JP2006261239A - Manufacturing method of printed wiring board with cooling layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a printed wiring board with a cooling circuit for allowing a coolant such as water to circulate. <P>SOLUTION: The manufacturing method of a printed wiring board with cooling layer including a coolant flowing route containing layer formed with a built-in coolant circulating route comprises a cooling circuit forming step as a first step, to form a cooling circuit with half-etching process of the surface of the coolant flowing route containing board, a laminating step to form a laminated body by laminating the surface of the coolant flowing route containing board forming the coolant circuit in contact with an insulating layer forming material, and a conductor circuit forming step to form the printed wiring board with a cooling layer by finally forming the conductor circuit through etching process of the surface of the coolant flowing route containing board. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The invention according to the present application relates to a method for manufacturing a printed wiring board including a cooling layer or a cooling circuit through which a coolant such as water can flow.

  In recent years, various electronic devices such as computer devices have been spreading worldwide, and their supply speed is remarkable. In general, electronic devices represented by such computers are concentrated in urban areas in developed countries.

  And in that urban area, with the emergence of high-rise buildings, it becomes an area where it is difficult for the wind to pass in the physical sense, and it is said to be one of the factors of the heat island phenomenon that raises the average temperature in that area. On the other hand, it is also said that heat generated from a large amount of OA equipment such as computers accelerates the heat island phenomenon, which in turn contributes to global warming.

  In addition, heat generated from OA equipment such as a computer may be heat generated by circuit resistance when the printed wiring board is energized, heat generated from a mounted component such as an IC chip mounted on the printed wiring board, and the like. It has been pointed out that the temperature is quite high. With the recent increase in computing speed of computers, the clock frequency generally exceeds 3 GHz, and the amount of generated heat tends to increase. If the material which comprises a printed wiring board is grasped | ascertained, it will be a composite material of a metal material and a plastic material, and it is clear that there is a certain limit in order to improve the heat resistance.

  Therefore, in most electronic devices, in order to discharge the amount of generated heat to the outside, as shown in the drawing of Patent Document 1, a means for attaching a flat fan to a case of the electronic device or the like to lower the temperature inside the case. Is usually adopted.

  In recent years, heat generated from the printed wiring board is not discharged to the outside using a flat fan, but the printed wiring board is cooled by water cooling as disclosed in Non-Patent Document 1. Attempts have been made.

JP 2001-115993 A Nikkei Business Daily (issued January 29, 2005)

  However, at this stage, even if a layer that can be cooled using a refrigerant is provided in any layer of the printed wiring board, the most suitable layer structure and design as a printed wiring board is clear. Not.

  In the process of manufacturing a printed wiring board, no research has been conducted on how efficiently a printed wiring board with a cooling layer can be manufactured in an industrial level production.

  From the above, there is a need in the market for a method for manufacturing a printed wiring board with a cooling layer that has a design with excellent cooling effect, can be used as it is, and has excellent mass productivity. It was.

1st manufacturing method: It is a manufacturing method of the printed wiring board with a cooling layer which concerns on this invention, Comprising: It is a manufacturing method of the printed wiring board with a cooling layer containing the refrigerant | coolant flow path built-in layer which incorporated the flow path through which a refrigerant | coolant can flow. Thus, the following steps a to e are performed. Such a printed wiring board with a cooling layer includes a conductor circuit layer and a refrigerant flow path built-in layer on one side.

Step a: A first etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate, an etching pattern is exposed on the etching resist layer, and developed.
Step b: A cooling circuit forming step of half-etching the refrigerant flow path built-in plate to remove the etching resist pattern and form a cooling circuit.
Step c: A laminating step in which the surface of the refrigerant flow path built-in plate on which the cooling circuit is formed is laminated so as to come into contact with the insulating layer constituent material to form a laminated laminate.
Step d: A second etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate of the laminate, the etching pattern is exposed to the etching resist layer, and developed.
Step e: Conductor circuit forming step of etching the surface of the refrigerant flow path built-in plate, peeling off the etching resist pattern to form a conductor circuit, and forming a printed wiring board with a cooling layer.

Second manufacturing method: A method for manufacturing a printed wiring board with a cooling layer according to the present invention, the manufacturing method for a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow. Thus, the following steps a to e are performed. Such a printed wiring board with a cooling layer includes a conductor circuit layer and a refrigerant flow path built-in layer on one side.

Step a: A first etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate, an etching pattern is exposed on the etching resist layer, and developed.
Step b: Conductor circuit forming step of half-etching the refrigerant flow path built-in plate, peeling off the etching resist pattern, and forming a conductor circuit.
Step c: A laminating step in which the surface of the refrigerant flow path built-in plate on which the conductor circuit is formed is laminated so as to abut against the insulating layer constituting material to form a laminated laminate.
Step d: A second etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate of the laminate, the etching pattern is exposed to the etching resist layer, and developed.
Step e: A cooling circuit forming step in which the surface of the refrigerant flow path built-in plate is etched, the etching resist pattern is peeled off to form a cooling circuit, and a printed wiring board with a cooling layer is formed.

Third manufacturing method: A method for manufacturing a printed wiring board with a cooling layer according to the present invention, the manufacturing method for a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow. It is characterized by going through the following steps a to c. Such a printed wiring board with a cooling layer is characterized by including a conductor circuit layer on one side and a refrigerant flow path built-in layer on the opposite side.

Step a: A laminating step in which the refrigerant flow path built-in plate, the insulating layer constituent material, and the conductor layer are sequentially laminated and bonded together.
Step b: An etching resist pattern forming step in which an etching resist layer is provided on the surface of the conductor layer, the etching pattern is exposed to the etching resist layer, and developed.
Step c: A circuit forming step in which the conductor layer is etched to remove the etching resist pattern.

Fourth manufacturing method: A method for manufacturing a printed wiring board with a cooling layer according to the present invention, the manufacturing method for a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow. It is characterized by going through the following steps a to c. Such a printed wiring board with a cooling layer is characterized in that it includes a conductor circuit layer on one side and a refrigerant flow path built-in layer on the opposite side.

Step a: A laminating step in which the refrigerant flow path built-in plate, the insulating layer constituent material, and the conductor layer are sequentially laminated and bonded together.
Step b: An etching resist pattern forming step in which an etching resist layer is provided on each surface of the conductor layer and the refrigerant flow path built-in plate, the etching pattern is exposed to the etching resist layer, and developed.
Step c: A circuit formation step in which the conductor layer is etched to form a circuit shape, and at the same time, the coolant channel built-in plate is etched to form a cooling circuit, and the etching resist pattern is peeled off.

  The refrigerant flow path built-in plate used in each of the manufacturing methods described above uses a first metal plate having a recess forming surface having a plurality of recesses on one surface side, and a second metal plate having smooth both surfaces, It is preferable to use what is obtained by bonding the second metal plate to the concave surface of the metal plate.

  Further, the refrigerant flow path built-in plate used in the method for manufacturing a printed wiring board with a cooling layer according to the present invention has a plurality of slit holes formed between the first metal plate and the second metal plate having smooth surfaces. It is also preferable to use what is obtained by sandwiching three metal plates.

  And it is also preferable to use the refrigerant | coolant flow path built-in board used with the manufacturing method of the printed wiring board with a cooling layer concerning the said this invention which half-etched the single side | surface, and formed the heat radiation fin shape beforehand.

  The refrigerant flow path built-in plate used in the method for manufacturing a printed wiring board with a cooling layer according to the present invention preferably includes a dissimilar metal layer made of nickel, tin, aluminum, titanium, and an alloy thereof in the layer. . It becomes easy to manufacture a heat radiation fin shape and the like.

  Furthermore, it is preferable that the inner wall surface of the flow path built in the refrigerant flow path built-in layer is provided with a rust prevention treatment layer.

  The manufacturing method of the printed wiring board with a cooling layer described above is basically described as a manufacturing method for processing a printed wiring board on the basis of a double-sided laminated board. The printed wiring board with a cooling layer obtained by these manufacturing methods is provided with a cooling layer or a cooling circuit that has not been conventionally used, and enables cooling of the printed wiring board by a water cooling method.

