253-1000	1000 (85)	800-1400	10.0	2100	200-1000	800	25-50	125	0.021	26	550	PT53	75x51x26
TF453-1000	1000 (79)	1400-2200	22.0	2400	200-2500	2000	20-40	125	0.021	26	550	T.D2	75x51x26

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Fast Thyristors TF173, TF273 (1600A, 2000A)

Type	IT(AV) (Tcase°C)	VDRM VRRM	ITSM	I2t	dv/dt	di/dt	tq	Tvj max	Rth(j-c)	Fm ±10%	W	Package	Dimensions ØDxØdxH	Data-sheet
	A	V	kA	kA2·s	V/µs	A/µs	µs	ºC	ºC/W	kN	g		mm	PDF
1600 A
TF173-1600	1600 (95)	1600-2800	37.0	6800	200-1000	2500	50-63	125	0.008	45	1200	PT73	112x75x26
TF173-2000	2000 (90)	2000-2500	40.0	8000	200-1000	2500	40-63	125	0.008	45	1200	PT73	112x75x26
2000 A
TF273-2000	2000 (76)	1400-2400	40.0	9300	500-1000	1000	50	125	0.011	45	1200	PT73	112x75x26

Fast Thyristors KK series AS ENERGI^TM

Fast Thyristors KK series AS ENERGI^TM are available with current ratings from 200A to 4800A and blocking voltages from 800V to 4800V, and with t_q from 16 µs.

