Chip on submount carrier fixture

Abstract

Heat assisted magnetic recording uses a laser diode (LD) to provide energy during the writing process. The LD is bonded on a submount chip which is referred to as the Chip-On-Submount-Assembly (COSA). COSA devices undergo burn-in and testing in COSA burn-in fixtures, which include a first non-conductive layer having through holes and a second conductive layer having first openings. The second conductive layer is disposed over the first non-conductive layer with each of the first openings overlaying one of the through holes. COSA burn-in fixtures also include a third non-conductive layer having second openings that are larger than the first openings. The third non-conductive layer is disposed over the second conductive layer with each of the second openings overlaying one of the first openings, which forms pockets with a seat on the conductive layer for disposing the LD with one electrode in contact with the conductive layer.

What is claimed is: 
     
         1 . A system comprising:
 a plurality of laser diode submount assemblies, each laser diode submount assembly comprising a laser diode (LD) with a first contact disposed on a submount with a second contact;   a holder that holds the plurality of laser diode submount assemblies, comprising:
 a first non-conductive layer having a plurality of through holes; 
 a second conductive layer having a plurality of first openings, the second conductive layer being disposed over the first non-conductive layer; 
 a third non-conductive layer having a plurality of second openings that are larger than the plurality of first openings, the third non-conductive layer being disposed over the second conductive layer with each of the plurality of second openings overlaying one of the plurality of first openings; and 
   wherein the plurality of first openings and the plurality of second openings form a plurality of pockets with a seat on the conductive layer, the plurality of submount assemblies being disposed within the plurality of pockets with the second contact of the submount making electrical contact with the second conductive layer at the seat and each LD being disposed within one of the first openings.   
     
     
         2 . The system of  claim 1  further comprising a plurality of third opening in the first non-conductive layer, each of the plurality of third openings extending from the an edge of the first conductive layer to one of the through holes. 
     
     
         3 . The system of  claim 2  wherein each of the third openings provides a path for light produced by the LD, when the LD is powered, to exit the system. 
     
     
         4 . The system of  claim 1  wherein all of the submounts share a common second contact. 
     
     
         5 . The system of  claim 1  wherein the diameters of the first openings are larger than the diameters of the through holes. 
     
     
         6 . The system of  claim 1  wherein each of the plurality of through holes is centered with respect to each of the plurality of first openings. 
     
     
         7 . The system of  claim 1  wherein each of the plurality of through holes is centered with respect to each of the plurality of first openings and each of the plurality of second openings is centered with respect to each of the plurality of first openings. 
     
     
         8 . The system of  claim 1  wherein electrical contact to the first contact on the LD is made through the through-hole in the first conductive layer. 
     
     
         9 . The system of  claim 1  wherein the LD has an LD height and the second conductive layer has a first thickness greater than the LD height. 
     
     
         10 . The system of  claim 1  wherein the submount has a submount height and the third non-conductive layer has a second thickness less than the submount height. 
     
     
         11 . The system of  claim 1  further comprising a base in contact with a back side of the submount opposite the side of the submount where the LD is disposed, the base being attached to the first non-conductive layer, the second conductive layer and third non-conductive layer to hold the plurality of submount assemblies together and apply force between second contact on the submount and the second conductive layer at the seat. 
     
     
         12 . The system of  claim 11  wherein the base is attached to the first non-conductive layer, the second conductive layer and third non-conductive layer via a clamp. 
     
     
         13 . The system of  claim 11  wherein the first contact is a p-contact and the second contact is an n-contact. 
     
     
         14 . A method comprising:
 providing a first non-conductive layer having a plurality of through holes;   stacking a second conductive layer over the first non-conductive layer, the second conductive layer having a plurality of first openings; and   stacking a third non-conductive layer having a plurality of second openings that are larger than the plurality of first openings over the second conductive layer with each of the plurality of second openings overlaying one of the plurality of first openings;   wherein the plurality of first openings and the plurality of second openings form a plurality of pockets with a seat on the conductive layer;   providing a plurality of laser diode submount assemblies, each laser diode submount assembly comprising a laser diode (LD) with a first contact disposed on a submount with an second contact;   disposing the plurality of laser diode submount assemblies in the plurality of pockets with the second contact of the submount making electrical contact with the second conductive layer at the seat and each LD being disposed within one of the first openings.   
     
     
         15 . The method of  claim 14  further comprising:
 providing a base; and 
 pressing together the plurality of second contacts on the plurality of submounts with the second conductive layer at the seat by attaching the base to the first non-conductive layer, the second conductive layer and third non-conductive layer. 
 
     
     
         16 . The method of  claim 14  further comprising providing power to the plurality of LDs and detecting light produced by the plurality of LDs through a plurality of third openings in the first non-conductive layer, each of the third openings extending from an edge of the first conductive layer to one of the through holes.