R Intel® Pentium® 4 Processor on 90 nm Process Thermal and Mechanical Design Guidelines Design Guide February 2004 Document Number: 300564-001
R INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL® PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT.
R Contents 1 Introduction ......................................................................................................................... 9 1.1 1.2 1.3 2 Mechanical Requirements ................................................................................................ 13 2.1 2.2 3 Overview............................................................................................................... 10 References ..........................................................................
R 3.6 3.7 3.8 4 Acoustic Fan Speed Control................................................................................. 32 3.6.1 Example Implementation ...................................................................... 33 3.6.2 Graphs of Fan Response...................................................................... 33 Reading the On-Die Thermal Diode Interface...................................................... 34 Impacts to Accuracy .........................................................
R Thermal Test Vehicle (TTV) Information.............................................................. 75 Introduction ........................................................................................... 75 TTV Preparation.................................................................................... 75 TTV Connections for Power-Up............................................................ 76 Recommended DC Power Supply Ratings...........................................
R Figures Figure 1. Processor Case Temperature Measurement Location ..................................... 15 Figure 2. Heatsink Exhaust Providing Platform Subsystem Cooling ................................ 18 Figure 3. Processor Thermal Characterization Parameter Relationships ........................ 20 Figure 4. Locations for Measuring Local Ambient Temperature, Active Heatsink (not to scale) .................................................................................................................
R Tables Table 1. Thermal Diode Interface ..................................................................................... 34 Table 2. Reference Heatsink Performance Targets ......................................................... 37 Table 3. Temperature Cycling Parameters....................................................................... 41 Table 4. Intel® Pentium® 4 Processor on 90 nm Process Reference Thermal Solution Performance ................................................................
R Revision History Revision Number -001 8 Description • Initial Release Date February 2004 Intel® Pentium® 4 on 90 nm Process Thermal Design Guide
Introduction R 1 Introduction The objective of thermal management is to ensure that the temperatures of all components in a system are maintained within their functional temperature range. Within this temperature range, a component, and in particular its electrical circuits, is expected to meet its specified performance. Operation outside the functional temperature range can degrade system performance, cause logic errors or cause component and/or system damage.
Introduction R 1.1 Overview As the complexities of today’s microprocessors increase, the power dissipation requirements become more exacting. Care must be taken to ensure that the additional power is properly dissipated. Heat can be dissipated using passive heatsinks, fans, and/or active cooling devices. Incorporating ducted airflow solutions into the system thermal design can yield additional margin. The Pentium 4 processor on 90 nm process integrates thermal management logic onto the processor silicon.
Introduction R 1.2 References Material and concepts available in the following documents may be beneficial when reading this document. 1 Document ® Location ® Intel Pentium 4 Processor on 90 nm Process Datasheet ® Intel 865G/865GV/865PE/865P Chipset Design Guide ® http://developer.intel.com/desig n/pentium4/datashts/300561.ht m http://developer.intel.com/desig n/chipsets/designex/252518.ht m ® http://www.intel.com/design/chi psets/datashts/252514.
Introduction R Term Description ΨSA Sink-to-ambient thermal characterization parameter. A measure of heatsink thermal performance using total package power. Defined as (TS – TA) / Total Package Power. ΘCA Case-to-ambient thermal resistance (theta). Defined as (TC – TA) / Power dissipated from case to ambient. ΘCS Case-to-sink thermal resistance. Defined as (TC – TS) / Power dissipated from case to sink. ΘSA Sink-to-ambient thermal resistance.
Mechanical Requirements R 2 Mechanical Requirements 2.1 Processor Package The Pentium 4 processor on 90 nm process is packaged using Flip-Chip Micro Pin Grid Array 4 (FC-mPGA4) package technology. Refer to the Intel® Pentium® 4 Processor on 90 nm Process Datasheet for detailed mechanical specifications. The package includes an integrated heat spreader (IHS).
