JP7272237B2 - electronic controller - Google Patents

Description

The present invention relates to an electronic control device including a circuit board, a connector connected to the circuit board, and electronic components mounted on the surface of the circuit board.

2. Description of the Related Art An electronic control device such as an in-vehicle engine ECU includes, for example, a circuit board on which electronic components are mounted, a connector connected to the circuit board, and the like in a metal housing. In this case, for example, one side of the circuit board is provided with a region to which a connector is connected, and this region is provided with a plurality of through holes for connecting connector pins. Then, with the plurality of connector pins of the connector inserted into the through holes, soldering is performed by flow soldering on the back side of the circuit board, that is, on the side opposite to the connector mounting surface ( For example, see Patent Document 1).

JP-A-2002-280717

By the way, many of the electronic components mounted on the circuit board as described above are surface-mounted components. The mounting density is increased by mounting at positions. On the other hand, as described above, flow soldering is used to connect connector pins to a circuit board. In this flow soldering, the temperature of the molten solder is raised to shorten the immersion time and thus the working time. is being attempted.

However, if the temperature of the molten solder during flow soldering is increased in this way, the high-temperature heat of the solder will be transferred to the surface-mounted components already mounted in the connector connection area on the surface side of the circuit board, causing adverse effects. There is a concern that At present, even if the temperature of surface-mounted components rises, it is desired to keep the temperature below the guaranteed temperature.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an electronic control device in which electronic components are mounted in a connector connection area of a circuit board, and which can suppress temperature rise of the electronic components. to provide.

The electronic control device of the present invention includes a circuit board (31, 51, 61, 71), a connector (4) connected to the circuit board, and an electronic component (6) mounted on the surface of the circuit board. wherein the circuit board has a connector connection area (A) including an area to which connector pins (8) of the connector are connected, and at least one of the electronic components is within the connector connection area and the circuit board is provided with a solder resist layer and corresponds to the electronic component (6A) mounted at least in the connector connection area of the back surface of the circuit board In some areas, the solder resist layer (33, 54, 63, 74) is thicker than in other areas.

In the above configuration, the solder resist layer is formed thicker than the other regions in at least the portions of the back surface of the circuit board corresponding to the electronic components mounted in the connector connection regions. Since the solder resist acts as a heat resistance, the thick solder resist layer increases the heat resistance of that portion. Heat transfer to the electronics in the area can be reduced. As a result, when an electronic component is mounted on the connector connection area of the circuit board, it is possible to suppress the temperature rise of the electronic component.

Moreover, in the above configuration, three means are employed to suppress heat transfer to the electronic components in the connector connection area on the surface side of the circuit board. That is, the first means for increasing the heat capacity of the portion by providing the dummy component is to place the inner layer conductor pattern of the circuit board in a detached state where it does not exist at the position corresponding to the electronic component in the connector connection area. As a second means for reducing the thermal conductivity of this portion, the solder resist layer in the portion corresponding to the electronic parts in the connector connection area of the circuit board is provided thicker than the other portions to increase the thermal resistance of that portion. This is the third means. Any two of these three means may be combined, or all three may be combined.

1 is a longitudinal front view showing a first embodiment and schematically showing the configuration of a circuit board; FIG. top view of circuit board Enlarged bottom view of dummy parts Vertical front view of electronic control unit Schematic diagram of flow soldering Vertical front view of a circuit board showing a second embodiment Vertical front view of a circuit board showing a third embodiment Vertical front view of a circuit board showing a fourth embodiment Vertical front view of a circuit board showing a fifth embodiment Vertical front view of a circuit board showing a sixth embodiment Vertical front view of a circuit board showing a seventh embodiment

Hereinafter, several embodiments applied to an in-vehicle engine ECU (Electronic Control Unit) will be described with reference to the drawings. Parts common to a plurality of embodiments are denoted by the same reference numerals, and detailed descriptions and new illustrations are omitted. In addition, although FIG. 1 and the like are cross-sectional views showing the circuit board in longitudinal section, hatching is omitted as necessary for easier understanding.

