Electronic devices

Abstract

To provide an electronic device which is excellent in assemblability and suitable for downsizing.SOLUTION: A housing 2 of an electronic device is a resin molded product integrally having an attachment part 15 and formed as a MID (a molded interconnect device) in which wiring patterns are formed on a surface of the interior of the housing 2. The attachment part 15 is provided with a conductive part for electrically connecting the wiring patterns 40a, 40b of the housing 2 with wiring patterns 30a, 30b of a circuit board 3.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an electronic device including a circuit board on which electronic components are mounted.

Background Art

[0002] Conventionally, for example, electronic devices mounted on vehicles have been provided in which a circuit board is housed in the internal space of a housing that forms the outer outline of the device. In recent years, attempts have been made to increase the mounting area by using MID (Molded Interconnect Device) as a molded circuit component. For example, in Patent Document 1, an injection-molded MID circuit support and a circuit board are arranged to face each other, and are electrically connected via a pair of electrical contacts, that is, a MID contact element and a coupling interface contact element. As described above, the combination of the MID circuit support and the circuit board allows the planar circuit structure of the circuit board to be expanded into a three-dimensional circuit structure. Therefore, it is also conceivable to apply such a structure to the above electronic device and incorporate the circuit board together with the MID circuit support into the housing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, in the above structure, when combining the MID circuit support and the circuit board, coupling components such as clips and spring members or an adhesive portion is required, which leads to an increase in the number of components or assembly man-hours. Further, the MID circuit support is bulky in the thickness direction of the circuit board, which may possibly cause an increase in the size of the housing of the electronic device.

[0005] This invention has been made in view of the above circumstances, and its purpose is to provide an electronic device that is easy to assemble and suitable for miniaturization. [Means for solving the problem]

[0006] According to the invention described in claim 1, by forming wiring patterns (40a, 40b, 60a, 60b) on the inner surface of the housing (2), the mounting area can be increased without increasing the size of the circuit board (3), resulting in a configuration suitable for miniaturization. Furthermore, when mounting the circuit board to the mounting parts (15, 151, 152, 153, 154), it becomes possible to electrically connect the wiring patterns of the housing and the wiring patterns of the circuit board (30a, 30b, 51a, 51b) via the conductive parts, making such electrical connection work easy. [Brief explanation of the drawing]

[0007] [Figure 1] Perspective view showing the overall appearance of the electronic device in the first embodiment. [Figure 2] Cross-sectional view showing the internal structure of an electronic device. [Figure 3] Plan view showing a circuit board [Figure 4] A cross-sectional view showing a magnified view of the area near the mounting portion of the circuit board. [Figure 5] Plan view showing the circuit board together with electronic components in the second embodiment. [Figure 6] A cross-sectional view showing the vicinity of the mounting area of ​​the circuit board, along with the electronic components, in an enlarged view. [Figure 7] A cross-sectional view showing a magnified view of the area near the connector mounting portion of the circuit board. [Figure 8] Plan view of the circuit board in the third embodiment [Modes for carrying out the invention]

[0008] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. In each embodiment, substantially identical components will be denoted by the same reference numerals, and their descriptions will be omitted.

[0009] <First Embodiment> The first embodiment will be described with reference to Figures 1 to 4. The electronic device 1 shown in Figure 1 is, for example, an air conditioning control unit (ACECU) mounted in a vehicle. The housing 2 that forms the outer casing of the electronic device 1 is a thin rectangular box as a whole, and a circuit board 3 is housed inside it as shown in Figure 2.

[0010] The circuit board 3 is a rectangular printed circuit board with a wiring pattern formed on the surface of a substrate made of an electrically insulating material. In addition to the connector 6 shown in Figure 2, the circuit board 3 may also have electronic components 7 (see Figures 5 and 6) such as control ICs, switching elements, resistors, and capacitors, which will be described later, mounted on it, and the circuit is formed by the wiring pattern and the electronic components 7.

[0011] Connector 6 faces the outside from the front side of the housing 2, and a cable from an external device (not shown) is connected to it, electrically relaying the external device and the circuit on the circuit board 3. In actual vehicle installation, the circuit board 3 may be oriented vertically, but for the sake of explanation below, in Figure 2, the side with the connector 6 opening will be considered the front, and the opposite side will be considered the rear or innermost part. Also, in Figures 1 and 2, the thickness direction of the circuit board 3, which is the vertical direction, will be defined as the Z direction. Furthermore, in the planar direction of the circuit board 3, the direction along one side of the peripheral part of the board 3 will be defined as the X direction, and the direction perpendicular to the X direction will be defined as the Y direction.

