JPH10209649A - Metal case and method of manufacturing the metal case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small and low-price metal case by reducing the number of manufacturing processes and realizing efficient manufacture of the metal case in a short period without unnecessary molds. SOLUTION: In a manufacturing method, a metal case 5 which contains a board on which an electronic part is mounted and which is filled with resin, has a box shape, comprising a bottom plate 28 and a side plate 29 bent into a square prism around the bottom plate 28. The gaps in the metal case 5 including the gap between the bottom plate 28 and the side plate 29 are sealed by attaching a resin film 31 to the gaps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to various electronic devices such as a computer device, a television, a video, and the like. The present invention relates to a metal case for an electronic component or an electric component and a method for manufacturing the metal case.

[0002]

2. Description of the Related Art A conventional example will be described below. §1: Description of Metal Case Conventionally, various electronic devices and electric components such as computer devices, televisions, and videos have been used as circuit components constituting the devices.
When such a component is mounted on the device, generally, the component is mounted on a motherboard (printed circuit board),
This motherboard was attached to the device.

Various components such as discrete components, module components, and other composite components are used as components to be mounted on the motherboard. Of these, components in a metal case are also used. Was.
The components in the metal case are generally used for performing an electrostatic shield or a magnetic shield, but may be simply a dustproof case.

A DC-DC converter, for example, has been known as an example of such a component in a metal case. In the DC-DC converter, electronic components (circuit elements) such as transistors, resistors, coils, capacitors, and diodes that constitute the DC-DC converter are mounted on a printed circuit board, and the printed circuit board is stored in a metal case. A DC-DC converter in a metal case is obtained by filling a casting resin from above and solidifying the resin. Hereinafter, a metal case used for such a metal case-containing component will be described.

[0005] §2: Description of the manufacturing process of the metal case--see FIG. 6 FIG. 6 is an explanatory diagram of the manufacturing process of the metal case in the conventional example. Hereinafter, the manufacturing process of the metal case will be described with reference to FIG. When manufacturing the metal case, the metal case is manufactured through the following steps,
In this case, it is manufactured mainly by drawing using a die by a processing machine employing a progressive processing method (progressive processing method).

Process: Hoop material 1 made of a long metal material
The hoop material 1 is pulled out from the material supply device wound with the, and is positioned at a predetermined position of the processing machine. Then, a first drawing process is performed at the position of the first drawing portion 2 of the hoop material 1, and the drawing is performed shallowly according to the shape of the metal case.

Step: The same second step as the first drawing section 2
At the position of the drawing portion 3, a second deeper drawing process is performed. Step: The drawing process is performed as described above, and when the shape of the metal case is almost completed, the metal case is dimensioned by a shaping press process. Thereafter, when the shaping of the metal case is completed, a portion to be the metal case is cut off from the hoop material by press working. In the subsequent steps, a single press working separate from the progressive processing is performed on the cut-off portion (this is referred to as a “metal case”). The metal case 5 cut off from the hoop material 1 in this step becomes a bottomed prismatic case (box-shaped case) having one end opened.

Step: The metal case 5 cut off from the hoop material 1 is subjected to side trim processing by a press machine to complete the metal case 5.
In this step, the metal case 5 is set at a predetermined position of a processing machine in order to perform side trim processing. Then, bossing or the like is performed on the side surface of the metal case 5 by side trimming.

Step: Side trimming is performed on the metal case 5 set at a predetermined position, and foot pieces 6 for case soldering are formed at two places on the side surface of the metal case 5. Step: Side trimming is again performed on another side surface of the metal case 5 to cut off two cutout portions 7 on the side surface of the metal case 5.

Step: Side trimming is performed on the side surface of the metal case 5, and two of the four corner projections of the metal case 5 are formed.
Cut out the protruding portions 8 at several places. Step: Side trimming is performed on the side surface of the metal case 5, and the remaining protruding portions 8 of the metal case 5 are cut. Thus, the side trimming of the metal case 5 is completed.

Step: The metal case 5 on which the side trim processing has been completed is subjected to a solderable plating process, and the metal case 5 is completed. §3: Description of the printed circuit board storage process—see FIG. 7 FIG. 7 is an explanatory view when a metal case is used in the conventional example.
9 is a diagram illustrating a relationship between the R of the metal case and the printed circuit board, and FIG. The metal case 5 completed as described above has a large number of circuit components (circuit elements).
Is stored. In this case, the process of storing the printed circuit board 12 is performed as follows.

