JP2016058453A - Wiring board, motor, electrical apparatus and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wiring board in which both high mounting position accuracy and high solder strength are satisfied in the circumferential direction.SOLUTION: A wiring board mounting an electronic component having a plurality of pins includes a plurality of footprints to which pins are soldered by reflow, and a base board on the surface of which the footprints are formed. The lead-out direction of a pin is 45 degree or less for the radial direction to the electronic component from the center of the wiring board. In the footprint, clearance in the radial direction from the center of the wiring board to the electronic component is larger than the clearance in the circumferential direction of the wiring board. The clearance in the radial direction is equal to or larger than the total of the height from the surface of the footprint to the bottom face of the pin, and the thickness of the pin.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a wiring board, an electric motor, an electric device, and an air conditioner.

  2. Description of the Related Art Conventionally, it is important to prevent misalignment when connecting pins provided in an IC (Integrated Circuit) to wiring formed on a wiring board, also called a printed circuit board, by solder.

  For example, in Patent Document 1, “in a light-emitting device that converts light having a short wavelength including ultraviolet light into visible light, the deterioration of a resin adhesive that bonds the base and the frame is suppressed, and the base and the frame are For the purpose of “providing a light emitting element storage package and a light emitting device that can prevent the light emitting characteristics of the light emitting element from being deteriorated for a long period of time”, “light containing ultraviolet light in the center of the upper surface is provided. A base 2 made of ceramics having a mounting portion 2a of a light emitting element 5 that emits light, and a metal frame 4 bonded to the outer peripheral portion of the upper surface of the base 2 so as to surround the mounting portion 2a. The body 4 is bonded to the outer peripheral side of the lower surface via an acrylic resin adhesive, and the inner peripheral side is bonded via a silicone resin adhesive.

  Further, for example, Patent Document 2 provides “providing a semiconductor device and a manufacturing method thereof that can effectively alleviate stress concentration applied to bumps and electrode pads in flip-chip mounting without incurring process complexity”. As an object, “the element electrode pad 3 for external connection disposed on the surface of the semiconductor element 2 and the substrate electrode pad 5 disposed on the surface of the wiring substrate 4 are provided, and the element electrode pad 3 and the substrate electrode pad 5 facing each other, In the semiconductor device in which the first and second electrodes are connected via the bumps 6, the first element electrode pads 3 b having an elongated shape whose length in the direction orthogonal to the radial direction is larger than the width in the radial direction from the geometric center 21 of the semiconductor element 2. And a second substrate electrode pad 5b. "A semiconductor device and a method for manufacturing the semiconductor device are disclosed.

JP 2005-183897 A JP 2009-218233 A

  However, the technique of Patent Document 1 which is the conventional technique described above is suppression of positional deviation at a level that does not cause solder failure, and is, for example, 0, like a Hall IC or Hall element that detects the rotor magnetic pole rotation position of an electric motor. There is a problem that it cannot be applied to the connection of an IC that requires a high positional accuracy of 1 mm or less.

  By the way, in the Hall IC or the Hall element that detects the rotor magnetic pole rotation position of the electric motor, the positional accuracy in the radial direction of the rotor is not required, and only the positional accuracy in the circumferential direction is required. Therefore, for example, the pin pulling direction of the Hall IC or Hall element and the radial direction of the rotor are arranged in parallel, and the circumferential clearance between the Hall IC or Hall element pin and the footprint to which the pin is connected is, for example, 0.1 mm. If it is reduced to below, the mounting position accuracy in the circumferential direction can be improved.

  In the present specification, the radial direction refers to the radial direction with reference to the rotational axis, the circumferential direction refers to the direction of drawing an arc with respect to the rotational axis, and the radial direction and the circumferential direction are orthogonal to each other. The circumferential clearance is a distance between one end of a pin connected to the footprint in the circumferential direction and one end of the footprint closer to the one end. The radial clearance is a distance between one end of a pin connected to the footprint in the radial direction and one end of the footprint closer to the one end.

  However, when the circumferential clearance is reduced in this way, the solder fillet forming region in the circumferential direction is reduced. Therefore, there has been a problem that the solder strength is reduced. In order to compensate for such a decrease in solder strength, the footprint may be enlarged in the radial direction. Patent Document 2 which is the above-described conventional technique describes that “the first element electrode pad 3b having an elongated shape whose length in the direction orthogonal to the radial direction is larger than the width in the radial direction from the geometric center 21 of the semiconductor element 2 and It is disclosed that the configuration includes the second substrate electrode pad 5b.