Type	IT(AV) (TC=70°C)	VDRM VRRM	ITSM	I2t	dv/dt	di/dt	tq	Tvj max	Rth(j-c)	Fm ±10%	W	Outline	Dimensions ØDxØdxH	Data-sheet
	A	V	kA	kA2·s	V/µs	A/µs	µs	ºC	ºC/W	kN	kg		mm	PDF
KK200
KK200-(12...14)	200	1200-1400	2.8	39	1000	200	20	125	0.08	5	0.10	A-1	42x25x15
KK300
KK300-(8...12)	300	800-1200	4.3	92	500	100	16-35	125	0.08	5	0.10	A-1	42x25x15
KK300-(12...14)	300	1200-1400	4.3	92	500	100	16-35	125	0.08	5	0.10	A-1	42x25x15
KK300-(14...20)	300	1400-2000	4.3	92	500	100	16-35	125	0.08	5	0.10	A-1	42x25x15
KK400
KK400-(8...16)	490	800-1600	4.3	92	500	1200	18-50	125	0.045	15	0.26	A-2	58x34x26
KK500
KK500-(12...14)	500	1200-1400	7.5	280	1000	200	20	125	0.045	15	0.26	A-2	58x34x26
KK500-(16...20)	500	1600-2000	7.0	250	1000	200	30	125	0.045	15	0.26	A-2	58x34x26
KK600
KK600-(12...20)	600	1200-2000	10.0	500	500	150	16-35	125	0.041	18	0.30	A-3	66x42x26
KK700
KK700-(8...18)	770	800-1800	9.0	405	500	1200	18-50	125	0.041	18	0.30	A-3	66x42x26
KK800
KK800-(8...20)	820	800-2000	9.0	405	500	1200	18-50	125	0.035	20	0.37	A-4	69x45x26
KK1000
KK1000-(8...18)	1080	800-1800	10.0	500	500	1200	18-50	125	0.020	22	0.47	A-5	74x47x26
KK1000-(25...30)	1000	2500-3000	12.0	720	1000	200	55	125	0.020	22	0.47	A-5	74x47x26
KK1200
KK1200-(12...14)	1247	1200-1400	16.0	1280	1000	1000	35	125	0.018	30	0.60	A-6	85x55x26
KK600-(12...20)	1205	1600-2000	15.0	1130	1000	1000	50	125	0.018	30	0.60	A-6	85x55x26
KK1300
KK1300-(8...18)	1330	800-1800	14.0	980	500	1200	18-50	125	0.018	30	0.60	A-6	85x55x26
KK1500
KK1500-(12...14)	1500	1200-1400	22.5	2500	1000	200	20	125	0.018	30	0.60	A-6	85x55x26
KK1500-(16...20)	1500	1600-2000	21.0	2200	1000	200	30	125	0.018	40	0.67	A-7	85x60x26
KK1500-(25...30)	1500	2500-3000	18.5	1700	1000	200	60	125	0.018	30	0.60	A-6	85x55x26
KK1600
KK1600-(8...12)	1600	800-1200	21.0	1620	500	1200	25	125	0.018	30	0.60	A-6	85x55x26
KK1600-(12...14)	1600	1200-1400	21.0	1620	500	1200	25	125	0.018	30	0.60	A-6	85x55x26
KK1700
KK800-(8...18)	1750	800-1800	18.0	1620	500	1200	18-50	125	0.018	30	0.60	A-6	85x55x26
KK1800
KK1800-(12...14)	1800	1200-1400	25.2	3200	1000	200	20	125	0.018	40	0.67	A-7	85x60x26
KK1800-(16...20)	1800	1600-2000	25.2	3200	1000	200	35	125	0.018	40	0.67	A-7	85x60x26
KK1800-(25...30)	1800	2500-3000	21.6	2300	1000	200	60	125	0.018	40	0.67	A-7	85x60x26
KK900
KK1800-(32...35)	1800	3200-3500	21.6	2300	1000	200	80	125	0.01	56	1.44	A-9	110x73x26
KK1900-(19...25)	1920	1900-2500	21.0	2205	500	1200	40-80	125	0.0125	45	1.0	A-8	100x63x26
