Placement of damage sensors in an air-temperature-managed equipment enclosure

Patent metadata

Field	Value
Publication number	US-10830809-B2
Application number	US-201816164079-A
Country	US
Kind code	B2
Filing date	Oct 18, 2018
Priority date	Oct 18, 2018
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A temperature-managed equipment enclosure, wherein the fans are configured to draw air from the environment, and wherein damage sensors are distributed in a non-uniform and/or targeted manner. In an example embodiment, most of the damage sensors may be placed within a relatively narrow zone downstream from the cooling fans. In some embodiments, a relatively large percentage of the damage sensors may be placed in the areas characterized by one or more of the following: (i) relatively high linear velocity of the airflow; (ii) turbulent airflow; and (iii) a certain range of angles of impingement of airflow on the equipment surfaces. Advantageously, the disclosed placement of damage sensors can be used to enhance the ability to detect environmentally induced equipment damage with high sensitivity and/or certainty.

First claim

What is claimed is:

1. An apparatus comprising:
a circuit board located in an enclosure for electrical equipment;
one or more fans configured to generate an airflow along a major surface of the circuit board by drawing external air into the enclosure, each of the one or more fans having an exhaust along an edge of the circuit board; and
a plurality of resistive sensors supported on the circuit board, the resistive sensors being on average closer to the exhaust than most of the circuit board, each of the resistive sensors having a respective electrical resistance configured to change in response to damage caused by material carried in the airflow.

2. The apparatus of claim 1 , wherein the exhaust is oriented to cause the airflow to have a substantial velocity component parallel to the major surface of the circuit board.

3. The apparatus of claim 1 , wherein some of the resistive sensors of the plurality are located adjacent to the edge of the circuit board.

4. The apparatus of claim 1 , wherein said some of the resistive sensors include at least 80% of the resistive sensors of the plurality.

5. The apparatus of claim 1 , wherein the plurality of resistive sensors are located in a region susceptible to receipt of a turbulent part of the airflow generated by the one or more fans.

6. The apparatus of claim 1 , wherein the edge of the circuit board is located next to a fan tray, the one or more fans being in the fan tray.

7. The apparatus of claim 6 , wherein the edge is substantially parallel to a long side of the fan tray.

8. The apparatus of claim 1 , wherein most of the resistive sensors of the plurality are in local areas susceptible to accumulation per unit surface area of particulate matter capable of settling out of the airflow that is greater than average accumulation per unit surface area of said particulate matter on the circuit board.

9. The apparatus of claim 8 , where the local areas are susceptible to accumulation per unit area of said particulate matter that is greater by at least a factor of ten than said average accumulation.

10. The apparatus of claim 1 , wherein the one or more fans are connected to draw said external air from an exterior of a building or structure in which the enclosure is located.

11. The apparatus of claim 1 , wherein the enclosure is configured to be mounted on a shelf for electronic equipment.

12. The apparatus of claim 1 , wherein the enclosure is a substantially closed enclosure.

13. The apparatus of claim 1 , wherein most or all of the resistive sensors of the plurality are located between 1 cm (centimeter) and 4 cm from the edge.

14. The apparatus of claim 1 , wherein the circuit board is a part of a circuit pack that is rack-mounted in the enclosure in a movable manner.

15. The apparatus of claim 1 , wherein the plurality of resistive sensors comprises a first sensor having an electrical resistance configured to increase in response to the first sensor being damaged by the material carried in the airflow.

16. The apparatus of claim 15 wherein the plurality of resistive sensors comprises a second sensor having an electrical resistance configured to decrease in response to the second sensor being damaged by the material carried in the airflow.

17. The apparatus of claim 1 wherein the plurality of resistive sensors comprises a first sensor having an electrical resistance configured to decrease in response to the first sensor being damaged by the material carried in the airflow.

18. An apparatus comprising:
a circuit board located in an enclosure;
one or more fans configured to generate an airflow along a major surface of the circuit board by drawing external air into the enclosure, each of the one or more fans having an exhaust along an edge of the circuit board; and
a plurality of resistive sensors located in a local area susceptible to a deposition per unit area of particulate matter capable of settling out of the airflow greater than an average deposition per unit area of said particulate matter on the circuit board.

19. The apparatus of claim 18 , wherein the deposition per unit area of said particulate matter on said local area is greater by a factor of ten or more than the average deposition per unit area of said particulate matter on the circuit board.

20. The apparatus of claim 18 , wherein the exhaust is oriented to cause the airflow to be incident on the plurality of resistive sensors and have a major component parallel to the major surface of the circuit board.

21. The apparatus of claim 18 , wherein most of the resistive sensors of the plurality are located near the edge of the circuit board.

22. The apparatus of claim 18 , wherein the plurality of resistive sensors are located in a region susceptible to receipt of a turbulent part of the airflow generated by the one of more fans.

Assignees

• Nokia Technologies Oy

Inventors

• Xu Chen

Classifications

• G01R31/2812 Primary

  Checking for open circuits or shorts, e.g. solder bridges; Testing conductivity, resistivity or impedance (of connections G01R31/66) · CPC title

• G01N27/041 Primary

  of a solid body · CPC title

• G01R31/2856

  Internal circuit aspects, e.g. built-in test features; Test chips; Measuring material aspects, e.g. electro migration [EM] · CPC title

• G01R31/2836

  Fault-finding or characterising (G01R31/2822 - G01R31/2831 take precedence) · CPC title

• G01N17/04 Primary

  Corrosion probes · CPC title