JP2001250892A - Heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink of high connection strength between a fin and a base plate. SOLUTION: A heat sink 1 comprises a base plate 2 provided at a heat- exchange point for heat accumulation or heat absorption, and many fins 5 erected on the base plate 2. A dam 4 is provided to hold a joint material 9 which solidifies to provide a bonding function in a specified range on the surface of the base plate 2. One end of a fin 3 is inserted in the joint material 9 for integral connection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink for increasing a heat exchange area in various heat exchangers or heat transfer devices.

[0002]

2. Description of the Related Art In heat-related equipment such as heat pipes,
Conventionally, a heat sink is provided to increase the heat exchange area by increasing the heat radiation area or heat absorption area. One example of the heat sink is disclosed in Japanese Patent Application Laid-Open No. 8-130.
274.

[0003] The structure described in this publication includes a flat substrate and fins having one end attached to the upper surface of the substrate. And a structure in which one of the folded end plates of the corrugated plate is brazed to the substrate to join them together. According to this heat sink, since the tips of two fins adjacent to each other are connected to each other,
There is an advantage that the fins have a substantial strength in the thickness direction and that the fins are prevented from being bent in that direction.

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Laid-Open No.
In the structure described in JP-A-130274, since a bonding material such as brazing or solder is sandwiched between flat surfaces, the bonding material in a heated and molten state is forced to flow out of the substrate. Accordingly, a necessary amount of the bonding material is not held between the substrate and the bent end plate portion, and there is a possibility that the connection strength between the fin and the substrate is eventually insufficient.

The present invention has been made in view of the above circumstances, and has as its object to provide a heat sink having a high connection strength between a fin and a base plate.

[0006]

Means for Solving the Problems and Action Therefor To achieve the above object, an invention according to claim 1 is provided with a base plate provided at a heat exchange target portion which generates heat or absorbs heat, and is provided upright on the base plate. A heat sink provided with a plurality of fins, wherein a weir portion is provided for holding a bonding material that solidifies to form an adhesive function within a predetermined range on the surface of the base plate, and one end of the fin is provided on the bonding material. Are integrally connected with each other while being inserted.

Therefore, according to the first aspect of the present invention, when the fins are joined to the base plate, for example, a joining material such as solder which has been heated and melted flows out onto the surface of the base plate. Is prevented. Accordingly, a necessary amount of joining material for joining each fin to the base plate is held between the base end of each fin and the base plate, so that the connection strength between each fin and the base plate is high.

[0008] The invention described in claim 2 is the first invention.
In the configuration, each of the fins has a spread in the surface direction of the base plate, and is formed integrally with the base surface in a state protruding from one surface of the base surface serving as a mounting portion for the base plate. And a base structure in which one adjacent fin and the base surface are connected together, and the other adjacent fin and the tip of the protrusion are connected together. It is a feature.

Therefore, according to the second aspect of the present invention, since a plurality of base surfaces extending in the surface direction of the bonding material held in the inner region of the weir are provided, a bonding area between the bonding material and the fins is provided. And the connection strength between the fin and the base plate is further improved accordingly. According to the second aspect of the present invention, since the tips of two or two fins adjacent to each other are connected to each other, the substantial strength of each fin in the thickness direction is improved. And bending in that direction is prevented beforehand.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment according to the present invention will be described with reference to FIGS. Reference numeral 1 indicates a heat sink, and the heat sink 1 includes a base plate 2 and a fin unit 3 attached to an upper surface of the base plate 2. More specifically, the base plate 2 is a portion to be installed or fixed to a portion to be subjected to heat exchange. As an example, a rectangular or rectangular flat plate made of Cu or Al is used.

An upper surface of the base plate 2 in FIG. 1 has a mounting recess 4 having a rectangular or square shape as a whole.
(Corresponding to a weir portion of the present invention). The mounting recess 4 is a portion to which the fin unit 3 is mounted, and the size in the plan view is slightly larger than the size in the plan view of the fin unit 3 mounted in the desired posture. Have been. That is, the fin unit 3
Are formed as depressions. Further, the bottom surface of the mounting recess 4 is a flat surface parallel to the lower surface of the base plate 2. Further, the depth of the mounting recess 4 is set to a value several times the thickness of the base surface 6 described later.

