Note 5 - Revenue From Contracts With Customers - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net revenues	$ 21,820	$ 13,275	$ 41,376	$ 24,505
Semiconductor Market [Member]
Net revenues	15,677	6,858	28,997	11,869
Industrial Market [Member]
Net revenues	4,244	3,899	8,072	8,126
Defense/ Aerospace [Member]
Net revenues	1,268	1,496	2,397	2,904
Telecommunications Market [Member]
Net revenues	215	597	555	1,008
Other Multi Markets [Member]
Net revenues	416	425	1,355	598
Thermal Testing Products [Member]
Net revenues	4,537	3,703	8,842	7,850
Thermal Process [Member]
Net revenues	6,807	4,563	12,373	8,311
Semiconductor Production Test Products [Member]
Net revenues	8,954	3,665	17,274	5,489
Service and Other Products [Member]
Net revenues	1,522	1,344	2,887	2,855
End User [Member]
Net revenues	19,266	11,946	36,925	21,867
OEM and Integrators [Member]
Net revenues	$ 2,554	$ 1,329	$ 4,451	$ 2,638