(1) First Embodiment A first embodiment will be described with reference to FIGS. 1 to 5. FIG. FIG. 4 schematically shows the overall configuration of the electronic control unit 1 according to this embodiment. This electronic control unit 1 is constructed by accommodating a circuit board 3 in a housing 2 which is thin in the vertical direction and has a substantially rectangular box shape in the figure. Along with this, a connector 4 for connection with the outside is provided on the left side wall portion of the housing 2 in the figure. The housing 2 is constructed by butting and joining a thin rectangular box-shaped case 2a having an opening at the bottom and a cover 2b closing the opening at the bottom. The case 2a and the cover 2b are made of metal such as aluminum or iron.

Here, the configurations of the circuit board 3 and the connector 4 will be described with reference to FIGS. 1 to 3 as well. As shown in FIG. 1, the circuit board 3 has ICs, diodes, capacitors, resistors, etc. on both sides of a multilayer wiring board 5, ie, a first surface 5a (upper surface in the figure) and a second surface 5b (lower surface in the figure). A control circuit or the like is configured by mounting a plurality of electronic components 6 . A chip-type surface-mounted component is used as the electronic component 6, and is connected to lands on the first surface 5a and the second surface 5b of the multilayer wiring board 5 by reflow soldering, for example. In the drawing, the soldered portion of the electronic component 6 is the solder connection portion 7 . Although not shown in detail, both surfaces of the multilayer wiring board 5 are covered with a solder resist except for land portions.

As shown in FIG. 2, the connector 4 includes a connector housing 4a made of an insulating material and a plurality of connector pins 8. The connector 4 is provided on the left side of the multilayer wiring board 5 in the drawing. It is provided extending in the front-rear direction along. At this time, although not shown in detail, the connector 4 is divided into a plurality of blocks in the front-rear direction in the figure. Although omitted, a plurality of through holes to which the connector pins 8 are connected are provided vertically through the multilayer wiring board 5 in the left region of the multilayer wiring board 5 .

The connector housing 4 a is attached to the left end of the first surface 5 a of the multilayer wiring board 5 . Each connector pin 8 is inserted into a plurality of through holes of the multilayer wiring board 5 from the side of the first surface 5a and protrudes to the side of the second surface 5b. As will be described later, the tip of each connector pin 8 is soldered to the second surface 5b by flow soldering. In this embodiment, the connector connection area A is the area where the connector pins 8 are connected, that is, the area where the through holes are formed.

Now, in the circuit board 3, as shown in FIGS. is implemented. In order to distinguish this electronic component from other electronic components 6, it will be referred to as an electronic component directly below the connector 6A. In this embodiment, as shown in FIGS. 3 and 5, on the circuit board 3, a surface mount component is positioned on the back side of the electronic component 6A directly below the connector mounted in the connector connection area A. A dummy component 9 made of is mounted.

The dummy component 9 is composed of, for example, a chip-type 0Ω resistor. In this case, as shown in FIG. 3, a wiring pattern 10 is formed on the second surface 5b of the multilayer wiring board 5 on the back side of the electronic component 6A directly below the connector. A resist opening B not coated with a solder resist is formed in a portion of the second surface 5b of the multilayer wiring board 5 where the dummy component 9 is to be mounted, and the wiring pattern 10 is exposed. The dummy component 9 is connected to the exposed portion of the wiring pattern 10 by a solder connection portion 7 . The wiring pattern 10 may constitute a circuit, or may be independent and not electrically connected to other parts.

Next, the process of mounting components on the circuit board 3 having the above configuration will be briefly described with reference to FIG. In assembling the circuit board 3, the electronic components 6 including the electronic components 6A directly below the connector are mounted on the first surface 5a and the second surface 5b of the multilayer wiring board 5, respectively. This mounting includes the steps of applying solder paste to the lands, temporarily fixing the electronic component 6 and the electronic component 6A immediately below the connector to the first surface 5a and the second surface 5b of the multilayer wiring board 5, and reflow soldering. Each electronic component 6 including the electronic component 6</b>A immediately below the connector is mounted on the multilayer wiring board 5 by the solder connection portion 7 . At this time, when the electronic component 6 is mounted on the second surface 5b of the multilayer wiring board 5, the dummy component 9 is also mounted.