[0012] The housing 2 is formed by combining the main body case 10 and the cover 11 in the Y direction, and has an internal space for housing the circuit board 3 and the connector 6. Of these, the main case 10 is a first housing member into which the circuit board 3 is inserted from the front side in the Y direction, as shown in Figures 1 and 2, and is formed from, for example, a synthetic resin material. The main case 10 has upper and lower wall portions 10a and 10b, which are slightly larger than the circuit board 3, as well as left and right wall portions 10c and 10d and a back wall portion 10e, all integrated together, and has a thin, rectangular tube shape with the back closed.

[0013] As shown in Figure 1, a stepped portion 12 is formed on the upper wall portion 10a of the main case 10, matching the outer shape of the connector 6 on the front side in the Y direction (see Figure 7). Locking claws 13 (see Figure 1) are provided on the upper wall portion 10a at two locations, on the left and right sides of the stepped portion 12. Although not shown in the illustration, two locking claws 13 are also provided on the lower wall portion 10b of the main case 10, so that the cover 11 is locked in place by four locking claws 13 on both the upper and lower sides.

[0014] The cover 11 is a second housing member formed from, for example, a synthetic resin material, and is a rectangular plate that covers the area around the connector 6 on the opening 10f side of the main case 10. Four locking pieces 14 (two on the upper side are shown in Figure 1) corresponding to the four locking claws 13 are provided on both the upper and lower sides of the cover 11. The locking pieces 14 are rectangular frame-shaped extending inward in the Y direction, and as they lock onto the locking claws 13 due to their own flexibility, the cover 11 is assembled to the main case 10 in a way that allows it to be locked and detached.

[0015] The peripheral portion of the cover 11 is composed of upper and lower protrusions 11a and 11b (see Figure 7) that project inward in the Y direction, and left and right protrusions 11c and 11d (see Figure 2). Of these, the left and right protrusions 11c and 11d have a stepped shape that forms an L-shape or inverted L-shape when viewed from the Z direction, as shown in Figure 2, and connect to and fit with the stepped portion of the opening 10f of the main case 10 (the front ends of the left and right wall portions 10c and 10d).

[0016] Next, the configuration of the mounting portion 15 for the circuit board 3 inside the housing 2 will be explained with reference to Figures 2, 4, and 7. Here, the mounting portions 15 of the present embodiment are provided at a plurality of locations (for example, 4 locations) as shown in the cross-sectional view of FIG. 2, and in order to distinguish each of the mounting portions 15, they are represented by reference numerals "151", "152", "153", and "154". Furthermore, the two mounting portions 151 and 152 on the inner side of the circuit board 3 have the same shape as each other, and the two mounting portions 153 and 154 on the front side also have the same shape as each other, so the description will focus on the mounting portions 152 and 154 on the right side shown in the enlarged views of FIG. 4 and FIG. 7. Note that the mounting portion 15 includes the rib 16 shown in FIG. 2 in addition to the four mounting portions 151 to 154.

[0017] That is, as shown in FIG. 2, on the inner wall of the inner wall portion 10e of the main body case 10, a rib 16 (hereinafter also referred to as "central rib 16") is provided positioned at the central portion in the X direction, the mounting portion 151 is provided at an intermediate position between the central rib 16 and the left wall portion 10c, and the mounting portion 152 is provided at an intermediate position between the central rib 16 and the right wall portion 10d.

[0018] The central rib 16 is a vertical rib that protrudes from the inner wall of the inner wall portion 10e toward the front side in the Y direction, and extends in a band shape from the lower wall portion 10b to the upper wall portion 10a. Thereby, the central rib 16 fits into the notch 3c of the circuit board 3 to suppress rattling of the board 3 in the X direction, and functions as a reinforcing rib on the inner wall portion 10e side.

[0019] As shown in FIG. 4, the mounting portion 152 is constituted by a pair of upper and lower ribs 17a and 17b that sandwich the two surfaces 3a and 3b of the circuit board 3. Among these, the rib 17a is a plate-shaped first rib (hereinafter also referred to as "upper rib 17a") that protrudes from the inner wall of the inner wall portion 10e toward the front side in the Y direction, and extends from the upper wall portion 10a to a position where it abuts against the upper surface 3a of the circuit board 3. On the other hand, the rib 17b is a plate-shaped second rib (hereinafter also referred to as "lower rib 17b") that protrudes from the inner wall of the inner wall portion 10e toward the front side in the Y direction, and extends from the lower wall portion 10b to a position where it abuts against the lower surface 3b of the circuit board 3.

