KR20010071917A - Temperature control of electronic devices using power following feedback - Google Patents

Abstract

A method of controlling the device temperature measures a parameter related to the device power consumption and uses this parameter to control the device temperature. This can be achieved by a system comprising a heat exchanger, a power monitor, and a circuit for controlling the temperature setting of the heat exchanger. This circuit utilizes power levels, heat exchanger temperature, and set point as input signals. Thus, the system does not require temperature sensing elements connected to or within the chip, responding to the temperature of the device rather than the package, can be used for large chip fabrication, and has a significantly large surface area of the device And does not require chip power profiles. As a salient feature, this system allows the set point to be maintained with minimal overshoot or undershoot.

Description

TECHNICAL FIELD [0001] The present invention relates to electronic device control using power-dependent feedback,

The present invention relates to temperature control systems that maintain the temperature of an electronic device at or near a set point temperature while the device is being operated or inspected. Two examples of electronic components that work best at a certain temperature or near constant temperature are packaged integrated chips and unpackaged bare chips.

Keeping the chip temperature near a certain set point is not so difficult if the power dissipation of the chip changes within a constant or small range during chip operation or inspection. A way to deal with this case is to couple the chip to a thermal mass at a fixed temperature through a fixed thermal resistance. However, if the instantaneous power consumption of the chip changes to a large range up or down during operation or inspection of the chip, it becomes very difficult to keep the chip temperature near a certain set point.

Various temperature-enforcing systems are used to respond to chip temperature fluctuations caused by power dissipation in widely varying chips. Feedback methods are commonly used to detect changing temperatures. A typical approach involves the use of a temperature sensing element such as a chip package or a thermocouple mounted on the chip itself. Another approach involves integrating a temperature sensing element, such as a thermal diode, into the chip circuit. These thermal sensing elements are used to sense chip temperature changes and to properly adjust the temperature constraint system.

There are several problems with the use of temperature sensing elements. In the case of packaged chips, the externally mounted thermocouple will display the temperature of the package surface, not the temperature of the chip inside the package. At significant power consumption levels, these temperature differences will be important to the test results. The use of temperature sensors integrated in the chip itself addresses this problem, but also raises other issues. It is not uncommon for chip makers to integrate temperature sensors on a chip. Even so, the temperature sensors on each chip will have unique calibration requirements. All of the above-mentioned problems also apply to rough chip manufacturing.

Temporary temperature sensors such as thermocouple probes included in automated test handling equipment may be aimed at several of these issues. However, package temperature versus die temperature issues will still remain. Also, the reliability of the temporary temperature sensor introduces errors that have a significant effect on the results of a large number of chip fabrication tests. Moreover, the surface that can be used for temperature control is the same as the surface required for the temporary temperature sensor, which further complicates the problem.

Thus, a need has arisen for a temperature control apparatus and method for an electronic device capable of responding to the temperature of an electronic device without a package. There is also a further need for a temperature control device and method for electronic devices that can be easily used in large chip manufacturing. There is a further need for a reliable temperature control device and method for electronic devices. There is a further need for a temperature control apparatus and method for electronic devices that does not require a significant surface area of the electronic device. There is a further need for a temperature control device and method for electronic devices that does not require temperature sensing elements that are integrated into the chip or that need to be temporarily contacted with the chip. There is no need to acquire, maintain and apply chip power profiles, and there is no need for additional requirements for temperature control devices and methods for electronic devices that do not require the ability to perform these tasks in automated test equipment, temperature enforcement systems, There is also a need.

The present invention is directed to overcoming or at least alleviating the effects of one or more of the problems described above.

This application claims priority from prior provisional application serial number 60 / 092,720, filed July 14, 1998, which is incorporated herein by reference in its entirety.

The present invention relates generally to the field of temperature control, and more particularly to an improved apparatus and method for providing temperature control of electronic components using power following feedback.

FIG. 1A is a block diagram illustrating an embodiment of the present invention.

1B is a block diagram illustrating several key components of a thermal control board according to an embodiment of the present invention.

2 is a block diagram illustrating power calculation and monitoring circuitry in one embodiment of the present invention.

3 is a block diagram illustrating a thermal control circuit of an embodiment of the present invention.

4 is a graph illustrating the results of power dependent temperature control in accordance with an embodiment of the present invention.

5 is a graph showing the performance of the forced air system.

6 is a graph showing the performance of a simple conduction system.

Figure 7 includes a graph illustrating the performance of power dependent temperature control in accordance with one embodiment of the present invention.

Figure 8 includes a graph illustrating the effect of self-heating on uncontrolled and non-self-heating on the performance distribution of an element lot.

Figure 9 is a high-level block diagram illustrating the interrelationship between the inspection control system, the temperature control system, and the devices.

10A-10C are high-level block diagrams illustrating acquisition and use of device power information.

Figure 11 shows a thermal control unit.

According to the present invention, there is provided a temperature control apparatus and method for an electronic device that substantially eliminates or mitigates disadvantages and problems associated with previously developed temperature controls for electronic devices.

An advantage of the present invention is that it provides a temperature control apparatus and method for an electronic device capable of responding to the temperature of an electronic device without a package.

Another advantage of the present invention is that it provides an apparatus and a method for temperature control for electronic devices that can be easily used for mass production of chips.

A further advantage of the present invention is that it provides a reliable temperature control apparatus and method for electronic devices.

Another advantage of the present invention is that it provides a temperature control apparatus and method for an electronic device that does not require a significant surface area of the electronic device for temporary monitoring of the package temperature.

Another advantage of the present invention is that it does not require temperature sensing elements to be integrated into the chip or temporarily connected to the chip for temperature control during mass production.

Another advantage of the present invention is that there is no need to acquire, maintain and apply chip power profiles, as well as the ability to automatically test equipment, temperature enforcement systems and inspection software to collect and apply chip power profiles I do not.

