JP7123236B2 - circuit board - Google Patents

Description

The present invention relates to a circuit board on which chip ceramic capacitors are mounted.

Conventionally, circuit boards on which chip ceramic capacitors are mounted have been widely used. A ceramic capacitor is a capacitor that uses a ceramic material as a dielectric, and is generally used for noise suppression, voltage stabilization, signal frequency filtering, and the like. A chip ceramic capacitor is a ceramic capacitor formed into a rectangular parallelepiped chip shape. A chip ceramic capacitor has electrodes at both ends, and the electrodes are connected to lands on a circuit board by soldering.

Generally, chip ceramic capacitors are electronic components that are prone to cracking when distorted, and if cracks occur, they fail in a short-circuit or open-circuit state. When the circuit board is divided into multiple pieces, when the circuit board is attached to the product, or when the housing is inserted into or removed from the connector mounted on the circuit board, if the circuit board is distorted, the chips mounted on the circuit board may be damaged. Distortion may also occur in ceramic capacitors and cracks may occur in chip ceramic capacitors.

Therefore, in order to prevent cracks from occurring in the chip ceramic capacitor, it is preferable to avoid mounting the chip ceramic capacitor near the end surface of the circuit board. Therefore, when mounting a chip ceramic capacitor on a circuit board, it is common to mount the chip ceramic capacitor on the inner side of the circuit board as much as possible. In other words, there is a substantial limit to the placement area of the chip ceramic capacitors on the circuit board.

Moreover, in order to reduce the distortion that occurs in the circuit board when dividing the circuit board into multiple pieces, a dedicated dividing jig is sometimes used. However, when a dedicated dividing jig is used, it may not be possible to mount components relatively taller than other components in the vicinity of the end face of the circuit board due to structural constraints of the jig.

Further, Patent Document 1 discloses a circuit board in which electronic components are mounted on the substrate, and a strip-shaped adhesive layer is provided on the substrate along at least a part of the peripheral edge of the electronic components. there is

JP 2010-212542 A

However, according to the circuit board of Patent Document 1, the band-shaped adhesive layer cannot function as part of the circuit board. For this reason, the band-like adhesive layer restricts the board design of the circuit board, and makes the design of the circuit board even more difficult while there are restrictions on noise countermeasures, insulation distance, and the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit board capable of alleviating restrictions on the arrangement area of chip ceramic capacitors and improving the degree of freedom in board design.

In order to solve the above-described problems and achieve the object, a circuit board according to the present invention includes a printed wiring board and a chip ceramic capacitor mounted on the printed wiring board. The circuit board is mounted with reinforcing parts having relatively higher rigidity than the printed wiring board in the plane of the circuit board. The reinforcing component is arranged within a range of a predetermined separation distance from the peripheral edge portion of the chip ceramic capacitor on the side facing the reinforcing component within the plane of the circuit board.

Advantageous Effects of Invention The circuit board according to the present invention is effective in that it is possible to relax restrictions on the arrangement area of chip ceramic capacitors and improve the degree of freedom in board design.

1 is a plan view showing the main configuration of a circuit board according to Embodiment 1 of the present invention; FIG. FIG. 2 is a cross-sectional view of the main parts of the circuit board shown in FIG. 1, and is a cross-sectional view of the main parts along the chip ceramic capacitor in the circuit board; FIG. 2 is a cross-sectional view of the main parts of the circuit board shown in FIG. 1, and is a cross-sectional view of the main parts along the metal plate; FIG. 2 is a cross-sectional view of main parts showing the main configuration of another circuit board according to the first embodiment of the present invention; FIG. 2 is a perspective view showing the main configuration of another circuit board according to the first embodiment of the present invention; FIG. 2 is a perspective view showing the main configuration of another circuit board according to the first embodiment of the present invention;

A circuit board according to an embodiment of the present invention will be described in detail below with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1.
FIG. 1 is a plan view showing the main configuration of a circuit board 1 according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the circuit board 1 shown in FIG. 1 and is a cross-sectional view of the circuit board 1 taken along the chip ceramic capacitor 2 . FIG. 2 shows a cross section along the longitudinal direction of the external shape of the chip ceramic capacitor 2 in the plane of the circuit board 1 . FIG. 3 is a cross-sectional view of the circuit board 1 shown in FIG. 1 and a cross-sectional view along the metal plate 6. As shown in FIG.

