Transducer glass bonding technique
AssigneeDresser Industries, Inc.
InventorWilliam S. Kosh
Life of this patent
Estimating the term…
Abstract
A polyimide adhesive is applied in liquid form between surfaces of a pressure transducer glass surface and a glass pedestal tube and maintained at room temperature, or below, for a period of 10-15 hours to allow the adhesive solvent to evaporate. After such time, the temperature of the transducer and attached pedestal tube is elevated over a period of time to about 320.degree. C. to completely imidize the polyimide adhesive. The pedestal is then fixed within an opening in a base portion of a case, and electrical conductors are connected between pins in the case and transducer contacts. A cover is hermetically sealed to the case to thereby encase the transducer.
Claims41
A method for bonding a glass tube to a glass surface of a transducer, comprising the steps of:
- applying a solvent-containing polyimide adhesive to a surface of said glass tube, said polyimide adhesive being at room temperature, or below when applied;
- placing the adhesive applied surface of said glass tube onto the glass surface of said transducer to form a composite structure;
- maintaining said composite structure at about room temperature or below, for a sufficiently long period of time to allow substantially all of the solvent to escape;
- and
- thereafter raising the temperature of the composite structure to a temperature sufficient to cure the polyimide adhesive to realize a substantially void-free thermosetting bond.
A method for bonding a transducer having an apertured glass layer, to a glass tube, comprising the steps of:
- coating a surface of the glass tube for the transducer glass layer with a liquid polyimide adhesive;
- applying a predetermined pressure between the glass tube and the transducer glass layer so that a thin layer of said adhesive is formed;
- maintaining the thin polyimide layer at room temperature, or below, for a period of time sufficient to allow substantially all of an adhesive solvent to evaporate;
- and
- elevating a temperature of the transducer and attached glass tube such that complete imidizing of the polyimide adhesive occurs.
A method for fabricating a transducer device, comprising the steps of:
- coating at least one surface of a transducer assembly or a glass pedestal with an adhesive composition composed of the reaction product of 3, 3' -diaminobenzophenone and 3, 3', 4, 4' benzophenone tetra-carboxylic acid dianhydride;
- resting the pedestal upon the transducer assembly so that a thin layer of said adhesive is formed therebetween;
- maintaining the temperature of said adhesive at less than about 10.degree. C. for a period of about 10-15 hours for allowing substantially all of an adhesive solvent to evaporate from said polyimide adhesive;
- elevating the temperature of said transducer assembly and attached glass pedestal for a period of about 3-8 hours to a final temperature of greater than about 300.degree. C.;
- fixing said pedestal and attached transducer assembly to a base of a case;
- forming at least one fluid inlet to said case;
- bonding conductors between pins of said case and contact surfaces of said transducer assembly;
- and
- hermetically sealing a cover to the base of said transducer case.
A method for assembling a transducer structure, comprising the steps of:
- bonding a pedestal tube to a transducer assembly such that a channel is defined for communicating fluids to said transducer assembly;
- fixing the pedestal tube in a base portion of a case having electrical feed through pins;
- connecting conductors between said feed through pins and contact surfaces of said transducer assembly;
- and
- hermetically sealing a cover to said case for encasing said transducer assembly.
A method for bonding a transducer assembly to a pedestal tube, comprising the steps of:
- applying a polyimide adhesive at room temperature or below, to a surface of said transducer assembly or to said pedestal tube;
- resting said pedestal tube on said transducer assembly to form a thin layer of said adhesive therebetween;
- maintaining said polyimide adhesive layer at said low room temperature or below until substantially all of an adhesive solvent has evaporated therefrom;
- and
- elevating the temperature of said adhesive layer sufficient to imidize said polyimide adhesive and securely bond said pedestal tube to said transducer assembly.
A method for assembling transducer parts together, comprising the steps of:
- applying a liquid polyimide adhesive to one or the other of a transducer chip and one end of a pedestal tube;
- placing the parts together by butting the one end of the pedestal tube against a planar surface of the transducer chip while the polyimide adhesive is yet a liquid so that a fillet of the adhesive is formed on a sidewall of the other of the chip or tube;
- allowing the polyimide adhesive to remain at a low temperature until a solvent therein is substantially removed;
- and
- elevating the temperature so that imidizing of the polyimide occurs.
A transducer structure, comprising:
- a transducer assembly having an apertured face;
- a pedestal tube mounted to said transducer assembly face so as to provide a fluid channel to said aperture;
- and
- a polyimide adhesive film between said pedestal tube and said transducer assembly, said adhesive film being less than about 0.3 mil in thickness.
Dependencies are inferred from the claim text.