[0020] Furthermore, as shown in Figure 4, the upper rib 17a and the lower rib 17b face each other with a gap t equal to the thickness of the circuit board 3, and their respective opposing surfaces are contact surfaces 19a and 19b with the circuit board 3. In addition, the upper rib 17a and the lower rib 17b have tapered surfaces 18a and 18b that are inclined so that the gap t between them widens as it moves toward the front in the Y direction. In this case, the tapered surface 18a and contact surface 19a of the upper rib 17a and the tapered surface 18b and contact surface 19b of the lower rib 17b form a funnel shape when viewed from the X direction.

[0021] As a result, the circuit board 3 can be attached to the mounting portions 151 and 152 by inserting the circuit board 3 from the opening 10f side of the main case 10 and abutting it toward the back. In this case, the rear side of the circuit board 3 in the Y direction is guided by the tapered surface 18a of the upper rib 17a or the tapered surface 18b of the lower rib 17b on the mounting portions 151 and 152, and is held in place without rattling in the Z direction by being pressed between the two contact surfaces 19a and 19b.

[0022] In contrast, the mounting portions 153 and 154 are provided on the inner wall immediately inside the protruding portions 11c and 11d of the cover 11 shown in Figure 2, and are located on the outer side of the connector 6 in the X direction. That is, the mounting portion 153 is positioned between the left protruding portion 11c of the cover 11 and the connector 6, and the mounting portion 154 is positioned between the right protruding portion 11d and the connector 6.

[0023] As shown in Figure 7, the mounting portion 154 is composed of a pair of upper and lower ribs 21a and 21b that sandwich both sides 3a and 3b of the circuit board 3. Of these, rib 21a is a plate-shaped first rib (hereinafter also referred to as "upper rib 21a") that protrudes from the inner wall of the cover 11 toward the back in the Y direction and extends from the upper protruding portion 11a to a position where it abuts against the upper surface 3a of the circuit board 3. On the other hand, rib 21b is a plate-shaped second rib (hereinafter also referred to as "lower rib 21b") that protrudes from the inner wall of the cover 11 toward the back in the Y direction and extends from the lower protruding portion 11b to a position where it abuts against the lower surface 3b of the circuit board 3.

[0024] Furthermore, the upper rib 21a and lower rib 21b of the mounting portion 154 shown in Figure 7 have tapered surfaces 22a, 22b and contact surfaces 23a, 23b that form a funnel shape when viewed from the X direction, similar to the upper rib 17a and lower rib 17b of the mounting portion 152 shown in Figure 4. This allows the circuit board 3 to be attached to the mounting portions 153 and 154 of the cover 11 so that it abuts against the inner wall of the cover 11 between the respective ribs 21a and 21b. In this case, the circuit board 3 is guided by the tapered surface 22a of the upper rib 21a or the tapered surface 22b of the lower rib 21b on its front side in the Y direction, and is held in place without rattling in the Z direction by being pressed between the two contact surfaces 23a and 23b.

[0025] In the mounting sections 151 to 154 described above, the Z-direction dimensions of the upper ribs 17a and 21a are set to be larger than the Z-direction dimensions of the lower ribs 17b and 21b. This is a dimension setting that matches the size of electronic components 7 such as connectors 6 that are mounted or housed on the upper surface 3a of the circuit board 3, and contributes to the miniaturization of the entire housing 2. The mounting sections 151 to 154 only need to be integrally provided on the main case 10 or cover 11 as a means of mounting the circuit board 3, and the dimensions and shapes of each rib 17a, 17b, 21a, and 21b can be changed as appropriate.

[0026] Here, the circuit board 3 of this embodiment will be described. As shown in Figures 2 and 3, a ground pattern 30a, for example, is formed on the upper surface 3a of the circuit board 3 as a wiring pattern, and in Figure 3, for the sake of explanation, the illustration of electronic components 7 such as the connector 6 is omitted. In other words, the wiring pattern refers to various conductive patterns made of conductive material such as copper foil, and as an example, the ground pattern 30a shown in Figure 3 is provided on the upper surface 3a of the circuit board 3. In addition, a notch 3c is formed on the inner edge of the circuit board 3 in the Y direction, which is cut out to fit with the central rib 16.

[0027] As shown in Figure 3, the ground pattern 30a includes a ground pattern section 31a, connection pattern sections 321a, 322a, and ground pads 331a, 332a. The ground pattern section 31a grounds each part connected to it and is formed in a rectangular shape that extends from the center in the Y direction of the circuit board 3 to the vicinity of the notch 3c and outward in the X direction beyond the mounting sections 151 and 152. The connection pattern sections 321a and 322a are separated from each other by the same distance L1 as the mounting sections 151 and 152, and each extends inward from the ground pattern section 31a in the Y direction.