First, a completed metal case 5, a printed circuit board 12 on which circuit components are mounted, a casting resin (a resin put in a container), and the like are prepared. The printed circuit board 12
Used is provided with a circuit connection lead terminal. Then, with the open end of the metal case 5 facing upward, the printed circuit board 12 is housed in the metal case 5 from the open end side, and set at a predetermined position in the metal case 5.

Thereafter, the casting resin 14 is placed from the opening end side.
To fill the inside of the metal case 5 with the casting resin 14. Next, when the casting resin 14 is dried and cured, components in a metal case such as a DC-DC converter are completed. The casting resin 14 is used for fixing a printed circuit board, circuit components, and the like and releasing heat.

When the printed circuit board 12 is housed in the metal case 5, as shown in FIG. 7B, the printed circuit board 12 is placed on a boss 10 provided on the side surface of the metal case 5.
The printed circuit board 12 is dropped on the bottom of the metal case 5 and fixed, as shown in FIG. 7C.

When the printed circuit board 12 is accommodated in the metal case 5 and the cover 13 is put on after the casting resin 14 is filled, a hole 11 is formed in the metal case 5 and the printed circuit board 12 is inserted into the hole 11. The cover is fixed by locking the locking pieces 15 provided at both ends of the cover.

As described above, since the metal case 5 is integrally manufactured by drawing, R is formed around the bottom of the metal case 5 and at the four corners of the side surface. Is done). That is, the metal case 5 is formed in a prismatic shape with a bottom in order to accommodate the rectangular printed circuit board 12 therein. However, since the metal case 5 is manufactured by drawing, the above-mentioned portion requires R. Become.

For this reason, as shown in FIG. 7D, when the rectangular printed circuit board 12 is stored as it is, the clearance becomes large due to the R. That is, since the Rs are formed at the four corners of the metal case 5, if the printed circuit board 12 is rectangular, the corners will hit the R portions, and the space in the metal case 5 cannot be used effectively.

Therefore, the printed circuit board 12 housed in the metal case 5 is processed as follows. : Metal case 5
Printed circuit board 12 in a push-back method corresponding to R
make. C-chamfering is performed on the four corners of the printed circuit board 12 and V-groove cutting is performed on the four corners of the printed circuit board 12.

[0019]

The above-mentioned prior art has the following problems. (1): Conventionally, in order to manufacture a metal case 5 for an electronic component, a flat metal plate is drawn, the outer shape is pressed and cut off, and a printed circuit board is placed on a side surface of the cut-off metal case 5. To form bosses (protruding portions) for forming the holes or to form foot pieces for soldering the case at the open ends. Thereafter, a plating process capable of being soldered was performed, and the metal case 5 was finally completed.

As described above, in order to form the metal case 5 into the final shape, generally, a drawing process is performed from a flat plate-shaped metal plate in two to three steps, side trimming is performed, and unnecessary portions are removed. The metal case 5 as a final structure can be manufactured through the steps of bossing of the side surface, trimming of foot pieces for soldering, side cutting, and cutting of four corners, and further plating.

Therefore, it takes many steps (for example, 8 to 10 steps) to manufacture the metal case 5, the number of manufacturing steps of the metal case 5 is large, it takes time and effort, and the metal case 5 is expensive. Had become.

(2) Conventionally, when manufacturing a metal case 5 for an electronic component, since a flat metal plate is drawn and the outer shape is processed by progressive processing until it is cut off by cutting, it is relatively simple. Can be processed. However, after that, a step of forming a boss for mounting a printed circuit board on a side surface of the cut-off metal case 5 or performing a side trimming process for forming a case soldering foot at an open end portion is performed. It is performed in a single step, not in progressive processing. Therefore, a large number of independent steps are required for processing the metal case 5 after being cut off as described above, which is troublesome and time-consuming, and increases the cost of the metal case 5.

