Browse Prior Art Database

Method for an embedded resistance temperature detector on integrated heat spreader

IP.com Disclosure Number: IPCOM000006571D
Publication Date: 2002-Jan-15
Document File: 6 page(s) / 57K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for an embedded resistance temperature detector (RTD) on an integrated heat spreader (IHS). Benefits include improved test time, improved results, and improved repeatability.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Method for an embedded resistance temperature detector on integrated heat spreader

Disclosed is a method for an embedded resistance temperature detector (RTD) on an integrated heat spreader (IHS). Benefits include improved test time, improved results, and improved repeatability.

Background

      IHS surface temperature is conventionally measured by attaching thermocouples to an exact spot on the IHS (see Figure 1) either by drilling through the heat sink from the top in the 90-degree attachment method (see Figure 2), or by making a groove on the IHS in the 0-degree attachment method (see Figure 3). In either case, modifications to the heat sink or the IHS are required. The process takes an average of 2 hours, including cure time, and more if multiple thermocouples are required. The process is not repeatable between different users. Each thermocouple can cost from $10 to $80 each, depending on the accuracy required.

Description

              The disclosed method embeds one or more RTDs on the surface of the IHS. The embedded RTDs are used to accurately measure the IHS’s surface temperature.

      The disclosed method results from the investigation into improvements required for conventional thermal resistance metrology (TRM) to be capable for future packaging technologies. The investigation has identified IHS surface temperature measurement using thermocouples, the conventional method, as the largest contributor to the measurement system variation (Sms). It must be eliminated for TRM to be capable.

      The disclosed method is comprised of three key components: insulating layers, an RTD elements and traces layer, and an output tab (see Figure 4).

      The purpose of the insulating layers is to insulate the RTD elements and traces layer from the surrounding layers, so accurate resistance values of the RTD elements can be measured. There are two insulating layers. One is located in between the copper IHS and the RTD-traces layer. The second insulates the RTD-traces layer from the heat sink. Each insulating layer is approximately 1-micron thick and could be made of oxide or some other yet-to-be-identified material, which can be deposited through chemical vapor deposition (CVD) or similar techniques.

      The RTD elements and traces layer is comprised of the RTD elements, which are calibrated 4-point Kelvin structures. Their measured resistances can be converted to temperature using calibration curves. Each RTD has four traces ending at the output tab on the side edge of the IHS.

      The output tab can be soldered to the lead from the external source equipment and voltmeter (see Figure 3). This equipment can alternatively be wire bonded directly to the substrate of the package and then routed through the package pins.

Advantages

              The disclosed method presents several advantages over the conven...