Mechanical Requirements R 2.2 Heatsink Attach There are no features on the mPGA478 socket to directly attach a heatsink: a mechanism must be designed to support the heatsink. In addition to holding the heatsink in place on top of the IHS, this mechanism plays a significant role in the robustness of the system in which it is implemented, in particular: • Ensuring thermal performance of the thermal interface material (TIM) applied between the IHS and the heatsink.
Thermal Requirements R 3 Thermal Requirements 3.1 Processor Case Temperature and Power Dissipation Refer to the Intel® Pentium® 4 Processor on 90 nm Process Datasheet for processor thermal specifications. Thermal specifications for the Pentium 4 processor on 90 nm process is the thermal profile. The thermal profile defines maximum case temperature as a function of power dissipated. The maximum case temperature for the maximum thermal design power (TDP) is the end point of the thermal profile.
Thermal Requirements R 3.2 Intel® Pentium® 4 Processor on 90 nm Process Thermal Solution Design Considerations 3.2.1 Heatsink Solutions 3.2.1.1 Heatsink Design Considerations To remove the heat from the processor, three basic parameters should be considered: • The area of the surface on which the heat transfer takes place. Without any enhancements, this is the surface of the processor package IHS. One method used to improve thermal performance is by attaching a heatsink to the IHS.
Thermal Requirements R 3.2.1.2 Thermal Interface Material Thermal interface material application between the processor IHS and the heatsink base is generally required to improve thermal conduction from the IHS to the heatsink. Many thermal interface materials can be pre-applied to the heatsink base prior to shipment from the heatsink supplier and allow direct heatsink attach, without the need for a separate thermal interface material dispense or attach process in the final assembly factory.
Thermal Requirements R to TDP instead of maximum power. Thermal Monitor can protect the processor in rare excursions of workload above TDP. Implementation options and recommendations are described in Section 3.4. 3.2.2.3 Omni Directional Airflow Intel recommends that the heatsink exhaust air in all directions parallel to the motherboard, thus, allowing airflow in the direction of the memory, chipset, and voltage regulator components.
Thermal Requirements R The case-to-local ambient thermal characterization parameter value (ΨCA) is used as a measure of the thermal performance of the overall thermal solution that is attached to the processor package.
Thermal Requirements R Figure 3. Processor Thermal Characterization Parameter Relationships TA ΨSA HEATSINK TS TIM PROCESSOR TC IHS ΨCA ΨCS SOCKET 3.2.3.1 Example The cooling performance, ΨCA, is then defined using the principle of thermal characterization parameter described above: • Define a target case temperature TC-MAX,F and corresponding thermal design power TDPF at a target frequency, F, given in the processor datasheet. • Define a target local ambient temperature at the processor, TA.
Thermal Requirements R 3.3 Thermal Metrology for the Intel® Pentium® 4 Processor on 90 nm Process 3.3.1 Processor Heatsink Performance Assessment This section discusses guidelines for testing thermal solutions, including measuring processor temperatures. In all cases, the thermal engineer must measure power dissipation and temperature to validate a thermal solution. Thermal performance of a heatsink should be assessed using a thermal test vehicle (TTV) provided by Intel.
Thermal Requirements R used, it may be useful to add a thermocouple taped to the barrier above the location of the temperature sensor used by the fan to check its speed setting against air temperature. When measuring TA in a chassis with a live motherboard, add-in cards, and other system components, it is likely that the TA measurements will reveal a highly non-uniform temperature distribution across the inlet fan section.
Thermal Requirements R Figure 5. Locations for Measuring Local Ambient Temperature, Passive Heatsink (not to scale) 3.3.3 Processor Case Temperature Measurement Guidelines To ensure functionality and reliability, the Pentium 4 processor on 90 nm process is specified for proper operation when TC is maintained at or below the thermal profile as listed in the Intel® Pentium® 4 Processor on 90 nm Process Datasheet. The measurement location for TC is the geometric center of the IHS.
Thermal Requirements R 3.4 Thermal Management Logic and Thermal Monitor Feature 3.4.1 Processor Power Dissipation An increase in processor operating frequency not only increases system performance, but also increases the processor power dissipation. The relationship between frequency and power is generalized in the following equation: P = CV2F (where P = power, C = capacitance, V = voltage, F = frequency).