The circuit board 1 according to the first embodiment is built in an electric/electronic device and operates by being supplied with power from a commercial power source or a power source such as a battery. The circuit board 1 supplies power to various devices such as various actuators and various sensors connected to the circuit board 1, and transmits and receives electrical signals to and from the various devices, thereby driving the various devices. That is, the circuit board 1 is a component generally having a plate shape, which is a control board provided to realize the functions of the electric/electronic device.

A circuit board 1 according to the first embodiment is a circuit board in which electronic components are soldered to a printed wiring board 11 to form an electronic circuit. The printed wiring board 11 has a known structure, and includes wiring patterns 13 on one side and the other side of the insulating substrate 12, a solder resist layer 14 which is an insulating layer laminated on the surface of the insulating substrate 12, and terminals of electronic components. is provided with a land 5 to which is connected.

That is, the circuit board 1 includes a surface of an insulating substrate 12 made of a resin plate made of glass epoxy or a resin plate made of paper phenol, and solder resist layers 14 laminated on the surface of the insulating substrate 12 and solder resist layers 14. A wiring pattern 13 is formed on the . The wiring pattern 13 is made of foil of a metal having relatively low electrical resistivity among metals such as copper and aluminum. In addition to the circuit board having a plate shape, there is also a circuit board called a flexible board that is made bendable by using a thin film-like resin.

The circuit board 1 has electronic parts such as a chip ceramic capacitor 2 , an integrated circuit 3 and a board-mounted connector 4 mounted on one surface 11 a of a printed wiring board 11 . The electronic component is fixed to the metal foil lands 5 of the wiring pattern 13 exposed on the surface without the solder resist layer 14 laminated thereon by using a method such as soldering. The circuit board 1 also includes electronic components such as transistors, connectors, and fuses, but they are omitted here.

As shown in FIG. 1, the circuit board 1 has a plurality of chip ceramic capacitors 2 mounted along the peripheral edge portion 1a of the circuit board 1 in the in-plane direction. That is, the circuit board 1 has three chip ceramic capacitors 2 mounted along the periphery of the printed wiring board 11 as shown in FIG. The chip ceramic capacitor 2 is mounted in a state in which the longitudinal direction of the outer shape in the plane of the circuit board 1 is parallel to the extending direction of the peripheral edge portion 1a of the circuit board.

As shown in FIG. 2, the chip ceramic capacitor 2 is mounted across two electrically insulated lands 5 and electrically connected to the two lands 5 . Chip ceramic capacitor 2 is soldered and connected to land 5 with solder 7 . The solder 7 is an alloy containing tin as a main component, which is used to join the electronic component and the printed wiring board 11 by utilizing its low melting point.

The chip ceramic capacitor 2 is a ceramic capacitor that uses a ceramic material as a dielectric and is formed into a chip shape. is responsible for

Further, the circuit board 1 has a metal plate on the surface of the region between the chip ceramic capacitor 2 and the peripheral edge portion 1a of the circuit board along the longitudinal direction of the external shape of the chip ceramic capacitor 2 in the plane of the circuit board 1. 6 are placed. Here, in the circuit board 1 having a rectangular outer shape in the plane of the circuit board 1, the peripheral edge portion 1a of the circuit board is the closest to the chip ceramic capacitor 2 among the two sides facing each other across the chip ceramic capacitor 2. It is the peripheral edge of the circuit board located on the side. The metal plate 6 is arranged in the plane of the circuit board 1 with its longitudinal direction along the plane of the circuit board 1 within a predetermined distance from the periphery of the chip ceramic capacitor 2 . . The peripheral portion of the chip ceramic capacitor 2 here is the peripheral portion of the chip ceramic capacitor 2 on the side facing the metal plate 6 in the plane of the circuit board 1 .