  And it is also easy to manufacture a multilayer printed wiring board using the above-mentioned technical idea. For example, if a general multilayer printed wiring board manufacturing method is adopted and the insulating layer of the printed wiring board with a cooling layer obtained by the manufacturing method according to the present invention includes an inner core material, the cooling layer An attached multilayer printed wiring board can be obtained. In addition, a general multilayer printed wiring board manufacturing method is adopted, and the printed wiring board with cooling layer according to the present invention is used as an inner layer core material, and a multilayer printed wiring board with cooling layer in which a circuit is formed on the outer layer. It is also possible to obtain.

  In the case of a multilayer printed wiring board, an interlayer conduction means that electrically connects the inner layer circuit and a circuit located in the outer layer, or an interlayer conduction means as a heat radiation path, such as a conventional through hole, via hole, etc. It is also possible to form by applying a forming method.

  In the printed wiring board with a cooling layer according to the present invention, it is easy to provide a layer that can be cooled using a refrigerant in the layer of the printed wiring board using a conventional printed wiring board manufacturing process. And since the printed wiring board itself can be directly cooled by the refrigerant, it is possible to efficiently remove the amount of generated heat even if further high-density mounting is performed, which can greatly contribute to downsizing of electronic devices and the like. . Further, even if the amount of heat generated from a single power supply circuit is large, the amount of generated heat can be quickly eliminated, so that the width of the power supply circuit can be reduced.

  Embodiments relating to a method for producing a printed wiring board with a cooling layer according to the present invention will be described below. For convenience of explanation, a refrigerant flow passage built-in layer that will first constitute a refrigerant flow passage built-in layer used in the production method will be described. The manufacturing method and type of the plate will be described.

Refrigerant channel built-in plate: Here, for convenience of explanation, a plate-like material used to constitute the refrigerant channel built-in layer of the printed wiring board with a cooling layer according to the present invention is referred to as a refrigerant channel built-in plate. There are roughly two types of manufacturing methods for the refrigerant flow path built-in plate. Strictly speaking, there are four types of forms as the final refrigerant flow path built-in plate. Accordingly, these will be described as the refrigerant flow path built-in plate (I) to the refrigerant flow path built-in plate (IV).

Refrigerant flow path built-in plate (I): As shown in FIG. 1, this refrigerant flow path built-in plate (I) includes a first metal plate 11 having a plurality of recesses on one side and a recess forming surface, and both surfaces are smooth. The second metal plate 12 is used and rolled in a state of being laminated as shown in FIGS. 1 (a-1) and (a-2). As a result, the second metal plate 12 is clad on the recess forming surface of the first metal plate 11, and the refrigerant flow path built-in plate including the flow path 2 shown in FIGS. 1 (b-1) and 1 (b-2) ( I) 10 is obtained.

  The recess forming surface of the first metal plate 11 at this time may be formed by forming an etching resist layer on the surface of the first metal plate 11, exposing and developing a desired etching resist pattern, and half-etching. desirable. In addition, it is desirable to form an etching resist layer on the entire surface of the first metal plate 11 opposite to the recess forming surface to prevent etching from the opposite surface. The half-etching mentioned here refers to etching in which a portion of the first metal plate without an etching resist is completely dissolved and a through hole is not formed, but a recess is formed. There is no particular limitation on the cross-sectional shape of the concave portion referred to here, and it is possible to adopt any shape such as a straight shape, a meandering shape, a herringbone shape, etc., as the manner of running of the concave portion in the plane of the first metal plate 11. At this time, the depth of the recess is preferably 20 μm or more. More preferably, it is in the range of 200 μm to 1000 μm. If it is less than 20 μm, variations occur in the cross-sectional shape of the flow path formed by bonding by the rolling method described below. Even if the depth of the recess exceeds 1000 μm, there is no practical problem, but the total thickness of the refrigerant flow path built-in plate increases, the weight load increases, and the processing cost of the recess increases.

  Then, the second metal plate 12 is clad by the rolling method on the recess forming surface of the first metal plate 11 manufactured as described above. The following conditions are used for the clad rolling conditions at this time. It is preferable. It is preferable to mainly use copper or a copper alloy for the first metal plate and the second metal plate. This is because it has excellent thermal conductivity and is inexpensive. Therefore, as the copper alloy, the alloy numbers shown in JIS H 3100 are C1000 series and C2000 series copper alloys, brass, free-cutting brass, tinned brass, admiralty brass, naval brass, aluminum bronze, bronze, etc. it can.

  And it is preferable that the thickness of a 1st metal plate and a 2nd metal plate shall be the range of 35 micrometers-1100 micrometers. If the thickness is less than 35 μm, sufficient strength and corrosion resistance cannot be obtained, and if the thickness exceeds 1100 μm, it becomes heavier, increasing the labor load during handling, leading to an increase in the weight of the final electronic device. And the 2nd metal plate forms the recessed part for forming a flow path. Therefore, the refrigerant flow path built-in plate (I) obtained by bonding the first metal plate and the second metal plate has a total thickness in the range of 70 μm to 2.2 mm.

When rolling and bonding the first metal plate and the second metal plate, it is preferable to perform activation treatment on at least one of the first metal plate and the second metal plate. In this activation treatment, at least one of the first metal plate and the second metal plate is loaded in a vacuum chamber, and these metal plates are used as grounded electrodes, and 10 to 1 between the other insulated and supported electrodes. A glow discharge is performed by applying an alternating current of 1 to 50 MHz in an extremely low pressure inert gas atmosphere of × 10 ⁻³ Pa, and the surface of the metal plate is sputter-etched in plasma generated by the glow discharge. preferable.

  Then, both metal plates are bonded together by rolling. Rolling in such a case can be performed at a low temperature and a low rolling rate, and adverse effects such as structural changes, alloying, fracture, etc. occurring in the vicinity of the metal plate and the joining interface caused by hot welding or high rolling rate welding. It can be reduced or eliminated. Moreover, it is possible to reduce the deformation of the concave portion of the second metal plate, and the flow path can be processed with high accuracy. It is preferable that the processing temperature of the first metal plate and the second metal plate at the time of the rolling joining is 300 ° C. or less. More preferably, the temperature is higher than 0 ° C. and is in the range of 300 ° C. or lower. Rolling lamination at a temperature of 0 ° C. or lower is possible, but a significant investment in equipment such as a cooling device is required. On the other hand, when it exceeds 300 ° C., the joint becomes brittle and the joint strength is lowered. The rolling rate is preferably 30% or less. More preferably, a rolling rate of 0.1% to 30% is adopted. If the rolling rate is less than 0.1%, sufficient bonding strength cannot be obtained, and if the rolling rate exceeds 30%, the deformation becomes undesirably large.

  It is also preferable to use a plate having a dissimilar metal layer on one or both of the first metal plate and the second metal plate used for constituting the refrigerant flow path built-in plate (I). That is, the dissimilar metal layer 13 exists in the layer of the refrigerant flow path built-in plate as in the cross-sectional configuration shown in FIG. The dissimilar metal layer is preferably made of a material that can be selectively etched with the metal components constituting the first metal plate and the second metal plate. For example, assuming that the main metal component constituting the first metal plate and the second metal plate is copper, the component constituting the dissimilar metal layer is composed of nickel, tin, aluminum, titanium and alloys thereof. It is preferable. Any of a plate material, a foil material, plating, and dry film formation can be applied as the shape of the dissimilar metal. When copper is removed by etching with an alkaline etching solution, the dissimilar metal layer can remain without being etched as shown in FIG. 1 (a-2), and only the dissimilar metal layer can be left and only copper can be left. This is because it is also possible to etch. This selective etching characteristic is extremely effective when a laminated body including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow is etched to form a radiation fin shape or the like. These will be described later. In FIG. 2, as a variation of the refrigerant flow path built-in plate (I), some of the refrigerant flow path built-in plate (I) having no different metal layer and the refrigerant flow path built-in plate (I) having the different metal layer 13 are shown. Illustrated.