On the other hand, the fin unit 3 is formed by integrally forming a plurality of fins 5 in a parallel state. The fin unit 3 is thinner than the base plate 2 and has a structure in which a flat plate made of Cu or Al is bent in a zigzag shape as a whole. That is, the fin unit 3 includes a plurality of base surfaces 6 serving as attachment portions to the base plate 2, a plurality of top surfaces 7 facing the base plate 2 in parallel, and the top surface 7.
And a plurality of side surfaces 8 which are continuous with the edge portion of the base plate 6 and which are perpendicular to the base plate 2. Note that the side surface portion 8 corresponds to the protrusion of the present invention.

The top surface portion 7, the base surface portion 6, and the side surface portion 8 are
Each has a flat surface. In other words, the pair of side surfaces 8 and the top surface 7 sandwiched therebetween form one tunnel-shaped space. One fin 5 is formed by one base surface portion 6 and one side surface portion 8 formed integrally with each other.

The fin unit 3 is fixed to the base plate 2 by soldering each base surface 6 to the bottom surface of the mounting recess 4. More specifically, the bottom surface of each base surface portion 6, the base end portion of each side surface portion 8, and the base surface portion 6 are formed by the solidified solder 9 provided inside the mounting recess 4.
The edge of the side surface 8 is joined to the base plate 2. That is, the solder 9 corresponds to the joining material of the present invention. As another example of the joining material, an adhesive made of a synthetic resin is used.

The upper surface of the outermost base surface 6 of the fin unit 3 is covered with the solder 9. The upper surface of the solder 9 is located below the upper surface of the base plate 2. In addition, as the solder 9, a solder having good bondability with the metal used for the base plate 2 and the fin unit 3 and having excellent thermal conductivity is used.

Therefore, according to the heat sink 1 having the configuration shown in FIG. 1, at the time of soldering, the solder 9 is heated to be in a molten state inside the mounting recess 4. That is, the mounting recess 4 functions as a pool for storing the melted solder 9, so that the solder 9 does not flow out onto the surface of the base plate 2 and solidifies inside the mounting recess 4 as it is.

That is, since there is no leakage of the solder 9 from between the fin unit 3 and the base plate 2, a necessary and sufficient amount of the solder 9 is secured, and accordingly, each base surface 6 and each side surface 8 and the base plate 2 Are joined together, so that the fin unit 3 is securely connected to the base plate 2. In other words, the heat sink 1 having a high connection strength between the fin unit 3 and the base plate 2 can be obtained.

Next, another embodiment of the present invention will be described with reference to FIG. The example shown here has a configuration in which an enclosure made of a ridge is provided in place of the mounting recess 4. The same members as those in the above specific example are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 4, the heat sink 1 includes a flat base plate 2 made of Cu, and a fin unit 3 made of Al and soldered to its upper surface. The structure of the fin unit 3 is the same as that of the specific example shown in FIG.

On the upper surface of the base plate 2, there is formed a weir portion 10 having a rectangular shape or a rectangular shape as a whole and formed of a ridge. The inner area of the weir portion 10 is a portion to which the fin unit 3 is attached, and the size in the plan view is slightly smaller than the size in the plan view of the fin unit 3 attached in the intended posture. It is formed large. The height of the weir portion 10 with respect to the base plate 2 is set to a value several times the thickness of the base surface portion 6 of the target fin unit 3 as an example. Further weir 10
Is not limited to the triangular shape shown in FIG. 4, but may be, for example, a rectangular shape or a semicircular shape. In addition, the dam part 10 is formed by press work, for example.

