JPH09268386A - Method for preventing corrosion of electronic computer and method for operating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preventing the corrosion of an electronic computer capable of reducing the number of frequency for maintenance and imparting high corrosion preventing effect and to provide a method for operating the computer. SOLUTION: In the method, the electronic computer is operated while a semiconductor module is cooled with cooling water by a sealed circulating system. The cooling water contains a corrosion inhibitor, and the corrosion inhibitor in this cooling water is contained by the quantity to be consumed by the formation of a corrosion preventing film on a metallic face in contact with the cooling water in the initial stage of the operation, by the quantity to be consumed by the operation for at least one year and by the remaining quantity equal to the quantity to be consumed by the reaction on the initial stage of the operation after the operation for at least one year. After the prescribed operation, the remaining quantity is measured, and the remaining quantity of regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anticorrosion method and an operating method for a computer including an inhibitor added to cooling water to prevent corrosion.

[0002]

2. Description of the Related Art Iron-based and copper-based materials are often used for electronic computer cooling devices, and inhibitors are usually added to prevent corrosion of these materials. However, inhibitors are consumed by decomposition, reduction, adsorption, etc., so strict concentration control is necessary.

The conventional inhibitor concentration control method is one in which cooling water is directly sampled from a cooling device and measured by chemical analysis, or indirectly, the relationship between the inhibitor concentration and the amount of generated gas is grasped. There is a method of measuring the gas amount and estimating the inhibitor concentration. These methods are used properly depending on the type and device of the inhibitor. The latter is intended to improve the complexity of sampling by a direct method such as chemical analysis.
-37257 is a method of knowing the consumption of the inhibitor by measuring the internal pressure change in the pipe caused by the decomposed gas of the inhibitor.In the case of an inhibitor that does not generate decomposed gas, the corrosion is disclosed in JP-A-52-46552. A method of knowing the inhibitor concentration by measuring the amount of hydrogen gas generated by is shown.

Further, Japanese Patent Publication No. 55-10831 discloses a method of measuring the concentration of benzotriazole by utilizing the reaction between benzotriazole and metal ions. In addition, Japanese Patent Publication No. 32702/1993 describes a method of measuring the degree of deterioration of a copper-based anticorrosive material in a radiator solution for cooling an automobile engine by a change in color density. This measuring method utilizes a precipitation reaction of benzotriazole, which is a copper-based anticorrosive in the radiator solution with ethylene glycol, which accounts for 30% of the radiator solution, and copper ions, and filters the precipitate to remove excess excess. Sodium diethyldithiocarbamate is added to a filtrate containing copper ions, the color-developing compound is extracted with ethyl acetate or the like, and the degree of color development is compared with a reference color sample chart to determine the degree of deterioration.

[0005]

SUMMARY OF THE INVENTION Among the above prior arts,
The indirect method may not be able to accurately determine the concentration of the inhibitor, and the direct method has not been established to directly measure the concentration other than the chemical analysis using an analytical instrument. Especially for inhibitors such as benzotriazole and molybdate, it is difficult to establish the measuring method. Japanese Examined Japanese Patent Publication 55-10
No. 831 and Japanese Patent Publication No. 5-32702 disclose that benzotriazole is precipitated with an excess of copper ions, unreacted copper ions are extracted as a color-forming compound, and the concentration of benzotriazole from the degree of color development of the extract is determined. Although the method of measurement is described, since the extraction step is included, the measurement operation is complicated, and it is not practically suitable as a method of measurement on site. That is, in the cooling device, the operation of the device is not stopped, and complicated operations such as separation and quantification of chemical analysis and analytical instruments are not required, and the inhibitor concentration cannot be easily measured on site. There was a problem.

An object of the present invention is to provide an anticorrosion method and an operating method for a computer, which has a high anticorrosion effect by reducing the maintenance frequency.

