JP2005101417A - Method for manufacturing direct-current to direct-current power unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a DC-DC power unit which can easily be manufactured without increasing stages and is small-sized and highly reliable. <P>SOLUTION: The method for manufacturing the DC-DC power unit constituted by joining electromagnetic wave shielding plates 1 formed of conductors provided with insulating films with both surfaces of a circuit board mounted with electronic components including a semiconductor 8 for power conversion, a capacitor 9, and an inductor in one body across prepreg 4 through thermocompression bonding includes a stage of providing opening parts 21, 22, and 23 which are large enough for the prepreg 4 to flow when the electromagnetic wave shielding plates are joined in the circuit board 7 and a stage of forming a plurality of devices by cutting. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a DC-DC power supply device, and more particularly to a method for manufacturing a low-voltage integrated DC-DC power supply device in which electromagnetic wave shielding plates are formed on both front and back surfaces.

  Technologies such as miniaturization, thinning, and high performance of mobile devices using batteries as a driving source, particularly mobile phones, are rapidly progressing. These technologies such as miniaturization depend on technologies such as miniaturization of electronic components such as L, C, R, and semiconductor used in the technology. In addition, DC-DC power supply devices have been developed not only for surface-mounting structures that have been made smaller and thinner using DC-DC converters and regulators, but also for multi-layer boards that contain individual electronic components. ing.

  Under such circumstances, many manufacturing methods for mounting electronic components on a multilayer substrate using a prepreg have been disclosed. For example, Patent Document 1 discloses a method of manufacturing a multilayer substrate in which a hole is formed in a prepreg, a ceramic chip constituting a capacitor or an inductor is built in, and a plating film and a copper foil are patterned on the prepreg and the ceramic chip. Has been.

  In addition, for example, Patent Document 2 discloses a method for thinning a multilayer board, which encloses electronic components mounted on a plurality of electronic component mounting boards using a prepreg that secures a space in which the electronic components are accommodated, and applies heat. A manufacturing method for three-dimensionally laminating by pressure is disclosed.

  As a method for enhancing the electromagnetic wave shielding effect, conventionally, as shown in FIG. 5, in the DC-DC power supply device 114, an electronic component 140 such as a capacitor, an inductor, and a power conversion semiconductor is mounted in a metal case 113. A method of placing and molding the circuit board 117 having the terminals 111 is generally performed. However, in this case, although the electromagnetic wave shielding is complete, the size and weight are serious problems because the metal case is used. Therefore, recently, there are a manufacturing method in which an electromagnetic wave shielding layer composed of a composite layer using a metal layer or magnetic powder is provided in a multilayer board on which electronic components are mounted, and a method in which the entire board on which electronic components are mounted is covered with an electromagnetic wave shielding layer. Has been developed.

  For example, in Patent Document 3, in order to completely shield electromagnetic waves, the entire substrate on which electronic components are mounted is immersed and applied in a radio wave absorbing material or conductive paint, so that an electromagnetic wave shielding film is applied to the entire substrate. A method of manufacturing and connecting this electromagnetic wave shielding film to a common line of a circuit of a substrate is disclosed.

  In Patent Document 4, an insulating substrate having a space in which an electronic component is accommodated without contacting a wall surface is used, and a metal layer for shielding is formed in this space by, for example, a wet plating method. A method of shielding an electronic circuit device joined to a layer is disclosed.

JP 2002-164660 A JP 2001-119147 A JP 09-246775 A JP 2001-267710 A

  However, in the multilayer substrate manufacturing method using the conventional prepreg as described above, holes are formed in the prepreg, and electronic components are mounted in multiple stages, which is suitable for mounting relatively thick components. When a component having a small thickness is mounted, there is a problem in that the thickness of the substrate and the space area in which the component is not mounted increase, and the entire apparatus on which the component is mounted becomes thick. In addition, the method of opening the prepreg on the mounting part of the electronic component is also a very effective means when the electronic component is as thick as mm, but most of the prepreg is mounted when mounting the electronic component of μm order. Since it is embedded, it becomes an unnecessary process, and it is inevitable that man-hours are increased.