On the other hand, weir 10 in base plate 2
The fin unit 3 and the base plate 2 are integrally joined by soldering the respective base surfaces 6 to the inner region of the fin unit 3. That is, the bottom surface of each base surface portion 6, the base end portion of each side surface portion 8, and the edge portions of the base surface portion 6 and the side surface portion 8 are joined to the base plate 2 by the solidified solder 9 provided inside the weir portion 10. I have. The upper surfaces of the outermost base surfaces 6 of the fin unit 3 are covered with the solder 9. Further, the upper surface of the solder 9 is located below the vertex of the weir portion 10. Other configurations are the same as those of the heat sink 1 shown in FIG.

Therefore, according to the heat sink 1 having the structure shown in FIG. 4, the solder 9 is heated during the soldering, so that the solder 9 is in a molten state in the area inside the weir portion 10. That is, weir part 1
The inside space of 0 functions as a pool for storing the melted solder 9, so that the solder 9 does not flow out onto the surface of the base plate 2, but solidifies in the area inside the weir 10. That is, since the solder 9 does not leak from between the fin unit 3 and the base plate 2, a necessary and sufficient amount of the solder 9 is secured, and accordingly,
And each side part 8 and the base plate 2 are respectively joined, and as a result, the fin unit 3
Is securely connected to Therefore, the connection strength between the fin unit 3 and the base plate 2 is high.

Next, another embodiment of the present invention will be described with reference to FIG. The example shown here is an example in which the base plate 2 forms a heat pipe structure. The same members as those in the above specific example are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 5, the heat sink 1 has a flat base plate 2 and a number of fin units 3 soldered to the upper surface thereof. The fin unit 3 has the same structure as that of the specific example shown in FIG.

On the other hand, the base plate 2 has a hollow flat-plate-like container 11 having a rectangular or square shape as a whole, and an injection nozzle 12 attached to one side of the container 11 in a state of being inserted. I have. The mounting recess 4 having the same structure as that of the specific example shown in FIG. That is, the mounting recess 4 has a rectangular shape or a square shape slightly larger than the size of the fin unit 3 in the plan view as a whole. The depth of the mounting recess 4 is determined by the base surface 6 of the fin unit 3.
Is several times the thickness of Solidified solder 9 is provided inside the mounting recess 4.

A working fluid (not shown) is sealed in the container 11 in a state where non-condensable gas is degassed.
That is, the base plate 2 itself is a heat pipe. Although not particularly shown, a wick for circulating the working fluid, a support for preventing deformation, and the like can be provided inside the container 11 as necessary. On the lower surface of the container 11, an electronic element 20 corresponding to a heat exchange target is disposed in close contact. On the other hand, the injection nozzle 12 is a small-diameter pipe for injecting a working fluid or the like, and an end protruding from the container 11 is crushed and sealed. The injection nozzle 12 and the container 11 are both made of Cu or Al.

The operation of the heat sink 1 configured as described above will be described. When the electronic element 20 generates heat, the heat is transmitted to the lower surface of the base plate 2 and to the working fluid sealed therein, and the heat pipe operation is automatically started. That is, the working fluid that has been heated and evaporated flows upward, and radiates heat to the solder 9 and the fin unit 3 to condense.

As described above, according to the heat sink 1 having the structure shown in FIG. 5, various effects similar to those of the specific example shown in FIG. 1 can be obtained, and in addition, the base plate 2 functions as a flat heat pipe. As a result, heat is quickly and uniformly diffused in the plane direction, so that the heat of the electronic element 20 is efficiently supplied to the fin unit 3 and, as a result,
The heat radiation performance of the heat sink 1 as a whole can be further improved.

Next, another embodiment of the present invention will be described with reference to FIGS. The example shown here is a configuration in which the solder 9 is prevented from flowing out by a member different from the base plate 2. The same members as those in the above specific example are denoted by the same reference numerals, and detailed description thereof will be omitted. The heat sink 1 includes a flat base plate 2 and a fin unit 3 soldered to an upper surface thereof. Note that the mounting recess 4 and the weir 10 are not formed on the upper surface of the base plate 2 and are flat surfaces.

On the other hand, the structure of the fin unit 3 is substantially the same as that of the specific example shown in FIG. A large number of circular or elliptical holes 13 are formed in each base surface 6 of the fin unit 3. That is, the holes 13 are arranged at predetermined intervals in the length direction of the base surface 6.

