ELECTRONIC DEVICE

Abstract

An electronic device (10) comprising: a housing (11); a circuit board (12) arranged within the housing (11) on which a plurality of circuit elements are mounted; and a shielding housing (15) provided on the circuit board (12) and made of metal. Among the plurality of circuit elements, a circuit element requiring electromagnetic shielding is located in a region of the circuit board (12) where the shielding housing (15) is provided. For example, the electronic device (10) further comprises a plurality of shielding clips (16) that electrically connect the shielding housing (15) to a ground pattern of the circuit board (12). The intervals of the plurality of shielding clips (16) are configured based on a noise propagation characteristic in a vacuum.

Description

[Technical field]

[0001] The present disclosure relates to an electronic device. [State of the art]

[0002] Patent Literature (PTL) 1 discloses a technique for attaching a shielding housing to a circuit board that is incorporated into an electronic device. [Citation list][Patent literature]

[0003] [PTL 1] Japanese Disclosure Document No. 2005-159144 [Summary of the invention][Technical problem]

[0004] The present disclosure provides an electronic device capable of achieving weight reduction and noise suppression. [Solution to the task]

[0005] An electronic device according to one aspect of the present disclosure comprises: a housing; a circuit board arranged within the housing and on which a plurality of circuit elements are mounted; and a shielding housing provided on the circuit board and made of metal. Among the plurality of circuit elements, a circuit element requiring electromagnetic shielding is placed in an area of ​​the circuit board where the shielding housing is provided. [Advantageous effects of the invention]

[0006] The present disclosure can provide an electronic device capable of achieving weight reduction and noise suppression. [Brief description of the drawings] [ Fig. 1] Fig. Figure 1 is a perspective view that represents an embodiment of an electronic device according to one embodiment. [ Fig. 2] Fig. Figure 2 is a perspective view showing an embodiment of a shielding housing according to one embodiment. [ Fig. 3] Fig. Figure 3 is a diagram showing an example of a wiring pattern that does not use a meandering pattern according to the embodiment. [ Fig. 4] Fig. Figure 4 is a diagram showing an example of a wiring pattern that does not use a meandering pattern according to the embodiment. [ Fig. 5] Fig. Figure 5 is a diagram showing an example of a wiring pattern using the meandering pattern according to the embodiment. [ Fig. 6] Fig. Figure 6 is a diagram showing an example of a wiring pattern using the meandering pattern according to the embodiment. [ Fig. 7] Fig. Figure 7 is a diagram illustrating an embodiment of a microstrip line of a surface layer according to the embodiment. [ Fig. 8] Fig. Figure 8 is a diagram that illustrates an embodiment of a strip line of an inner layer according to the embodiment. [Description of embodiments]

[0007] In the following, embodiments are specifically described with reference to the drawings. Furthermore, each of the embodiments described below illustrates a generic or specific example. The numerical values, shapes, materials, structural elements, the arrangement and connection of the structural elements, steps, the processing sequence of the steps, etc., shown in the following exemplary embodiments are merely examples and are therefore not intended to limit the present disclosure. Furthermore, among the elements in the following embodiments, structural elements not listed in the independent claims are described as optional elements.

[0008] Furthermore, the figures are schematic diagrams and not necessarily precise representations. It should be noted that elements that are essentially the same in each figure are labeled with the same reference symbols, and overlapping descriptions may be omitted or simplified. [Form of implementation][Underlying knowledge base of the invention]

[0009] In vehicle electronics, the increasing digitization of electronic devices due to the shift to electric vehicles (EVs) has led to a rise in noise interference between devices. Furthermore, with the increasing number of devices in vehicles, there is a need for these devices to be lightweight. One method considered for achieving weight reduction is the use of a resin housing instead of a metal one. However, there is concern that using a resin housing will reduce noise immunity. Because of these factors, electromagnetic compatibility (EMC) measures for vehicle electronics have become a critical issue.

