U.S. patent application number 10/766166 was filed with the patent office on 2004-07-15 for vibration motor holding apparatus and portable electronic equipment having the same.
This patent application is currently assigned to Matsushita Electric Industrial Co., Ltd.. Invention is credited to Hirai, Koutarou, Satoh, Noriyoshi.
Application Number | 20040135445 10/766166 |
Document ID | / |
Family ID | 18502757 |
Filed Date | 2004-07-15 |
United States Patent
Application |
20040135445 |
Kind Code |
A1 |
Satoh, Noriyoshi ; et
al. |
July 15, 2004 |
Vibration motor holding apparatus and portable electronic equipment
having the same
Abstract
A vibration motor 18 constituted by a motor provided with a
weight 57 is covered with a cover 44 having a flat portion for
making the cover 44 be sucked easily and a marking for positioning,
and this vibration motor is mounted on a main-body printed board 9.
In this main-body printed board, line lands and main-body lands
also having a function for identification are provided outside the
outline of the mounted vibration motor, so that a displacement of
the mounting position can be easily detected even visually.
Inventors: |
Satoh, Noriyoshi; (Kanagawa,
JP) ; Hirai, Koutarou; (Kanagawa, JP) |
Correspondence
Address: |
PEARNE & GORDON LLP
1801 EAST 9TH STREET
SUITE 1200
CLEVELAND
OH
44114-3108
US
|
Assignee: |
Matsushita Electric Industrial Co.,
Ltd.
Osaka
JP
|
Family ID: |
18502757 |
Appl. No.: |
10/766166 |
Filed: |
January 28, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10766166 |
Jan 28, 2004 |
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09826632 |
Apr 5, 2001 |
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6720690 |
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09826632 |
Apr 5, 2001 |
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09472477 |
Dec 27, 1999 |
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6274955 |
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Current U.S.
Class: |
310/81 |
Current CPC
Class: |
G10K 9/13 20130101; H05K
3/303 20130101; H05K 2201/10371 20130101; H05K 2203/166 20130101;
H02K 7/063 20130101; B06B 1/04 20130101; H05K 2201/09781 20130101;
H05K 1/0269 20130101 |
Class at
Publication: |
310/081 |
International
Class: |
H02K 007/06; H02K
007/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 1998 |
JP |
10-373786 |
Claims
What is claimed is:
1. A vibrator comprising: a vibration motor having: a rotary
member; a base on which said rotary member is mounted; and a cover
provided on said base and covering said rotary member; and a
printed circuit board on which said vibration motor is mounted,
wherein said cover has a hole.
2. A method for manufacturing a vibrator, said apparatus including
a vibration motor having a rotary member, a base on which said
rotary member is mounted, and a cover provided on said base,
covering said rotary member, and having a hole; and a printed
circuit board on which said vibration motor is mounted, said method
comprising the steps of: loading said vibration motor on said
printed circuit board; and mounting said vibration motor on said
printed circuit board by using a reflow soldering.
3. An electronic equipment comprising: a vibrator including: a
vibration motor having: a rotary member; a base on which said
rotary member is mounted; and a cover provided on said base and
covering said rotary member; and a printed circuit board on which
said vibration motor is mounted, wherein said cover has a hole.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/826,632 filed on Apr. 5, 2001, which is a
divisional patent application of U.S. patent application Ser. No.
09/472,477 filed on Dec. 27, 1999, now U.S. Pat. No. 6,274,955 on
Aug. 14, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field of the Invention
[0003] The present invention relates to a vibration motor which is
used in a portable electronic equipment such as a portable
telephone, a pocket bell or the like, and which silently informs a
user of incoming etc. by vibration, and relates to a portable
electronic having the vibration motor.
[0004] 2. Description of the Related Art
[0005] JP-A-10-248203 discloses one of conventional vibration
motors used as silent information sources in miniature radio
communication equipment, in which a cored-type brushless vibration
motor is disclosed.
[0006] FIG. 6 is a sectional view of a main portion of the
cored-type brushless vibration motor.
[0007] In FIG. 6, a bearing holder portion 102 is provided at the
center of a bracket 101 forming the bottom of the vibration motor.
This bearing holder portion 102 has a catch portion 103 and an
erected portion 104 formed by cutting and erecting a part of the
bracket 101.
[0008] A sintered oilless bearing 105 is attached to the inside of
this bearing holder portion 102 through a cover plate 106, and a
stator core 109 having an armature coil 108 wound on a plurality of
salient poles 107 is attached to the outside.
[0009] A rotor 110 has a magnet holder 111 and a cylindrical magnet
113 fixed to the magnet holder 111 and having a plurality of field
poles disposed in a blade portion 112 of the stator core 109
through a radial gap. Further, the rotating body 110 is fitted by
pressing a shaft 115 into a burring hole 114 disposed at the
rotation center of the magnet 113. In addition, one end of the
shaft 115 is rotatably supported by the sintered oilless bearing
105, and the other end is rotatably supported through a similar
sintered oilless bearing by a case 116 having another function as a
cover.
[0010] In addition, a power supply method is to connect a terminal
of the coil to one side of a flexible printed board so as to drive
the motor.
[0011] However, in the above-mentioned conventional art, a usual
vibration motor is extracted by an automatic sucking machine,
automatically arranged on a board and subjected to assembling in a
normal automatic assembling/wiring process in the case where the
vibration motor is supplied by a parts maker in the packaged form
of a pallet, a reel or the like. In that case, first, the vibration
motor cannot be extracted by the automatic sucking machine if the
vibration motor has a shape similar to that as mentioned above.