Refrigerant flow path built-in plate (II): As shown in FIG. 3A, the refrigerant flow path built-in plate (II) 10 is provided between the first metal plate 11 ′ and the second metal plate 12 having smooth surfaces. In addition, the third metal plate 14 having a plurality of slit holes processed is sandwiched and clad and bonded together by a rolling method, and the flow path 2 shown as a schematic cross-sectional view in FIG. When such a manufacturing method is employed, the materials of the first metal plate 11 ', the second metal plate 12, and the third metal plate 14 can be changed. Therefore, it is possible to reduce the weight of the printed wiring board as the final product by using only the first metal plate 11 ′ and the second metal plate 12 using a lightweight aluminum material.

  The plurality of slit holes provided in the third metal plate 14 at this time penetrated by forming an etching resist layer on the surface of the third metal plate 14, exposing and developing a desired etching resist pattern, and performing half-etching processing. It is desirable to form slit holes. When forming this slit hole, it is necessary to prevent the slit hole from being formed at the edge of the third metal plate. In addition, in order to form the slit hole which penetrated, you may etch from the one surface side of the 3rd metal plate 14, or may etch simultaneously from both surfaces. In the case of etching from one surface side of the third metal plate 13, it is desirable to form an etching resist layer on the entire opposite surface to prevent etching from the opposite surface. And as for how the slit hole runs in the plane of the third metal plate 13, it is possible to adopt an arbitrary shape such as a straight shape, a meandering shape, a herringbone shape. Furthermore, when forming the slit hole which is a through-hole, if the width | variety of the slit hole to form is 100 micrometers or more, you may process by a punching method. If a slit hole having a width of less than 100 μm is to be formed by the punching method, the processing becomes difficult, and the third metal plate 14 is distorted, or the punching accuracy is inferior.

  The first metal plate 11 / third metal plate 13 / second metal plate 12 manufactured as described above are clad by a rolling method. The clad rolling conditions at this time are the same conditions as described above. Is preferably adopted. Further, when the lamination by the rolling method is completed, the edge portion is cut and removed, and the refrigerant flow path built-in plate (II) 10 is obtained.

  It is also preferable to use a plate having a dissimilar metal layer on one or both of the first metal plate and the second metal plate used for constituting the refrigerant flow path built-in plate (II). That is, the dissimilar metal layer 13 exists in the layer of the refrigerant flow path built-in plate as shown in the cross-sectional configuration shown in FIG. The configuration of the dissimilar metal layer and the like are the same as in the case of the refrigerant flow path built-in plate (I), and thus the description thereof is omitted here. In FIG. 4, as a variation of the refrigerant flow path built-in plate (II), some of the refrigerant flow path built-in plate (II) having no different metal layer and the refrigerant flow path built-in plate (II) having the different metal layer 13 are shown. Illustrated.

Refrigerant channel built-in plate (III): This refrigerant channel built-in plate (III) is the refrigerant channel built-in plate (I) or refrigerant channel built-in plate (II) shown in FIGS. 1 (b) and 3 (b). One surface side is provided with a radiating fin shape.

  This refrigerant flow path built-in plate (III) includes a first metal plate 11 having a concave portion forming surface having a plurality of concave portions on one surface side, and a concave portion forming the flow path 2, and a second surface that is smooth on both surfaces. It can be obtained by using a metal plate 12 and rolling and laminating them in a laminated state.

  Further, as shown in FIG. 5 (a), an etching resist layer is formed on the surface on one side of the refrigerant flow path built-in plate (I) or the refrigerant flow path built-in plate (II), exposed, developed, and subjected to desired etching. By forming the resist pattern 15 and performing half-etching to form the shape of the radiation fin 16, the refrigerant flow path built-in plate (III) 10 whose schematic cross section is shown in FIG. 5B is obtained. In addition, when half-etching one surface of the refrigerant flow path built-in plate (I), it is desirable to form an etching resist layer on the entire opposite surface to prevent etching from the opposite surface. The shape of the radiating fin here is not particularly limited, and the running shape in the plane of the refrigerant flow path built-in plate (I) can adopt any shape such as a straight shape, a meandering shape, and a herringbone shape. In addition, in FIG. 5, the case where the said refrigerant | coolant flow path built-in board (I) was used was illustrated.

Refrigerant channel built-in plate (IV): This refrigerant channel built-in plate (IV) is either the refrigerant channel built-in plate (I) or the refrigerant channel built-in plate (II), and the first metal plate 11 and As shown in FIG. 6 (a), using the one in which the dissimilar metal layer is present in at least one layer with the second metal plate 12, as shown in FIG. The shape of the radiation fin 16 can be formed by forming an etching resist layer on the surface, exposing and developing a desired etching resist pattern 15 and selectively etching up to the dissimilar metal layer 13. In addition, it is not necessary to strictly manage the selective etching time at this time. This is because the dissimilar metal layer 13 is present, thereby preventing further etching progress. FIG. 7 illustrates some of the refrigerant channel built-in plates (IV) including the different metal layer 13 and the heat radiation fins 16 as variations of the refrigerant channel built-in plate (IV).

  And it is preferable to use the said refrigerant | coolant flow path built-in board (I)-refrigerant | coolant flow path built-in board (IV) as a thing provided with the antirust process layer in the inner wall face of the refrigerant flow path. Any of inorganic rust prevention and organic rust prevention may be used for the rust prevention treatment layer at this time. And there is no special limitation also about the formation method of a rust prevention process layer. For example, when performing inorganic rust prevention, the catalyst or solution is allowed to flow into the refrigerant flow path, the catalyst metal such as palladium is adsorbed on the inner wall surface, and then an electroless plating solution such as zinc or tin is allowed to flow, It is also possible to employ a method of forming an inorganic rust prevention treatment layer on the inner wall surface. The organic rust prevention treatment referred to here is a case where a benzotriazole-based organic rust prevention coating is formed on the inner wall surface of the refrigerant flow path or a resin coating layer provided on the inner surface of a beverage can. It is also assumed that an antirust treatment layer is provided on the inner wall surface of the party outside by flowing an organic agent or a coating agent into the flow path. The level of the rust prevention treatment at this time can be changed depending on the application, and the treatment according to the design quality is appropriately selected and used. In the drawing, the description of the antirust treatment layer is omitted. Hereinafter, the manufacturing method of the printed wiring board with a cooling layer which concerns on this invention using the above-mentioned board | substrate with a built-in refrigerant flow path is demonstrated.

(First manufacturing method)
In the case of manufacturing a printed wiring board with a cooling layer according to the present invention, which includes a conductor circuit layer and a refrigerant flow path built-in layer on one side, a flow path with a built-in refrigerant flow path is provided. A method of manufacturing a printed wiring board including a cooling layer or a cooling circuit layer by etching a laminate including a layer, which includes the following steps a to e. This manufacturing method assumes that the above-mentioned refrigerant flow path built-in plate (I) and refrigerant flow path built-in plate (II) are used. Hereinafter, although the process of this 1st manufacturing method is demonstrated for every process, when the refrigerant | coolant flow path built-in board (I) and the refrigerant flow path built-in board (II) without a different metal layer are used for FIGS. FIG. 11 to FIG. 13 show the case where the refrigerant flow path built-in plate (I) and the refrigerant flow path built-in plate (II) having different metal layers are used.

Step a: In this first etching resist pattern forming step, an etching resist layer is provided on the surface of the refrigerant flow path built-in plate, and the etching resist layer is exposed and developed. That is, this is a registration step for providing the etching resist pattern 15 as shown in FIG. 8B on the surface of the refrigerant flow path built-in plate (I) 10 shown in FIG. This process is the same in FIGS. 11A and 11B in the case where the dissimilar metal layer is included inside the refrigerant flow path built-in plate. The etching resist here is not particularly limited, and a dry film, a liquid resist, or the like can be used. Also, the method for exposure and development is arbitrary. In addition, by providing an etching resist layer on the opposite surface of the refrigerant flow path built-in plate and leaving the etching resist layer on the entire surface, damage from the opposite surface of the refrigerant flow path built-in plate can be prevented.