[0010] In the present embodiment, instead of enclosing the entire circuit board with a metal housing, devices requiring noise countermeasures are grouped together and placed in a specific area, and a shielding enclosure is used to enclose this specific area. In this way, implementing partial shielding allows for weight reduction while simultaneously achieving noise suppression. Furthermore, even with a partial shielding structure, EMI (electromagnetic interference) standards can be met.

[0011] Furthermore, when using a shielding enclosure, the placement intervals and impedance of the connections linking the enclosure to the board's ground plane are important for improving the enclosure's effectiveness. A common approach involves providing numerous connections at intervals less than or equal to 1 / 20th of the noise frequency wavelength. Alternatively, the entire perimeter of the shielding enclosure can be connected to the board's ground plane. While connecting the entire perimeter reduces impedance, it makes it impossible to establish a surface-level wiring pattern at the connections. This complicates routing from the inside of the shielding enclosure to the outside. Therefore, connecting the entire perimeter introduces limitations to the wiring pattern.

[0012] In the present embodiment, the intervals of these connections are suitably set within a range that can achieve a noise reduction effect, thereby reducing restrictions on the wiring pattern while suppressing noise.

[0013] Furthermore, the external dimensions of the circuit board are also determined by the product size that can be placed within the vehicle cabin. Additionally, due to the constraints on the board's external shape, the spacing between each component (i.e., the length of the wiring pattern) in each component's layout cannot be freely determined. This means that the wiring length on the board must correspond to the specific wiring length associated with a particular frequency band (hereinafter also referred to as the specific band), such as the BeiDou Navigation Satellite System (BDS) band and the Global Navigation Satellite System (GLONASS) band, which have the strictest limits in the EMC standard, leading to a problem of high noise levels within the specific band.Here, the specific wiring length is a wiring length that causes the wiring to function as an antenna pattern for the specific band.

[0014] In contrast, in the present embodiment, the total wiring length of all wiring within the circuit board is intentionally designed to be long enough so that it does not become a specific wiring length. This prevents the wiring from forming an antenna pattern for a specific band. Therefore, for example, the EMI standard can be met even when a resin enclosure is used.

[0015] In addition, the present embodiment not only controls the wiring length, but also calculates the actual effective relative permittivity from a relative permittivity based on the circuit board material. Furthermore, propagation delay characteristics of digital signals in high-speed transmission paths are taken into account in both surface layer and sublayer wiring. This allows the wiring length to be precisely controlled for each layer on the circuit board. [Design of an electronic device]

[0016] First, an embodiment example of an electronic device 10 according to the present embodiment is described. Fig. Figure 1 is a perspective view of an electronic device 10 according to the present embodiment. Fig. Figure 1 shows an electronic device 10 in an exploded view.

[0017] The electronic device 10 comprises a housing 11, a circuit board 12 and a shielding housing 15. The housing 11 is made of resin, for example, and comprises an upper chassis 13 and a lower chassis 14.

[0018] The circuit board 12 is a wiring board and comprises a number of wiring layers. These wiring layers include a surface layer and one or more internal layers. It should be noted that, although the number of wiring layers is not particularly limited, circuit board 12 could, for example, be a 4-layer or a 6-layer board. The circuit board 12 is located within the housing 11.

[0019] Furthermore, a variety of elements (electronic components), such as integrated circuits, are arranged on board 12. It should be noted that only some of these elements are in Fig. 1 are shown, with the rest omitted.

[0020] The electronic device 10 is, for example, an electronic control unit (ECU) for use in a vehicle. The ECU includes, for example, an active sound control unit (ASC) and / or an active noise control unit (ANC) that performs sound-related processing in a vehicle. In other words, the ECU has the function of at least one ASC or ANC. The ASC unit performs processing to add engine noise, etc., in an EV or hybrid vehicle. The ANC unit performs processing to suppress noise within the vehicle.

[0021] 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 digital signal processor (DSP), a memory, such as a flash memory, and a communication circuit.

