JP6681006B2 - Speaker mounting structure and mounting method - Google Patents

Description

  The present invention relates to a mounting structure and a mounting method for a speaker mounted on a substrate.

  In Patent Document 1, as a speaker mounting structure, a speaker is installed so that a sound emission hole of the speaker and a sound emission hole of the case face each other, and a ring-shaped cushion is arranged between the speaker and the case. A structure is disclosed. According to this, since the cushion fills the gap between the speaker and the case, the sound wave generated from the sound emission hole of the speaker does not escape from the sound emission hole of the case but leaks into the case from the gap between the speaker and the case. It prevents it from being lost.

JP, 2004-304420, A

  By the way, when mounting the speaker on the board, in order to improve the sound pressure of the sound emitted from the sound emission hole formed on the surface of the speaker (the surface opposite to the surface mounted on the board), It is necessary to separate the sound emitted from the back surface of the speaker (the surface mounted on the board). Since these sounds are in opposite phase, if these sounds are mixed, the sounds in opposite phases cancel each other out, causing a decrease in sound pressure.

  In order to separate sounds emitted from both sides of the speaker, a mounting structure in which a sound emitting hole portion is provided so as to project from the back surface of the speaker and the sound emitting hole portion is inserted into a hole formed in the substrate can be considered. In this mounting structure, the sound emitted from the front surface of the speaker and the sound emitted from the back surface are separated by the substrate.

  However, the sound emitted from the sound emission hole portion formed on the back surface of the speaker leaks to the side where the speaker is mounted from the gap between the sound emission hole portion and the inner surface of the hole of the board, and is emitted from the speaker surface. There is a problem that the sound pressure of the generated sound is reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a speaker mounting structure and a speaker mounting method capable of improving the sound pressure of a speaker mounted on a substrate.

The mounting structure of the speaker of the present invention is
A substrate (32) having a hole (32c) formed therein;
A speaker (1) mounted on the board, wherein a surface of the speaker mounted on the board is a back surface (22) and a surface opposite to the surface is a front surface (21). In addition to having sound emitting holes (23, 24), a sound emitting hole portion (25) which is a portion of the back surface where the sound emitting hole is formed is formed so as to project, and the sound emitting hole portion is formed in the hole. A speaker provided to be plugged in,
A shield portion (5) provided in a gap between the sound output hole portion and the inner surface of the hole;
Equipped with
The inner surface of the hole is made of metal,
The shielding portion is made of solder .

The speaker mounting method of the present invention is
A first land (32e) on which solder for connecting to the terminal (26) of the speaker (1) is provided is formed on the surface (32b), and a hole (32c) whose inner surface is covered with a metal is formed; A first step of providing solder on the first land and the second land of the substrate (32) having the second land (32d) formed on the surface (32a) around the hole;
The surface (22) of the speaker mounted on the substrate is the speaker back surface, and the opposite surface (21) is the speaker surface, and the speaker surface and the speaker back surface each have sound emission holes (23, 24). At the same time, a sound emitting hole portion (25), which is a portion where the sound emitting hole is formed on the back surface of the speaker, is formed to project, and the sound emitting hole portion is inserted into the hole after the first step. And a second step of disposing the speaker on the surface of the substrate on which the first land is formed,
After the second step, the solder provided in the first step is heated to connect the terminal of the speaker to the substrate by the solder provided in the first land, and to the second land. A third step of pouring the provided solder (5) so as to function as a shielding portion for a gap between the sound emitting hole portion and the inner surface of the hole;
It is characterized by including.

  According to the speaker mounting structure of the present invention, since the shielding portion is provided in the gap between the sound output hole portion on the back surface of the speaker and the inner surface of the hole of the substrate, the sound emitted from the sound output hole portion is emitted from the gap to the speaker. It is possible to suppress leakage to the mounted area. Thereby, the sound pressure of the speaker can be improved.

  Further, according to the speaker mounting method of the present invention, the bonding between the speaker and the substrate and the shielding of the gap between the sound output hole portion and the inner surface of the hole of the substrate can be achieved by soldering.