[0007]

SUMMARY OF THE INVENTION The present invention provides a corrosion prevention method for a computer operated while being cooled by cooling water by a semiconductor module closed circulation system, wherein the cooling water contains a corrosion inhibitor, and the corrosion inhibitor is The amount consumed in the operation for at least one year during the operation and preferably half or more of the amount consumed in the initial reaction of the operation after the operation for at least one year, and more preferably the amount equivalent thereto. There is a method for preventing corrosion of an electronic computer, which comprises:

Further, the present invention provides a method of operating an electronic computer which is operated while being cooled by cooling water by a semiconductor module closed circulation system, wherein the cooling water contains a corrosion inhibitor, and the corrosion inhibitor is at least during the operation. Having an amount consumed in the operation for one year and preferably at least half of the amount consumed in the reaction in the early stage of the operation after the operation for at least one year, and more preferably an amount equivalent thereto. Operation of a computer characterized by measuring the remaining amount of the corrosion inhibitor at least at a desired time after the one year, and adjusting the content of the corrosion inhibitor remaining after the next desired operation. On the way.

The present invention utilizes a reaction in which a corrosion inhibitor (inhibitor) component reacts with a metal ion at a constant ratio to form a precipitate, and reacts with an excessive amount of the metal ion to remove the unreacted metal ion. In the measuring method, it is preferable to form an unreacted metal ion complex compound to cause color development, and thereby measure the inhibitor concentration according to the degree of color development.

That is, a certain amount of cooling water added with an inhibitor for preventing corrosion of the structural material of the cooling device is sampled, and a predetermined amount of an excessive amount of metal ion is added to the sampled cooling water. It is preferable to precipitate all of the inhibitor, form a complex compound from a solution containing unreacted metal ions to cause coloration, and compare the degree of coloration with a standard solution of known concentration to measure the concentration of the inhibitor.

A certain amount of cooling water, to which benzotriazole is added as an inhibitor of the copper-based material of the cooling device, is sampled, and a predetermined amount of an excess amount of copper ions is added to the sampled cooling water to obtain the cooling water. All the benzotriazole is precipitated, and the solution containing unreacted copper ions is made alkaline to form a copper-benzotriazole complex that causes color development, and the degree of color development is compared with a standard solution of known concentration to measure the inhibitor concentration. Is preferred.

A certain amount of cooling water to which an inorganic molybdate is added is used as an inhibitor of the iron-based material of the cooling device, and an excessive amount of iron ions is added to the collected cooling water. A predetermined amount was added to precipitate all the molybdate, and a solution containing unreacted iron ions was reduced to form a complex compound for color development, and the degree of color development was compared with a standard solution of known concentration to inhibit It is preferable to measure the concentration.

A predetermined amount of iron thiocyanate solution containing an excess amount of iron ions with respect to molybdate is added to precipitate molybdate, and then a tin chloride solution is added to prepare a solution containing unreacted iron ions. It is preferable to reduce and form a complex compound of molybdenum thiocyanate to develop a color.

It is preferable that after the complex compound is formed, it is filtered and the concentration of the inhibitor is measured by the degree of color development of the filtrate.

The fact that the inhibitor component reacts with the metal ion at a ratio of 1: 1 is utilized. The benzotriazole concentration contained in the cooling water is reacted with a higher concentration such as a copper sulfate solution to precipitate benzotriazole, and the solution containing unreacted copper ions is made alkaline to form a copper-benzotriazole complex. , To develop color. The degree of this color development is such that the more benzotriazole is in the cooling water, the lighter it becomes, and the less it is, the darker it becomes.

On the other hand, when the inhibitor is molybdate, it is reacted with a fixed amount of iron thiocyanate solution having a concentration higher than that of the molybdate contained in the cooling water,
By reducing a solution containing unreacted iron ions, a complex compound of molybdenum thiocyanate is formed to develop color. The degree of color development is such that the more molybdate is in the cooling water, the darker it is, and the less it is, the lighter it is.

These are different in the degree of color development between the benzotriazole and the copper sulfate solution and between the molybdate and the molybdenum thiocyanate solution by the above procedure using the same solution as the test solution in advance. By preparing a standard solution and comparing the difference in the degree of color development between the sample solution collected from the cooling water and the standard solution, the inhibitor concentration in the cooling water can be easily measured.

An appropriate amount of cooling water added with an inhibitor to prevent corrosion of the structural material of the cooling device is sampled in an extraction tank, sent to a diluting tank to be diluted with pure water, and then sent to the reaction tank. In this reaction tank, a solution of metal ions that combine with the inhibitor component to generate a precipitated substance is supplied and reacted,
Further, a solution for forming a complex compound that forms a colored complex compound from a solution containing unreacted metal ions is supplied to react and then sent to a filtration tank, and the degree of color development is compared with that of the standard solution and The concentration measurement is completed.

