Electronic apparatus

Abstract

To provide an electronic apparatus that can realize weight reduction and noise suppression.SOLUTION: An electronic apparatus 10 includes a housing 11, a board 12 arranged inside the housing 11 and carrying a plurality of circuit elements, and a shielding case 15 arranged on the board 12 and made of metal, and a circuit element, from among the plurality of circuit elements, which requires electromagnetic shielding is arranged in an area on the board 12 where the shielding case 15 is arranged. For example, the electronic apparatus 10 further includes a plurality of shielding clips 16 that electrically connect the shielding case 15 to a ground pattern of the board 12, and the intervals between the shielding clips 16 may be set on the basis of the propagation characteristics of noise in a vacuum.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to electronic devices. [Background technology]

[0002] Patent Document 1 discloses a technique for attaching a shield case to a circuit board built into an electronic device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-159144 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides an electronic device that can achieve weight reduction and noise suppression. [Means for solving the problem]

[0005] An electronic device according to one aspect of the present disclosure comprises a housing, a board disposed within the housing and carrying a plurality of circuit elements, and a shielding case provided on the board and made of metal, wherein circuit elements among the plurality of circuit elements that require electromagnetic shielding are disposed in an area on the board where the shielding case is provided. Effect of the Invention

[0006] The present disclosure can provide an electronic device that can achieve weight reduction and noise suppression. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view illustrating a configuration example of an electronic device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing a configuration example of a shield case according to an embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of a wiring pattern that does not use a meander pattern according to the embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a wiring pattern that does not use a meander pattern according to the embodiment. [Diagram 5] FIG. 5 is a diagram showing an example of a wiring pattern using a meander pattern according to the embodiment. [Figure 6] FIG. 6 is a diagram showing an example of a wiring pattern using a meander pattern according to the embodiment. [Figure 7] FIG. 7 is a diagram showing a configuration example of a microstrip line on a surface layer according to an embodiment. [Figure 8] FIG. 8 is a diagram illustrating a configuration example of an inner layer strip line according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component arrangement and connection forms, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0009] In addition, each drawing is a schematic diagram and is not necessarily a precise illustration. In each drawing, the same reference numerals are used for substantially the same configurations, and duplicated explanations may be omitted or simplified.

[0010] (Embodiment) [Knowledge that formed the basis of the invention] In in-vehicle devices, the shift to EVs (Electric Vehicles) has led to the advancement of digitalization of electronic devices, resulting in increased noise interference between devices. In addition, as the number of devices installed in vehicles increases, there is a demand for in-vehicle devices to be lighter. One possible method for achieving weight reduction is to use a plastic case instead of a metal case. However, there are concerns that using a plastic case may reduce noise resistance. For these reasons, EMC (Electromagnetic Compatibility) measures for in-vehicle devices have become an issue.

[0011] In this embodiment, instead of surrounding the entire board with a metal case, devices that require noise countermeasures are arranged in a specific area and a shielding case is used to surround the specific area. In this way, by implementing partial shielding, it is possible to suppress noise while reducing weight. Furthermore, even when a partial shielding structure is used, it is possible to meet EMI (Electromagnetic Interference) standards.

[0012] Furthermore, when using a shielding case, the spacing and impedance of the joints that join the shielding case to the ground plane of the board are important in order to enhance the effect. A common method is to provide multiple joints at intervals of 1 / 20th the wavelength of the noise frequency or less. Alternatively, it is possible to connect the entire periphery of the shielding case to the ground plane of the board. When connecting the entire periphery, the impedance can be reduced, but it becomes impossible to form a wiring pattern on the surface at the joints. This makes it difficult to pull out the wiring from inside the shielding case to the outside. Thus, when connecting the entire periphery, there is an issue that restrictions are imposed on the wiring pattern.

[0013] In this embodiment, the distance between the joints is appropriately set within a range that allows for realization of the noise reduction effect, thereby reducing the restrictions on the wiring pattern while suppressing noise.