Thermal Requirements R be determined. The reference current source corresponds to the diode current when at the maximum permissible processor operating temperature. The temperature at which PROCHOT# goes active is individually calibrated during manufacturing. The power dissipation of each processor affects the set point temperature. The temperature where PROCHOT# goes active is roughly parallel to the thermal profile.
Thermal Requirements R Figure 7. Concept for Clocks under Thermal Monitor Control PROCHOT# Normal clock Internal clock Duty cycle control Resultant internal clock 3.4.3 Bi-Directional PROCHOT# The Pentium 4 processor on 90 nm process implements a bi-directional PROCHOT# capability to allow system designs to protect various components from over-temperature situations.
Thermal Requirements R enabled, processor power consumption will be reduced within a few hundred clock cycles after the thermal sensor detects a high temperature (i.e., PROCHOT# assertion). The thermal control circuit and PROCHOT# transition to inactive once the temperature has been reduced below the thermal trip point, although a small time-based hysteresis has been included to prevent multiple PROCHOT# transitions around the trip point.
Thermal Requirements R 3.4.6 System Considerations The Thermal Monitor feature may be used in a variety of ways, depending on the system design requirements and capabilities. Note: Intel requires the Thermal Monitor and Thermal Control Circuit to be enabled for all Pentium 4 processor on 90 nm process -based systems. The thermal control circuit is intended to protect against short term thermal excursions that exceed the capability of a well designed processor thermal solution.
Thermal Requirements R 3.4.8 Legacy Thermal Management Capabilities In addition to Thermal Monitor, the Pentium 4 processor on 90 nm process supports the same thermal management features originally available on the Intel Pentium III processor. These features are the on-die thermal diode and THERMTRIP# signal for indicating catastrophic thermal failure. 3.4.8.1 On-Die Thermal Diode There are two independent thermal sensing devices in the Pentium 4 processor on 90 nm process.
Thermal Requirements R 3.4.9 Cooling System Failure Warning If desired, the system may be designed to cool the maximum processor power. In this situation, it may be useful to use the PROCHOT# signal as an indication of cooling system failure. Messages could be sent to the system administrator to warn of the cooling failure, while the thermal control circuit would allow the system to continue functioning or allow a normal system shutdown.
Thermal Requirements R Figure 8. Example Thermal Profile 75 70 Heatsink Design Point Case Temperature (C) 65 60 55 Thermal Profile 50 FMB2 45 40 35 30 30 40 50 60 70 80 90 100 110 Watts 3.5.2 TCONTROL TCONTROL defines the maximum operating temperature for the on-die thermal diode when the thermal solution fan speed is being controlled by the on-die thermal diode. The TCONTROL parameter defines a very specific processor operating region where the TC is not specified.
Thermal Requirements R 3.5.3 How On-die Thermal Diode, TCONTROL and Thermal Profile work together The Pentium 4 processor on 90 nm process thermal specification is comprised of the two parameters, TCONTROL and thermal profile. The first step is to ensure the thermal solution by design meets the thermal profile. If the system design will incorporate variable speed fan control Intel recommends monitoring the on-die thermal diode to implement acoustic fan speed control.
Thermal Requirements R 3.6.1 Example Implementation The system designer must work with the board designer to select the appropriate fan speed controller. For processor fan speed control the Figure 9 shows the major connections. Figure 9. Example Acoustic Fan Speed Control Implementation 4-Pin Fan Inlet Header Ambient GND (Thermistor) Sys Ambient (Opt) +12V Tachometer HS Fan PWM Processor Sys Fan 4wire PWM (2x) Fan Speed Controller Thermal Diode (2 wires) T control 3.6.
Thermal Requirements R Figure 10. Example Fan Speed Response Templow Temphigh Diode temperature (C) 80 75 70 65 60 55 50 45 40 0 100 200 300 400 500 600 RPM 6000 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 700 RPM Tdiode Time (s) The choice of accelerating the fan speed over a 5 °C range is an aggressive acoustic solution. For the typical home/office ambient environment and workloads, the fan will remain at the minimum operating speed for most workloads.
