JP6162632B2 - Cooler - Google Patents

Description

  The present invention relates to a cooler. In particular, the present invention relates to a collision jet type cooler in which a cooling target such as a semiconductor chip is attached to one side plate of a cooler casing, and a refrigerant collides with the back surface (the inner surface of the casing) of the side plate.

  For cooling semiconductor chips and electronic components, a type of cooler is known in which a cooling target such as a semiconductor chip is attached to one side plate of a housing, and a coolant is jetted toward the back surface of the side plate (the surface facing the inside of the housing). It has been. Such a type of cooler is called a collision jet type because it causes the ejected refrigerant to collide with the back surface of the side plate to which the object to be cooled is attached. In this specification, for convenience of explanation, a side plate that is a side plate of a cooler and to which a cooling target such as a semiconductor chip is attached is referred to as a “base plate”. The surface on which the object to be cooled is attached may be referred to as the “front surface” of the base plate, and the opposite surface (the surface facing the inside of the housing) may be referred to as the “back surface”.

  Examples of impingement jet type coolers are described in Patent Documents 1-3. The coolers of all documents have the following common structure. The cooler includes a casing through which a refrigerant passes, an above-described base plate, fins erected on the back surface of the base plate, a partition plate, and a nozzle. The partition plate is provided in parallel with the base plate, and divides the space in the housing into a first flow channel far from the base plate and a second flow channel close to the base plate. The nozzle extends from the partition plate toward the base plate, and ejects the refrigerant toward the back surface of the base plate. The coolers disclosed in Patent Literature 1 and Patent Literature 2 are further provided at one end of the housing, and a supply port for supplying a refrigerant to the first flow path and a housing end on the opposite side of the supply port Provided with a discharge port for discharging the refrigerant from the second flow path. Patent Document 3 does not clearly show the supply port and the discharge port, and the location is unknown, but there are always locations corresponding to the supply port and the discharge port.

  The coolers disclosed in Patent Documents 1 and 2 include a plurality of parallel fins. The refrigerant ejected from the nozzle collides with the back surface of the base plate, flows along the fins, and then flows toward the discharge port. In the cooler of Patent Document 1, the plurality of fins are provided at right angles to the flow direction of the refrigerant toward the discharge port. On the other hand, in the cooler of patent document 2, the several fin is provided in parallel with the flow direction of the refrigerant | coolant which goes to a discharge port. In the cooler disclosed in Patent Document 3, only one fin is provided immediately below the nozzle. The fin is tapered and extends from the upper end toward the root. The refrigerant flows so as to spread along the taper of the fin.

JP 2011-166113 A JP 2007-281163 A JP 2005-344974 A

  In the cooler of Patent Document 1 in which a plurality of parallel fins are perpendicular to the direction of the refrigerant flow, the resistance to the refrigerant flow is large, and the pressure loss of the refrigerant flow is large. In the cooler of Patent Document 2 in which a plurality of parallel fins are parallel to the direction of the refrigerant flow, the pressure loss of the refrigerant flow is small, but since the refrigerant flows in parallel with the fins, heat exchange between the fins and the refrigerant The efficiency is not high.

  The present specification relates to a cooler of the same type as the coolers disclosed in Patent Documents 1 and 2, devising the shape of the fin, reducing the pressure loss of the refrigerant flow, and improving the heat exchange efficiency between the fin and the refrigerant. Provide technology to achieve both.

  As described above, the cooler disclosed in this specification includes a housing, a base plate, a plurality of fins, a partition plate, and a nozzle. The base plate is one side plate of the housing, and an object to be cooled is attached to the front surface. The plurality of fins are erected on the back surface of the base plate. The plurality of fins are arranged in parallel to each other. The partition plate is provided in parallel with the base plate, and divides the space in the housing into a first flow channel far from the base plate and a second flow channel close to the base plate. The nozzle extends from the partition plate toward the base plate, and ejects the refrigerant from the first flow path toward the back surface of the base plate. The casing of the cooler is provided with a refrigerant supply port and a discharge port. The supply port communicates with the first flow path, and the discharge port communicates with the second flow path. The supply port and the discharge port are provided at the opposite ends of the cooler casing and determine the flow direction of the refrigerant. In other words, the supply port and the discharge port are provided at both ends of the housing in a direction parallel to the partition plate, and the refrigerant flows from the supply port toward the discharge port. In the cooler disclosed in this specification, the fin has the following configuration in addition to the above-described structure. That is, the fin is bent when viewed from the direction orthogonal to the base plate, and the bent portion is positioned so as to overlap with the nozzle, and extends from the bent portion to both sides toward the downstream side of the refrigerant flow. It is growing.