Step b: In this cooling circuit forming step, the refrigerant flow path built-in plate (I) 10 is half-etched, the etching resist pattern is peeled off, and the cooling circuit 3 is formed as shown in FIG. 8C. . Therefore, the half etching at this time is an etching process at such a level that the passage 2 is included in the cooling circuit 3. When the refrigerant flow path built-in plate (I) or the refrigerant flow path built-in plate (II) having a pattern including a different metal layer on one side is used, as shown in FIG. By half-etching from the side where the metal layer 13 does not exist, it is possible to easily manufacture a cooling circuit shape up to the height of the dissimilar metal layer. If a different metal layer is present, an etching solution should be selectively used so that the different metal layer does not dissolve. For example, when nickel as a dissimilar metal layer is present in the copper bulk of the refrigerant flow path built-in plate, an alkaline copper etching solution is used. As can be seen from these figures, the cooling circuit 3 can be provided only for a region where the circuit generates a large amount of heat or a portion corresponding to a circuit that generates a large amount of heat. It is.

Step c: In this laminating step, as shown in FIGS. 9 (d) and 12 (d), the surface of the refrigerant flow path built-in plate (I) 10 in which the cooling circuit 3 is formed is replaced with an insulating layer constituent material. 4 is laminated so as to be in contact with 4, and hot pressing is performed to form a laminate 5 in the manner of manufacturing a copper-clad laminate as shown in FIGS. 9 (e) and 12 (e). In this case, any insulating layer may be used as long as it can be used for the insulating layer of a printed wiring board such as a prepreg or a resin film. Further, the surface of the refrigerant flow path built-in plate on which the cooling circuit 3 is formed before the hot pressing is subjected to roughening treatment such as so-called blackening treatment and roughening etching treatment in advance so as to adhere to the insulating layer. It is also preferable to improve the property.

Step d: In this second etching resist pattern forming step, an etching resist layer is provided on the surface of the refrigerant flow path built-in layer 10A of the laminate 5, and the etching pattern 15 is exposed and developed on the etching resist layer. 9 (f) and 12 (f). Since the concept regarding the etching resist layer at this time is the same as that described above, description thereof is omitted here.

Step e: In the conductor circuit forming step, as shown in FIGS. 10G and 13G, the surface of the refrigerant flow path built-in plate (I) 10 is etched to form the etching resist pattern 15. The conductor circuit 7 is formed by peeling. When the refrigerant flow path built-in plate (I) or the refrigerant flow path built-in plate (II) without the different metal layer 13 is used, the printed wiring board 1 with the cooling layer in which the conductor circuit 7 protrudes from the substrate surface is obtained at this stage.

  However, when the refrigerant flow path built-in plate (I) or the refrigerant flow path built-in plate (II) having a different metal layer on one side is used, the different metal for removing the different metal layer exposed between the circuits. By additionally providing the removing step, as shown in FIG. 13 (h), the printed wiring board 1 with a cooling layer protruding from the surface of the conductor circuit 7 substrate is obtained.

(Second manufacturing method)
In the case of manufacturing a printed wiring board with a cooling layer according to the present invention, which includes a conductor circuit layer and a refrigerant flow path built-in layer on one side, a flow path with a built-in refrigerant flow path is provided. A method of manufacturing a printed wiring board including a cooling layer or a cooling circuit layer by etching a laminate including a layer, which includes the following steps a to e. This manufacturing method assumes that the above-mentioned refrigerant flow path built-in plate (I) and refrigerant flow path built-in plate (II) are used. Hereinafter, although the process of this 1st manufacturing method is demonstrated for every process, when the refrigerant flow path built-in board (I) and refrigerant flow path built-in board (II) without a different metal layer are used for FIGS. 17 to 19 show the case where the refrigerant flow path built-in plate (I) and the refrigerant flow path built-in plate (II) having different metal layers are used. The biggest difference from the first manufacturing method is that the bonding method when the refrigerant flow path built-in plate is bonded to the insulating layer is different.

Step a: In this first etching resist pattern forming step, an etching resist layer is provided on the surface of the refrigerant flow path built-in plate (I) 10 shown in FIGS. 14A and 17A, and the etching resist layer Then, as shown in FIGS. 14B and 17B, the etching resist pattern 15 is exposed and developed. However, in this second manufacturing method, since the conductor circuit shape is formed first, the etching resist pattern 15 formed here is for forming a conductor circuit. Note that the concept relating to the etching resist and the like is the same as described above, and thus the description thereof is omitted here.

Step b: In this conductor circuit forming step, the refrigerant flow path built-in plate (I) 10 is half-etched, and the etching resist pattern 15 is peeled off. As shown in FIGS. 14 (c) and 17 (c), the conductor is formed. A circuit 7 is formed. In addition, since the concept regarding half-etching is the same as that described above, description thereof is omitted here.

Step c: In this laminating step, the surface of the refrigerant flow path built-in plate (I) 10 on which the conductor circuit 7 is formed is brought into contact with the insulating layer constituting material 4 as shown in FIGS. 15 (d) and 18 (d). Thus, it is set as the laminated body 5 shown to FIG.15 (e) and FIG.18 (e) in the point which manufactures a copper clad laminated board by hot-pressing. At this time, the concept of the material used for the structure of the insulating layer is as described above. Further, the surface of the refrigerant flow path built-in plate (I) 10 on which the conductor circuit 7 is formed before the hot pressing is subjected to a roughening process such as a so-called blackening process or a roughening etching process in advance to provide insulation. It is also preferable to improve the adhesion to the layer.

Step d: In the second etching resist pattern forming step, an etching resist layer is provided on the surface of the refrigerant flow path built-in plate (I) 10 of the laminate 5, the etching resist layer is exposed and developed, The state shown in FIG. 15 (f) and FIG. 18 (f) is assumed. Since the concept regarding the etching resist layer at this time is the same as that described above, description thereof is omitted here.

Step e: In the cooling circuit forming step, as shown in FIGS. 16G and 19G, the surface of the refrigerant flow path built-in plate (I) 10 is etched to form the etching resist pattern 15. The cooling circuit 3 is formed by peeling. In this case using the refrigerant flow path built-in plate (I) or the refrigerant flow path built-in plate (II) having no different metal layer, the printed wiring board 1 with the cooling layer in which the cooling circuit 3 protrudes from the substrate surface is obtained at this stage.

  However, when the refrigerant flow path built-in plate (I) or the refrigerant flow path built-in plate (II) having a different metal layer on one side is used, the different metal for removing the different metal layer exposed between the circuits. By additionally providing the removing step, as shown in FIG. 19 (h), the printed wiring board 1 with the cooling layer in which the cooling circuit 3 protrudes from the substrate surface is obtained. As described above, the cooling circuit in a state in which the cooling circuit protrudes from the surface functions as a heat radiating fin and has excellent heat dissipation.

(Third production method)
The method for manufacturing a printed wiring board with a cooling layer according to the present invention obtains a printed wiring board including a cooling circuit layer by etching a laminate including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow. The manufacturing method for this is characterized by including a conductor circuit layer on one side and a refrigerant flow path built-in layer on the opposite side through the following steps a to c. Hereinafter, the case where the refrigerant flow path built-in plate (I) is used will be described as an example, and each process will be described mainly using FIGS. 20 to 22.

Step a: In this laminating step, the refrigerant flow path built-in plate, the insulating layer constituting material, and the conductor layer are sequentially laminated and bonded together. That is, as shown in FIG. 20 (a), the refrigerant flow path built-in plate (I) 10, the insulating layer constituting material 4, and the conductor layer 8 are overlapped and hot-pressed to obtain a copper-clad laminate. Is a laminated body 5 shown in FIG. At this time, the insulating layer 6 may be formed of any insulating layer constituent material that can be used for the configuration of the insulating layer of a printed wiring board such as a prepreg or a resin film. And since metal foil, such as copper foil and nickel foil, is used for the conductor layer 8, there is no limitation in particular. Furthermore, any of the above-described refrigerant channel built-in plate (I) to refrigerant channel built-in plate (IV) may be used as the refrigerant channel built-in plate used for the configuration of the refrigerant channel built-in layer used here. In the drawing, the explanation is made using the refrigerant flow path built-in plate (I).

