Method of making a molded thermometer probe component

• US 9,453,768 B2
• Filed: 07/01/2013
• Issued: 09/27/2016
• Est. Priority Date: 12/31/2007
• Status: Active Grant

• Current Assignee: Cardinal Health Ireland Unlimited Company (Cardinal Health, Inc.)
• Original Assignee: Covidien AG (Medtronic Plc)
• Inventors: Harr, James, Gierer, Joseph T.
• Primary Examiner(s): Pham, Thiem
• Application Number:
  US13/932,199
• Publication Number:
  US 20130326872A1
• Time in Patent Office: 1,184 Days
• Field of Search: 298/48, 298/25, 298/32, 298/41, 298/54, 298/74, 374/163, 374/170, 374/185, 374/208, 374/209, 374/E7.028, 374/E13.002
• US Class Current: 1/1
• CPC Class Codes: G01K 1/14 Supports; Fastening devices; Arrangements for mounting thermometers in particular locations
• CPC Class Codes: G01K 13/20 Clinical contact thermometers for use with humans or animals
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.

Abstract

A medical measurement device, such as an electronic thermometer, having a probe. The probe includes a molded plastic substrate having a conductive circuit pattern formed directly on its surface. The circuit pattern extends at least from a first end margin of the molded plastic substrate to a second end margin opposite the first. The device also includes a sensor mounted on the molded plastic substrate for detecting a physiological parameter, such as temperature. The sensor is positioned on the molded plastic substrate at the first end margin by at least one positioning element integrally formed in the substrate. The conductive circuit pattern provides an electrical connection between the sensor and a processor.

Claims

1. A method of making a sensor probe for an electronic thermometer, said method comprising:

injecting thermoplastic resin into one or more cavities to form a plastic substrate, at least one of said cavities defining at least one positioning element integrally formed in the plastic substrate at a first end margin thereof;

forming a conductive circuit pattern directly on a surface of the plastic substrate from the first end margin of the plastic substrate to an opposite second end margin of the plastic substrate;

positioning a temperature sensor at the first end margin of the plastic substrate relative to the at least one positioning element; and

mounting the positioned temperature sensor on the plastic substrate, wherein the conductive circuit pattern provides an electrical connection between the temperature sensor and a processor of the electronic thermometer for generating a temperature measurement as a function of a temperature detected by the temperature sensor.

2. The method of claim 1, wherein the probe has a tip and a shaft, said probe shaft including at least the second end margin of the plastic substrate and the conductive circuit pattern formed thereon, and further comprising:

introducing at least a portion of the probe shaft into an overmold cavity, wherein a void is formed between the probe shaft and the overmold cavity; and

injecting thermoplastic resin into the overmold cavity, wherein said thermoplastic resin is bonded to at least a portion of a surface of the probe shaft to form a casing therefor.

3. The method of claim 2, wherein the temperature sensor is mounted on the plastic substrate after forming the casing for the at least a portion of the probe shaft.

4. The method of claim 1, wherein the surface of the plastic substrate includes at least one plateable portion and at least one non-plateable portion, and wherein forming the conductive circuit pattern comprises applying a conductive material to the plateable portion of the surface of the plastic substrate.

5. The method of claim 4, wherein injecting thermoplastic resin into one or more cavities to form the plastic substrate comprises

injecting a plateable thermoplastic resin into a first cavity to form a preliminary plastic substrate having plateable surfaces;

introducing at least a portion of the preliminary plastic substrate into a second cavity, wherein one or more voids are formed between surfaces of the preliminary plastic substrate and the second cavity;

injecting a non-plateable thermoplastic resin into the second cavity to form the plastic substrate, said non-plateable thermoplastic resin bonding to the plateable surfaces of the preliminary plastic substrate in a pattern corresponding to the voids.

6. The method of claim 5, wherein the first cavity is a mold having a first shape and the second cavity is said mold reconfigured to have a second shape.

