JP4710239B2 - Natural air-cooled electronic device unit and temperature judgment method - Google Patents

Description

The present invention relates to a temperature measuring device for a natural air-cooled electronic device unit and a temperature measuring method for the electronic device unit.

  Natural air-cooled electronic devices are becoming more and more miniaturized, and as a result, a large amount of heat is generated. Conventionally, as a countermeasure, as shown in FIG. 3, the inside of the electronic device unit 1 is cooled by convection heat transfer, and heat from a component (heating device) 3 that locally generates heat is heated to the outer case (enclosure outer box) 2. A structure is adopted in which it is conducted and cooled in its outer case. That is, the outer case 2 is made of a metal plate or the like, and the heat generated by the heat generating device 3 that generates relatively high heat, such as a CPU or a semiconductor element, is radiated to the outside through the heat generating surface of the outer case 2. In addition, electronic device parts that generate relatively little heat or are not generated (hereinafter referred to as internal components) are arranged in the electronic device unit so that an air flow indicated by arrows is formed. Reference numeral 5 denotes an internal part that does not generate heat, and hatched 6 denotes an internal part that generates heat. Reference numeral 4 denotes a printed board.

  In the electronic device unit 1, convection heat is transmitted in the direction of the arrow.

  As another example, some recent high heat generation CPU devices have a temperature sensor mounted inside the device, and the die temperature is measured and used for controlling the operation mode (operation frequency changes) and monitoring abnormal temperatures. is there.

Further, as shown in FIG. 5, a temperature sensor 7 is provided on the intake side of the unit to measure the intake air temperature (ambient temperature) as a typical unit temperature, and the entire unit is protected based on this measured temperature. Some have a system configuration.
JP-A-11-272341

  In the cooling structure as shown in FIG. 3, in the case of monitoring by the detected temperature Tp of the high heat generating device 3, this temperature Tp greatly depends on the cooling characteristics of the outer case 2. On the other hand, the unit internal components 5 and 6 largely depend on the heat generation amount (internal component temperature Ts) of the internal components, the intake air temperature Ta, etc. in addition to the outer case temperature, but not on the device temperature Tp. . Therefore, although the temperature of the high heat generating device 3 itself can be monitored at the device temperature Tp, the internal components 5 and 6 cannot be monitored.

  FIG. 4 shows this state. The vertical axis indicates the internal component temperature Ts, and the horizontal axis indicates the value of Ts in Tp monitoring when the high heat generating device temperature is taken.

  That is, in the case of monitoring only Tp, since Ts cannot be monitored by Tp, an area of Ts ≧ Tsmax exists even if Tp ≦ Tpmax.

  Next, as shown in FIG. 5, when the temperature sensor 7 is mounted in the unit intake section and the temperature monitoring control is performed using the measured temperatures Ta and Tp detected by the sensor, the internal component temperature Ts This is the temperature Ta plus the component temperature rise ΔTs. FIG. 6 shows this state, where Ts = Ta + ΔTs.

  Since ΔTa depends on component heat generation, cooling effect, etc., the temperature of Ts cannot be calculated even if Ta is measured. Therefore, it is necessary to set the maximum allowable intake air temperature Tamax as a value calculated from the value ΔTsmax at the time when the maximum ΔT is set (worst condition). That is, Tamax = Tsmax (part maximum allowable temperature) −ΔTsmax.

  Since Tamax obtained by subtracting the maximum temperature rise value ΔTsmax of the component is a small value, the unit for temperature control monitoring by this method has a problem that the allowable temperature is lowered.

  Accordingly, an object of the present invention is to provide an electronic device unit and its monitoring sensor that can realize temperature monitoring control according to mounting conditions and can realize a unit having a high temperature specification without lowering product reliability. An object of the present invention is to provide a method for determining an allowable temperature.