Briefly, in accordance with one aspect of the present invention, a method of controlling the temperature of a device is provided. The method includes measuring parameters related to power consumption by the device and utilizing the measured parameters to control the temperature of the device. Measurement of parameters and temperature control occur simultaneously. This parameter is anything other than the temperature of the device, and the associated power consumption is the power consumed by the device through the power connection to the signal connections.

Briefly, in accordance with another aspect of the present invention, a method for calculating a real-time temperature of a device is provided. The method includes measuring the real-time power usage of the device and utilizing the measured real-time power usage of the device in determining a value that can be used for real-time temperature of the device. This power usage is related to the power used by the device through one or more power connections to the signal connections.

Briefly, in accordance with another aspect of the present invention, a method is provided for controlling the temperature of a device in a system including a temperature-constraining system coupled to the device. The method includes monitoring the power consumption of the device, adjusting the temperature of the temperature-sensitive system based in part on the monitored power consumption of the device, and controlling the device temperature with the temperature-forced system. This power consumption relates to the power supplied to the device by one or more power supplies.

Briefly, in accordance with another aspect of the present invention, a system for controlling the temperature of a device is provided. The system includes a measuring element for measuring parameters related to power consumption by the element, a heat exchanger adapted to be coupled to the element, and a thermal controller for determining the setting of the heat exchanger. This setting is determined in part by using measured parameters related to power consumption by the device. The thermal controller is coupled to the measuring element and operates simultaneously. This parameter is anything other than the temperature of the device, and the associated power consumption is the power consumed by the device through the power connection to the signal connections.

Briefly, in accordance with another aspect of the present invention, a system for controlling the temperature of a device is provided. The system includes a structure for measuring parameters related to the power consumption by the device and a structure for controlling the temperature of the device based in part on the measured parameters related to the power consumption by the device. The measurement of the parameters related to the power consumption by the device and the temperature control of the device occur simultaneously. This parameter is anything other than the temperature of the device, and the associated power consumption is the power consumed by the device through the power connection to the signal connections.

Briefly, in accordance with another aspect of the present invention, a data generation system for use with a semiconductor device under test is provided. The data generation system includes a programmable power supply and a data acquisition element. A programmable power supply is for supplying a data signal that includes information about the power used by the semiconductor device during powering and powering semiconductor devices under test. The data acquisition element is for acquiring data on the power used by the semiconductor device under test by accepting a data signal from a programmable power supply.

Briefly, according to another aspect of the present invention, a method of generating data for use with a semiconductor device under test is provided. The method includes continuously supplying a data signal from a programmable power supply. The data signal includes real time information about the power supplied to the semiconductor device under test by the programmable power supply. The method further comprises, in the data acquisition device, continuously receiving the data signal from the programmable power supply.

Briefly, in accordance with another aspect of the present invention, there is provided a temperature control system for use with a semiconductor device under test. The temperature control system includes a measuring element, a heat exchanger, a thermal controller, and an inspection head. The measuring device is for measuring a parameter related to the power consumption by the semiconductor device under inspection. This parameter is other than the temperature of the semiconductor device, and the associated power consumption is the power consumed by the semiconductor device through the power connection, as opposed to the signal connections. The heat exchanger is made suitable for coupling to a semiconductor device. The thermal controller is for determining the setting of the heat exchanger, which is determined in part by using the measured parameters related to the power consumption by the device. The thermal controller is coupled to the measuring element and simultaneously operates in time. The inspection head enables the inspection of the semiconductor element while the semiconductor element makes conductive contact with the heat exchanger and the setting of the heat exchanger is determined by the thermal controller.

The above and other aspects of the present invention will become more apparent from the description of the embodiments when considered in conjunction with the accompanying drawings. The drawings illustrate embodiments of the invention. In the drawings, the elements of the drawings are designated by the same reference numerals.

Mooring patent application U.S.S.N., filed by Pelissier and assigned to the present assignee. 08 / 734,212 are incorporated herein as fully described herein. Jones et al., Co-pending U.S.S.N., filed on July 14, 1998, and assigned to the present assignee. 60 / 092,715 (Attorney Docket No. 042811-0104) is also incorporated as fully described herein.

1. Core Theory

When the device is inspected, the inspection needs to be performed at a specific temperature, which is known as the set point. The device, also referred to as a device under test (" DUT "), is typically examined at several different setpoints and its performance is recorded at each setpoint. The performance of the DUT is often measured as the maximum operating frequency, f _max , at a given set point. DUTs are typically faster (higher f _max ) at lower temperatures and slower (lower f _max ) at higher temperatures. A higher _fmax indicates a better performance DUT, and therefore a more expensive DUT.

It is becoming increasingly difficult to maintain a given set point. One of the reasons is the self-heating of the DUT that occurs during the test. DUTs self-heat as they draw power during the test. If the DUT can not be maintained at the setpoint during the test run, it will become hot and, as indicated above, the performance of the DUT will deteriorate. This leads to a bad evaluation of the performance of the DUT, because if the temperature was maintained at the desired low temperature, the performance would have been better. The same device will then be sold at a higher price. The device cost is normally increased exponentially in proportion to the faster device. Thus, this impact is significant for manufacturers who, of course, must accept badly rated performance.

The number of affected devices is also exponentially related to the temperature increase due to self-heating. As pointed out in Fig. 8, the performance distribution of a given plurality of elements is normally normalized to some center frequency. 8, this center frequency is approximately 450 MHz for the rightmost curve. In this example, high performance devices are believed to have a f _max of 480 MHz or higher.

If the set point can be maintained, then all the elements in the rightmost curve at the right tail of 480 MHz will be high performance devices. However, if the set point can not be maintained because of self-heating, then the curve will move and form, for example, the leftmost curve. In this example, the actual junction point temperature of the device is expected to increase to 20 占 폚, which will result in a reduction in performance of approximately 4%. Thus, the distribution of the elements of this lot is shifted to the left, centered at approximately 432 MHz (4% of 450 = 18). This shifted curve is indicated by the leftmost curve. However, high performance devices are still required to have a f _max of 480 MHz or greater. Thus, the high-performance region of the curve moves further toward the tail of the distribution. As can be clearly seen from the area under the curve, the number of high-performance elements is now reduced in proportion to the exponential function.