The corrosion inhibitor according to the present invention comprises at least one selected from inorganic oxidant type molybdates, nitrates, nitrites, chromates and tungstates.
It is a mixture of at least one compound selected from the group consisting of organic benzotriazole and its derivative, triazole and its derivative, imidazole and its derivative, benzimidazole and its derivative, mercaptobenzimidazole and its derivative. Good. The concentration range of the inorganic and organic mixed corrosion inhibitors in the cooling medium is 1 × 10 ⁻⁶ mol / l to ¹ × 10 ⁻¹ mol.
/ L, the mixing ratio is preferably 1:10 to 10: 1.

The present inventors have examined a corrosion inhibitor applicable to iron-based and copper-based materials constituting a cooling device. Although benzotriazole (BTA) is an effective inhibitor for copper, it was found that the addition of BTA increases the potential of copper and galvanic corrosion occurs due to the potential difference at the portion where stainless steel and copper are joined. Therefore, we searched for inhibitors that could increase the potential of stainless steel. As a result, it was found that the inorganic oxidizer type inhibitor had an effect to passivate stainless steel and raise the potential. By mixing and adding the inorganic oxidizer type inhibitor and the organic compound forming type inhibitor such as BTA, the inorganic type inhibitor is effective for the iron type and the organic type inhibitor is effective for the copper type. Of course,
It was also effective in corroding the joint between stainless steel and copper, which had been a problem in the past.

The inorganic inhibitors are preferably molybdates, nitrates, nitrites, chromates, tungstates, etc. As organic inhibitors, for example,
Triazole and its derivatives, benzotriazole and its derivatives, imidazole and its derivatives, benzimidazole and its derivatives, mercaptobenzimidazole and its derivatives and the like are preferable. Specific examples of derivatives are shown in Table 1.
Through Table 3, its name and structural formula are shown.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

Further, as an example of the method of controlling the concentration of the corrosion inhibitor, a pair of electrodes made of a metal whose corrosion inhibitor exhibits anticorrosive performance is installed in the cooling water passage, and a frequency of 1 is set between the electrodes.
This can be achieved by applying a minute AC voltage of not less than 1 kHz and not less than 1 Hz and detecting the impedance value of each frequency. From the resistance value between the electrodes of the electrode element, the corrosion resistance value involved in metal corrosion and the resistance value of only the solution are separately obtained, so that the state of the concentration of the corrosion inhibitor can be known.

The resistance component observed between the electrodes involves the resistance Rs of the solution and the resistance value Rc due to the corrosion reaction of the metal electrode. The Rc value can be obtained from the relationship with the corrosion rate Icorr of the metal electrode.

Therefore, the corrosion rate Icorr can be calculated if the corrosion resistance value Rc is known. R above
The AC impedance method is the most suitable method for accurately measuring the c value. This method is a method of applying a high frequency minute AC voltage and a low frequency minute AC voltage between a pair of electrodes and measuring the impedance at each frequency.

That is, the decrease in the corrosion resistance value Rc of copper of the measuring electrode shows the decrease in the concentration of BTA in the mixed corrosion inhibitor, and the increase in the resistance value Rs of the solution increases the molybdenum in the mixed corrosion inhibitor. One can see the decrease in the acid salt concentration.

In this way, the cooling water containing the mixed corrosion inhibitor composed of organic and inorganic materials such as BTA and molybdate is circulated in the cooling device of the electronic computer, and the impedance measurement system and the corrosion inhibitor are injected into the cooling system. By providing a system and a control system for injecting a corrosion inhibitor, it became clear that the cooling device of the electronic computer has high reliability.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a system diagram of a computer cooling device of the present invention. Cooling water 1 is cooling water containing a corrosion inhibitor.
This cooling water 1 is supplied to a plurality of electronic calculators by a pump 2.
The cooling water 3 is sent to the cooling unit 3 of the semiconductor module including the LSI device and heat-exchanged to generate heat. At the same time, the cooling water 1 is heated and flows into the cooling water tank 4. The cooling water 1 discharged from the cooling water tank 4 is sent to the cooler 5 by the pump 2. The cooler 5 is provided with a heat exchanger 7 connected to the refrigerator 6, and the cooling water 1 that has been heated by cooling the heating element of the electronic computer is cooled again in the cooler 5. Then, the cooling water 1 discharged from the cooler 5 is controlled by the flow rate control device 8 and sent to the cooling unit 3 of the electronic computer.
At this time, a valve serving as a cooling water outlet 9 for controlling the concentration of the corrosion inhibitor is installed in the cooling water system.

