On high speed precision blanking of IC lead-frames using a progressive die
✍ Scribed by Takashi Jimma; Fumitaro Sekine
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 692 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0924-0136
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✦ Synopsis
The factors affecting the dimensional accuracy of blanked IC lead-frames are discussed. Attention is focussed on the elimination of the residual stress in the material caused by roll-slitting. Improvement in the designing and manufacturing of the blanking tool is explained and the mechanism of vibration of the stripper in high-speed blanking is analyzed. A high speed precision press that has been developed in Japan is introduced. The effects of blanking conditions such as tool clearance, strip-holding force, lead-shape, and order of blanking are explained, using a newly proposed mechanical model. TABLE 2 Factors affecting the dimensional accuracy of leads 293 1 The mechanical properties of the strip materials 2 The residual stresses of the strip materials after temper-rolling, roll-slitting and straightening 3 The static and dynamic accuracy of the presses and the blanking tools 4 The accuracy of the feed 5 The slenderness of the punch 6 The wear of the tools 7 The lubricant 8 The blanking speed 9 The strip-holding force 10 The order of blanking 11 The shapes of curved leads 12 The ratios of the length and the width to the thickness of leads