  A space is provided between the upper end of the fin and the partition plate, and the space serves as a refrigerant flow path toward the discharge port. The refrigerant flow is turbulent between the fins, but “downstream of the refrigerant flow” means downstream in the refrigerant flow between the upper end of the fin and the partition plate. In other words, the direction of the refrigerant flow coincides with the direction from the refrigerant supply port to the discharge port when viewed from the direction orthogonal to the base plate. In addition, the bent portion may not overlap the nozzle in all of the plurality of fins. In some fins, the bent portion only needs to overlap the nozzle. In addition, a plurality of nozzles are provided in a direction orthogonal to the refrigerant flow, and one fin has the above-described bent portion with respect to each nozzle, and a fin that extends from each bent portion toward the refrigerant downstream. As a result, the fins may be corrugated.

  The flow of the refrigerant in the cooler having the above structure will be described. The refrigerant ejected from the nozzle collides with the back surface of the base plate through the bent portions of the parallel fins. The refrigerant bounced off from the back surface flows along the surface of the fin spreading from the bent portion toward the downstream of the refrigerant flow, and eventually flows out to the space between the upper end of the fin and the partition plate and flows toward the discharge port. Since the fins are not perpendicular to the refrigerant flow as in the cooler of Patent Document 1, the pressure loss of the refrigerant flow is smaller than that of the cooler of Patent Document 1. Further, since the refrigerant collides with the bent fin and flows downstream while the flow is expanded, the interference between the fin and the refrigerant is stronger than the cooler of Patent Document 2 in which the refrigerant flow and the fin are parallel, and the heat between them. The exchange efficiency is higher than that of the cooler of Patent Document 2.

  The present specification relates to an impinging jet type cooler in which a plurality of fins are provided on the back surface of a base plate to which an object to be cooled is attached, and the refrigerant is jetted toward the back surface, and the pressure of the refrigerant flow in the vicinity of the fins Provided is a technique for reducing both loss and improving heat exchange efficiency between the fin and the refrigerant. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a perspective view of the cooler of an example (a part of case is cut). It is a top view of the cooler of an example (cutting the top plate of a case). It is sectional drawing along the IIB-IIB line | wire of FIG. 2A. It is sectional drawing along the IIC-IIC line | wire of FIG. 2A. A graph showing an example of the relationship between the bending resistance coefficient C _D tilt angle Th and the channel of the fin. It is a perspective view of the cooler of a modification (a part of case is cut). It is a top view of the cooler of a modification (cutting the top plate of a case). It is a perspective view of a reference cooler (a part of a case is cut). It is side surface sectional drawing of a reference cooler.

  The cooler according to the embodiment will be described with reference to the drawings. FIG. 1 is a perspective view of the cooler 2. However, in FIG. 1, a part of the parts is cut and drawn so that the internal structure of the cooler 2 can be understood. Hatching represents the cut surface. FIG. 2A shows a plan view of the housing 7 excluding the top plate 7a. FIG. 2B shows a cross section (side cross-sectional view) along the line IIB-IIB in FIG. 2A. FIG. 2B corresponds to a longitudinal section that traverses a long hole nozzle (described later) in the longitudinal direction. FIG. 2C shows a cross section (transverse cross section) along the line IIC-IIC in FIG. 2A.

  The cooler 2 is a device that cools the objects to be cooled 92a, 92b, and 92c such as a semiconductor chip. The objects to be cooled 92a to 92c are attached to the front surface 3a of the base plate 3 via an insulating plate 91 that also serves as a heat spreader. The base plate 3 constitutes one side plate of the housing 7. Here, it should be noted that the “front surface” is a convenient expression for distinguishing two planes of the base plate 3. In the present specification, in the base plate 3, the surface facing the outside of the cooler 2 is referred to as “front surface 3 a”, and the surface facing the inside of the cooler 2 is referred to as “back surface 3 b”. The cooler 2 passes the refrigerant through the inside of the housing, in particular, the back side of the base plate 3 to cool the object to be cooled. The refrigerant is typically water or LLC (Long Life Coolant).