KK2000
KK2000-(8...18)	2080	800-1800	21	2205	500	1200	18-50	125	0.0125	45	1.0	A-8	100x63x26
KK2000-(22...25)	2000	2200-2500	23	2205	500	100	16-35	125	0.0125	45	1.0	A-8	100x63x26
KK2000-(25...30)	2000	2500-3000	24.0	2900	1000	200	60	125	0.0125	45	1.0	A-8	100x63x26
KK2100
KK2100-(8...18)	2080	800-1800	21.0	2205	500	1200	18-50	125	0.0125	45	1.0	A-8	100x63x26
KK2100-(19...25)	2160	1900-2500	22.7	2576	500	1200	40-80	125	0.0125	45	1.0	A-8	100x63x26
KK2200
KK2200-(8...18)	2240	800-1800	23	2645	500	1200	30-60	125	0.0125	45	1.0	A-8	100x63x26
KK2400
KK2400-(12...14)	2400	1200-1400	33.6	5600	1000	200	22	125	0.0125	45	1.0	A-8	100x63x26
KK2500
KK2500-(12...18)	2500	1200-1800	35.6	6337	1000	250	40-80	125	0.01	56	1.44	A-9	110x73x26
KK2500-(20...22)	2500	2000-2200	35.6	6337	1000	250	40-80	125	0.01	56	1.44	A-9	110x73x26
KK2500-(25...30)	2500	2500-3000	30.0	4500	1000	200	60	125	0.01	56	1.44	A-9	110x73x26
KK2500-(32...35)	2500	3200-3500	30.0	4500	1000	200	80	125	0.007	70	1.4	A-11	120x84x26
KK2600
KK2600-(22...25)	2600	2200-2500	27	5600	500	1000	65	125	0.01	56	1.44	A-9	110x73x26
KK2700
KK2700-(19...25)	2790	1900-2500	33.8	5712	500	1200	40-80	125	0.01	56	1.44	A-9	110x73x26
KK2900
KK2900-(8...18)	2940	800-1800	35.6	6337	500	1200	30-60	125	0.01	56	1.44	A-9	110x73x26
KK3000
KK3000-(12...14)	3000	1200-1400	42.0	8800	1000	200	22	125	0.007	70	1.4	A-11	120x84x26
KK3000-(26...30)	3000	2600-3000	36.0	6500	1000	200	60	125	0.007	70	1.4	A-11	120x84x26
KK3200
KK3200-(41...48)	3290	4100-4800	35	6125	500	1200	80-150	125	0.007	70	1.4	A-11	120x84x26
KK3300
KK3300-(31...40)	3370	3100-4000	35	6125	500	1200	70-120	125	0.007	70	1.4	A-11	120x84x26
KK3600
KK3600-(16...20)	3600	1600-2000	50.4	12500	1000	200	40	125	0.01	56	1.44	A-9	110x73x26
KK3800
KK3800-(19...25)	3800	1900-2500	44.0	9680	500	1200	40-110	125	0.005	90	2.3	A-12	150x100x26
KK4000
KK4000-(25...30)	4000	2500-3000	48.0	12000	1000	200	60	125	0.005	90	2.3	A-12	150x100x26
KK4000
KK4000-(35...45)	4000	3500-4500	42	7500	500	1200	65	125	0.005	90	2.3	A-12	150x100x26
KK4200
KK4200-(41...48)	4290	4100-4800	44	9680	500	1200	80-150	125	0.005	90	2.3	A-12	150x100x26
KK4300
KK4300-(31...40)	4370	3100-4000	44	9680	500	1200	70-120	125	0.005	90	2.3	A-12	150x100x26
KK4400
KK4400-(8...18)	4470	800-1800	45	10125	500	1200	30-60	125	0.007	70	1.4	A-9	120x84x26
KK4800
KK4800-(19...30)	4890	1900-3000	62	19220	500	1200	40-120	125	0.005	90	2.3	A-12	150x100x26

