JP2019029622A - Heat dissipation substrate and method for manufacturing heat dissipation substrate - Google Patents

Abstract

To provide a heat dissipation substrate with a short wire length, a high component mounting density, and high heat dissipation efficiency of a mounting component, and a method for manufacturing the same.SOLUTION: A method for manufacturing a heat dissipation substrate 1 with a prescribed thickness W1 in which an electronic component 2 is mounted in a face-up manner, comprises: a metal film forming step of forming a first metal film 2 on a support plate 20; a mask layer forming step of forming a mask layer 21 provided with an opening 21a in the first metal film 3; a bump forming step of forming a bump 6 by subjecting the opening 21a to plating; a laminating step of laminating the insulation layer 5 in which the bump 6 is embedded and a second metal film 4 after removing the mask layer 21; a support plate removing step of removing the support plate 20; and a bump exposing step of exposing an apex of the bump 6 by partly removing the second metal film 4 and the insulation layer 5. The bump forming step adjusts the bump 6 to a thickness W6 obtained by subtracting a thickness W2 of the electronic component 2 and a thickness W3 of the first metal film 3 from the prescribed thickness W1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat dissipation substrate and a method for manufacturing the heat dissipation substrate.

  An electronic component such as a semiconductor chip is often electrically connected to a wiring pattern of a printed wiring board on which the electronic component is mounted via a bonding wire. The bonding wire can be easily connected to a wiring pattern at a relatively low cost even for an electronic component in which a plurality of minute terminals are formed at a high density as the degree of integration increases and the number of functions of elements increases. For example, Patent Document 1 discloses a light emitting diode module in which a terminal of a semiconductor element and an electrode pattern on a circuit board are connected by a bonding wire. Here, in the prior art of Patent Document 1, the semiconductor element is disposed on the upper surface of the circuit board or the bottom of the through hole formed in the circuit board. For this reason, the bonding wire of patent document 1 is formed in the length according to the height difference of the arrangement | positioning of the terminal of a semiconductor element, and the electrode pattern on a circuit board.

  By the way, when the electronic component mounted on the printed wiring board is, for example, a high-frequency device, the influence of the wiring resistance or reactance component increases according to the length of the bonding wire, and the electrical performance deteriorates. In addition, since high-frequency devices often generate heat during operation, a printed wiring board is generally provided with a heat dissipation mechanism. For this reason, for example, in the semiconductor module disclosed in Patent Document 2, a semiconductor element is flip-mounted inside a cavity formed in a printed wiring board and is formed to penetrate from the mounting surface to the back surface of the substrate. The semiconductor element is dissipated by thermal vias. More specifically, the semiconductor module of Patent Document 2 eliminates the need for a bonding wire by mounting a semiconductor element via a bump on one electrode provided on the surface of the substrate, and from the electrode via a thermal via to the substrate. Heat is released from the other electrode provided on the back surface of the substrate.

JP 2008-288229 A JP 2003-92372 A

  However, when the semiconductor element is flip-mounted as in the prior art of Patent Document 2, the heat generated by the semiconductor element is transmitted to the surface electrode of the substrate through a minute bump corresponding to the dimension of the terminal. The heat dissipation performance may be insufficient due to the restriction of the heat dissipation path. Further, in the semiconductor module of Patent Document 2, in order to transmit the heat generated by the semiconductor element to the other electrode provided on the back surface of the substrate through the thermal via, there are provided a plurality of thermal vias whose individual cross-sectional areas are limited. Even so, the heat dissipation efficiency may be insufficient.