A mounting cover 14 is provided on the upper surface side of the base surface 6 of the fin unit 3. The mounting cover 14 is for surrounding the periphery of the base surface 6 of the fin unit 3 to prevent the solder 9 from flowing out, and a part of the mounting cover 14 is placed on the fin unit 3 so as to cover a part of the upper surface of the base plate 2. It is designed to adhere to. That is, the mounting cover 14 includes a flat plate portion 15 formed of a rectangular or square plate-like body, and a weir portion 16 protruding along the edge of one side of the flat plate portion 15.

The size in the plan view of the flat plate portion 15 is set slightly larger than the size in the plan view of the fin unit 3 mounted in the desired posture. Also, flat plate 1
5 has an opening 17 for conducting the pair of side surfaces 8 of the fin unit 3. That is, the shape and size of each opening 17 in the plan view substantially match the shape and size of each top surface 7.

On the other hand, the weir 16 has a rectangular or rectangular cross section. The joint portion of the weir portion 16 with the base plate 2 forms a flat surface and is in close contact with the upper surface of the base plate 2. The height of the weir portion 16 from the flat plate portion 15 is set to a value obtained by adding the thickness of the base surface portion 6 and the thickness of the solder 9 in the fin unit 3.

The mounting cover 14 having the above structure passes the two side surfaces 8 sandwiching the top surface 7 through the opening 17 and
6 is connected to the base plate 2 and the fin unit 3 in a posture in which the base plate 6 is in close contact with the upper surface of the base plate 2. That is, the solder 9 for joining the base surface 6 of the fin unit 3 and the base plate 2 is contained in a solidified state inside the weir 16, and enters the gap between the edge of the base 6 and the weir 16. The dam 16 is joined to the base plate 2 by the solder 9. The solder 9 is also provided inside each of the holes 13 and on the upper peripheral portion of each of the holes 13, and the flat plate portion 15 of the mounting cover 14 is formed by the solder 9 in this portion.
Is joined to the base surface portion 6. That is, the fin unit 3, the base plate 2, and the mounting cover 14 are integrally connected by the solder 9.

Therefore, according to the heat sink 1 having the structure shown in FIG. 6, the solder 9 is heated and melted inside the mounting cover 14 at the time of soldering. That is, the mounting cover 14 functions as a pool for storing the melted solder 9, so that the solder 9 does not flow out onto the surface of the base plate 2 and solidifies inside the mounting cover 14 as it is. That is, since the solder 9 does not leak from between the fin unit 3 and the base plate 2,
A necessary and sufficient amount of solder 9 is secured, and accordingly, each base surface portion 6 and each side surface portion 8 and the base plate 2 are joined. As a result, the fin unit 3 is securely connected to the base plate 2, and the heat sink 1 has a high connection strength between them.

In particular, in the heat sink 1 having the structure shown in FIG. 6, a part of the solder 9 is engaged with the peripheral portion of each hole 13 on the upper surface of each base surface portion 6, so that a so-called anchor effect is obtained. Unit 3 and base plate 2
The connection strength with the connection is further increased. Further, in the heat sink 1 having the configuration shown in FIG. 6, since the solder 9 is prevented from leaking by the mounting cover 14 which is a so-called separate member, a general-purpose flat plate material can be used as the material of the base plate 2.
In other words, processing on the surface of the base plate 2 such as a press becomes unnecessary.

Next, still another embodiment of the present invention will be described with reference to FIG.
It will be described based on. The example shown here is an example in which the fin unit 3 is plated with copper. The same members as those in the above specific example are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 8, the heat sink 1 includes a plate-shaped base plate 2 made of Cu, and a fin unit 3 made of Al and soldered to its upper surface.

On the upper surface of the base plate 2, a mounting recess 4 having the same structure as that of the embodiment shown in FIG. 3 is formed. That is, the mounting recess 4 has a rectangular shape or a square shape slightly larger than the size of the fin unit 3 in the plan view as a whole. The depth of the mounting recess 4 is several times the thickness of the base 6 in the fin unit 3. Lead (Pb) -tin (Sn) is provided inside the mounting recess 4.
The system solder 9 is provided in a solidified state.

