JP3933852B2 - Shield device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shield device that shields electronic components.
[0002]
[Prior art]
Conventional Example 1
FIG. 11 is a perspective view showing a conventional shield device for module parts, and FIG. 12 is a sectional view taken along the line DD of FIG.
In the figure, 1 is an electronic circuit board, 2 is an electronic component mounted on the electronic circuit board 1, 3 is a shield case covering the entire electronic component 2, and 1d is a semicircular shape for soldering the shield case 3. Through-holes 1e are external electrodes of the module, and 3d are soldering protrusions of the shield case 3.
[0003]
In the example of FIG. 11, the soldering projections 3 d provided at both ends of the shield case 3 are soldered to the semicircular through holes 1 d provided in the electronic circuit board 1 to function as a shield device.
[0004]
Conventional Example 2
FIG. 13 is a perspective view showing another conventional shield device for module parts, and FIG. 14 is a cross-sectional view taken along the line EE of FIG.
In the figure, 1 is an electronic circuit board, 2 is an electronic component mounted on the electronic circuit board 1, 3 is a shield case covering the entire electronic component 2, and 1 b is soldering the shield case 3 on the electronic circuit board 1. The pads 1e are external electrodes of the module.
[0005]
As shown in FIG. 13, there is also used a device that functions as a shield device by soldering the shield case 3 directly to the pad 1b provided on the electronic circuit board 1 without providing projections on both ends of the shield case 3. ing.
[0006]
Conventional Example 3
FIG. 15 is a perspective view showing still another conventional shield device for module parts, and FIG. 16 is a sectional view taken along line FF in FIG.
In the figure, 1 is an electronic circuit board, 2 is an electronic component mounted on the electronic circuit board 1, 3 is a plurality of shield cases covering the electronic component 2, and 1 e is an external electrode of the module.
[0007]
As shown in FIG. 15, a plurality of shield cases 3 are used, and each of them is soldered to the electronic circuit board 1 to function as a shield device that shields circuit blocks in the module.
[0008]
[Problems to be solved by the invention]
Since the conventional shield device for module parts is configured as described above, there are the following problems.
(1) In the shield device for module parts of Conventional Example 1, since it is necessary to divide the through hole 1d in order to provide the semicircular through hole 1d in the electronic circuit board 1, the manufacturing cost of the electronic circuit board 1 is increased. There was a problem that occurred.
In addition, after soldering the electronic component 2 on the electronic circuit board 1 in order to solder the projection 3d of the shield case 3 to the electronic circuit board 1, the shield case 3 is attached separately, and soldering or cream soldering is performed. A soldering process such as supply to the semicircular through hole 1d and reflow soldering is necessary, which increases the manufacturing cost due to the complicated manufacturing process, and heat stress is applied to the electronic component 2 mounted in the module. There were problems such as a decrease in reliability due to the addition of a large amount, or an increase in cost of parts for improving heat resistance.
[0009]
(2) In the shield device for module parts according to the conventional example 2, since the shield case 3 cannot be positioned with respect to the electronic circuit board 1, the electronic part 2 on the electronic circuit board 1 is Therefore, there is a drawback that the module becomes large.
Also, since the electronic component 2 mounted on the electronic circuit board 1 and the shield case 3 need to be mounted without contact, the height of the module is the maximum height of the electronic component 2 mounted on the electronic circuit board 1. There was a problem that would be higher.
[0010]
(3) In the shield device for module parts of the conventional example 3, when shielding between circuit blocks in the module, a plurality of shield cases 3 are required, and the manufacturing cost increases due to the complicated manufacturing process, and the part cost increases. There was a rising problem.
Further, it is necessary to provide a space between the shield cases 3 and so that the shield case 3 and the electronic component 2 do not come into contact with each other, resulting in problems such as an increase in the size of the module.
[0011]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a shield device for a module component that is small, short, and inexpensive in manufacturing process.
[0012]
[Means for Solving the Problems]
The shield device according to the present invention has an electronic circuit board on which an electronic component is mounted on one surface, a facing surface facing the one surface, and an opening at a position corresponding to the electronic component on the facing surface. A shield case soldered to the electronic circuit board, wherein the distance from the one surface of the electronic circuit board to the opposing surface of the shield case is the electron relative to the one surface of the electronic circuit board The wall surface surrounding the opening of the shield case and the surface of the electronic component disposed at a position corresponding to the opening are opposed to each other, and the distance from the surface to the wall surface is less than the height of the component It is the distance that can keep the shielding effect .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Reference Example 1
Reference Example 1 of the present invention will be described below with reference to the drawings.