This problem can get worse. Industry trends are moving in the direction of allowing devices to operate at higher frequencies and occupy a smaller area. This allows the devices to use more power, has greater power spikes or transitions, and reduces the ability to dissipate the heat they generate.

Many semiconductors utilize complementary metal oxide semiconductor (" CMOS ") technology. One of the characteristics of CMOS is that it causes a large spike in power when switching states. Furthermore, as CMOS devices operate at higher speeds, the devices will typically switch faster and more frequently. This will require more power and will result in large and fast changes in instantaneous power consumption. Therefore, more heat will be generated.

This situation is exacerbated by the reduction of device size and thermal mass. This results in less "space" in which the heat of the device can diverge or diffuse. The end result is a larger variation in DUT temperature due to self-heating and an increase in bad ratings for DUT performance.

The convection system proved to be ineffective, though it gave them improvements. Referring to FIG. 5, the performance of the forced air system is shown when analyzed in terms of junction temperature in the device and power drawn by the device. As the power drawn by the device increases, the junction temperature shift from the desired set point also increases. As can be seen, in some of the advantages, this shift exceeds 20 ° C.

While providing a potential advantage over the convection system, the conduction system proved ineffective. Referring to Figure 6, the performance of a simple conduction system for a flip chip device is shown. As the power drawn by the device increases, the temperature also increases beyond the nominal temperature of about 60 ° C.

A true solution requires the ability to quickly sense the temperature of the DUT and its ability to respond quickly and effectively to temperature changes in the DUT.

As described in the present application, the two requirements are referred to by the disclosed invention. They provide a mechanism to quickly determine the DUT temperature using a newly developed power-dependent feedback technique. This disclosure also provides a heat source / sink (collectively, heat exchanger " Hx ") that can respond to quickly and effectively cancel out the self-heating of the DUT. Referring to FIG. 7, a reduced overshoot at the DUT temperature that is partially achieved by the rapid response to the determined DUT temperature is shown. This response is shown by the heat exchanger temperature reflecting the power to the DUT as a reverse image.

The heat-dependent feedback method used to determine the DUT temperature also works in real time so that it can optimize the test sequences without changing the thermal conditioning and without thermal conditioning limiting the testing program flexibility I have. The main characteristic is to develop and use a simplified formula that allows the extraction of the DUT temperature from the power measurement.

It will be apparent to one of ordinary skill in the relevant art (s) in view of this disclosure that it is desirable to measure, so-called, the total power usage of the DUT, although this is not always necessary. Obviously, there are embodiments where a fraction of the power can be estimated or ignored. For example, without limitation, if all the power fluctuations of a device are isolated to a particular voltage or power supply, or if a particular power supply supplies a relatively small amount of power to the device, this will happen.

Furthermore, monitoring the power supply is an easy way to monitor power usage because it detects instantaneous power fluctuations before the connection is removed from the DUT and before the actual change in self-heating occurs. These power fluctuations can be increased or decreased and can cause an increase or decrease in self-heating. However, one of ordinary skill in the art will appreciate that there are other ways to monitor power, current, and / or voltage.

2. Power Following System

Figure 1A shows an embodiment of the present invention. The monitoring circuit 10 monitors the amount of power used from one or more power supplies 15 that provide power to the electronic device (not shown) during operation or during operation. If there are multiple power supplies 15, the monitoring circuit 10 sums to obtain the total power usage. The electrical connection point 16 connects the monitoring circuit 10 to each power supply 15. The electrical connection point 16 provides the monitoring circuit 10 with a power usage indication of the electronic device, such as a voltage image of the current flowing through the electronic device and a voltage level when the electronic device is operated or inspected . The electrical connection points 16 are useful in the power supplies of automated test equipment used to inspect electronic components. The monitoring circuit 10 sends a power consumption signal 20 (voltage representing the power consumption value) to the thermal control circuit 25. [

Based on a signal indicative of a given chip setpoint temperature or setpoint temperature 30 and a signal indicative of the forced system surface temperature or the forced system surface temperature 32, the thermal control circuit 25 generates a global usage signal 20 To the temperature control signal (35). The thermal control circuit 25 sends a temperature control signal 35 to the heat exchanger temperature controller 40. The heat exchanger temperature controller 40 includes a heat exchanger power supply (not shown) with a power amplifier and controls the output current of the heat exchanger power supply to adjust the output current of the heat exchanger 45 Temperature is controlled. The resulting temperature of the heat exchanger is the forced system surface temperature (32).

Referring to FIG. 1B, a thermal control circuit 25 is present on the thermal control board 27. The thermal control board 27 also includes a first precision constant current source 28 and a second precision constant current source 29 rather than other components. The first precision constant current source 28 sends a precise constant current from the thermal control board 27 to the variable resistance element (" RTD ") in the heat exchanger 45. The RTD outputs a voltage indicative of the forced system surface temperature 32 in response to the forced system surface temperature. The forced system surface temperature low pressure 33 is fed back to the thermal control circuit 25. Placing the first precision constant current source 28 outside the heat exchanger 45 provides an advantage in that the heat exchanger can be replaced more easily.

The second precise constant current source 29 can send a precise constant current to the DUT. The heat exchanger 45 is described in more detail in the following temperature control unit section.

The present invention is described in co-pending patent application U.S.S.N., by Jones et al. 60 / 092,715. ≪ / RTI >

As one of ordinary skill in the relevant art will readily appreciate, in light of this disclosure and the integrated disclosure, the functions of the overall system may be implemented with various techniques. Although electronic circuits are described herein for monitoring and thermal control circuits, other implementations are possible for these functions as well as for others such as generating signals representative of current, voltage, temperature and power.