It is the perspective view which looked at the speaker from the surface side. It is the perspective view which looked at the speaker from the back side. It is sectional drawing of the mounting structure of a speaker. It is an enlarged view of the A section of FIG. It is the figure which looked at the part where a speaker is mounted of a printed circuit board from the 1st surface side of a circuit board. It is an exploded perspective view of a measuring instrument for vehicles. It is the figure which looked at the whole printed circuit board from the 2nd surface side of a circuit board.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The speaker 1 shown in FIGS. 1 and 2 is a device that vibrates a diaphragm according to an input electric signal and generates a sound wave according to the vibration of the diaphragm. The speaker 1 is composed of a resin housing 2 that forms the outer shape of the speaker 1, a diaphragm disposed inside the housing 2, and the like. The front surface 21 and the rear surface 22 of the housing 2 are formed with sound emission holes 23 and 24 which are holes for emitting sound waves generated by the diaphragm to the outside of the housing 2. The sound output holes 23 and 24 are holes that connect the inside and the outside of the housing 2 to each other. By providing the sound output holes 24 not only on the front surface 21 but also on the back surface 22, the space on the back side (the back surface 22 side) of the diaphragm can be expanded to the outside of the housing 2 through the sound output holes 24, whereby the diaphragm Can be easily vibrated, and high-quality sound waves can be generated.

  A protrusion 25 is formed on the back surface 22, and the sound output hole 24 is formed on the protrusion 25. Hereinafter, this protruding portion 25 is referred to as a sound output hole portion. The sound output hole portions 25 are formed at a plurality of locations (four locations in FIG. 2) on the back surface 22. Further, although FIG. 2 shows an example in which the outer peripheral shape of the sound output hole portion 25 is a substantially rectangular shape, it may be any outer peripheral shape such as a circle or a square.

  The speaker 1 is provided in the vehicle instrument 3 (see FIG. 6) and outputs, for example, a warning sound (for example, a sound that warns that the vehicle speed exceeds a predetermined high speed). The vehicle instrument 3 is arranged facing the driver's seat in an instrument panel in front of the driver's seat of the vehicle. The vehicle instrument 3 is a device that displays various vehicle information such as vehicle speed and engine speed. As shown in FIG. 6, the vehicle instrument 3 includes a lower case 31, a printed circuit board 32, an upper case 33, a prism 34, a dial 35, a dial plate 36, and a transparent cover 37 from the back side.

  As shown in FIG. 3, a sound emitting hole 31 a for emitting the sound 6 emitted from the surface 21 of the speaker 1 to the outside of the vehicle instrument 3 is formed in a portion of the lower case 31 facing the speaker 1. The sound 6 emitted from the sound emitting hole 31a is the sound heard by the vehicle occupant. The sound 7 emitted from the sound output hole 24 of the back surface 22 of the speaker 1 has a phase opposite to that of the sound 6 emitted from the front surface 21 of the speaker 1 and should be prevented from being heard by the vehicle occupant as much as possible. There is. For this reason, the space from the printed board 32 to the transparent cover 37 of the vehicle instrument 3 does not have a hole for releasing the sound 7 emitted from the sound emitting hole 24 to the outside, that is, this It has a structure that confines sound 7 in this space.

  On the printed circuit board 32, various electrically operated components provided in the vehicle instrument 3 are mounted. Specifically, an LED (not shown) that supplies light to the dial 35 and the pointer 38 is mounted on the surface 32a of the printed board 32 on the dial 35 side (see FIG. 3, hereinafter referred to as the first surface). . On the other hand, as shown in FIG. 7, on the surface 32b (hereinafter referred to as the second surface) of the printed circuit board 32 on the side of the lower case 31, for example, a stepper motor 41 for driving the pointer 38 shown in FIG. A vehicle connector 42 for connecting a communication line and a power supply line to the device (ECU, sensor, etc.) and a CPU 43 for controlling the vehicle instrument 3 are mounted. The speaker 1 is mounted on the second surface 32b of the printed board 32. Details of the mounting structure of the speaker 1 will be described later. The printed circuit board 32 is supported by the lower case 31 and the upper case 33 so as to be sandwiched between them.

  The upper case 33 is formed of a resin having a light shielding property such as PP (polypropylene) resin or ABS resin, and plays a role of a reflector that prevents light from the LED mounted on the printed circuit board 32 from leaking to the outside. ing.