1 and 2 are views showing a reference example 1. FIG. 1A is a perspective view showing a process of assembling the module, FIG. 1B is a perspective view showing a completed form of the module, and FIG. FIG.
In FIG. 1, 1 is an electronic circuit board, 1a is a notch provided in the electronic circuit board 1, 1b is a pad for soldering a shield case, and 1e is an external electrode of the module. Reference numeral 2 denotes an electronic component mounted on the electronic circuit board 1, 3 denotes a shield case, and 3 a denotes positioning protrusions provided at both ends of the shield case 3.
[0014]
After mounting the electronic component 2 on the electronic circuit board 1, the positioning projection 3 a of the shield case 3 is attached using the notch 1 a provided on the electronic circuit board 1 as a guide, and the shield case 3 together with the electronic component 2 is mounted on the electronic circuit board 1. Soldered to the pad 1b for soldering of the shield case.
[0015]
The dimensional difference between the notch 1 a provided on the electronic circuit board 1 and the positioning projection 3 a of the shield case 3 is determined by the accuracy of the notch 1 a processing and the processing accuracy of the shield case 3. For example, when the dimension of the positioning projection 3a is 3 ± 0.1 mm and the machining accuracy of the notch 1a is ± 0.1 mm, the dimension of the notch 1a is 3.1 mm + 0.2 which is the maximum dimension of the positioning projection 3a. Set to / -0mm.
[0016]
In this case, the maximum deviation of the shield case 3 is the case where the notch 1a is the maximum and the positioning protrusion 3a is the minimum,
(3.3-2.9) /2=0.2 mm.
Since the positioning protrusions 3a provided at both ends of the shield case 3 are positioned by the notches 1a provided in the electronic circuit board 1, the shield case 3 is higher than the electronic circuit board 1 when the shield case 3 is attached by reflow soldering or the like. It can be attached with positional accuracy, and there is no problem due to contact with the electronic component 2 due to the displacement of the position of the shield case 3.
[0017]
As a result, the mounting position of the shield case 3 with respect to the electronic circuit board 1 can be controlled, so that the distance between the shield case 3 and the electronic component 2 can be reduced, and the size of the module itself can be reduced. Can be reduced.
[0018]
The shield case 3 can be soldered to the electronic circuit board 1 as surface mounting, and a separate soldering process is performed to attach the shield case 3 by reflow soldering the shield case 3 simultaneously with the electronic component 2. There is no need to provide it, and it can be implemented by an inexpensive process.
[0019]
Moreover, it becomes possible to suppress the thermal stress of the electronic component 2 by one reflow, and it becomes possible to improve the reliability or to use the inexpensive electronic component 2.
[0020]
Further, the notch 1a of the electronic circuit board 1 is not subjected to through-hole plating, but may be a normal outer shape process. Therefore, the outer shape process of the electronic circuit board 1 is facilitated, and the inexpensive electronic circuit board 1 is provided. It is available.
[0021]
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
3 and 4 are diagrams showing the first embodiment, in which FIG. 3A is a perspective view showing a module assembling process, FIG. 3B is a perspective view showing a completed form of the module, and FIG. It is a BB sectional view.
In the figure, 2a is a tall electronic component, and 3b is an opening of a shield case 3 provided at the position of the tall electronic component 2a. The height of the shield case 3 is set to be the same height as the tall electronic component 2a after being mounted on the electronic circuit board 1.
[0022]
In general, it is known that the shielding effect is maintained even if there is a gap of 1/100 wavelength. In the present embodiment, in consideration of component external dimension tolerance and positional deviation at the time of mounting, a gap capable of maintaining a shielding effect is provided between the tall electronic component 2a and the opening 3b of the shield case 3. The module height can be kept low.
[0023]
For example, the height of the tall electronic component 2a is 1.2 mm, the outer shape is 5 ± 0.1 mm, the mounting position accuracy on the electronic circuit board 1 is ± 0.1 mm, and the thickness of the electronic circuit board 1 is 0.6 mm. Assuming that the processing accuracy of the shield case 3 is ± 0.1 mm, if this embodiment is used, the thickness of the electronic circuit board 2 and the height of 1.2 mm of the tall electronic component 2a are added to 1.8 mm. It becomes possible to suppress the height.
[0024]
In this case, the size of the opening 3b of the shield case 3 is set to 5.3 mm, which is 5.1 mm which is the maximum outer dimension of the tall electronic component 2a and 0.2 mm which is the mounting position deviation range. Set to 5.3 mm + 0.2 / −0 mm.