[0028] The ground pads 331a and 332a are copper foil portions located on the edges of the circuit board 3, on the extensions of the connection pattern portions 321a and 322a, respectively, and are formed to align with the contact surfaces 19a of the ribs 17a of the mounting portions 151 and 152 (see ground pad 332a in Figure 4). Also, as shown in Figure 3, the ground pad 331a is connected to the ground pattern portion 31a via the connection pattern portion 321a, and the ground pad 332a is connected to the ground pattern portion 31a via the connection pattern portion 322a.

[0029] As described above, in this embodiment, the components on the upper surface 3a side of the circuit board 3 are denoted with the symbol "a", and the components on the lower surface side are denoted with the symbol "b" to distinguish between the components on both sides. Although detailed illustrations are omitted, a ground pattern 30b (see dashed leader line in Figure 3) is also formed on the lower surface 3b of the circuit board 3. In Figure 3, for the sake of explanation, the ground pattern 30b on the lower surface 3b is shown as an example of a symmetrically formed pattern identical to the ground pattern 30a on the upper surface 3a, and is indicated by a dashed leader line. Therefore, the ground pattern 30b, like the ground pattern 30a, has a ground pattern section 31b, connection pattern sections 321b, 322b (only the right-hand connection pattern section 322b is shown in Figure 4), and ground pads 331b, 332b (only the right-hand ground pad 332b is shown in Figure 4). Furthermore, the cross-sectional view in Figure 4 is a schematic diagram, showing the cross-sections of the ground patterns 30a and 30b described above with thick lines.

[0030] Furthermore, the ground patterns 30a and 30b on the circuit board 3 can be formed in patterns corresponding to the mounting area of ​​the electronic components 7, and of course, they can be formed in mutually different patterns. In addition, either one of the ground patterns 30a or 30b may be formed on the circuit board 3 (see Figure 8 described later), and the one of the ground patterns may be formed to be in contact with either one of the ribs 17a or 17b of the mounting portions 151 and 152.

[0031] Now, the housing 2 of this embodiment is a resin molded body in which the mounting portions 151 to 154 described above are integrally formed with the main body case 10 or cover 11 using the synthetic resin material, and is configured as a MID (Molded Interconnect Device) in which a wiring pattern is formed with a conductive metal film on the inner surface of the housing 2, that is, on the inner wall of at least one of the main body case 10 and cover 11. Furthermore, in this embodiment, the main body case 10 is used as an example in which the wiring pattern is applied, while an example in which the cover 11 is applied will be described later as another embodiment.

[0032] Methods for manufacturing a three-dimensional circuit molded body (MID) include the double-pass molding method, the single-pass molding method, and the insert molding method. While a detailed explanation is omitted, the double-pass molding method involves forming a masking layer in areas where wiring patterns are unnecessary through double molding. The single-pass molding method is the LDS (Laser Direct Structuring) method, which activates a catalyst by laser irradiation in the area where the wiring pattern is to be applied. The insert molding method involves integrally forming a film circuit with the wiring pattern as an insert in a resin molded body. By adopting a manufacturing method appropriate to the form of the target main body case 10 or cover 11, various wiring patterns can be formed.

[0033] Here, the wiring pattern of the main case 10 includes an upper ground pattern 40a and a lower ground pattern 40b formed on the inner wall of the main case 10, which are at ground potential. For example, the upper ground pattern 40a includes a ground pattern portion 41a (shown only in Figure 4) formed on the upper wall portion 10a side of the main body case 10, and connection pattern portions 421a and 422a (shown in Figures 2 and 4) formed on the ribs 17a of the mounting portions 151 and 152.

[0034] The ground pattern section 41a can be formed to extend using the entire inner wall area on the upper wall section 10a side, as shown by the cross-section indicated by the thick line in Figure 4. The connection pattern portions 421a and 422a are formed to cover the entire rib 17a of the mounting portions 151 and 152, and both are connected to the ground pattern portion 41a. In this way, the connection pattern portions 421a and 422a that cover each rib 17a, and in particular the portions of the connection pattern portions 421a and 422a on the contact surface 19a of each rib 17a, are conductive parts that are electrically connected to the ground pads 331a and 332a of the circuit board 3.