Thermal Requirements R 3.8 Impacts to Accuracy A number of issues can affect the accuracy of the temperature reported by thermal diode sensors. These include the diode ideality and the series resistance that are characteristics of the processor. The processor datasheet provides the specification for these parameters. The trace layout recommendations between the thermal diode sensors and the processor socket should be followed as listed the vendor datasheets.
Thermal Requirements R This page is intentionally left blank.
Intel® Thermal/Mechanical Reference Design Information R 4 Intel® Thermal/Mechanical Reference Design Information 4.1 Intel® Validation Criteria for the Reference Design 4.1.1 Thermal Performance 4.1.1.1 Reference Heatsink Performance Target Table 2 provides the heatsink performance target for loadline A and loadline B Pentium 4 processor on 90 nm process.
Intel® Thermal/Mechanical Reference Design Information R 4.1.1.2 Acoustics To optimize acoustic emission by the fan heatsink assembly, it is recommended to develop a solution with a variable speed fan. A variable speed fan allows higher thermal performance at higher fan inlet temperatures (TA) and lower thermal performance with improved acoustics at lower fan inlet temperatures.
Intel® Thermal/Mechanical Reference Design Information R 4.1.2 Fan Performance for Active Heatsink Thermal Solution The fan power requirement for proper operation is a maximum steady state current of 740 mA at 12 V. In addition to comply with overall thermal requirements (Section 4.1.1), and the general environmental reliability requirements (Section 4.1.3) the fan should meet the following performance requirements: • The expected fan minimum functional lifetime is 40,000 hours at 45 °C.
Intel® Thermal/Mechanical Reference Design Information R Figure 11. Random Vibration PSD 0.1 3.13GRMS (10 minutes per axis) PSD (g^2/Hz) (20, 0.02) (500, 0.02) (5, 0.01) 0.01 5 Hz 500 Hz 0.001 1 10 100 1000 Frequency (Hz) 4.1.3.1.2 Shock Test Procedure Recommended performance requirement for a motherboard: • Quantity: 3 drops for + and - directions in each of 3 perpendicular axes (i.e., total 18 drops). • Profile: 50 G trapezoidal waveform, 170 in.
Intel® Thermal/Mechanical Reference Design Information R 4.1.3.1.3 Recommended Test Sequence Each test sequence should start with components (i.e., motherboard, heatsink assembly, etc.) that have never been previously submitted to any reliability testing. The test sequence should always start with a visual inspection after assembly, and BIOS/CPU/Memory test (refer to Section 4.1.3.3). The stress test should be then followed by a visual inspection and then BIOS/CPU/Memory test. 4.1.3.1.
Intel® Thermal/Mechanical Reference Design Information R 4.1.3.3 Recommended BIOS/CPU/Memory Test Procedures This test is to ensure proper operation of the product before and after environmental stresses, with the thermal mechanical enabling components assembled. The test shall be conducted on a fully operational motherboard that has not been exposed to any battery of tests prior to the test being considered.
Intel® Thermal/Mechanical Reference Design Information R 4.1.5 Safety Requirements Heatsink and attachment assemblies shall be consistent with the manufacture of units that meet the safety standards: • UL Recognition-approved for flammability at the system level. All mechanical and thermal enabling components must be a minimum UL94V-2 approved. • CSA Certification. All mechanical and thermal enabling components must have CSA certification.
Intel® Thermal/Mechanical Reference Design Information R 4.2 Reference Thermal Solution for the Intel® Pentium® 4 Processor on 90 nm Process The Pentium 4 processor on 90 nm process will re-use the reference thermal solution for the Pentium 4 processor with 512-KB L2 cache on 0.13 micron process at 3 GHz and above. Note that the ability to re-use the 3GHz and higher Pentium 4 processor with 512-KB L2 cache on 0.