  Here, as a means for efficiently transferring the heat generated by the semiconductor element to the back surface of the substrate and releasing it, for example, a through hole is formed at the position of the substrate on which the semiconductor element is mounted, and a metal member having high thermal conductivity is press-fitted In addition, a method using a so-called inlay substrate in which a semiconductor element is arranged on a press-fitted metal can be considered. However, while the inlay substrate can dissipate heat from the entire bottom surface of the mounted semiconductor element, when the semiconductor element is flip-mounted, multiple terminals are short-circuited by a metal member, so the face-up that directs the terminals to the outside of the substrate Thus, a semiconductor element is arranged. Moreover, since the metal member press-fitted into the through-hole of the inlay substrate is generally formed by performing a punching process on a metal plate, it is extremely difficult to form the metal member with a diameter of approximately 2 mm or less. In addition, it is extremely difficult to form a metal member along the shape of the semiconductor element. For this reason, for example, an inlay substrate has an excessively large heat dissipation mechanism for a semiconductor element that is miniaturized to at least one sub-millimeter order, and not only reduces the wiring area and component mounting density of the substrate. There is a possibility that the wiring connecting the semiconductor element and the electrode becomes long. Furthermore, in the inlay substrate, the end portion of the press-fitted metal member becomes an R surface by press punching, and the corners of the through holes provided in the substrate cannot be completely filled with the metal member by press-fitting. There is a possibility that the efficiency of heat conduction to the electrode provided on the back surface is lowered.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a heat dissipating board having a short wiring length of a mounting component and high component mounting density and heat dissipating efficiency, and a manufacturing method thereof. is there.

<First Aspect of the Present Invention>
A first aspect of the present invention is a method of manufacturing a heat dissipation substrate having a predetermined thickness on which an electronic component is mounted face-up, a metal film forming step of forming a first metal film on a support plate, and an opening Forming a mask layer on the first metal film, forming a bump by plating the opening, forming a bump, and embedding the bump after removing the mask layer Laminating step of laminating an insulating layer to be formed and a second metal film covering the surface of the insulating layer, a supporting plate removing step of removing the supporting plate, and partially removing the second metal film and the insulating layer A bump exposing step of exposing the top of the bump by adjusting the bump to a thickness obtained by subtracting the thickness of the electronic component and the first metal film from the predetermined thickness in the bump forming step. It is a method of manufacture.

  According to the manufacturing method of the heat dissipation substrate, the first metal film and the second metal film are formed on both surfaces of the heat dissipation substrate, and the bump is formed integrally with the first metal film by plating, and the bump is formed on the top of the bump. A cavity in which the electronic component can be mounted face-up is formed on the second metal film side. As a result, when the electronic component is mounted in the cavity, the heat dissipation substrate can efficiently transmit the heat generated by the electronic component to the first metal film via the bumps contacting the bottom of the electronic component to dissipate the heat. . At this time, the thickness of the bump is adjusted to a thickness obtained by subtracting the thickness of the electronic component and the first metal film from the predetermined thickness of the heat dissipation substrate. For this reason, the heat dissipation substrate can shorten the wiring length of the wire connecting the electronic component and the second metal film by making the surface of the electronic component and the surface of the second metal film flush with each other. Even when an electronic component that is susceptible to the influence of wiring resistance or reactance component is mounted according to the wiring length, it is possible to reduce the possibility that the electrical performance related to signal input / output will deteriorate.

  In addition, the heat dissipation substrate can contact the entire bottom surface of the electronic component to be mounted on the bump, and unlike a general inlay substrate in which the heat dissipation metal member is formed by stamping, the bump uses a mask layer. Therefore, even when the electronic component is downsized to the sub-millimeter order, the bump can be formed small according to the size of the electronic component. That is, the area in which the conductor pattern can be formed on the second metal film is increased, and other components can be arranged on the second metal film at high density. Thereby, the heat dissipation board according to the present invention can set the wiring length of the mounted component to be short, and can improve the wiring area of the substrate and the component mounting density.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, a patterning step of forming a conductor pattern on the first metal film and the second metal film is provided. It is a manufacturing method of a radiating board which forms a part of the connected 1st metal film as a radiating pad independent of the conductor pattern.

  In the patterning process of forming a conductor pattern by patterning the first metal film and the second metal film respectively formed on both surfaces of the heat dissipation substrate, a part of the first metal film is formed as a heat dissipation pad independent of the conductor pattern. By doing so, the heat dissipating pad and the other conductor pattern can be formed in the same step, and the number of manufacturing steps and the manufacturing cost associated therewith can be reduced.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, in the first or second aspect of the present invention described above, in the mask layer forming step, the opening formed in the mask layer has a planar shape substantially the same as the electronic component. It is a manufacturing method of the heat dissipation board formed in the same way.