After the electronic components 6 and the like are mounted on the multilayer wiring board 5, the connector 4 is mounted. Flow soldering is employed for this implementation. In this flow soldering, as schematically shown in FIG. 5, in a solder tank in which molten solder is stored, a molten solder jet S is provided in which the molten solder is blown upward by driving a pump. On the other hand, in the multilayer wiring board 5, the connector 4 is temporarily held in a state in which each connector pin 8 is inserted into each through hole. In this state, the multilayer wiring board 5 is passed through the second surface 5b, that is, the lower surface in FIG. done.

According to such a first embodiment, the following functions and effects can be obtained. That is, in the electronic control device 1 of the present embodiment, the dummy component 9 is mounted on the circuit board 3 on the back side of the electronic component 6A directly below the connector mounted in the connector connection area A. Due to the configuration in which the dummy component 9 is mounted, the circuit board 3 has a large heat capacity in the portion where the electronic component 6A directly below the connector is mounted. Therefore, heat transfer from the second surface 5b side of the circuit board 3 to the electronic component 6A directly below the connector in the connector connection area A on the first surface 5a side during flow soldering when connecting the connector 4 can be suppressed.

As a result, according to the electronic control device 1 of the first embodiment, the electronic component 6A directly below the connector is mounted in the connector connection area A of the circuit board 3, and the temperature rise of the electronic component 6A directly below the connector is suppressed. There is an excellent effect that it can be done. As a result, even if the temperature of molten solder in flow soldering is increased, adverse effects on the electronic component 6A immediately below the connector can be prevented, and the immersion time can be shortened to improve work efficiency. By mounting the electronic components 6A directly under the connector in the connector connection area A, it is of course possible to improve the mounting density of the circuit board 3. FIG.

(2) Second Embodiment Next, a second embodiment will be described with reference to FIG. The second embodiment differs from the first embodiment in the configuration of the circuit board 21 . That is, this circuit board 21 has a plurality of electronic components 6 mounted on both sides of a multilayer wiring board 22, ie, a first surface 22a (upper surface in the figure) and a second surface 22b (lower surface in the figure). The connector 4 is mounted on the surface 22a, and the electronic component 6A directly below the connector is mounted on the connector connecting area A. As shown in FIG.

At this time, the multilayer wiring board 22 is configured by alternately laminating insulating layers and inner layer conductor patterns. ) is provided at a position away from the position corresponding to the electronic component 6A mounted in the connector connection area A. FIG. That is, the GND inner layer pattern 23 is omitted in the portion directly below the electronic component 6A directly below the connector. The dummy component 9 is not mounted on the portion of the second surface 22b of the multilayer wiring board 22 that corresponds to the back side of the connector connection area A. As shown in FIG. Moreover, the resist opening B does not exist, and the whole is covered with the resist except for the land of the through hole.

Even in the circuit board 21 having the above configuration, as in the first embodiment, the first surface 22a and the second surface 22b of the multilayer wiring board 22 are provided with the electronic components 6 including the electronic components 6A immediately below the connector. Mounting is done using reflow soldering. After that, the connector 4 is mounted using flow soldering. In the present embodiment, the inner-layer GND pattern 23 as an inner-layer conductor pattern provided on the circuit board 21 is in a detached state where it does not exist at a position corresponding to the electronic component 6A directly below the connector mounted in the connector connection area A. ing.

Since this inner layer GND pattern 23 has better thermal conductivity than the insulating material forming the multilayer wiring board 22, the inner layer GND pattern 23 is less thermally conductive than other parts where Therefore, heat transfer from the back side of the circuit board 21 to the electronic component 6A directly below the connector in the connector connection area A on the front side can be suppressed during flow soldering.

As a result, in the second embodiment, as in the first embodiment, the electronic component 6A directly below the connector is mounted on the connector connecting area A of the circuit board 21, and the electronic component 6A directly below the connector is mounted. It has an excellent effect of being able to suppress the temperature rise of. In addition, in the present embodiment, the inner layer GND pattern 23 has a higher degree of freedom in which part of the circuit board 21 and in which path it is provided than other inner layer conductor patterns. can be easily installed. In this embodiment, since additional parts such as the dummy parts 9 are not required, the manufacturing cost can be reduced accordingly.

