JP7457760B2 - heat transfer plate - Google Patents

Description

The present disclosure relates to heat exchanger plates.

Conventionally, the technology described in Patent Document 1 is known as a heat exchanger plate. The heat transfer plate described in Patent Document 1 includes a heat transfer medium flow path through which a heat transfer medium flows through an aluminum or aluminum alloy base member (metal base member), and a bonding aluminum or aluminum alloy member (for bonding) from above the heat transfer medium flow path. It has a structure in which metal parts) are sealed by forging pressure welding. This heat transfer plate can be used as a heat transfer plate for various flat panel display (FPD) manufacturing equipment such as liquid crystal manufacturing equipment and semiconductor manufacturing equipment.

Patent No. 6948832

Regarding the heat transfer plate disclosed in Patent Document 1, it is desirable to increase the bonding strength between the metal base member and the bonding metal member to further improve the airtightness of the internal space. Further, it is desirable to further improve the heat conductivity of the heat exchanger plate.

The present disclosure is a technology completed based on the above circumstances, and one of the objects is to provide a heat exchanger plate that can improve bonding strength. Another object of the present invention is to provide a heat exchanger plate that can improve heat conductivity.

The present disclosure has a first groove and a second groove recessed from the first groove, and includes a base material made of metal, and a fitting member made of metal that fits into the first groove, The first groove part is provided with a pair of first side surfaces that fall from the surface of the base material and are opposite to each other, and the second groove part has a bottom surface that forms the bottom of the second groove part and a bottom surface that rises from the bottom surface and that are opposite to each other. a pair of opposing second side surfaces, the distance between the pair of second side surfaces is smaller than the distance between the pair of first side surfaces, and the pair of second side surfaces is one of the second side surfaces. is a heat exchanger plate that bulges toward the other second side surface, and the opposing surface of the fitting member that faces the bottom surface is a heat exchanger plate that bulges toward the bottom surface side.

According to such a heat transfer plate, the surface area of the internal space (the flow path through which the heat transfer medium flows) surrounded by the opposing surface, the pair of second side surfaces, and the bottom surface is reduced by the second side surface and the opposing surface not protruding. It can be made larger than the case. Thereby, the contact area with the heat transfer medium can be increased and the heat transfer properties of the heat transfer plate can be improved. Furthermore, if the fitting member is pressurized and fitted to the first groove so that the second side surface or the opposing surface bulges, an oxide film is formed due to friction at the contact portion between the fitting member and the first groove. Even when peeled off, the abutting portions can be metallurgically bonded to increase the bonding strength even at temperatures below the melting point of the metal. Thereby, the airtightness of the internal space of the heat exchanger plate can be improved.

In the above configuration, the opposing surface includes an opposing end that is an end on the second side surface side, and an opposing proximal portion that is closest to the bottom surface, and the distance between the opposing end and the bottom surface is A is ₁ , and when the distance between the opposing proximal portion and the bottom surface is A ₂ , the first bulge ratio R ₁ (%) that satisfies the following formula (1) is 0.3% or more. Good too.
R ₁ (%) = {(A ₁ - A ₂ )/2A ₂ }×100...Formula (1)

Further, in the above configuration, the pair of second side surfaces include a pair of side surface end portions that are ends on the bottom surface side or the opposing surface side, and a pair of side surface adjacent portions that are closest to each other, When the distance between the side edges of is _B1 , and the distance between the pair of adjacent side surfaces is _B2 , the second bulge ratio R2 (%) that satisfies the following formula ( ₂ ) is 0.5 % or more.
R ₂ (%) = {(B ₁ - B ₂ )/2B ₂ }×100...Formula (2)

With this configuration, the heat transfer plate can be made such that the fitting member and the first groove portion are joined to an extent that the airtightness of the internal space of the heat transfer plate can be suitably maintained.

According to the present disclosure, it is possible to provide a heat exchanger plate that can improve bonding strength. Moreover, it becomes possible to provide a heat exchanger plate that can improve heat conductivity.

A diagram of the heat exchanger plate according to Embodiment 1 viewed from the front side. Cross-sectional view of the heat transfer plate (cross-section of line II-II in FIG. 1) FIG. 11 is a cross-sectional view showing a state in which a fitting member is inserted into a groove of a base material. Cross-sectional view of a heat exchanger plate according to Embodiment 2

<Embodiment 1>
Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 3. In this embodiment, when manufacturing a liquid crystal panel display (LCD) or an organic EL display (OLED), the temperature of the substrate glass is controlled in the process of forming various thin films such as electrode films and coating films on the substrate glass. The heat exchanger plate 100 used for this purpose will be explained. In such a heat exchanger plate 100, from the viewpoint of ensuring temperature uniformity of the substrate glass, the width of the surface 1A of the base material 1 is sized to match the substrate glass.