According to an aspect of the present invention, the functions disclosed herein may be implemented by hardware, software, and / or both. Software tools may be written in any suitable language, including, but not limited to, advanced programming languages such as C ++, intermediate and lower level languages, assembly language, application specific or device specific languages. Such software may be executed on a general purpose computer, such as a 486 or Pentium, an application specific hardware part, or other suitable device.

In addition to using discrete hardware components in the logic circuitry, the desired logic may be implemented by an application specific integrated circuit (ASIC) or other device. The technique may use analog circuits, digital circuits, or a combination of both. The system may also include various hardware components well known in the art, such as connectors and cables. Moreover, at least a portion of the functionality may be stored on a computer readable medium (also referred to as a computer program product) that is used to program an information-processing apparatus for performing in accordance with the present invention, such as magnetic media, magneto-optical media, ). This function may also be embodied in computer program products or computer readable media, such as transmission waveforms used to transmit information or functions.

Further, it will be apparent to those of ordinary skill in the art that the present invention may be applied to various other fields, applications, industries, and techniques, through this disclosure. The present invention can be used without limitation with any power application system where the temperature must be monitored or controlled. This includes many other processes and applications related to semiconductor fabrication, inspection, and operation.

In addition, the preferred embodiment calculates or monitors the power supplied to the DUT from the power supply. Through one or more power connections in the DUT, this power is typically provided at a power level or grid on the DUT. It should be distinguished from the power inherent in any signal. Obviously, any signal connection to the device is designed to accept a signal of a particular power, such as a clock signal. However, the power monitored by the preferred embodiment is the power provided to the power connections at the power supply, and not the power specific to the signal that can be supplied to the signal connection. The power supply used above can be referenced to a standard industrial device capable of providing a specific voltage of electrical power to operate the device. However, it is apparent that the techniques of the present invention can be applied to any signal that includes power signal, clock signal, and data signal without limitation. These techniques may also be applied to non-standard power supplies.

3. Monitoring circuit sum function

2 is a block diagram illustrating the calculation function of the monitoring circuit 10 in an embodiment of the present invention in which an electronic device is powered from a plurality of power devices 15. [ Each of the electrical connections 16 (not shown in FIG. 2, see FIG. 1A) connects the current 210 and the voltage signals 215 to a corresponding power supply 15 (not shown in FIG. 2, To the monitoring circuit (10). Each current and voltage signal 210, 215 passes through a respective first amplifier 220 where it is amplified and enters a low-pass filter 225 that removes the high-frequency components of the signal and the light-band noise. The current and voltage signals 210 and 215 may have the form of voltages representing the values of each current or voltage.

The thermal components of the system respond later (e.g., milliseconds) than the power supplied to the electronic device under test responds (e.g., nanoseconds). Therefore, the high frequency components of the current and voltage signals 210 and 215 do not contribute to increasing the value. Eliminating the high frequency components of the current and voltage signals 210 and 215 matches the bandwidth of the current and voltage signals 210 and 215 to the bandwidth of the rest of the control circuitry and simplifies the task of stabilizing temperature control .

The current and voltage signals 210 and 215 for a particular power supply are then passed together by a first multiplying circuit 230 which is used to calculate the current consumption for the particular power supply And voltage signals 210 and 215, respectively.

For all power supplies, the monitoring circuit 10 uses the following equation (1) to calculate the power usage from the current and voltage signals 210,

[Equation 1]

P = I * V

here:

- P is the power usage in watts,

I is the current signal in amperes,

- V is the voltage signal in volts.

If the power supply 15 provides a voltage image of the current drawn by the electronic device, then a scaling factor is needed to account for the voltage-to-amperage relationship of the voltage-phase signal. If the electronic device is inspected, the scaling factor is extracted from the characteristics of the power supply to the automatic inspection equipment used to inspect the electronic device (and also to power the electronic device during operation or inspection). For example, Schlumberger's VHCDPS has a scaling factor of 1.0, while Schlumberger's HCDPS has a scaling factor of 0.87. This scaling factor is made available in the monitoring circuit so that the signal in volts can be converted to the corresponding current in amps.

The scaling factor is determined experimentally by the following formula.

Scaling factor = signal volt / measured amperage value

This can be done by measuring the actual current and signal voltage value simultaneously and then dividing the voltage value by the measured ampere value. In some embodiments it is possible to measure the signal volt value after setting one or more specific current output values.

The output from all first integrating circuits 230 passes through a single summation circuit 235, which sums the power usage from all the power supplies to produce a power usage signal 20. The power usage signal 20 may have the form of a volt unit representing its value and leave the monitoring circuit and pass through the second amplifier 240 before entering the thermal control circuit as the power usage signal 20. [

4. Thermal control circuit

3 is a block diagram illustrating a thermal control circuit of the present invention. The temperature of the electronic device being inspected or operating can be determined using the following equation:

&Quot; (2) "

Chip temperature = K _theta * P _ed + T _fss .

here,

- Chip temperature (° C) represents chip temperature extracted from its power consumption.

- K _theta is the thermal resistance of the medium between the electronic component and the heat exchanger (or the media if the heat spreaders, lids or other components are attached to the top of the component itself) (° C / watt) that is derived from the possible output of the reactor.

- P _ed (watts) is the total power usage reflected in the power usage signal 20 obtained from the monitoring circuit 10 (see FIG. 1A).

- T _fss (° C) is the system surface forced temperature and is the absolute temperature of the medium in contact with the chip as measured by a temperature sensor inserted into the surface of the thermal control system.