(3) Third Embodiment Next, a third embodiment will be described with reference to FIG. The third embodiment differs from the first embodiment in the configuration of the circuit board 31 . That is, this circuit board 31 has a plurality of electronic components 6 mounted on both sides of a multilayer wiring board 32, ie, a first surface 32a (upper surface in the figure) and a second surface 32b (lower surface in the figure). The connector 4 is mounted on the surface 32a, and the electronic component 6A directly below the connector is mounted on the connector connecting area A. As shown in FIG.

At this time, solder resist is applied to both surfaces of the multilayer wiring board 32 except for the land portion to form a solder resist layer (not shown as a whole). A portion of the surface 32b corresponding to the electronic component 6A directly below the connector mounted in the connector connection area A is provided with a thick solder resist layer 33, which is thicker than the other areas. To give a specific example, the thickness dimension of the solder resist layer is, for example, 40 μm, while the thickness dimension of the thick solder resist layer 33 is, for example, 80 μm, which is approximately double the thickness.

In the circuit board 31 having the above configuration, the solder resist layer is thicker than the other regions in the second surface 32b of the circuit board 31 corresponding to the electronic components 6A directly below the connector mounted in the connector connection region A. A thick solder resist layer 33 is provided. Since the solder-resist layer has a thermal resistance, the provision of the thick solder-resist layer 33 having a thickness larger than that of other portions increases the thermal resistance of that portion. Therefore, heat transfer from the back side of the circuit board 31 to the electronic component 6A directly below the connector in the connector connection area A on the front side can be suppressed during flow soldering.

As a result, according to the third embodiment, as in the first and second embodiments, the electronic component 6A directly below the connector is mounted on the connector connection area A of the circuit board 31, and the connector This provides an excellent effect of suppressing the temperature rise of the directly-lowered electronic component 6A. Further, in the present embodiment, it is possible to achieve a simple configuration by only increasing the thickness dimension of a portion of the solder resist layers on the second surface 32b of the multilayer wiring board 32. FIG. In the third embodiment, only the portion of the solder resist layer corresponding to the electronic component 6A directly below the connector is made thick. In (1), the solder resist layer can be made thick.

(4) Fourth to Seventh Embodiments and Other Embodiments FIGS. 8, 9, 10 and 11 show the fourth, fifth, sixth and seventh embodiments, respectively. , hereinafter, these embodiments will be described in order. Here, in the above-described first embodiment, the heat capacity of this portion is increased by providing the dummy component 9 as means for suppressing the temperature rise of the electronic component 6A immediately below the connector. This is called the first means.

As a means for suppressing the temperature rise of the electronic component 6A directly below the connector, in the second embodiment, the inner layer GND pattern 23 of the circuit board 21 is placed in a missing state that does not exist at a position corresponding to the electronic component 6A directly below the connector. By doing so, the thermal conductivity of this portion is reduced. This is called a second means. In the third embodiment, the thick solder resist layer 33 is provided on the portion of the circuit board 31 corresponding to the electronic component 6A directly below the connector, thereby increasing the thermal resistance of this portion. This is called a third means.

FIG. 8 shows the configuration of a circuit board 41 according to the fourth embodiment. He is trying to combine said 1st means and 2nd means in this 4th Embodiment. That is, the circuit board 41 has a plurality of electronic components 6 mounted on both sides of the multilayer wiring board 42, that is, the first surface 42a (upper surface in the figure) and the second surface 42b (lower surface in the figure). The connector 4 is mounted on 42a, and the electronic component 6A directly below the connector is mounted on the connector connecting area A. As shown in FIG.

On the second surface 42b of the circuit board 41, a dummy component 9, which is a surface-mounted component, is mounted on the back side of the electronic component 6A directly below the connector. Along with this, the inner-layer GND pattern 43 as an inner-layer conductor pattern provided on the circuit board 41 is in a missing state where it does not exist at a position corresponding to the electronic component 6A directly below the connector mounted in the connector connection area A. . According to the fourth embodiment as described above, when the electronic component 6A directly below the connector is mounted in the connector connection area A of the circuit board 41, the temperature rise of the electronic component 6A directly below the connector can be suppressed. It works great.