  A plurality of fins 4 are attached to the back surface 3 b of the base plate 3. The plurality of fins 4 are arranged in parallel with their planes facing each other. Each fin 4 has a corrugated plate shape whose bending direction changes alternately. The shape of the fin 4 will be described later.

  The casing 7 of the cooler 2 is a rectangular parallelepiped, and the internal space is a refrigerant flow path. Inside the housing 7, a partition plate 5 that divides the internal space into a space facing the back surface 3 b of the base plate 3 and a space far from the base plate 3 is provided. The former space is referred to as a first flow path 12, and the latter space is referred to as a second flow path 14.

  One end of the housing 7 is provided with a refrigerant supply port 8 that communicates with the first flow path 12 (space farther from the base plate 3 than the partition plate 5), and the second flow path 14 (base plate more than the partition plate 5). 3) (Refer to FIG. 2B). Hereinafter, the refrigerant supply port 8 is simply referred to as a supply port 8, and the refrigerant discharge port 9 is simply referred to as a discharge port 9.

  The supply port 8 and the discharge port 9 are provided in each of two opposing side plates among the side plates of the housing 7 that intersect with the base plate 3. In FIG. 2B, the supply port 8 is provided on the left side plate in the drawing, and the discharge port 9 is provided on the right side plate in the drawing. That is, the refrigerant flows from left to right in the drawing. In other words, the refrigerant flows in the positive direction of the X axis in the coordinate systems shown in FIGS. 1, 2A, and 2B. That is, the X axis corresponds to the direction of the refrigerant flow, and the positive direction of the X axis corresponds to the downstream side of the refrigerant flow.

  Three nozzles 6 extend from the partition plate 5 toward the base plate 3. As well shown in FIG. 2A, the nozzle 6 has a long opening (flow path) along the flow of the refrigerant. The three nozzles extend in parallel along the flow direction. The refrigerant supplied from the supply port 8 passes through the first flow path 12 and then moves to the second flow path 14 through the nozzle 6. At this time, the refrigerant ejected from the nozzle 6 collides with the back surface of the base plate 3. The refrigerant flowing through the second flow path 14 is finally discharged from the discharge port 9.

  As well shown in FIG. 2C, the second flow path 14 also corresponds to a groove having a U-shaped cross section, and the U-shaped opening side faces the fin 4. That is, the second flow path 14 communicates with the space between the fins. Further, the tip 6 a of the nozzle 6 is in contact with the upper end 4 a of the fin 4.

  The fin 4 will be described. As described above, the plurality of fins 4 are parallel to each other, and each fin 4 has a corrugated plate shape that is alternately bent. 1 and 2A, the range indicated by the symbol A indicates the vicinity of the one fin 4 that intersects with the opening tip of the nozzle 6. In range A, fin 4 has bent portions 4b and 4c. When viewed from the direction orthogonal to the base plate 3, the bent portion 4b overlaps the opening of the nozzle 6, and the fin 4 faces both sides of the bent portion 4b toward the downstream of the refrigerant flow (the positive direction of the X axis in the figure). It stretches to expand. 2A corresponds to a view seen from a direction orthogonal to the base plate 3. FIG. Three nozzles 6 are provided in a direction orthogonal to the refrigerant flow, and the fins 4 have bent portions on both sides of the range A as well. From the bent part located so as to intersect with each nozzle 6, the fin 4 extends toward the refrigerant downstream, and the fin is connected at the expanded end. As a result, the fin 4 has a corrugated shape that is alternately bent in the opposite direction.

  The range indicated by the symbol B in FIG. 2A indicates a portion that intersects the opening of the nozzle 6 of the fin 4 at another location. Also here, the fin 4 is bent, and when viewed from the direction orthogonal to the base plate 3, one bent portion 4b overlaps the opening of the nozzle 6, and spreads from the bent portion to both sides toward the downstream side of the refrigerant flow. Yes. When viewed from the direction orthogonal to the base plate 3, the portions where the fins 4 and the nozzles 6 cross each other correspond to the bent portions of the fins, and the fins spread from the respective bent portions to both sides toward the downstream of the refrigerant flow. Yes.