  The prism 34 is formed of a light guide such as acrylic, and light from an LED mounted on the printed board 32 is incident on the prism 34 and guides the light to a light emitting portion such as a dial 35 and a pointer 38.

  The dial 35 is a plate having a base material formed of a transparent resin such as polycarbonate and a light-shielding print layer printed with a light-shielding material on the front surface or the back surface of the base material. The dial 35 is a portion that constitutes the display unit of the vehicle instrument 3. Specifically, on the surface of the dial plate 35, an index composed of a numerical value such as a vehicle speed and an engine speed and a scale is displayed in an arc shape. The light-shielding print layer is not formed in the portion where this index is displayed. Thereby, the index constitutes a light emitting portion capable of emitting light from the LED.

  A pointer 38 is arranged on the surface of the dial 35. The pointer 38 indicates the index displayed on the dial plate 35 to display the current vehicle speed, the number of engines, and the like. Further, the pointer 38 has a light emitting portion formed of a light guide such as acrylic, and can emit light when light from the LED is incident on the light emitting portion.

  The dial plate 36 is formed with a circular opening, and the dial 35 and the pointer 38 are arranged in this opening. The driver of the vehicle can visually recognize the display by the dial plate 35 and the pointer 38 through the opening of the dial plate 36 and the transparent cover 37. The vehicle instrument 3 is provided with a liquid crystal panel 39 and a backlight 40 for supplying light to the liquid crystal panel 39, which enables display of vehicle information other than vehicle speed and engine speed. The CPU 43 of FIG. 7 acquires a measured value such as the vehicle speed or the engine speed from the sensor, and rotates the stepper motor 41 so that the pointer 38 indicates an index indicating the measured value. The CPU 43 also controls the LED and the speaker 1.

  Next, a mounting structure of the speaker 1 will be described. As described above, the speaker 1 is mounted on the second surface 32b of the printed board 32. The example of FIG. 7 shows an example in which the rectangular printed board 32 is mounted on the left end side. The speaker 1 is mounted on the second surface 32b as a surface mount device (SMD). More specifically, the second surface 32b is provided with a land 32e (see FIG. 5) provided with solder for connecting to the terminal 26 (see FIG. 2) of the speaker 1. The land 32e is formed of a metal (for example, copper) to which solder can be fixed. The lands 32e are formed at four locations corresponding to the four corners of the back surface 22 of the speaker 1. The land 32e corresponds to the first land of the present invention.

  On the other hand, as shown in FIG. 2, on the back surface 22 of the speaker 1, terminals 26 connected to the lands 32e of the printed board 32 are formed. The terminals 26 are formed, for example, at the four corners of the back surface 22. The terminal 26 is formed of a metal to which solder can be fixed. Two of the four terminals 26 are set as signal input terminals that have a role of fixing the speaker 1 to the rear surface 22 and a role of receiving an electric signal for vibrating the diaphragm of the speaker 1 from the outside. ing. This signal input terminal is a terminal for electrically connecting the speaker 1 and the outside. The remaining two terminals 26 are dummy terminals that only play a role of fixing the speaker 1 to the back surface 22.

  The speaker 1 is mounted in such a manner that the terminals 26 are placed on the lands 32e and the lands 32e and the terminals 26 are connected by soldering. At this time, the front surface 21 of the speaker 1 faces the sound output hole 31 a formed in the lower case 31. The back surface 22 of the speaker 1 faces the second surface 32b of the printed circuit board 32.

  Further, the speaker 1 is mounted such that the sound emitted from the sound emitting hole 23 on the front surface 21 and the sound emitted from the sound emitting hole 24 on the back surface 22 are separated by the printed board 32. Specifically, as shown in FIG. 5, a hole 32c is formed in the printed circuit board 32 at a position corresponding to the sound output hole portion 25 of the speaker 1. The holes 32c are formed at four locations corresponding to the sound output hole portions 25. The hole 32c is a through hole that penetrates between the first surface 32a and the second surface 32b of the printed board 32. The hole 32c is formed in a shape (rectangular in the example of FIG. 5) similar to the outer peripheral shape of the sound emitting hole portion 25, and has a diameter slightly larger than that of the sound emitting hole portion 25. The hole 32c is formed as a through hole. That is, the inner surface of the hole 32c is coated (that is, plated) with a metal such as copper, so that electricity can be conducted and solder can be fixed. Note that, in FIG. 5, the illustration of the sound output hole portion 25 inserted into the hole 32c is omitted.