  In the mask layer forming step, the opening formed in the mask layer has substantially the same planar shape as the electronic component, so that the planar shape of the formed bump is also substantially the same as the electronic component. Thereby, the heat dissipation substrate can minimize the range of the second metal film and the insulating layer partially removed at the top of the bump while maintaining the heat dissipation efficiency from the electronic component to the bump. The effect similar to the 1st aspect of can be show | played more effectively.

<Fourth aspect of the present invention>
According to a fourth aspect of the present invention, there is provided a heat dissipation substrate having a predetermined thickness on which an electronic component is mounted face-up, a first metal film, a bump formed on the first metal film by plating, An insulating layer that embeds the bump, a second metal film that covers the surface of the insulating layer, and a component housing that exposes the top of the bump by partially removing the second metal film and the insulating layer; The bump is a heat dissipation board having a thickness obtained by subtracting the thickness of the electronic component and the first metal film from the predetermined thickness.

  The heat dissipation substrate has a first metal film and a second metal film formed on both sides, and bumps formed by plating are integrated with the first metal film, and electronic components are mounted face-up on top of the bumps. The component accommodating part which can do is formed in the 2nd metal film side. Thus, when the electronic component is mounted on the component housing portion, the heat dissipation substrate can efficiently dissipate the heat generated by the electronic component through the bumps contacting the bottom of the electronic component to the first metal film. it can. At this time, the bump has a thickness obtained by subtracting the thickness of the electronic component and the first metal film from the predetermined thickness of the heat dissipation substrate. For this reason, the heat dissipation substrate can shorten the wiring length of the wire connecting the electronic component and the second metal film by making the surface of the electronic component and the surface of the second metal film flush with each other. Even when an electronic component that is susceptible to the influence of wiring resistance or reactance component is mounted according to the wiring length, it is possible to reduce the possibility that the electrical performance related to signal input / output will deteriorate.

  In addition, the heat dissipation board can contact the entire bottom surface of the electronic component to be mounted on the bump, and, unlike a general inlay substrate in which the heat dissipation metal member is formed by press punching, the bump is formed by plating. Therefore, even when the electronic component is downsized to a sub-millimeter order size, bumps having dimensions corresponding to the mounted electronic component are provided. Thereby, the heat dissipation board according to the present invention can set the wiring length of the mounted component to be short, and can improve the wiring area of the substrate and the component mounting density.

  ADVANTAGE OF THE INVENTION According to this invention, the wiring length of mounting components is short, and the heat dissipation board with high component mounting density and heat dissipation efficiency, and its manufacturing method can be provided.

It is sectional drawing of the thermal radiation board which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the manufacturing process of a heat sink. It is sectional drawing which shows the structure at the time of forming a thermal radiation board | substrate as an inlay board | substrate. It is sectional drawing which shows the structure at the time of forming a thermal radiation board | substrate as an inlay board | substrate. It is sectional drawing of the thermal radiation board | substrate which concerns on 2nd Embodiment of this invention. It is sectional drawing of the thermal radiation board | substrate which concerns on 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings based on the first to third embodiments. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. The drawings used for describing each embodiment schematically show the heat dissipation substrate and its constituent members according to each embodiment, and are partially emphasized, enlarged, reduced, or omitted for better understanding. Etc., and may not accurately represent the scale, shape, etc. of the heat dissipation substrate and its constituent members. Furthermore, all the various numerical values used in each embodiment show an example, and can be changed variously as necessary.

<First Embodiment>
FIG. 1 is a cross-sectional view of a heat dissipation board 1 according to the first embodiment of the present invention. The heat dissipation board 1 is a printed wiring board having a predetermined thickness W1, and efficiently releases heat generated by the electronic component 2 mounted face up to the outside of the board, as will be described in detail later. Here, the electronic component 2 is a high-frequency device having a thickness W2, and is a semiconductor chip having a relatively small planar dimension such as 0.6 mm × 0.3 mm. The electronic component 2 includes a plurality of terminals 2a. In the present embodiment, the electronic component 2 is formed so that the plurality of terminals 2a do not protrude from the component surface.