  The flow of the refrigerant will be described with reference to FIGS. 1, 2A, and 2B. The thick line with the arrow of FIG.1, FIG.2A, FIG.2B has shown the flow of the refrigerant | coolant. The symbol “Fin” represents the refrigerant flowing into the cooler 2 (representing the flow in the first flow path 12 in FIG. 1), and the symbol “Fout” represents the refrigerant discharged from the cooler 2. ing. The refrigerant supplied from the supply port 8 flows downstream through the first flow path 12. The refrigerant changes the flow direction toward the base plate 3 through the long opening of the nozzle 6 while flowing through the first flow path 12. The refrigerant is ejected vigorously from the nozzle 6 toward the back surface 3 b of the base plate 3. The refrigerant that has collided with the back surface 3 b of the base plate 3 rebounds, passes through the parallel fins 4, and moves to the second flow path 14.

  In FIG. 2A, the thick line indicating the refrigerant flow is partially broken, indicating that the refrigerant is flowing beyond the partition plate 5 (the back side of the drawing). In FIG. 2B, a part of the thick line indicating the refrigerant flow is a broken line, indicating that the refrigerant is flowing beyond the nozzle 6 (the back side in the drawing).

  As clearly shown in FIG. 2A, the refrigerant ejected from the nozzle 6 passes through the bent portion 4 b of the fin 4 and collides with the back surface of the base plate 3. On both sides of the bent portion 4 b, the fins 4 expand toward the downstream side of the refrigerant flow, so that the refrigerant flows along the expansion of the fins 4. 2C, a wide space (second flow path 14) is secured between the upper end 4a of the fin 4 and the partition plate 5, and the refrigerant flowing along the fin 4 has a plurality of refrigerants. It moves from the space between the fins 4 to the second flow path 14.

  In the second flow path 14, the refrigerant flows toward the discharge port 9. Finally, the refrigerant is discharged from the discharge port 9. A refrigerant pipe (not shown) is connected to the supply port 8 and the discharge port 9, and a tank and a pump (not shown) are connected to the tip of the refrigerant pipe. The refrigerant is sent to the cooler 2 by the tank, the pump, and the refrigerant pipe, and is recovered from the cooler 2.

  As described above, the cooler 2 increases the cooling capacity by vigorously spraying the refrigerant onto the back surface 3b of the base plate 3 to which the object to be cooled is attached. Further, the refrigerant bounced off the base plate 3 takes heat from the fins 4 while passing between the plurality of parallel fins 4, and cools the base plate 3 (that is, the object to be cooled). The cooler having such a structure is called an impinging jet type cooler.

  In particular, the refrigerant ejected from the nozzle 6 and bounced off the back surface 3b of the base plate 3 flows along the fins 4 spreading toward the downstream of the refrigerant flow. Here, since the fins 4 are inclined toward the downstream side of the refrigerant flow, the resistance to the refrigerant flow is smaller than when the fins are orthogonal to the refrigerant flow. That is, the cooler 2 of the embodiment has a smaller refrigerant flow pressure loss than a cooler in which fins are orthogonal to the coolant flow.

  On the other hand, compared with the case where the fins are provided in parallel to the refrigerant flow, in the cooler 2 of the embodiment, the refrigerant has a higher frequency of collision with the fins 4 (in other words, the refrigerant is pressured against the fins 4). Add). Therefore, the cooler 2 of the embodiment has better cooling efficiency than a cooler in which fins extend parallel to the refrigerant flow.

Figure 3 shows an example of the relationship between the bending resistance coefficient C _D relative inclination angle Th and the refrigerant flow in the fin 4. Note that the inclination angle Th of the fin 4 is defined as an angle between the refrigerant flow direction L and the direction R in which the fin 4 extends, as shown in FIG. 2A. In other words, the inclination angle Th is the angle of the fin 4 extending from the bent portion 4b with respect to the refrigerant flow. As shown in FIG. 3, the drag coefficient _{C D} is simply increased from 0.0 to 1.0 between the inclination angle Th is 0 (degrees) from 90 degrees. By suitably determined inclination angle Th of the fins 4 in the range of 0 (degree) and 90 (degrees), it is possible to achieve an appropriate resistance coefficient C _D.