  As shown in FIG. 3, the sound output hole portion 25 is inserted into the hole 32c. At this time, the outlet of the sound output hole 24 may be located inside the hole 32c, may be located on the same plane as the first surface 32a of the printed circuit board 32, or from the first surface 32a. It may be located at a protruding position. FIG. 3 shows an example in which the outlet of the sound output hole 24 is located at a position flush with the first surface 32a of the printed board 32 of the vehicle instrument 3. Instead of the example of FIG. 3, for example, by projecting the outlet of the sound output hole 24 from the first surface 32a, the solder 5 (see FIG. 4) enters the sound output hole 24 during reflow to be described later. Can be suppressed.

  Further, as shown in FIG. 4, in the gap between the inner surface of the hole 32c and the sound output hole portion 25, the solder 5 that functions as a shielding portion that shields the gap is provided. As shown in FIG. 5, a land 32d for providing the solder 5 in the hole 32c is formed around the hole 32c of the printed circuit board 32. The land 32d is provided on the first surface 32a so as to come into contact with the opening edge of the hole 32c on the first surface 32a side. FIG. 5 shows an example in which the land 32d is formed so as to surround the entire circumference of the hole 32c. According to this, the solder 5 can be provided on the entire circumference of the gap between the inner surface of the hole 32c and the sound output hole portion 25. The land 32d may be provided only in a part around the hole 32c.

  In addition, in FIG. 5, although the land 32d formed around one hole 32c is illustrated and the land formed around the remaining hole 32c is omitted, in actuality, around the remaining hole 32c. The land is also formed. The land 32d is formed of a metal (for example, copper) to which solder can be fixed. The land 32d corresponds to the second land of the present invention.

  Next, a process of mounting the speaker 1 on the printed board 32 will be described. First, the printed circuit board 32 having the above-described lands 32d and 32e and the hole 32c is prepared. Next, solder is applied to each of the lands 32d and 32e. The solder coating step corresponds to the first step of the present invention. Next, the speaker 1 is mounted (arranged) on the second surface 32b of the printed board 32 so that each terminal 26 rides on each land 32e and the sound emission hole portion 25 is inserted into the hole 32c. This mounting step corresponds to the second step of the present invention.

  Next, reflow is performed on the printed circuit board 32 on which the speaker 1 is mounted. That is, the solder applied to each land 32d, 32e is heated to connect the land 32e and the terminal 26 of the speaker 1 by solder. Further, by performing the reflow, as shown in FIG. 4, the solder 5 applied to the land 32d on the first surface 32a melts and flows into the hole 32c as a through hole connected to the land 32d. Then, the solder 5 is fixed to the metal inner surface of the hole 32c inside the hole 32c. This reflow process corresponds to the third process of the present invention.

  As described above, according to the present embodiment, the gap between the inner surface of the hole 32c and the sound output hole portion 25 can be filled with the solder 5, so that the sound 7 emitted from the back surface 22 of the speaker 1 is output from the gap to the printed circuit board. The sound 6 emitted from the surface 21 of the speaker 1 may leak to the area of the printed circuit board 32 on the side of the first surface 32a, or conversely, the sound 6 emitted from the surface 21 of the speaker 1 may leak to the area of the printed circuit board 32 on the side of the first surface 32a. Can be suppressed. This can prevent the sound pressure of the sound 6 from the surface 21 from decreasing.

  Further, since the step (reflow) for pouring the solder 5 into the hole 32c and the step (reflow) for connecting the terminal 26 of the speaker 1 to the land 32e of the printed circuit board 32 can be performed in the same step, the mounting of the speaker 1 It is possible to prevent the process from becoming complicated.