As shown in FIGS. 1 and 2, the heat transfer plate 100 includes a plate-shaped base material 1 having a groove 2 having a predetermined shape on the surface 1A side, and a surface 1A of the base material 1 with respect to the groove 2. A fitting member 3 fitted from the side is provided. Metal is used as the material for the base material 1 and the fitting member 3. From the viewpoint of improving heat conductivity, this metal is preferably an aluminum alloy, and more preferably an aluminum alloy such as JIS 1050, 1100, 3003, 3004, 5052, 5005, 6061, 6063, 7003, 7N01 or the like.

As shown in FIG. 1, the groove portion 2 has a plurality of linearly extending portions and curved portions connected in the plane direction of the surface 1A between one end 2A and the other end 2B, forming one stream as a whole. forming a road. As shown in FIG. 2, the groove 2 includes a first groove 10 that is recessed from the front surface 1A of the base material 1 to the back surface 1B side (in the thickness direction of the base material 1), and a A second groove portion 20 recessed in the horizontal direction is provided. The fitting member 3 has an outer shape along the groove 2 in the surface direction of the surface 1A, and fits into the first groove 10.

The first groove portion 10 includes a pair of first side surfaces 11, 11 that fall from the surface 1A of the substrate 1 in the thickness direction and face each other, and a pair of first bottom surfaces 12, 12 that rise from the pair of first side surfaces 11, 11 and extend in the plate surface direction of the substrate 1 and form the bottom of the first groove portion 10. The second groove portion 20 includes a second bottom surface 22 that forms the bottom of the second groove portion 20, and a pair of second side surfaces 21, 21 that rise from the second bottom surface 22 toward the first groove portion 10 and extend to the pair of first bottom surfaces 12, 12 and face each other. The distance B ₁ (or B2 or B3) between the pair of second side surfaces 21, 21 is smaller than the distance L between the pair of first side surfaces 11, 11.

The pair of first side surfaces 11, 11 and the pair of first bottom surfaces 12, 12 abut against the fitting member 3 fitted into the groove portion 2. The fitting member 3 has a rectangular shape in cross section, and its thickness is approximately equal to the depth of the first groove portion 10 (the length in the thickness direction of the first side surface 11), and its length in the plate surface direction is approximately equal to the distance L between the pair of first side surfaces 11, 11.

The space surrounded by the second bottom surface 22, the pair of second side surfaces 21, 21, and the opposing surface 31 facing the second bottom surface 22 in the fitting member 3 is defined as an internal space S. The internal space S is a flow path through which a heat transfer medium such as oil passes. As shown in FIG. 1, the heat transfer medium flows from one end 2A of the groove 2 through the internal space S to the other end 2B of the groove 2. The heat exchanger plate 100 in this embodiment is used in a high vacuum environment in a vacuum apparatus in the above-mentioned film forming process for LCDs, etc., so the base material 1 and the fitting member 3 are removed from the internal space S shown in FIG. Airtightness is required to prevent gas or liquid from leaking through the contact area. The portions where the base material 1 and the fitting member 3 are in contact with each other are joined by, for example, a forge welding process that will be described later.

The opposing surface 31 of the fitting member 3 bulges toward the second bottom surface 22 side. The second bottom surface 22 does not bulge toward the opposing surface 31 and is a horizontal surface (or does not bulge out more than the opposing surface 31). The opposing surface 31 includes opposing ends 31A1 and 31A3 that are the ends on the side of the pair of second side surfaces 21 and 21, and a central portion of the opposing surface 31 in the plate surface direction that is closest to the second bottom surface 22. A facing proximal portion 31A2 is provided. When the distance between the left opposing end 31A1 and the second bottom surface 22 is _A1 , and the distance between the opposing proximal portion 31A2 and the second bottom surface 22 is _A2 , the following formula (1) is satisfied. The first swelling ratio R ₁ (%) is 0.3% or more.
R ₁ (%) = {(A ₁ - A ₂ )/2A ₂ }×100...Formula (1)
Note that the first bulge ratio _R1 can be obtained by replacing _A1 in the above formula (1) with _A3 , assuming that the distance between the right opposing end 31A3 and the second bottom surface 22 is _A3 . It may be a value that is

The first bulge ratio _R1 may be 0.4% or more, 0.5% or more, 25% or less, 10% or less, 5% or less, 1% It may be less than or equal to 0.8%. According to such a range, the base material 1 and the fitting member 3 become the heat transfer plate 100 suitably joined, and the heat transfer medium can be effectively flowed into the internal space S while improving the heat transfer property. This becomes a hot plate 100.