  Next, regarding the electromagnetic wave shielding method, the method of immersing and applying in a paint made of a radio wave absorbing material and a synthetic resin is very suitable as a method of shielding the entire apparatus, but the thickness for applying the entire apparatus. It is difficult to control, and the whole apparatus tends to be large by applying a thick coating on the safe side. Also, when forming an electromagnetic wave shielding layer by wet plating, a sufficient space is required to allow the plating solution to penetrate, so that bridge formation due to plating is further prevented between the product and the electromagnetic wave shielding layer. Therefore, there is a problem that the volume itself is greatly increased because it is necessary to secure an extra space.

  An object of the present invention is to solve the above-mentioned problems and to provide a method for manufacturing a small-sized and highly reliable DC-DC power supply device that can be easily manufactured without increasing the number of steps.

  In order to solve the above-described problems, the present invention is an integrated structure using a prepreg having a predetermined uniform thickness for a circuit board on which electronic components are mounted and an electromagnetic wave shielding plate. A large number of openings are provided in the portions other than the pattern of the substrate patterned with rolled copper foil and the side portions so that the resin contained in the prepreg of a predetermined thickness flows, and inductors and capacitors are mounted. And an insulating-coated conductor (electromagnetic wave shielding plate) are arranged and integrated by thermocompression bonding.

  That is, the present invention is a method of manufacturing a DC-DC power supply apparatus in which an electromagnetic wave shielding plate is joined by thermocompression bonding via a prepreg to both surfaces of a circuit board on which an electronic component including an inductor and a capacitor is mounted or incorporated. A method for manufacturing a DC-DC power supply apparatus comprising the step of providing the substrate with an opening having a size that allows the prepreg to flow when the electromagnetic wave shielding plate is joined.

  In addition, the present invention is the above-described method for manufacturing a DC-DC power supply device, which includes a step of forming a plurality of devices by cutting.

  According to the present invention, the opening formed on one side of the circuit board having a size capable of manufacturing the plurality of devices has a width greater than or equal to the cutting margin, the total length is equal to or less than the cutting length, and It is a manufacturing method of said DC-DC power supply device characterized by being at least 1 or more.

  Further, the present invention is the above-described method for manufacturing a DC-DC power supply device, wherein the prepreg is bonded in combination with a thickness of 200 μm or less.

  In the present invention, the electromagnetic wave shielding plate is a sheet or nonwoven fabric comprising a conductor layer made of a foil, wire, or woven metal, and an insulating layer made of a resin or metal oxide that is insulation-coated on the conductor layer. The above-described method for manufacturing a DC-DC power supply device is characterized in that the conductor layer has an average thickness of 170 μm or less and one side of the insulating layer has an average thickness of 50 μm or less.

  Further, the present invention provides the above-described DC-DC power supply device, wherein the electronic component is arranged by being stacked up and down via a prepreg having a thickness of 270 μm or less with a conductor having an electromagnetic wave shielding effect interposed therebetween. Is the method.

  As described above, the DC-DC power supply device using the electromagnetically shielded electromagnetic shielding plate according to the present invention has an effect of contributing to miniaturization and simplification of the manufacturing process by being integrated without being covered with the metal case. Further, by using the minimum necessary thin prepreg, the entire apparatus is thinned, and excellent reliability can be secured by eliminating mechanical stress and heat dissipation.

  Recently, advances in semiconductor technology have made it possible to manufacture DC-DC power supply devices and electronic components that satisfy the requirements for thinning that are mounted in the order of μm with extremely few accessory parts. In addition, since the conversion efficiency is high even during operation, the amount of heat generation is reduced, and further, the current loss during standby is small, enabling high-density mounting of these devices. By increasing the mounting density of electronic components, the space in the mounting area can be made extremely small, and by flowing the prepreg, the resin contained in the prepreg can be filled in most of the space in the mounting area. Can be greatly improved.