Step b: In the etching resist pattern forming step in the first manufacturing method, an etching resist layer is provided on the surface of the conductor layer 8, and the etching resist layer is exposed and developed, as shown in FIG. An etching resist pattern 15 is formed. The etching resist here is not particularly limited, and a dry film, a liquid resist, or the like can be used. Also, the method for exposure and development is arbitrary. Note that an etching resist layer is also provided on the surface of the refrigerant flow path built-in layer, and the etching resist layer on the entire surface is left to prevent damage to the refrigerant flow path built-in layer due to the etching solution.

Step c: In this circuit formation step, only the conductor layer 8 is etched and the etching resist pattern is peeled off to form the conductor circuit 7 according to the product design as shown in FIG. It becomes the printed wiring board 1 with a cooling layer satisfying general structural requirements. The refrigerant flow path built-in layer at this time is flat.

  Here, a printed wiring board with a cooling layer having a different cross-sectional shape is used depending on which of the refrigerant flow path built-in plate (I) to the refrigerant flow path built-in plate (IV) is used for the configuration of the refrigerant flow path built-in layer. For example, when the refrigerant flow path built-in plate (II) is used, a printed wiring board with a cooling layer 1 shown in FIG. When the refrigerant flow path built-in plate (III) is used, a printed wiring board with a cooling layer having a protruding shape that functions as the heat radiating fins 16 shown in FIG. When the refrigerant flow path built-in plate (IV) is used, as shown in FIG. 22C, the printed wiring board 1 with the cooling layer having the different metal layer 13 and the protruding shape functioning as the heat radiating fins 16 is obtained. The printed wiring board with a cooling layer having these various layer configurations can be used as a printed wiring board even in this state.

(Fourth manufacturing method)
The method for manufacturing a printed wiring board with a cooling layer according to the present invention is a method for manufacturing a printed wiring board including a cooling circuit layer by etching a laminate including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow. The method is characterized by including a conductor circuit layer on one side and a refrigerant flow path built-in layer on the opposite side through the following steps a to c. Hereinafter, it demonstrates for every process. In the fourth manufacturing method, the refrigerant channel built-in plate (I) or the refrigerant channel built-in plate (II) is used for the configuration of the refrigerant channel built-in layer. Hereinafter, although the process of this 4th manufacturing method is demonstrated for every process, when the refrigerant | coolant flow path built-in board (I) and the refrigerant flow path built-in board (II) without a different metal layer are used for FIG.23 and FIG.24 FIG. 25 and FIG. 26 show the case where the refrigerant flow path built-in plate (I) and the refrigerant flow path built-in plate (II) having different metal layers are used. In the drawings, the description is given using the refrigerant flow path built-in plate (I).

Step a: This laminating step is similar to the third manufacturing method, as shown in FIG. 23 (a) or FIG. 25 (a), the refrigerant flow path built-in plate (I) 10, the insulating layer constituting material 4, and the conductor layer. 8 are sequentially laminated and bonded together by hot pressing to obtain a state of the laminated body 5 shown in FIG. 23 (b) or FIG. 25 (b). Since this laminating process is the same as that in FIGS. 20A and 20B of the third manufacturing method, a detailed description thereof is omitted here.

Step b: In the etching resist pattern forming step of the fourth manufacturing method, an etching resist layer is provided on each surface of the conductor layer 8 and the refrigerant flow path built-in layer 10A, the etching pattern is exposed to the etching resist layer, developed, As shown in FIG. 24 (c-1), FIG. 24 (c-2), or FIG. 26 (c), an etching resist pattern 15 is formed. That is, in the second manufacturing method, the etching resist pattern 15 for positively performing the etching process is formed also on the refrigerant flow path built-in plate. The concept of the etching resist pattern is as described above. 24 (c-1) shows an etching resist pattern for forming a cooling circuit simultaneously with the conductor circuit, and FIG. 24 (c-2) shows an etching resist pattern for forming a heat radiation fin simultaneously with the conductor circuit. Show.

Step c: In this etching step, as shown in FIG. 24 (d-1), FIG. 24 (d-2) or FIG. 26 (d), the conductor layer is etched to form a circuit shape, and at the same time, the refrigerant flow The path built-in plate (I) 10 is etched to form the cooling circuit 3 or the heat radiating fins 16, and the etching resist pattern is peeled off. Here, as can be seen, FIG. 24D-1 shows the cooling circuit 3 formed, and FIG. 24D-2 shows the heat radiation fin 16 formed. Therefore, the thickness of the conductor layer, the material of the conductor layer, the thickness of the refrigerant flow path built-in layer, etc. are designed depending on whether the cooling circuit is formed or the heat radiation fin shape is formed in the etching time for forming the conductor circuit. There is a need. For example, if it is going to obtain the printed wiring board 1 with a cooling layer of FIG.24 (d-1) and the material of the whole board | substrate with a built-in refrigerant flow path is copper and a conductor layer is also copper, a board with a refrigerant flow path built-in and copper. And the same thickness must be designed. In addition, if a metal component constituting the conductor layer having a slower etching rate than copper is employed, a thin conductor layer can be formed. However, when trying to obtain the printed wiring board 1 with a cooling layer shown in FIG. 24D-2, only the shape of the radiating fin is formed, and it is not necessary to etch the entire thickness of the refrigerant flow path built-in board. In addition, a thin conductor layer 8 corresponding to the height of the radiation fin is provided. In addition, when trying to obtain the printed wiring board 1 with a cooling layer shown in FIG. 26 (d), the relationship that the thickness from the surface of the refrigerant flow path built-in plate to the dissimilar metal layer is thinner than the conductor layer 8 is established. If you do. This is because etching is not performed beyond the dissimilar metal layer of the refrigerant flow path built-in plate (I) 10. The printed wiring board 1 with a cooling layer is obtained as described above.

(Manufacturing method of multilayer printed wiring board)
Although what was obtained by the manufacturing method of the printed wiring board with a cooling layer described above is what is called a single-sided or double-sided printed wiring board, a multilayer printed wiring board can be manufactured using these. For example, the printed wiring board with a cooling layer obtained by the manufacturing method according to the present invention is used as an inner layer core material of a multilayer printed wiring board, or another printed wiring board and the printed wiring with the cooling layer via an insulating layer constituent material A method of laminating the boards to form a multilayer printed wiring board is conceivable.

  Moreover, when employ | adopting the said 3rd manufacturing method and 4th manufacturing method, a multilayer printed wiring board can be easily manufactured by including an inner-layer core material in the insulating layer. And the manufacturing method of the printed wiring board with a cooling layer characterized by providing the interlayer conduction | electrical_connection formation process between the process a in the manufacturing method in any one of the said 3rd manufacturing method and the 4th manufacturing method, and the process b. It is preferable to adopt. The interlayer conduction step referred to here is a step of providing interlayer conduction means such as a through hole and a via hole, and a widely known method can be widely used. The production of this multilayer board will be described in detail through the following examples.

  In this example, a printed wiring board with a cooling layer was manufactured using the above-described refrigerant flow path built-in plate (I) using the above-described first manufacturing method. Hereinafter, description will be made mainly with reference to FIGS.

Step a: In this first etching resist pattern forming step, a dry film as shown in FIG. 8B is laminated on the surface of the refrigerant flow path built-in plate (I) 10 shown in FIG. The pattern was exposed and developed to provide an etching resist pattern 15. It should be noted that an etching resist layer made of dry film is provided on the opposite surface of the refrigerant flow path built-in plate (I) 10 to leave the entire surface of the etching resist layer, thereby damaging the etching liquid from the opposite surface of the refrigerant flow path built-in plate. Can be prevented.

  The refrigerant flow path built-in plate (I) 10 used here was manufactured as follows. A copper plate having a thickness of 200 μm is used as the first metal plate. A copper plate having a thickness of 400 μm was used as the second metal plate. Then, an etching resist layer was provided on both sides of a 400 μm thick copper plate. Then, the etching pattern for forming the recessed part 19 in the said etching resist layer of one side was exposed and developed. The entire surface of the etching resist layer on the other side was cured to protect the entire surface from the etching solution. Then, using a copper chloride etchant, half etching was performed from one side to form a linear concave portion having a depth of 150 μm and a width of 50 μm to 250 μm to obtain a second metal plate.