On the other hand, as the shape of the fin unit 3, the same structure as that of the specific example shown in FIG. The thickness of the fin unit 3 is, for example, 0.3 mm to 0.6 mm.
It has become about. Further, a predetermined range of a portion of the fin unit 3 on the base plate 2 side is plated with Cu, and the portion serves as a plating portion 18.

More specifically, the plating portion 18 is formed on each base surface portion 6.
It is provided so as to integrally cover the upper and lower surfaces and the edge surface, the left and right surfaces and the edge surface of each side surface portion 8, and has a thickness of about 1 μm to 10 μm as an example. In addition, as a plating method for the fin unit 3, a conventionally known means such as a copper cyanide plating method, a copper sulfate plating method, or a copper pyrophosphate plating method can be employed. Further, the plating process on the fin unit 3 is performed prior to the joining process (soldering) between the fin unit 3 and the base plate 2.

The height h of the plated portion 18 is set to, for example, about 5 mm, which is larger than the thickness of the base portion 6 and the thickness of the solder 9 in the fin unit 3. In other words, when soldering,
The solder 9 does not contact the base portion of the fin unit 3, particularly, the base edge of each side surface 8.

Therefore, according to the heat sink 1 having the structure shown in FIG. 8, since the fin unit 3 made of Al is provided with the plated portion 18 made of Cu plating, the joint surface of the fin unit 3 with the solder 9 is formed of Cu. Therefore, it is possible to use a solder 9 of a type that is not suitable for joining Al, and since the solder 9 is a general-purpose solder having a low unit price, the cost of the heat sink 1 can be suppressed.

According to the heat sink 1 having the structure shown in FIG. 8, although the inclusion is provided between the solder 9 and the fin unit 3, the inclusion has a higher thermal conductivity than that of Al. Therefore, the thermal resistance between the base plate 2 and each of the base surfaces 6 is suppressed, and as a result, the heat sink 1 having excellent heat dissipation ability can be obtained.

Next, another embodiment of the present invention will be described with reference to FIG. The example shown here is an example in which the fin unit 3 is plated with solder. The same members as those in the above specific example are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 9, the heat sink 1 includes a plate-like base plate 2 made of Cu, and a fin unit 3 made of Al and soldered to the upper surface thereof.

On the upper surface of the base plate 2, a dam 10 having the same structure as that of the embodiment shown in FIG. 4 is formed. That is, the weir portion 10 is a ridge having a triangular cross section, and has a rectangular shape or a square shape slightly larger than the size of the fin unit 3 in the plan view as a whole. The depth of the weir portion 10 is a value several times the thickness of the base surface portion 6 in the fin unit 3. Further, the solder 9 is provided in a solidified state inside the weir portion 10. As the solder 9, a zinc (Zn) -tin (Sn) -indium (In) -based or Zn-Sn-bismuth (Bi) -based solder is employed.

On the other hand, as the shape of the fin unit 3, the same structure as that of the specific example shown in FIG. The thickness of the fin unit 3 is, for example, 0.3 mm to 0.6 mm.
It has become about. Further, a predetermined range of a portion on the base plate 2 side of the fin unit 3 is plated with a solder having the same composition as the solder 9 provided on the weir portion 10, and the portion serves as a plating portion 18. .

Specifically, the plating portion 18 is formed on each base surface portion 6.
It is provided so as to integrally cover the upper and lower surfaces and the edge surface, the left and right surfaces and the edge surface of each side surface portion 8, and has a thickness of about 1 μm to 10 μm as an example. In addition, as a plating method for the fin unit 3, a conventionally known means such as a copper cyanide plating method, a copper sulfate plating method, or a copper pyrophosphate plating method can be employed. Further, the plating process on the fin unit 3 is performed prior to the joining process (soldering) between the fin unit 3 and the base plate 2.