  The heat dissipation substrate 1 includes a first metal film 3, a second metal film 4, an insulating layer 5, and bumps 6. The heat dissipation board 1 accommodates the electronic component 2 as a so-called cavity structure, and performs signal input / output with the electronic component 2 via the wire 8. The electronic component 2 and the wire 8 may be covered with the sealing resin 7 as an overcoat.

  The first metal film 3 and the second metal film 4 are copper foils respectively formed on both surfaces of the heat dissipation substrate 1 and are patterned to form a wiring layer. In the heat dissipation substrate 1 in the present embodiment, the second metal film 4 is formed on the side where the electronic component 2 is mounted with respect to the thickness direction of the heat dissipation substrate 1. The first metal film 3 has a thickness W3, and a part thereof is formed as a heat radiation pad 3a for radiating heat from the electronic component 2 as will be described in detail later.

  The insulating layer 5 is made of, for example, an insulating resin, and is a base material of the heat dissipation substrate 1 including the first metal film 3 and the second metal film 4 as wiring layers on both surfaces. In this embodiment, the insulating layer 5 includes a core substrate 50 having rigidity and a prepreg 51 having fluidity in the manufacturing process, as will be described later.

  The bumps 6 are made of a metal having good thermal conductivity, such as copper, and are formed integrally with the heat dissipation pad 3a, and the electronic component 2 is disposed on the top, so that the heat generated by the electronic component 2 is dissipated. Communicate efficiently to 3a.

  Next, a method for manufacturing the heat dissipation substrate 1 will be described in detail with reference to FIGS. Here, FIGS. 2 to 10 show cross sections in each manufacturing process of the heat dissipation substrate 1.

  First, as shown in FIG. 2, the support plate 20 is prepared, and the first metal film 3 is formed on the support plate 20 (metal film forming step). The support plate 20 is formed of, for example, a stainless steel plate (SUS plate). The first metal film 3 is a copper foil formed by, for example, plating the support plate 20, and becomes a conductor pattern constituting one wiring layer of the heat dissipation substrate 1 by performing a patterning process in a subsequent process. .

  Next, as shown in FIG. 3, a mask layer 21 is formed on the first metal film 3 (mask layer forming step). The mask layer 21 is made of a general resist resin material such as a dry film, and has an opening 21a at a position where the electronic component 2 is to be mounted in a plan view. The opening 21a is formed, for example, by removing a part of the mask layer 21 by exposure / development, and in this embodiment, the planar shape is substantially the same as that of the electronic component 2. As a result, the first metal film 3 is exposed in the opening 21 a formed in the mask layer 21.

  Subsequently, as shown in FIG. 4, the opening 21 a formed in the mask layer 21 is plated with, for example, copper to form the bump 6 (bump forming step). At this time, the thickness W6 of the bump 6 is adjusted to a thickness obtained by subtracting the thickness W2 of the electronic component 2 and the thickness W3 of the first metal film 3 from the predetermined thickness W1 of the heat dissipation substrate 1. That is, the bump 6 is formed to have a thickness W6 calculated by W6 = W1-W2-W3. In general, the thickness of the printed circuit board or the wiring layer is determined by the industry standard according to the type of the substrate and the material. Therefore, the predetermined thickness W1 of the heat dissipation substrate 1 and the thickness W3 of the first metal film 3 are selected from the predetermined thicknesses defined in the industry standard.

  Next, as shown in FIG. 5, the mask layer 21 provided on the first metal film 3 is removed. Thereby, the bump structure 10 in which the first metal film 3 and the bump 6 are integrated is formed. At this time, the bump 6 can be formed to have a planar dimension as small as, for example, a circle having a diameter of about 0.05 mm and a square having a side of about 0.05 mm.