In the first aspect of the present invention, an electronic device component is disposed inside an outer case made of metal, and the electronic device component is naturally air-cooled, and the generated heat of the heat generating device that generates relatively high heat in the electronic device component is generated. In an electronic device unit that dissipates heat through the outer case,
The electronics unit respectively provided temperature sensor inside the heat exhaust side to the heating device, a temperature sensor provided in the measured exhaust gas temperature Th and the heating device at a temperature sensor provided in the heat exhaust side measures the device temperature Tp The allowable temperature area is increased in response to the temperature rise of the heat generating device, and when the measured exhaust temperature Th and device temperature Tp are within the allowable temperature area, the electronic device component temperature and the device temperature are temperature allowable. It is characterized by determining that it is within the range .

In the second aspect of the present invention, an electronic device component is disposed inside an outer case made of metal, and the electronic device component is naturally air-cooled, and the generated heat of the heat generating device that generates relatively high heat in the electronic device component is generated. In an electronic device unit that dissipates heat through the outer case,
A temperature sensor is provided on each of the heat exhaust side and the heat generating device inside the electronic device unit, and the exhaust temperature Th measured by the temperature sensor on the heat exhaust side and the device temperature Tp measured by the temperature sensor provided on the heat generating device. Is input to the electronic device component temperature when the measured exhaust temperature Th and device temperature Tp are within the obtained temperature allowable area. The device temperature is within the allowable temperature range .

According to a third aspect of the present invention, the calculation unit uses the measured exhaust temperature Th, device temperature Tp , and electronic equipment component Ts, and moves from the device temperature due to the temperature difference between the exhaust temperature Th and the device temperature Tp to the heat exhaust side. When the temperature rise coefficient is A,
Th = {1 / (1 + A)} Ts + {A / (1 + A)} Tp
The exhaust gas temperature Th corresponding to the temperature rise of the heat generating device is calculated from the above calculation .

A fourth aspect of the present invention is characterized in that a heat sink is attached to the heat generating surface of the outer case.

  As described above, according to the present invention, it is possible to determine whether or not the component temperature of the entire electronic device unit is within the allowable temperature range. Thermal design is possible.

  In addition, since the temperature monitoring control of the entire unit can be performed with a minimum of two temperature sensors, low-cost temperature monitoring control can be provided.

  The software can be designed to determine whether the temperature measured at two locations is within the permissible area, so the temperature margin of the electronic device unit can be easily adjusted, and the mounting direction of components can be changed in the horizontal direction. In the case of component placement, accurate determination can be made only by changing the parameters of the calculation formula.

  In addition, by attaching a heat sink to the outer case, attaching the outer case heat generating surface to a wall with high heat dissipation performance, etc., improving the cooling performance of the unit and lowering the unit exhaust temperature, it becomes possible to cope with more severe environments It is what has.

  FIG. 1 is a conceptual diagram of an electronic device unit showing an embodiment of the present invention. The same or corresponding parts as those in FIGS. That is, according to the present invention, the temperature sensor 8 is provided inside the exhaust side of the electronic device unit 1 and the temperature sensor 9 is provided in the heat generating device 3. The temperature signal detected by each temperature sensor is introduced into a calculation unit (not shown), and the exhaust gas temperature is calculated using a coefficient value.

  Now, the exhaust temperature detected by the temperature sensor 8 is Th, the device temperature detected by the temperature sensor 9 is Tp, the internal component temperature Ts, and the temperature rise value coefficient that turns from the heat generating device to the exhaust side due to the temperature difference between Tp and Th. Assuming A, the relationship between the temperatures in the thermal circuit of the electronic device unit 1 is (3) from (1) and (2).

Th = Ts + A (Tp−Th) (1)
β = 1 / (1 + A), α = A / (1 + A) (2)
Th = βTs + αTp (3)
The change in the exhaust temperature Th is as follows.

  The exhaust temperature Th depends on the intake air temperature and the internal temperature rise (depends on the internal heat generation amount and the cooling efficiency). Therefore, the internal component temperature Ts is lowered by reducing the heat generation amount of the internal components or the cooling efficiency is increased, and the exhaust temperature Th is also lowered accordingly.

  The present invention utilizes this relationship to monitor the internal component temperature Ts and the heat generating device temperature Tp by measuring Th and Tp.