  However, in order to completely fill the mounting region with the flowing prepreg, a new method is required to serve as a weir that hinders the flow of the prepreg when one side is a flat substrate. Therefore, an opening is provided in a portion other than the wiring pattern of the substrate so that the prepreg can be actively wound without disturbing the fluidity of the prepreg. In addition, when a circuit is formed with a frame, an aerial wiring, or the like, the structure can be used so that the flow of the prepreg can be used to wrap around the mounting space. Furthermore, as the board on which the electronic component is mounted becomes thinner, the smaller the portion where the board is exposed at the end of the device, the more the mechanical stress on the board during mounting is eliminated, so the mounted electronic component It has been found that the mechanical damage on the surface is reduced, the occurrence of solder cracks is drastically reduced and the reliability is improved. For this reason, the side portion of the substrate corresponding to the end portion of the apparatus is opened, and the opened portion is filled with the resin of the prepreg. In addition, since this opening part cut | disconnects to an individual apparatus at a next process, it has a width | variety more than a cutting margin, a total length is below a cutting length, and one or more are formed.

  Further, helical inductors and organic electrolytic capacitors used for DC-DC power supply devices and the like still require a large area due to required characteristics. Therefore, in order to store them in a small mounting area, there is a case where the requirement for downsizing is not satisfied unless they are dealt with by stacking. The layout of the parts that meet this demand for miniaturization is the stacking of each part, and the terminal part is shifted to the left and right to connect to the circuit wiring, and each terminal is stacked to be orthogonal and connected to the circuit wiring. However, even if any three-dimensional stacking arrangement is adopted, it is necessary to increase the flow amount of the prepreg because the space in the mounting area becomes large. Therefore, a structure is adopted in which the amount of prepreg is smoothly supplied and adjusted in the mounting region by joining with a prepreg larger than these components without using a simple adhesive. In addition, when an inductor that is not shielded against electromagnetic waves is employed, the inductor can be joined using a prepreg sandwiched between a metal foil or a cloth to shield the electromagnetic wave. As the prepreg used here, a resin used for a general substrate such as a polyimide resin, an epoxy resin, or an aramid epoxy resin can be selected. Further, a resin containing glass cloth, aramid fiber, nylon non-woven fabric or glass cloth can be used.

  Here, when the prepreg is cured, pores are required for allowing the solvent to volatilize and escape the generated gas. However, as the volume of the prepreg increases, uniform curing becomes more difficult. Although the apparatus of the present invention is small, if the thickness of the prepreg exceeds 200 μm, it becomes difficult to handle in production. Therefore, a unit prepreg having a thickness of 200 μm or less was used.

Next, considering the electromagnetic wave shielding by the metal plate, the copper skin depth is 66 μm at a frequency of 1 MHz, 21 μm at 10 MHz, 7 μm at 100 MHz, and 2 μm at 1 GHz. In addition, a sheet in which metal powder or sendust-based material is kneaded, such as a metal foil such as copper or aluminum, a woven fabric such as nickel-coated carbon fiber or a wire mesh, can be used for the conductor layer. In order to cut off a high frequency of 1 MHz or higher using various materials, a thickness of a copper plate or more is required, and an average thickness of the material is 170 μm or less. Therefore, a good electromagnetic wave shielding effect can be obtained by selecting a material having a conductivity of 1 × 10 ⁴ Ω / □ or less for this conductor layer. The layer that insulates the conductor layer is formed by covering with a general resin film such as polyimide resin, epoxy resin, or aramid epoxy resin having a thickness of 50 μm or less in consideration of heat dissipation. That is, it can be produced by thermocompression bonding a thin film insulating film or by forming and curing a thin film coating film.

  When Sendust-based materials are used, there is no need to consider the connection with the GND electrode due to the characteristics of Sendust. However, when connecting from the conductor layer such as copper to the GND electrode of the substrate, the insulation-coated electromagnetic shielding plate is UV-coated. The electromagnetic shielding effect is increased by forming a bottomed hole having an outer diameter of about 100 μm from the electromagnetic shielding plate to the GND electrode of the circuit board using a YAG laser and filling with a conductive material. Further, an organic insulator may be applied on the conductive material in the hole and sealed. In addition, a predetermined hole is made in the insulating layer on the circuit board side of the electromagnetic wave shielding plate connected to the GND electrode, and a conductor such as copper is exposed, and the conductor is raised at the connection point with the electromagnetic wave shielding plate of the circuit board. When they are integrated, they may be connected by thermocompression bonding.