[0014] In addition, the external size of the board is determined by the product size that can be placed inside the vehicle. In addition, due to the constraints on the external shape of the board, the distance between each component (i.e., the wiring pattern length) cannot be freely determined in the layout of the components. This causes a problem that the wiring length of the wiring in the board matches the specific wiring length corresponding to a specific frequency band (hereinafter also referred to as the specific band) such as the BDS (Beidou Navigation Satellite System) band and the GLONASS (Global Navigation Satellite System) band, which have the strictest EMC standard limit values, and the noise level in the specific band becomes high. Here, the specific wiring length is the wiring length that becomes an antenna pattern for the specific band.

[0015] In contrast, in this embodiment, the wiring length of all the wiring in the board is intentionally made long so as not to reach the specific wiring length. This makes it possible to prevent the wiring from becoming an antenna pattern for a specific band. Therefore, for example, even when a resin case is used, the EMI standard can be met.

[0016] Furthermore, in this embodiment, in addition to controlling the wiring length, the actual effective relative dielectric constant is calculated from the relative dielectric constant based on the board material. Also, the propagation delay characteristics of the high-speed transmission path of digital signals in the surface layer wiring and inner layer wiring are taken into account. As a result, the wiring length of each layer in the board can be precisely controlled.

[0017] [Electronic device configuration] First, a configuration example of an electronic device 10 according to the present embodiment will be described. Fig. 1 is a perspective view of the electronic device 10 according to the present embodiment. Fig. 1 shows the electronic device 10 in an exploded state.

[0018] The electronic device 10 includes a housing 11, a substrate 12, and a shield case 15. The housing 11 is made of, for example, resin, and includes an upper chassis 13 and a lower chassis 14.

[0019] Substrate 12 is a wiring board and has multiple wiring layers. The wiring layers include a surface layer and one or more inner layers. The number of wiring layers is not particularly limited, but substrate 12 is, for example, a four-layer substrate or a six-layer substrate. Substrate 12 is disposed inside housing 11.

[0020] In addition, a plurality of elements (electronic components) such as integrated circuits are disposed on the substrate 12. Note that only some of these are shown in Fig. 1, with the rest being omitted.

[0021] The electronic device 10 is, for example, an in-vehicle ECU (Electronic Control Unit). The ECU includes, for example, at least one of an ASC (Active Sound Control) unit and an ANC (Active Noise Control) unit that perform in-vehicle sound-related processing. In other words, the ECU has at least one of the functions of ASC and ANC. The ASC performs processing to add engine sound and the like in an EV or hybrid vehicle. The ANC performs processing to cancel noise inside the vehicle.

[0022] For example, the electronic device 10 includes a power supply circuit such as a DC-DC converter, a processor such as a microcomputer or a DSP (digital signal processor), a memory such as a flash memory, and a communication circuit.

[0023] It should be noted that the electronic device 10 is not limited to the above example, and may be an electronic device for in-vehicle use other than the above, or may be an electronic device for use other than in-vehicle use.

[0024] [Shield case configuration] 2 is a perspective view showing the configuration of shield case 15. Shield case 15 is disposed so as to surround a specific region of substrate 12. Shield case 15 is made of metal, for example, SPCC (Steel Plate Cold Commercial).

[0025] Of the multiple circuit elements mounted on substrate 12, those requiring electromagnetic shielding are placed in a specific area surrounded by shield case 15. The other circuit elements are placed outside the specific area and are not surrounded by shield case 15. For example, circuit elements requiring electromagnetic shielding include a power supply circuit and an overload protection circuit. Circuit elements placed outside the specific area (outside shield case 15) include a communication circuit.

[0026] 2, a plurality of shield clips 16 are used as a method for connecting shield case 15 and substrate 12. The plurality of shield clips 16 are surface-mounted on substrate 12. By sandwiching shield case 15 between the plurality of shield clips 16, shield case 15 is fixed to substrate 12 and is electrically connected to the ground plane of substrate 12.

[0027] [Wire length adjustment] In this embodiment, the wiring length of all the wiring on the substrate 12 is made long so as not to become a specific wiring length corresponding to a specific band. This makes it possible to prevent the wiring from becoming an antenna pattern in a specific band. In other words, the substrate 12 does not include wiring with a specific wiring length corresponding to a specific band. In other words, the wiring length of all the wiring on the substrate 12 is not the specific wiring length.

