Browse Prior Art Database

On Chip Temperature Sensor

IP.com Disclosure Number: IPCOM000105616D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 4 page(s) / 118K

Publishing Venue

IBM

Related People

Aubertine, ME: AUTHOR [+5]

Abstract

Monitoring the temperature of a chip has always been vital to any company with multi-chip package design. A method for measuring the temperature of chips on a modules is discussed in this paper. On Chip Thermal Sensors (OCTS) device is a diode that will be present on every chip. OCTS pins are automatically cross referenced together to the package I/Os forming a grid pattern based on rules. The wired OCTS nets will be automatically checked for any potentially incorrect connections, possibly injected by manual hook-up. The OCTS design is hardware independent, hence, flexible to future technology changes.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

On Chip Temperature Sensor

      Monitoring the temperature of a chip has always been vital to
any company with multi-chip package design.  A method for measuring
the temperature of chips on a modules is discussed in this paper.  On
Chip Thermal Sensors (OCTS) device is a diode that will be present on
every chip.  OCTS pins are automatically cross referenced together to
the package I/Os forming a grid pattern based on rules.  The wired
OCTS nets will be automatically checked for any potentially incorrect
connections, possibly injected by manual hook-up.  The OCTS design is
hardware independent, hence, flexible to future technology changes.

      Monitoring the temperature of a chip is done in order to keep
the chips within the specified operating temperature range.
Exceeding this range will result in degraded performance as well as
reduced reliability.  (Overheating a component can result in
premature failure) The ability to measure the temperature of the
chips on a module will allow identification of overheated chips and
hence modification of the design.  In previous designs there was no
method of evaluating the temperature of ALL the chips on a module.
Chip temperature was measured on a sample basis, resulting in
incomplete and potentially misleading data.  Chips not included in
the sample could overheat resulting in component damage which would
not be detected until significant numbers of failures were reported.
This method was technology-dependent and lacked flexibility.

      A full sampling scheme would enable detection of overheated
chips and a timely modification of the design to bring the chips back
within the specified operating range.  A new method was developed to
apply temperature sensors, to connect the sensor nets to all chips to
be able to monitor all chips, and to model these connections in
software.  Software modeling is needed so that the connections could
be made and checked automatically.

      OCTS is used to measure the temperature of the chips on a
module.  The OCTS diode that is present at every populated chip
location can be accessed to sense the junction temperature and
therefore avoid overheating of the chips.  The OCTS circuit has
multiple uses during both development and manufacturing phases.
During system development a temperature sensing device on every chip
enables detection of overheated chips.  This will set an early
warning flag that allows timely modification of the design to bring
the chips back within the specified operating range.  During system
bring-up OCTS will be used to conduct thermal evaluations.  OCTS can
be used at other stages also, including burn-in.

      OCTS is a group of transistors wired as a diode. ...