(3): Since the conventional metal case 5 is manufactured by drawing, the periphery of the bottom of the metal case 5 and the four corners of the side surface are formed at R. Therefore, if the rectangular printed circuit board 12 is stored as it is, the clearance becomes large due to the aforementioned R. That is, since the R is formed at the four corners of the metal case 5 and the like, if the printed board 12 is rectangular, the corners hit the R portion, and the space in the metal case 5 cannot be used effectively. For this reason, if the size of the printed circuit board 12 is kept constant, the size of the metal case 5 becomes large, which leads to an increase in the size of components.

(4): To deal with R of the metal case 5,
Printed circuit board 12: Printed circuit board 12 is produced by a push-back method corresponding to R of metal case 5. : Chamfering the four corners of the printed circuit board 12
In other words, V-grooves were cut at the four corners of No. 2 and the like.

However, in the above method, the printed circuit board 1
The production of 2 requires extra labor and time, and is expensive. In the above-described method, a mold is required for performing the C-chamfering, which requires extra labor and time, resulting in an increase in cost.

The present invention solves such a conventional problem,
An object of the present invention is to reduce the number of manufacturing steps of a metal case and to efficiently manufacture a metal case in a short time without requiring an extra mold. Another object of the present invention is to realize a small and inexpensive metal case by increasing the storage area of the printed circuit board by forming the corner of the metal case at a substantially right angle.

[0027]

FIG. 1 is a diagram illustrating the principle of the present invention. The present invention is configured as follows to achieve the above object. (1): In the metal case 5 for accommodating the board on which the electronic components are mounted and filling the casting resin,
Is formed in a prismatic shape with a bottom by a bottom plate portion 28 and a side plate portion 29 which is bent in four directions around the bottom plate portion 28 to form a gap in the metal case 5 (a slit or the like which can be a contact portion between the side plate portions 29). ), A resin film 31 of a resin for the seaming was adhered and seamed.

(2): In the metal case of (1), the filling resin includes a shielding material (conductor powder, magnetic powder, or a powder obtained by mixing both), and a resin film of the filling resin A shield (electrostatic shield, magnetic shield, or electromagnetic shield) is provided by 31.

(3): In the method of manufacturing the metal case 5 for accommodating the substrate on which the electronic components are mounted and filling the casting resin, the metal plate (for example, the hoop 1) is used to remove the bottom plate 28 and the bottom plate 28 from the metal plate. A first step of manufacturing a bottomed prismatic metal case 5 including a side plate portion 29 bent in four directions around a bottom plate portion 28, and a gap between the manufactured metal case 5 (contact between the side plate portions 29); And the second step of forming the resin film 31 of the sealing resin.

(Operation) The operation of the present invention based on the above configuration will be described with reference to FIG. As shown in FIG. 1A, a hoop material 1 made of a metal material is pulled out from a material supply device and positioned at a predetermined position of a processing machine. Then, a first piercing process (drilling process) is performed on a predetermined position of the hoop material 1 to cut the cut portions 21 and 22. Subsequently, the other cut portions 24 and 25 are cut by the second piercing. Next, the metal case 5 is dimensioned into a shape of the metal case 5 by forming cutting, and the metal case 5 is cut off from the hoop material 1. Thus, the metal case 5 as a semi-finished product can be manufactured.

In this case, a metal case 5 having a bottomed prismatic shape as shown in FIG. 1B can be manufactured by the forming cut process.
It is composed of four side plate portions 29 connected to the bottom plate portion 28, and the four side plate portions 29 are bent at right angles to the bottom plate portion 28, respectively. The metal case 5 cut off from the hoop material 1 as described above is plated with a solderable material.

In this case, since the four corners of the metal case 5 are only brought into contact with the side plate 29, there are gaps (slits) in the contact portions. Therefore, when the casting resin is filled in this state, the casting resin may leak from the gap. Therefore, it is necessary to close the gap, and a seaming process is performed in a subsequent step.

In this seaming, for example, as shown in FIG. 1B, the metal case 5 plated in the above-mentioned process is used.
Inside, using a dispenser 27,
(A solution obtained by diluting the resin for sealing with a diluting liquid) is added dropwise. The sealing resin liquid 30 dropped into the metal case 5 in this manner spreads to the corners in the metal case 5 due to surface tension (wet spread), and is further opened to the gap between the side plate portions by capillary action. The resin film 31 spreads to the upper part on the end side.
make.

In this way, the resin film 31 made of the filling resin adheres to all the slits in the metal case 5 to completely fill the gap in the metal case 5. After that, when the resin film 31 of the sealing resin is dried and hardened, the metal case 5 with the sealing is completed.