  However, Patent Document 2 that discloses the above conventional technique only describes that the length of the electrode pad in the direction orthogonal to the radial direction is larger than the width in the radial direction, and is orthogonal to the radial direction. Depending on the length in the direction, the required solder strength cannot be ensured.

  The present invention has been made in view of the above, and an object thereof is to obtain a wiring board that achieves both high mounting position accuracy in the circumferential direction and high solder strength.

  In order to solve the above-described problems and achieve the object, the present invention is a wiring board on which an electronic component having a plurality of pins is mounted, wherein the pins are soldered by reflow, A base substrate on which the footprint is formed, and a direction in which the pin is pulled out is 45 degrees or less with respect to a radial direction from the center of the wiring board to the electronic component. The radial clearance from the center of the wiring board to the electronic component is larger than the circumferential clearance perpendicular to the direction, and the radial clearance is from the surface of the footprint to the bottom of the pin. It is a wiring board which becomes more than the sum of the height and the thickness of the pin.

  According to the present invention, it is possible to obtain a wiring board that achieves both high mounting position accuracy and solder strength in the circumferential direction.

The figure which shows the structure of the wiring board concerning Embodiment 1. FIG. The figure which shows the IC chip mounted by soldering on the wiring board concerning Embodiment 1 The figure which shows the positional relationship of Hall IC and a rotor rotating shaft The figure which shows the upper surface of the state by which the IC chip was mounted on the wiring board concerning Embodiment 1. The figure which shows the positional relationship of the bottom face of an IC pin, and a footprint when mounting position deviation arises Sectional drawing which shows the connection state of the circumferential direction when connecting an IC pin and a footprint on the wiring board concerning Embodiment 1. Sectional drawing which shows the connection state of radial direction when connecting an IC pin and a footprint on the wiring board concerning Embodiment 1. Sectional drawing which shows the connection state of radial direction when connecting an IC pin and a footprint on the wiring board concerning Embodiment 1. The figure which shows the positional relationship of Hall IC and a rotor rotating shaft The figure which shows the electric motor concerning Embodiment 2. FIG. The figure which shows the air conditioner which is an example of the electric equipment concerning Embodiment 3.

  Hereinafter, embodiments of a wiring board, an electric motor, an electric device, and an air conditioner according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a first embodiment of a wiring board according to the present invention. 1A shows the surface on which the component is mounted, that is, the surface of the wiring board, and FIG. 1B shows the surface on which the component is not mounted, that is, the back surface of the wiring board. It is shown.

  The circular wiring board 10 has a hole 11 in the center, and includes a connector 12, a surface-mounted inverter IC 13 and Hall ICs 14a to 14c (FIG. 1A). Although not shown, wiring is formed on the base substrate 10a on which components are mounted. For example, a chip resistor or a chip capacitor may be provided, or the connector 12 and the inverter IC 13 are not provided. Also good. In the hole 11 of the wiring board 10, for example, the rotating shaft penetrates, the surface of the wiring board on which the component is mounted is disposed on the stator side, and the back surface of the wiring board on which the component is not mounted is disposed on the anti-stator side. . A wiring board is formed by mounting wiring and components on the base substrate.

  FIG. 2 is a diagram showing an IC chip mounted on the wiring board 10 shown in FIG. 1 by soldering. The IC chip shown in FIG. 2 includes an IC body 20 and IC pins 21a to 21c. The IC body 20 corresponds to the Hall ICs 14a to 14c shown in FIG. 1A, and the IC pins 21a to 21c are connected to the wiring board 10 by soldering, for example. Here, the soldering is performed by reflow. That is, reflow mounting is performed. In reflow mounting, mounting components are not fixed with an adhesive as in flow mounting, and therefore, mounting position displacement occurs due to the surface tension of the melted solder during heating in a reflow furnace.

  In this embodiment, for convenience of explanation, the IC chip includes three IC pins. However, the present invention is not limited to this, and the number of IC pins can be changed as appropriate. .

  FIG. 3 is a diagram showing the positional relationship between the Hall IC and the rotor rotation shaft that is the center of the wiring board. The IC pin pull-out direction of the Hall ICs 14A to 14C shown in FIG. 3 is parallel to the radial direction. The Hall ICs 14A to 14C correspond to the Hall ICs 14a to 14c shown in FIG. FIG. 3 exemplifies a wiring board mounted on an 8-pole 12-slot motor, and the Hall ICs are arranged at intervals of 30 degrees.

