JP6279950B2 - Heat exchange member - Google Patents

Description

  The present invention relates to a heat exchange member used for heat exchange with a fluid.

  In semiconductor manufacturing apparatuses, liquid crystal manufacturing apparatuses, and the like, heat exchange members are used to adjust the temperature by contacting with a high-temperature or low-temperature fluid or to dissipate heat received from a heat source. An alumina sintered body is used as such a heat exchange member (see Patent Document 1).

Japanese Patent No. 4762168

  Since the alumina sintered body is a polycrystalline body and is composed of a plurality of particles, the particles fall off due to repeated contact between the heat exchange member made of the alumina sintered body and the fluid (hereinafter, In some cases, it may be referred to as “granulation.” In this case, for example, a product such as a semiconductor wafer or liquid crystal glass is contaminated. In addition, when the dropped particles flow with the fluid, the particles enter a facility such as a pump for circulating the fluid, causing the facility to malfunction. Therefore, a heat exchange member made of an alumina sintered body is required to have less degranulation even when contact with a fluid is repeated. Further, this heat exchange member is required to further improve heat exchange efficiency.

  The present invention has been devised to satisfy the above-described requirements, and provides a heat exchange member with improved heat exchange efficiency and improved reliability with less degranulation that causes product contamination and equipment failure. To do.

  The heat exchange member of the present invention is a heat exchange member made of an alumina sintered body and used for heat exchange with a fluid, and has a kurtosis (Rku) of 3 determined from a roughness curve on a contact surface with the fluid. And 9 or less.

  According to the heat exchange member of the present invention, since the flow of fluid is smooth and there are few degranulations causing product contamination and equipment failure, the heat exchange member has improved heat exchange efficiency and reliability. be able to.

It is a perspective view which shows an example of the heat exchange member of this embodiment. It is a perspective view including the partial cross section cut | disconnected in the direction orthogonal to the flow direction of the fluid which shows the other example of the heat exchange member of this embodiment.

  FIG. 1 is a perspective view showing an example of the heat exchange member of the present embodiment. In the following drawings, the same reference numerals are assigned to the same components. The heat exchange member 10 of the example shown in FIG. 1 has a main surface 1 and has a plurality of fins 2 on the opposite side of the main surface 1.

  Between the adjacent fins 2 is a fluid flow path 3, and the surface of the fin 2 and the surface sandwiched between the fins 2 are contact surfaces with the fluid. The temperature of the member placed on the main surface 1 can be adjusted, or the heat transmitted from the member placed on the main surface 1 can be radiated. The fluid may be a gas or a liquid.

  The heat exchange member 10 of the present embodiment is made of an alumina sintered body, and the kurtosis (Rku) obtained from the roughness curve on the contact surface with the fluid is more than 3 and 9 or less. Here, the kurtosis (Rku) obtained from the roughness curve is a parameter indicating the kurtosis of the surface, the unevenness of the contact surface in the present embodiment. To put it flatly, in the heat exchange member 10 of the present embodiment. The contact surface is a pointed alumina crystal that becomes a peak.

  Since the heat exchange member 10 of the present embodiment satisfies the above-described configuration, the alumina crystals that come into contact with the fluid are sharp, so that the fluid is less likely to be laminar on the contact surface, and the fluid flow is smooth. Therefore, the heat exchange efficiency is improved. In addition, since the fluid flow is smooth, even if the contact with the fluid is repeated, it is difficult to shed, and the factor of product contamination and equipment failure is reduced, so that the reliability is improved. In addition, it is guessed that it is difficult to degranulate because the part where the alumina crystal is not exposed is also sharp. Moreover, the dust etc. which are floating in the fluid can also be collected by satisfy | filling the said structure.

  The kurtosis (Rku) obtained from the roughness curve on the contact surface with the fluid is preferably 4 or more and 9 or less. When such a configuration is satisfied, the flow of the fluid becomes smoother. Therefore, even if the contact with the fluid is repeated, it becomes difficult for the particles to fall. In addition, since the factors of product contamination and equipment failure are further reduced, the reliability is further improved. In particular, the kurtosis (Rku) determined from the roughness curve is preferably 4 or more and 9 or less on the surface having a large contact area with the fluid.