In addition, in the above-mentioned seaming, if the seaming is performed by using a seaming resin using a conductor powder, a magnetic body powder, or a mixture of both the conductor powder and the magnetic body powder, the electrostatic shielding, Magnetic shielding or electromagnetic shielding can be performed.

As described above, compared to the conventional example,
The number of steps for manufacturing the metal case 5 can be reduced, and the metal case 5 can be efficiently manufactured in a short time without requiring an extra mold. In addition, since the corners of the metal case 5 can be formed at substantially right angles, it is possible to reduce the clearance and increase the use area of the printed circuit board. Therefore, an inexpensive metal case can be realized.

[0037]

Embodiments of the present invention will be described below in detail with reference to the drawings. §1: Description of the manufacturing process of the metal case ... see FIG. 2 FIG. 2 is a diagram illustrating the manufacturing process of the metal case, where A is a diagram showing the manufacturing process, and B is a metal case separated from the hoop material. FIG. Hereinafter, the manufacturing process of the metal case will be described with reference to FIG.

The metal case described below is an example of the same metal case for electronic components as the metal case described in the above-mentioned conventional example, but the manufacturing method and structure of the metal case are different. In the present embodiment, when manufacturing a metal case, it is possible to manufacture the metal case by simple press working without using the conventional drawing.

Step 1: In the first step, the hoop material 1 is pulled out from a material supply device in which the long hoop material 1 made of a metal material is wound, and is positioned at a predetermined position of a processing machine. Then, perforations 20 are formed on both sides of the hoop material 1 by punching. Thereafter, the hoop material 1 is transported to a position required in each step using the feed hole 20 and positioned.

Step 2: In the next step, the cut portions 21 and 22 are cut by first piercing (drilling). In this case, an uncut portion 23 having a predetermined width is left between the cut portions 21 and 22 so that the punched portion does not fall off the hoop material 1.

Step 3: Subsequently, the other cut portions 24 and 25 are cut by the second piercing (piercing). Step 4: Next, while performing dimensioning processing to the shape of the metal case 5 by forming cut processing, the cut portion 2 is formed.
6 is cut, and the metal case 5 is cut off from the hoop material 1. Thus, the metal case 5 as a semi-finished product having the shape as shown in FIG. 2B can be manufactured.

In this case, the forming cut process results in a bottomed prismatic metal case 5 as shown in FIG. 2B. The metal case 5 is connected to the bottom plate 28 and the bottom plate 28. The bottom plate 28 is formed by bending the four side plate portions 29 at right angles to each other.

Therefore, since the four corners of the metal case 5 are only brought into contact with the side plate 29, there are gaps (slits) in the contact portions. Therefore, when the casting resin is filled in this state, the casting resin may leak from the gap. Therefore, it is necessary to close the gap, and in the subsequent process, a later-described seaming process is performed.

Step 5: The metal case 5 cut off from the hoop material 1 in the step 4 is plated with a solderable material. Step 6: metal case 5 plated as described above
Apply seaming from inside. By this seaming process,
The metal case 5 is completed by covering the four corners of the metal case 5 to prevent leakage of the filling resin. The material of the metal case 5 may be a conductive material or a material obtained by mixing a magnetic material with a conductive material.

§2: Explanation of seaming process of metal case
・ See FIGS. 3 and 4 FIG. 3 is an explanatory view of the metallizing process of the metal case (No. 1), FIG.
FIG. 4 is an explanatory view (No. 2) of a metallizing step of a metal case. Hereinafter, the metallizing step of the metal case will be described with reference to FIGS.

As shown in FIG.
A metal case 5 having a bottomed prism shape as shown in FIG. 3B is formed. The metal case 5 includes a bottom plate portion 28 and four side plate portions 29, and has four sides with respect to the bottom plate portion 28. Each of the face plates 29 is bent at right angles.

Therefore, since the four corners of the side surface of the metal case 5 are only brought into contact with the side plate 29, there are gaps (slits) in the contact portions. Therefore, when the casting resin (casting material) is filled in the metal case 5 in this state, the casting resin may leak from the gap. Therefore, it is necessary to close the gap, and the following step is performed in the subsequent steps.

