Feedthrough design and method for a hermetically sealed microdevice

A method of making a microdevice having a hermetically sealed cavity, the method comprising the steps of:

• providing a substrate having a top side and a bottom side;
• forming a first set of conductive traces on the top side of the substrate;
• forming an isolation layer over at least a portion of the top side of the substrate;
• forming a gap in the isolation layer that defines anchor points;
• forming a plurality of contact windows in the isolation layer to expose end portions of the first set of conductive traces;
• forming a second set of conductive traces on a portion of the isolation layer;
• forming a microstructure to the anchor points of the isolation layer and adjacent to the gap;
• providing a silicon cap having a first side, a second side, and a recess;
• and
• attaching the first side of the silicon cap to the isolation layer formed on the top side of the substrate such that the recess in the silicon cap houses the microstructure and forms the hermetically sealed cavity.

A microdevice having a hermetically sealed cavity to house a microstructure, the microdevice comprising:

• a substrate having a top side and a bottom side, the substrate having a plurality of electrically conductive vias, each via extending from the bottom side and terminating at a contact point at the top side of the substrate;
• a cap having a body portion and a sidewall, the sidewall extending outwardly from the body portion to define a recess in the cap, the cap attached to the top side of the substrate;
• and
• a plurality of via covers, each via cover attached to the top side of the substrate in a region around the contact point at the top side of the substrate to hermetically seal the via;
• wherein the microstructure is mounted within the hermetically sealed cavity, the hermetically sealed cavity being at least partially defined by the recess in the cap.

A method of making a microdevice having a hermetically sealed cavity, the method comprising the steps of:

• providing a cap having a first side and a second side, the cap made of silicon;
• forming at least one recess in the first side of the cap;
• providing a substrate having a top side and a bottom side, the substrate made of an electrically insulating material;
• forming a plurality of vias in the substrate that extend from the bottom side and to the top side, each via terminating at the top side of the substrate at separate contact points;
• forming a microstructure on the top side of the substrate;
• forming a plurality of conductive covers on the top side of the substrate at a region surrounding and covering the contact points;
• and
• attaching the first side of the cap to the top side of the substrate such that the recess in the cap houses the microstructure and the conductive covers to form the hermetically sealed cavity.

A microdevice having a hermetically sealed cavity to house a microstructure, the microdevice comprising:

• a substrate having a top side and a bottom side, the substrate having a plurality of conductive traces formed on at least a portion of the top side;
• a cap attached to the substrate and having a body portion, a sidewall, a plurality of posts, and a plurality of conductive vias, the sidewall extending outwardly from the body portion to define a recess in the cap, the plurality of posts extending outwardly from the body portion within the recess of the cap and in a spaced apart relationship from the sidewall, each conductive via formed within one of the plurality of posts and terminating at an outer end of each post;
• and
• a plurality of conductive members, each conductive member attached between at least one of the conductive vias and at least one of the conductive traces;
• wherein the microstructure is mounted within the hermetically sealed cavity, the hermetically sealed cavity being at least partially defined by the recess in the cap.

A method of making a microdevice having a hermetically sealed cavity, the method comprising the steps of:

• providing a cap having a first side and a second side, the cap made of an electrically insulating material;
• forming at least one recess in the first side of the cap, the recess defined by a sidewall that extend outwardly from a base portion of the cap, the recess having a plurality of posts within the recess, the posts in a spaced apart relationship from the sidewall;
• forming a via within each post, the via extending from the second side to the first side of the cap;
• providing a substrate having a top side and a bottom side, the substrate made of an electrically insulating material;
• forming a microstructure on the top side of the substrate;
• forming an outer sealing ring on the top side of the substrate;
• forming a plurality of conductive members on the top side of the substrate;
• and
• attaching the first side of the cap to the top side of the substrate with the outer sealing ring such that the recess in the cap houses the microstructure and the conductive members in the substrate enclose the vias in the cap, the attachment of the cap to the substrate forming the hermetically sealed cavity.