  A modified cooler 102 will be described with reference to FIGS. 4 and 5. The modified cooler 102 is different from the previous cooler 2 in that the fins 104 are provided with slits 105. The characteristic structure including the slit 105 of the cooler 102 is as follows. The cooler 102 includes a plurality of nozzles 6 in a direction orthogonal to the direction of the refrigerant flow. The fins 104 are bent when viewed from a direction orthogonal to the base plate 3, and the bent portions are positioned so as to overlap the nozzles 6. Further, the fin 104 extends from the bent portion to both sides so as to expand toward the downstream side of the refrigerant flow. Further, the fin 104 has a slit 105 at a position corresponding to an intermediate point between the adjacent nozzles 6 when viewed from a direction orthogonal to the base plate 3.

  The refrigerant flow in the cooler 102 will be described. The refrigerant ejected from the nozzle 6 and bounced off from the back surface of the base plate 3 flows along the fins 104 spreading toward the downstream side of the refrigerant flow. Since the slit 105 is provided at the tip of the fin 104 extending and extending toward the downstream, a part of the refrigerant flows downstream through the slit 105. The remaining part of the refrigerant flows downstream through the second flow path 14 between the upper end of the fin and the partition plate 5, as in the cooler 2 described above. Since a part of the refrigerant flows smoothly downstream through the slit 105, the cooler 102 has a further reduced pressure loss of the refrigerant flow as compared with the previous cooler 2.

  The slit 105 may be located immediately below the nozzle 6. In this case as well, a similar pressure loss reduction can be obtained, and the refrigerant ejected from the nozzle 6 maintains a high flow velocity and collides with the back surface of the base plate 3, and then the tip effect (temperature boundary layer) at the side surface end of the fin 4. Therefore, high heat exchange efficiency can be obtained.

  (Reference) A reference cooler 202 will be described with reference to FIGS. In the cooler 202, the plurality of fins 204 extend in a direction orthogonal to the direction of the refrigerant flow when viewed from the direction orthogonal to the base plate 3. Further, the plurality of parallel fins 204 are inclined so that the upper end 204 a is close to the supply port 8 and the root 204 b is close to the discharge port 9. In other words, the plurality of fins 204 extend from the back surface of the base plate 3 so as to incline toward the upstream side of the refrigerant flow.

  The thick line in FIG. 7 represents the refrigerant flow in the cooler 202. The refrigerant Fin that has entered from the supply port 8 flows toward the back surface of the base plate 3 through the nozzle 6 while flowing through the first flow path 14. Here, since the fins 204 are inclined, the refrigerant flow strikes the back surface of the base plate 3 obliquely. Thereafter, the refrigerant flows between the plurality of fins 204 toward the supply port 8 so as to return temporarily, and then flows toward the discharge port 9. In addition, the broken line part of the thick line of FIG. 7 represents that a refrigerant | coolant flows through the other side (paper surface back side) of the nozzle 6. FIG.

FIG. 7 shows the definition of the inclination angle Th of the fin 204. This inclination angle Th also drag coefficient C _D of the graph shown in FIG. 3 is established.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2, 102, 202: cooler 3: base plate 4, 104, 204: fin 4a: upper end 4b, 4C: bent portion 5: partition plate 6: nozzle 6a: nozzle tip 7: casing 7a: top plate 8: refrigerant supply Mouth (supply port)
9: Refrigerant discharge port (discharge port)
12: 1st flow path 14: 2nd flow path 91: Insulating plate 92a: Cooling object 105: Slit

Claims (1)

An impinging jet type cooler,
A casing through which the refrigerant passes;
One side plate of the housing, a base plate to which a cooling object is attached to the front surface;
A plurality of parallel fins standing on the back surface of the base plate;
A partition plate that is provided in parallel to the base plate, and divides the space in the housing into a first channel far from the base plate and a second channel near the base plate;
A supply port that is provided at one end of the housing and supplies a refrigerant to the first flow path;
A nozzle extending from the partition plate toward the base plate, and ejecting a refrigerant toward the back surface of the base plate;
An exhaust port that is provided at the end of the casing opposite to the supply port, and that discharges the refrigerant from the second flow path;
With
When viewed from the direction orthogonal to the base plate, the fin is bent, the bent portion is positioned so as to overlap the nozzle, and extends from the bent portion to both sides toward the downstream side of the refrigerant flow. A cooler characterized by extending.

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