Method of producing an integrated reference pressure sensor element

• US 6,735,845 B2
• Filed: 08/20/1999
• Issued: 05/18/2004
• Est. Priority Date: 02/20/1997
• Status: Expired due to Term

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Jonsson, Staffan
• Primary Examiner(s): Tugbang, A. Dexter
• Application Number:
  US09/377,833
• Publication Number:
  US 20030110865A1
• Time in Patent Office: 1,733 Days
• Field of Search: 295/95, 296/11, 296/13, 29/254.1, 295/94, 737/15, 737/18, 737/24, 445/31, 445/41, 445/55, 252/181.1, 252/181.2, 252/181.3, 219/604, 438/402, 438/471, 438/FOR.144
• US Class Current: 29/595
• CPC Class Codes: G01L 9/0044 Constructional details of non-semiconductive diaphragms
• CPC Class Codes: G01L 9/0072 using variations in capacitance
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass
• CPC Class Codes: Y10T 29/43 Electric condenser making
• CPC Class Codes: Y10T 29/49007 Indicating transducer
• CPC Class Codes: Y10T 29/49083 Heater type

Abstract

A method of manufacturing a pressure sensor house assembly which contains a reference cavity, in which a vacuum exists, and a getter capable of being thermally activated. The getter is activated by directly contacting the getter with an exterior heated body, conducting heat from the exterior heated body, maintaining the exterior heated body in direct contact with the getter for a predetermined period of time, and removing the exterior heated body.

Claims

1. A method of producing a pressure sensor comprising a pressure sensor house assembly which contains a reference cavity, in which a vacuum exists, and furthermore comprising a getter capable of being thermally activated, the method comprising activating the getter by directly contacting the getter with an exterior heated body that is heated via a heat source, conducting heat from the exterior heated body, maintaining the exterior heated body in direct contact with the getter for a predetermined period of time, and removing the heat source and sealing the pressure house assembly with the exterior heated body,

wherein the method further comprises:

producing the pressure sensor house of substantially ceramic material having the reference cavity arranged therein and a single closing channel from a main portion of the reference cavity to a mouth at the outside,

pumping air out of a room containing the pressure sensor house, so that a vacuum is obtained therein and in the reference cavity,

arranging a glass joint material on a closing lid, the glass joint material being capable of being thermally activated, the arranging step being practiced by arranging the joint material in a dotted pattern on the closing lid to allow gases that come into contact with the closing lid to be let out via a slot formed at a surface of the joint material,

heating the closing lid and placing the closing lid over the mouth of the closing channel, and

allowing the closing lid to cool.

2. A method of producing a pressure sensor comprising a pressure sensor house assembly containing a reference cavity, in which a vacuum exists, the method comprising:

producing a pressure sensor house including the reference cavity, which comprises an opening or a channel from a main portion of the cavity to outside the sensor house,

placing a getter capable of being thermally activated so that at least a portion of a surface of the getter forms a wall surface of the reference cavity,

attaching a closing lid to a body at a distance from the pressure sensor house so that gas can freely pass between the body comprising the lid attached thereto and the pressure sensor house,

increasing a temperature of the body and then of the closing lid to a temperature at which the getter is activated,

moving the body to such a position that the closing lid is applied tightly to the pressure sensor house and is attached in this position to the pressure sensor house and that then at least one of the body and the lid conducts heat to the getter, and

releasing the body from the closing lid.

3. The method according to claim 2, wherein before increasing the temperature of the body, the method comprising placing the pressure sensor house in a room and pumping air out of the room to become substantially a vacuum.

4. The method according to claim 2, wherein the step of increasing the temperature of the body is practiced by increasing the temperature of the body to a temperature at which the getter starts to be activated to a substantial extent and by maintaining the body at this temperature during a time period that effects a substantial activation of the getter.

5. The method according to claim 4, further comprising, prior to moving the body to the position in which the closing lid is applied tightly to the house, the step of increasing the temperature of the body further during a short period of time to produce a final activation of the getter.

6. The method according to claim 2, further comprising applying a sealing adhesive which is capable of being thermally activated to the closing lid in order to seal and attach the closing lid to the pressure sensor house.

7. A method of producing a pressure sensor including a pressure sensor house assembly comprising a reference cavity, in which a vacuum exists, the method comprising:

producing a pressure sensor house of substantially ceramic material having the reference cavity arranged therein and a single channel extending from a main portion of the reference cavity up to a mouth at an outside of the pressure sensor house,

pumping air out of a room containing the pressure sensor house so that a vacuum is obtained therein and in the reference cavity,

heating a closing lid including a joint material, which is arranged thereon and can be thermally activated, and then placing the closing lid on top of the mouth of the channel, and

allowing the closing lid to cool,

wherein, prior to the heating step, the method further comprises a step of arranging the joint material in a dotted pattern on the closing lid thereby allowing gases released in the heating step in the engagement of the closing lid with the pressure sensor house to be let out from a slot formed at a surface of the joint material.