[0022] It should be noted that the electronic device 10 is not limited to the example above. The electronic device 10 may be a different electronic device for use in a vehicle than the one above, or it may be a different electronic device for use in a vehicle altogether. [Design of a shielding enclosure]

[0023] Fig. Figure 2 is a perspective view showing the design of a shielding enclosure 15. The shielding enclosure 15 is arranged to enclose a specific area of ​​the circuit board 12. The shielding enclosure 15 is made of metal, for example, cold-rolled steel sheet (SPCC).

[0024] Among the numerous circuit elements provided on the circuit board 12, those requiring electromagnetic shielding are located within the specific area enclosed by the shielding housing 15. The remaining circuit elements are located outside this specific area and are not enclosed by the shielding housing 15. For example, circuit elements requiring electromagnetic shielding include the power supply circuit and an overload protection circuit. Furthermore, circuit elements located outside this specific area (i.e., outside the shielding housing 15) include the communication circuit.

[0025] Furthermore, as in Fig. Figure 2 shows a plurality of shielding clips 16 used as a method for connecting the shielding housing 15 and the circuit board 12. The plurality of shielding clips 16 is surface-mounted on the circuit board 12. By sandwiching the shielding housing 15 between the plurality of shielding clips 16, the shielding housing 15 is attached to the circuit board 12 and electrically connected to the ground plane of the circuit board 12. [Adjusting the wiring length]

[0026] In the present embodiment, the total wiring length of the circuit board 12 is designed to be long, so that it does not become a specific wiring length corresponding to a specific band. This prevents the wiring from becoming an antenna pattern in a specific band. In particular, the circuit board 12 does not include any wiring with a specific wiring length corresponding to a specific band. In other words, the total wiring length of the circuit board 12 is not the specific wiring length.

[0027] In particular, a meandering pattern (also called a meandering pattern) is used as a method for adjusting the wiring length of board 12. A meandering pattern is not a wiring pattern where the wiring length is shortest, but rather a wiring pattern where the wiring length is increased by making the wiring meander.

[0028] Fig. 3 and Fig. Figure 4 are diagrams for comparison and represent examples of wiring patterns that do not use meandering patterns. Fig. 3 and Fig. 4 each represent a wiring 21 and a wiring 22 that do not use meandering patterns.

[0029] Fig. 5 and Fig. 6 each correspond Fig. 3 and Fig. Figures 4 and 5 are diagrams that illustrate examples of wiring patterns using meandering designs. Wiring diagram 31, shown in Figure 4, is shown in Figure 5. Fig. Figure 5 shows a meandering pattern 33. The wiring 32, which is in Fig. Figure 6 shows a meandering pattern 34.

[0030] Here, meandering patterns are generally used to standardize the wiring lengths of multiple wires, in order to align the delay times of signals on multiple wires, such as data lines and clock lines, to synchronize communication times, i.e., to ensure consistent propagation delay characteristics. In other words, the meandering pattern is used to implement wiring of the same length for each signal line that needs to be synchronized. In contrast, in the present embodiment, the meandering pattern is used to prevent the wiring length from becoming a specific, fixed length. [Calculation of the specific wiring length]

[0031] Next, a method for calculating the specific wiring length is described. First, the propagation speed of a wire in a vacuum is described. The propagation speed in a vacuum is 300,000 km / s, which is equal to the speed of light c. In particular, the propagation speed in a vacuum is defined by (Equation 1) below. c=1 / √(ε0×μ0)

[0032] Here, ε0 is the dielectric constant of a vacuum and ε0 = 8.85 × 10 -12 µ0 is the magnetic permeability of a vacuum and µ0 = 4π × 10 -7 Therefore, the propagation speed c = 2.99792458 × 10 8 [m / s].