FIG. 9 shows the configuration of a circuit board 51 according to the fifth embodiment. He is trying to combine said 2nd means and 3rd means in this 5th Embodiment. That is, the circuit board 51 has a plurality of electronic components 6 mounted on both sides of the multilayer wiring board 52, ie, the first surface 52a (upper surface in the figure) and the second surface 52b (lower surface in the figure). The connector 4 is mounted on 52a, and the electronic component 6A directly below the connector is mounted on the connector connecting area A. As shown in FIG.

An inner-layer GND pattern 53 as an inner-layer conductor pattern provided on the circuit board 51 is not present at a position corresponding to the electronic component 6A directly below the connector mounted in the connector connection area A and is in a missing state. . Along with this, a thick solder-resist layer is formed in a portion of the second surface 52b of the circuit board 51 corresponding to the electronic component 6A directly below the connector mounted in the connector connection region A, which is thicker than the other regions. 54 are provided. According to the fifth embodiment, in the case where the electronic component 6A directly below the connector is mounted in the connector connection area A of the circuit board 51, it is possible to suppress the temperature rise of the electronic component 6A directly below the connector. It works great.

FIG. 10 shows the configuration of a circuit board 61 according to the sixth embodiment. He is trying to combine said 1st means and 3rd means in this 6th Embodiment. That is, the circuit board 61 has a plurality of electronic components 6 mounted on both sides of the multilayer wiring board 62, that is, the first surface 62a (upper surface in the figure) and the second surface 62b (lower surface in the figure). The connector 4 is mounted on 62a, and the electronic component 6A directly below the connector is mounted on the connector connecting area A. As shown in FIG.

On the second surface 62b of the circuit board 61, a dummy component 9, which is a surface-mounted component, is mounted on the back side of the electronic component 6A directly below the connector. Along with this, a thick solder-resist layer is formed in a portion of the second surface 62b of the circuit board 61 corresponding to the electronic component 6A directly below the connector mounted in the connector connection region A, which is thicker than the other regions. 63 are provided. According to the sixth embodiment, in the case where the electronic component 6A directly below the connector is mounted in the connector connection area A of the circuit board 61, it is possible to suppress the temperature rise of the electronic component 6A directly below the connector. It works great.

FIG. 11 shows the configuration of a circuit board 71 according to the seventh embodiment. In this seventh embodiment, the above first means, second means . He is trying to combine three of the third means. That is, the circuit board 71 has a plurality of electronic components 6 mounted on both sides of the multilayer wiring board 72, that is, the first surface 72a (upper surface in the figure) and the second surface 72b (lower surface in the figure). The connector 4 is mounted on 62a, and the electronic component 6A directly below the connector is mounted on the connector connecting area A. As shown in FIG.

On the second surface 72b of the circuit board 71, a dummy component 9, which is a surface-mounted component, is mounted on the back side of the electronic component 6A directly below the connector. Along with this, the inner-layer GND pattern 73 as an inner-layer conductor pattern provided on the circuit board 71 is in a missing state not existing at a position corresponding to the electronic component 6A directly below the connector mounted in the connector connection area A. . Furthermore, a thick solder-resist layer 74, which is thicker than the other regions, is applied to a portion of the second surface 72b of the circuit board 71 corresponding to the electronic component 6A directly under the connector mounted in the connector connection region A. is provided. According to the seventh embodiment, the electronic component 6A directly below the connector is mounted in the connector connection area A of the circuit board 71, and the temperature rise of the electronic component 6A directly below the connector can be suppressed. It works great.

In the above-described embodiment, a vehicle engine ECU is given as a specific example of an electronic control device, but the present invention can be applied to electronic control devices in general in which a circuit board and a connector are arranged in a housing. In each of the above-described embodiments, one electronic component 6A directly below the connector is mounted in the connector connection area A, but it is of course applicable to mounting a plurality of electronic components. In addition, in the second, fourth, fifth and seventh embodiments, the inner layer GND pattern as the inner layer conductor pattern has been described. Similar action and effect can be obtained by providing it at a deviated position. Various modifications are also possible for the process of mounting components on the circuit board.

Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to such examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations, including single elements, more, or less, are within the scope and spirit of this disclosure.