[0035] Although detailed illustrations are omitted, the ground pattern 40b includes a ground pattern section 41b (shown only in Figure 4) formed on the lower wall section 10b of the main case 10, and connection pattern sections 421b and 422b (only the right-hand connection pattern section 422b is shown in the same figure) formed on the ribs 17b of the mounting sections 151 and 152. The ground pattern portion 41b can be formed to extend using the entire inner wall on the lower wall portion 10b side, as shown by the cross-section of the thick line in Figure 4, and the connecting pattern portions 421b and 422b connected to it are formed to cover the entirety of each rib 17b. As a result, the portions of the connecting pattern portions 421b and 422b on the contact surface 19b of each rib 17b are conductive parts that are electrically connected to the ground pads 331b and 332b of the circuit board 3.

[0036] The operation of the configuration related to the above-mentioned enclosure 2 will be explained. When mounting the circuit board 3 inside the enclosure 2, the main body case 10 and cover 11 are prepared in advance by printing ground patterns 40a and 40b using the manufacturing method described above. Then, the circuit board 3 can be mounted to the main body case 10 simply by inserting the circuit board 3 from the opening 10f side of the main body case 10 and pushing it towards the back (see Figure 2).

[0037] In this case, the inner side of the circuit board 3 in the Y direction, that is, the ground pad side indicated by reference numerals 331a and 332a in Figure 3, is guided by the tapered surface 18a of the upper rib 17a or the tapered surface 18b of the lower rib 17b in the mounting portions 151 and 152 (see Figure 4), and is pressed and mounted between the two contact surfaces 19a and 19b, thereby being held in a position where it cannot move in the Z direction.

[0038] As a result, when the circuit board 3 is attached to the mounting parts 151 and 152, the ground pads 331a, 332a, 331b, and 332b on both sides 3a and 3b are sandwiched and made surface contact between the conductive parts (connection pattern parts 421a and 422a) of the contact surface 19a of the upper rib 17a and the conductive parts (connection pattern parts 421b and 422b) of the contact surface 19b of the lower rib 17b. This allows the ground patterns 30a and 30b of the circuit board 3 to be electrically connected to the ground patterns 40a and 40b of the main body case 10.

[0039] On the other hand, the circuit board 3 is attached to the cover 11 by abutting it against the ribs 21a and 21b of the mounting portions 153 and 154 (see Figures 2 and 7). In this case as well, the circuit board 3 is guided by the tapered surface 22a of the upper rib 21a or the tapered surface 22b of the lower rib 21b on its front side in the Y direction, and is pressed and attached between the two contact surfaces 23a and 23b, thereby being held in a position where it cannot move in the Z direction. Alternatively, the circuit board 3 may be attached to the cover 11 first, and then the cover 11 may be inserted from the circuit board 3 into the opening 10f of the main body case 10 and combined with the main body case 10, thereby attaching the circuit board 3 to the mounting parts 151 to 154 inside the housing 2.

[0040] As described above, the housing 2 in the electronic device 1 of this embodiment is a resin molded product integrally having mounting portions 151 to 154, and is configured as a MID with a wiring pattern formed on the inner surface of the housing 2. For example, among the four mounting portions 151 to 154, the mounting portions 151 and 152 located at the back of the main body case 10 are provided with conductive portions for electrically connecting the wiring pattern of the main body case 10 and the wiring pattern of the circuit board 3. These conductive portions are, for example, connection pattern portions 422a and 422b formed on at least the contact surfaces 19a and 19b of the ribs 17a and 17b described above (see Figure 4).

[0041] According to this, by forming wiring patterns such as ground patterns 40a and 40b on the inner surface of the housing 2, the mounting area can be increased without increasing the size of the circuit board 3, resulting in a configuration suitable for miniaturization. Furthermore, when mounting the circuit board 3 to the mounting parts 151 and 152, it becomes possible to electrically connect the wiring pattern of the main case 10 and the circuit board 3 via the conductive parts, making such electrical connection work easy.

[0042] The wiring patterns of the circuit board 3 or the housing 2 include ground patterns 30a, 30b or 40a, 40b (see Figure 4) that are at ground potential, and the conductive parts are formed as ground patterns 40a, 40b in the main body case 10 of the housing 2. According to this, conductive parts can be easily formed as ground patterns 40a and 40b on the housing 2, which is a resin molded body. Furthermore, by extending the ground patterns 40a and 40b to the housing 2 side, the circuit board 3 can be miniaturized accordingly, resulting in an overall inexpensive and compact configuration.

[0043] The mounting portions 151 and 152 are formed by a plurality of ribs 17a and 17b that sandwich both sides 3a and 3b of the circuit board 3. This allows the ribs 17a and 17b to hold the circuit board 3 so that it does not rattle in the thickness direction. Furthermore, separate parts such as clips and screws for mounting or fixing the circuit board 3 are not required, and the electrical connection work related to the conductive parts described above is also substantially unnecessary, making the mounting of the circuit board 3 as easy as possible.

