Method of making pressure transducer and apparatus
View Patent ↗A method for making a pressure transducer comprising: forming a recess in a diaphragm, the diaphragm having a thinned region that deflects responsively to pressure being applied thereto; depositing a glass frit in the recess; embedding a plurality of strain gages in the glass frit; and, wire bonding the strain gages into a Wheatstone bridge configuration.
1. A method for making a pressure transducer comprising:
forming a recess in a diaphragm, the diaphragm having a thinned region that deflects responsively to pressure being applied thereto;
depositing a glass frit in the recess;
embedding a plurality of strain gages in the glass frit; and,
wire bonding the strain gages into a Wheatstone bridge configuration.
2. The method of claim 1 , wherein the forming comprising machining.
3. The method of claim 1 , further comprising firing the glass frit after depositing and prior to embedding.
4. The method of claim 1 , wherein the embedding comprises:
placing the plurality of strain gages on the glass frit; and,
firing the glass frit and strain gages.
5. The method of claim 1 , further comprising securing the diaphragm to a port.
6. The method of claim 1 , wherein the Wheatstone bridge configuration is a full bridge configuration.
7. The method of claim 1 , wherein the step of depositing glass frit comprises dispensing said glass frit into said recess using a paste dispenser.
8. The method of claim 7 , wherein said paste dispenser is a constant volume paste dispenser to provide a uniform thickness glass frit layer.
9. The method of claim 1 , wherein said strain gages are on a silicon die.
10. A pressure transducer comprising:
a diaphragm having a thinned region;
a recess in the diaphragm;
a glass frit in the recess; and,
a plurality of strain gages in the glass frit;
wherein, when a pressure is applied to the diaphragm, the thinned region deflects, and the resistance of the strain gages change responsively thereto.
11. The pressure transducer of claim 10 , further comprising a port coupled to the diaphragm.
12. The pressure transducer of claim 10 , wherein the diaphragm is metal.
13. The pressure transducer of claim 10 , wherein the strain gages are coupled in a Wheatstone bridge configuration.
14. The pressure transducer of claim 13 , wherein the Wheatstone bridge configuration is a full bridge configuration.
15. The pressure transducer of claim 10 , wherein the recess is smaller than the thinned region.
16. The pressure transducer of claim 15 , wherein the recess is in the thinned region.
17. The pressure transducer of claim 10 , wherein the strain gages are serpentine semiconductor strain gages.
18. The pressure transducer of claim 10 , further comprising wire bonds coupled to each of the strain gages.