『爪』 in technical material is used to describe any type of clamp, pincer, bracket or jaw on a device.

So the sentence is saying:
基板を固定し、チップ部品を試験用爪で加圧し、引き剥がし力を測定する

Secure the plate and measure the peeling / bonding strength while applying pressure to the chip area with the testing clamp.

...something like this. You might have a more appropriate word for 引き剥がし力 than 'peeling' or 'bonding' strength.

Hope this helps.

Good luck!