[0033] On the other hand, in the case of coaxial cables, the propagation speed decreases mainly due to the influence of the material's relative permittivity εr. This decrease in propagation speed is called wavelength reduction. The wavelength in this case is represented by (Equation 2) below. λ=λ0×1 / √εr

[0034] Here, λ0 is the wavelength in a vacuum. If, for example, the insulator is polyethylene, εr = 2.2 to 2.4, and the propagation speed is given as 2.99792458 / √2.3 = 1.97677293 × 10⁻⁶ 8 [m / s] calculated. In other words, the propagation speed in a coaxial cable is approximately 66% of that in a vacuum. Therefore, the wavelength reduction rate is 0.66.

[0035] As with coaxial cables, the propagation speed of a signal in a wiring configuration formed on the circuit board can be calculated.

[0036] Here, this propagation speed is generally calculated as approximately half the speed of light, c. If the circuit board material is glass epoxy (FR-4), its relative permittivity is 4.3 / 1 GHz. Therefore, the propagation speed is 2.99792458 / √4.3 = 1.4457276101 × 10⁻⁶ 8 [m / s].

[0037] However, the propagation speed obtained through this calculation contains an error compared to the actual propagation speed. Since there is a particularly large error in the GHz band, stricter control is required.

[0038] Here, microstrip lines are used on the surface layer of the circuit board, and strip lines are used on the inner layer of the circuit board. In the present embodiment, different propagation speeds for the surface layer and the inner layer are precisely calculated by performing separate calculations for the surface layer and the inner layer.

[0039] Fig. Figure 7 is a diagram illustrating an example of a surface layer microstrip line design. As in Fig. As shown in Figure 7, the circuit board 12 comprises a ground conductor 41, an insulating layer 42, and wiring 43 in its surface layer. The ground conductor 41 is an electrically grounded conductor and is, for example, a metal layer. The insulating layer 42 is an insulating layer located between the ground conductor 41 and the wiring 43 and is also referred to as an insulator prepreg. The wiring 43 is a metal wiring pattern and transmits a signal.

[0040] In the present embodiment, the effective relative dielectric constant εe is calculated from (equation 3) below using 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. εe=((εr+1) / 2)+((εr−1) / 2)×1 / (√(1+(10×h) / w)

[0041] Furthermore, the propagation speed v is calculated from (equation 4) below using the speed of light c and the effective relative permittivity εe of the insulating layer 42. v=c / √εe

[0042] Additionally, the wavelength λ is calculated from the frequency f of the specific band and the propagation speed v using (equation 5) below. λ=v / f

[0043] Fig. Figure 8 is a diagram illustrating an example of the design of a strip line in an inner layer. As in Fig.As shown in Figure 8, the circuit board 12 comprises, in its inner layer, ground conductors 51 and 54, an insulating layer 52, and wiring 53. The ground conductors 51 and 54 are electrically grounded conductors and are, for example, metal layers. The insulating layer 52 is an insulating layer located between the ground conductor 51 and the ground conductor 54. The wiring 53 is a metal wiring pattern located within the insulating layer 52 and transmits a signal.

[0044] Furthermore, the propagation speed v is calculated from (equation 6) below using the speed of light c and the relative permittivity εr of the insulating layer 42. v=c / √εr

[0045] Furthermore, the wavelength λ is calculated from the propagation speed v, obtained from (Equation 6), using (Equation 5) above. In this way, different propagation speeds v and different wavelengths λ are calculated for the surface layer and the inner layer.

[0046] Next, the specific wiring length for the surface layer is calculated based on the wavelength λ of the surface layer, and the specific wiring length for the inner layer is calculated based on the wavelength λ of the inner layer. For example, the specific wiring length is λ / 4.

[0047] Next, all wiring patterns for the surface layer and the inner layer are generated such that the wiring length in the surface layer is not the calculated specific wiring length for the surface layer, and so that the wiring length in the inner layer is not the calculated specific wiring length for the inner layer. For example, the wiring patterns are generated based on a predetermined rule (for example, so that the wiring length is shortest). Next, a wiring pattern with a length matching the calculated specific wiring length is extracted from the generated wiring patterns, and the extracted wiring pattern is replaced with a wiring pattern with a different length (for example, a wiring pattern with the meandering pattern described above).