[0044] The plurality of ribs 17a, 17b include a first rib 17a that abuts against the wiring pattern on one side 3a of the circuit board 3, or a second rib 17b that abuts against the wiring pattern on the other side 3b, and the conductive portion is formed on at least the abutting portion of the first rib 17a or the second rib 17b (for example, the contact surfaces 19a, 19b shown in Figure 4). According to this, by inserting the circuit board 3 between the first rib 17a and the second rib 17b, an electrical connection between the wiring pattern of the main body case 10 and the circuit board 3 can be reliably established via the contacting conductive parts. Note that the "contacting parts" mentioned above are not limited to surface contact at the contact surfaces 19a and 19b illustrated in Figure 4, but may also be configured to contact the wiring pattern of the circuit board 3 via, for example, line contact.

[0045] <Other Embodiments> Figures 5 to 8 show the second and third embodiments of the present invention. The following will describe the substantial differences from the embodiments described above.

[0046] The circuit board 50 of this second embodiment, shown in Figure 5, differs from the circuit board 3 of the first embodiment in the following respects. Specifically, a plurality of electronic components 7, including the connector 6, are mounted on the upper surface 50a of the circuit board 50, and a signal line pattern 51a is formed as a wiring pattern corresponding to the placement positions of the connector 6 and electronic components 7. As shown in Figure 5, the signal line pattern 51a is configured to include, for example, first to fourth signal line pattern sections 521a to 524a and pads 531a to 534a at their respective ends.

[0047] In the left rear of the circuit board 50 shown in Figure 5, the straight first signal line pattern 521a has one end electrically connected to the electronic component 7 (the electronic component 7 on the left) and the other end connected to the pad 531a on the rear edge of the circuit board 50. Similarly, the second signal line pattern 522a on the right rear has one end connected to the electronic component 7 (the electronic component 7 on the right) and the other end connected to the pad 532a on the rear edge of the circuit board 50. On the left front of the circuit board 50, the L-shaped third signal line pattern 523a has one end electrically connected to the left side of the connector 6 and the other end connected to the pad 533a on the front edge of the circuit board 50. Similarly, the fourth signal line pattern 524a on the right front has one end connected to the right side of the connector 6 and the other end connected to the pad 534a on the front edge of the circuit board 50.

[0048] Although detailed illustrations are omitted, a signal line pattern 51b (see dashed leader lines in Figure 5) is also formed on the lower surface 50b of the circuit board 50. In Figure 5, for the sake of explanation, the signal line pattern 51b on the lower surface 50b is shown as being formed symmetrically with the same pattern as the signal line pattern 51a on the upper surface 50a, and this is indicated by a dashed leader line. Therefore, the signal line pattern 51b, like the signal line pattern 51a, includes first to fourth signal line pattern sections 521b, 522b, 523b, and 524b, and each end is provided with copper foil pads 531b, 532b, 533b, and 534b.

[0049] Furthermore, the signal line patterns 51a and 51b on the circuit board 50 can be formed in patterns corresponding to the arrangement of the electronic components 7, and of course, they can be formed in mutually different patterns. Also, either one of the signal line patterns 51a or 51b may be formed on the circuit board 50.

[0050] On the other hand, inside the housing 2 of this second embodiment, signal line patterns 60a and 60b are formed as wiring patterns that replace the ground patterns 30a and 30b (see Figures 6 and 7). The upper signal line pattern 60a inside the housing 2 includes a signal line pattern section 61a formed on the upper wall 10a side of the main case 10, connection pattern sections 621a and 622a formed on the ribs 17a of the mounting sections 151 and 152 (only the right-hand connection pattern section 622a is shown in Figure 6), and connection pattern sections 623a and 624a formed on the ribs 21a of the mounting sections 153 and 154 (only the right-hand connection pattern section 624a is shown in Figure 7).

[0051] As shown by the thick cross-sections in Figures 6 and 7, the signal line pattern section 61a can be formed in a straight line on the inner wall of the upper wall section 10a, connecting the rib 17a of the mounting section 152 in Figure 6 and the rib 21a of the mounting section 154 in Figure 7. Although not shown in the illustrations, the signal line pattern section 61a can also be formed to connect the rib 17a of the mounting section 151 and the rib 21a of the mounting section 153 in a straight line, or it can be formed into an intricate and complex pattern.