  Since the Hall ICs 14A to 14C detect the rotor magnetic pole rotation position of the electric motor, the positional accuracy in the radial direction is not required, and the positional accuracy in the circumferential direction is required. For example, the pin pull-out direction of the Hall IC or Hall element and the radial direction of the rotor are arranged in parallel, and the circumferential clearance between the Hall IC or Hall element pin and the footprint to which the pin is connected is greater than 0, for example, 0. If it is made as small as 1 mm or less, the mounting position accuracy in the circumferential direction can be improved. However, if the circumferential clearance is reduced, the solder fillet formation region is reduced, and the solder strength is reduced. Accordingly, it is conceivable to enlarge the solder fillet formation region by increasing the radial clearance.

  FIG. 4 is a view showing the top surface of the IC chip mounted on the wiring board. In FIG. 4, IC pins 21a to 21c pulled out from the IC body 20 are connected to footprints 22a to 22c. In the footprints 22a to 22c shown in FIG. 4, the radial clearance, which is the range in which the IC is shifted in the radial direction, is larger than the circumferential clearance, which is the range in which the IC is shifted in the circumferential direction. Thus, if the circumferential clearance is reduced and the radial clearance is increased, it is considered that the circumferential mounting position accuracy can be improved while suppressing a decrease in solder strength.

  FIG. 5 is a diagram showing the positional relationship between the bottom surface of the IC pin 21 and the footprint 22 when a mounting position shift occurs in the configuration shown in FIG. The IC pin 21 is a generic name for the IC pins 21a to 21c, and the footprint 22 is a generic name for the footprints 22a to 22c. As shown in FIG. 5, the mounting position deviation is particularly large when the bottom end of the IC pin 21 and the end of the footprint 22 overlap each other. Therefore, if the footprint is reduced, mounting position deviation can be suppressed, but if the footprint is simply reduced, the area where the solder fillet is formed cannot be secured, and the solder strength, that is, the bonding strength is reduced. There is a problem that it ends up.

  FIG. 6 is a cross-sectional view showing a connection state in the circumferential direction when the IC pin 21 and the footprint 22 are connected. As shown in FIGS. 6A and 6B, since the solder fillet 24 is formed in the solder fillet formation region on the footprint 22, as shown in FIG. If a wide solder fillet forming area can be secured, the solder strength can be increased. However, as described above, in the present embodiment, since the circumferential footprint 22 is reduced, the solder fillet forming region is narrowed as shown in FIG. It will end up. The reduction of the solder fillet 24 is significant when the distance from the circumferential side surface of the reduced footprint 22 to the circumferential side surface of the IC pin 21, that is, the circumferential clearance is shorter than the thickness of the IC pin 21. .

  The solder fillet preferably has an angle of 15 ° or more and 45 ° or less with a footprint which is a surface to be formed.

  Thus, when the circumferential clearance is reduced, there is a problem that the solder fillet forming region in the circumferential direction is reduced and the solder strength, that is, the bonding strength is lowered.

  FIG. 7 is a cross-sectional view showing a connection state in the radial direction when the IC pin 21 and the footprint 22 are connected. As shown in FIG. 7, the radial clearance is equal to or greater than the sum of the IC pin floating height, which is the height from the surface of the footprint 22 to the bottom surface of the IC pin 21, and the IC pin thickness. By setting the radial clearance in this way, the solder strength, that is, the bonding strength can be increased.

  FIG. 8 is another cross-sectional view showing a connection state in the radial direction when the IC pin 21 and the footprint 22 are connected. As shown in FIG. 8, the radial clearance on the opposite side of the IC body 20, which is the IC body, is the height from the surface of the footprint 22 to the bottom surface of the IC pin 21 as in FIG. 7. The sum of the height and the IC pin thickness is greater than or equal to the sum. The radial clearance on the IC body 20 side, which is the IC body, is greater than or equal to the sum of the IC pin floating height, which is the height from the surface of the footprint 22 to the bottom surface of the IC pin 21, and the IC pin body side height. As described above, it is preferable to further enlarge the radial clearance on the side of the IC body 20 which is an IC body capable of forming the solder fillet 24 high, so that the solder fillet forming region can be widened. As shown in FIG. 8, the IC pin body-side height is the height from the surface of the footprint 22 to the back surface of the IC pin 21 in a portion that is drawn from the IC body 20 and is not bent.

  As described above, according to the present embodiment, the solder fillet forming region can be widened while reducing the clearance in the circumferential direction and realizing high mounting position accuracy in the circumferential direction, thereby ensuring the solder strength. be able to.