The metal plate 6 is a plate-shaped reinforcing component that reinforces the rigidity of the circuit board 1 and is made of a material having relatively higher rigidity than the printed wiring board 11 . In the circuit board 1, a metal plate 6 made of a material having electrical conductivity, relatively low electrical resistivity among metals, and relatively higher rigidity than the printed wiring board 11 is used as a reinforcing component. ing. Metal plate 6 is made of copper, for example. The metal plate 6 is connected by soldering to the wiring pattern 13 arranged in the region between the chip ceramic capacitor 2 and the peripheral edge portion 1a of the circuit board at both ends in the longitudinal direction.

As shown in FIG. 3, the wiring pattern 13 arranged in the region between the chip ceramic capacitor 2 and the peripheral portion 1a of the circuit board is partially cut off. The wiring pattern 13 is exposed from the solder resist layer 14 in pattern end regions 13 a and pattern end regions 13 b , which are regions on the side of the cut ends.

The metal plate 6 is fixed to the pattern end region 13a and the pattern end region 13b by soldering. That is, the metal plate 6 is arranged by electrically connecting two cut ends of the wiring pattern 13 exposed from the solder resist layer 14 . The metal plate 6 arranged in this manner has a function as a substitute for the wiring pattern 13 in the region where the wiring pattern 13 is divided. That is, the metal plate 6, which is a reinforcing component having conductivity, has a function as a part of the wiring pattern 13 and can be used as the wiring pattern 13, so that the degree of freedom in designing the circuit board 1 is improved. can be made

In addition, the metal plate 6, which has relatively higher rigidity than the printed wiring board 11, is arranged within the plane of the circuit board 1 within a predetermined distance from the periphery of the chip ceramic capacitor 2. , the rigidity of the area around the metal plate 6 in the plane of the circuit board 1 can be increased, and the bending strength of the area around the metal plate 6 and the bending strength of the circuit board 1 as a whole can be improved. That is, the area around the metal plate 6 on the circuit board 1 is less likely to be distorted.

As a result, when manufacturing the circuit board 1, for example, when dividing a plurality of circuit boards, when attaching the circuit board to a product, and when inserting or removing the housing from a connector mounted on the circuit board, the circuit board 1 can be It is possible to suppress the occurrence of cracks in the chip ceramic capacitor 2 even when the chip ceramic capacitor 2 is distorted. That is, since the metal plate 6 is arranged within a range of a predetermined distance from the peripheral edge of the chip ceramic capacitor 2 in the plane of the circuit board 1, any damage to the circuit board 1 may occur during the manufacture of the circuit board 1 or the like. It is possible to suppress cracks in the chip ceramic capacitor 2 due to strain in the chip ceramic capacitor 2 caused by the strain.

The separation distance may be appropriately determined in consideration of the rigidity of the printed wiring board 11 and the rigidity of the metal plate 6 so as to suppress cracks in the chip ceramic capacitor 2 . Moreover, the material of the metal plate 6 and the thickness and width of the metal plate 6 may be appropriately determined depending on conditions such as the rigidity of the printed wiring board 11 so as to suppress the occurrence of cracks in the chip ceramic capacitor 2 .

Also, the metal plate 6 is preferably arranged in the region between the chip ceramic capacitor 2 and the peripheral portion 1a of the circuit board. The metal plate 6 is arranged in a region between the chip ceramic capacitor 2 and the peripheral edge portion 1a of the circuit board, thereby increasing the rigidity of the region around the peripheral edge portion 1a of the circuit board, which is likely to be bent, and increasing the rigidity of the circuit board. It is possible to improve the bending strength of the area around the peripheral edge portion 1a and the bending strength of the circuit board 1 as a whole. As a result, the occurrence of cracks in the chip ceramic capacitors 2 disposed inside the metal plate 6 in the plane of the circuit board 1 can be more reliably suppressed during the manufacture of the circuit board 1 described above.

Even if the metal plate 6 is arranged on the in-plane surface of the circuit board 1 on the side opposite to the peripheral edge portion 1a of the circuit board with the chip ceramic capacitor 2 interposed therebetween, the above-mentioned chip ceramic capacitor 2 is prevented from being cracked. effect to be obtained.

In FIG. 1, one long metal plate 6 is arranged along the longitudinal direction of the outer shapes of the plurality of chip ceramic capacitors 2 in the region between the chip ceramic capacitors 2 and the peripheral edge portion 1a of the circuit board. ing. However, the metal plate 6 may be divided between the chip ceramic capacitor 2 and the peripheral edge portion 1a of the circuit board as long as cracks in the chip ceramic capacitor 2 can be suppressed.