[0028] Specifically, a meander pattern (also called a meander type pattern) is used as a method for adjusting the wiring length of the substrate 12. A meander pattern is a wiring pattern in which the wiring length is longer by meandering the wiring, rather than a wiring pattern in which the wiring length is the shortest.

[0029] 3 and 4 are diagrams for comparison, showing examples of wiring patterns that do not use meander patterns, respectively showing wiring 21 and wiring 22 that do not use meander patterns.

[0030] Figures 5 and 6 correspond to Figures 3 and 4, respectively, and are diagrams showing examples of wiring patterns using meander patterns. Wiring 31 shown in Figure 5 includes a meander pattern 33. Wiring 32 shown in Figure 6 includes a meander pattern .

[0031] Here, the meander pattern is generally used for the purpose of matching communication timing by aligning the wiring lengths of multiple wirings, for example, by matching the delay times of signals in multiple wirings such as data lines and clock lines, i.e., for matching propagation delay characteristics. In other words, the meander pattern is used to achieve equal-length wiring for each signal line that must be synchronized. On the other hand, in this embodiment, this meander pattern is used to prevent the wiring length from becoming a specific wiring length.

[0032] [Calculating specific wiring length] Next, a method for calculating the specific wiring length will be described. First, the propagation speed of a wiring in a vacuum will be described. The propagation speed in a vacuum is 300,000 km / sec, which is the same as the speed of light c. Specifically, the propagation speed in a vacuum is defined by the following (Equation 1).

[0033] c=1 / √(ε0×μ0) (Equation 1)

[0034] Here, ε0 is the dielectric constant of a vacuum, ε0=8.85×10 -12 μ0 is the magnetic permeability of a vacuum, μ0=4π×10 -7 Therefore, the propagation speed c = 2.99792458 × 10 8 [m / sec].

[0035] On the other hand, in the case of coaxial cables, the propagation speed decreases mainly due to the influence of the relative dielectric constant εr of the material. This decrease in propagation speed is called wavelength shortening. In this case, the wavelength is expressed by the following (Equation 2).

[0036] λ=λ0×1 / √εr (Formula 2)

[0037] Here, λ0 is the wavelength in a vacuum. For example, if the insulator is polyethylene, εr = 2.2 to 2.4, and the propagation velocity is 2.99792458 / √2.3 = 1.97677293 × 10 8 [m / sec]. In other words, the propagation speed in a coaxial cable is about 66% of that in a vacuum. Therefore, the wavelength shortening factor is 0.66.

[0038] As with the coaxial cable, the propagation speed of a signal in the wiring formed on the board can be calculated.

[0039] Here, this propagation velocity is generally calculated to be about half the speed of light c. If the board material is glass epoxy (FR-4), its relative dielectric constant is 4.3 / 1GHz. Therefore, the propagation velocity is 2.99792458 / √4.3=1.4457276101×10 8 [m / sec].

[0040] However, the propagation velocity obtained by this calculation has an error with respect to the actual propagation velocity, and since the error is particularly large in the GHz band, more strict control is required.

[0041] Here, a microstrip line is used on the surface layer of the substrate, and a strip line is used on the inner layer of the substrate. In this embodiment, different calculations are performed on the surface layer and the inner layer, so that the different propagation velocities on the surface layer and the inner layer are precisely calculated.

[0042] Fig. 7 is a diagram showing a configuration example of a microstrip line on the surface layer. As shown in Fig. 7, on the surface layer, the substrate 12 includes a ground conductor 41, an insulating layer 42, and a wiring 43. The ground conductor 41 is an electrically grounded conductor, for example, a metal layer. The insulating layer 42 is an insulator layer disposed between the ground conductor 41 and the wiring 43, and is also called an insulator prepreg. The wiring 43 is a metal wiring pattern and transmits a signal.

[0043] In this embodiment, the effective relative dielectric constant εe is calculated from the relative dielectric constant εr of the insulating layer 42, the thickness (height) h of the insulating layer 42, and the width w of the wiring 43 according to the following (Equation 3).

[0044] εe=((εr+1) / 2)+((εr-1) / 2)×1 / (√(1+(10×h) / w) ··· (Formula 3)

[0045] In addition, the propagation velocity v is calculated from the speed of light c and the effective relative dielectric constant εe of the insulating layer 42 according to the following (Equation 4).

[0046] v=c / √εe ··· (Equation 4)

[0047] Furthermore, the wavelength λ is calculated from the frequency f and propagation speed v of a specific band using the following (Equation 5).

[0048] λ=v / f (Equation 5)

[0049] Fig. 8 is a diagram showing a configuration example of a stripline in an inner layer. As shown in Fig. 8, in the inner layer, the substrate 12 includes ground conductors 51 and 54, an insulating layer 52, and a wiring 53. The ground conductors 51 and 54 are electrically grounded conductors, for example, metal layers. The insulating layer 52 is an insulator layer disposed between the ground conductor 51 and the ground conductor 54. The wiring 53 is a metal wiring pattern disposed in the insulating layer 52, and transmits a signal.

[0050] In this case, the propagation velocity v is calculated from the speed of light c and the relative dielectric constant εr of the insulating layer 42 according to the following (Equation 6).

[0051] v=c / √εr ··· (Equation 6)

[0052] In addition, the wavelength λ is calculated from the propagation velocity v obtained by (Equation 6) using the above (Equation 5). In this way, different propagation velocities v are calculated for the surface layer and the inner layer, and different wavelengths λ are calculated.

[0053] Next, the specific wiring length of the surface layer is calculated based on the wavelength λ of the surface layer, and the specific wiring length of the inner layer is calculated based on the wavelength λ of the inner layer. For example, the specific wiring length is λ / 4.

[0054] Next, all wiring patterns of the surface layer and the inner layer are created so that the wiring length of the wiring of the surface layer is not equal to the calculated specific wiring length of the surface layer, and the wiring length of the wiring of the inner layer is not equal to the calculated specific wiring length of the inner layer. For example, the wiring patterns are created based on a predetermined rule (for example, so that the wiring length is the shortest). Next, from the created wiring patterns, wiring having a wiring length that matches the calculated specific wiring length is extracted, and the extracted wiring is replaced with a wiring having a different wiring length (for example, a wiring having the above-mentioned meander pattern).

[0055] For example, when εr = 3.9, h = 0.2 mm, and w = 0.1 mm, the propagation velocity v of the surface layer is 1.80481941 × 10 8 [m / sec], and the propagation velocity v of the inner layer is 1.51805812×10 8 [m / sec]. Therefore, the specific wiring length of the surface layer corresponding to the BDS band (1.56 GHz) is about 28.9 mm, and the specific wiring length of the inner layer is about 24.3 mm. In detail, since the BDS band is a band of 1559.052 MHz to 1563.144 MHz, the specific wiring length of the surface layer corresponding to the BDS band is included in 28.8 mm to 29.0 mm, and the specific wiring length of the inner layer is included in 24.2 mm to 24.4 mm.

[0056] In addition, the specific wiring length of the surface layer corresponding to the GLONASS band (1.60 GHz) is about 28.1 mm to 28.2 mm, and the specific wiring length of the inner layer is about 23.7 mm to 23.8 mm. In detail, since the GLONASS band is a band of 1594.0625 MHz to 1609.375 MHz, the specific wiring length of the surface layer is included in 28.0 mm to 28.4 mm, and the specific wiring length of the inner layer is included in 23.5 mm to 23.9 mm.

[0057] In the above, the specific wiring length is λ / 4, but the specific wiring length may be λ / 2. In that case, the specific wiring length of the surface layer corresponding to the GLONASS band (1.60 GHz) is about 56.2 mm to 56.4 mm, and the specific wiring length of the inner layer is about 47.4 to 47.6 mm. In detail, since the GLONASS band is a band of 1594.0625 MHz to 1609.375 MHz, the specific wiring length of the surface layer is included in 56.0 mm to 56.8 mm, and the specific wiring length of the inner layer is included in 47.0 mm to 47.8 mm. In addition, both λ / 4 and λ / 2 may be used as the specific wiring length.

[0058] When λ / 2 is used, in the above example, the specific wiring length of the surface layer corresponding to the BDS band (1.56 GHz) is about 57.8 mm, and the specific wiring length of the inner layer is about 48.6 mm. For example, the specific wiring length of the surface layer corresponding to the BDS band is included in 57.6 mm to 58.0 mm, and the specific wiring length of the inner layer is included in 48.4 mm to 48.8 mm.

[0059] In addition, the specific wiring length of the surface layer corresponding to the GLONASS band (1.60 GHz) is about 56.3 mm to 56.5 mm, and the specific wiring length of the inner layer is about 47.3 mm to 47.5 mm. For example, the specific wiring length of the surface layer is included in 56.0 mm to 56.8 mm, and the specific wiring length of the inner layer is included in 47.0 mm to 47.8 mm.

[0060] The numerical ranges shown above are merely examples, and if the part number of the board is different, the dielectric constant εr will change due to the different base material, so control of the line length will be necessary. In addition, to ensure a larger margin, the numerical range of the specific line length may be widened. Conversely, to widen the range of usable line lengths, the numerical range of the specific line length may be narrowed.

[0061] In the above, the BDS band and the GLONASS band are given as examples of the specific band, but the specific band may be another frequency band. Furthermore, the specific band is not limited to the GHz band. For example, the specific band may be the operating frequency of a circuit or the like included in the electronic device 10, or the operating frequency of a device connected to the electronic device 10. Furthermore, the specific band may be a frequency that is n times (n is a natural number) these operating frequencies. For example, the specific band may be a frequency that is an odd-numbered multiple of these operating frequencies.

[0062] For example, the specific band may be the frequency of a signal transmitted from a DC-DC converter. For example, when the frequency is 2.10 GHz and λ / 2 is used, the specific wiring length of the surface layer is about 43.0 mm, and the specific wiring length of the inner layer is about 36.1 mm.

[0063] In addition, there may be a plurality of specific bands. In this case, the unused wiring length is determined for each specific band, and the wiring pattern is generated so as not to include any of the wiring lengths determined.

[0064] [Adjusting the spacing of the shield clips] The noise suppression effect of shielding case 15 depends on the spacing of shielding clips 16. Specifically, in areas where shielding clips 16 are not placed, a gap of about several millimeters occurs between shielding case 15 and board 12. Noise propagates through this gap.

[0065] Furthermore, while the noise suppression effect can be improved by narrowing the spacing between shield clips 16, increasing the number of shield clips 16 placed increases the restrictions on the wiring pattern to be placed on the surface. In this embodiment, the spacing between shield clips 16 is appropriately set within a range that achieves the noise suppression effect, thereby reducing the restrictions on the wiring pattern while suppressing noise.

[0066] Specifically, the wavelength λ is calculated from the frequency f of the specific band and the propagation speed v in a vacuum using the above (Equation 5). Next, the specific interval of the shield clip 16 is calculated based on the wavelength λ. For example, the specific interval is λ / 2. The specific interval may be λ / 4.

[0067] Next, the spacing between the shield clips 16 is determined so that the spacing is not the specific spacing. For example, the spacing between the shield clips 16 is determined so that the spacing is narrower than the specific spacing.

[0068] For example, the specific interval corresponding to the BDS band (1.56 GHz) is 96.1 mm, the specific interval corresponding to the GLONASS band (1.60 GHz) is 93.7 mm, and the specific interval corresponding to the frequency of the signal transmitted from the DC-DC converter (2.10 GHz) is 71.4 mm.

[0069] In addition, by widening the spacing between shield clips 16, the constraints on the surface wiring can be further alleviated. Therefore, for example, by making the spacing between shield clips 16 wider than 1 / 20 of the wavelength of a commonly used noise frequency (for example, 9.4 mm for 1.6 GHz), the constraints on the surface wiring can be reduced more than when a spacing of 1 / 20 of the wavelength or less is used. In other words, the spacing between shield clips 16 may be narrower than the specific spacing and wider than 1 / 20 of the wavelength.

[0070] Although there are multiple intervals between adjacent shield clips 16, not all of the intervals need to be the same. In this case, all of the multiple intervals are narrower than the specific interval. On the other hand, not all of the intervals need to be wider than 1 / 20 of the wavelength, and at least one interval may be wider than 1 / 20 of the wavelength. Even in this case, the constraints on the surface wiring can be reduced compared to when intervals of 1 / 20 of the wavelength or less are used.

[0071] [Effects, etc.] Inventions derived from the disclosure of this specification are, for example, the following inventions. Hereinafter, the inventions derived from the disclosure of this specification will be described together with the effects and the like obtained by the inventions.

[0072] For example, electronic device 10 according to one embodiment of the present disclosure comprises housing 11, substrate 12 disposed within housing 11 and carrying a plurality of circuit elements, and shielding case 15 provided on substrate 12 and made of metal, and among the plurality of circuit elements, those circuit elements requiring electromagnetic shielding are disposed in the area of ​​substrate 12 where shielding case 15 is provided.

[0073] This allows weight reduction compared to when the entire board is enclosed in a metal case. Also, noise suppression can be achieved for necessary circuit elements. Therefore, weight reduction and noise suppression can be achieved.

[0074] For example, the electronic device 10 may further include a plurality of shield clips 16 that electrically connect the shield case 15 to the ground pattern of the substrate 12, and the intervals between the shield clips 16 may be set based on the propagation characteristics of noise in a vacuum. For example, the propagation characteristics are the propagation speed or the wavelength.

[0075] This allows the spacing of the shield clips 16 to be set taking into account the spacing that has the effect of suppressing noise in a specific band. Therefore, by widening the spacing while preventing a reduction in the noise suppression effect, the constraints on the wiring on the surface layer can be reduced.

[0076] For example, the spacing between the shield clips may be less than a specific spacing based on the propagation characteristics of noise in a vacuum, and may be greater than 1 / 20 of the wavelength of the noise.

[0077] This makes it possible to suppress a decrease in the effect of suppressing noise, while reducing the constraints on the surface wiring compared to the case where an interval of 1 / 20 or less of the wavelength is used.

[0078] For example, the specific interval may be determined based on a wavelength λ, which is determined based on λ=v / f, where f is the frequency of the noise and v is the propagation speed in a vacuum, and the specific interval may be λ / 2 or λ / 4.

[0079] This makes it possible to appropriately reduce the constraints on the surface wiring while suppressing the reduction in the noise suppression effect.

[0080] For example, when the noise frequency is 2.10 GHz, the specific interval may be 71.4 mm, when the noise frequency is 1.60 GHz, the specific interval may be 93.7 mm, and when the noise frequency is 1.56 GHz, the specific interval may be 96.1 mm.

[0081] This makes it possible to appropriately reduce the constraints on the surface wiring while suppressing the reduction in the noise suppression effect.

[0082] For example, the circuit elements requiring electromagnetic shielding may include a power supply circuit and an overload protection circuit, thereby making it possible to suppress noise in the circuit elements requiring electromagnetic shielding.

[0083] For example, the housing may be made of resin, which can reduce the weight of the electronic device 10.

[0084] For example, the substrate 12 has multiple wiring layers, at least some of the wirings 31 (or wirings 32) formed in the multiple wiring layers have meander patterns 33 (or meander patterns 34), and the meander patterns of the wirings formed in different wiring layers are set based on different parameters. Here, the parameters are, for example, the propagation speed v, the wavelength λ, or the wiring length corresponding to a specific band.

[0085] According to this, the meander pattern can be formed for each wiring layer using parameters suitable for that wiring layer, and therefore, for example, noise corresponding to a specific band can be suppressed.

[0086] For example, a meandering pattern may be used so that the length of the wiring does not become a specific wiring length corresponding to a specific frequency band. Here, the specific wiring length is, for example, a wiring length that becomes an antenna pattern for a specific frequency band (specific band).

[0087] According to this, the wiring can be prevented from becoming a specific wiring length corresponding to a specific band, so that noise corresponding to the specific band can be suppressed.

[0088] For example, different specific wiring lengths may be set for different wiring layers. In this way, for each wiring layer, the length of the wiring corresponding to the specific band can be calculated using parameters suitable for that wiring layer. Therefore, noise corresponding to the specific band can be suppressed. For example, the different wiring layers may be a surface layer and an inner layer.

[0089] For example, the specific wiring length may be set based on a specific frequency band, a wiring width, and a thickness of the insulating prepreg. For example, the specific wiring length is calculated using the above (Equation 3) to (Equation 5). This allows the specific wiring length to be calculated with high accuracy by taking into account multiple parameters.

[0090] For example, the electronic device 10 may be an in-vehicle electronic device. For example, the electronic device 10 may be an ECU (Electronic Control Unit) including at least one of an ASC (Active Sound Control) unit and an ANC (Active Noise Control) unit.

[0091] For example, the substrate 12 according to one embodiment of the present disclosure is a substrate 12 having a plurality of wiring layers, in which at least a portion of the wiring 31 (or wiring 32) formed in the plurality of wiring layers has a meander pattern 33 (or meander pattern 34), and the meander patterns of the wiring formed in different wiring layers are set based on different parameters. Here, the substrate 12 is an example of a wiring substrate. Here, the parameters are, for example, a propagation speed v, a wavelength λ, or a wiring length corresponding to a specific band.

[0092] According to this, the meander pattern can be formed for each wiring layer using parameters suitable for that wiring layer, and therefore, for example, noise corresponding to a specific band can be suppressed.

[0093] (Other embodiments) Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments.

[0094] For example, the electronic device according to the above embodiment may be mounted on a moving body device other than a vehicle. The moving body device may be, for example, an aircraft or a ship. Furthermore, the present disclosure may be realized as such a moving body device other than a vehicle.

[0095] In addition, the general or specific aspects of the present disclosure may be realized in a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or in any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a computer-readable non-transitory recording medium.

[0096] In addition, the present disclosure also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art may conceive, or forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the spirit of the present disclosure. [Industrial Applicability]

[0097] The electronic device of the present disclosure is useful, for example, as an in-vehicle electronic device. [Explanation of symbols]

[0098] 10 Electronic equipment 11. Cabinet 12 Substrate 13 Upper chassis 14 Lower Chassis 15 Shielding case 16 Shield Clip 21, 22, 31, 32 Wiring 33, 34 Meander pattern 41, 51, 54 Ground conductor 42, 52 Insulation layer 43, 53 Wiring

Claims

1. A housing and A substrate disposed within the housing and having a plurality of circuit elements mounted thereon; a shield case provided on the substrate and made of metal; Among the plurality of circuit elements, circuit elements that require electromagnetic shielding are disposed in an area on the substrate where the shield case is provided. electronic equipment.

2. The electronic device further comprises: a plurality of shield clips for electrically connecting the shield case to a ground pattern of the circuit board; The spacing between the shield clips is set based on the noise propagation characteristics in a vacuum.

2. The electronic device according to claim 1.

3. The interval between the shield clips is smaller than a specific interval based on the propagation characteristics of the noise in a vacuum, and is larger than 1 / 20 of the wavelength of the noise.

3. The electronic device according to claim 2.

4. The specific interval is determined based on a wavelength λ, which is determined based on λ=v / f, where f is the frequency of the noise and v is the propagation speed in a vacuum; The specific interval is λ / 2 or λ / 4.

4. The electronic device according to claim 3.

5. When the frequency of the noise is 2.10 GHz, the specific interval is 71.4 mm; When the frequency of the noise is 1.60 GHz, the specific interval is 93.7 mm; When the noise frequency is 1.56 GHz, the specific interval is 96.1 mm.

4. The electronic device according to claim 3.

6. The circuit elements that require electromagnetic shielding include a power supply circuit and an overload protection circuit. The electronic device according to any one of claims 1 to 5.

7. The housing is made of resin. The electronic device according to any one of claims 1 to 5.

8. The substrate has a plurality of wiring layers, At least some of the wirings formed in the plurality of wiring layers have a meander pattern, The meandering patterns of the wirings formed in different wiring layers are set based on different parameters. The electronic device according to any one of claims 1 to 5.

9. The meander pattern is used so that the length of the wiring does not become a specific wiring length corresponding to a specific frequency band.

9. The electronic device according to claim 8.

10. Different specific wiring lengths are set for different wiring layers.

10. The electronic device according to claim 9.

11. The specific wiring length is set based on the specific frequency band, the wiring width, and the thickness of the insulating prepreg.

10. The electronic device according to claim 9.

12. The electronic device is for vehicle use. The electronic device according to any one of claims 1 to 5.

13. The electronic device is an ECU (Electronic Control Unit) including at least one of an ASC (Active Sound Control) unit and an ANC (Active Noise Control) unit.

13. The electronic device according to claim 12.

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