K _theta may also be extracted from the general efficiency of the thermal control system upon contact with the DUT. For example, at a set point temperature that is considerably higher than room temperature, the DUT loss is proportionally drained to its surroundings, and the thermal control system must operate harder to raise the DUT temperature than to lower the temperature. From the point of view of the heat control system responding to the DUTs self-heating, the overall effect is the same as the low heat resistance between the DUT and the heat exchanger operating at room temperature set point. Likewise, at set point temperatures considerably lower than room temperature, the DUT obtains heat from its surroundings, and the thermal control system must work harder to lower the temperature than raise the temperature. From the point of view of the heat control system responding to the DUTs self-heating, the overall effect is the same as the high heat resistance between the DUT and the heat exchanger operating at room temperature set point. In both cases, K _theta is adjusted to reflect the heat transfer effect on the ambient environment of the DUT during power excursion.

K _theta can be considered as the effective or fine-tuned thermal resistance of the medium. Although the thermal resistance of different media is presented in standard chemical reference books (e.g., CRC Handbook of Chemistry and Physics, 77 ^th Edition; David R. Lide, Editor-in-Chief) Can affect the actual thermal resistance. Thermal resistance can also be affected by the physical configuration of the test. To determine K _theta , we can use a calibration process to adjust the predicted thermal resistance value of the medium and see if the result is improved. Another advantage of the calibration process is that it will automatically account for the "efficiency factor" of heat transfer from the DUT to the thermal control system as a function of set point temperature.

As described above, K _theta provides the advantage of integrating the effects of various variables into one term. In a preferred embodiment, K _theta only needs to be optimized for the given application, i.e. the kind of DUT, and then it can be used to inspect many other elements of the same kind. In addition, a practical effect of K _theta is the method as reflected in the monitored power consumption of the device as the temperature of the temperature forcing system (see Fig. 7), K _theta is that increase or decrease the relative size of the reflection.

In the thermal summation circuit 330, the temperature control signal 35 is determined using the following equation:

&Quot; (3) "

V _tcs = d (V _sp - ((V _{k -theta} * V _Ped ) + (V _fsst - V _IRO ) / V _alpha )) / dt,

here,

- V _tcs is the temperature control signal.

- _Vsp is the set point temperature voltage 375, which is the voltage representing the set point temperature for the electronic device.

- V _k-theta is the voltage (315) representing the K _theta value. The K _theta value is input to the digital-to-analog converter, which generates a voltage corresponding to the input value.

_- V _Ped is the total power usage signal 20 obtained from the monitoring circuit 10 (see FIG. 1A) and representing the wattage consumed by the DUT.

_- V _fsst is the forced system surface temperature voltage (32) generated by the digital-to-analog conversion and representing the forced system surface temperature.

_- V _IRO 345 is a voltage generated by a digital to analog conversion that is applied to a variable resistive element in a heat exchanger at 0 ° C to a precise constant current from a first precision constant current source 28 in a thermal control board 27 Lt; RTI ID = 0.0 > value. ≪ / RTI > This can be determined when the temperature sensor inserted in the heat exchanger is calibrated.

_- V _alpha (360) is the voltage produced by the digital analog conversion, which represents the slope of the resistance versus temperature curve of the variable resistive element in the heat exchanger. This can be determined when the temperature sensor inserted in the heat exchanger is calibrated.

3, the power usage signal 20 from the monitoring circuit 10 (not shown in FIG. 3) enters the thermal control circuit 25 by passing through the third amplifier 310. From this, The signal 20 passes through a second integration circuit 320 where the signal is multiplied by V _{k -theta} 315 to produce a first modified signal. The modified power usage signal then passes through a fourth amplifier 325 and into a thermal summing circuit 330 here. The voltage V _fsst (32) representing the forced system surface temperature also enters the thermal control circuit 25 by passing through the fifth amplifier 335. From there, V _fsst 32 enters a subtraction circuit 340 that subtracts V _IRO 345 from V _fsst 32 for the calibrated V _fsst . The calibrated V _fsst passes through a sixth amplifier 350 and into a divisional circuit 335 where the calibrated V _fsst is divided by V _alpha 360. (V _fsst - V _IRO ) / V _alpha passes through the seventh amplifier 365 and from there through the thermal summation circuit 330, where it is summed with the modified power usage signal to yield the sum I'll do it. This sum is passed through a difference circuit (or subtraction circuit) 375, which subtracts this sum from the set point temperature voltage 370 to produce a resultant signal. This signal represents an instantaneous temperature error.

The resulting signal passes through a differentiating circuit 380 where the time derivative of the resulting signal is made and smoothed. This differential signal is amplified by the sixth amplifier 390 before leaving the thermal control circuit as the temperature control signal V _tcs (35).

The differentiating circuit 380 represents the entire control area of the thermal control circuit 25. This is where the response time of the circuit to the instantaneous signal level is determined. Although characterized by the differentiating circuit 380, the control circuit 25 can be described as a PI type control loop because the control circuit 25 has proportional and integral gain stages.

In other embodiments, true PID control can be used, for example, by designing a custom system or using a commercially available servo controller. These systems add capabilities such as continuous ramping, s-curve profiling, servo tuning for minimum overshoot and undershoot, and improved closed-loop control stability. Depending on the particular controller used, the PID controller may need to convert the temperature signal and the power signal to a kind of thermal position signal, which may need to be padded back into the commercial servo motor controller have. Some controllers may need to do some conversion at the back end. As noted in these examples, the required control functions can be performed by analog and / or digital circuits.

5. Graph example

4 is a graph showing an example of the power dependent temperature control method of the present invention. This graph shows that the temperature of the electronic device 410 can be kept fairly constant even when the amount of swings in the amount of power 420 used by the electronic device is widened.

6. Inspection control and temperature determination

As described in the opening paragraph, the control system maintains the DUT temperature within a given tolerance to a certain set point. Therefore, the control system must have some information about the DUT temperature. Some control systems, such as the direct temperature dependence method, require repeated DUT temperature information. Other control systems, such as the power dependent method of controlling deviation from the set point, do not require repeated DUT temperature information, but must know when the temperature maintenance operation has begun.