FIG. 4 is a fragmentary cross-sectional view showing the main configuration of another circuit board 21 according to Embodiment 1 of the present invention. Another circuit board 21 shown in FIG. 4 is different from the circuit board 1 described above in that a metal plate 6 is mounted on the surface of the other surface 11 b of the printed wiring board 11 .

The metal plate 6 is arranged on the other surface 11 b of the printed wiring board 11 in a region corresponding to the chip ceramic capacitor 2 within the plane of the circuit board 1 . That is, the chip ceramic capacitor 2 is arranged on the other surface 11 b of the printed wiring board 11 within a predetermined distance from the periphery of the chip ceramic capacitor 2 within the plane of the circuit board 1 . The metal plate 6 is fixed by soldering to a pattern end region 13c and a pattern end region 13d, which are regions on the side of the cut ends of the wiring pattern 13 arranged on the other surface 11b of the printed wiring board 11. It is

The other circuit board 21 configured in this way can obtain the same effect as the circuit board 1 described above.

In the above description, the metal plate 6 is arranged on the surface of the other surface 11 b of the printed wiring board 11 in the area corresponding to the chip ceramic capacitor 2 within the plane of the circuit board 1 . If the metal plate 6 is arranged on the other surface 11b of the printed wiring board 11 within a predetermined distance from the peripheral edge of the chip ceramic capacitor 2 in the plane of the circuit board 1, the above-described circuit board An effect similar to that of 1 can be obtained.

For example, on the other surface 11b of the printed wiring board 11, the metal plate 6 divides the wiring pattern 13 arranged in the area between the chip ceramic capacitor 2 and the peripheral edge portion 1a of the circuit board 1 in the plane of the circuit board 1. It may be fixed by soldering to the two end regions which are joined together. In this case as well, the metal plate 6 is arranged within a predetermined distance from the periphery of the chip ceramic capacitor 2 in the plane of the circuit board 1, so that the same effects as those of the circuit board 1 described above can be obtained. be done.

FIG. 5 is a perspective view showing the main configuration of another circuit board 31 according to the first embodiment of the invention. Another circuit board 31 basically has the same configuration as the circuit board 1 described above. The other circuit board 31 uses a heat sink 8 as a reinforcing component that reinforces the rigidity of the circuit board 1 .

As shown in FIG. 5, in another circuit board 31, a heat sink 8, which is a fin-shaped reinforcing component, is mounted in an area adjacent to the chip ceramic capacitor 2 mounted on the one surface 11a of the printed wiring board 11. As shown in FIG. The heat sink 8 is arranged on the surface of the printed wiring board 11 so as to surround the periphery of the semiconductor element 9 which is an electronic component mounted on the one surface 11 a of the printed wiring board 11 . has a function of efficiently radiating heat to cool the semiconductor element 9 .

The heat sink 8 is arranged within a predetermined distance from the periphery of the chip ceramic capacitor 2 in the plane of the circuit board 1 .

The separation distance may be appropriately determined in consideration of the rigidity of the printed wiring board 11 and the rigidity of the heat sink 8 so as to suppress cracks in the chip ceramic capacitor 2 . Also, the material of the heat sink 8 and the dimensions and shape of the heat sink 8 are appropriately determined so as to suppress the occurrence of cracks in the chip ceramic capacitor 2 depending on conditions such as the heat generation characteristics of the semiconductor element 9 and the rigidity of the printed wiring board 11. Just do it.

In the other circuit board 31 configured in this manner, the heat sink 8 having relatively higher rigidity than the printed wiring board 11 is spaced from the periphery of the chip ceramic capacitor 2 in the plane of the circuit board 1 by a predetermined distance. By being arranged within the range of the distance, the rigidity of the area around the heat sink 8 in the plane of the circuit board 1 is increased, and the bending strength of the area around the heat sink 8 and the bending strength of the circuit board 1 as a whole are improved. becomes possible.