  When forming terminals in the device, connect it to the board in the device with solder or conductive adhesive using an IC terminal frame, etc., to expose the metal terminals from the device, or to reduce the number of parts A part of the electromagnetic shielding plate is electrically divided and made independent and connected to the circuit board circuit with a conductive material, or a conductive material is raised on the back of the circuit board with solder or conductive adhesive, and the conductive material is removed from the prepreg. This is done by exposing. When connected with a conductive material or exposed, it is used as a planar terminal.

  If there is a short circuit between the terminal of the device and the exposed conductor for shielding electromagnetic waves, an insulating layer is formed on the exposed conductor to perform insulation treatment, or the conductor is patterned in advance so that the conductor is not exposed. What is necessary is just to embed in the insulating layer of a board.

  Examples of the present invention will be described in detail below. In the following embodiments, a DC-DC power supply device is shown as an example of a DC-DC converter.

(Example 1)
FIG. 1 is a perspective view showing a part of the DC-DC power supply apparatus according to the first embodiment of the present invention. In actual manufacturing, a multi-layer substrate with a large number of pieces is manufactured. However, in order to make it easy to understand on the drawing, the substrate and terminals for one device are shown. FIG. 2 is a perspective view showing main parts constituting the DC-DC power supply device of FIG. As shown in FIG. 1, the DC-DC power supply device according to the first embodiment includes a power conversion semiconductor 8, a capacitor 9, an electronic component such as an inductor, and a terminal 11 on a circuit board 7 having openings 21, 22, and 23. Is mounted by soldering, and the prepreg 4 and the electromagnetic wave shielding plate 1 are joined together in this order on top and bottom.

  The DC-DC power supply device according to the first embodiment having such a configuration is manufactured as follows. First, as shown in FIG. 2A, both surfaces of a 9 μm-thick copper foil formed so as not to be exposed at the end when the power supply device is completed as a base material for electromagnetic wave shielding (electromagnetic wave shielding plate 1). A film having a polyimide resin with a thickness of 12 μm formed thereon was prepared. The copper foil having a thickness of 9 μm adopted this time exhibits an effective electromagnetic shielding effect against a high frequency of 10 MHz or more. Further, in order to connect to the GND electrode, a bottomed hole having an outer diameter of 100 μm was made in the polyimide resin connecting portion 33 on the substrate side using a UV laser to expose the copper foil. A conductive agent having a thickness of 30 μm was applied to the exposed portion of the copper foil, and was temporarily cured (cured). Moreover, the electromagnetic wave shielding plate 1 with the copper foil exposed has a terminal forming portion 12 on the side surface.

Next, as shown in FIG. 2 (c), a multilayer substrate (circuit substrate) 7 for forming a three-layer circuit comprising a 9 μm patterned copper foil and a polyimide resin film having a thickness of 15 μm is formed. did. Further, an opening was made from an area where no pattern was formed over an area corresponding to 30% of the total area of the substrate. When opening, do not make 30% equivalent at one place, and divide the size of one place into multiple places including sides so that it has an area of 0.01 mm ² or more. The aperture was opened by a micro press, UV laser or YAG laser. Actually, the portion and side where the pattern is not formed are processed and opened, and in particular, the two sides where the terminal is formed are divided into four so that the resin component contained in the prepreg flows, and the opening 22 is formed. The side where the terminal 11 was not formed was divided into three and opened to form the opening 23. Further, the opening 21 was formed on the substrate by opening five places so that the opening is also applied to the position where the component is mounted in the next process.

  Next, the circuit board 7 was used to solder-mount electronic components such as bare chips, capacitors, inductors, and the like of power conversion semiconductors. At the same time, soldering for connection to the electromagnetic wave shielding plate 1 was performed at a predetermined position of the GND electrode. When mounting these electronic components, it is also possible to mount the components on the lower surface side of the board.

  Next, an outline of electronic components to be mounted will be described. As the power conversion semiconductor, a synchronous rectification step-down DC-DC converter IC bare chip having a length of 2.5 mm, a width of 2.0 mm, and a height of 0.6 mm was used. Two capacitors having a B temperature characteristic of 2.2 μF multilayer ceramic capacitor having a length of 2.0 mm, a width of 1.25 mm, and a height of 0.7 mm were used. The inductor used was a 2 μH multilayer chip inductor having a length of 1.6 mm, a width of 0.8 mm, and a height of 0.7 mm. In addition, a small-capacity chip capacitor or chip resistor for temperature compensation having a length of 1.0 mm, a width of 0.5 mm, and a height of 0.5 mm was used.

  The volume ratio occupied by the electronic components in the mounting area on the substrate is about 60% even when close-packed, and the remaining 40% is a space area where no electronic components are mounted. It is necessary to replenish the resin uniformly by utilizing the fluidity of the prepreg that is not in the space region. If the resin is replenished only from one side of the prepreg, the thickness of the prepreg resin is often required to be 200 μm or more. If the thickness of the prepreg exceeds 200 μm, uniform curing is difficult. Therefore, it is necessary to use a prepreg having a thickness of 200 μm or less. Therefore, the shortage of resin to fill the part where electronic components are not mounted flows from the opening formed in the board using the fluidity of the resin contained in the prepreg placed on the lower surface of the board to the component mounting area on the board. refill. In this embodiment, as shown in FIG. 2 (b), two prepregs 4 made of polyimide resin having a thickness of 100 μm and laminated were joined from above and below the substrate.

The first prepared electromagnetic shielding substrate was placed on the upper and lower surfaces, and thermocompression bonded at 125 ° C. and a pressure of 9.8 × 10 ⁵ Pa (10 kgf / cm ² ). The device group was cut into a single-sided device (length 4.5 mm, width 3.2 mm) using a dicer.

  As described above, by using the prepreg, the power supply circuit as a whole is completed as an integrated device, and it is reduced in size by 42% compared to the conventional case of using the metal case or resin case of FIG. The effect of was obtained. Furthermore, the production yield was 100% (n = 100p), the conversion efficiency was 92%, a highly reliable power source with excellent power source performance was obtained.

(Example 2)
FIG. 3 is a perspective view showing a part of the DC-DC power supply device according to the second embodiment of the present invention. In actual manufacturing, a multi-layer substrate with a large number of pieces is manufactured, but in order to make it easy to understand on the drawing, it is shown with a substrate and a terminal for one device. FIG. 4 is a perspective view showing main parts constituting the DC-DC power supply device of FIG. As shown in FIG. 3, in the DC-DC power supply device according to the second embodiment, electronic components such as a power conversion semiconductor 8a, a capacitor 9a, and an inductor 10 are soldered onto a circuit board 7a having openings 21a, 22a, and 23a. The terminal 11a is provided at both ends of the long side, and the prepreg 4 and the electromagnetic wave shielding plate 1a are joined together in order above and below these so as to be integrated. A prepreg 5 having an electromagnetic wave shielding effect is disposed on the capacitor 9a, and an inductor 10 is disposed thereon. In this case, a prepreg 5 having a thickness of 270 μm or less including the conductor is used.

  The DC-DC power supply device according to the second embodiment having such a configuration is manufactured as follows. First, as shown in FIG. 4A, an epoxy resin is formed on at least the surface of a nickel-coated carbon fiber having a thickness of 20 μm coated as an electromagnetic shielding substrate (electromagnetic wave shielding plate 1a). A film having a thickness of 100 μm was prepared. Nickel-coated carbon fibers exhibit an effective electromagnetic shielding effect against high frequencies of 1 MHz or higher. Further, the electromagnetic wave shielding plate 1a on the substrate side has terminal forming portions 12a at both ends of the long side.

Next, as shown in FIG. 4C, a multilayer substrate (circuit substrate) 7a for forming a circuit composed of a patterned rolled copper foil and a polyimide resin film having a thickness of 15 μm was formed. . Furthermore, an opening was made over an area corresponding to 20% of the total area of the multilayer substrate from a portion where no pattern was formed. When opening, it was not divided into 20% equivalent at one place, and the size of one place was divided into a plurality of places including the side so as to have an area of 0.02 mm ² or more, and a mold was used. Opening was performed with a micro press, UV laser or YAG laser. Actually, the portion and the side where the pattern is not formed are processed and opened, and the side where the terminal is not formed is divided into two to form the opening 23a. Further, the side where the terminal is formed is divided into three and opened to form the opening 22a. Further, a hole having an outer diameter of 80 μm was formed in a portion where the circuit pattern was formed corresponding to the terminal forming portion. On the substrate, the opening 21a was formed by opening three places so that the opening is also applied to the position where the component is mounted in the next step.

  Next, using the circuit board 7a, electronic components other than the inductor, such as a power conversion semiconductor bare chip and a functional polymer aluminum electrolytic capacitor, and the terminal of the device were temporarily fixed. A thin film magnetic body in which an electromagnetic wave shielding plate sandwiched by 50 μm thick prepreg 5 is placed on a functional polymer aluminum electrolytic capacitor, and a CoFeSiB soft magnetic material and an epoxy organic film are laminated thereon. A helical inductor with 100 turns of dense winding with copper wire was temporarily fixed. It was mounted using solder after temporary fixing. Further, a conductive adhesive mixed with a metal was applied from the back surface of the substrate to the terminal formation portion, and in the next step, the prepreg 4a was penetrated to be part of the terminal formation. In forming this terminal, it is also possible to add solder instead of the conductive adhesive used this time.

  Next, an outline of electronic components to be mounted will be described. As a semiconductor for power conversion, a synchronous rectification step-down DC-DC converter IC with a bare chip having a length of 2.5 mm, a width of 2.0 mm, and a height of 0.6 mm was used. The capacitor used was a 2.2 μF functional polymer aluminum electrolytic capacitor having a length of 2.5 mm, a width of 2.2 mm, and a height of 0.3 mm. As the inductor, a helical inductor not having an electromagnetic wave shielding structure of 2 μH and having a length of 2.5 mm, a width of 2.0 mm, and a height of 0.3 mm was used. In addition, a small-capacity chip capacitor or chip resistor for temperature compensation having a length of 1.0 mm, a width of 0.5 mm, and a height of 0.5 mm was used.

  The volume ratio occupied by the electronic components in the mounting area on the substrate is about 60% even when close-packed, and the remaining 40% is a space area where no electronic components are mounted. It is necessary to replenish the resin uniformly by utilizing the fluidity of the prepreg that is not in the space region. Therefore, the shortage of resin for filling the part where the electronic component is not mounted is from the opening formed in the substrate using the fluidity of the resin contained in the prepreg arranged on the lower surface of the substrate to the component mounting region on the substrate. Fluid replenishment. In this embodiment, as shown in FIG. 4B, a prepreg 4 made of a polyimide resin having a thickness of 100 μm stacked on the upper side of the substrate and a polyimide resin having a thickness of 100 μm on the lower side of the substrate is used. It joined using the prepreg 4a.

The electromagnetic shielding plates prepared first were placed on the upper and lower surfaces, and thermocompression bonded at 125 ° C. and a pressure of 9.8 × 10 ⁵ Pa (10 kgf / cm ² ). Then, a hole is made using UV laser or YAG laser at both ends of the long side of the substrate, and a conductive adhesive is applied to the formed hole so that conduction at the terminal forming portion can be reliably connected, After connecting with the circuit pattern of the substrate, it is dried. Also, solder can be used in place of the conductive adhesive as described above, and the terminal can be formed by exposing the conductor forming the terminal by grinding only the portion where the conductor is raised. . In addition, this time, a hole having an area twice the diameter of the hole for the terminal formed in the circuit board is made in the electromagnetic wave shielding plate so that the terminal does not contact the conductor layer in the electromagnetic wave shielding plate, and the prepreg flows. It was designed to insulate the conductor layer in the electromagnetic shielding plate. However, if there is no insulation reliability, it is preferable to cover the conductor layer in the electromagnetic wave shielding plate with an organic insulating material in advance. Thereafter, this completed device group was cut into individual devices (length 4.5 mm, width 3.0 mm) using a dicer.