In the drawings, 1 is an electronic control unit, 2 is a housing, 3, 21, 31, 41, 51, 61, 71 are circuit boards, 4 are connectors, 5, 22, 32, 42, 52, 62, 72 are multilayers. Wiring board, 5a, 22a, 32a, 42a, 52a, 62a, 72a are first surfaces, 5b, 22b, 32b, 42b, 52b, 62b, 72b are second surfaces, 6 are electronic components, and 6A are electronic components directly below connectors , 8 is a connector pin, 9 is a dummy part, 23, 43, 53, 73 are inner layer GND patterns (inner layer conductor patterns), 33, 54, 63, 74 are thick solder resist layers, A is a connector connection area, S is a Figure 2 shows a jet of molten solder;

Claims (6)

An electronic control device comprising a circuit board (31, 51, 61, 71), a connector (4) connected to the circuit board, and an electronic component (6) mounted on the surface of the circuit board,
The circuit board has a connector connection area (A) including an area to which connector pins (8) of the connector are connected, and at least one of the electronic components is positioned and mounted within the connector connection area. Along with being
The circuit board is provided with a solder resist layer, and at least a portion of the back surface of the circuit board corresponding to the electronic component (6A) mounted in the connector connection area is covered with the solder resist layer (33 , 54, 63, 74) are thicker than other areas. An electronic control device comprising a circuit board (41), a connector (4) connected to the circuit board, and electronic components (6) mounted on the surface of the circuit board,
The circuit board has a connector connection area (A) including an area to which connector pins (8) of the connector are connected, and at least one of the electronic components is positioned and mounted within the connector connection area. Along with being
A dummy component (9) is mounted on the circuit board so as to be located on the back side of the electronic component (6A) mounted in the connector connection area,
An electronic control device, wherein an inner layer conductor pattern (43) is provided on the circuit board at a position away from a position corresponding to the electronic component mounted in the connector connection area. An electronic control device comprising a circuit board (51), a connector (4) connected to the circuit board, and electronic components (6) mounted on the surface of the circuit board,
The circuit board has a connector connection area (A) including an area to which connector pins (8) of the connector are connected, and at least one of the electronic components is positioned and mounted within the connector connection area. Along with being
In the circuit board, an inner layer conductor pattern (53) is provided at a position deviated from a position corresponding to the electronic component (6A) mounted in the connector connection area,
The circuit board is provided with a solder-resist layer, and the solder-resist layer (54) is formed on at least a portion of the back surface of the circuit board corresponding to the electronic component mounted in the connector connection area. electronic control unit that is thicker than the area of An electronic control device comprising a circuit board (61), a connector (4) connected to the circuit board, and electronic components (6) mounted on the surface of the circuit board,
The circuit board has a connector connection area (A) including an area to which connector pins (8) of the connector are connected, and at least one of the electronic components is positioned and mounted within the connector connection area. Along with being
A dummy component (9) is mounted on the circuit board so as to be located on the back side of the electronic component (6A) mounted in the connector connection area,
A solder resist layer is provided on the circuit board, and the solder resist layer (63) is formed on at least a portion of the back surface of the circuit board corresponding to the electronic component mounted on the connector connection area. electronic control unit that is thicker than the area of An electronic control device comprising a circuit board (71), a connector (4) connected to the circuit board, and electronic components (6) mounted on the surface of the circuit board,
The circuit board has a connector connection area (A) including an area to which connector pins (8) of the connector are connected, and at least one of the electronic components is positioned and mounted within the connector connection area. Along with being
A dummy component (9) is mounted on the circuit board so as to be located on the back side of the electronic component (6A) mounted in the connector connection area,
An inner layer conductor pattern (73) is provided on the circuit board at a position away from a position corresponding to the electronic component mounted in the connector connection area,
The circuit board is provided with a solder-resist layer, and the solder-resist layer (74) is formed on at least a portion of the back surface of the circuit board corresponding to the electronic component mounted in the connector connection area. electronic control unit that is thicker than the area of The electronic control device according to any one of claims 2, 3 and 5 , wherein the inner layer conductor pattern is an inner layer GND pattern ( 43 , 53, 73).

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