[0052] Furthermore, the connection pattern sections 621a to 624a are formed to cover the entirety of the corresponding ribs 17a and 21a, respectively, and are connected to the signal line pattern section 61a of the upper wall section 10a. In this way, the connection pattern sections 621a to 624a (only connection pattern sections 622a and 624a are shown in Figures 6 and 7) formed on the contact surfaces 19a and 23a of each rib 17a and 21a are conductive sections that are electrically connected to the pads 531a to 534a of the circuit board 50.

[0053] The signal line pattern 60b on the lower side of the housing 2 shown in Figures 6 and 7 is formed symmetrically to the signal line pattern 60a on the upper side, and includes a signal line pattern section 61b formed on the lower wall section 10b of the main body case 10, connection pattern sections 621b and 622b formed on the ribs 17b of the mounting sections 151 and 152 (only the right-side connection pattern section 622b is shown in Figure 6), and connection pattern sections 623b and 624b formed on the ribs 21b of the mounting sections 153 and 154 (only the right-side connection pattern section 624b is shown in Figure 7).

[0054] The signal line pattern section 61b, like the signal line pattern section 61a, is formed in a straight line on the inner wall of the lower wall section 10b, connecting the rib 17b of the mounting section 152 and the rib 21b of the mounting section 154 (see Figures 6 and 7), or in a straight line connecting the rib 17a of the mounting section 151 and the rib 21a of the mounting section 153 (not shown), or it can be formed in an intricate and complex pattern.

[0055] Furthermore, the connection pattern sections 621b to 624b are formed to cover the entirety of the corresponding ribs 17b and 21b, respectively, and are connected to the signal line pattern section 61b of the lower wall section 10b. In this way, at least the connection pattern sections 621b to 624b (only connection pattern sections 622b and 624b are shown in Figures 6 and 7) formed on the contact surfaces 19b and 23b of each rib 17b and 21b are conductive parts that are electrically connected to the pads 531b to 534b of the circuit board 50.

[0056] As described above, the wiring pattern of the circuit board 50 in this second embodiment includes, for example, signal line patterns 51a and 51b that are connected to the connector 6 and the electronic component 7, and the conductive parts are formed as wiring patterns on the housing 2 side (for example, signal line patterns 60a and 60b) and are electrically connected to the signal line patterns 51a and 51b of the circuit board 50. According to this, conductive parts can be easily formed as wiring patterns on the housing 2, which is a resin molded body. Furthermore, the signal line patterns 60a and 60b can be extended to the housing 2, thereby enabling miniaturization of the circuit board 50, and thus achieving the same effects as the first embodiment described above.

[0057] The connector 6 mounted on the circuit board 50 is connected to the wiring pattern of the housing 2 via the conductive parts of the mounting portions 153 and 154. This allows for the inclusion of the wiring pattern of the housing 2 (e.g., the signal line patterns 60a and 60b in Figure 7) in addition to the circuit on the circuit board 50 as the circuit between the connector 6 and other electronic components 7, thereby increasing the mounting area. Furthermore, even if the mounting portions 153 and 154 of the circuit board 50 are located near the connector 6, the wiring pattern can be formed without restricting the wiring of the connector 6. In addition, the relative positional relationship between the connector 6 and the mounting portions 153 and 154 can increase the design flexibility of the wiring pattern.

[0058] Figure 8 shows the circuit board 3 of the third embodiment, and the differences from the first embodiment will be explained. As shown in Figure 8, in this third embodiment, the circuit board 3 has a ground pattern 30a formed only on the upper surface 3a, and notches 3e and 3f are provided instead of the notch 3c in Figure 3. The notches 3e and 3f are formed by cutting out the portions of the ground pads 331a and 332a in Figure 3, and the portions of the connection patterns 321a and 322a in Figure 8 function as ground pads.

[0059] Although not shown in the illustration, the upper and lower ribs in the mounting portions 151 and 152 of this third embodiment are referred to as "ribs 17a' and 17b'" to distinguish them from the ribs 17a and 17b of the first embodiment. Each rib 17a', 17b' in the mounting sections 151, 152 protrudes from the back wall section 10e so as to sandwich the connecting pattern sections 321a, 322a at their tip. In this case, each rib 17a', 17b' is located at the positions of the mounting portions 151, 152 in Figure 2 (a distance of L1), and is connected to each other at the base end of the upper and lower ribs 17a', 17b' so as to fit with the notches 3e, 3f. In other words, each rib 17a', 17b' has a base end that protrudes forward in the Y direction, similar to the central rib 16 in the first embodiment, and its tip also protrudes forward in the Y direction compared to the ribs 17a, 17b in the first embodiment.