Intel® Thermal/Mechanical Reference Design Information R Figure 13. Exploded View of Reference Thermal Solution Components (with Optional Fan Guard) Note: Intel reserves the right to make changes and modifications to the design as necessary. Note: The thermal mechanical reference design for the Pentium 4 processor on 90 nm process will be validated according to the Intel validation criteria given in Section 4.
Intel® Thermal/Mechanical Reference Design Information R 4.2.2 Reference Mechanical Components 4.2.2.1 Heatsink Attach Clip The heatsink attach clip for the Pentium 4 processor on 90 nm process reference heatsink consists of a one-piece plastic clip (LEXAN* 500ECR) identical to that used for the Pentium 4 processor with 512-KB L2 cache on 0.13 micron process reference heatsink. A drawing of the clip is provided in Appendix C. 4.2.2.
Intel® Thermal/Mechanical Reference Design Information R 4.2.2.7 Fan Guard An optional fan guard is available and is shown in the heatsink assembly drawings in Appendix C. The heatsink thermal performance was validated without the fan guard attached. The fan guard is intended to protect personnel from the fan blades during operation. 4.
Intel® Thermal/Mechanical Reference Design Information R This page is intentionally left blank.
Appendix A: Thermal Interface Management R Appendix A: Thermal Interface Management To optimize a heatsink design, it is important to understand the impact of factors related to the interface between the processor and the heatsink base. Specifically, the bond line thickness, interface material area and interface material thermal conductivity should be managed to realize the most effective thermal solution.
Appendix A: Thermal Interface Management R This page is intentionally left blank.
Appendix B: Intel Enabled Reference Thermal Solution R Appendix B: Intel Enabled Reference Thermal Solution This appendix includes supplier information for Intel enabled vendors for the Pentium 4 processor on 90 nm process reference thermal solution. The reference component designs are available for adoption by suppliers and heatsink integrators pending completion of appropriate licensing contracts. For more information on licensing, please contact the Intel representative below. Table 5.
Appendix B: Intel Enabled Reference Thermal Solution R Table 7. Licensed Intel Reference Component Thermal Solution Providers Supplier Part Description Contact/Geo Phone E-mail AVC Integrated Thermal Solution Vincent Lee / (N. America) 310-783-5484 vincent@avc.com.tw CCI Integrated Thermal Solution Harry Lin/ (N. America) 714-739-5797 ackinc@aol.com Foxconn Integrated Thermal Solution Julia Jiang / (N. America) 408-919-6178 juliaj@foxconn.
Appendix C: Mechanical Drawings R Appendix C: Mechanical Drawings The following table lists the mechanical drawings included in this appendix. These drawings refer to the thermal mechanical enabling components for the Pentium 4 processor on 90 nm process. Note: Intel reserves the right to make changes and modifications to the design as necessary.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 14.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 15.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 16.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 17.
Figure 18.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 19.
Figure 20.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 21.
Figure 22.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 23.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 24. Heatsink Assembly (Non-validated Fan Guard Shown.
Intel® Pentium® 4 on 90 nm Process Thermal Design Guide Figure 25.
Appendix C: Mechanical Drawings This page is intentionally left blank.
Appendix D: TCASE Reference Metrology R Appendix D: TCASE Reference Metrology The procedure for attaching thermocouples to the Thermal Test Vehicle (TTV) for use in thermal experiments is described in this appendix. A repeatable and accurate thermocouple attach process reduces overall experimental variation, cuts down on preparation time for measurements, and most importantly yields robust temperature measurements.
Figure 26.
Appendix D: TCASE Reference Metrology R Thermocouple Attach Procedure The following items are required for thermocouple removal or reattach. Table 8. Thermalcouple Attach Material List Thermalcouple Attach Material List Scribe Fine point tweezers Exacto* knife (#11 blade) Thermocouple (36 gauge, 0.9 m [36 in], Teflon insulation) 3M Kapton* tape cut into strips (3 mm x 13 mm [0.125 in x 0.