  By the way, when mounting in a component mounting facility where the change interval of the mounting direction of the Hall IC is 90 degrees, it is difficult to make the IC pin drawing direction of the Hall IC parallel to the radial direction. FIG. 9 is a diagram showing a positional relationship between the Hall IC and the rotor rotation shaft when mounted in a component mounting facility in which the change interval of the Hall IC mounting direction is 90 degrees. As shown in FIG. 9, when mounting in a component mounting facility where the change interval of the mounting direction of the Hall ICs 14D to 14F is 90 degrees, the angle between the IC pins in the Hall ICs 14D to 14F and the radial direction is 45 degrees. What is necessary is just to arrange | position so that it may become below. FIG. 9 illustrates a case where the angle between the IC pin pull-out direction and the radial direction is 30 degrees.

  In the present embodiment, the wiring board on which the Hall IC is mounted has been described as an example, but the present invention is not limited to this and may be other electronic components. That is, one embodiment of the present invention described in this embodiment is a wiring board on which an electronic component having a plurality of pins is mounted, and a plurality of footprints in which the pins are soldered by reflow, and a surface And a base substrate on which the footprint is formed, and a direction in which the pin is pulled out is 45 degrees or less with respect to a radial direction from the center of the wiring board to the electronic component. The radial clearance from the center of the wiring board to the electronic component is larger than the clearance, and the radial clearance is the height from the surface of the footprint to the bottom surface of the pin, and the thickness of the pin. And a wiring board that is equal to or greater than the sum of the above.

  As described above, according to the present embodiment, it is possible to suppress the mounting position deviation in the circumferential direction at the time of heating in the reflow furnace with high accuracy without reducing the solder strength. Since the mounting position shift can be suppressed with high accuracy, a reduction in yield can be suppressed.

  In the present embodiment, since the description has been made focusing on the connection between one pin and one footprint, the positional deviation in the rotation direction of the IC chip is not described, but the IC main body 20 of the IC chip has no description. Since a plurality of pins are provided, positional deviation in the rotational direction can also be suppressed.

  In the present embodiment, the Hall IC is illustrated as an example of the IC chip. However, the present invention is not limited to this, and the IC chip has a mounting displacement in the circumferential direction during reflow furnace heating. Any IC that should be suppressed with high positional accuracy may be used. In the present embodiment, an IC chip having an IC pin connected to a wiring board has been described. However, the present invention is not limited to this, and has a pin (terminal) connected to the wiring board. Any electronic component may be used.

Embodiment 2. FIG.
The wiring board described in the first embodiment is built in, for example, an electric motor. FIG. 10 is a cross-sectional view showing the configuration of the electric motor according to the present embodiment. The motor shown in FIG. 10 includes a wiring board 10, a rotating shaft 30, an output side bearing 31, a counter output side bearing 32, a rotor sensor magnet 33, a rotor 34, a rotor magnet 35, and a winding terminal. The brushless DC motor includes 36, an insulator 37, a stator core 38, a winding 39, a bracket 40, a mold resin 41, and a mold stator 42.

  The wiring board 10 includes a connector 12, an inverter IC 13, and a Hall IC 14. The Hall IC 14 detects the position of the rotor 34. The wiring board 10 is arranged perpendicular to the axial direction of the rotary shaft 30 between the output side bearing 31 and the stator, and is fixed to the insulator 37. The insulator 37 electrically insulates the stator core 38 and the winding 39 from each other. The stator core 38 is formed of laminated electromagnetic steel plates. The winding 39 is wound around each slot of the stator core 38 via the insulator 37, and is connected to the inverter IC 13 of the wiring board 10 via the winding terminal 36. On the wiring board 10, a connector 12 having a lead wire connected to the control circuit is disposed. The mold stator 42 has a configuration in which the stator and the wiring board 10 are integrally molded with a mold resin 41, and a concave portion formed to accommodate the rotor 34 is provided therein. When the stator and the wiring board 10 are integrally molded with the mold resin 41 as described above, the thermal expansion coefficient differs between the mold resin 41 and the solder, and a large thermal stress is applied to the solder, so that solder strength is particularly required. The rotor 34 includes a rotor magnet 35 disposed inside the mold stator 42 and disposed on the outer peripheral side of the rotation shaft 30 so as to face the stator core 38. The rotor sensor magnet 33 for detecting the position of the Hall IC 14 is disposed in a rotor 34 with the rotation shaft 30 as a circle center. The rotor magnet 35 is a permanent magnet, for example, a ferrite magnet or a rare earth magnet. One end of the rotary shaft 30 has an output-side bearing 31 that rotatably supports the rotary shaft 30, and the other end has a non-output-side bearing 32 that rotatably supports the rotary shaft 30. The bracket 40 is conductive and is fitted into the inner peripheral portion of the mold stator 42 to close the opening of the concave portion of the mold stator 42, and the outer ring of the counter-output side bearing 32 is fitted inside the bracket 40. Yes.