Next, an alternating current of 13.56 MHz is applied to the surface used for joining the first metal plate and the recess forming surface of the second metal plate in an extremely low pressure argon gas atmosphere of 3 × 10 ⁻³ Pa to glow Let the discharge occur,
Activation processing of both joint surfaces was performed. And the 1st metal plate 12 and the 2nd metal plate 11 which activated the joint surface were laminated-rolled as shown to Fig.1 (a), and it bonded together as shown in FIG.1 (b). The rolling rate at this time was 1% under low pressure and room temperature. As a result, the refrigerant flow path built-in plate (I) 10 had a total thickness of 600 μm and had an open area of 150 μ × 50 μm to 250 μm. And the electroless nickel layer was provided as an antirust process layer in the inner wall surface of this flow path. In forming this rust-proofing layer, first, a palladium catalyst solution was caused to flow into the flow path into the flow path, and catalyst adsorption was performed on the inner wall in the flow path. Thereafter, an electroless nickel plating solution was allowed to flow into the flow path, and an electroless nickel plating layer having a thickness of about 3 μm was formed as a rust prevention treatment layer.

Step b: In this cooling circuit forming step, the refrigerant flow path built-in plate (I) 10 on which the etching resist pattern is formed in the step a is half-etched with a copper chloride etchant to obtain an etching resist pattern. And the cooling circuit 3 was formed as shown in FIG. As a result of this half etching, the flow path 2 was included in the cooling circuit 3.

Step c: In this laminating step, as shown in FIG. 9 (d), the surface on which the cooling circuit 3 of the refrigerant flow path built-in plate (I) 10 on which the cooling circuit 3 is formed is formed on the insulating layer constituting material 4. Laminated so as to abut against (uses 3 pieces of FR-4 prepreg with a thickness of 210 μm), and hot-pressed at about 180 ° C. for about 60 minutes, as shown in FIG. It was set as the laminated body 5 in the point which manufactures a board. Further, in this embodiment, the surface of the refrigerant flow path built-in plate on which the cooling circuit 3 before hot pressing is formed is preliminarily blackened by a conventional method to improve the adhesion with the insulating layer. It was.

Step d: In this second etching resist pattern forming step, an etching resist layer is provided using a dry film on the surface of the refrigerant flow path built-in layer 10A in the outermost layer of the laminate 5, and an etching pattern is formed on the etching resist layer. 15 was exposed and developed to form a state shown in FIG.

Step e: Then, in the conductor circuit forming step, as shown in FIG. 10G, the surface of the refrigerant flow path built-in plate (I) 10 is etched using a copper chloride etchant to form an etching resist pattern. 15 was peeled off to form a conductor circuit 7, and a printed wiring board 1 with a cooling layer in which the conductor circuit 7 protruded from the substrate surface was obtained.

  In this example, a printed wiring board with a cooling layer was manufactured using the above-described second manufacturing method, using the refrigerant flow path built-in plate (II) having the above-described different metal layer. Hereinafter, description will be made mainly with reference to FIGS.

Step a: In this first etching resist pattern forming step, an etching resist layer is provided on the surface of the refrigerant flow path built-in plate shown in FIGS. 14A and 17A, and the etching resist layer is formed on the etching resist layer. As shown in FIGS. 17B and 17B, the etching resist pattern 15 is exposed and developed. However, in this second manufacturing method, since the conductor circuit shape is formed first, the etching resist pattern 15 formed here is for forming a conductor circuit. Note that the concept relating to the etching resist and the like is the same as described above, and thus the description thereof is omitted here.

  The refrigerant flow path built-in plate (II) 10 used here was manufactured as follows. A copper plate having a thickness of 150 μm as a first metal plate, a composite plate having a nickel layer having a thickness of 10 μm as a dissimilar metal layer in the middle of a copper layer having a thickness of 200 μm as a second metal plate, and a copper plate having a thickness of 100 μm as a third metal plate Using. And the 3rd metal plate provided the etching resist layer on both surfaces. Then, the etching pattern for forming the through-groove 18 in the said etching resist layer of both surfaces was exposed and developed. Then, etching was performed from one side using a copper chloride etchant to form a shape in which a cooling medium with a width of 150 μm can circulate and circulate to form a third metal plate.

Next, the surface used for joining the first metal plate, the second metal plate, and the third metal plate is subjected to glow discharge by applying an alternating current of 25 MHz in an extremely low pressure argon gas atmosphere of 3 × 10 ⁻³ Pa. Then, the activation treatment of both joint surfaces was performed. Then, the first metal plate 12 / third metal plate 14 / second metal plate 11 whose bonding surfaces are activated are stacked and rolled as shown in FIG. 2 (a), and shown in FIG. 2 (b). I stuck together. The rolling rate at this time was 1% under low pressure and room temperature. As a result, the refrigerant flow path built-in plate (I) 10 had a total thickness of 450 μm and an opening area of a built-in flow path 100 μm × 150 μm. And the antirust process layer was provided in the inner wall surface of this flow path like Example 1. FIG.

Step b: In this conductor circuit forming step, the refrigerant flow path built-in plate (II) 10 is half-etched with an alkali copper etching solution to peel off the etching resist pattern 15, and as shown in FIG. The conductor circuit 7 is formed by etching up to the metal layer (nickel layer) 13. At this time, since the dissimilar metal layer 13 is present, no further etching is performed, so that excessive etching has not occurred.

Step c: In this laminating step, the surface of the refrigerant flow path built-in plate (II) 10 on which the conductor circuit 7 is formed is formed on the insulating layer constituting material 4 (210 μm thick FR-4 prepreg as shown in FIG. 18D). 18), the laminate 5 shown in FIG. 18E was obtained by hot pressing at about 180 ° C. × 60. In addition, the surface of the refrigerant flow path built-in plate (II) 10 on which the conductor circuit 7 is formed before the hot press processing is blackened by a conventional method to improve the adhesion with the insulating layer. It was.

Step d: In this second etching resist pattern forming step, an etching resist layer is provided on the surface of the refrigerant flow path built-in plate (II) 10 of the laminate 5 using a dry film, and an etching pattern is formed on the etching resist layer. It exposed and developed and it was set as the state shown in FIG.18 (f).

Step e: In the cooling circuit forming step, as shown in FIGS. 16 (g) and 19 (g), the surface of the refrigerant flow path built-in plate (I) 10 is etched with an alkaline copper etching solution. Then, the etching resist pattern 15 was peeled off, and the cooling circuit 3 was formed.

  Further, since the refrigerant flow path built-in plate (II) used in this example includes a different metal layer, a different metal removal step for removing the different metal layer exposed between the circuits was additionally provided. In this dissimilar metal process, as shown in FIG. 19 (h), the cooling circuit 3 prints with the cooling layer protruding from the substrate surface by selective etching using a selective etching solution that dissolves nickel and does not dissolve copper. A wiring board 1 was obtained. In such a case, the printed wiring board with a cooling layer is in a state in which the cooling circuit protrudes from the surface, and this shape itself functions as a heat radiating fin and is excellent in heat dissipation.

  In this example, in the third manufacturing method described above, the printed wiring board with a cooling layer was manufactured using the above-described refrigerant flow path built-in plate (I). Hereinafter, description will be made mainly with reference to FIGS.

Step a: In this laminating step, as shown in FIG. 20 (a), the refrigerant flow path built-in plate (I) 10, the insulating layer constituting material 4 and the conductor layer 8 are overlapped to obtain a temperature of about 180 ° C. × 60 minutes. By hot pressing, the laminate 5 shown in FIG. 20B was obtained. As the refrigerant flow path built-in plate (I) 10 at this time, the same one as used in Example 1 was used. That is, the refrigerant flow path built-in plate (I) 10 has a total thickness of 600 μm, has a built-in flow path of 150 μm × 50 μm to 250 μm, and has an electroless nickel on the inner wall surface of the predetermined flow path. It has a rust-proofing layer by plating. Further, the surface of the refrigerant flow path built-in plate (I) 10 bonded to the insulating layer constituting material was subjected to blackening treatment by a conventional method to improve the adhesion with the insulating layer. As the insulating layer constituent material, one FR-4 prepreg having a thickness of 210 μm was used, and a copper foil having a thickness of 70 μm was used for the conductor layer 8.