  Subsequently, as shown in FIG. 6, the second metal film 4 is disposed on the bump structure 10 through the core base material 50 and the prepreg 51 having insulating properties. At this time, the core substrate 50 and the prepreg 51 are laminated on the first metal film 3 so that an opening larger than the planar shape of the bump 6 is formed and the opening passes through the bump 6. Moreover, in this embodiment, the core base material 50 is arrange | positioned so that the two prepregs 51 may be pinched | interposed. Here, the second metal film 4 is made of, for example, a general copper foil, and becomes a conductor pattern constituting a wiring layer on one side of the heat dissipation substrate 1 by performing a patterning process in a later step. Then, the core structure 50, the prepreg 51, and the second metal film 4 are pressure-bonded to the bump structure 10 under a high temperature condition, so that the laminated structure 11 is formed on the support plate 20 as shown in FIG. It is formed (lamination process).

  In the laminated structure 11, the prepreg 51 fluidized in the laminating process flows into the gaps around the core base material 50 and the bump structure 10, whereby the bumps 6 are formed by the insulating layer 5 composed of the core base material 50 and the prepreg 51. Buried. The laminated structure 11 is a double-sided plate in which the first metal film 3 covers one surface of the insulating layer 5 including the core substrate 50 and the second metal film 4 covers the other surface. In the laminated structure 11, the support plate 20 is removed when the form is stabilized as a double-sided plate (support plate removing step).

  Next, as shown in FIG. 8, in the second metal film 4 of the laminated structure 11, a region corresponding to the portion where the bumps 6 are disposed is removed by etching, so that the insulating layer 5 is partially exposed. Furthermore, as shown in FIG. 9, the partially exposed insulating layer 5 is removed by cutting or laser processing. As a result, the multilayer structure 11 is formed with a component accommodating portion 12 for accommodating the electronic component 2 in the removed second metal film 4 and insulating layer 5 region, and the top of the bump 6 is exposed. (Bump exposure process). That is, the laminated structure 11 can accommodate and mount the electronic component 2 in the component housing portion 12 as a so-called cavity structure, and the bottom surface of the electronic component 2 mounted in the component housing portion 12 is exposed. It will be in contact with the top of the bump 6. Here, the surface of the exposed top portion of the bump 6 is cleaned by a desmear process and a soft etching process as necessary.

  Subsequently, as shown in FIG. 10, the first metal film 3 and the second metal film 4 are patterned to form conductor patterns as wiring layers on both surfaces of the laminated structure 11 (patterning step). Thereby, the heat dissipation board 1 before the electronic component 2 is mounted is completed. At this time, a portion of the first metal film 3 connected to the bump 6 is formed as a heat dissipation pad 3a independent of other conductor patterns. The heat dissipating pad 3a transmits heat generated by the operation of the electronic component 2 via the bumps 6 and efficiently releases the transmitted heat to the outside of the heat dissipating substrate 1 according to the surface area. The second metal film 4 is formed with an electrode (not shown) in the vicinity of the component housing portion 12 by patterning.

  As shown in FIG. 1, the heat dissipation substrate 1 formed by each of the manufacturing processes described above includes the electronic component 2 housed face-up in the component housing portion 12, and the electrodes and electrons formed on the second metal film 4. The electronic component 2 can be mounted by connecting the terminal 2a of the component 2 via the wire 8. Although not essential to the present invention, the space between the component housing portion 12 and the electronic component 2 and the upper surface of the electronic component 2 may be covered with the sealing resin 7 including the wires 8. Moreover, although the bottom face of the electronic component 2 is in direct contact with the top of the bump 6 in the present embodiment, it may be connected to the top of the bump 6 through an adhesive having high thermal conductivity.

  As described above, according to the heat dissipation board 1 of the present invention, the bumps 6 that transmit the heat generated from the mounted electronic component 2 to the first metal film 3 formed as the heat dissipation pads 3a are formed, and the bumps 6 is adjusted to a thickness obtained by subtracting the thickness W2 of the electronic component 2 and the thickness W3 of the first metal film 3 from the predetermined thickness W1 of the heat dissipation substrate 1. As a result, when the electronic component 2 is mounted on the heat dissipation board 1, the heat dissipation board 1 has the surface of the terminal 2 a to which both ends of the wire 8 are connected and the surface of the second metal film 4 being flush with each other. The wiring length of 8 can be set short. Therefore, even if the heat dissipation substrate 1 is a high-frequency device in which the electronic component 2 is easily affected by wiring resistance or reactance component according to the length of the wire 8, for example, the electrical performance related to signal input / output deteriorates. The fear can be reduced.