In one embodiment, the power dependent operation is initiated after the DUT reaches the set point temperature. This information can be determined indirectly, for example, after the silence timer expires. For example, this may be determined directly by monitoring the thermal structure. The thermal structures may be used to provide an initial DUT temperature and they may be monitored throughout the test if they are properly calibrated. One embodiment of the present invention monitors the thermal structures to determine the starting DUT temperature before starting the power dependent temperature control method.

Characterization and validation operations are performed for power dependent temperature control of a particular type of DUT. This operation utilizes die temperature information. If a statistically sound sample set is obtained with true die temperature information during the calibration process, there is no need to place a temperature sensing element in the die during mass production and inspection.

Embodiments of the present invention may include separate control sections to control temperature and control the sequence of the test. 9, there is shown a comprehensive high-level block diagram illustrating the inspection control system 130 and the temperature control system 132 both connected to and in communication with the DUT 134. As shown in FIG. This disclosure was primarily concerned with describing the temperature control system 132. The inspection control system 130 performs appropriate checks on the DUT 134 while the temperature control system 132 controls the DUT temperature.

These two control systems 130, 132 either need to communicate with each other or need to coordinate their functions. The temperature control system 132 or the inspection control system 130 may monitor the thermal structure. In one embodiment of the present invention, the inspection control system 130 monitors the thermal structure of the DUT 134 and sends a signal, such as a voltage scaled to the temperature control system 132, which indicates the DUT temperature. 9 shows the communication path of this embodiment as a dotted line between the inspection control system 130 and the temperature control system 132. As shown in Fig. The embodiments of these control systems and their configuration can vary considerably. In one embodiment, the two control systems 130, 132 are separate and not in direct communication. All of the control systems 130 and 132 monitor the DUT 134 to obtain the DUT temperature information needed to adjust their function. In the second embodiment, the two control systems 130 and 132 are fully integrated.

7. Data Acquisition

The information utilized by the power-dependent system described above is information about the power draw of the DUT. In the illustrated embodiment, this information is a scaled voltage image of the current and voltage signals, as shown in Figure 1A. These signals are supplied by the power supply (s) 15 of Fig. This information may be made available for other purposes, using a data generation system. Such a data generation system can display power information such as the shape of plots of graphs, perform calculations for various applications based thereon, monitor performance and efficiency, and specify some possible situations And stores the data. Various data generation systems are shown in Figures 10a-10c.

Referring to FIG. 10A, a power supply 15 for supplying power to the DUT 134 is shown. Preferably, the power supply is a programmable power supply. A data acquisition card 136 is also shown that accepts power information, such as scaled voltage phases of current and voltage signals from the power supply 15, and more generally referred to as a data acquisition element. In some embodiments, the data acquisition card 136 may accept information, such as information received by the monitoring circuit 10 of FIG. 1A. This signal (connecting the power supply 15 through the connection point 16 to the monitoring circuit 10 in FIG. 1A) may be supplied to the data acquisition card 136 by various methods known in the art, A method for branching a line to the monitoring circuit 10 or daisy-chaining the data acquisition card 136 is not limited.

Referring to FIG. 10C, the monitoring circuit is preferably installed between the power supply 15 and the data acquisition card 136. The data acquisition card 136 then receives the power usage signal 20 from the monitoring circuit 10. In this embodiment, the data acquisition card 136 acquires the power usage signal 20 directly, without relying on other elements or processors to perform calculations or perform calculations. The various power usage signals 20, which are the scaled voltage phases of the power, are shown in FIG. 4 (Chip Power), 5 (ActualPwr), 6 (Power Mon), and 7 (Power to DUT). In these figures, signals are acquired by the data acquisition cards 136.

The data acquisition card 136 may utilize analog and / or digital circuitry. Preferably, the data acquisition card 136 includes an analog-to-digital converter with multiple channels. One embodiment uses an available board of model number PCI-6031E made by National Instruments for data acquisition card 136. [

The data acquisition card 136 may perform various control functions such as setting a sampling rate and other parameters. However, in the preferred embodiment, the data acquisition card 136 sends data to another controller. In each of FIGS. 10B and 10C, a general purpose personal computer ("PC") 138 is shown that functions as a controller as well as sets various values for the data acquisition card 136. In one embodiment, the PC 138 may receive the digitized data from the data acquisition card 136 and the PC 138 may execute the various services and functions with the data. In one embodiment, the data may be stored in a digital storage medium such as, for example, a hard disk, a floppy disk, an optical disk, a ZIP disk, or a Bernoulli drive. The data is also transferred and displayed on a display device such as a computer screen or processed. Other embodiments may also include additional processors or equipment, including analog equipment, which utilize the data.

Preferably, the PC 138 includes a Pentium processor and uses a Windows NT operating system. Various communication cards and protocols may be used between the PC 138 and the data acquisition card 136, including but not limited to Universal Asynchronous Receiver Transmitter (UART), Universal Receiver Transmitter (URT), and RS- do.

In a preferred embodiment, the data acquisition card 136 also acquires a variety of different information, including but not limited to DUT temperature information, heat exchanger power information, flow rate per coolant hour, and fluid input and output temperatures.

8. Temperature control unit

Figure 11 shows a general diagram of a system 110 in accordance with the present invention. As shown, the user activates the system 110 in the operator interface panel 112. The operator interface panel 112 serves as an interface to the system controller 114. System controller 114 is housed within thermal control chassis 116 and controls heat exchanger 120 and liquid cooling and recirculation system 122.

The heat exchanger 120 preferably includes a heater and a heat sink. However, other types of heat exchangers are possible. The heat sink preferably includes a chamber through which liquid is pumped. Other types of heat sinks are also possible. Heat sinks that do not use liquids, or heat sink systems, can be used if the thermal conductivity is high enough. In particular, solid heat sinks such as Peltier devices are known in the art to use electrical signals that pass through their material to control temperature and temperature gradients. The heat sink can also be referred to as a heat transfer unit as a synonym, thereby focusing attention on the fact that the heat sink can also act as a heat source.