  Here, as a method for confirming kurtosis (Rku) obtained from the roughness curve on the contact surface, it may be measured using a contact type or non-contact type roughness measuring instrument based on JIS B 0601-2001.

  Further, since the heat exchange member 10 of the present embodiment is made of an alumina sintered body, it is used even if the fluid has corrosivity or the environment used is a corrosive gas environment. Is possible.

  Next, FIG. 2 is a perspective view including a partial cross section cut in a direction orthogonal to the fluid flow direction, showing another example of the heat exchange member of the present embodiment. The heat exchange member 20 in the example shown in FIG. 2 has a top plate 4, a partition wall 5, a bottom plate 6, a fluid inlet 7 and an outlet not shown. The space surrounded by the top plate 4, the partition wall 5 and the bottom plate 6 is the flow path 3, and the fluid entering from the inflow port 7 branches into each flow path 3 and is discharged from the outflow port. is there.

  And in the heat exchange member 20, each surface which forms the flow path 3 is a contact surface, The temperature adjustment of the member mounted in the main surface 1 is made by contacting a fluid of high temperature and low temperature with this contact surface. Or the heat transmitted from the member placed on the main surface 1 can be dissipated.

The heat exchange member 20 of the present embodiment is made of an alumina sintered body like the heat exchange member 10 shown in FIG. 1, and the kurtosis (Rku) obtained from the roughness curve at the contact surface with the fluid exceeds 3. 9 or less. By satisfying such a configuration, it becomes difficult for the fluid to become a laminar flow on the contact surface, and the fluid flow is smooth, so that the heat exchange efficiency is improved, resulting in product contamination and equipment failure. Reliability is improved because there is little shedding.

  In the heat exchange members 10 and 20 of the present embodiment, it is preferable that the average crystal grain size of alumina crystals observed on the mirror-finished contact surface is 1 μm or more and 2 μm or less. When such a configuration is satisfied, the falling off of alumina crystals can be reduced without increasing the production cost by finely pulverizing the raw material.

Here, as a method for measuring the average crystal grain size of the alumina crystal observed on the mirror-finished contact surface of the heat exchange members 10 and 20 of the present embodiment, first, the contact surface is mirror-finished from the firing temperature. Fire etching is performed at a temperature range of 50-100 ° C. Then, it was photographed with a scanning electron microscope (SEM JEOL JSM-7001F, etc.) at a magnification of 1000 to 3000 times, and the photographed image was obtained by using an image analyzer (for example, Win ROOF made by Mitani Corp.) And the average crystal grain size may be determined by calculating the equivalent circle diameter of each crystal from the area.

  In the heat exchange members 10 and 20 of the present embodiment, the alumina sintered body includes silica (silicon oxide), and the silica content in the surface portion of the contact surface is within the alumina sintered body. It is preferable that the content is larger than the content of silica.

  Thus, when the content of silica in the surface portion of the contact surface of the alumina sintered body is larger than the content of silica in the alumina sintered body, the alumina crystals are more difficult to fall off and are manufactured. Since the factors of object contamination and equipment failure are further reduced, the heat exchange members 10 and 20 are further improved in reliability. The surface portion of the contact surface is a range from this surface to 50 μm in the depth direction perpendicular to the surface of the contact surface, and the inside of the alumina sintered body exceeds 50 μm from the surface, It is the range from the other surface to 50 μm.

  Moreover, the heat exchange member 20 of this embodiment is provided with the flow path 3 on the inner side, and it is preferable that the silica content in the surface portion of the exposed surface is smaller than the silica content in the interior. When such a configuration is satisfied, the exposed surface is improved in corrosion resistance, so that it is useful in a corrosive environment, and the temperature of the member placed on the main surface 1 in the corrosive environment. Adjustment can be performed, and heat transmitted from a member placed on the main surface 1 can be radiated. The surface portion of the exposed surface is a range from this surface to 50 μm in the depth direction perpendicular to the surface of the exposed surface. In FIG. 2, the main surface 1, the other surface, the side surface, and the like of the main surface 1 correspond to the exposed surface.