  Further, the heat dissipation board 1 according to the present invention can bring the entire bottom surface of the electronic component 2 to be mounted into contact with the bumps 6, and the first metal film 3 formed as the heat dissipation pad 3 a and the bumps 6 are plated. Therefore, the heat radiation efficiency can be improved as compared with general thermal vias and inlays. Further, in the heat dissipation substrate 1, since the bumps 6 are formed by plating using the mask layer 21, even when the electronic component 2 is downsized to a sub-millimeter order size, the size of the electronic component 2 is reduced. Corresponding bumps 6 can be formed. Thereby, the heat dissipation board 1 according to the present invention can improve the wiring area and the component mounting density of the board as compared with the inlay board in which the heat dissipation metal member is formed by press punching.

  Here, the effect of the present invention will be described by exemplifying a general inlay substrate. FIG. 11 is a cross-sectional view showing the structure of the heat dissipation substrate 30 when the heat dissipation substrate 1 is to be formed as a general inlay substrate. The electronic component 2, the first metal film 3, the second metal film 4, and the insulating layer 5 included in the heat dissipation board 30 are the same as those of the heat dissipation board 1 described above. Detailed description is omitted.

  The heat dissipation substrate 30 as an inlay substrate is formed with through holes 31 penetrating both surfaces of the heat dissipation substrate 30, and inlays 32 as heat dissipation metal members are press-fitted into the through holes 31. The electronic component 2 is arranged on the inlay 32, and the terminal 2a of the electronic component 2 and the second metal film 4 are connected via the wire 8a.

  Here, since the inlay 32 press-fitted into the heat radiating substrate 30 is generally formed by press punching from a metal plate, it is extremely difficult to form the inlay 32 with a dimension of approximately 2 mm or less in diameter. Therefore, when the electronic component 2 is downsized to a sub-millimeter size as described above, the size of the inlay 32 with respect to the electronic component 2 becomes excessively large, and the wire 8a needs to be set long. In addition, since it is difficult to adjust the size of the inlay 32 with respect to the through hole 31, the surface of the terminal 2a of the electronic component 2 and the surface of the second metal film 4 may not be flush with each other. It is necessary to set the wire 8a longer according to the height difference.

  In addition, the heat dissipation substrate 30 as the inlay substrate has a corner portion of the inlay 32 that is slightly rounded by a stamping process from a metal plate, so that the corner of the through hole 31, that is, the inlay 32 and the first metal film 3. The first gap 32a is formed at the boundary, and there is a possibility that the heat transfer efficiency from the inlay 32 to the first metal film 3 is lowered.

  Furthermore, as shown in FIG. 12, when the plating layer 33 is formed on the surface of the inlay 32 and the first metal film 3 in order to solve the problem caused by the first gap 32a, the plating metal flows into the first gap 32a. As a result, a second gap 33 a is newly formed in the plating layer 33. For this reason, the heat dissipation substrate 30 as the inlay substrate has limited improvement in heat conduction efficiency with respect to an increase in the thickness of the first metal film 3.

  On the other hand, in the heat dissipation substrate 1 according to the present invention, bumps 6 are formed by plating, and the thickness W6 thereof is changed from the predetermined thickness W1 of the heat dissipation substrate 1 to the thickness W2 of the electronic component 2 and the first metal film 3. The thickness is adjusted by subtracting the thickness W3. As a result, according to the present invention, it is possible to provide a heat dissipation substrate 1 having a short wiring length of mounted components, a high component mounting density and high heat dissipation efficiency, and a method for manufacturing the same.