  Thus, by using the prepreg, it is finished as an apparatus in which the entire power circuit is integrated, and the volume ratio is reduced by 46% compared to the case where the conventional metal case or resin case of FIG. 5 is used. The effect of miniaturization was obtained. Furthermore, the production yield was 100% (n = 100p), the conversion efficiency was 90%, the reliability was high, and an excellent power source as power source performance was obtained. By configuring as in this embodiment, an inductor having no structure for shielding electromagnetic waves can be used.

  As mentioned above, although the example of the DC-DC power supply apparatus was shown, this invention is applicable also to the apparatus which mounts various electronic components besides this.

The perspective view which crushes and shows a part of DC-DC power supply device in Example 1 of this invention. The perspective view of the main components which comprise the DC-DC power supply device of FIG. FIG. 2A is a perspective view of an electromagnetic wave shielding plate. FIG. 2B is a perspective view of the prepreg. FIG. 2C is a perspective view of the circuit board. The perspective view which crushes and shows a part of DC-DC power supply device in Example 2 of this invention. The perspective view of the main components which comprise the DC-DC power supply device of FIG. FIG. 4A is a perspective view of an electromagnetic wave shielding plate. FIG. 4B is a perspective view of the prepreg. FIG. 4C is a perspective view of the circuit board. The perspective view which crushes and shows a part of conventional DC-DC power supply device using a metal case.

Explanation of symbols

1, 1a Electromagnetic wave shielding plate 2 Conductive layer 3 Resin 4, 4a, 5 Prepreg 7, 7a, 117 Circuit board 8, 8a Power conversion semiconductor 9, 9a Capacitor 10 Inductor 11, 11a, 111 Terminal 12, 12a Terminal formation part 14 , 14a, 114 (DC-DC power supply) devices 21, 21a (on the substrate) openings 22, 22a (on sides where terminals are formed) openings 23, 23a (on sides where no terminals are formed) openings 33 ( Connection point 113 (with GND electrode) Metal case 140 Electronic component

Claims (6)

  A method of manufacturing a DC-DC power supply apparatus, in which an electromagnetic wave shielding plate is joined by thermocompression bonding via a prepreg to both surfaces of a circuit board on which electronic components including an inductor and a capacitor are mounted or built-in. A method of manufacturing a DC-DC power supply device, comprising the step of providing an opening having a size that allows the prepreg to flow when the electromagnetic wave shielding plate is joined.   2. The method of manufacturing a DC-DC power supply device according to claim 1, further comprising a step of forming a plurality of devices by cutting.   The opening formed on one side of the circuit board having a size capable of manufacturing the plurality of devices has a width equal to or larger than a cutting margin, a total length is equal to or less than the cutting length, and is at least one. The method of manufacturing a DC-DC power supply device according to claim 2.   The method for manufacturing a DC-DC power supply device according to any one of claims 1 to 3, wherein the prepregs are bonded in combination with a thickness of 200 µm or less.   The electromagnetic shielding plate is a sheet or non-woven fabric composed of a conductive layer made of foil, wire, or woven metal, and an insulating layer made of a resin or metal oxide in which the conductive layer is insulated. 5. The method of manufacturing a DC-DC power supply device according to claim 1, wherein an average thickness of the layers is 170 μm or less, and an average thickness on one side of the insulating layer is 50 μm or less.   The DC-DC power supply according to any one of claims 1 to 5, wherein the electronic component is arranged by being stacked up and down via a prepreg having a thickness of 270 µm or less with a conductor having an electromagnetic wave shielding effect interposed therebetween. Device manufacturing method.

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