  In the electric motor shown in FIG. 10, the stator and the wiring board 10 are integrally molded in order to improve heat dissipation and safety, and it is necessary to increase the strength of the solder connecting the wiring board 10 and the Hall IC 14. As described in the first embodiment, by maintaining the solder strength high, it is possible to prevent a failure of the motor due to the Hall IC being detached and to prevent a decrease in reliability. In the electric motor according to the present embodiment, the mounting position deviation in the circumferential direction of the Hall IC is suppressed with high accuracy, so that variation in the mounting position in the circumferential direction of the Hall IC is suppressed. As a result, the advance angle variation that greatly affects the efficiency of the motor is suppressed, and the power consumption is reduced.

Embodiment 3 FIG.
The electric motor described in Embodiment 2 can be applied to various electric devices, and an air conditioner can be exemplified as such an electric device. FIG. 11 is an external view showing a configuration of an air conditioner that is an example of the electrical apparatus according to the present invention. An air conditioner 50 illustrated in FIG. 11 includes an indoor unit 51, an outdoor unit 52, and a fan 53. The outdoor unit 52 is connected to the indoor unit 51. Although not shown, the indoor unit 51 includes an indoor unit blower, the outdoor unit 52 includes an outdoor unit blower, and the indoor unit blower and the outdoor unit blower are the drive sources in the second embodiment. Provided with the electric motor described above.

  By applying the electric motor of the second embodiment to the indoor unit blower and the outdoor unit blower of the present embodiment, it is possible to prevent failure of the electric motor and prevent a decrease in reliability. Failure of the blower for the outdoor unit can be prevented, and deterioration of reliability can be prevented.

  In addition, the electric motor demonstrated in Embodiment 2 is not limited to the blower for indoor units and the blower for outdoor units, For example, you may mount in a ventilation fan, household appliances, and a machine tool. By applying the electric motor of the second embodiment, it is possible to prevent a failure of the motor and prevent a decrease in reliability, to prevent a failure of the ventilation fan, home appliance, and machine tool, and to prevent a decrease in reliability. Can do.

  DESCRIPTION OF SYMBOLS 10 Wiring board, 10a Base board, 11 hole, 12 Connector, 13 Inverter IC, 14, 14a-14c, 14A-14C, 14D-14F Hall IC, 20 IC main body, 21, 21a-21c IC pin, 22, 22a- 22c Footprint, 24 Solder fillet, 30 Rotating shaft, 31 Output side bearing, 32 Counter output side bearing, 33 Rotor sensor magnet, 34 Rotor, 35 Rotor magnet, 36 Winding terminal, 37 Insulator, 38 Stator core , 39 Winding, 40 Bracket, 41 Mold resin, 42 Mold stator, 50 Air conditioner, 51 Indoor unit, 52 Outdoor unit, 53 Fan.

Claims (7)

A wiring board on which electronic components having a plurality of pins are mounted,
A plurality of footprints to which the pins are soldered by reflow; and
A base substrate on which the footprint is formed, and
The pin pull-out direction is 45 degrees or less with respect to the radial direction from the center of the wiring board to the electronic component,
In the footprint, the radial clearance from the center of the wiring board to the electronic component is larger than the circumferential clearance of the wiring board, and the radial clearance extends from the surface of the footprint to the pin. The wiring board which becomes more than the sum total of the height to the bottom face and the thickness of the pin.   The radial clearance on the main body side of the electronic component is not less than the sum of the pin floating height, which is the height from the surface of the footprint to the bottom surface of the pin, and the pin body side height. Wiring board.   The wiring board according to claim 1, wherein a drawing direction of the pin is parallel to the radial direction. A wiring board according to any one of claims 1 to 3,
An electric motor in which the base substrate is circular and the center of the wiring board is a rotating shaft.   The electric motor according to claim 4, wherein the stator and the wiring board are integrally formed of resin.   An electric device comprising the electric motor according to claim 4.   The air conditioner which is an electric equipment of Claim 6.

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