Fast Thyristors VS-ST series Vishay Semiconductors

Fast Thyristors Vishay VS-ST series are available with current ratings from 330A to 940A and reverse blocking voltages from 400V to 1200V, and with t_q from 10 µs.

Type	ITAV/IFAV (TC)	VRRM VDRM	ITSM IFSM	I2t	VT(TO)	rT	Tvj max	Rth(j-c)	W	Package, Dimensions ØDxØdxH	Replacement AS ENERGITM	Data-sheet
	A (ºC)	V	A	kA2·s	V	mΩ	ºC	ºC/W	g	mm		PDF
VS-ST173C
VS-ST173C10CFK0	330 (55)	1000	4680	110	1.61	0.77	125	0.016	50	A-PUK (TO-200AB) 42x19x14	ASTD173C10CFK0
VS-ST173C10CFK1		1000									ASTD173C10CFK1
VS-ST173C10CFP0		1000									ASTD173C10CFP0
VS-ST173C10CFP1		1000									ASTD173C10CFP1
VS-ST173C12CFK0		1200									ASTD173C12CFK0
VS-ST173C12CFK0L		1200									ASTD173C12CFK0L
VS-ST173C12CFK1		1200									ASTD173C12CFK1
VS-ST173C12CFP0		1200									ASTD173C12CFP0
VS-ST173C12CFP1		1200									ASTD173C12CFP1
VS-ST183C
VS-ST183C04CFL0	370 (55)	400	4900	120	1.45	0.58	125	0.016	50	A-PUK (TO-200AB) 42x19x14	ASTD183C04CFL0
VS-ST183C04CFN0		400									ASTD183C04CFN0
VS-ST183C04CFN1		400									ASTD183C04CFN1
VS-ST183C08CFL0		800									ASTD183C08CFL0
VS-ST183C08CFL1		800									ASTD183C08CFL1
VS-ST183C08CFN0		800									ASTD183C08CFN0
VS-ST183C08CFN1		800									ASTD183C08CFN1
VS-ST203C
VS-ST203C10CFJ1	370 (55)	1000	5260	138	1.22	0.83	125	0.017	50	A-PUK (TO-200AB) 42x19x14	ASTD203C10CFJ1
VS-ST203C12CFJ0		1200									ASTD203C12CFJ0
VS-ST203C12CFJ1		1200									ASTD203C12CFJ1
VS-ST223C
VS-ST223C04CFL0	390 (55)	400	5850	171	1.09	0.82	125	0.017	50	A-PUK (TO-200AB) 42x19x14	ASTD223C04CFL0
VS-ST223C04CFL1		400									ASTD223C04CFL1
VS-ST223C04CFN0		400									ASTD223C04CFN0
VS-ST223C04CFN1		400									ASTD223C04CFN1
VS-ST223C08CFL0		800									ASTD223C08CFL0
VS-ST223C08CFL1		800									ASTD223C08CFL1
VS-ST223C08CFN0		800									ASTD223C08CFN0
VS-ST223C08CFN1		800									ASTD223C08CFN1
VS-ST303CL
VS-ST303C04LFK0	515 (55)	400	7950	316	1.48	0.56	125	0.010	250	B-PUK (TO-200AC) 58x34x27	ASTD303C04LFK0
VS-ST303C04LFL0		400									ASTD303C04LFL0
VS-ST303C08LFL1		800									ASTD303C08LFL1
VS-ST303C08LFN0		800									ASTD303C08LFN0
VS-ST303C08LFN1		800									ASTD303C08LFN1
VS-ST303C10LFJ0		1000									ASTD303C10LFJ0
VS-ST303C12LFH0		1200									ASTD303C12LFH0
VS-ST303C12LFJ1		1200									ASTD303C12LFJ1
VS-ST303C12LFK0		1200									ASTD303C12LFK0
VS-ST303C12LFK0L		1200									ASTD303C12LFK0L
VS-ST303C12LFK1		1200									ASTD303C12LFK1
VS-ST303C12LFK1L		1200									ASTD303C12LFK1L
VS-ST303C
VS-ST303C04CFL0	620 (55)	400	7950	316	1.48	0.56	125	0.010	83	E-PUK (TO-200AB) 42x25x14.5	ASTD303C04CFL0
VS-ST303C04CFL1		400									ASTD303C04CFL1
VS-ST303C04CFN1		400									ASTD303C04CFN1
VS-ST303C08CFK1		800									ASTD303C08CFK1
VS-ST303C08CFL1		800									ASTD303C08CFL1
VS-ST303C08CFN1		800									ASTD303C08CFN1
VS-ST303C10CFJ0		1000									ASTD303C10CFJ0
VS-ST303C10CFK0		1000									ASTD303C10CFK0
VS-ST303C12CCL1		1200									ASTD303C12CCL1
VS-ST303C12CFJ0		1200									ASTD303C12CFJ0
VS-ST303C12CFJ1		1200									ASTD303C12CFJ1
VS-ST303C12CFK0		1200									ASTD303C12CFK0
VS-ST303C12CFK0L		1200									ASTD303C12CFK0L
VS-ST303C12CFK1		1200									ASTD303C12CFK1
VS-ST303C12CFK1L		1200									ASTD303C12CFK1L
VS-ST333CL
VS-ST333C04LFL0	620 (55)	400	11000	605	0.93	0.58	125	0.010	250	B-PUK (TO-200AC) 58x34x27	ASTD333C04LFL0
VS-ST333C04LFL1		400									ASTD333C04LFL1
VS-ST333C04LFM0		400									ASTD333C04LFM0
VS-ST333C04LFM1		400									ASTD333C04LFM1
VS-ST333C08LFL0		800									ASTD333C08LFL0
VS-ST333C08LFL1		800									ASTD333C08LFL1
VS-ST333C08LFM0		800									ASTD333C08LFM0
VS-ST333C08LFM1		800									ASTD333C08LFM1
VS-ST333C
VS-ST333C04CFL0	720 (55)	400	11000	605	0.93	0.58	125	0.011	83	E-PUK (TO-200AB) 42x25x14.5	ASTD333C04CFL0
VS-ST333C04CFL1		400									ASTD333C04CFL1
VS-ST333C04CFM1		400									ASTD333C04CFM1
VS-ST333C08CFL0		800									ASTD333C08CFL0
VS-ST333C08CFL1		800									ASTD333C08CFL1
VS-ST333C08CFM0		800									ASTD333C08CFM0
VS-ST333C08CFM1		800									ASTD333C08CFM1
VS-ST733CL
VS-ST733C04LFL1	940 (55)	400	20000	2000	1.20	0.29	125	0.009	255	B-PUK (TO-200AC) 58x34x27	ASTD733C04LFL1
VS-ST733C04LFM1		400									ASTD733C04LFM1
VS-ST733C08LFL0		800									ASTD733C08LFL0
VS-ST733C08LFL1		800									ASTD733C08LFL1
VS-ST733C08LFM0		800									ASTD733C08LFM0
VS-ST733C08LFM0L		800									ASTD733C08LFM0L
VS-ST733C08LFM1		800									ASTD733C08LFM1