The heater of the heat exchanger 120 is preferably a three layer co-fired aluminum nitride heater substrate with a heater trace between the first two layers and an RTD trace between the last two layers. The heater traces provide heat and the RTD traces provide temperature information. The two traces are electrically isolated, although in essentially the same thermal location due to the thermal conductivity of the aluminum nitride layers.

In discussing the temperature of a heater, heat sink, or other device, it should be understood that the temperature of a single point on the device is being discussed. This is obvious from the fact that a conventional heater, or a heat sink or other element, will have a temperature gradient along its surface. In the case of a heater, the presence of a temperature gradient is partly due to the fact that the exothermic component occupies only a portion of the heater.

The liquid cooling and recirculation system 122 supplies the liquid to the heat exchanger 120, specifically the heat sink, via a boom arm 118. In addition, the boom arm 118 delivers control signals from the system controller 114 to the heater.

The inspection head 121 is fabricated to fit under the heat exchanger 120. The inspection head 121 preferably includes a test socket, such as a chip, which is used to mate with a device under test (" DUT "). Inspection of the DUT may then be performed via the inspection head 121 and the temperature of the DUT may be controlled during inspection. During temperature control, the DUT preferably makes conductive contact with the heat exchanger 120.

9. Variation and Profit

Embodiments of the present invention may include time delay or filtering on the power usage signal 20 or elsewhere to adjust the effect of power compensation over time. This can be used, for example, to offset the effects of large ceramic substrates or other large thermal heat sinks or to average them without eliminating the effects of high frequency power signals. The faster testers and microprocessors become, the more time delay and filtering becomes more important.

Other embodiments also compensate for large bypass capacitances for the tester interface board or the DUT itself. Bypass capacitances are used to provide instantaneous charge that the power supply can not recharge quickly enough due to inductive loads or physical distances. As the bypass capacitances increase, the time between the power supply signal and the DUT self-heating will decrease.

While the above embodiments use analog design techniques, digital signal processors and software may be used in alternative embodiments of the present invention for performing them in a digital manner.

An advantage of the present invention includes providing a temperature control apparatus and method for an electronic device capable of responding to the temperature of an electronic device without packaging. A further benefit of the present invention is that it provides an apparatus and method for temperature control for electronic devices that can be easily used for manufacturing large quantities of chips. A further advantage of the present invention is that it provides a reliable temperature control device and method for electronic devices.

A further benefit of the present invention is that it provides a temperature control apparatus and method for an electronic device that does not require a significant surface area of the electronic device to sense the device temperature, even though the system does not require a surface area for conduction. Another advantage of the present invention is that there is no need for temperature sensing elements to be integrated into the chip or temporarily connected to the chip.

It is a further advantage of the present invention that there is no need to collect, maintain and apply chip power profiles as well as the need for capabilities in automatic test equipment, temperature enforcement systems and inspection software to collect and apply chip power profiles It is not.

The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The present invention should not be construed as being limited to the specific forms disclosed, as they are considered to be illustrative rather than limiting. Moreover, modifications and variations can be made by those of ordinary skill in the art without departing from the spirit and scope of the invention.

Claims (30)