  Then, the comparison between the content of silica in the surface portion of the contact surface and the content of silica in the interior, and the comparison between the content of silica in the surface portion of the exposed surface and the content of silica in the interior are as follows. , 20 The cross section perpendicular to the surface of the contact surface or the exposed surface is taken as the measurement surface, and the surface portion and the inside of the contact surface, and the surface portion and the inside of the exposed surface by an energy dispersive X-ray analyzer (EDS) attached to the SEM What is necessary is just to judge by the content difference of Si. Further, a cross section perpendicular to the contact surface or exposed surface of the heat exchange members 10 and 20 may be used as a measurement surface, and determination may be made based on the color difference of Si color mapping using an electron beam microanalyzer (EPMA).

  Next, an example of a method for producing the heat exchange member of the present embodiment will be described.

  First, alumina powder having a particle size of about 5 μm is prepared, and this alumina powder is heat-treated at a temperature of about 1400 ° C. And the alumina powder after heat processing is put into a mill with an alumina ball | bowl, and it grind | pulverizes until a particle size will be set to about 1 micrometer. Thus, the alumina powder which consists of a pointed particle can be obtained by grind | pulverizing after heat processing. Hereinafter, it will be described as pulverized alumina powder for identification.

In addition, a sintering aid powder such as silica, calcia (calcium oxide), magnesia (magnesium oxide) is prepared, and the sintering aid powder of 100% by mass of the pulverized alumina powder and the sintering aid powder is used. The amount is adjusted to 7% by mass or less, and the balance is crushed alumina powder. This is the starting material.

  Then, the starting material, water, and alumina balls are put in a mill and mixed, and further a molding binder such as polyvinyl alcohol, polyethylene glycol, and acrylic resin is added and mixed to obtain a slurry. The amount of the molding binder added may be, for example, 4 parts by mass or more and 8 parts by mass or less with respect to 100 parts by mass of the starting material.

  Next, the granulated granule is obtained by spray-drying the obtained slurry using a spray dryer. Then, the obtained granules are put into a rubber mold and molded by a hydrostatic press method (rubber press method) to obtain a block-shaped molded body.

  Next, the obtained molded body is cut so as to have a predetermined shape. At this time, in order to obtain the heat exchange member 10 having the shape shown in FIG. 1, the outer shape may be cut so that a plurality of fins 2 are provided. Moreover, what is necessary is just to cut so that it may become the predetermined shape of the top plate 4, the partition 5, and the baseplate 6 in order to obtain the heat exchange member 20 shown in FIG. In addition, since it is only necessary to obtain the final product shape by grinding after firing, it is not necessary to have the same shape as the final product at the time of cutting.

  Next, after drying the obtained molded body, it is placed in a firing furnace and fired at a maximum temperature of 1450 ° C. or higher and 1600 ° C. or lower. The firing time may be set according to the size of the molded body. And the heat exchange member 10 shown in FIG. 1 can be obtained by performing a grinding process as needed. In addition, with respect to the heat exchange member 20 shown in FIG. 2, when the molded bodies to be the top plate 4, the partition walls 5, and the bottom plate 6 are individually fired, processing or grinding for forming the inlet 7 and the outlet after firing. 2 is performed, and the heat exchange member 20 shown in FIG. 2 can be obtained by bonding using an adhesive. Moreover, after obtaining the molded object used as the top plate 4, the partition 5, and the baseplate 6 by cutting, the slurry mentioned above is apply | coated to a joining surface, and it heats, and also obtains the heat exchange member 20 shown in FIG. be able to.

  Further, as another method for obtaining a molded body, first, a predetermined amount of pulverized alumina powder, sintering aid powder, molding binder, dispersant, lubricant and solvent are weighed, and stirred and mixed for a predetermined time with a stirring mixer. These are mixed and further kneaded for a predetermined time with a kneader kneader to obtain a clay. Next, the obtained clay is put into an extrusion molding machine, and a molded body that becomes the heat exchange member 10 having the shape shown in FIG. 1, the top plate 4, the partition wall 5, and the bottom plate constituting the heat exchange member 20 shown in FIG. The molded body may be obtained by passing through a mold capable of obtaining a plate-shaped molded body of 6.

