| 摘要 |
<p>The present invention employs a programmable rotary cam to fold leads of a semiconductor package from their initial positions to their final specified shape without leaving any scratch mark except the initial cam punch radius mark at the foot area of the leads. The centre of cam rotation is determined by three contact points - the contact points of the cam punch with the lead at the final lead position 95, at the initial lead position 85, and an intermediate lead position 90. Once the semiconductor package is clamped between the lower anvil and the upper clamping support, the rotary cam is lowered to a location corresponding the the centre of cam rotation. The cam punch 115 rotates and guides the leads into its final form when the inner surface of the cam punch meets the outer surface of the lower anvil. The present invention thus eliminates scratch marks on the leads from semiconductor packages. The programmable cam punch of the present invention also achieves the mean of lead specification regardless of material and plating thickness of the lead. In the preferred embodiment of the present invention, the cam punch is coupled to a servo motor such that the spring back factor of the lead material can be detected and compensated. <IMAGE></p> |