  Further, since the speaker 1 is mounted on the main board 32 (board on which the CPU 43, the stepper motor 41, etc. are mounted) of the vehicle instrument 3, compared to a case where it is mounted on a board different from the main board 32, It is possible to prevent the structure of the vehicle instrument 3 from becoming complicated.

  It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the claims. For example, by attaching a metal terminal to the outer surface of the sound output hole portion 25, the outer surface may be made of metal. According to this, since the solder can be fixed to the outer surface of the sound emitting hole portion 25, the gap between the sound emitting hole portion 25 and the inner surface of the hole 32c can be more easily filled with the solder.

  In the above embodiment, the SMD type speaker 1 is taken as an example, but the present invention is applied to an insertion mounting type speaker in which lead terminals connected to the speaker are passed through holes in the board and soldered on one side or both sides. May be.

  Further, the speaker 1 may be mounted on the first surface 32a of the printed board 32. Alternatively, a board may be provided separately from the main board 32 of the vehicle instrument 3, and the speaker 1 may be mounted on this separate board.

  The land 32d may be formed on the second surface 32b in addition to or instead of the first surface 32a. By forming the lands 32d on both the first surface 32a and the second surface 32b and pouring the solder into the holes 32c from both sides, the gap between the sound emitting hole portion 25 and the inner surface of the holes 32c is further filled with the solder. It can be made easier.

  Further, the shielding portion that shields the gap between the sound output hole portion and the inner surface of the hole of the substrate is not limited to solder, and if it has a shielding function, for example, a resin ring having a shape along the planar shape of the gap is used. Of course, it may be pressed into the gap to form a shield. In this case, the holes in the substrate do not have to be through holes.

  Further, the present invention may be applied to a board-mounted speaker used in a device other than the vehicle instrument 3.

DESCRIPTION OF SYMBOLS 1 speaker 21 front surface of speaker 22 back surface of speaker 23, 24 sound emission hole 25 sound emission hole portion on back surface of speaker 32 printed circuit board 32a first surface of printed circuit board 32b second surface of printed circuit board 32c hole of printed circuit board 32d, 32e Land 5 Solder

Claims (6)

A substrate (32) having a hole (32c) formed therein;
A speaker (1) mounted on the board, wherein a surface of the speaker mounted on the board is a back surface (22) and a surface opposite to the surface is a front surface (21). In addition to having sound emitting holes (23, 24), a sound emitting hole portion (25) which is a portion of the back surface where the sound emitting hole is formed is formed so as to project, and the sound emitting hole portion is formed in the hole. A speaker provided to be plugged in,
A shield portion (5) provided in a gap between the sound output hole portion and the inner surface of the hole;
Equipped with
The inner surface of the hole is made of metal,
A mounting structure for a speaker, wherein the shielding portion is solder . The speaker mounting structure according to claim 1 , wherein an outer surface of the sound output hole portion is formed of metal. The mounting structure for a speaker according to claim 1 or 2 , wherein the mounting structure is provided in a vehicle instrument (3). A first land (32e) on which solder for connecting to the terminal (26) of the speaker (1) is provided is formed on the surface (32b), and a hole (32c) whose inner surface is covered with a metal is formed, A first step of providing solder on the first land and the second land of the substrate (32) having the second land (32d) formed on the surface (32a) around the hole;
The surface (22) of the speaker mounted on the substrate is the speaker back surface, and the opposite surface (21) is the speaker surface, and the speaker surface and the speaker back surface each have sound emission holes (23, 24). At the same time, a sound emitting hole portion (25), which is a portion where the sound emitting hole is formed on the back surface of the speaker, is formed to project, and the sound emitting hole portion is inserted into the hole after the first step. And a second step of disposing the speaker on the surface of the substrate on which the first land is formed,
After the second step, the solder provided in the first step is heated to connect the terminal of the speaker to the substrate by the solder provided in the first land, and to the second land. A third step of pouring the provided solder (5) so as to function as a shielding portion for a gap between the sound output hole portion and the inner surface of the hole;
A method for mounting a speaker, comprising: The speaker mounting method according to claim 4 , wherein an outer surface of the sound output hole portion is formed of metal. The speaker mounting method according to claim 4 or 5 , wherein the board and the speaker are provided in a vehicle instrument (3).