JP2805311B2 - Multi-stage electronic cooler - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cascade-type multi-stage electronic cooler in which thermoelectric element pairs having a Peltier effect are sequentially cascaded via a substrate. .

[Prior Art] The above-mentioned multi-stage electronic cooler has, for example, six stages as shown in FIG. 1, and thermoelectric element pairs A for N-type semiconductor 1 and P-type semiconductor 2 are alternately arranged in each stage. When the thermoelectric element pairs A of each stage are energized, the upper substrate side of each stage absorbs heat, and the uppermost substrate is absorbed. 3a is cooled at the maximum temperature. The ratio of the logarithm of the thermoelectric element pair A in each stage is such that, assuming that the uppermost stage is 1, the number of the thermoelectric element pairs A is gradually increased toward the lower stage.

[Problems to be solved by the invention]

The problem of the above-mentioned multi-stage electronic cooler is that the power consumption is large instead of the heat absorption capability. This tendency becomes larger as the number of stages is increased in order to lower the maximum attainable temperature.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides a multi-stage electronic cooler capable of achieving high performance and compactness with a constant increase ratio of power consumption in each stage. It is intended for.

[Means for solving the problem]

In order to achieve the above object, a multi-stage electronic cooler according to the present invention comprises a thermoelectric element pair A having a Peltier effect,
In a cascade-type multi-stage electronic cooler that is cascaded sequentially from the first stage to the n-th stage via the
When m ₁ , m _2, ... _mn , the thermoelectric element pairs A are sequentially increased from the first stage to the n-th stage, and the thermoelectric element pairs A for each stage are increased.
Are set so that the difference in the logarithmic increase rate m (= m _n / m _n-1 ) falls within the range of 0.5.

(Operation)

The performance of the multi-stage electronic cooler is roughly classified into i) attained temperature and ii) coefficient of performance = heat absorption / power consumption. One of the factors that greatly affect these factors is the increase ratio of the power consumption of each stage. The difference in the increase ratio m of the logarithm of the thermoelectric element pair in each stage is set to be within 0.5. Thus, the increase ratio m 'of the power consumption of each stage can be kept constant or as close to a constant value as possible within the range permitted by the configuration, whereby the intended high-performance multistage electronic cooler can be obtained. it can. When the thermoelectric element pairs of the same size are used, the number of pairs of thermoelectric element pairs in one lower stage can be approximately increased sequentially at a constant rate m. If there are stages with different capacities of the thermoelectric element pairs, the logarithm thereof is corrected according to the capacities so as to have the constant ratio m.

〔Example〕

 Embodiments of the present invention will be described below.

The six-stage multi-stage electronic cooler shown in FIG.
Metallized AlN is used, and thermoelectric element pair A is Bi-T
Using e and changing the logarithm of each stage of the thermoelectric element pair A as shown in Table 1, two units of the first embodiment and the second embodiment were manufactured. The N-type and P-type semiconductor elements 1.2 of each pair constituting each thermoelectric element pair A had the same capacity of 1.7 square × 2.3 height.

As shown in Table 1, the logarithm of the thermoelectric element pair A in each stage is sequentially increased, and the logarithm of the thermoelectric element pair A in each of the first to nth stages is represented by m ₁ , m _{2 ,.} Then, the increase ratio m of the logarithm of each stage is represented by _mn / _mn-1 . As shown in the table, the increase ratio m is 2.0 in the first embodiment,
In the embodiment, m = 2.0 to 2.5.

As shown in FIG. 1, three radiation preventing plates 5a, 5b, 5c covering the second and higher stages from the bottom were attached to the multistage electronic coolers of the first and second embodiments. . Each of the radiation prevention plates 5a, 5b, 5c has a top opening 6a, 6b, 6c facing the top of the cooler. Each of the radiation preventing plates 5a, 5b, and 5c was formed by attaching a 1 μ gold foil to a 12 μ copper foil.