  Furthermore, as another method for obtaining a molded body, a green sheet formed by a doctor blade method using a slurry or a green sheet formed by a roll compaction method using granules is processed into a desired shape by laser processing or a mold. The molded body may be formed by laminating later. Specifically, in the case of the heat exchange member 20 shown in FIG. 2, the top plate 4 and the bottom plate 6 are punched out by laser processing or a mold so that only the outer shape becomes a desired shape, and the portion that becomes the partition wall 5 is It is only necessary to laminate after punching with laser processing or a mold so that the outer shape and the hole have a desired shape so that the portion to become the flow path 3 becomes a hole.

  Moreover, what is necessary is just to use the slurry mentioned above as a bonding agent, for example to a joining surface, and after lamination | stacking, it is suitable to apply a pressure of about 0.5 MPa through a flat plate-shaped pressurizing tool.

Moreover, in order to make the average crystal grain size of the alumina crystal observed on the contact surface with the fluid 1 μm or more and 2 μm or less, the maximum temperature is 1450 ° C. or more and 1500 ° C. or less, and the holding time is 2.5 hours or more 5
It may be less than time.

  In order to make the silica content in the surface portion of the contact surface of the alumina sintered body larger than the silica content in the alumina sintered body, silica is used as the sintering aid powder. The entire contact portion, in other words, the flow path 3 may be covered with a common material having one vent opening and fired. Thus, by firing in a relatively closed space, the silica content in the surface portion can be increased more than the silica content in the alumina sintered body.

  If it is a shape like the heat exchange member 20 shown in FIG. 2, it is fired in the state of the final product by bonding or joining at the stage of the molded body, leaving only the inlet 7 or the outlet, What is necessary is just to perform the process which forms the inflow port 7 or the outflow port which was not formed at the time of shaping | molding after baking.

  Alternatively, a molded body using silica as a sintering aid powder may be subjected to vacuum firing, so that the silica contained in the molded body may be softened and raised to the surface portion of the entire alumina sintered body. Further, in the heat exchange member 20 having the flow path 3 as shown in FIG. 2, if the exposed surface is polished after firing by such a method, the silica content in the surface portion of the exposed surface is reduced to alumina. The content of silica in the sintered compact can be reduced.

  Furthermore, as another manufacturing method, in the lamination, a green sheet with a large amount of silica added to the surface portion of the contact surface is used, or a green sheet with a small amount of silica added to the surface portion of the exposed surface. May be used.

  The heat exchange members 10 and 20 of the present embodiment obtained by the above method have excellent heat exchange efficiency because the fluid flow is smooth, which causes contamination of products and equipment failure. It has excellent reliability due to less degranulation.

10, 20: heat exchange member 1: main surface 2: fins 3: flow path 4: top plate 5: partition wall 6: bottom plate 7: inlet

Claims (5)

  It is a heat exchange member made of an alumina sintered body and used for heat exchange with a fluid, and the kurtosis (Rku) obtained from the roughness curve at the contact surface with the fluid is more than 3 and 9 or less. A heat exchange member characterized by the above. The heat exchange member according to claim 1, wherein a kurtosis (Rku) obtained from a roughness curve on the contact surface is 4 or more and 9 or less.   3. The heat exchange member according to claim 1, wherein an average crystal grain size of alumina crystals observed on a mirror-finished surface of the contact surface is 1 μm or more and 2 μm or less.   The alumina sintered body contains silica, and the silica content in the surface portion of the contact surface is larger than the silica content in the alumina sintered body. The heat exchange member according to claim 3.   The alumina sintered body contains silica and has a flow path inside, and the silica content in the surface portion of the exposed surface is less than the silica content in the alumina sintered body. The heat exchange member according to claim 1, wherein the heat exchange member is a heat exchange member.

Images