As the seaming process, a method of closing the gap by soldering, a method of closing the gap by welding, and a method of applying an adhesive to the gap to close the gap can be considered. However, in the above-mentioned method, a soldering device or a welding device is required, and it takes time and effort, and the cost of the metal case 5 increases. In the above-mentioned method, not only it takes time and effort, but also it is difficult to apply an adhesive to an extremely narrow gap to perform perfect seaming. Therefore, the following seaming is performed.

As shown in FIG. 3A, using a dispenser 27, a resin filling liquid 30 is dropped into the metal case 5 plated in the above step. In this case, the sealing resin liquid 30 may be dropped almost at the center of the metal case 5. The filling resin liquid 30 is a resin liquid obtained by diluting the filling resin with a diluting liquid.
When 0 is dropped into the metal case 5, it spreads rapidly to the corners in the metal case 5 due to surface tension (wet spread),
Further, the resin film 31 is spread in the gap between the side plate portions 29 to the upper portion on the open end side by capillary action.

In this manner, the resin film 31 of the filling resin spreads in all the gaps in the metal case 5 to completely fill the gaps in the metal case 5. Thereafter, when the resin film 31 of the sealing resin liquid is dried and hardened, the metal case 5 in which the gap is completely sealed is completed. As the sealing resin liquid 30, the following resin which has been conventionally used for moisture-proof coating is diluted with a diluent and used.

That is, the filling resin liquid 30 is used after diluting the filling resin with a diluting liquid (diluent). The filling resin is sold, for example, by Daiichi Kogyo Seiyaku Co., Ltd. Polyflex M-50 (trade name) (urethane resin) is used. In addition, methylene chloride is used as the diluent (diluent).

The seaming process is performed as described above, and the resin film 3 is formed.
A printed circuit board on which circuit components are mounted is housed in a metal case 5 that is dried and cured, and a casting resin is filled from above, and the casting resin is cured. (For example, DC-DC)
Converter) is completed. This resin-filled part 32 is
For example, it is mounted on the motherboard 33.

The following methods are used for the above-mentioned seaming. In the first method, as shown in FIG.
Is dropped into the metal case 5, and is dried in a state where the resin film 31 of the resin liquid for the seaming is spread in the gap of the metal case 5,
This is a curing method (dispenser method shown in FIG. 3). : In the second method, as shown in FIG.
This is a method in which the resin film of the filling resin spreads in the gaps, and then is dried and cured (spray method).

In the third method, as shown in FIG. 4C, a resin filling liquid 30 is placed in a container 35, and the metal case 5 is immersed in the liquid filling 30 in the container 35.
Thereafter, the metal case 5 is pulled out of the container 35 and dried.
This is a curing method (dip method).

§3: Description of Printed Circuit Board Storage Process—See FIG. 5 FIG. 5 is an explanatory diagram when a metal case is used. A printed circuit board on which a large number of circuit components are mounted is stored in the metal case 5 completed as described above. The storing step of the printed circuit board is performed as follows. First, a metal case 5 completed as described above, a printed circuit board 12 on which circuit components are mounted, a casting resin, and the like are prepared. The printed circuit board is provided with a lead terminal 37 for circuit connection.

Then, the printed board 12 is put into the metal case 5 from the opening end side with the opening end of the metal case 5 facing upward, and set at a predetermined position. Thereafter, the inside of the metal case 5 is filled with the casting resin 14 by injecting the casting resin 14 from the opening end side. Next, the casting resin 14 is dried and cured to complete an electronic component in a metal case such as a DC-DC converter. Note that the casting resin is used for fixing and heat radiation of a printed circuit board, a circuit element, and the like.

As described above, when the printed circuit board 12 is housed in the metal case 5, a method of dropping and fixing the printed circuit board 12 to the bottom plate portion 28 of the metal case 5 as shown in FIG. ,: As shown in FIG.
There is a method of mounting and fixing both ends of the printed circuit board 12 on the boss 10 provided on the side plate 29 of the metal case 5. In the above method, the bottom plate portion 28 of the metal case 5 is used.
An insulating plate 36 is provided between the
Insert

The metal case 5 is manufactured not by drawing but by piercing and forming cut. Therefore, the periphery of the bottom plate 28 of the metal case 5 and the side plate 2
The four corners of No. 9 are formed at substantially right angles, and no R is formed as in the conventional example. Therefore, the inside of the metal case 5 can be used effectively.

