Merits of LE SHEET
- Excellent through hole quality
(Less hole wall roughness, less wicking, less resin smear)
- Excellent hole position accuracy
- Stack heights can be increased
- Drill bit life will be prolonged
Effects of LE SHEET
LE SHEET is the entry sheet for mechanical drilling that consists of the lubricating layer and the aluminum sheet (70-150microns). The lubricant melts and covers the drill bit while drilling. And the smear occurring is prevented because the friction heat generation between the drill bit and the holes wall is prevented with this phenomenon. And also, the lubricants prevent the drill bits from wearing out and lengthen the life of the drill bits. Furthermore, the stack height can be increased and the drilling cost will be decreased with LE SHEET. Good quality through holes with less wall roughness and less micro crack between the glass fiber and the resin can be made with LE SHEET, because the debris can be smoothly discharged with the lubricant. In addition, the lubricant of LE SHEET is water soluble and easily removed by water rinse.
The improvement of the through hole quality is key factor for high density interconnect PWB manufacturing. And in the small diameter drilling, it becomes big concern to reduce the cost of drilling. Our LE SHEET meets the both demands.
Fig. 1 Construction of LE SHEET
Fig. 2 Drill Bit Temperature Change while Drilling