The multi-stage electronic cooler constructed as above is installed at 300 ゜ K (27
(° C.) and set in a vacuum bell jar at 10 ⁻⁶ Torr.

Then, from the top openings 6a, 6b, 6c of the radiation prevention plates 5a, 5b, 5c
The infrared light correctly measured at 0.02 W was applied to the top of the cooler. In this state, correct the heat load of the multi-stage electronic cooler to 0.
Performance could be measured while keeping 02W constant.

In the above state, the multistage electronic coolers of both examples were energized, and the optimum current for cooling the top substrate to the lowest temperature was determined.

As a result, as shown in Table 1, in the first example, the optimum current was 3.0 A, and the top at this time reached -87 ° C.

In the second embodiment, the optimum current is 3.2 A and the top is-
95 ° C was reached.

(Comparative example)

The multi-stage electronic coolers of the first and second comparative examples in which the m values as shown in Table 2 were used, that is, the ratio of the m value in each stage was made indefinite with the same material and manufacturing method as the first and second embodiments. Was made.

In the first and second comparative examples, the performance was measured in exactly the same manner as in Examples 1 and 2 with the radiation prevention plate attached, as shown in Table 2. The optimum current is 2.9A, 3.2A, the top temperature is -78 ° C,
It was only -82 ° C.

FIG. 3 shows the above results in terms of the power consumption W of the cooler and the maximum temperature (top temperature) ° C.

In the figure, a and b are the first and second examples, and c and d are the first and second examples.
It is a comparative example.

In general, if the thermal load is constant, the maximum attainable temperature tends to increase as the power consumption of the cooler increases. The increase rate m 'of the power consumption of each stage is constant or approaches a constant value. As a result, as shown in FIG. 3, the first and second embodiments have lower power consumption and lower power consumption. The maximum attainable temperature can be achieved.

Note that, in both the above-described embodiment and the comparative example, an example is shown in which the semiconductor elements constituting the thermoelectric element pairs A of the respective stages have the same capacity, but as shown in FIG. You may use what changed the capacity.

In this case, when the m value of each stage is 2, the logarithm of each stage does not become a multiple of 2 depending on the size of the semiconductor element as shown in the figure.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the increase rate of the power consumption of each stage becomes substantially constant, As a result, a low maximum attainable temperature can be realized with low power consumption, and thereby a high performance and compact multi-stage electronic cooler Can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of a multi-stage electronic cooler to which an anti-radiation plate is attached, and FIG. 2 is a diagram showing the case where the capacities of the elements used are different and the increasing ratio of thermoelectric element pairs in each stage is constant. FIG. 3 is a diagram showing the logarithm of the stages, and FIG. 3 is a diagram showing the relationship between the power consumption, the maximum attained temperature, and the rate of increase of the thermoelectric element pairs in each stage. A is a thermoelectric element, 1 and 2 are semiconductor elements, 3 is a substrate, 4 is an electrode, 5a, 5b and 5c are radiation prevention plates, and 6a, 6b and 6c are top openings.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Toru Yamaguchi 1200 Manda, Hiratsuka-shi, Kanagawa Pref. Komatsu Ltd. Research Laboratory (56) References Japanese Utility Model Application Sho 61-110838 (JP, U) Japanese Patent Publication No. 43-18426 (JP) , B1) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01L 35/32 F25B 21/02

Claims (1)

(57) [Claims] 1. A cascade type multi-stage electronic cooler in which thermoelectric element pairs A having a Peltier effect are sequentially cascaded from a first stage to an n-th stage via a substrate 3 and cascaded. The logarithm of the thermoelectric element pair A of each stage is
When m ₁ , m _2, ... _mn , the thermoelectric element pairs A are sequentially increased from the first stage to the n-th stage, and the thermoelectric element pairs A for each stage are increased.
A multi-stage electronic cooler characterized in that the difference of the logarithmic increase ratio m (= m _n / m _n-1 ) is within the range of 0.5.