Electrically-isolated interconnects and seal rings in packages using a solder preform

Abstract

Embodiments include electronic assemblies and methods for forming electronic assemblies. One embodiment includes a method of forming a MEMS device assembly, including forming an active MEMS region on a substrate. A plurality of bonding pads electrically coupled to the active MEMS region are formed. A seal ring wetting layer is also formed on the substrate, the seal ring wetting layer surrounding the active MEMS region. A single piece solder preform is positioned on the bonding pads and on the seal ring wetting layer, the single piece solder preform including a seal ring region and a bonding pad region. The seal ring region is connected to the bonding pad region by a plurality of solder bridges. The method also includes heating the single piece solder preform to a temperature above the reflow temperature, so that the bridges split and the solder from the preform accumulates on the seal ring wetting layer and the bonding pads. A lid is coupled to the solder. In certain embodiments the lid may include vias having conductive material therein for providing electrical contact to the MEMS device. Other embodiments are described and claimed.

1 . An electronic assembly comprising: 
 an active MEMS region on a substrate;    a plurality of bonding pads electrically coupled to the active MEMS region;    a seal ring wetting layer on the substrate, the seal ring wetting layer surrounding the active MEMS region;    a solder seal ring on the seal ring wetting layer;    solder bonding pad interconnects on the bonding pads;    a lid coupled to the solder seal ring and to the solder bonding pad interconnects;    a plurality of vias extending through the lid and positioned in alignment with the solder bonding pad interconnects; and    an electrically conductive material in the vias that is electrically coupled to the solder bonding pad interconnects.    
   
   
       2 . An electronic assembly as in  claim 1 , wherein the bonding pads and the seal ring wetting layer are formed from the same material.  
   
   
       3 . An electric assembly as in  claim 1 , further comprising a wetting layer formed on a portion of the lid, the wetting layer on the lid being in contact with the seal ring and with the solder bonding pad interconnects.  
   
   
       4 . The electronic assembly of  claim 1 , wherein the substrate and the lid each comprise silicon.  
   
   
       5 . The electronic assembly of  claim 1 , wherein the solder material comprises gold and tin.  
   
   
       6 . An electronic assembly comprising: 
 an electronic device on a substrate;    a plurality of bonding pads electrically coupled to the electronic device;    a seal ring wetting layer on the substrate, the seal ring wetting layer surrounding the electronic device;    a solder layer positioned on the seal ring wetting layer surrounding the electronic device;    a solder layer positioned on the bonding pads; and    a lid positioned to cover the electronic device;    wherein the seal ring wetting layer and the bonding pads are formed from the same material.    
   
   
       7 . The electronic assembly of  claim 6 , wherein the lid is coupled to the solder layer positioned on the seal ring wetting layer.  
   
   
       8 . The electronic assembly of  claim 6 , wherein the solder layer positioned on the seal ring wetting layer and the solder layer positioned on the bonding pads are formed from the same solder material, and wherein the lid is coupled to the solder layer positioned on the seal ring wetting layer and to the solder layer positioned on the bonding pads.  
   
   
       9 . The electronic assembly of  claim 6 , wherein the substrate and the lid each comprise silicon.  
   
   
       10 . The electronic assembly of  claim 8 , wherein the solder material comprises gold and tin.  
   
   
       11 . The assembly of  claim 6 , wherein the electronic device is a MEMS device.