§4: Other explanations (1): A conductive fine powder (for example, aluminum powder, carbon fine powder, etc.) is mixed with the resin filling material, and the resin filling liquid containing conductive fine powder is mixed. At 30, the metal case 5 may be seamed. In this case, a resin film 31 made of a sealing resin containing conductive fine powder is provided on the corner of the metal case 5.
Adheres, so that the electrostatic shielding effect of the metal case 5 is enhanced.

(2): Fine powder of a magnetic substance (for example, iron powder, nickel powder, etc.) is mixed with the resin liquid for filling, and the metal case 5 is coated with the resin liquid containing fine powder of magnetic substance. May be performed. In this case, a resin film 31 made of a seaming resin containing a fine powder of a magnetic material is provided at the corner of the metal case 5.
Is attached, so that the magnetic shielding effect of the metal case 5 is enhanced.

(3) Electromagnetic shielding of the metal case 5 by mixing a conductive fine powder and a fine powder of a magnetic substance or a fine powder having both properties with the resin liquid for filling. The effect can be enhanced.

[0062]

As described above, the present invention has the following effects. (1): Since the conventional drawing process is not used, the number of manufacturing steps of the metal case can be reduced as compared with the conventional example, and an extra mold is not required, so that it is efficient in a short time and A metal case can be manufactured at low cost.

(2): Since the conventional drawing process is not used, no R can be formed at the corner of the metal case. That is, since the corners of the metal case are formed at substantially right angles, the clearance can be reduced, the use area of the printed board can be increased, and the printed board can be minimized. Therefore, a small and inexpensive metal case can be realized.

(3): Since the metal case is formed in a bottomed prism shape by the bottom plate and the side plate bent in four directions around the bottom plate, the corners of the metal case are formed at substantially right angles. For this reason, it is not necessary to perform processing such as C-chamfering on the printed circuit board, and no extra mold is required, so that a small and inexpensive metal case can be manufactured.

(4): The shielding effect of the metal case (the effect of the electrostatic shield, the magnetic shield, and the electromagnetic shield) is obtained by mixing conductive fine powder, magnetic fine powder, and the like with the resin for the seaming. It is possible to increase.

(5): The metal case can be covered with a simple tool such as a dispenser or spray, so that the metal case can be manufactured at low cost. Also,
Even if there is a slit in the metal case, the slit can be completely sealed by the sealing process, so that the casting resin does not leak to the outside when the casting resin is injected.

(6) Since the metal case is subjected to the seaming, the metal case can be manufactured by a simple process of punching out from a metal plate.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process of the metal case in the embodiment.

FIG. 3 is an explanatory view (No. 1) of a metal case filling step in the embodiment.

FIG. 4 is an explanatory view (No. 2) of a metal case filling step in the embodiment.

FIG. 5 is an explanatory diagram of an example of using a metal case in the embodiment.

FIG. 6 is an explanatory view of a metal case manufacturing process in a conventional example.

FIG. 7 is an explanatory view when a metal case is used in a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hoop material 10 boss 11 hole 12 printed circuit board 13 cover 14 resin for casting 15 locking piece 20 feed hole 21, 22, 24 to 26 cut part 28 bottom plate part 29 side plate part 30 resin liquid for seaming 31 resin film 32 resin Filling parts 34 spray

Claims (3)

[Claims] 1. A metal case for accommodating a board on which electronic components are mounted and filling with a casting resin, wherein the metal case includes a bottom plate portion and side plate portions bent around the bottom plate portion in four directions. A metal case having a bottomed prismatic shape, wherein a resin film of a sealing resin is adhered to a gap in the metal case including a contact portion between the side plate portions, and the metal case is seamed. 2. The metal case according to claim 1, wherein the sealing resin includes a shielding material, and shielding is performed by a resin film of the sealing resin. 3. A method of manufacturing a metal case for accommodating a substrate on which electronic components are mounted and filling a casting resin, comprising: a bottom plate portion formed from a metal plate material; and a side plate portion bent four-sided around the bottom plate portion. A first step of manufacturing a metal case having a bottomed prism shape and a second step of forming a resin film with a resin for filling in a gap between the manufactured metal cases and filling the gap. A method for manufacturing a metal case, comprising: