Solder coated lid

Abstract

A solder coated lid for a package for an electronic device has a lead-free solder layer comprising a Sn—Sb based solder with a liquidus temperature of at least 220 degrees C. provided on at least a region of the lid where the lid is to be joined to a base of a package. The lid can be joined to a base of a package at a low temperature, thereby reducing vaporization of solder components and adhesion thereof to electronic devices within the package.

What is claimed is:  
     
         1 . A solder coated lid for a package for an electronic device having a lead-free solder layer comprising a Sn—Sb based solder with a liquidus temperature of at least 220 degrees C. provided on at least a region of the lid where the lid is to be joined to a base of a package.  
     
     
         2 . A solder coated lid as claimed in  claim 1  including a nickel layer formed beneath the solder layer.  
     
     
         3 . A solder coated lid as claimed in  claim 1 , wherein the lid is for a package for housing a quartz crystal unit.  
     
     
         4 . An electronic device package comprising a base having a recess, an electronic device disposed in the recess, and a lid according to  claim 1  covering the recess and sealed to the base by soldering.  
     
     
         5 . A package as claimed in  claim 4  wherein the electronic device comprises a quartz crystal unit.