In the pair of second side surfaces 21, 21, the left side (one) second side surface 21 in the figure bulges out toward the right side (other) second side surface 21 side. Similarly, in the pair of second side surfaces 21, 21, the second side surface 21 on the right side in the figure bulges out toward the second side surface 21 on the left side. The pair of second side surfaces 21, 21 are the pair of side surface ends 21B1, 21B1 which are the ends on the opposing surface 31 side, and the central portions in the thickness direction of the pair of second side surfaces 21, 21, which are the most mutually It includes a pair of side surface proximal portions 21B2, 21B2 which are adjacent portions, and a pair of side surface end portions 21B3, 21B3 which are end portions on the second bottom surface 22 side. When the distance between the upper pair of side surface ends 21B1 and 21B1 is _B1 , and the distance between the pair of side surface proximal portions 21B2 and 21B2 is _B2 , the second bulge ratio R that satisfies the following formula (2) ₂ (%) is 0.5% or more.
R ₂ (%) = {(B ₁ - B ₂ )/2B ₂ }×100...Formula (2)
The second bulge ratio _R2 is the value obtained by replacing _B1 in the above formula (2) with _B3 , assuming that the distance between the pair of lower side edges 21B3 and 21B3 is _B3 . You can also use it as

The second swelling ratio _R2 may be 0.55% or more, 0.6% or more, 0.65% or more, 25% or less, 10% or less, It may be 5% or less, 1% or less, or 0.7% or less. According to such a range, the base material 1 and the fitting member 3 become the heat transfer plate 100 suitably joined, and the heat transfer medium can be effectively flowed into the internal space S while improving the heat transfer property. This becomes a hot plate 100.

Next, a method for manufacturing the heat exchanger plate 100 will be described. The manufacturing method of the heat exchanger plate 100 includes a groove forming step in which the grooves 2 are formed in the base material 1 by cutting or the like, and a forge welding step in which the base material 1 and the fitting member 3 are heated at a predetermined temperature and pressed at a predetermined pressure to join them. and, including.

As shown in FIG. 3, in the forge welding process, the fitting member 3 is inserted into the first groove 10. At this time, the opposing surface 31 of the fitting member 3 and the pair of second side surfaces 21, 21 in the second groove 20 are not bulged, and for example, the opposing surface 31 is along a horizontal plane, and the pair of second side surfaces 21, 21 are not bulged. , 21 are along the vertical plane.

Then, with the pair of first side surfaces 11, 11 (or the pair of first side surfaces 11, 11 and the pair of first bottom surfaces 12, 12) in contact with the fitting member 3, the base material 1 and the fitting member 3 is heated, and then (or at the same time as heating), the fitting member 3 is pressed against the base material 1 and pressurized (this is called forge welding). The heating temperature at this time may be below the melting point of the metals constituting the base material 1 and the fitting member 3, may be 250 degrees or more and 500 degrees or less, 300 degrees or more and 450 degrees or less, or 350 degrees or more and 420 degrees or less. But that's fine. Further, the pressure with which the fitting member 3 is pushed is set to a pressure that allows the fitting member 3 to undergo plastic deformation in the first groove portion 10 (pressure that is higher than hot deformation resistance). According to such a range, the oxide film is destroyed by friction on the surface of the abutting part between the base material 1 and the fitting member 3, and a new aluminum surface is exposed on the surface, so that the abutting part can be metal-bonded. Can be done.

When the forge welding process is completed, as shown in FIG. 2, the fitting member 3 is fitted into the first groove 10 to obtain a heat exchanger plate 100 in which the opposing surface 31 and the pair of second side surfaces 21, 21 are bulged. be able to. Incidentally, by carrying out the manufacturing process of the heat exchanger plate 100 as described above, the rate at which the opposing surface 31 and the pair of second side surfaces 21, 21 bulge (the first bulging ratio R ₁ and the second bulging ratio R ₂ ) is determined. A base material in which the opposing surface and the pair of second side surfaces are pre-cut into a concave shape by the amount of the bulge in the groove forming step (the shape is obtained by subtracting the bulge); and By performing a forge welding process using the fitting member, the fitting member and the base material are metallurgically bonded and a rectangular inner space is formed, although the opposing surfaces and the pair of second side surfaces are not bulged. heat exchanger plates can be obtained.