A method for controlling temperature of a device comprising: Measuring parameters other than the temperature of the device such that the parameter is related to the power consumption by the device and the associated power consumption is the power consumed by the device through a power connection opposing the signal connections ; And utilizing the measured parameter to measure the temperature of the device so that the measurement of the parameter and the control of the temperature occur at the same time. 2. The method according to claim 1, wherein the step of measuring a parameter related to the power consumption by the device comprises monitoring the power consumption of at least a part of the device. The method of claim 1, wherein the step of measuring a parameter related to power consumption by the device comprises monitoring a power supply supplying power to the device and measuring voltage and current from the power supply. Control method. 2. The method of claim 1, wherein the step of measuring a parameter related to the power consumption by the device comprises monitoring a change in the instantaneous power consumption of the device. 3. The method of claim 2, wherein monitoring the power usage of at least a portion of the device comprises monitoring the total power usage of the device, wherein the monitored total power usage is utilized to control the temperature of the device Wherein the temperature control method comprises the steps of: 2. The method of claim 1, wherein the step of measuring parameters related to power consumption by the device comprises: Generating a signal indicative of a first current usage of the device; Generating a signal representative of a first voltage corresponding to a first current usage of the device; And multiplying the signal representing the first voltage by a signal representing the first current usage to generate a signal indicative of a first power consumption of the device. 7. The method of claim 6, wherein the step of measuring parameters related to power consumption by the device comprises: Generating a signal indicative of a second current usage of the device; Generating a signal indicative of a second voltage corresponding to a second current usage of the device; Multiplying a signal representative of the second current usage and a signal representative of the second voltage to generate a signal indicative of a second power usage of the device; Further comprising: summing a signal indicative of a first power usage of the device to a signal indicative of a second power usage of the device to generate a signal indicative of the summed power usage of the device Way. 2. The method of claim 1, wherein controlling the temperature of the device based on a measurement parameter associated with power consumption by the device comprises: Utilizing a temperature constraint system; And controlling a set value of the temperature forced system based at least in part on a measurement parameter associated with power consumption by the device. 9. The method of claim 8, wherein controlling the set point of the temperature constraining system comprises using a first equation that substantially determines the temperature of the element, wherein the first equation is: Temperature control method: Temperature of the device = K _theta * P _ed + T _fs . 10. The method of claim 9, wherein controlling the set point of the temperature constraining system further comprises using a second equation to generate a signal used to control the temperature constraining system, Wherein the equation is as follows. V _tcs = d (V _sp - ((V _{k -theta} * V _Ped ) + (V _fsst - V _IRO ) / V _alpha )) / dt, Where V _tcs is the signal used to control the temperature constraint system. 7. The method of claim 6, wherein the step of measuring parameters related to power consumption by the device comprises: Processing a signal indicative of a first current usage of the device; Further comprising the steps of: processing a signal representative of a first voltage corresponding to a first current usage of the device, wherein the signals are processed before the two signals are multiplied with each other. 9. The method of claim 8, wherein controlling the set point of the temperature constraining system comprises using an analog circuit. The method according to claim 8, wherein the step of controlling the set value of the temperature forced system includes executing PID control. A method for calculating a real-time temperature of a device, Measuring a real time power usage of the device such that the power usage is related to the power used by the device through one or more power connections to the signal connections; And using the measured real-time power usage of the device in determining a value that can be used for the real-time temperature of the device. 15. The method of claim 14, wherein measuring the real-time power usage of the device comprises measuring the total power usage. CLAIMS What is claimed is: 1. A system for controlling temperature of a device in a system comprising a temperature-induced system coupled to the device, the method comprising: Monitoring the power consumption of the device so that the power consumption is related to the power supplied to the device by one or more power supplies; Adjusting the temperature of the temperature constraining system based at least in part on the monitored power consumption of the device; And controlling the device temperature with the temperature forced system. 17. The method of claim 16, wherein monitoring the power consumption of the device comprises monitoring the total power consumption of the device. 17. The method of claim 16, wherein adjusting the temperature of the temperature constraining system comprises reflecting the monitored power consumption of the device to the temperature of the temperature constraining system. A system for controlling temperature of a device, Wherein the parameter is related to a power consumption by the device, and the power consumed by the device through a power connection, wherein the associated power consumption is opposite to the signal connections, A measuring device for measuring the temperature of the sample; A heat exchanger adapted to be coupled to the element; And a thermal controller for determining the setting of the heat exchanger such that the setting is partially determined by using a measured parameter related to the power consumption by the element and the thermal controller is coupled to the measuring element at the same time Wherein the temperature control system operates. 20. The temperature control system according to claim 19, wherein a measuring element for measuring a parameter related to the power consumption by the element includes a monitor for monitoring a power consumption of the element. 21. The system of claim 20, wherein the monitor monitors the total power usage and the parameter associated with the power consumption by the device comprises the total power usage. 20. The method of claim 19, Wherein the measuring element comprises: At least one current measuring element for monitoring the current supplied to the element by one or more power supplies; At least one voltage measuring element for monitoring a voltage supplied to the element by one or more power supplies; A monitoring circuit coupled to the at least one current measurement element and the at least one voltage measurement element for generating a power usage signal from the monitored current and voltage, Characterized in that the thermal controller for determining the setting of the heat exchanger comprises a thermal control circuit utilizing the following equation to estimate the temperature of the element: Temperature of the device = K _theta * P _ed + T _fs , Where P _ed is the generated power usage signal. A system for controlling temperature of a device, Means for measuring a parameter other than the temperature of the device, wherein the parameter is related to a power consumption by the device, and wherein the associated power consumption is the power consumed by the device through a power connection, A measuring means for measuring the temperature of the sample; And means for controlling the temperature of the device based in part on the measured parameter related to the power consumption by the device, wherein the measurement of the parameters related to the power consumption by the device and the temperature control of the device occur simultaneously Features a temperature control system. A data generation system for use with semiconductor devices under test, comprising: A programmable power supply for supplying a data signal comprising power to the semiconductor device under test and information about power used by the semiconductor device under test; And a data acquisition element coupled to the programmable power supply and adapted to receive data signals from the programmable power supply to thereby obtain data on power used by the semiconductor device during the inspection. Generating system. 25. The apparatus of claim 24, further comprising monitoring circuitry installed between the programmable power supply and the data acquisition element, the monitoring circuitry receiving data signals from the programmable power supply and outputting a power usage signal to the data acquisition element And wherein the device under test is an integrated circuit. 25. The apparatus of claim 24, further comprising a computer communicatively coupled to the data acquisition element and including a digital storage medium and a display device, the computer receiving a digital power usage signal from the data acquisition element, Storing information from the power usage signal on the digital storage medium and displaying information from the digital power usage signal on the display. A data generation method for use with a semiconductor device under test, Continuously supplying a data signal from a programmable power supply such that the data signal includes real time information about power supplied to the semiconductor device during testing by the programmable power supply; And in the data acquisition device, continuously receiving a data signal from the programmable power supply. 28. The method of claim 27, wherein the power usage signal is an analog signal and the method comprises: Continuously processing the received data signal before it is received by the data acquisition element, thereby generating a power signal indicative of the power used by the semiconductor element under examination; Supplying the power signal to the data acquisition element; Sampling the power signal by the data acquisition element; And supplying the sampled power signal from the data acquisition element to a computer. A temperature control system for use with a semiconductor device under test, Wherein the parameter is related to the power consumption by the semiconductor device during the test and wherein the associated power consumption is determined by comparing the power consumption of the semiconductor device to the semiconductor device through a power connection, A measuring device for causing the power consumed by the power supply to be consumed; A heat exchanger adapted to be coupled to the semiconductor device; A thermal controller for determining a setting of the heat exchanger, wherein the setting is partially determined by using a measured parameter related to the power consumption by the element, and the thermal controller is coupled to the measuring element, A thermal controller to operate; And an inspection head which fixes the semiconductor element during inspection and makes the semiconductor element conductive in contact with the heat exchanger and enables inspection of the semiconductor element while the setting of the heat exchanger is determined by the thermal controller And the temperature control system. 32. The method of claim 29, wherein the heat exchanger maintains the semiconductor device at or near a first temperature during a first inspection of the semiconductor device and then during the second inspection of the semiconductor device, Wherein the heat controller is adapted to be adapted to control the heat exchanger to maintain the heat exchanger close to the heat exchanger.