7. The method of claim 4, wherein injecting thermoplastic resin into one or more cavities to form the plastic substrate comprises

injecting a non-plateable thermoplastic resin into a first cavity to form a preliminary plastic substrate having non-plateable surfaces;

introducing at least a portion of the preliminary plastic substrate into a second cavity, wherein one or more voids are formed between surfaces of the preliminary plastic substrate and the second cavity; and

injecting a plateable thermoplastic resin into the second cavity to form the plastic substrate, said plateable thermoplastic resin bonding to the non-plateable surfaces of the preliminary plastic substrate in a pattern corresponding to the voids.

8. The method of claim 7, wherein the first cavity is a mold having a first shape and the second cavity is said mold reconfigured to have a second shape.

9. The method of claim 1, wherein forming the conductive circuit pattern comprises applying at least one conductive trace to the plastic substrate using one or more of the following techniques:

electroplating, hot-stamping, capture processing, transfer processing, laser-direct structuring, laser subtractive structuring, and photoimaging.

10. The method of claim 1, wherein the at least one positioning element comprises a recess formed in the plastic substrate, said recess being sized and shaped for receiving the temperature sensor therein, and wherein mounting the temperature sensor comprises locating the recess at the first end margin of the plastic substrate for receiving the temperature sensor and attaching, via an electrically conductive adhesive, the temperature sensor to a receiving surface of the recess.

11. The method of claim 1, wherein the at least one positioning element comprises a protrusion formed in the plastic substrate, said protrusion being sized and shaped for engaging the temperature sensor therein, and wherein mounting the temperature sensor comprises locating the protrusion at the first end margin of the plastic substrate for receiving the temperature sensor and attaching, via an electrically conductive adhesive, the temperature sensor to a receiving surface of the protrusion.

12. The method of claim 1, wherein the one or more cavities define a first positioning element and a second positioning element integrally formed in the plastic substrate.

13. The method of claim 12, further comprising:

positioning a heating element at the first end margin of the plastic substrate relative to the second positioning element; and

mounting the positioned heating element on the plastic substrate.

14. The method of claim 13, further comprising:

receiving an isolator by the first end margin of the plastic substrate, said isolator comprising a thermally insulating material for thermally isolating the first end margin of the plastic substrate from a remainder of the plastic substrate including the second end margin; and

receiving a separator by the first end margin of the plastic substrate, wherein said separator is in thermal contact with the temperature sensor and positioned between the temperature sensor and the isolator.

15. The method of claim 13, wherein the first positioning element is sized and shaped for engaging the temperature sensor, and wherein mounting the temperature sensor comprises locating the first positioning element at the first end margin of the plastic substrate for receiving the temperature sensor and attaching, via an electrically conductive adhesive, the temperature sensor to a receiving surface of the first positioning element.

16. The method of claim 13, wherein the second positioning element is sized and shaped for engaging the heating element, and wherein mounting the heating element comprises locating the second positioning element at the first end margin of the plastic substrate for receiving the heating element and attaching, via an electrically conductive adhesive, the heating element to a receiving surface of the second positioning element.

17. The method of claim 1, wherein the probe has a probe tip and a probe shaft, said probe shaft including an electrical conductor electrically conducted both to the conductive circuit pattern formed on the plastic substrate at the second end margin thereof and to the processor for electrically connecting the temperature sensor to the processor.

18. The method of claim 17, further comprising encasing at least a portion of the plastic substrate at the second end margin with a probe shaft cover while exposing at least a portion of the plastic substrate at the first end margin.

19. The method of claim 18, wherein the probe shaft cover comprises a molded plastic layer.

20. The method of claim 17, further comprising encasing at least a portion of the plastic substrate at the first end margin and the temperature sensor mounted thereon with a probe tip cover, said probe tip cover comprising a thermally conductive material, wherein said probe tip cover is in thermal contact with the temperature sensor when encasing the temperature sensor.