4. BALANCE SHEET DETAIL - Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020
Prepaid expenses and other current assets:
Prepaid tooling and masks	$ 399	$ 707
Prepaid income taxes	76	79
Other receivables	213	211
Other prepaid expenses and other current assets	1,023	937
Total prepaid expenses and other current assets	$ 1,711	$ 1,934