Step b: In this etching resist pattern forming step, an etching resist layer is provided on the surface of the conductor layer 8 using a dry film, the etching resist layer is exposed and developed, and the state shown in FIG. Thus, an etching resist pattern 15 was formed. It is to be noted that an etching resist layer is also provided on the surface of the refrigerant flow path built-in plate, and the entire surface of the etching resist layer is left to prevent the refrigerant flow path built-in layer from being damaged by the etching solution.

Step c: In this circuit formation step, only the conductor layer 8 is etched using a copper chloride etchant, and the etching resist pattern is peeled off, whereby a predetermined conductor circuit 8 is formed as shown in FIG. It formed and the printed wiring board 1 with a cooling layer was obtained.

  Further, the present inventors use the refrigerant flow path built-in plate (II) used in Example 2 in place of the refrigerant flow path built-in plate (I) used in this embodiment, as shown in FIG. Printed wiring board with cooling layer 1 shown in FIG. 22 and a printed wiring board with cooling layer having the shape of protrusions functioning as heat radiation fins 16 (height 80 μm × width 50 μm) shown in FIG. As shown in FIG. 22 (c), the projections functioning as the dissimilar metal layer 13 (10 μm thick nickel layer) and the radiating fins 16 (height 80 μm × width 50 μm) using the plate and the refrigerant flow path built-in plate (IV) Although the printed wiring board 1 with a cooling layer having a shape was manufactured, all were able to be manufactured as a good printed wiring board.

  In this example, a printed wiring board with a cooling layer was manufactured using the above-described refrigerant flow path built-in plate (I) in the above-described fourth manufacturing method. Hereinafter, description will be made mainly with reference to FIGS. 25 and 26. 25 and 26 show a case where the refrigerant flow path built-in plate (I) having a different metal layer is used.

  The refrigerant flow path built-in plate (I) 10 used here was manufactured as follows. A composite plate having a 100 μm thick nickel layer on one side of a 200 μm thick copper plate is used as the first metal plate. A copper plate having a thickness of 400 μm was used as the second metal plate. Then, an etching resist layer was provided on both sides of a 400 μm thick copper plate. Then, the etching pattern for forming the recessed part 19 in the said etching resist layer of one side was exposed and developed. The entire surface of the etching resist layer on the other side was cured to protect the entire surface from the etching solution. Then, using a copper chloride etchant, half etching was performed from one side to form a linear concave portion having a depth of 150 μm and a width of 50 μm to 250 μm to obtain a second metal plate.

Next, an alternating current of 13.56 MHz in a very low pressure argon gas atmosphere of 3 × 10 ⁻³ Pa with respect to the surface (nickel layer side) used for joining the first metal plate and the recess forming surface of the second metal plate Was applied to cause glow discharge to activate both joint surfaces. And the 1st metal plate 12 and the 2nd metal plate 11 which activated the joint surface were laminated-rolled as shown to Fig.1 (a), and it bonded together as shown in FIG.1 (b). The rolling rate at this time was 1% under low pressure and room temperature. As a result, the refrigerant flow path built-in plate (I) 10 has a total thickness of 600 μm (there is a nickel layer as a dissimilar metal layer having a thickness of 100 μm inside), and has a built-in flow path of 150 μ × 50 μm to 250 μm. It had an area. And the antirust process layer was provided in the inner wall surface of this flow path similarly to Example 1. FIG.

Step a: In this laminating step, as shown in FIG. 25 (a), the refrigerant flow path built-in plate (I) 10, the insulating component 4 and the conductor layer 8 are sequentially stacked and placed at 180 ° C. for 60 minutes. The laminated body 5 was bonded to each other by hot pressing to a degree as shown in FIG. Further, the surface of the refrigerant flow path built-in plate (I) 10 bonded to the insulating layer constituting material was subjected to blackening treatment by a conventional method to improve the adhesion with the insulating layer. The insulating layer constituting material was 210 μm thick FR-4 prepreg, and the conductor layer 8 was 200 μm thick copper foil.

Step b: In this etching resist pattern formation step, an etching resist layer is provided on each surface of the conductor layer 8 and the refrigerant flow path built-in layer 10A using a dry film, the etching pattern is exposed to the etching resist layer, developed, As shown in FIG. 26C, an etching resist pattern 15 was formed.

Step c: In this etching step, as shown in FIG. 26 (d), the conductor layer is etched using an alkaline copper etching solution to form a circuit shape, and at the same time, the refrigerant flow path built-in plate (I) 10 is etched. The heat radiation fin 16 was formed by processing, and the etching resist pattern was peeled off. Here, as can be seen, when trying to obtain the printed wiring board with cooling layer 1 shown in FIG. 26 (d), the thickness from the surface of the refrigerant flow path built-in plate (I) 10 to the dissimilar metal layer, the conductor layer The dissimilar metal layer that was not dissolved after the etching was exposed, and the printed wiring board 1 with a cooling layer was obtained.

  In this example, a multilayer printed wiring board 30 with a cooling layer was manufactured using the printed wiring board 1 with a cooling layer obtained in Example 3 as an inner layer core material. Hereinafter, description will be made mainly using FIGS.

Step a: In this lamination step, as shown in FIG. 27A, the insulating layer constituting material 4 and the conductor layer 8 are formed on both surfaces of the printed wiring board 1 with a cooling layer obtained in Example 3 used as the inner layer core material. Are arranged and laminated. And it bonded by the hot press process of about 180 degreeC x 60 minutes, and was set as the state of the laminated body 5 shown in FIG.27 (b). The insulating layer constituting material used here was one 150 μm thick FR-4 prepreg, and the conductor layer 8 was a 18 μm thick copper foil.

Step b: In this step, a via hole shape having a diameter of 80 μm is formed on the conductor layer 8 located on the outer layer of the surface of the conductor circuit 7 of the printed wiring board 1 with the cooling layer using a carbon dioxide gas laser, and the palladium catalyst treatment is performed. Then, a copper plating layer 17 having a thickness of about 10 μm was formed by electroless copper plating and electrolytic copper plating to obtain a state shown in FIG.

Step c: In this etching resist pattern forming step, an etching resist is formed using a dry film on the surface of the outer conductor layer 8 (strictly speaking, the copper plating layer 17 is present on the surface but is not mentioned in the description). A layer was provided, and the etching resist layer was exposed and developed, and the etching resist pattern 15 was formed as shown in FIG.

Step d: In this etching step, the conductor layer is etched using a copper chloride etchant to form the shape of the outer layer circuit 22, the etching resist pattern is peeled off, and the multilayer print with cooling layer shown in FIG. A wiring board 30 was obtained.

  In this example, the multilayer printed wiring board 30 with a cooling layer in which the refrigerant channel built-in layer is located in the outer layer was manufactured using the refrigerant channel built-in plate (I) 10 used in Example 4. Hereinafter, description will be made mainly using FIGS. 30 to 32.

Step a: In this lamination step, the insulating layer constituting material 4 and the conductor layer are formed on one side of the inner layer core material 20 (a double-sided printed wiring board having inner layer circuits 21 on both sides of an FR-4 grade insulating layer having a thickness of 100 μm). 8 is arranged. Then, on the other surface side of the inner layer core material, the insulating layer constituting material 4 and the refrigerant flow path built-in plate (I) 10 were stacked so as to be stacked as shown in FIG. And it bonded by the hot press process of about 180 degreeC x 60 minutes, and was set as the state of the laminated body 5 shown in FIG.30 (b). The insulating layer constituting material used here was one 150 μm-thick FR-4 prepreg, and the conductor layer 8 was a 200 μm-thick copper foil.