As in the case of the circuit board 1 described above, when the circuit board 1 is manufactured, a plurality of circuit boards are divided, when the circuit boards are attached to a product, and when a connector mounted on the circuit board is attached to the housing. Even when the circuit board 1 is distorted when inserting or removing the chip ceramic capacitor 2, cracks in the chip ceramic capacitor 2 can be suppressed. That is, since the heat sink 8 is arranged within a range of a predetermined distance from the peripheral edge of the chip ceramic capacitor 2 in the plane of the circuit board 1, the heat sink 8 caused in the circuit board 1 at the time of manufacturing the circuit board 1, etc. It is possible to suppress the occurrence of cracks in the chip ceramic capacitor 2 due to the strain in the chip ceramic capacitor 2 caused by the strain.

That is, in the other circuit board 31 as well, in the same way as in the circuit board 1 described above, cracks in the chip ceramic capacitor 2 caused by the distortion occurring in the circuit board 1 can be suppressed.

Also, the heat sink 8 may be mounted on the surface of the other surface 11b of the printed wiring board 11 in the same manner as the other circuit board 21 shown in FIG. In this case as well, the heat sink 8 is arranged within a predetermined distance from the periphery of the chip ceramic capacitor 2 in the plane of the circuit board 1, so that the same effect as the other circuit board 31 described above can be obtained. can get.

FIG. 6 is a perspective view showing the main configuration of another circuit board 41 according to the first embodiment of the invention. Another circuit board 41 basically has the same configuration as the circuit board 1 described above. In the other circuit board 41, solder 42, which is a conductive metal material, is used as a reinforcing component for reinforcing the rigidity of the circuit board 1. As shown in FIG.

As shown in FIG. 6, in the other circuit board 41, of the wiring patterns 13 formed on the one surface 11a of the printed wiring board 11, the wiring patterns 13 positioned around the chip ceramic capacitor 2 are covered with the solder resist layer . It is exposed from the solder resist layer 14 without breaking. Solder 42 is piled up on the wiring pattern 13 exposed from the solder resist layer 14 .

The wiring pattern 13 exposed from the solder resist layer 14 is arranged within a predetermined distance from the peripheral edge of the chip ceramic capacitor 2 within the surface of the circuit board 1 .

The clearance may be appropriately determined in consideration of the rigidity of the printed wiring board 11 so as to suppress cracks in the chip ceramic capacitor 2 . Also, the material of the solder 42, the amount of the solder 42, and the shape of the solder 42 may be appropriately determined depending on conditions such as the rigidity of the printed wiring board 11 so as to suppress cracks in the chip ceramic capacitor 2. .

In the other circuit board 41 constructed in this manner, the solder 42 having relatively higher rigidity than the printed wiring board 11 is spaced from the peripheral edge of the chip ceramic capacitor 2 within the plane of the circuit board 1 by a predetermined distance. By being arranged within the range of the distance, the rigidity of the region around the solder 42 in the plane of the circuit board 1 is increased, and the bending strength of the region around the solder 42 and the bending strength of the circuit board 1 as a whole are improved. becomes possible.

As in the case of the circuit board 1 described above, when the circuit board 1 is manufactured, a plurality of circuit boards are divided, when the circuit boards are attached to a product, and when a connector mounted on the circuit board is attached to the housing. Even when the circuit board 1 is distorted when inserting or removing the chip ceramic capacitor 2, cracks in the chip ceramic capacitor 2 can be suppressed. That is, since the solder 42 is arranged within a range of a predetermined distance from the peripheral edge of the chip ceramic capacitor 2 in the plane of the circuit board 1, the solder 42 is formed on the circuit board 1 during the manufacturing of the circuit board 1. It is possible to suppress the occurrence of cracks in the chip ceramic capacitor 2 due to the strain in the chip ceramic capacitor 2 caused by the strain.

That is, in the other circuit board 41 as well, in the same way as in the circuit board 1 described above, cracks in the chip ceramic capacitors 2 caused by the distortion occurring in the circuit board 1 can be suppressed.

In the other circuit board 41, since the solder 42 is arranged on the wiring pattern 13 arranged around the chip ceramic capacitor 2 in the plane of the circuit board 1, the arrangement of other circuit configurations is not disturbed. , the solder 42 can be easily arranged, and the reinforcement component does not restrict the board design of the other circuit board 41 .