In FIG. 2, a semiconductor element 16 is mounted on a multilayer circuit board 13 made of a ceramic sintered body of mullite, AlN, alumina or the like, and a heat conducting disk 11 having comb-teeth fins is contacted thereon. FIG. 3 is a partial cross-sectional view showing a semiconductor module structure in which a metal housing 19 made of copper is sealed and He gas is put inside. The heat conduction disk 11 is made of a ceramic sintered body and has a heat conductivity of 0.
An AlN or SiC sintered body having 2 cal / cm · sec. ° C. or higher is preferable. It is preferable that the sintered body contains 0.1 to 3 wt% Be in SiC (especially BeO is preferable). Since the semiconductor element 16 as an integrated circuit generates a large amount of heat, water containing an inhibitor is sent from the cooling port 20 to be cooled, and then sent to the next module from the outlet 21. The metal housing 19 has a double sealed structure on the semiconductor element 16 side and the cooling water side. The semiconductor element 16 side is the heat conduction disk 1
A fin 17 is formed so as to contact the first fin with a gap of micron order. Further, on the cooling water side as well, the cooling water containing the inhibitor flows at a high speed, and fins 17 are provided above and below in order to enhance the cooling efficiency. Since these are made of copper, it is necessary to add an inhibitor as described above. In particular, since the degree of integration of semiconductor devices has been increasing in recent years, the amount of heat generated is high and it is necessary to enhance the cooling efficiency. The flow velocity of cooling water is also higher, and the corrosion protection for that is particularly important.

In FIG. 3, the semiconductor module 24 of FIG. 2 is mounted on a multilayer printed circuit board 25 made of an organic resin such as polyimide via pins, and the multilayer printed circuit board 2 is mounted.
Connector 2 of the platter 26 via the terminals provided on the
7 is a perspective view showing a computer mounting structure in which the semiconductor module 24 mounted on the device 7 is three-dimensionally mounted. FIG.

With such a structure, the computer can be compactly mounted, and the signal processing speed is high because the relative dielectric constant is low as described above.

FIG. 4 shows the effect of BTA concentration on the amount of corrosion of copper in a cooling water environment simulated at 40 ° C. and 2 m / s.
The results obtained by conducting a corrosion test in pure water for 200 hours are shown below. From the figure, corrosion of copper can be suppressed if the BTA concentration is 5 ppm or more. Here, the effective concentration range of the corrosion inhibitor is from 5 ppm to 2
It is × 10 ⁴ ppm. This is because at a low addition concentration, there is no corrosion inhibiting effect, and at a high addition concentration, a precipitate is generated due to the solubility of BTA, and the precipitate floats in the system and adheres to the heat transfer part etc. to reduce the cooling performance. This is because it causes troubles such as.

FIG. 5 and FIG. 6 show the inhibitory effect of the corrosion inhibitor on crevice corrosion and copper corrosion of SUS304 stainless steel, simulating an accelerated environment in the presence of chloride for 10 ^-2 mol / l Na.
The results of the corrosion test conducted in a Cl solution at 60 ° C. for 200 hours are shown below. From the figure, it can be seen that molybdate is highly effective for crevice corrosion of stainless steel and benzotriazole is highly effective for corrosion of copper. Further, the mixed corrosion inhibitor of the present invention has a high corrosion inhibition effect on both stainless steel and copper. Therefore, it is understood that the mixed corrosion inhibitor is good for the system in which the iron system and the copper system coexist. Here, the concentration range of the mixed corrosion inhibitor is from 1 × 10 ⁻⁶ mol / l to 1 ×
It is preferably 10 ^-1 mol / l and the mixing ratio is 1:10 to 10: 1.