Next, the effects of this embodiment will be explained. In this embodiment, it has a first groove part 10 and a second groove part 20 recessed from the first groove part 10, and a base material 1 made of metal and a fitting member 3 made of metal that fits into the first groove part 10. The first groove part 10 includes a pair of first side surfaces 11, 11 that fall from the surface of the base material 1 and face each other, and the second groove part 20 constitutes the bottom of the second groove part 20. It includes a second bottom surface 22 and a pair of second side surfaces 21, 21 rising from the second bottom surface 22 and facing each other, and the distance between the pair of second side surfaces 21, 21 is equal to the distance between the pair of first side surfaces 11, 11. In the pair of second side surfaces 21, 21, one second side surface bulges toward the other second side surface side, and faces the second bottom surface 22 in the fitting member 3. The opposing surface 31 showed the heat exchanger plate 100 bulging toward the second bottom surface 22 side.

According to such a heat transfer plate 100, the surface area of the internal space S (the flow path through which the heat transfer medium flows) surrounded by the opposing surface 31, the pair of second side surfaces 21, 21, and the second bottom surface 22 is It can be made larger than the case where the side surface and the opposing surface 31 are not bulged. Thereby, the contact area with the heat transfer medium can be increased and the heat transfer properties of the heat transfer plate 100 can be improved. Moreover, if the fitting member 3 is pressurized and fitted to the first groove 10 as the second side surface or the opposing surface 31 bulges out, the contact portion between the fitting member 3 and the first groove 10 will be The oxide film is peeled off by friction, and even at temperatures below the melting point of the metal, the abutting parts can be metallurgically bonded to increase the bonding strength. Thereby, the airtightness of the internal space of the heat exchanger plate 100 can be improved.

In the above configuration, the opposing surface 31 includes an opposing end 31A1 that is an end on the second side surface side, and an opposing proximal portion 31A2 that is closest to the second bottom surface 22, and the opposing end 31A1 and the second bottom surface 22 When the distance between the opposing proximal portion 31A2 and the second bottom surface 22 is _A2 , the first bulge ratio _R1 (%) that satisfies the following formula (1 ₎ is It may be 0.3% or more.
R ₁ (%) = {(A ₁ - A ₂ )/2A ₂ }×100...Formula (1)

In the above configuration, the pair of second side surfaces 21, 21 include a pair of side surface ends 21B1 which are ends on the second bottom surface 22 side or the opposing surface 31 side, and a pair of side surface proximal portions 21B2 which are closest to each other. , where the distance between the pair of side edge portions 21B1 is _B1 , and the distance between the pair of side surface proximal portions 21B2 is _B2 , a second bulge rate _R2 that satisfies the following formula (2) ( %) may be 0.5% or more.
R ₂ (%) = {(B ₁ - B ₂ )/2B ₂ }×100...Formula (2)

With this configuration, the heat transfer plate 100 can be formed in such a way that the fitting member 3 and the first groove portion 10 are joined to an extent that the airtightness of the internal space of the heat transfer plate 100 can be suitably maintained.

<Embodiment 2>
Next, a second embodiment of the present disclosure will be described with reference to Fig. 4. In this embodiment, the description of the structure, operation, and effects that overlap with those of the above embodiment will be omitted.

The heat transfer plate 200 comprises a substrate 201 having a groove 202 formed in a predetermined shape on the surface 201A side, and a fitting member 203 fitted into the groove 202 from the surface 201A side of the substrate 201. The groove 202 comprises a first groove 210 recessed from the surface 201A of the substrate 201 in the thickness direction of the substrate 201, and a second groove 220 recessed from the first groove 210 in the thickness direction of the substrate 201.

The first groove portion 210 is provided with a pair of first side surfaces 211, 211 that fall down in the thickness direction from the surface 201A of the base material 201, face each other, and are inclined so that they approach each other as they go downward. It has a tapered shape. The first groove portion 210 does not include the pair of first bottom surfaces 12, 12 shown in the first embodiment. The second groove portion 220 has a second bottom surface 222 forming the bottom of the second groove portion 220, and a second bottom surface 222 that rises from the second bottom surface 222 toward the first groove portion 210 side, extends to a pair of first side surfaces 211, 211, and faces each other. A pair of second side surfaces 221, 221. The fitting member 203 has an inverted trapezoidal shape (tapered shape) in cross section. The space surrounded by the second bottom surface 222, the pair of second side surfaces 221, 221, and the opposing surface 231 facing the second bottom surface 222 in the fitting member 203 is defined as an internal space S.

