Tamper-proof electronic packages with two-phase dielectric fluid

Patent metadata

Field	Value
Publication number	US-9904811-B2
Application number	US-201615139503-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	Apr 27, 2016
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Tamper-proof electronic packages and fabrication methods are provided including an enclosure enclosing, at least in part, at least one electronic component within a secure volume, a two-phase dielectric fluid within the secure volume, and a tamper-respondent detector. The tamper-respondent detector monitors, at least in part, temperature and pressure of the two-phase dielectric fluid. In operation, the two-phase dielectric fluid deviates from an established saturation line of the two-phase dielectric fluid within the secure volume with an intrusion event into the secure volume, and the tamper-respondent detector detects, from the monitoring of the temperature and pressure of the two-phase dielectric fluid, the deviation from the established saturation line, and thereby occurrence of the intrusion event.

First claim

What is claimed is:

1. A tamper-proof electronic package comprising:
an enclosure to enclose, at least in part, at least one electronic component within a secure volume;
a two-phase dielectric fluid within the secure volume, the two-phase dielectric fluid comprising liquid dielectric fluid and vapor dielectric fluid within the secure volume, and the two-phase dielectric fluid being at an established saturation line of the two-phase dielectric fluid within the secure volume; and
a tamper-respondent detector to monitor, at least in part, temperature and pressure of the two-phase dielectric fluid and determine therefrom a current pressure temperature relationship, wherein in operation, the current pressure temperature relationship of the two-phase dielectric fluid deviates from the established saturation line of the two-phase dielectric fluid within the secure volume with an intrusion event into the secure volume, and the tamper-respondent detector detects, from the monitoring of the temperature and pressure of the two-phase dielectric fluid and the determining of the current pressure temperature relationship, deviation from the established saturation line, and thereby the intrusion event.

2. The tamper-proof electronic package of claim 1 , wherein the at least one electronic component is immersed within the liquid dielectric fluid within the secure volume and, in operation, the two-phase dielectric fluid boils at the at least one electronic component and condenses at an inner condensing surface of the tamper-proof electronic package within a vapor region of the secure volume.

3. The tamper-proof electronic package of claim 2 , further comprising at least one tamper-respondent sensor coupled to an inner surface of the enclosure, the at least one tamper-respondent sensor comprising circuit lines defining one or more tamper-detect networks, and wherein the inner condensing surface comprises a surface of the at least one tamper-respondent sensor, and the tamper-respondent detector further monitors the one or more tamper-respondent networks for the intrusion event.

4. The tamper-proof electronic package of claim 3 , further comprising:
a multilayer circuit board, the enclosure being coupled to the multilayer circuit board, and together, the enclosure and the multilayer circuit board enclosing the at least one electronic component; and
a tamper-respondent sensor embedded within the multilayer circuit board, the embedded tamper-respondent sensor defining, at least in part, the secure volume, and the embedded tamper-respondent sensor comprising one or more additional tamper-detect networks embedded within the multilayer circuit board.

5. The tamper-proof electronic package of claim 2 , further comprising a thermally conductive condenser with a plurality of thermally conductive fins disposed within the vapor region of the secure volume, the inner condensing surface being a surface of the thermally conductive condenser.

6. The tamper-proof electronic package of claim 5 , further comprising at least one tamper-respondent sensor coupled to an inner surface of the enclosure, the at least one tamper-respondent sensor comprising circuit lines defining one or more tamper detect networks, and wherein the at least one tamper-respondent sensor covers an inner main surface of the enclosure, and the thermally conductive condenser overlies, at least in part, the at least one tamper-respondent sensor, the at least one tamper-respondent sensor being disposed, at least in part, between the enclosure and the thermally conductive condenser.

7. The tamper-proof electronic package of claim 1 , further comprising an external condenser, the external condenser being coupled in fluid communication with the secure volume via a vapor fluid tube and a liquid fluid tube, wherein dielectric fluid vapor passes from the secure volume to the external condenser through the vapor fluid tube, condenses within the external condenser, and is returned to the secure volume via the liquid fluid tube as liquid dielectric fluid.

8. The tamper-proof electronic package of claim 1 , wherein the detecting by the tamper-respondent detector comprises:
determining a saturation line residual using the monitored temperature and pressure of the two-phase dielectric fluid within the secure volume;
determining whether the saturation line residual exceeds a predefined saturation line residual threshold; and
the tamper-respondent detector detecting occurrence of the intrusion event when the determined saturation line residual exceeds the predefined saturation line residual threshold.

9. The tamper-proof electronic package of claim 8 , wherein the tamper-respondent detector further monitors ambient temperature external to the enclosure, and detects occurrence of the intrusion event when the monitored ambient temperature equals or exceeds the monitored temperature of the two-phase dielectric fluid within the secure volume adjusted by a predefined tolerance value or percentage.

10. A tamper-proof electronic package comprising:
at least one electronic component;
an enclosure enclosing, at least in part, the at least one electronic component within a secure volume;
a two-phase dielectric fluid within the secure volume, the two-phase dielectric fluid comprising liquid dielectric fluid and vapor dielectric fluid within the secure volume, and the two-phase dielectric fluid being at an established saturation line of the two-phase dielectric fluid within the secure volume; and
a tamper-respondent detector to monitor, at least in part, temperature and pressure of the two-phase dielectric fluid and determine therefrom a current pressure temperature relationship, wherein in operation, the current pressure temperature relationship of the two-phase dielectric fluid deviates from the established saturation line of the two-phase dielectric fluid within the secure volume with an intrusion event into the secure volume, and the tamper-respondent detector detects, from the monitoring of the temperature and pressure of the two-phase dielectric fluid and the determining of the current pressure temperature relationship, deviation from the established saturation line, and thereby the intrusion event.

11. The tamper-proof electronic package of claim 10 , wherein the at least one electronic component is immersed within the liquid dielectric fluid within the secure volume and, in operation, the two-phase dielectric fluid boils at the at least one electronic component and condenses at an inner condensing surface of the tamper-proof electronic package within a vapor region of the secure volume.

12. The tamper-proof electronic package of claim 11 , further comprising at least one tamper-respondent sensor coupled to an inner surface of the enclosure, the at least one tamper-respondent sensor comprising circuit lines defining one or more tamper-detect networks, and wherein the inner condensing surface comprises a surface of the at least one tamper-respondent sensor, and the tamper-respondent detector further monitors the one or more tamper-respondent networks for the intrusion event.

13. The tamper-proof electronic package of claim 12 , further comprising:
a multilayer circuit board, the enclosure being coupled to the multilayer circuit board, and together, the enclosure and the multilayer circuit board enclosing the at least one electronic component; and
a tamper-respondent sensor embedded within the multilayer circuit board, the tamper-respondent sensor defining, at least in part, the secure volume, and the tamper-respondent sensor comprising one or more additional tamper-detect networks embedded within the multilayer circuit board.

Assignees

• IBM

Inventors

• Campbell Levi A
• David Milnes P
• Demetriou Dustin W
• Ellsworth Jr Michael J

Classifications

• H05K7/203

  by immersion · CPC title

• H05K5/0208

  Interlock mechanisms; Means for avoiding unauthorised use or function, e.g. tamperproof · CPC title

• H05K2203/0776

  Uses of liquids not otherwise provided for in H05K2203/0759 - H05K2203/0773 · CPC title

• H05K1/0272

  Adaptations for fluid transport, e.g. channels, holes · CPC title

• H05K1/0298

  Multilayer circuits · CPC title