  FIG. 2 shows a temperature allowable area in which the vertical axis represents the exhaust gas temperature Th and the horizontal axis represents the heat generating device temperature Tp, and the temperature rise due to Tp. As is clear from the figure, the increase in Th (αTp) with respect to the change in Tp is considered. Therefore, the heat generating device 3 and the internal components 5 and 6 have an allowable temperature in a wide area where αTp is corrected in the hatched area. If the measured Th and Tp exist in this area, Both the internal component temperature and the heat generating device temperature are within an allowable range, and reliability can be ensured without being affected by other unit intake air temperature, installation conditions, and the like.

  When the electronic device unit 1 is used in a harsher environment, a heat sink is attached to the heat generating surface 2 ′ of the outer case 2 or the unit is attached to a wall having high heat dissipation performance through the heat generating surface 2 ′. Therefore, it is possible to cope with the problem by improving the cooling performance and thereby lowering the exhaust temperature. That is, since the regulation of the intake air temperature of the electronic device unit 1 is unnecessary, it can be used up to a very high intake air temperature depending on the component mounting state if no temperature abnormality is detected.

The conceptual diagram of the electronic device unit which shows embodiment of this invention. Parts tolerance area diagram by exothermic device temperature and exhaust temperature. The conceptual diagram of the conventional electronic device unit. The permissible relationship diagram of internal component temperature by heat generation device temperature monitoring. The conceptual diagram of the other conventional electronic device unit. The temperature control state diagram by heat-generating device temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic device unit 2 ... Outer case 3 ... High heat generation device 4 ... Print board 5 ... Non-heat generation component 6 ... Heat generation component 7 ... Intake side temperature sensor 8 ... Exhaust side temperature sensor 9 ... Temperature sensor

Claims (4)

Electronic equipment parts are arranged inside an outer case made of metal, and the electronic equipment parts are naturally air-cooled, and heat generated by a heat generating device that generates relatively high heat in the electronic equipment parts is externally passed through the outer case. In an electronic device unit that dissipates heat,
The electronics unit respectively provided temperature sensor inside the heat exhaust side to the heating device, a temperature sensor provided in the measured exhaust gas temperature Th and the heating device at a temperature sensor provided in the heat exhaust side measures the device temperature Tp The allowable temperature area is increased in response to the temperature rise of the heat generating device, and when the measured exhaust temperature Th and device temperature Tp are within the allowable temperature area, the electronic device component temperature and the device temperature are temperature allowable. A method for determining the temperature of a natural air-cooled electronic device unit, wherein the temperature is determined to be within a range . Electronic equipment parts are arranged inside an outer case made of metal, and the electronic equipment parts are naturally air-cooled, and heat generated by a heat generating device that generates relatively high heat in the electronic equipment parts is externally passed through the outer case. In an electronic device unit that dissipates heat,
A temperature sensor is provided on each of the heat exhaust side and the heat generating device inside the electronic device unit, and the exhaust temperature Th measured by the temperature sensor on the heat exhaust side and the device temperature Tp measured by the temperature sensor provided on the heat generating device. Is input to the electronic device component temperature when the measured exhaust temperature Th and device temperature Tp are within the obtained temperature allowable area. And a device for measuring the temperature of a natural air-cooled electronic device unit, characterized in that the device temperature is within the allowable temperature range . The calculation unit uses the measured exhaust temperature Th, device temperature Tp, and electronic equipment component Ts, and A represents a temperature increase coefficient that turns from the device temperature to the thermal exhaust side due to the temperature difference between the exhaust temperature Th and the device temperature Tp. When
Th = {1 / (1 + A)} Ts + {A / (1 + A)} Tp
3. The natural air-cooled electronic device unit temperature measuring device according to claim 2, wherein the exhaust temperature Th corresponding to the temperature rise of the heat generating device is calculated from the above calculation . 4. The temperature measuring apparatus for a natural air-cooled electronic device unit according to claim 2, wherein a heat sink is attached to the heat generating surface of the outer case .

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