Moreover, since the solder 42 has conductivity, even if it is arranged on the wiring pattern 13 exposed from the solder resist layer 14 , the function of the wiring pattern 13 is not hindered. The solder 42 , which is a conductive reinforcing component, functions as a part of the wiring pattern 13 and can be used as the wiring pattern 13 .

Also, the solder 42 may be mounted on the other surface 11b of the printed wiring board 11 in the same manner as the other circuit board 21 shown in FIG. In this case also, the solder 42 is arranged on the wiring pattern 13 arranged within the range of the predetermined separation distance from the periphery of the chip ceramic capacitor 2 in the plane of the circuit board 1, so that the above-mentioned other An effect similar to that of the circuit board 41 can be obtained.

As described above, each of the reinforcing parts has a function of reinforcing the rigidity of the circuit board as well as a function of one of the component parts of the circuit board. That is, in the circuit board 1, the other circuit board 21, the other circuit board 31, and the other circuit board 41 described above, the reinforcing components are all within a predetermined distance range from the periphery of the chip ceramic capacitor 2. The wiring pattern 13 or the semiconductor element 9 arranged inside constitutes a part of the components of the circuit board, or utilizes the components of the circuit board itself. As a result, the reinforcing component does not restrict the design of the circuit board, and does not limit the position of the chip ceramic capacitor 2 on the circuit board. can suppress the occurrence of cracks.

In addition, since it is possible to take measures to prevent cracks from occurring in the chip ceramic capacitor 2 with the above-mentioned reinforcing parts, tall parts such as the chip ceramic capacitor 2 mounted on the circuit board, a choke coil and a transformer (not shown) can be used in the circuit. Separation from the end face of the substrate is no longer essential, and the options for preventing the occurrence of cracks in the chip ceramic capacitor 2 are increased. In addition, since there are many options for preventing cracks in the chip ceramic capacitor 2, the degree of freedom in designing the circuit board increases.

That is, for example, even if a special dividing jig is used to reduce the distortion that occurs in the circuit board when dividing the circuit board into a plurality of pieces, the edge surface of the circuit board can be divided without being subject to the structural restrictions of the jig. It becomes possible to mount relatively tall components in the vicinity.

Therefore, according to the first embodiment, it is possible to relax restrictions on the arrangement area of the chip ceramic capacitor 2 on the circuit board and improve the degree of freedom in designing the circuit board.

The configurations shown in the above embodiments show an example of the content of the present invention, and the techniques of the embodiments can be combined with each other, or can be combined with another known technique. However, part of the configuration may be omitted or changed without departing from the gist of the present invention.

Reference Signs List 1 circuit board 1a peripheral edge of circuit board 2 chip ceramic capacitor 3 integrated circuit 4 board mounting connector 5 land 6 metal plate 7, 42 solder 8 heat sink 9 semiconductor element 11 printed wiring board 11a One surface 11b Other surface 12 Insulating substrate 13 Wiring pattern 13a, 13b, 13c, 13d Pattern end region 14 Solder resist layer 21, 31, 41 Other circuit board.

Claims (5)

a printed wiring board;
a chip ceramic capacitor mounted on the printed wiring board;
A circuit board comprising
A reinforcing part having relatively higher rigidity than the printed wiring board is mounted in the plane of the circuit board,
The reinforcing component is arranged within a range of a predetermined separation distance from the peripheral edge of the chip ceramic capacitor on the side facing the reinforcing component within the plane of the circuit board. The reinforcing component is a metal plate having a function as part of the wiring pattern formed on the printed wiring board ,
The wiring pattern is partially divided,
2. The circuit board according to claim 1 , wherein said metal plate is arranged to electrically connect two cut ends of said cut wiring pattern . 3. The circuit board according to claim 2, wherein said metal plate is arranged in a region between said chip ceramic capacitor and a peripheral edge of said circuit board. The reinforcing component is a heat sink mounted on the printed wiring board ,
2. The circuit board according to claim 1 , wherein the heat sink cools an electronic component mounted on the printed wiring board, which is different from the chip ceramic capacitor . 2. The circuit board according to claim 1, wherein said reinforcing component is solder piled up on a wiring pattern arranged within a predetermined distance from the periphery of said chip ceramic capacitor on said printed wiring board.

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