Appendix D: TCASE Reference Metrology R Thermocouple Positioning Position the thermocouple on the part using the following process. 1) The TTV surface must be thoroughly cleaned in order to ensure a strong bond between the epoxy and the surface of the part to which the thermocouple is being attached. Clean the TTV surface with alcohol using a lint-free wipe or swab. Figure 28.
Appendix D: TCASE Reference Metrology R 5) Lift the wire at the middle of channel with tweezers and bend the front of wire to place the thermocouple in the channel ensuring the tip is in contact at the bottom end of the groove of the IHS. See Figure 30. Figure 30. Thermocouple Attach Preparation 6) Important! Using an ohmmeter, measure the thermocouple electrical resistance. The thermocouple resistance should be 25 Ω or less.
Appendix D: TCASE Reference Metrology R Epoxy Application Apply the epoxy to attach the thermocouple using the following procedure. 1) Use a scribe or an Exacto* knife to apply the epoxy over the bead in the channel. If an Exacto knife is used, a #11 blade is recommended because the blade has a sharp point and can also act as a small trowel. Apply epoxy over the bead and on the exposed thermocouple wires. Very little epoxy is needed to attach the thermocouple.
Appendix D: TCASE Reference Metrology R 4) Remove parts and allow them to cool. Remove all tape and check for any unwanted epoxy dots or lines. Use the Exacto* knife to remove the extraneous epoxy from the surface. 5) Using an ohmmeter, measure the thermocouple electrical resistance to ensure a value of 25 Ω or less. 6) Trim the excess glue from the IHS surface as shown below. CAUTION! Be sure not to damage the surface of the IHS. Any deep scratches can cause erroneous test results. Figure 33.
Appendix D: TCASE Reference Metrology R 8) Inspect the final package for any remaining glue particles. Figure 35.
Appendix E: TTV Metrology R Appendix E: TTV Metrology Thermal Test Vehicle (TTV) Information Introduction The Pentium 4 processor on 90 nm process Thermal Test Vehicle (TTV) is a FC-mPGA4 package assembled with a thermal test die. The TTV is designed for use in platforms targeted for the Pentium 4 processor on 90 nm process. Thermal solution performance should be characterized using the TTV.
Appendix E: TTV Metrology R TTV Connections for Power-Up The TTV heater is connected to external pins and can be powered by an external DC power supply. The resistance heater of the thermal die is terminated at the power and ground pins of the package (VCC and VSS). The power and ground pin-out of the TTV match the power and ground pin-out of the actual processor, allowing use of a standard motherboard for power-up.
Appendix E: TTV Metrology R The heater can be accessed by soldering wires to the power and ground sides of one of the capacitor pads. This establishes connections between the power supply and power/ground planes on the motherboard. Since the heater is a simple resistor, the polarity of the power supply connection is arbitrary. Figure 39. Power Supply Connection to Motherboard Measure the resistance between the power and ground planes with the socket empty to make sure that the planes are separated (i.e.
Appendix E: TTV Metrology R Thermal Measurements Refer to Section 3.3.2 for TA measurement methodology. Refer to Appendix D for thermocouple attachment to the HIS. Use the following instructions for performing thermal characterization parameter measurements using the TTV: 1. Attach a thermocouple at the center of the package (IHS-side) using the proper thermocouple attach procedure (refer to Appendix D). 2. Connect the thermocouple to a meter or data logger. 3.
Appendix E: TTV Metrology R 7. 8. Refer to Section 3.3.2 to setup the thermocouples used for TA measurement, and connect them to a thermocouple meter or data logger. Set the voltage of the DC power supply to the value calculated from the targeted power level and the heater resistance, if the DC-power supplier uses a voltage-control mode (e.g., Voltage = 9. Heater Resistance × Power ).
Appendix E: TTV Metrology R TTV Correction Factors for Intel® Pentium® 4 Processor on 90 nm Process Thermal characterization parameter measurements made with a thermal test vehicle must be corrected for the non-uniform power dissipation of actual processors. Table 10 provides correction factors for using a Pentium 4 processor on 90 nm process TTV to assess the thermal characterization parameter of Pentium 4 processor on 90 nm process heatsinks.