[0060] As a result, when the circuit board 3 is attached to the mounting parts 151 and 152, it is press-fitted into the tip portions of each rib 17a' and 17b' so as to be held immobile in the Z direction, and the base ends of the ribs 17a' and 17b' engage with the notches 3e and 3f to hold the board 3 so as not to wobble in the X direction.

[0061] In this way, the ribs 17a' and 17b' can function as positioning or holding functions for the circuit board 3 by fitting and locking with the notches 3e and 3f, and as reinforcing ribs on the back wall 10e side of the mounting parts 151 and 152. Furthermore, since the conductive parts are formed on the ribs 17a' and 17b' in portions including the contact surface 19a with the connection pattern parts 321a and 322a, the electrical connection work is substantially unnecessary, as in the above embodiment.

[0062] As described above, in the circuit board 3 of this third embodiment, notches 3e and 3f are formed at positions corresponding to the mounting portions 151 and 152, so that the mounting portions 151 and 152 and the notches 3e and 3f can be held together, and the positioning of the circuit board 3 can be performed with a simple configuration in which the notches 3e and 3f are the mounting portions.

[0063] It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented by appropriately modifying the embodiments or modified versions described above. The housing 2 is a resin molded product integrally having a mounting portion 15, and is configured as a MID with a wiring pattern formed on the inner surface of the housing 2. In this case, not only the wiring pattern but also electronic components may be arranged on the inner surface of the housing 2. For example, the electronic component 7 shown in Figure 6 may be incorporated together with the signal line pattern 60a on the upper wall portion 10a side of the main body case 10.

[0064] The mounting portion 15 in the housing 2 is not limited to the mounting portions 151 to 154 described above, and its number and arrangement can be changed as appropriate, and it may be composed of ribs other than those described above. Furthermore, the electronic components include the connector 6, and its number and arrangement are not limited to the embodiments shown in the drawings. The conductive portion is provided to cover all of the upper and lower ribs 17a, 17b, 21a, and 21b, but it is sufficient if it is provided at the contact point with the wiring pattern of the circuit board on any one of these ribs 17a, 17b, 21a, and 21b, and is used for electrical connection between the circuit board and the wiring pattern of the housing 2.

[0065] This disclosure is described in accordance with examples (embodiments), but it is understood that this disclosure is not limited to such examples or structures. This disclosure also includes various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure. [Explanation of symbols]

[0066] In the drawing, 1...electronic device, 2...housing, 3, 50...circuit board, 6...connector (electronic component), 7...electronic component, 15, 151~154...mounting part, 17a, 17b, 21a, 21b...rib, 30a, 30b...ground pattern (wiring pattern), 40a, 40b...ground pattern (wiring pattern), 51a, 51b...signal line pattern (wiring pattern), 60a, 60b...signal line pattern (wiring pattern).

Claims

1. A circuit board (3, 50) on which electronic components (7) are mounted, A housing (2) having an internal space for housing the circuit board and forming the outer casing of an electronic device, and having mounting parts (15, 151, 152, 153, 154) for mounting the circuit board, The housing is a resin molded product integrally having the mounting portion, and is configured as a MID (Molded Interconnect Device) with a wiring pattern formed on the surface of the housing facing the internal space. The mounting portion is formed by a plurality of ribs (17a, 17b, 21a, 21b) that sandwich both sides of the circuit board, and these plurality of ribs include a first rib that abuts against one side of the circuit board and a second rib that abuts against the other side of the circuit board. An electronic device (1) is provided with conductive parts in the contact portion with the circuit board of at least one of the first rib and the second rib for electrically connecting the wiring patterns of the housing (40a, 40b, 60a, 60b) and the wiring patterns of the circuit board (30a, 30b, 51a, 51b).

2. The wiring pattern of the circuit board includes signal line patterns (51a, 51b) connected to the electronic components, and the conductive portion is formed as a wiring pattern (60a, 60b) on the housing side and electrically connected to the signal line patterns, as described in claim 1.

3. The electronic device according to claim 1, wherein the wiring pattern of the circuit board or the wiring pattern of the housing includes ground patterns (30a, 30b, 40a, 40b) that are at ground potential, and the conductive part is formed as the ground pattern (40a, 40b) of the housing.

4. The electronic device according to claim 1, wherein the circuit board has notches (3e, 3f) formed at positions corresponding to the mounting portions (151, 152).

5. The electronic device according to claim 1, wherein a connector (6) is mounted on the circuit board, and the connector is connected to the wiring patterns (60a, 60b) of the housing via the conductive parts of the mounting portions (153, 154).

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