The opposing surface 231 of the fitting member 203 bulges toward the second bottom surface 222 side. In the pair of second side surfaces 221, 221, the second side surface 221 on the left side in the figure bulges out toward the second side surface 221 on the right side. Similarly, in the pair of second side surfaces 221, 221, the second side surface 221 on the right side in the figure bulges out toward the second side surface 221 on the left side.

The present technology will be described in detail below based on examples. Note that the present technology is not limited in any way by these examples.

[Manufacture of heat exchanger plates]
A first groove and a second groove were formed in a base material made of an aluminum alloy by cutting, and a fitting member made of an aluminum alloy was inserted into the first groove as shown in FIG. At this time, the lengths of the pair of second side surfaces in the thickness direction (vertical direction) are each 20 mm, and the lengths of the opposing surfaces and the bottom surface in the plate surface direction (horizontal direction) are each 20 mm. The cross-sectional area was 400 mm ² (the internal space was a square with sides of 20 mm). Next, while heating the base material and the fitting member to 400 degrees, the fitting member is pressurized with a load of 5000 tons to join (forge weld) the fitting member to the first groove, thereby forming the pair of second side surfaces. A heat exchanger plate having a bulged surface and a facing surface was manufactured.

[Measurement of each distance and calculation of bulge rate]
Regarding the obtained heat exchanger _plate , as _shown in FIG _. The distances B ₁ and B ₃ between the side edges and the distance B ₂ between the pair of side edges were each measured four times. The results of the four measurements are shown in Examples 1-1 to 1-4 in Table 1, respectively. In addition, the first bulge ratio R 1 and the second bulge ratio R ₂ were calculated for each example using the measurement results of each distance and equations ( ₁ ) and (2) described in Embodiment 1 above. . The results are shown in Table 1.

The larger of the measured values _A1 or A3 is regarded as _A1 in the above formula ( ₁ ) to calculate _R1 , and the larger of the measured values _B1 or _B3 is regarded as _B1 in the above formula (2) to calculate _R2 . For example, in Example 1-4, which is the result of the fourth measurement, _A3 is regarded as _A1 in the above formula ( ₁ ) to calculate R1, and _B3 is regarded as _B1 in the above formula (2) to calculate R2. Reference Example 1 also shows the average value of the four measurement results for each distance and _the swelling ratios _R1 and _R2 calculated based on the average value.

[Cross-sectional observation]
Partially cutting the heat transfer plate to expose a cross section (the cross section shown in FIG. 2) perpendicular to the direction in which the internal space formed by the base material and the fitting member extends (the direction in which the heat transfer medium flows); The cross section was visually observed. A state in which there was no gap in the contact portion between the base material and the fitting member was marked as "O", and a state in which there was a partial gap was marked as "x". The results are shown in Table 1.

[Leak test]
One end (2A in FIG. 1) of the flow path (internal space) through which the heat transfer medium passes in the heat transfer plate was blocked, and the other end (2B in FIG. 1) was connected to a helium leak detector. The internal space was then evacuated, and helium was sprayed onto the surface of the heat transfer plate to evaluate the presence or absence of helium leakage (vacuum spray method). Cases where there was no helium leakage were marked with "◯", and cases where there was a helium leak were marked with "X". The results are shown in Table 1.

<Comparative example 1>
A heat exchanger plate in which the opposing surface and the pair of second side surfaces were hardly visually bulged was manufactured using the same manufacturing method as in the above example. Regarding this heat exchanger plate, the distances A ₁ and A ₃ between the opposing ends and the second bottom surface, the distance A ₂ between the opposing proximal portion and the second bottom surface, the distance B ₁ between the pair of side edges, B ₃ and the distance B ₂ between the pair of adjacent side surfaces, and using equations (1) and (2) described in Embodiment 1 above, the first bulge ratio R ₁ and the second bulge are determined. The rate _R2 was calculated. Furthermore, the same cross-sectional observation and leak test as in the above example was performed. The results are shown in Table 1.