Step b: In this step, in order to ensure electrical continuity between the surface of the conductor layer 8 and the inner layer circuit 21, a via hole shape having a diameter of 80 μm is formed from the conductor layer 8 located on the outer layer using a carbon dioxide laser. A palladium catalyst treatment was performed, and a copper plating layer 17 having a thickness of about 10 μm was formed by electroless copper plating and electrolytic copper plating to obtain a state shown in FIG.

Step c: In this etching resist pattern forming step, the outer conductor layer 8 (strictly speaking, the copper plating layer 17 is present on the surface but is not mentioned in the description) and the refrigerant flow path built-in plate (I) 10 An etching resist layer is provided on the outer surface using a dry film, the etching resist layer is exposed and developed, and an etching resist pattern 15 is formed as shown in FIG. 31 (d).

Step d: In this etching step, the conductor layer 8 was etched using a copper chloride etchant to form the shape of the outer layer circuit 22, and the etching resist pattern was peeled off. On the other hand, from the outer surface of the refrigerant flow path built-in plate (I) 10 to the dissimilar metal layer at the same time as the conductor layer 8, the heat radiating fins 16 are processed into the multilayer printed wiring board 30 with a cooling layer shown in FIG. Obtained.

  Since the printed wiring board with a cooling layer according to the present invention directly cools the printed wiring board itself as compared with the conventional fan cooling method using a flat motor, the cooling efficiency is high and the life of the printed wiring board can be expected to be extended. Moreover, since the printed wiring board with a cooling layer according to the present invention is easy to provide a layer that can be cooled using a refrigerant in the layer of the printed wiring board using a conventional printed wiring board manufacturing process, It does not require new capital investment. And since the obtained printed wiring board with a cooling layer can directly cool itself with a refrigerant | coolant, it also becomes possible to achieve further size reduction of an electronic device etc. easily.

It is the schematic diagram which caught the manufacturing flow of the refrigerant | coolant flow path built-in board | substrate A as a cross section. It is a cross-sectional schematic diagram which illustrated the variation of refrigerant | coolant flow path built-in board (I). It is the schematic which caught the manufacturing flow of the refrigerant | coolant flow path built-in board | substrate B as a cross section. It is a cross-sectional schematic diagram which illustrated the variation of refrigerant | coolant flow path built-in board (II). It is the schematic which caught the manufacturing flow of the refrigerant | coolant flow path built-in board | substrate C as a cross section. It is the schematic diagram which caught the manufacturing flow of the board | substrate D with a built-in refrigerant flow path as a cross section. It is a cross-sectional schematic diagram which illustrated the variation of refrigerant | coolant flow path built-in board (IV). It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacture flow of the printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacturing flow of the multilayer printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacturing flow of the multilayer printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacturing flow of the multilayer printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacturing flow of the multilayer printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacturing flow of the multilayer printed wiring board with a cooling flow path which concerns on this invention. It is the cross-sectional schematic diagram which showed the manufacturing flow of the multilayer printed wiring board with a cooling flow path which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed wiring board with a cooling layer 2 Flow path 3 Cooling circuit 4 Insulating layer constituent material 5 Laminated body 6 Insulating layer 7 Conductor circuit 8 Conductor layer 10 Refrigerant flow path built-in plate 11 1st metal plate 12 2nd metal plate 13 Heterogeneous metal Layer 14 Third metal plate 15 Etching resist pattern 16 Radiation fin 17 Copper plating layer 18 Through groove 19 Recess 20 Inner layer core material 21 Inner layer circuit 22 Outer layer circuit 30 Multilayer printed wiring board with cooling layer

Claims (12)

A method for manufacturing a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow,
A method for producing a printed wiring board with a cooling layer, which is obtained through the following steps a to e.
Step a: A first etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate, an etching pattern is exposed on the etching resist layer, and developed.
Step b: A cooling circuit forming step of half-etching the refrigerant flow path built-in plate to remove the etching resist pattern and form a cooling circuit.
Step c: A laminating step in which the surface of the refrigerant flow path built-in plate on which the cooling circuit is formed is laminated so as to come into contact with the insulating layer constituent material to form a laminated laminate.
Step d: A second etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate of the laminate, the etching pattern is exposed to the etching resist layer, and developed.
Step e: Conductor circuit forming step of etching the surface of the refrigerant flow path built-in plate, peeling off the etching resist pattern to form a conductor circuit, and forming a printed wiring board with a cooling layer. A method for manufacturing a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow,
A method for producing a printed wiring board with a cooling layer, which is obtained through the following steps a to e.
Step a: A first etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate, an etching pattern is exposed on the etching resist layer, and developed.
Step b: Conductor circuit forming step of half-etching the refrigerant flow path built-in plate, peeling off the etching resist pattern, and forming a conductor circuit.
Step c: A laminating step in which the surface of the refrigerant flow path built-in plate on which the conductor circuit is formed is laminated so as to abut against the insulating layer constituting material to form a laminated laminate.
Step d: A second etching resist pattern forming step in which an etching resist layer is provided on the surface of the refrigerant flow path built-in plate of the laminate, the etching pattern is exposed to the etching resist layer, and developed.
Step e: A cooling circuit forming step in which the surface of the refrigerant flow path built-in plate is etched, the etching resist pattern is removed to form a cooling circuit, and a printed wiring board with a cooling layer is formed. A method for manufacturing a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow,
A method for producing a printed wiring board with a cooling layer, which is obtained through the following steps a to c.
Step a: A laminating step in which a refrigerant flow path built-in plate, an insulating component, and a conductor layer are sequentially laminated and bonded together.
Step b: An etching resist pattern forming step in which an etching resist layer is provided on the surface of the conductor layer, the etching pattern is exposed to the etching resist layer, and developed.
Step c: A circuit forming step in which the conductor layer is etched to remove the etching resist pattern. A method for manufacturing a printed wiring board with a cooling layer including a refrigerant flow path built-in layer having a flow path through which a refrigerant can flow,
A method for producing a printed wiring board with a cooling layer, which is obtained through the following steps a to c.
Step a: A laminating step in which the refrigerant flow path built-in plate, the insulating layer constituent material, and the conductor layer are sequentially laminated and bonded together.
Step b: An etching resist pattern forming step in which an etching resist layer is provided on each surface of the conductor layer and the refrigerant flow path built-in plate, the etching pattern is exposed to the etching resist layer, and developed.
Step c: A circuit formation step in which the conductor layer is etched to form a circuit shape, and at the same time, the coolant channel built-in plate is etched to form a cooling circuit, and the etching resist pattern is peeled off. The refrigerant flow path built-in plate is obtained by using a first metal plate having a recess forming surface on one side and a second metal plate having smooth both surfaces, and attaching the second metal plate to the recess forming surface of the first metal plate. The manufacturing method of the printed wiring board with a cooling layer in any one of Claims 1-4. The refrigerant flow path built-in plate is obtained by sandwiching and bonding a third metal plate having a plurality of slit holes between a first metal plate and a second metal plate, both surfaces of which are smooth. The manufacturing method of the printed wiring board with a cooling layer in any one of Claim 4. The method for manufacturing a printed wiring board with a cooling layer according to claim 5 or 6, wherein the refrigerant flow path built-in plate is formed by half-etching one surface thereof to form a heat radiation fin shape. The printed wiring with a cooling layer according to any one of claims 1 to 7, wherein the refrigerant flow path built-in plate includes a dissimilar metal layer made of nickel, tin, aluminum, titanium, and an alloy thereof in the layer. A manufacturing method of a board. The manufacturing method of the printed wiring board with a cooling layer in any one of Claims 1-8 with which the flow path which the refrigerant | coolant flow path built-in board incorporates equips the inner wall surface with a rust prevention process layer. The printed wiring board with a cooling layer obtained by the manufacturing method in any one of Claims 1-9. The multilayer printed wiring board with a cooling layer which contains an inner-layer core material in the insulating layer of the printed wiring board with a cooling layer obtained by the manufacturing method of Claims 1-9. The multilayer printed wiring board with a cooling layer which formed the circuit in the outer layer using the printed wiring board with a cooling layer in any one of Claims 1-9 as an inner-layer core material.

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