[0048] For example, if εr = 3.9, h = 0.2 mm and w = 0.1 mm, the propagation speed v of the surface layer is 1.80481941 × 10 8 [m / s], and the propagation speed v of the inner layer is 1.51805812 × 10 8 [m / s]. Therefore, the specific wiring length for the surface layer corresponding to the BDS band (1.56 GHz) is approximately 28.9 mm, and the specific wiring length for the inner layer is approximately 24.3 mm. Since the BDS band is a band from 1559.052 MHz to 1563.144 MHz, in particular, the specific wiring length for the surface layer corresponding to the BDS band is contained in the range of 28.8 mm to 29.0 mm, and the specific wiring length for the inner layer is contained in the range of 24.2 mm to 24.4 mm.

[0049] Furthermore, the specific wiring length for the surface layer, corresponding to the GLONASS band (1.60 GHz), is approximately 28.1 mm to 28.2 mm, and the specific wiring length for the inner layer is approximately 23.7 mm to 23.8 mm. Since the GLONASS band is a band from 1594.0625 MHz to 1609.375 MHz, the specific wiring length for the surface layer is specifically within the range of 28.0 mm to 28.4 mm, and the specific wiring length for the inner layer is within the range of 23.5 mm to 23.9 mm.

[0050] It should be noted that, although an example where the specific wiring length is λ / 4 was described above, the specific wiring length can also be λ / 2. In this case, the specific wiring length for the surface layer, corresponding to the GLONASS band (1.60 GHz), is approximately 56.2 mm to 56.4 mm, and the specific wiring length for the inner layer is approximately 47.4 mm to 47.6 mm. Since the GLONASS band is a band from 1594.0625 MHz to 1609.375 MHz, the specific wiring length for the surface layer, in particular, lies within the range of 56.0 mm to 56.8 mm, and the specific wiring length for the inner layer lies within the range of 47.0 mm to 47.8 mm. Additionally, both λ / 4 and λ / 2 can be used as the specific wiring length.

[0051] When λ / 2 is used, in the example above, the specific wiring length for the surface layer corresponding to the BDS band (1.56 GHz) is approximately 57.8 mm, and the specific wiring length for the inner layer is approximately 48.6 mm. For example, the specific wiring length for the surface layer corresponding to the BDS band is in the range of 57.6 mm to 58.0 mm, and the specific wiring length for the inner layer is in the range of 48.4 mm to 48.8 mm.

[0052] Furthermore, the specific wiring length for the surface layer, corresponding to the GLONASS band (1.60 GHz), is approximately 56.3 mm to 56.5 mm, and the specific wiring length for the inner layer is approximately 47.3 mm to 47.5 mm. For example, the specific wiring length for the surface layer is in the range of 56.0 mm to 56.8 mm, and the specific wiring length for the inner layer is in the range of 47.0 mm to 47.8 mm.

[0053] It should be noted that the numerical ranges given above are only examples. If the number of parts on the circuit board varies, the dielectric constant εr will change due to the different base material, and thus the wiring length must be controlled. Furthermore, to ensure greater flexibility, the numerical range of specific wiring lengths described above can be expanded. Conversely, to expand the range of usable wiring lengths, the numerical range of specific wiring lengths described above can be narrowed.

[0054] It should be noted that, although the BDS band and the GLONASS band are given as examples of the specific band in the preceding description, the specific band can be a different frequency band. Furthermore, the specific band is not limited to the GHz band. For example, the specific band can be the operating frequency of a circuit or the like contained in the electronic device 10, or the operating frequency of a device connected to the electronic device 10. Furthermore, the specific band can be a frequency that is n times (n being a natural number) these operating frequencies. For example, the specific band can be a frequency that is an odd multiple of these operating frequencies.