[0025]
The maximum gap between the tall electronic component 2a and the opening 3b of the shield case 3 is 4.9 mm, which is the minimum for the tall electronic component 2a, and 5.5 mm, which is the maximum size for the opening 3b of the shield case 3. Is a maximum of 0.1 mm, and the gap at this time is the gap when there is no mounting position deviation (5.5-4.9) /2=0.3 mm plus a maximum mounting deviation of 0.1 mm 0.4 mm.
[0026]
Since the maximum gap is 0.4 mm, the shielding effect can shield more than 100 times the wavelength.
Shield frequency = constant (speed of light) / (wavelength x100)
= 3x108 / (0.4x10-3x100)
= 7.5 × 10 9 hertz = 7.5 gigahertz, and it is possible to shield a frequency of 7.5 gigahertz or less.
[0027]
Reference Example 2
Reference Example 2 of the present invention will be described below with reference to the drawings.
FIG. 5 is a diagram showing Reference Example 2 , and is a cross-sectional view of a module component.
In the figure, reference numeral 4 denotes a solder wall constituting a conductive wall, and 1c denotes a pad provided between circuit blocks of the electronic circuit board 1, which are provided between circuit blocks to be shielded.
[0028]
When supplying cream solder or the like for joining the electronic component 2 to the electronic circuit board 1, an electronic circuit board is supplied after printing or dispensing a conductive material such as cream solder on the pads 1 c provided between the circuit blocks. The solder wall 4 is formed by performing reflow soldering together with the electronic component 2 mounted on 1.
[0029]
At this time, the shielding effect is obtained by setting the gap between the solder wall 4 and the shielding case 3 to be 1/100 wavelength or less at which the shielding effect is obtained.
[0030]
According to this reference example, when it is desired to obtain a shield for each circuit block in one module, it is possible to obtain a shielding effect without mounting a plurality of shield cases 3, thereby reducing the component cost and reducing the size of the module. It is possible to reduce man-hours by simplifying manufacturing and manufacturing methods.
[0031]
Reference Example 3
Reference Example 3 of the present invention will be described below with reference to the drawings.
FIG. 6 is a view showing Reference Example 3 , and is a cross-sectional view of a module component.
In Reference Example 3 , a conductive material such as cream solder was supplied to form the conductive wall with the solder wall 4. However, when the interval between the conductive wall and the shield case 3 needs to be narrowed, such as when the shielding frequency is high. As shown in FIG. 6, after a conductive material such as cream solder is supplied by printing or dispensing, a solder ball 4a is mounted as the conductive material and reflowed together with the electronic component 2 mounted on the electronic circuit board 1. The conductive wall may be formed by soldering. The conductive material may be any metal ball, metal block, or the like.
[0032]
In this case, even if the shieldable frequency is high, the gap between the conductive wall and the shield case 3 can be reduced to 1/100 wavelength or less at which a shielding effect can be obtained.
[0033]
Reference Example 4
Reference Example 4 of the present invention will be described below with reference to the drawings.
FIG. 7 is a view showing Reference Example 4 and is a cross-sectional view of a module component.
In the reference example 4 , the solder ball 4a is mounted on the electronic circuit board 1, but a conductive wall made of a conductive material may be provided between the electronic circuit board 1 and the shield case 3 as shown in FIG. Good.
[0034]
An example of the manufacturing method in this case is shown. After a bonding material such as cream solder is supplied to the electronic circuit board 1 by printing or dispensing, the electronic component 2 or the solder ball 4a is mounted. At this time, the height of the solder ball 4a is in contact with the shield case 3 or is lowered by the thickness of the bonding material. Subsequently, a shield case 3 to which a joining material such as flux or cream solder is supplied in advance is mounted, and by reflow soldering, a shield wall by a solder ball 4a can be provided between the electronic circuit board 1 and the shield case 3, and the circuit It becomes possible to shield between blocks.
[0035]
Also in this reference example , the same effect as in the reference example 4 can be obtained.
[0036]
Reference Example 5
8 to 10 are views showing Reference Example 5. FIG. 8A is a perspective view showing a module assembling process, FIG. 8B is a perspective view showing a completed form of the module, and FIG. -C sectional view, FIG. 10 is a perspective view showing a modification of the completed form of the module.
In the figure, 3c shows a state in which a part of the shield case 3 is bent to the electronic component 2 side, and its width is a width of 1/100 wavelength or less to be shielded.
Further, the gap between the bent portion 3c and the electronic circuit board 1 has a width of 1/100 wavelength or less to be shielded.
