6. ACCOUNTS RECEIVABLE, NET	9 Months Ended
Feb. 28, 2019
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
6. ACCOUNTS RECEIVABLE, NET	6. ACCOUNTS RECEIVABLE, NET Accounts receivable represent customer trade receivables and is presented net of allowance for doubtful accounts of $0 at February 28, 2019 and $4,000 at May 31, 2018. Accounts receivable are derived from the sale of products throughout the world to semiconductor manufacturers, semiconductor contract assemblers, electronics manufacturers and burn-in and test service companies. The Company’s allowance for doubtful accounts is based upon historical experience and review of trade receivables by aging category to identify specific customers with known disputes or collection issues. Uncollectible receivables are recorded as bad debt expense when all efforts to collect have been exhausted and recoveries are recognized when they are received.

6. ACCOUNTS RECEIVABLE, NET

9 Months Ended

Feb. 28, 2019

Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]

Accounts receivable represent customer trade receivables and is presented net of allowance for doubtful accounts of $0 at February 28, 2019 and $4,000 at May 31, 2018. Accounts receivable are derived from the sale of products throughout the world to semiconductor manufacturers, semiconductor contract assemblers, electronics manufacturers and burn-in and test service companies. The Company’s allowance for doubtful accounts is based upon historical experience and review of trade receivables by aging category to identify specific customers with known disputes or collection issues. Uncollectible receivables are recorded as bad debt expense when all efforts to collect have been exhausted and recoveries are recognized when they are received.