Method of laser cutting a metal line on an MR head
US5759428A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Mar 15, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49032
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A thin film conductive line is formed between MR pads on an MR head for protecting an MR sensor from electrostatic discharge (ESD) during assembly steps between row level fabrication of the head and prior to merge of a head stack assembly with a disk stack assembly. The conductive line may have a reduced thickness delete pad. A laser beam having a fluence sufficient to sever the conductive line at the delete pad but insufficient to damage or cause debris from structure underlying or surrounding the conductive line is used to sever the conductive line. The method traverses minimum energy, short laser pulses at a high pulse rate across the width of the conductive line so that each laser pulse melts conductive material across the line, the melted material withdrawing from the melted area and being heaped on top of adjacent portions of the delete pad by surface tension and the melted material cooling to room temperature before the next pulse so that there is no cumulative heating and therefore no damage to or debris from the underlying structure. The conductive material of the line is incrementally plowed to each side of a severed path by successive overlapping laser pulses so that whe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.