Air-cooled and Water-cooled heat-sinks for disc type thyristors

The operation of semiconductor devices at high currents and high reverse voltages is accompanied by high power in the p-n junction of the silicon chip.

Air and water heat sinks are used for cooling power SCR thyristors.

The heat sink is characterized by the value of power dissipation and the area of the cooling surface and is selected on the basis of the required heat dissipation at the operating power of the thyristor.

In disk-type thyristors, the necessary compression of the press contacts is provided only if they are assembled with heatsinks.

To keep electrical losses to a minimum and heat dissipation to a maximum, the necessary clamping force Fm must be provided during assembly.

Range of values of axial force on thyristor Fm, i.e. thyristor compression force, is from 10 to 100 kN depending on package diameter (housing type) and is specified in datasheet.

Heatsinks are used for disc (tablet type) semiconductors with сontact surface diameter from Ø19 mm to Ø100 mm.

See for more information about heatsinks for disc type SCR thyristors:
"Air-cooled heatsinks O series", "Air heatsink SF series", "Water heatsink SS series".

Installation recommendations for power disc type thyristors

The reliability of heat transfer and electrical contact between the mating surfaces of the thyristor and the cooler over the entire temperature range is ensured by appropriate torque (clamping force).

Before assembly you should perform visual inspection (1) contact surfaces for mechanical damages and wipe (2), soaked with alcohol (toluene, gasoline, acetone).

After inspection, fix the current contacts (leads), install a pin to fix the alignment of the structure.

To improve the parameters of heat transfer it is recommended to lubricate (3) a thin layer of silicone thermal conductive paste before the assembly, which is not a mandatory condition for installation.

Install the thyristor (3), the second part of the cooler, the fiberglass insulator and the thrust washer.

To thread the traverse (4) and evenly tighten the nuts. Make sure no misalignment and evenness of the contact surfaces.

When the parts are sufficiently clamped but moveable, we recommend placing the cooler on a flat surface and checking the tolerance for parallelism of the overall adjacent plane of the surfaces (5).

Clamp each nut in turn (about a quarter turn) to the stop (6). The amount of deflection of the traverse determines whether the achieved clamping force corresponds to the required one.

After installation, the fasteners (nuts and washers) must be additionally secured against corrosion.

Tips and recommendations for power thyristors:

The power thyristors should not be operated for long periods of time at their limit load for all parameters. In this case, the safety factor is determined by the required degree of reliability of the device.

Replace a failed power thyristor with a thyristor that matches the parameters of the one being replaced.

Supercooling must be provided when operating in an environment with an elevated ambient temperature.

Periodic cleaning of power thyristors and coolers to remove dust and contaminants is recommended to ensure proper heat dissipation.

Inductive current dividers (often twisted toroidal wire) should be used to equalize currents between power thyristors connected in parallel. The most popular connection methods are closed circuit, common coil circuit, or power thyristor. The efficiency of current dividers in this case is determined by the cross section of the magnetic wire.

Prevention of voltage unbalance when power thyristors are connected in series is achieved by using shunt resistors connected in parallel with each thyristor. Voltage equalization in transient conditions is provided by connecting capacitors in parallel to each thyristor.

It is strictly forbidden to touch power thyristors under high voltage during operation.