Second Embodiment
Next, a second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in the aspect of the electronic component 2 and the bump 6 of the first embodiment described above. Hereinafter, parts different from those of the first embodiment will be described, and components common to the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

  FIG. 13 is a cross-sectional view of the heat dissipation board 13 according to the second embodiment of the present invention. The heat dissipation board 13 is configured to accommodate the electronic component 2 ′ having a shape in which a plurality of terminals 2 a ′ protrude from the main body surface of the electronic component 2 ′ in the component accommodating portion 12. In other words, the heat dissipation substrate 13 has the thickness of the electronic component 2 ′ from the bottom of the electronic component 2 ′ to the top of the terminal 2a ′ so that the top of the terminal 2a ′ and the surface of the second metal film 4 are flush with each other. The thickness of the bump 60 is adjusted. Thereby, according to 2nd Embodiment of this invention, even when it is a case where the electronic component 2 'of the shape where terminal 2a' protruded from the surface is mounted, the thermal radiation board 1 which concerns on 1st Embodiment of this invention mentioned above The same operational effects can be achieved.

<Third Embodiment>
Subsequently, a third embodiment of the present invention will be described. The third embodiment is different from the first embodiment in the aspect of the bump 6 of the first embodiment described above. Hereinafter, parts different from those of the first embodiment will be described, and components common to the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

  FIG. 14 is a cross-sectional view of the heat dissipation board 14 according to the third embodiment of the present invention. The heat dissipation board 14 is configured such that the planar dimensions of the bumps 61 are larger than those of the electronic component 2 accommodated in the component accommodating portion 12. That is, the planar dimension of the bump 61 is adjusted to be larger than the planar dimension of the electronic component 2 within a range where the planar dimension of the component housing portion 12 is not widened. This is achieved by adjusting the planar dimension of the opening 21a formed in the mask layer 21 in the bump forming step in the first embodiment of the present invention. Thereby, according to 3rd Embodiment of this invention, in addition to having the same effect as the heat sink 1 which concerns on 1st Embodiment of the above-mentioned, this heat sink board which concerns on 1st Embodiment of this invention. The heat radiation efficiency of the electronic component 2 can be improved without increasing the wiring length of the wire 8 as the planar dimension of the bump 61 is increased as compared with 1.

  Although the description of the embodiment is finished as described above, the present invention is not limited to the above-described embodiment. For example, in the first embodiment, in the lamination process, the laminated structure 11 in which the top of the bump 6 is completely filled with the prepreg 51 as illustrated in FIG. 7 is illustrated, but the amount of the prepreg 51 is set so that the top of the bump 6 is exposed. By adjusting, the removal of the prepreg 51 in the bump exposing step may be omitted.

DESCRIPTION OF SYMBOLS 1, 13, 14 Radiation board 2, 2 'Electronic component 3 1st metal film 4 2nd metal film 5 Insulating layer 6, 60, 61 Bump 20 Support plate 21 Mask layer 21a Opening part

Claims (4)

A method of manufacturing a heat dissipation board having a predetermined thickness on which electronic components are mounted face-up,
A metal film forming step of forming a first metal film on the support plate;
A mask layer forming step of forming a mask layer provided with an opening in the first metal film;
A bump forming step of forming a bump by plating the opening;
After removing the mask layer, a laminating step of laminating an insulating layer in which the bump is embedded and a second metal film covering the surface of the insulating layer;
A support plate removing step of removing the support plate;
A bump exposing step of exposing the top of the bump by partially removing the second metal film and the insulating layer, and
In the bump forming step, the bump is adjusted to a thickness obtained by subtracting the thickness of the electronic component and the first metal film from the predetermined thickness. A patterning step of forming a conductor pattern on the first metal film and the second metal film;
The method of manufacturing a heat dissipation substrate according to claim 1, wherein in the patterning step, a part of the first metal film connected to the bump is formed as a heat dissipation pad independent of the conductor pattern.   3. The method for manufacturing a heat dissipation substrate according to claim 1, wherein, in the mask layer forming step, the opening formed in the mask layer is formed to have substantially the same planar shape as the electronic component. A heat dissipation board having a predetermined thickness on which electronic components are mounted face up,
A first metal film;
Bumps formed by plating on the first metal film;
An insulating layer for embedding the bump;
A second metal film covering the surface of the insulating layer;
A component housing that exposes the top of the bump by partially removing the second metal film and the insulating layer;
The bump has a thickness obtained by subtracting the thickness of the electronic component and the first metal film from the predetermined thickness.

Images