[0037]
After mounting the electronic component 2 on the electronic circuit board 1, the shield case 3 is attached, and the shield case 3 together with the electronic component 2 is soldered to the shield case soldering pad 1 b on the electronic circuit board 1.
Note that the bending of the shield case 3 may be divided into a plurality as shown in FIG.
[0038]
This structure makes it possible to obtain a shielding effect between circuit blocks and the outside of the module.
[0039]
According to this reference example, when it is desired to obtain a shield for each circuit block in one module, it is possible to obtain a shielding effect without mounting a plurality of shielding cases 3, reducing component costs, and reducing module costs. It is possible to reduce man-hours by downsizing and simplifying the manufacturing method.
[0040]
【The invention's effect】
The shield device according to the present invention has an electronic circuit board on which an electronic component is mounted on one surface, a facing surface facing the one surface, and an opening at a position corresponding to the electronic component on the facing surface. A shield case soldered to the electronic circuit board, wherein the distance from the one surface of the electronic circuit board to the opposing surface of the shield case is the electron relative to the one surface of the electronic circuit board The wall surface surrounding the opening of the shield case and the surface of the electronic component disposed at a position corresponding to the opening are opposed to each other, and the distance from the surface to the wall surface is less than the height of the component Since the distance is such that the shield effect can be maintained, the height of the shield device can be kept low while maintaining the shield effect .
[Brief description of the drawings]
FIG. 1 is a perspective view of a module part using a shield device, showing a reference example 1, FIG. 1 (a) is a perspective view showing a module assembling process, and FIG. 1 (b) is a completed form of the module; FIG.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3 is a diagram showing the first embodiment, and is an external view of a module component using a shield device. FIG. 3 (a) is a perspective view showing an assembly process of the module, and FIG. 3 (b) is a completed module. It is a perspective view which shows a form.
4 is a cross-sectional view taken along line BB in FIG. 3 (b).
FIG. 5 is a diagram showing a reference example 2 , and is a cross-sectional view of a module component using a shield device.
FIG. 6 is a diagram showing Reference Example 3 , and is a cross-sectional view of a module component using a shield device.
FIG. 7 is a diagram showing a reference example 4 , and is a cross-sectional view of a module component using a shield device.
FIGS. 8A and 8B are diagrams showing an external view of a module component using a shield device according to Reference Example 5 ; FIG. 8A is a perspective view showing a module assembling process, and FIG. FIG.
9 is a cross-sectional view taken along the line CC of FIG. 8 (b).
FIG. 10 is a diagram showing a reference example 5, and is a perspective view showing a modified example of the completed form of the module.
11A and 11B are external views of a module component using a conventional shield device. FIG. 11A is a perspective view showing an assembling process of the module, and FIG. 11B is a perspective view showing a completed form of the module. .
FIG. 12 is a cross-sectional view taken along the line DD of FIG.
13A and 13B are external views of module parts using another conventional shield device, in which FIG. 13A is a perspective view showing an assembly process of the module, and FIG. 13B is a perspective view showing a completed form of the module; It is.
14 is a cross-sectional view taken along line EE in FIG. 13 (b).
FIG. 15 is an external view of a module component using still another conventional shield device, and is a perspective view showing a completed form of the module.
16 is a cross-sectional view taken along line FF in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electronic circuit board, 1a Notch, 1b Shield case soldering pad, 1c Pad provided between circuit blocks, 1e Module external electrode, 2 Electronic component, 2a Tall electronic component, 3 Shield case, 3a Positioning protrusion, 3b opening, 3c bent portion, 4 solder wall, 4a solder ball.

Claims (4)

An electronic circuit board with electronic components mounted on one side,
A shield case soldered to the electronic circuit board, having an opposing surface facing the one surface, an opening provided at a position corresponding to the electronic component on the opposing surface,
The distance from the one surface of the electronic circuit board to the opposing surface of the shield case is not more than the height of the electronic component relative to the one surface of the electronic circuit board,
The wall surface surrounding the opening of the shield case and the surface of the electronic component arranged at a position corresponding to the opening are opposed to each other, and the distance from the surface to the wall surface can maintain the shielding effect. A shield device characterized by a distance . The dimension of the distance from the surface of the electronic component to the wall surface is
The shielding apparatus according to claim 1 , wherein the shielding apparatus has a wavelength of 1/100 or less of an electromagnetic wave that requires shielding. In the opening of the shield case,
2. The shield device according to claim 1, wherein a part of the electronic component is inserted. The height of the electronic component with respect to the electronic circuit board, shield apparatus according to claim 1, wherein the the height of the shield case is aligned with respect to the electronic circuit board.

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