[0055] For example, the specific band can be the frequency of a signal transmitted by the DC-DC converter. If, for example, the frequency is 2.10 GHz and λ / 2 is used, the specific wiring length for the surface layer is approximately 43.0 mm, and the specific wiring length for the inner layer is approximately 36.1 mm.

[0056] Furthermore, there can be a large number of specific bands. In this case, the unused wiring length for each specific band is determined, and the wiring pattern is generated so that it does not include any wiring with any of the specified wiring lengths. [Setting the shield clip interval]

[0057] The noise reduction effect of the shielding housing 15 depends on the intervals of the shielding clips 16. In particular, at points where the shielding clips 16 are not arranged, a gap of approximately several millimeters is created between the shielding housing 15 and the circuit board 12. Noise propagates through this gap.

[0058] Furthermore, the noise reduction effect can be improved by narrowing the intervals between the shielding clips 16, but increasing the number of shielding clips 16 to be placed increases the restrictions on the wiring pattern to be placed on the surface. In the present embodiment, the intervals of the shielding clips 16 are suitably designed within a range that can achieve a noise reduction effect, thereby reducing restrictions on the wiring pattern while suppressing noise.

[0059] In particular, the wavelength λ is calculated from the frequency f of the specific band and the propagation speed v in a vacuum using (Equation 5) above. Next, the specific interval for the shielding clips 16 is calculated based on the wavelength λ. For example, the specific interval is λ / 2. It should be noted that the specific interval can be λ / 4.

[0060] Next, the intervals for the shielding clips 16 are determined such that they are not the specific interval. For example, the intervals for the shielding clips 16 are determined such that they are closer together than the specific interval.

[0061] 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 (2.10 GHz) of the signal emitted by the DC-DC converter is 71.4 mm.

[0062] It should be noted that by widening the intervals of the shielding clips 16, the limitations on the wiring of the surface layer can be further reduced. Therefore, for example, by designing the intervals of the shielding clips 16 to be wider than 1 / 20 of the wavelength of a commonly used noise frequency (e.g., 9.4 mm for 1.6 GHz), the limitations on the wiring of the surface layer can be reduced more than by using intervals of less than or equal to 1 / 20 of the wavelength. In other words, the intervals of the shielding clips 16 can be narrower than the specific interval and wider than 1 / 20 of the wavelength.

[0063] It should be noted that, although there are a multitude of intervals between adjacent shielding clips 16, not all intervals need to be the same. In this case, all of the multitude of intervals are narrower than the specific interval. On the other hand, not all intervals need to be wider than 1 / 20 of the wavelength, and it is sufficient that at least one of the intervals is wider than 1 / 20 of the wavelength. Even in this case, the constraints on the wiring of the surface layer can be reduced more than if intervals of less than or equal to 1 / 20 of the wavelength are used. [Advantageous effects, etc.]

[0064] Inventions resulting from the disclosure of this description include, for example, the inventions described below. The following section describes the inventions resulting from the disclosure of this description, along with the advantageous effects achieved by the inventions and the like.

[0065] For example, according to one aspect of the present disclosure, the electronic device 10 comprises: a housing 11; a circuit board 12 arranged within the housing 11 and on which a plurality of circuit elements are mounted; and a shielding housing 15 provided on the circuit board and made of metal. Among the plurality of circuit elements, a circuit element requiring electromagnetic shielding is placed in a region of the circuit board 12 where the shielding housing 15 is provided.

[0066] Accordingly, a weight reduction can be achieved compared to enclosing the entire circuit board in a metal housing. Furthermore, noise reduction can be implemented for the circuit element requiring electromagnetic shielding. Therefore, both weight reduction and noise reduction can be achieved.

[0067] For example, the electronic device 10 further comprises: a plurality of shielding clips 16 that electrically connect the shielding housing 15 to a ground pattern of the circuit board 12. The intervals of the plurality of shielding clips 16 are designed based on a propagation characteristic of noise in a vacuum. For example, the propagation characteristic is the propagation speed or the wavelength.

[0068] Accordingly, the intervals of the shielding clips 16 can be designed taking into account an interval that has the effect of reducing noise in the specific band. Therefore, by widening the intervals while suppressing a reduction in the noise reduction effect, limitations on the wiring of the surface layer can be reduced.

[0069] For example, the intervals of the multitude of shielding clips can be smaller than a specific interval based on the propagation characteristics of the noise in a vacuum and larger than 1 / 20 of a wavelength of the noise.

[0070] Accordingly, the limitations on the wiring of the surface layer can be reduced more than when intervals of less than or equal to 1 / 20 of the wavelength are used, while suppressing a reduction of the noise reduction effect.

[0071] For example, the specific interval can be determined based on a wavelength λ, which is determined based on λ = v / f, where: f is a frequency of the noise; and v is a propagation speed in a vacuum, and the specific interval can be λ / 2 or λ / 4.

[0072] Therefore, the limitations on the wiring of the surface layer can be reduced, while a reduction in the noise suppression effect is appropriately suppressed.

[0073] For example, if the noise frequency is 2.10 GHz, the specific interval can be 71.4 mm; if the noise frequency is 1.60 GHz, the specific interval can be 93.7 mm; and if the noise frequency is 1.56 GHz, the specific interval can be 96.1 mm.

[0074] Therefore, the limitations on the wiring of the surface layer can be reduced, while a reduction in the noise suppression effect is appropriately suppressed.

[0075] For example, the circuit element requiring electromagnetic shielding may include a power supply circuit and an overload protection circuit. Accordingly, the noise of the circuit element requiring electromagnetic shielding can be reduced.

[0076] For example, the housing can be made of resin. Accordingly, a weight reduction of the electronic device 10 can be achieved.

[0077] For example, circuit board 12 includes a plurality of wiring layers. At least one section of the wiring 31 (or wiring 32) arranged within the plurality of wiring layers incorporates a meandering pattern 33 (or meandering pattern 34). The meandering pattern is configured based on different parameters for wiring located within different wiring layers of the plurality of wiring layers. These parameters include, for example, the propagation speed v, the wavelength λ, or the wiring length corresponding to a specific band.

[0078] Accordingly, a meandering pattern can be created for each wiring layer using parameters suitable for that layer. Therefore, for example, noise corresponding to a specific band can be suppressed.

[0079] For example, the meandering pattern may be included to give the wiring a length that is not 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).

[0080] This prevents the wiring from becoming a specific wiring length corresponding to the specific band, and thus noise corresponding to the specific band can be suppressed.

[0081] For example, different specific wiring lengths can be set for the different wiring layers. Accordingly, the length of wiring corresponding to a specific band can be calculated for each wiring layer using parameters suitable for that layer. Therefore, noise corresponding to the specific band can be suppressed. For example, the different wiring layers could be a surface layer and an inner layer.

[0082] For example, the specific wiring length can be set based on the specific frequency band, wiring width, and thickness of an insulator prepreg. For instance, the specific wiring length is calculated using equations 3 through 5 described above. Accordingly, the specific wiring length can be calculated with high accuracy by considering multiple parameters.

[0083] For example, the electronic device 10 may be intended for use in a vehicle. For example, the electronic device 10 may be an electronic control unit (ECU) comprising an active sound control unit (ASC) and / or an active noise control unit (ANC).

[0084] For example, a wiring method according to one aspect of the present disclosure is a wiring method for use in a circuit board 12 comprising a plurality of wiring layers, each containing a wiring 31 (or wiring 32), wherein the wiring at least partially comprises a meandering pattern 33 (or meandering pattern 34). The wiring method includes: setting the meandering pattern based on different parameters for a wiring arranged in different wiring layers of the plurality of wiring layers. Here, the parameters are, for example, the propagation speed v, the wavelength λ, or the wiring length corresponding to a specific band.

[0085] Accordingly, a meandering pattern can be created for each wiring layer using parameters suitable for that layer. Therefore, for example, noise corresponding to a specific band can be suppressed. [Other embodiments]

[0086] Although exemplary embodiments have been described above, the present disclosure is not limited to the embodiments described above.

[0087] For example, the electronic device according to the foregoing embodiments can be provided for a mobile device other than a vehicle. The mobile device can be, for example, an aircraft or a ship. Furthermore, the present disclosure can be implemented as such a mobile device other than a vehicle.

[0088] Furthermore, the general or specific aspects of this disclosure can be implemented as a system, a device, a method, an integrated circuit, a computer program, or a non-volatile, computer-readable recording medium, such as a CD-ROM. In addition, the general or specific aspects of this disclosure can be implemented as any combination of a system, a device, a method, an integrated circuit, a computer program, and a non-volatile, computer-readable recording medium.

[0089] Apart from the foregoing, forms obtained by making various modifications to respective embodiments that can be conceived by those skilled in the art, or forms realized by any combination of structural elements and functions in the respective embodiments within the core of the present disclosure, are included in the present disclosure. [Commercial Applicability]

[0090] An electronic device according to the present disclosure is, for example, useful as an electronic device in a vehicle. [List of reference symbols] 10 electronic devices 11 cases 12 circuit boards 13 upper chassis 14 lower chassis 15 shielding housings 16 shielding clips 21, 22, 31, 32 Wiring 33, 34 meander pattern 41, 51, 54 Ground conductor 42, 52 Insulation layer 43, 53 Wiring QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2005-159144

[0003]

Claims

Electronic device comprising: a housing; a circuit board arranged within the housing and on which a plurality of circuit elements are mounted; and a shielding housing provided on the circuit board and made of metal, wherein among the plurality of circuit elements a circuit element requiring electromagnetic shielding is placed in an area of ​​the circuit board where the shielding housing is provided. Electronic device according to claim 1, further comprising: a plurality of shielding clips that electrically connect the shielding housing to a ground pattern of the circuit board, wherein intervals of the plurality of shielding clips are set based on a propagation characteristic of a noise in a vacuum. Electronic device according to claim 2, wherein the intervals of the plurality of shielding clips are smaller than a specific interval based on the propagation characteristic of the noise in a vacuum and larger than 1 / 20 of a wavelength of the noise. Electronic device according to claim 3, wherein the specific interval is determined based on a wavelength λ which is determined based on λ = v / f, where: f is a frequency of the noise; and v is a propagation speed in a vacuum, and the specific interval is λ / 2 or λ / 4. Electronic device according to claim 3, wherein when the noise frequency is 2.10 GHz, the specific interval is 71.4 mm, when the noise frequency is 1.60 GHz, the specific interval is 93.7 mm, and when the noise frequency is 1.56 GHz, the specific interval is 96.1 mm. Electronic device according to any one of claims 1 to 5, wherein the circuit element requiring electromagnetic shielding comprises a power supply circuit and an overload protection circuit. Electronic device according to any one of claims 1 to 5, wherein the housing is made of resin. Electronic device according to one of claims 1 to 5, wherein the circuit board includes a plurality of wiring layers, at least one section of the wiring arranged in the plurality of wiring layers includes a meandering pattern, and the meandering pattern is set based on different parameters for wiring arranged in different wiring layers of the plurality of wiring layers. Electronic device according to claim 8, wherein the meandering pattern is included to give the wiring a length that is not a specific wiring length corresponding to a specific frequency band. Electronic device according to claim 9, wherein different specific wiring lengths are designed for the different wiring layers. Electronic device according to claim 9, wherein the specific wiring length is designed based on the specific frequency band, a wiring width and a thickness of an insulator prepreg. Electronic device according to any one of claims 1 to 5, wherein the electronic device is intended for use in a vehicle. Electronic device according to claim 12, wherein the electronic device is an electronic control unit (ECU) comprising an active sound control unit (ASC) and / or an active noise control unit (ANC).

Images