The height h of the plated portion 18 is set to, for example, about 5 mm, which is larger than the thickness of the base portion 6 of the fin unit 3 and the thickness of the solder 9 provided inside the weir portion 10. Is also a large value. That is, when performing soldering, the solder 9 does not come into contact with the base portion of the fin unit 3, particularly, the base edge portion of each side surface portion 8.

Therefore, according to the heat sink 1 having the structure shown in FIG. 9, the provision of the plated portion 18 allows the fin unit 3 to be joined to the solder 9 in a bonding surface.
Since the composition is substantially the same as that of the solder 9 for joining the fin unit 3 and the base plate 2, the fin unit 3
Efficiency of the connecting process between the base plate 2 and the base plate 2 can be improved. This is because the fin unit 3 and the solder 9 are bonded better and more securely than when the Zn-Sn-In-based or Zn-Sn-Bi-based solder 9 is bonded to Al.

In each of the above embodiments, the serpentine fin unit is illustrated. However, the present invention is not limited to the above embodiments. For example, flat fins having individually independent structures may be employed. it can.

[0049]

As is apparent from the above description, according to the first aspect of the present invention, the heat sink provided with a large number of fins erected on the base plate via the joining material is solidified and has an adhesive function. Is provided, and a weir portion is provided for holding the joining material in a predetermined range on the surface of the base plate, and the joining material is integrally connected with one end of the fin inserted therein, and the joining material is placed on the base plate. Since it can be prevented from flowing out and a required amount of the joining material can be held at a desired position, the connection strength between each fin and the base plate can be improved.

According to a second aspect of the present invention, each fin has a width extending in the plane direction of the base plate, and the base surface is a mounting portion for the base plate, and the base surface protrudes from one surface of the base surface. And a protruding portion formed integrally with the protruding portion, further integrally connecting one adjacent fin and the base surface portion, and integrally connecting the other adjacent fin and the tip of the protruding portion. Therefore, by providing a plurality of base surfaces extending in the surface direction of the bonding material held in the inner region of the weir, the bonding area between the bonding material and the fin increases, and as a result, the connection between the fin and the base plate is increased. The strength can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a specific example of the present invention.

FIG. 2 is a schematic diagram showing a specific example of a heat sink from the top surface side.

FIG. 3 is a schematic view showing an arrangement relationship between a mounting concave portion and a solder in the heat sink of the specific example.

FIG. 4 is a schematic view showing a specific example in which a weir is provided on a base plate.

FIG. 5 is a schematic view showing a specific example in which a base plate has a heat pipe structure.

FIG. 6 is a schematic view showing a specific example provided with a mounting cover.

FIG. 7 is a schematic view showing a mounting cover.

FIG. 8 is a schematic view showing a specific example provided with a plated portion made of Cu plating.

FIG. 9 is a schematic diagram showing a specific example provided with a plated portion made of solder plating.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heat sink, 2 ... Base plate, 3 ... Fin unit, 4 ... Mounting recessed part, 5 ... Fin, 6 ... Base surface part, 7 ... Top surface part, 8 ... Side surface part, 9 ... Solder,
10, 16 ... dam part, 11 ... container, 14 ... mounting cover, 18 ... plating part.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akihiro Takamiya 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Ivan Saucheck 1-5-1, Kiba, Koto-ku, Tokyo F-term in Fujikura (reference) 5F036 AA01 BA23 BB01 BB05 BB60

Claims (2)

[Claims] In a heat sink including a base plate provided at a heat exchange target portion that generates or absorbs heat and a large number of fins erected on the base plate, a bonding material that solidifies to provide an adhesive function is attached to the base plate. A heat sink, comprising: a weir portion for holding the fin in a predetermined range on a surface, and integrally connected with one end of the fin inserted into the bonding material. 2. Each of the fins has a spread in a surface direction of the base plate, and is formed integrally with the base surface in a state where the fin projects from one surface of the base surface as an attachment portion to the base plate. And a unit structure in which one adjacent fin and the base surface are integrally connected, and the other adjacent fin and the tip of the protrusion are integrally connected. The heat sink according to claim 1, wherein: