JP2011129640A - Dimple plate and method of manufacturing the same, and heat radiation plate and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dimple plate and a method of manufacturing the same, and a heat radiation plate and a method of manufacturing the same, enhancing heat conductivity in a thickness direction of a heat radiation plate, of uniformly maintaining heat radiation characteristics in the thickness direction of the heat radiation plate independent of a part of the heat radiation plate, and achieving a heat radiation plate with a large Invar ratio and a low thermal expansion coefficient in a plate surface direction. <P>SOLUTION: A dimple plate 1 has a plurality of dimples 2 formed on a surface of a flat plate 5 in a longitudinal direction and a width direction of the flat plate 5 in a predetermined pitch. In the dimple plate 1, the pitch in a width direction of the dimple 2 is equal to or less than 0.5 mm, and a ratio of an area of a region in which a hole 3 penetrating the flat plate 5 in the bottom part of the dimple 2 is formed, to the superficial area of the flat plate 5, is equal to or less than 15%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dimple plate used for a core of a composite heat radiating plate having low thermal expansion and high thermal conductivity and a method for manufacturing the same, and a heat radiating plate using the same and a method for manufacturing the same. The present invention relates to a dimple plate that can be manufactured at a high speed with improved inferiority, and has high characteristics at a low price, and a manufacturing method thereof, and a heat radiating plate and a manufacturing method thereof.

  Conventionally, expanded metal has been known as a perforated plate or a mesh-like plate, and the standard is defined in JIS-G3351 “Expanded Metals” and applied in various fields.

  The feature of expanded metal is that, unlike punching metal, punching scraps are not produced at the time of manufacture, so that the production yield is good and 100% of the material can be made into a product.

  An example of the expanded metal mesh shape (mesh shape) is shown in FIGS.

  As shown in FIGS. 12A to 12C, the hole 72 of the expanded metal 71 has a rhombus shape or a turtle shape, and the surface and cross section thereof have a shape with a step 73.

  As shown in FIGS. 13A to 13F, in the conventional expanded metal manufacturing method, the wave blade 81 having a wavy blade is disposed on the upper side, and the flat blade 82 is disposed on the lower side. Using the flat blade 82, the flat plate 83 as the material is sequentially cut to form the holes 72, and the perforated plate, that is, the expanded metal 71 is manufactured.

  A conventional expanded metal manufacturing apparatus 80 includes a material feed roller 84 and a cutting device 85, and the cutting device 85 has a wave-shaped wave blade 81 arranged above a flat blade 82 fixed below. Can be moved in the vertical direction and in the horizontal direction (the direction from the back left side to the right side in the figure).

  When the expanded metal 71 is manufactured using the expanded metal manufacturing apparatus 80, first, the flat plate 83 is fed from the material feed roller 84 between the wave blade 81 and the flat blade 82 as shown in FIG. As shown in FIG. 13B, the wave blade 81 is lowered to shear the flat plate 83 between the wave blade 81 and the flat blade 82. At this time, the wave blade 81 is stopped halfway so as not to cut the flat plate 83 completely. Thus, the flat plate 83 is cut at regular intervals, and at the same time, the flat plate 83 is formed into a wave shape (wave shape) of the wave blade 81.

  Then, as shown in FIG. 13 (c), after the wave blade 81 is raised, as shown in FIG. 13 (d), the flat plate 83 is fed by the material feed roller 84 (the feed is made by the material feed roller 84). At the same time, the wave blade 81 is moved in the half pitch (p / 2) lateral direction with respect to the pitch (wave pitch) p of the wave shape. Then, as shown in FIGS. 13E and 13F, similarly, the wave blade 81 is lowered to cut the flat plate 83, and the flat plate 83 is formed into a wave shape.

  Thereafter, the flat plate 83 is again fed by the material feed roller 84, the horizontal position of the wave blade 81 is returned to the original half pitch, and the flat plate 83 is indented at regular intervals, and the flat plate 83 is formed into a wave shape. The expanded metal 71 is manufactured by repeating this continuously. The above is the basic manufacturing method of the expanded metal 71.

Expanding shape of the mesh of metal 71 (mesh) is directly related to its production method, with respect to the thickness T _o of the flat plate 83 which is a material, the mesh of the fine width (step width) W is, material feed roller 84 Is equal to the feed amount (feed pitch) of the flat plate 83, and the connection width of the adjacent holes 72 in the feed direction of the flat plate 83 (the width of the frame around the hole 72) is 2W. The mesh width direction pitch (mountain pitch) L _w is equal to the wave pitch p of the wave blade 81. Further, the longitudinal pitch S _w of the mesh corresponds to the feeding amount of the wave blade 81 (how much the wave blade 81 is lowered during shearing).

As described above, the expanded metal 71 has a good yield when manufacturing a perforated plate and can be efficiently processed, but has a drawback. It is related with the manufacturing method described above, in the conventional expanded metal 71, and with a step 73 on its surface, with respect to the thickness T _o, is that the shape of the large hole 72. That is, in the conventional method of manufacturing expanded metal, with respect to the thickness T _o, it is impossible to produce a finely perforated plates having fine pores 72. In addition, since the knives are added one by one, there is a problem that the manufacturing speed is slow and the processing efficiency is lowered.

JIS-G3351 is generally relative thickness T _o, but pore size (widthwise pitch L _w) is a method of making a porous plate of 10 to 100 times greater net, its porosity is a problem . That is, conventionally, that although the pore size can be manufacture as long as the porous plate of a large network with 10 to 100 times the thickness T _o, to produce the pore size is less finely perforated plates to the plate thickness T _o difficult. The perforated plate having fine pore size, on the order that is described in Non-Patent Document 1, the pore size was more than five times the thickness T _o.

  Here, the hole shape of the expanded metal 71 will be further considered.

The shape of the expanded metal 71 is as shown in FIGS. 12 (a) to 12 (c), and the manufacturing method thereof is a flat blade in which a flat plate 83 is fixed downward as described in FIGS. 13 (a) to (f). A net-like perforated plate, that is, an expanded metal 71 is formed by punching alternately while moving the wave blade 81 disposed on the upper side to the left and right for each pitch (each time the flat plate 83 is fed). However, if you try to shape the expanded metal 71 assigned to the fine pore size of the plate thickness T _o, forming limit exists.

FIG. 14 shows a schematic view of the cut and formed part of the expanded metal 71. In the conventional expanded metal manufacturing method, the flat plate 83 which is a material is cut and formed by the flat blade 82 and the wave blade 81. in the rear (flat blade 82 side) of the molded part of) 91, portions of the flat plate 83 in contact with the end portion 81a of the Namiha 81 and shear fracture pressed into flat blade 82, the hole 72 of width L _h is formed The At this time, a portion (hereinafter referred to as a remaining bridge portion) 92 located in the concave portion of the wave blade 81 of the flat plate 83 remains, and the remaining bridge portion 92 connects the molded portion 91 and the rear flat plate 83.

  The forming portion 91 is subjected to bending deformation by the tip portion (bottom portion) of the wave blade 81. As a result, the hole 72 is formed by shearing. In order to receive bending deformation, the forming portion 91 generates ± yield stress and plastically deforms.

Whether despite the forming limit of the expanded metal 71 of fine pore size in the plate thickness T _o is shear ruptured residual bridge portion 92 of the forming unit 91 rearward (the connecting portion between the molding portion 91 and the rear of the flat plate 83) is generated It depends on what. That is, the molding limit is determined by the magnitude of the shearing force of the remaining bridge portion 92 behind the molding portion 91 and the bending deformation force of the molding portion 91.

The shearing force F _s of the remaining bridge portion 92 on the flat plate 83 side per pitch is expressed by the following equation (1).
F _s = (L _w −L _h ) T _o τ _I (1)
Where L _w : mesh width direction pitch
L _h : width of the hole
T _o: thickness
τ _I : Shear stress of material (flat plate)

Assuming that the bending deformation force of the forming portion 91 per pitch is F _b , the moment M at the bending center portion is expressed by the following equation (2).
M = F _b / 2 × L _h / 2 = F _b × L _h / 4 (2)

  Further, according to Mises' yield condition, the moment M at the center of bending is expressed by equation (3) shown in [Equation 1].

From the equations (2) and (3), the bending deformation force F _b of the forming portion 91 is expressed by the equation (4) shown in [Equation 2].

The condition under which the expanded metal 71 can be normally formed is expressed by the following formula (5).
F _s > F _b (5)

  Therefore, the limit condition is expressed by Expression (6) shown in [Formula 3] when Expressions (1) and (4) are substituted into Expression (5).

Usually, the feed pitch (step width W) is almost equal with the thickness T _o of the flat plate 83, when W = T _o, so that the equation (6) the formula shown in [Expression 4] (7) .

That is, in the conventional method of manufacturing expanded metal, any mesh shape does not mean it is also formed with, have limited thickness T _o of the flat plate 83, the limit value of the thickness T _o of the flat plate 83 the width of the mesh It is proportional to the direction pitch L _w. That is, the width direction pitch L _w of the mesh to be produced small expanded metal 71, the limit value of the thickness T _o of the flat plate 83 becomes small, the plate thickness T _o is large thickness widthwise pitch L of the mesh in the meat material _This means that an expanded metal 71 having a small _w , that is, a fine porous plate cannot be manufactured.

Figure 15, JIS commercially as (JIS commercially available), showing the relationship of commercially available plate thickness T _o and the width direction pitch in the non-patent document 2 expanded metal (fine commercially available) as fine expanded metal is L _w. Also shows limits of the thickness T _o obtained from the above equation (7) to (E limit line). As shown in FIG. 15, both of them has entered into a shape range satisfying the above equation (7), the thickness T _o is or large, is smaller widthwise pitch L _w, i.e. expanded metal having fine pores Is not manufactured.

  In patent document 1, the idea which improves the processing limit (the above-mentioned formula (6) and formula (7)) of the conventional expanded metal is proposed. In Patent Document 1, a measure is taken in which a wavy backer plate that moves in synchronization with the upper wave blade is placed at the end of the cutting flat blade, thereby making it possible to improve the above-described processing limit. ing. However, with this measure, the backup is not complete enough to assist the load force, and a more powerful measure is required.

  Patent Document 2 proposes that the mesh shape is formed in two stages at the same time, and the processing speed is doubled to improve the processing speed, in that the step is fine and the processing speed does not increase. However, there is a need for an order of magnitude improvement in this regard.

  Furthermore, in Patent Document 3, as a method for producing expanded metal in a mass production manner, a method of producing expanded metal using an intermittent slitter and a spreading roll is described in a roll method. Among the products, this is a production method that can be applied only when the pore size is large instead of the thickness, and is not suitable for the production of a fine porous plate.

JP-A-1-127119 JP 2003-33824 A JP 2007-175720 A

Suzuki Technos Co., Ltd., [online], [Search June 19, 2009], Internet <URL: http://www.suzuki-tkns.co.jp/product/expanded/index.html> Cosmo Corporation, [online], [Search June 19, 2009], Internet <URL: http://www.cosmo9.co.jp/zairyo_metal.htm>

  The first problem with the prior art is that the shape of the perforated plate is not suitable for the intended application.

  When a heat sink is produced using an expanded metal made of Invar material for the core, the hole pitch in the width direction becomes larger from the processing limit of the above-mentioned expanded metal, for example, a semiconductor element having a size of about several mm on the heat sink In some cases, the heat generated in the semiconductor element cannot be properly radiated depending on the mounting location of the semiconductor element on the heat sink.

  The problem in the aspect of the manufacturing method is productivity, and the expanded metal has a low processing speed because the knurls are put one by one. There is no problem as long as a large mesh shape is made, but if a microporous plate with a feed pitch (step width) of the order of 1 mm or less is manufactured by this method, it takes a very long time, resulting in an expensive one. End up. In order to manufacture an inexpensive fine porous plate, it is essential to increase the speed. In punching metal, it is possible to punch a perforation with one stroke, but in this case, the yield in production is a problem because of punching waste. Moreover, in the punching metal, the hole entrance is an edge, and it is difficult to ensure the metal flow into the hole.

  Therefore, the object of the present invention is to solve the above problems and provide a structure of a fine porous plate used for a core of a composite heat radiating plate having low thermal expansion and high thermal conductivity and an efficient manufacturing method thereof. A dimple plate having a structure in which the surface high thermal conductivity material easily flows into the core hole when it is made into a composite material while being a small pitch with a small pitch instead of the plate thickness, a manufacturing method thereof, and a heat sink and It is in providing the manufacturing method.

  The present invention has been devised to achieve the above object, and the invention of claim 1 has a plurality of dimples formed on the surface of the flat plate at a predetermined pitch in the longitudinal direction and the width direction of the flat plate. In the dimple plate, the ratio of the area of the region where the pitch in the width direction of the dimple is 0.5 mm or less and the hole penetrating the flat plate is formed at the bottom of the dimple with respect to the surface area of the flat plate Is a dimple plate having 15% or less.

  The invention of claim 2 is a heat radiating plate comprising the dimple plate according to claim 1 and a heat transfer plate which is joined to the surface of the dimple plate and a part of which is filled in the dimple. .

  The invention of claim 3 is provided with a wave blade having a wave-shaped blade in the upper mold and the lower mold, these upper mold and lower mold are arranged to face each other, and a flat plate is fed between the upper mold and the lower mold, A method of manufacturing a dimple plate by pressing the flat plate from above and below with the upper mold wave blade and the lower mold wave blade, and forming the flat plate into a corrugated shape, wherein the upper mold and the lower mold are , Having a multi-stage wave blade composed of stepped wave blades, feeding the flat plate in a stepwise inclined direction of the multi-stage wave blade, pressing the flat plate from above and below with the multi-stage wave blade, and The step of forming a plurality of irregularities with a single stroke of a multi-stage wave blade to form a fine irregularity plate, and the fine irregularities by feeding and rolling the fine irregularity plate between flat rolls arranged vertically opposite to each other. Dimples with flattened surface and dimples on the surface A method for producing a dimple plate and forming a plate.

  According to the invention of claim 4, two multi-stage wave blade rolls having corrugated stepped wave blades are formed on the circumferential surface, and the two multi-stage wave blade rolls are arranged to face each other vertically, and the upper and lower multi-stage waves are arranged. A flat plate is fed between blade rolls, the flat plate is rolled, and the flat plate is sequentially pressed from above and below with the stepped wave blades formed on the multi-stage wave blade roll to continuously form irregularities on the flat plate. A step of forming a fine uneven plate, and a dimple plate having dimples on the surface thereof by flattening the surface of the fine uneven plate by feeding and rolling the fine uneven plate between flat rolls arranged vertically opposite to each other. A dimple plate manufacturing method including a forming step.

  According to a fifth aspect of the present invention, a heat transfer plate is joined to the surface of the dimple plate manufactured by the method for manufacturing a dimple plate according to claim 3 or 4 by clad rolling, and the heat transfer plate is inserted into the dimple. It is a manufacturing method of the heat sink which fills one part.

  According to a sixth aspect of the present invention, the dimple plate is made of a material having a smaller thermal expansion coefficient than the heat transfer plate, and the heat transfer plate is made of a material having a higher thermal conductivity than the dimple plate. It is a manufacturing method of this heat sink.

  According to the dimple plate of the present invention, the heat conductivity in the thickness direction of the heat radiating plate manufactured using this dimple plate is increased, and the heat radiating characteristics in the thickness direction of the heat radiating plate are not dependent on the portion of the heat radiating plate. A heat dissipation plate that can be maintained uniformly, has a large Invar ratio, and has a low coefficient of thermal expansion in the plate surface direction can be realized.

  According to the method for manufacturing a dimple plate of the present invention, it is possible to efficiently manufacture a dimple plate having a structure suitable for a fine porous plate used for a core of a composite heat radiating plate having low thermal expansion and high thermal conductivity. Instead, a dimple plate having a structure in which the surface high thermal conductivity material easily flows into the core hole can be manufactured with high productivity when it is made into a composite material with a small pitch and a small size.

It is a perspective view showing a dimple plate according to an embodiment of the present invention, (a) is a perspective view of a dimple plate with double-sided dimple holes provided with a substantially triangular dimple, and (b) is a substantially hexagonal shape. It is a perspective view of a dimple plate with double-sided dimple holes provided with dimples. It is sectional drawing of the dimple board which concerns on one embodiment of this invention, (a) is a double-sided dimple board, (b) is sectional drawing of a dimple board with a double-sided dimple hole. It is the photograph which shows the external appearance of the dimple board with a double-sided dimple hole, (a) is a photograph of the dimple board with a double-sided dimple hole provided with the substantially triangular dimple, and (b) is the double-sided with the substantially hexagonal dimple. It is a photograph of a dimple plate with dimple holes. (A)-(d) is a figure explaining the manufacturing method of the dimple board which concerns on one embodiment of this invention, and is a figure explaining the process of forming a fine porous uneven | corrugated board by a porous inclination press method. It is a figure explaining the manufacturing method of the dimple board which concerns on one embodiment of this invention, and is a figure explaining the process of forming a fine porous uneven | corrugated board by a porous inclination press method. It is a figure explaining the manufacturing method of the dimple board which concerns on one embodiment of this invention, and is a figure explaining the process of forming a dimple board from a fine porous uneven | corrugated board by flat roll rolling. It is a disassembled perspective view of the heat sink which concerns on one embodiment of this invention. It is a figure explaining the manufacturing method of the dimple board which concerns on one embodiment of this invention, and is a figure explaining the process of forming a fine porous uneven | corrugated board by a porous grooved rolling method. It is a figure explaining the manufacturing process of the dimple board in an Example. In the present invention, it is a diagram illustrating feed pitch W, the width pitch L _w, a length the pitch S _w, the material thickness T _o, or molded plate thickness T ₂ is the length of which part, (a) shows the microporous An uneven plate, (b) is a view showing a dimple plate. The hole shape of the microporous uneven plate of Example is a conventional expanded metal hole shape (the relationship between the thickness T _o and the width direction pitch L _w) as written in the graph showing the forming limits. It is a figure which shows the conventional expanded metal, (a) is a top view, (b) is the enlarged view, (c) is a 12C-12C sectional view taken on the line. (A)-(f) is a figure explaining the manufacturing method of the conventional expanded metal. It is a figure explaining the deformation | transformation state (formation limit) of the conventional expanded metal. It is a graph in which the conventional expanded metal hole shape (relationship thickness T _o and the width direction pitch L _w) showing the forming limit.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, the dimple plate used for the heat sink according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the dimple plate 1 has a plurality of concave dimples (dents and depressions) 2 formed at a predetermined pitch in the longitudinal direction and width direction of the flat plate 5 on the surface of the flat plate 5. Is done. Since the dimple plate 1 has a structure in which a large number of dimples 2 are formed on a flat plate 5, it is also called a microporous plate. Although not shown in FIG. 1, the dimple plate 1 is formed in a long shape, and the above-mentioned longitudinal direction refers to the longitudinal direction in the long shape, and the width direction refers to the width in the long shape. The direction (direction perpendicular to the longitudinal direction). Although the details will be described later, the longitudinal direction is the feeding direction of the flat plate 5 when the dimple plate 1 is manufactured.

  The dimple plate 1 is formed of a material having a thermal expansion coefficient (linear expansion coefficient) smaller than that of the material constituting the heat transfer plate described later, that is, a low thermal expansion material. Specifically, the dimple plate 1 is made of an Invar alloy (Invar alloy) and is composed of a super invar (Super Invar) made of Fe-36 mass% Ni, Fe-36.5 mass% Ni, Fe-32 mass% Ni-5 mass% Co. ) Material, Fe-54 mass% Co-9.5 mass% Cr, or the like.

  The dimple 2 is formed with a thickness smaller than the thickness of the flat plate 5 on which the dimple 2 is formed. In the dimple plate 1, the portion where the dimple 2 is formed is a thin portion. The dimple plate 1 has a plurality of thin portions having a thickness smaller than the plate thickness of the flat plate 5, and the pitch of the thin portions may be equal to or less than a predetermined pitch. The shape of the dimple 2 is concave (that is, , A state in which there is no hole penetrating the dimple plate 1), a hole shape (that is, a form having a hole penetrating the dimple plate 1), and the like.

  Examples of the form of the dimple plate 1 include the following forms.

  A dimple plate 1 a shown in FIG. 2A has a plurality of dimples 2 on the front surface S and also has a plurality of dimples 2 on the back surface R. However, the dimples 2a formed on the front surface S and the dimples 2b formed on the back surface R are isolated by the material constituting the dimple plate 1a. That is, in the dimple plate 1a, the dimple 2a and the dimple 2b are kept separated from each other (hereinafter, the dimple plate 1a as shown in FIG. 2A may be referred to as “double-sided dimple plate 1a”).

  2B has a plurality of dimples 2 on the front surface S and also has a plurality of dimples 2 on the back surface R. The dimple plate 1b shown in FIG. Further, in the dimple plate 1b, the dimple 2a provided on the front surface S and the dimple 2b provided on the back surface R are connected to each other through a hole 3 in the vicinity of the bottom. That is, the dimple 2a and the dimple 2b are connected via the hole 3 penetrating the dimple plate 1b (hereinafter, the dimple plate 1b as shown in FIG. 2B is referred to as “dimple plate 1b with double-sided dimple holes”). Sometimes). FIG. 1 shows the dimple plate 1b with double-sided dimple holes. FIG. 1 (a) shows a dimple plate with double-sided dimple holes 1b having a substantially triangular dimple 2, and FIG. 1 (b) shows a substantially hexagonal shape. A dimple plate 1b with double-sided dimple holes provided with a shaped dimple is shown.

  FIG. 3 is a photograph showing the appearance of the dimple plate 1 (dimple plate 1b with double-sided dimple holes). The shape of the dimple 2 in the plan view of the dimple plate 1 shown in FIG. 3A (hereinafter simply referred to as “dimple plate surface shape”) is substantially triangular. The dimple plate surface shape is not limited to a triangular shape, and may be a shape having an arc such as a circle or an ellipse, or a shape such as a polygon such as a rectangle, a hexagon, or an octagon. FIG. 3B shows a photograph of a dimple plate 1b with double-sided dimple holes provided with a substantially hexagonal dimple 2. FIG. The dimple plate surface shape is preferably a substantially hexagonal shape from the viewpoint of ease of manufacture.

  Further, in the dimple plate 1, for the purpose of ensuring the heat dissipation characteristics of the heat radiating plate, the ratio of the dimple 2 to the surface of the dimple plate 1, that is, the region where the dimple 2 is formed with respect to the surface area of the dimple plate 1. The area ratio (hereinafter sometimes referred to as “dimple occupation ratio”) is preferably 30% or less.

  Furthermore, when the hole 3 is provided in the dimple 2 of the dimple plate 1, it is preferable that the hole 3 occupies an area that is less than half of the area that the dimple 2 occupies on the surface of the dimple plate 1 in plan view. In the dimple plate 1 according to the present embodiment, the area of the hole 3 that penetrates the flat plate 5 at the bottom of the dimple 2 with respect to the surface area of the flat plate 5 (that is, the projected area of the hole 3). Ratio (hereinafter also referred to as “dimple penetration rate”) is 15% or less. The reason why the dimple penetration rate is 15% or less is that if the dimple penetration rate exceeds 15%, the size of the holes 3 is large, and therefore the cross-sectional ratio of the dimple plate 1 in the heat sink (ie, the Invar ratio) is increased. This is because a heat radiating plate having a low coefficient of thermal expansion of the plate surface light cannot be provided. Incidentally, the double-sided dimple plate 1a in which the hole 3 is not formed naturally has a dimple penetration rate of 15% or less.

  By the way, for example, when a semiconductor element having a size of several millimeters is mounted on the heat sink, assuming that the pitch of the dimples 2 (or holes 3) is a predetermined value or more, the semiconductor element is mounted on the heat sink. Depending on the location, the heat generated in the semiconductor element may not be radiated appropriately. That is, unless the pitch of the dimples 2 (or the holes 3) is not fine to some extent, the thermal conductivity in the thickness direction of the heat sink is deteriorated. Therefore, in the present embodiment, each of the plurality of dimples 2 (or holes 3) is provided for the purpose of maintaining the heat transfer characteristics in the thickness direction of the heat sink substantially the same regardless of the portion of the heat sink. In the longitudinal direction and the width direction, for example, the pitch is 1 mm or less, preferably 0.7 mm or less, more preferably 0.5 mm or less, and the pitch is substantially uniform. In particular, when manufacturing a heat sink (clad rolling), the size in the width direction does not change substantially, so the heat conductivity in the thickness direction of the heat sink is kept high and the heat conductivity in the thickness direction is high. In order to make the distribution of the dimples uniform, the pitch in the width direction of the dimples 2 (or holes 3) is formed to be 0.5 mm or less.

  Now, the manufacturing method of the dimple plate 1 is roughly divided into a step of forming a fine concavo-convex plate in which fine unevenness is formed on the flat plate 5, and a step of forming the dimple plate 1 by rolling the fine concavo-convex plate with a flat roll. Consists of.

  Here, prior to describing the method for manufacturing a dimple plate according to the present embodiment, a manufacturing apparatus for a fine uneven plate used in the step of forming the fine uneven plate will be described. Here, as an example, a case where a dimple plate 1b with double-sided dimple holes (see FIG. 2B) is manufactured will be described.

  When the dimple plate 1b with double-sided dimple holes is manufactured, the fine uneven plate has the holes 3 penetrating the flat plate 5. Hereinafter, the fine uneven plate having such holes 3 will be described. Is called a fine porous concavo-convex plate. Similarly, an apparatus for manufacturing a fine porous uneven plate is referred to as a fine porous uneven plate manufacturing apparatus.

  As shown in FIG. 4, the fine porous uneven plate manufacturing apparatus 41 includes a material feed roller (not shown) and a cutting device 42. In the cutting device 42, the upper mold 43 and the lower mold 44 are provided with multi-stage wave blades having a corrugated stepped wave blade, the upper mold 43 and the lower mold 44 are arranged to face each other, and between the upper mold 43 and the lower mold 44, The flat plate 5 as the material is intermittently fed from the material feeding roller at a predetermined cycle.

  As shown in FIG. 5, the upper mold 43 disposed above has a plurality of (five steps in FIG. 5) stepped corrugated blades 6 a to 6 e having corrugated (uneven corrugated corrugated) step blades. Are formed of stepped multi-stage wave blades 6 in the feeding direction of the flat plate 5 so that they are shifted by 1/5 to 1/2 pitch. The step widths of the stepped wave blades 6a to 6e are formed to be equal to the step width W of the fine porous uneven plate 45 to be manufactured.

  In addition, the lower die 44 disposed below, like the upper die 43, has a plurality of (five steps in FIG. 5) stepped corrugated blades 7a to 7e having corrugated (uneven corrugated corrugated) step blades. It consists of stepped multi-stage wave blades 7 in the feeding direction of the flat plate 5 so that the eye shape is shifted by 1/5 to 1/2 pitch.

  In the present embodiment, the case where the multi-stage wave blades 6 and 7 are five-stage wave blades 6a to 6e and 7a to 7e will be described, but the number of step wave blades is not limited thereto.

  In the present embodiment, in order to manufacture the dimple plate 1 made of Invar alloy, the flat plate 5 made of Invar alloy is used. However, the material of the flat plate 5 is not particularly defined and basically A ductile metal material such as copper, aluminum, iron, titanium, nickel, niobium, gold, silver, Invar (Fe-36Ni), or an alloy thereof may be used. Further, not only metals but also plastics and ceramic molding materials can be processed as long as they are ductile materials. That is, although the case where the dimple board 1 used for a heat sink is manufactured is demonstrated here, the use of the dimple board 1 manufactured with the manufacturing method of the dimple board of this invention is not limited to this, For various uses It is possible to use.

  Next, a method for manufacturing a dimple plate according to the present embodiment will be described.

  In the dimple plate manufacturing method according to the present embodiment, first, as shown in FIG. 4A, the flat plate 5 that is a processed material by the material feed roller is placed between the upper mold 43 and the lower mold 44 ( In other words, the multi-stage wave blades 6 and 7 are fed into the stepwise inclined direction of the multi-stage wave blades 6 and 7 (in the direction from the upper right to the lower left in FIG. 4A), and as shown in FIG. 5 is pressed (fitted) from above and below with multi-stage wave blades 6 and 7.

  The state of deformation during pressing is shown in detail in FIG. FIG. 5 shows an upper die 43, a lower die 44, and a fine porous uneven plate 45 (deformed portion of the flat plate 5) formed thereby, and the upper and lower multi-stage wave blades 6 and 7 are opened, and the flat plate 5 and the flat plate 5 are shown. The fine porous uneven | corrugated board 45 shape | molded in a part of is shown.

  As shown in FIG. 5, the flat plate 5 disposed between the upper and lower multi-stage wave blades 6 and 7 is processed by pressing the upper multi-stage wave blade 6 against the lower multi-stage wave blade 7.

  At this time, the bending deformed portion 8a is formed by pressing the opposed upper and lower stepped wave blades 6a and 7a, and the shearing portion 9a is formed by pressing the stepped wave blades 6a and 7b. Similarly, bending deformed portions 8b to 8e are sequentially formed by pressing the stepped wave blades 6b and 7b, 6c and 7c, 6d and 7d, and 6e and 7e. By the pressing, the shear deformed portions 9b to 9d are sequentially formed.

  In the bending deformation portions 8a to 8e, bending deformation is performed by transferring the wave shape of the upper and lower multi-stage wave blades 6 and 7, whereas in the shear deformation portions 9a to 9d, the stepped wave blades 6a and 7b, 6b and 7c, An uneven knitted structure including unevenness (thin wall portion) to be dimples 2 and voids 3 is formed by shearing between 6c and 7d, 6d and 7e (shear on the side surface of the stepped wave blades 6a to 6d on the stepped wave blade 6e side). As a result, a fine porous uneven plate 45 is formed.

  Thereafter, as shown in FIG. 4C, when unloading / releasing is performed, molding for one stroke is completed. After the formation of the first stroke, as shown in FIG. 4 (d), the flat plate 5 is fed by one stroke, and as shown in FIG. 4 (d), the second stroke is formed in the same manner as the first stroke. I do. By repeating this, an infinitely long fine porous uneven plate 45 is obtained.

  As described above, in the present embodiment, the flat plate 5 is pressed from above and below with the multi-stage wave blades 6 and 7, and a plurality of irregularities are formed on the flat plate 5 by one stroke of the multi-stage wave blades 6 and 7, so A plate 45 is formed. Hereinafter, such a processing method of the fine porous uneven plate 45 is referred to as a porous inclined press method. The obtained microporous uneven plate 45 is thicker than the flat plate 5 before processing because convex portions are formed on the surface.

  When forming the double-sided dimple plate 1a (see FIG. 2A) that does not form the air holes 3, the stepped wave blades 6a to 6e and 7a to 7e have gaps (to the extent that the flat plate 5 is not sheared). (Interval) may be provided.

  After the fine porous uneven plate 45 is formed by the fine porous uneven plate manufacturing apparatus 41, the fine porous uneven plate 45 is fed between the flat rolls 46 opposed to each other as shown in FIG. Roll. Thereby, the convex part formed in the surface of the fine porous uneven | corrugated board 45 is smooth | blunted and planarized, and plate | board thickness is returned to the original raw material thickness (thickness of the flat plate 5). Thus, the dimple plate 1 having the dimple 2 formed on the surface is obtained. In FIG. 6, the holes 3 of the dimple 1 are omitted for simplification of the drawing.

  The pitch of the obtained dimple plate 1 in the width direction matches the pitch of the corrugated shape of the stepped wave blades 6a to 6e, 7a to 7e, but the pitch in the longitudinal direction corresponds to the length of the dimple ratio corresponding to the length of the dimple 2. It will be extended.

  Here, the reason why the fine dimples or microporosity can be achieved by the dimple plate manufacturing method according to the present embodiment will be described.

In the present embodiment, the flat plate 5 is formed with wave blades (stepped wave blades 6a to 6e, 7a to 7e). At this time, the flat plate 5 inserted between the stepped corrugated blades 6a and 7a is sandwiched between the stepped corrugated blade 6a and the stepped corrugated blade 7a, bent and deformed, and the wave shape of the stepped corrugated blades 6a and 7a is transferred and molded. The bending deformation force F _f generated at this time is the same as the expression (4) in the conventional expanded metal, and is expressed by the expression (8) shown in [Equation 5].

The flat plate 5 side of the formed part is perforated by shear deformation, and the load at that time is given by the stepped wave blades 6a and 7b, and the shear force (load force) F _h is the formula (1) in the conventional expanded metal. And is represented by the following formula (9).
F _h = F _s = (L _w −L _h ) T _o τ _I (9)

In immediately after the start of shearing, the width L _h of the holes are close to zero, is a load _{F h = L w T o τ} I, the hole is large, the load of the formula (9).

Eventually, the force F _w applied to the first stepped wave blade 7a is expressed by the following equation (10).
F _w = F _f + F _h (10)

The manufacturing method of the dimple plate according to the present embodiment is a forming method using a multi-hole inclined press method, that is, a forming method using a multistage method, and the bending deformation force F _f for forming is a stepped wave blade in the first step below. Since the load is applied by 7a, the corresponding force is not applied to the flat plate 5 side of the forming portion (the connecting portion between the forming portion and the rear flat plate 5), the limit condition is not satisfied, and the force is stable. A reticulated shaped product can be formed.

  Similarly, formulas (8) to (10) are also established between the stepped wave blades 6b and 7b and between the stepped wave blades 6b and 7c. The same applies to the subsequent modifications.

  If n-stage molding is performed with one stroke, the stroke becomes longer by that amount, but the load is constant and does not change. Further, there is no fear of breaking at the mesh connecting portion (remaining bridge portion), and the processing speed is increased n times.

In the conventional method of manufacturing expanded metal, there is a processing limit as described in FIG. 15, the thick material, but porous material of small pore pitch L _w than E limit line is impossible production, the present invention In the multi-stage molding method, there is no such limit.

  Next, the heat sink according to the present embodiment will be described. Here, a heat radiating plate using the dimple plate 1b with double-sided dimple holes shown in FIG.

  The heat radiating plate according to the present embodiment includes a dimple plate 1 and a heat transfer plate that is bonded to the surface of the dimple plate 1 and partially filled in the dimple 2.

  The dimple plate is made of a material having a smaller thermal expansion coefficient than that of the heat transfer plate, and here, made of an Invar alloy. The heat transfer plate is made of a material having a higher thermal conductivity than the dimple plate 1, and is made of, for example, copper or a copper alloy, or aluminum or an aluminum alloy. In this embodiment, copper is used as the heat transfer plate.

  As shown in FIG. 7, the heat sink 100 according to the present embodiment is formed in a CIC structure in which a dimple plate 1 made of Invar alloy is sandwiched between heat transfer plates 14 made of copper.

  The heat transfer plate 14a arranged on the surface S side of the dimple plate 1 is joined to the surface S of the dimple plate 1, and is filled in the dimple 2a formed on the surface S side, and joined to the surface in the dimple 2a. Is done.

  Similarly, the heat transfer plate 14b disposed on the back surface R side of the dimple plate 1 is joined to the back surface R of the dimple plate 1 and filled in the dimple 2b formed on the back surface R side. Bonded to the surface.

  Further, the two heat transfer plates 14 a and 14 b are joined to each other through the air holes 3. In FIG. 7, the holes 3 are omitted for simplification of the drawing.

The heat sink 100 thus obtained has a thermal conductivity of 150 (W / ° C. · m) or more in the thickness direction and a thermal expansion coefficient of 1 in the plate surface direction at a thickness of 1 mm or more. It is possible to realize a thick heat radiating plate 100 having a low thermal expansion and high thermal conductivity of 2 × 10 ⁻⁵ (1 / K) or less and sufficiently usable as a heat sink material or the like.

  In the heat radiating plate 100, a dimple plate 1b having double-sided dimple holes (see FIG. 2B) is used as the dimple plate 1. The heat transfer plate 14 is provided on both the front surface S-side dimple 2a and the rear surface R-side dimple 2b. Therefore, the bonding area between the dimple 2 and the heat transfer plate 14 can be increased and the bonding strength can be increased. The same effect can be obtained by using a double-sided dimple plate 1a (see FIG. 2A) as the dimple plate 1.

  When manufacturing the heat sink 100, the dimple plate 1 is sandwiched between the heat transfer plates 14a and 14b and clad rolled. Then, the heat transfer plates 14a and 14b are bonded to the front and back surfaces of the dimple plate 1, and the material constituting the heat transfer plate 14a flows into the dimple 2a and is bonded to the surface of the dimple 2a. The material constituting the hot plate 14b flows into the dimple 2b and is joined to the surface inside the dimple 2b. Further, the material constituting the heat transfer plate 14a flowing into the dimple 2a on the front surface S side and the material constituting the heat transfer plate 14b flowing into the dimple 2b on the back surface R side are joined to each other through the holes 3, The heat transfer plates 14a and 14b are joined to each other through the air holes 3, and the heat radiating plate 100 is obtained.

  As described above, in the dimple plate 1 according to the present embodiment, the pitch in the width direction of the dimple 2 is 0.5 mm or less, and penetrates the flat plate 5 at the bottom of the dimple 2 with respect to the surface area of the flat plate 5. The area ratio of the region where the holes 3 are formed is 15% or less.

  Since the pitch in the width direction does not change during clad rolling, the pitch in the width direction of the dimple 2 in the dimple plate 1 is set to 0.5 mm or less, so that when the heat sink 100 is manufactured using the dimple plate 1. The heat conductivity in the thickness direction of the heat sink 100 can be increased, and the heat dissipation characteristics in the thickness direction of the heat sink 100 can be maintained uniformly regardless of the portion of the heat sink 100.

  Further, the ratio of the area of the area where the hole 3 penetrating the flat plate 5 is formed at the bottom of the dimple 2 to the surface area of the flat plate 5 is set to 15% or less, thereby reducing the size of the hole 3. It is possible to reduce the cross section ratio of the dimples 2 in the heat sink 100, that is, the Invar ratio, and to realize the heat sink 100 having a low coefficient of thermal expansion in the plate surface direction.

  Moreover, in the manufacturing method of the dimple plate according to the present embodiment, the upper mold 43 and the lower mold 44 are formed by using the stepped wave blades 6a to 6e and 7a to 7e by the stepped multistage wave blades 6 and 7, and the flat plate 5 is formed. The multi-stage wave blades 6 and 7 are fed in a stepwise inclined direction, and the flat plate 5 is pressed from above and below by the multi-stage wave blades 6 and 7, so that a plurality of irregularities are formed on the flat plate 5 by one stroke of the multi-stage wave blades 6 and 7. The surface of the fine porous uneven plate 45 is flattened by forming the fine porous uneven plate 45 and rolling the fine porous uneven plate 45 between the flat rolls 46 arranged vertically opposite to each other. And a step of forming a dimple plate 1 having dimples 2 on the surface.

  Although composite heat sinks such as Cu / Invar alloy / Al material having good thermal conductivity in the thickness direction have an idea than before, they are still not used on the commercial level. This is because an Invar perforated plate suitable for a heat sink and an expanded metal cannot be manufactured. Expanded metal has a manufacturing limit in the first place, and a required shape itself cannot be manufactured at a commercial level.

  In the present invention, the expanded metal manufacturing method is basically improved, and it becomes possible to manufacture the dimple plate 1 (micro perforated plate) with a fine pitch instead of the plate thickness, without reducing the plate thickness of the dimple plate 1. Microporosity or micro unevenness can be achieved.

  In other words, according to the present invention, it is effective in terms of shape stability, and in the conventional expanded metal manufacturing method, when a thick material is processed, the connecting portion of the mesh is cut by shear deformation, so that molding is performed. It has been described that there is a limit to the processing of the product, and it can only be formed within the wall thickness range equal to or greater than the E limit line in FIG. 15. However, the manufacturing method of the present invention has no such limitation and cannot be processed by the conventional technology. Even with a thick material, it is possible to mold the dimple plate 1 with a fine pitch.

  Since the dimple plate 1 formed using a low thermal expansion material is thick and has a fine structure, it is possible to obtain a heat dissipation plate 100 having a low thermal expansion and high thermal conductivity suitable as a heat sink material, and its application effect is great. . Furthermore, according to the present invention, when the heat sink 100 is manufactured as a composite material, the heat transfer plate 14 which is a surface high heat conductive material has a porous structure dimple plate 1 in which metal flow easily occurs in the holes 3. Is obtained. In other words, according to the present invention, the dimple plate 1 having a minute hole (hole 3) that has a large number of fine dimples 2 on a strong flat plate 5 and is easy to flow metal in the thickness direction during metal composite. realizable.

  Moreover, according to the present invention, not only is it effective in terms of shape stability, but it is also effective in terms of productivity. In contrast to the conventional manufacturing method that uses a wave blade and a flat blade to cut one line at a time, in this embodiment, the multi-stage includes stepped wave blades 6a to 6e and 7a to 7e having a thickness corresponding to the step width W. Using the wave blades 6 and 7, the multi-stage wave blades 6 and 7 are formed with multiple strokes in one stroke, and the processing speed is double the number of stepped wave blades 6a to 6e and 7a to 7e used, Manufacturing with extremely high productivity is possible.

  For example, the length that can be formed in one stroke can be improved by 50 times by using it as multi-stage wave blades 6 and 7 having 50 stepped wave blades 6a to 6e and 7a to 7e, and the processing speed is also high at that ratio. Can be This effect is particularly significant with the fine pitch dimple plate 1 (fine porous plate), which is less productive with the prior art, and the same effect can be expected with large size products.

  Next, another embodiment of the present invention will be described.

  In the above embodiment, the case where the dimple plate 1 having the dimple 2 having the fine porous bottom wall thickness is manufactured by forming the fine porous uneven plate 45 by the porous inclined press method has been described. 45 can also be formed by rolling. Hereinafter, a method of forming the fine porous concavo-convex plate 45 by rolling is referred to as a porous grooving rolling method.

  In the porous grooving rolling method, the fine porous uneven plate 45 is formed by using a fine porous uneven plate manufacturing apparatus 51 as shown in FIG.

  The microporous uneven plate manufacturing apparatus 51 forms two multi-stage wave blade rolls 52, 53 in which stepped wave blades 52a, 53a having wave-shaped blades on a circumferential surface are formed in a stepwise manner, and these Two multi-stage wave blade rolls 52 and 53 are arranged opposite to each other in the vertical direction.

  That is, the microporous uneven plate manufacturing apparatus 51 is a multistage wave blade roll in which the stepped multistage wave blades 6 and 7 in the microporous uneven plate manufacturing apparatus 41 described with reference to FIGS. 52 and 53 are opposed to each other in the vertical direction, and by rolling in a state where the upper and lower multi-stage wave blade rolls 52 and 53 are fitted, the microporous uneven plate 45 similar to FIG. 5 can be formed. .

  When forming the fine porous uneven plate 45 using the fine porous uneven plate manufacturing apparatus 51, the flat plate 5 is fed between the upper and lower multi-stage wave blade rolls 52, 53, and the flat plate 5 is moved to the multi-stage wave blade rolls 52, 53. The formed stepped corrugated blades 52a and 53a are sequentially pressed from above and below to form the unevenness continuously on the flat plate 5 to form the fine porous uneven plate 45.

  By pressing the upper stepped wave blade 52a against the lower stepped wave blade 53a, the flat plate 5 inserted therebetween is processed, and a bending deformation portion is formed by pressing the upper and lower stepped wave blades 52a and 53a. The shear deformation portion 9 is formed by pressing the blade 52a and the stepped wave blade 53a below the next step. As described above, the fine porous uneven plate 45 can be manufactured by the rolling method.

  The microporous dimple plate 1 can be manufactured by rolling the obtained microporous uneven plate 45 with a flat roll 46 as in FIG.

  In the perforated grooving and rolling method, as in the case of the perforated inclined press method described above, bending deformation by bending and deformation of thinned perforations by shear deformation are placed next to each other, and these can be performed alternately to form a fine porous uneven plate 45. It is said. It is important that the gap between the upper and lower stepped wave blades 52a and 53a of the shearing portion is 5/100 mm or less.

  Even in the perforated grooving and rolling method, the fine perforated uneven plate 45 can be formed and the dimple plate 1 can be manufactured as in the perforated inclined press method. However, in terms of productivity, the work can be performed completely continuously. The porous grooving and rolling method that can increase the processing speed is more efficient. On the other hand, in terms of dimensional accuracy, the perforated inclined press method is better. Therefore, any processing method may be selected according to the application.

  In carrying out the present invention, a manufacturing process of the dimple plate 1 is shown in FIG.

  As shown in FIG. 9, the flat plate (material flat plate) 5 is first processed into a fine porous uneven plate 45 by a porous inclined press or porous grooving rolling, and then smoothed and rolled to obtain fine porous dimples. It is referred to as a plate 1.

  As the material flat plate 5, Invar alloy (Fe-36 mass% Ni) was used as the material, and flat plates having thicknesses of 0.2 mm and 0.3 mm and a width of 50 mm were used.

  As for the perforated inclined press method, a manufacturing apparatus 41 for fine porous uneven plate shown in FIGS. 4 and 5 is used, and the pitch in the longitudinal direction of the stepped corrugated blade is 0.2 mm. , 7 (upper mold 43, lower mold 44). Therefore, 10 mm can be formed in one stroke, and continuous molding can be performed by inserting a 10 mm material feed in each step in the stepwise inclined direction of the multi-stage wave blades 6, 7. The fine porous uneven plate 45 could be formed. By pressing the multi-stage wave blades 6, 7, the molding thickness is about twice that of the flat plate 5, and it is rolled with a flat roll 46 as shown in FIG. 6 to the original material thickness (thickness of the flat plate 5). At the same time, the irregularities on the surface were smoothed to produce a microporous dimple plate 1.

  In the multi-grooved rolling method, multi-stage wave blade rolls 52 and 53 having multi-stage wave blades having the same width direction, longitudinal pitch and the same wave shape as the multi-stage wave blades 6 and 7 of the porous inclined press method are manufactured. Thereby, grooving and piercing roll rolling were performed. As the multi-stage wave blade rolls 52 and 53, those having an outer diameter of 50 mm, a pitch of 0.2 mm in the circumferential direction and 785 stepped wave blades were used. By using the multi-stage wave blade rolls 52 and 53, a mesh-like fine porous concavo-convex plate 45 was manufactured, and subsequently, the flat roll 46 shown in FIG. 6 was rolled to manufacture the fine porous dimple plate 1.

Table 1 shows a result of comparison between the microporous uneven plate 45, the dimple plate 1 (Example), and the conventional expanded microporous plate (conventional example) manufactured by the porous inclined press method and the porous grooved rolling method of the present invention. Indicates. Incidentally, the feed pitch W in Table 1, the width pitch L _w, a length the pitch S _w, the material thickness T _o, whether the length of which part is molded plate thickness T _2, FIG. 10 (a), (b) It shows.

As shown in Table 1, in the example of the present invention, a plate 5 made of Invar alloy having a thickness as thick as 0.2 mm and 0.3 mm is used, and a wave blade pitch (width pitch L _w ) is 0.5 mm. Even when the size of the microporous uneven plate 45 and the dimple plate 1 were stable, the microporous uneven plate 45 and the dimple plate 1 having the required dimensions could be formed.

  On the other hand, in the conventional example using the conventional expanding molding, the connecting portion (connecting portion) is cut and normal molding is impossible.

  Compared with the conventional expanded metal product size (FIG. 15), FIG. 11 shows the data (product of the present invention) of the microporous uneven plate 45 produced according to the present invention. As shown in FIG. 11, according to the present invention, it can be seen that normal molding is possible even in a region beyond the E limit line. In the conventional example using the expand molding, a size exceeding the E limit line, which is the processing limit, cannot be realized as calculated.

  Thus, according to the present invention, it is possible to form the dimple plate 1 with a fine pitch even if it is a thick material that cannot be processed by the prior art. In the present embodiment, the case where the multi-stage wave blades 6 and 7 having 50 stepped wave blades are used in the pressing method and the multi-stage wave blade rolls 52 and 53 of φ50 mm are used in the rolling method has been described. The size is not specified, and it can be further increased to increase productivity.

  Next, using the dimple plate 1 made of an Invar alloy manufactured by the method for manufacturing a dimple plate of the present invention, a heat radiating plate 100 was manufactured and its characteristics were evaluated.

As shown in FIG. 7, a dimple plate 1 having a width pitch L _w = 0.5 mm and a forming plate thickness T ₂ = 0.2 mm is sandwiched from above and below by a heat transfer plate 14 made of Cu having a thickness of 0.2 mm. Clad rolling was performed to manufacture a heat sink 100 having a CIC structure.

  Specifically, after cold rolling at a workability of about 70%, diffusion heat treatment was performed at about 600 ° C. so as not to form an intermetallic compound at the interface between the Invar alloy and Cu. As a result, the heat transfer plates 14 arranged vertically are joined in the air holes 3 of the dimple plate 1. The final thickness of the heat sink 100 was 0.2 mm.

  Furthermore, as an application example, the dimple plate 1 has a fine pitch, the heat transfer plate 14 is thinned, and the finished thickness is changed without changing the processing degree of about 70%. A heat sink 100 was prototyped. The conditions in the example are that the area ratio (dimple penetration rate) of the holes 3 in the dimple plate 1 is 15% or less, and at the same time, the hole pitch (width direction) is 0.5 mm or less.

  Further, as a comparative example, a dimple plate having a dimple penetration rate exceeding 15% or a dimple plate having a hole pitch (width direction) exceeding 0.5 mm is manufactured, and a heat dissipation plate using the dimple plate is manufactured. The characteristics were investigated.

  Table 2 shows the configurations and characteristic measurement results of the examples and comparative examples.

As shown in Table 2, allowable conditions were set regarding the thermal expansion coefficient in the plate surface direction, the thermal conductivity in the thickness direction, and local uniformity. The allowable conditions are that the thermal expansion coefficient in the plate direction is 1.2 × 10 ⁻⁵ (1 / K) or less, and the thermal conductivity in the thickness direction is 170 (W / ° C. · m) or more. As for the local uniformity, a fine distribution of electrical resistance in the thickness direction was measured as a characteristic value to simulate the thermal conductivity, and the evaluation of local uniformity was evaluated as “◯” or “X”.

  As a result, both the examples and the comparative examples satisfied the allowable conditions for the thermal conductivity in the thickness direction. Moreover, as for the thermal expansion coefficient in the plate surface direction and the characteristics of local uniformity, all of the examples satisfied the allowable conditions. In particular, the heat sink 100 using the dimple plate 1 having a pitch of 0.35 mm in Example C1 was particularly good in local uniformity and was evaluated as a double circle.

In the comparative example, either the thermal expansion coefficient in the plate surface direction or the local uniformity characteristic did not satisfy the allowable condition. In Comparative Examples H1 and H3 in which the hole pitch is increased to 0.7 mm, both the local uniformity is insufficient and there is a portion where the electric resistance is locally increased, and the thermal conductivity distribution in the thickness direction is predicted not to be uniform. Is done. In Comparative Examples H2 and H3 in which the dimple penetration rate is larger than 15%, the dimple ratio is increased as a result, the Invar ratio in the heat sink is decreased, and the thermal expansion coefficient in the plate surface direction is 1.4 × 10. ^-5 (1 / K) or more and the allowable conditions were not satisfied.

  From the above, in order to obtain the heat radiating plate 100 satisfying both the thermal expansion coefficient in the plate surface direction, the thermal conductivity in the thickness direction, and the local uniformity, the pitch of the holes 3 is not more than 0.5 mm. It is necessary to use the dimple plate 1 having an area ratio (dimple penetration rate) of 15% or less.

1 Dimple plate 2 Dimple 3 Air hole 5 Flat plate

Claims (6)

In the dimple plate having a plurality of dimples formed on the surface of the flat plate at a predetermined pitch in the longitudinal direction and the width direction of the flat plate,
The pitch of the dimples in the width direction is 0.5 mm or less, and the ratio of the area of the area where the holes penetrating the flat plate are formed at the bottom of the dimple is 15% or less with respect to the surface area of the flat plate A dimple plate characterized by being.   A heat radiating plate comprising: the dimple plate according to claim 1; and a heat transfer plate which is bonded to a surface of the dimple plate and partially filled in the dimple. A wave blade having a wave-shaped blade is provided in the upper die and the lower die, the upper die and the lower die are arranged to face each other, a flat plate is fed between the upper die and the lower die, and the flat plate is attached to the upper die. A method for producing a dimple plate by pressing from above and below with a wave blade and a wave blade of the lower mold, and forming the flat plate into a wave shape,
The upper mold and the lower mold have multi-stage wave blades composed of stepped corrugated blades, feed the flat plate in the stepwise inclined direction of the multi-stage wave blades, and press the flat plate from above and below with the multi-stage wave blades. A step of forming a plurality of irregularities on the flat plate with a single stroke of the multi-stage wave blade to form a fine irregular plate;
Providing the dimple plate having dimples on the surface thereof by flattening the surface of the fine concavo-convex plate by rolling the fine concavo-convex plate between flat rolls arranged vertically opposite to each other and rolling. A manufacturing method of a dimple plate characterized by the above. Two multi-stage corrugated blade rolls having corrugated stepped corrugated blades are formed on the circumferential surface, and these two multi-stage corrugated blade rolls are arranged facing each other vertically, and a flat plate is fed between the upper and lower multi-stage corrugated blade rolls. The step of rolling the flat plate and pressing the flat plate from above and below with the stepped corrugated blades formed on the multi-stage corrugated blade roll to form irregularities on the flat plate to form a fine uneven plate. When,
Providing the dimple plate having dimples on the surface thereof by flattening the surface of the fine concavo-convex plate by rolling the fine concavo-convex plate between flat rolls arranged vertically opposite to each other and rolling. A manufacturing method of a dimple plate characterized by the above.   A heat transfer plate is joined to the surface of the dimple plate manufactured by the method for manufacturing a dimple plate according to claim 3 or 4 by clad rolling, and a part of the heat transfer plate is filled in the dimple. A method for manufacturing a heat sink. The dimple plate is made of a material having a smaller thermal expansion coefficient than the heat transfer plate,
The method of manufacturing a heat sink according to claim 5, wherein the heat transfer plate is made of a material having a higher thermal conductivity than the dimple plate.

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