Gas sensor package

Patent metadata

Field	Value
Publication number	US-9952171-B2
Application number	US-201514728218-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 6, 2014
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A gas sensor package comprises a gas sensor chip with a layer sensitive to a gas, and with a heater for heating the sensitive layer. Contact pads are provided for electrically contacting the gas sensor package and a die pad is provided for mounting the gas sensor chip to. Electrical connections connect the gas sensor chip and the contact pads. A molding compound at least partially encloses the gas sensor chip. An opening in the molding compound provides access to the sensitive layer of the gas sensor chip. One of the contact pads serves as a pin for supplying electrical current to the heater of the gas sensor chip.

First claim

The invention claimed is:

1. A gas sensor package, comprising
a gas sensor chip comprising a semiconductor substrate, a processing circuit integrated into the semiconductor substrate, a layer sensitive to a gas and connected to the processing circuit, and a heater for heating the sensitive layer,
contact pads for electrically contacting the gas sensor chip,
a die pad for mounting the gas sensor chip to,
electrical connections between the gas sensor chip ( 3 ) and the contact pads,
a molding compound at least partially enclosing the gas sensor chip, and
an opening in the molding compound providing access to the sensitive layer of the gas sensor chip,
wherein one of the contact pads serves as a pin for supplying electrical current to the heater of the gas sensor chip,
wherein another one of the contact pads serves as a supply pin for supplying power for operating the gas sensor chip except for the heater, and
wherein the processing circuit is configured to control the heater.

2. The gas sensor package of claim 1 ,
comprising a front side and a back side, wherein the opening is arranged in the front side, and wherein the contact pads are arranged at the back side.

3. The gas sensor package of claim 2 ,
wherein the contact pads and the die pad are exposed from the molding compound at the back side of the gas sensor package.

4. The gas sensor package according to claim 1 ,
wherein the gas sensor package has the shape of a cuboid, and
in particular wherein the opening in the molding compound has a circular footprint.

5. The gas sensor package of claim 4 ,
wherein the gas sensor package has a footprint of l×w mm 2 , and
wherein the length l of the footprint of the gas sensor package is lϵ[2.3, 2.6] mm, and the width w is wϵ[2.3, 2.6] mm.

6. The gas sensor package of claim 4 ,
wherein a diameter d of the opening is less than 2 mm,
and in particular wherein the diameter d of the opening is dϵ[1.4, 1.6] mm.

7. The gas sensor package according to claim 4 ,
wherein the opening is arranged centered in the front side of the gas sensor package.

8. The gas sensor package according to claim 1 ,
wherein the gas sensor chip comprises a front side and a back side,
wherein a recess is provided in the backside of the gas sensor chip,
wherein the sensitive layer is arranged at the front side of the gas sensor chip in a portion above the recess, and
wherein the gas sensor chip is mounted with its backside to the die pad thereby building a cavity defined by the recessed portion of the gas sensor chip and the die pad.

9. The gas sensor package of claim 8 ,
wherein the die pad comprises a hole for venting the cavity.

10. The gas sensor package according to claim 1 ,
wherein a third one of the contact pads serves as a ground pin.

11. The gas sensor package according to claim 1 ,
wherein a fourth one of the contact pads serves as a data pin for at least receiving measurement data from the gas sensor chip communicated according to a communication protocol, and
in particular wherein a fifth one of the contact pads serves as clock pin for a clock for operating the communication protocol.

12. The gas sensor package according to claim 1 ,
wherein a sixth one of the contact pads serves as a programmable pin for programming the gas sensor chip.

13. The gas sensor package according to claim 2 ,
wherein a third one of the contact pads serves as a ground pin,
wherein a fourth one of the contact pads serves as a data pin for at least receiving measurement data from the gas sensor chip communicated according to a communication protocol,
wherein a fifth one of the contact pads serves as clock pin for a clock for operating the communication protocol,
wherein a sixth one of the contact pads serves as a programmable pin for programming the gas sensor chip,
wherein the six contact pads are arranged in two rows by three at the backside of the gas sensor package.

14. The gas sensor package according to claim 13 ,
wherein the die pad is arranged between the two rows of three contact pads each, and
in particular wherein the die pad is of rectangular shape, and
in particular wherein the rectangular shape of the die pad is modified for encoding an orientation of the gas sensor package.

15. The gas sensor package according to claim 1 ,
wherein the contact pads are represented by individual electrically conducting platforms, and
wherein the electrical connections between the gas sensor chip and the contact pads comprise bond wires.

16. The gas sensor package according to claim 2 ,
wherein the front side and the back side of the gas sensor package are linked by side walls (SW), and
wherein one front end of each contact pad is exposed from the side walls.

17. The gas sensor package according to claim 2 ,
wherein the front side of the gas sensor package comprises at least one marking, and
in particular wherein the front side is of rectangular shape and wherein each marking is arranged in a corner of the front side.

18. The gas sensor package according to claim 2 ,
wherein the other contact pad serving as supply pin for supplying power for operating the gas sensor chip except for the heater and the contact pads serving as pin for operating the heater are arranged at different edges of the back side of the gas sensor package.

Assignees

• Sensirion Ag

Inventors

• Hunziker Werner
• Pustan David
• Braun Stephen

Classifications

• H10W74/111

  the semiconductor body being completely enclosed · CPC title

• G01N27/123

  for controlling the temperature (temperature control per se G05D23/00) · CPC title

• G01N27/128

  Microapparatus · CPC title

• G01N33/0009 Primary

  General constructional details of gas analysers, e.g. portable test equipment (devices for withdrawing samples in the gaseous state G01N1/22) · CPC title

• G01N27/26 Primary

  by investigating electrochemical variables; by using electrolysis or electrophoresis · CPC title