This is because at a low addition concentration, there is no corrosion inhibiting effect, and at a high addition concentration, a precipitate is generated due to the solubility of benzotriazole, and the precipitate floats in the system and adheres to the heat transfer tube etc., causing a trouble. This is because The basis of the mixing ratio is shown in Table 4. Any of molybdate, tungstate, and chromate has a corrosion inhibiting effect within the above range.

[0037]

[Table 4]

FIG. 7 shows the results of examining the relationship between the inhibitor concentration and the resistance value. Here, molybdate and BTA were used for the mixed inhibitor, and copper was used for the impedance measurement electrode. 10 kHz was applied between the electrodes on the high frequency side and 10 mHz on the low frequency side. When the relationship between the corrosion resistance value Rc of copper and the solution resistance value Rs is examined from FIG. 7, they are in a linear relationship, and if the inhibitor concentration decreases, the corrosion resistance value of copper of the measurement electrode decreases, and the solution resistance value is Since it becomes large, the inhibitor concentration can be estimated by monitoring this value.

As an inhibitor, an inorganic molybdate, which is effective for iron-based materials, and a benzotriazole, which is effective for copper-based materials, were used for a cooling device. The procedure of the analysis procedure is to collect 100 ml of cooling water, collect 10 ml in a 100 ml volumetric flask, dilute to 70 ml with water, and then add the copper sulfate solution to 1.25 times the estimated amount of benzotriazole (for 200 ppm of benzotriazole). 1 g / l copper sulphate solution (25 ml) was added exactly to precipitate and then 20
% Aqueous ammonia solution (1.5 ml) and add water to 100 m
The solution is made alkaline as 1 to form a copper-benzotriazole complex. Mix well, leave for 10 minutes, and compare the degree of color development of the solution with a standard solution prepared in advance to determine the amount of benzotriazole. In this case, after aging the precipitate, filter the precipitate with filter paper (No. 5C),
A more accurate concentration can be determined by comparing the degree of color development of the filtrate with a standard solution prepared in advance to determine the amount of benzotriazole.

As in the case of benzotriazole, 100 ml of cooling water was collected and placed in a 100 ml volumetric flask.
After taking up 1 ml and diluting with water to 65 ml, an iron thiocyanate solution (mixture of a 1: 4 sulfuric acid solution containing 10 mg of trivalent iron ions and a 10% cyanoammonium solution) was added to an estimated amount of molybdate. Accurately add 1.25 times the equivalent amount of 5 ml to precipitate and mix well, add 5 ml of 10% tin chloride solution, reduce to 100 ml with water to reduce iron thiocyanate, and form a complex compound of molybdenum thiocyanate. Form. After leaving for 20 minutes, the molybdate amount can be determined by comparing the degree of color development of the solution with a standard solution prepared in advance.

The preparation of the standard solution for calibration of the present invention was carried out by using 0.1 m of both benzotriazole and molybdate.
g ~ 100 mg was collected in a 100 ml volumetric flask,
Dilute with water to operate the benzotriazole and molybdate in accordance with the above to develop color, and use them as standard solutions for calibration at each concentration. It is also possible to prepare a comparison table summarizing the degree of color development at each concentration of the inhibitor other than the standard solution, and compare the degree of color development of the table and the sample solution to obtain the inhibitor concentration.

Table 5 shows the results of a comparative test for checking the measurement accuracy of the analytical method according to the present invention. A test solution was prepared by adding a fixed amount of each of benzotriazole and sodium molybdate to 1000 ml of cooling water. It was measured by the analytical method. The measured values of benzotriazole and sodium molybdate are both within ± 10% of the added amount, and the evaluation method of the present invention is effective as a method for measuring benzotriazole and molybdate inhibitor concentrations in cooling water in a cooling device. It turns out that

[0043]

[Table 5]

As a result of measuring the time variation of the inhibitor concentration in water cooling of a closed circulation type computer, sodium molybdate decreased by 25 ppm in the initial 1000 hours and benzotriazole decreased by 25 ppm in the initial period of about 500 hours.
After that, both gradually decreased, and one year later, the former was about 25pp
It was found that m and the latter decreased by about 45 ppm. From this, the amount consumed in the early stage of operation and the amount consumed after a total of one year after that are obtained in advance, and the amount consumed rapidly in the initial stage of the entire system is sealed during operation so that it remains after one year. The inhibitor is added to the pure water by the cooling system in the circulation system. Then, the amount of the remaining inhibitor is measured by measuring each inhibitor concentration described above at the time of maintenance one year later. The remaining amount is added at the time of operation so that it becomes more than half of the amount consumed at the beginning of the above operation. More preferably, an amount equal to or more than that is left. If the amount of the inhibitor is excessively large, the cooling efficiency is lowered, which is not preferable, and it is preferably 1.5 times or less the amount consumed in the initial stage of the operation. The next time the remaining amount of the inhibitor is measured one year later, the remaining amount is inspected once a year thereafter. The cooling water temperature was 20 to 40 ° C. and the flow rate was 1 to 2 m / sec.

In this embodiment, the cooling water to which a mixed inhibitor of benzotriazole and molybdate is added as the inhibitor at a predetermined concentration is sent to the cooling section 3 by the pump 2 to cool the LSI module. And
An outlet 9 is provided in the cooling water circulation system, cooling water is taken out if necessary, and the inhibitor concentration is measured by the above method. If the inhibitor concentration is insufficient to suppress the corrosion of the equipment, the cooling water is used. Input port 30 provided in the tank 4
If the inhibitor concentration is too high, and if the inhibitor concentration is too high and adversely affects other equipment, the cooling water will be replenished in the same way. To maintain.

FIG. 8 shows BTA, molybdate and BTA.
The results of measuring the respective absorption curves by the absorptiometric method of white light in the case of mixing and molybdate are shown. In each case, the concentration was 10 ppm. From the figure, the absorption curve in the case of mixing is at the position where the absorption curves of BTA and molybdate are added at any wavelength. Therefore, in the case of mixing, the concentration of each corrosion inhibitor can be estimated by subtracting each absorption curve from the absorption curve. That is, the wavelength 270n
The absorption peak of m indicates the concentration of BTA regardless of the molybdate concentration, and the absorbance composition at the wavelength of 220 nm is the absolute value of 1/7 of the absorbance of BTA obtained from the absorbance of molybdate and the absorption peak at 270 nm. Consistency of the values can be used to estimate the concentration of molybdate and the concentration of BTA from the absorbance at two wavelengths.

As described above, according to the present invention, the corrosion inhibitor concentration can be easily controlled by measuring the white light absorption characteristics of the corrosion inhibitor and comparing the measured absorbance values at the respective wavelengths.

[0048]

According to the anticorrosion method and operation method of the electronic computer of the present invention, the number of maintenances can be reduced, the inorganic and organic mixed corrosion inhibitors are present in the cooling liquid, and the corrosion in the cooling liquid is further increased. It is possible to grasp the status of the inhibitor concentration, detect the amount of consumption, and periodically adjust the corrosion inhibitor, so it is possible to prevent problems such as leakage of coolant due to corrosion of the cooling device in advance. Therefore, extremely high reliability can be obtained. In particular, the mixed corrosion inhibitor of the present invention shows excellent corrosion resistance to iron-based, copper-based metals and systems in which they coexist, and further, the corrosion inhibitor has a metal having an anticorrosion property as an electrode, and its corrosion resistance and solution. The concentration of the corrosion inhibitor can be easily controlled by measuring the resistance.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a computer cooling device of the present invention.

FIG. 2 is a perspective view showing a partially cut surface showing a cooling structure of a semiconductor module.

FIG. 3 is a perspective view showing a mounting structure of an electronic computer.

FIG. 4 is a diagram showing the relationship between the amount of corrosion of copper and the amount of BTA.

FIG. 5 is a diagram showing the relationship between the corrosion rate of SUS304 and the inhibitor concentration.

FIG. 6 is a diagram showing the relationship between the corrosion rate of copper and the inhibitor concentration.

FIG. 7 is a diagram showing the relationship between inhibitor concentration and resistance value.

FIG. 8 is a diagram showing the relationship between absorbance and wavelength.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cooling water, 2 ... Pump, 3 ... Cooling part, 4 ... Cooling water tank, 5 ... Cooler, 6 ... Refrigerator, 7 ... Heat exchanger, 8 ... Flow control device, 11 ... Heat conduction disk, 13 ... Multilayer circuit board, 16 ... Semiconductor element, 19 ... Metal housing, 24
… Semiconductor module, 25… Multilayer printed circuit board.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location H05K 7/20 H05K 7/20 N (72) Inventor Kenichi Kasai 1 Horiyamashita, Hadano City, Kanagawa Stock Company General Manager Computer Division, Hiritsu Manufacturing Co., Ltd. (72) Ryo Hiraga 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd.

Claims (9)

[Claims] 1. A corrosion prevention method for a computer, wherein a semiconductor module is operated while being cooled by cooling water in a closed circulation system, wherein the cooling water contains a corrosion inhibitor, and the corrosion inhibitor is used for at least one year during the operation. An anticorrosion method for a computer, comprising: an amount consumed in the operation and an amount remaining. 2. A method of operating an electronic computer, wherein a semiconductor module is operated while being cooled by cooling water in a closed circulation system, wherein the cooling water contains a corrosion inhibitor, and the corrosion inhibitor is used for at least one year during the operation. There is an amount consumed and a remaining amount in the operation, the remaining amount of the corrosion inhibitor is measured at least at a desired time after the one year, and the remaining corrosion inhibition after the next desired operation. A method for operating an electronic computer, which comprises adjusting the content of an agent. 3. The method according to claim 2, wherein a predetermined amount of the cooling water is sampled, and a predetermined amount of an excessive amount of metal ions is added to the collected cooling water to precipitate the corrosion inhibitor. , A method of operating an electronic computer in which a complex compound is produced from a solution containing unreacted metal ions to cause color development, and the degree of color development is compared with a standard solution of known concentration. 4. The method according to claim 2 or 3, wherein a certain amount of cooling water containing benzotriazole as the corrosion inhibitor is sampled, and an excessive amount of copper ions is added to the sampled cooling water. A predetermined amount is added to precipitate all of the benzotriazole, and a solution containing unreacted copper ions is made alkaline to form a copper-benzotriazole complex to cause color development, and the degree of color development is compared with a standard solution of known concentration. A method of operating an electronic computer for measuring the concentration of the corrosion inhibitor. 5. The method according to claim 2 or 3, wherein a certain amount of cooling water containing an inorganic molybdate as the corrosion inhibitor is sampled, and the collected cooling water is excessive with respect to the molybdate. A predetermined amount of iron ion is added to precipitate all of the molybdate, and a solution containing unreacted iron ion is reduced to form a complex compound for color development, and the degree of color development is compared with a standard solution of known concentration. A method of operating an electronic computer, which compares and measures the concentration of the corrosion inhibitor. 6. The method according to claim 5, wherein a predetermined amount of iron thiocyanate solution containing an excess amount of iron ions is added to the molybdate to precipitate the molybdate, and then a tin chloride solution is added to cause unreacted reaction. A method of operating an electronic computer for reducing a solution containing iron ions to form a complex compound of molybdenum thiocyanate to develop color. 7. The method of operating an electronic computer according to claim 3, wherein the complex compound is filtered and then filtered, and the concentration of the corrosion inhibitor is measured by the degree of color development of the filtrate. 8. A method for preventing corrosion of a computer, wherein a semiconductor module is operated while being cooled by cooling water in a closed circulation system, wherein the cooling water contains a corrosion inhibitor, and the corrosion inhibitor is used for at least one year during the operation. An anticorrosion method for a computer, comprising: an amount consumed in the operation and an amount in which at least one half of the amount consumed in an initial reaction of the operation remains after the operation for at least one year. 9. A method of operating an electronic computer, wherein a semiconductor module is operated while being cooled by cooling water in a closed circulation system, wherein the cooling water contains a corrosion inhibitor, and the corrosion inhibitor is used for at least one year during the operation. The amount consumed in the operation and the amount remaining at least half the amount consumed in the initial reaction of the operation after the operation for at least one year, and at least at a desired time after the one year. A method for operating an electronic computer, comprising: measuring the remaining amount of the corrosion inhibitor and adjusting the content of the remaining corrosion inhibitor after the next desired operation.