In Examples 1-1 to 1-4, the first bulge ratio R ₁ and the second bulge ratio R ₂ were higher than in Comparative Example 1, and no defects were observed in cross-sectional observation and leak tests. . As shown in Reference Example 1, as a result of four measurements at each distance, the average value of the first bulge ratio _R1 was 0.5%, and the average value of the second bulge ratio _R2 was 0.5%. %Met. In a heat exchanger plate having such a swelling ratio, it is considered that the base material and the fitting member are suitably forge-welded. Regarding the measurement results of four times for each distance, the first bulge ratio R ₁ has more variation than the second bulge ratio R ₂ (among the examples, the minimum value of the first bulge ratio R ₁ is 0 .3% and the maximum value is 0.8%, whereas the minimum value of the second bulge ratio _R2 is 0.5% and the maximum value is 0.7%). In Comparative Example 1, as a result of cross-sectional observation, it was found that the opposing surface and the pair of second side surfaces were hardly bulged visually, and a gap was observed between the fitting member and the first bottom surface.

<Other embodiments>
The present disclosure is not limited to the embodiments described above and illustrated in the drawings; for example, the following embodiments are also included within the technical scope of the present disclosure, and various modifications other than those described below may be made without departing from the spirit of the disclosure. It can be implemented by

(1) In addition to the embodiments described above, the shapes of the groove and the fitting member can be changed as appropriate. The pattern of the grooves formed on the surface of the base material (the planar shape of the flow path through which the heat transfer medium passes) is not particularly limited. Furthermore, the dimensions and cross-sectional shape of the groove are not particularly limited. Furthermore, the thickness of the fitting member is not particularly limited, and may be any thickness that ensures pressure resistance and airtightness in consideration of the pressure of the heat transfer medium passing through the internal space.

(2) In the above embodiment, both of the pair of second side surfaces have a bulged shape, but the present invention is not limited to this. For example, only one of the pair of second side surfaces may be bulged.

(3) The distance _A2 may be configured such that the first expansion rate _R1 is 0.3% or more for both the distance _A1 and the distance _A3 . Also, the distance _B2 may be configured such that the second expansion rate _R2 is 0.5% or more for both the distance _B1 and the distance _B3 .

DESCRIPTION OF SYMBOLS 1,201...Base material, 1A,201A...Surface, 3,203...Fitting member, 10,210...1st groove part, 11,211...1st side surface, 20,220...2nd groove part, 21,221...th 2 side surfaces, 21B1, 21B3... side surface end, 21B2... side surface proximate portion, 22, 222... second bottom surface, 31, 231... opposing surface, 31A1, 31A3... opposing end, 31A2... opposing proximate portion, 100... heat transfer board

Claims (3)

a base material made of metal, the base material having a first groove portion and a second groove portion recessed from the first groove portion;
a fitting member made of metal and fitted into the first groove portion,
The first groove portion has a pair of first side surfaces that extend downward from the surface of the base material and face each other,
The second groove portion is
A bottom surface that constitutes a bottom of the second groove portion;
a pair of second side surfaces rising from the bottom surface and facing each other;
a distance between the pair of second side surfaces is smaller than a distance between the pair of first side surfaces;
one of the pair of second side surfaces bulges toward the other of the second side surfaces , and the other of the second side surfaces bulges toward the one of the second side surfaces ,
The fitting member has an opposing surface that faces the bottom surface and bulges out toward the bottom surface ,
A heat transfer plate , wherein a contact portion between the first groove portion of the base material and the fitting member is metallurgically bonded . The opposing surface is
an opposing end that is an end on the second side surface side;
an opposing proximal portion closest to the bottom surface;
When the distance between the opposing end and the bottom surface is _A1 , and the distance between the opposing proximal portion and the bottom surface is _A2 , a first bulge ratio R that satisfies the following formula (1) The heat exchanger plate according to claim 1, wherein ₁ (%) is 0.3% or more.
R ₁ (%) = {(A ₁ - A ₂ )/2A ₂ }×100...Formula (1) The pair of second side surfaces are
A pair of side end portions which are end portions on the bottom surface side or the opposing surface side;
a pair of side adjacent portions closest to each other;
The heat transfer plate according to claim ₁ or claim ₂ , wherein, when the distance between the pair of side end portions is B1 and the distance between the pair of side adjacent portions is B2, a second expansion rate _R2 (%) satisfying the following formula (2) is 0.5% or more.
R ₂ (%)={(B ₁ −B ₂ )/2B ₂ }×100 (2)

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