Process of measuring coplanarity of circuit pads and/or grid arrays
US5734475A · kind A · utility
15Cited by
7References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1996 |
| Grant date | Mar 31, 1998 |
| Priority date | — |
| Expiry date | Oct 15, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K13/0813
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A process of measuring coplanarity of an array of conductive elements on a circuit device is disclosed. Light is impinged from a reference plane onto an element of the array at a predetermined angle of incidence. Light is also impinged from the reference plane onto a reflective feature on a measurement plane determined by three points of the circuit device having highest elevations from a base of the circuit device, at the same predetermined angle of incidence. A response of the light impinged onto the element of the array and the reflective feature on the measurement plane is measured to determine coplanarity of the array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.