That is, the automatic sucking machine sucks the ceiling of a part
pneumatically. However, the aforementioned vibration motor is not
even in the ceiling of the vibration motor because a sintered
oilless bearing for rotatably supporting a shaft lies at the center
of a cover. Therefore, even if the ceiling is sucked pneumatically
by the automatic sucking machine, the air leaks from a gap between
the shaft and the bearing so that sucking of the ceiling cannot be
performed.
[0012] Further, since the vibration motor in the conventional art
is not designed to suit a reflow soldering, special parts are
required for assembling the vibration motor into a miniature radio
communication equipment and holding the vibration motor therein,
and the work for making the above operation demands expert
employees, so that the number of labor-hour and the cost are
increased. It is therefore necessary to make the vibration motor at
least suitable for the reflow soldering so that the vibration motor
can be applied to an automatic assembling process for mass
production.
[0013] In the reflow soldering method, after parts to be mounted
are arranged on a printed board, the parts and the board are passed
through a reflow furnace so as to be connected with each other by
solder. This solder is obtained in a way such that creamy solder is
passed through an atmosphere at a high temperature to be fused and
then the fused solder is solidified after being cooled. Here, it is
necessary to pay attention to the case where solder balls
scattering in the reflow furnace adhere to a coil or a magnet in
the middle of the reflow soldering. In that case, it is necessary
to give enough consideration to such a trouble that such an
adhering solder ball blocks starting when the vibration motor
starts, or such a solder ball rubs on the coil, the magnet or the
like so as to generate irregular noise, etc.
[0014] In addition, even if the vibration motor is mounted on the
printed board, it is necessary to perform accurate or proper
positioning of the vibration motor. It is therefore necessary to
take a dimensional measurement of the mounted position of the
vibration motor. There are a large number of problems like the
above matters when the reflow soldering is performed.
[0015] That is, in order to perform the reflow soldering perfectly
so as to automate a wiring/assembling process, there has been a
problem that automation must be fulfilled in all the steps of the
following items 1 to 4 while the quality have to be also
guaranteed.
[0016] 1. To extract supplied parts by means of an automatic
sucking machine or the like.
[0017] 2. To arrange the extracted parts onto a printed board
automatically.
[0018] 3. To take measures against solder balls in a reflow
furnace.
[0019] 4. To inspect the positions of the parts after the parts are
mounted.
SUMMARY OF THE INVENTION
[0020] An object of the present invention is to provide a vibration
motor holding apparatus in which a configuration of a vibration
generating means is realized with guaranteed quality by all the
steps of extracting supplied parts, automatically arranging the
parts onto a printed board, taking measures against solder balls in
a reflow furnace, and identifying/inspecting the positions of the
parts after the parts are mounted, in order to perform reflow
soldering upon the vibration generating means together with other
electronic parts on the same printed board in a lump without using
any special parts such as elastic or inelastic holding members or
the like.
[0021] In order to achieve the above object, according to a first
aspect of the present invention, there is provided a vibration
motor holding apparatus comprising: a rotating body having a rotary
member provided on an external surface of a base, and a cover for
covering the rotary member; and a board on which the rotating body
is mounted; wherein a position identifying mark is provided on the
board in order to mount the rotating body in a predetermined
position on the board, the position identifying mark being exposed
or bared in the outside of an outline of the rotating body when the
rotating body is mounted in the predetermined position on the
board.
[0022] With this configuration, in the case where a motor such as a
cored-type brushless motor, a coreless brushless motor, a
brush-type motor, or the like, is used as a vibration motor to
function as a rotating body, when the rotating body of any type of
such motors is mounted on a printed board, automatic arrangement of
the rotating body on the printed board can be made easily by
automatically sucking the ceiling of the cover of the rotating
body. It can be confirmed from above that the identification mark
provided outside the rotating body attachment position on the board
is hidden by the rotating body if the position of the rotating body
mounted on the board is abnormal, while the mark is exposed or
bared in the outside of the rotating body when the position is
normal. It is therefore possible to easily identify, judge and
inspect whether terminals on the base on the rotating body side are
surely connected to corresponding main-body lands on the board or
not, whether the terminals are short-circuited with other lands or
not, whether the rotating body does not abut against other parts or
not, and so on.
[0023] According to a second aspect of the present invention, there
is provided a vibration motor holding apparatus comprising: a
vibration motor having a base in which terminals are formed on a
back surface or a side surface of the base, a stator in which a
coil is wound around a stator core, a magnet disposed in opposition
to the stator, and a cover provided to cover the stator and the
magnet, the stator and the magnet being disposed on a front surface
side of the base so that one of the stator and the magnet is not
rotatable relatively to the base while the other is rotatable; and
a board on which the vibration motor is mounted; wherein a position
identifying mark exposed or bared in the outside of an outline of
the vibration motor mounted in a predetermined position on the
board is provided on the board.
[0024] With this configuration, the vibration motor is constituted
by a brushless motor constituted by a stator in which a coil is
wound on a stator core, and a rotor magnet. When the vibration
motor is mounted on a printed board, the cover ceiling of the
vibration motor is sucked automatically so that it becomes easy to
arrange the vibration motor on the board automatically. It can be
confirmed from above that the identification mark provided outside
the vibration motor attachment position on the board is hidden by
the vibration motor if the position of the vibration motor mounted
on the board is abnormal, while the mark is exposed or bared in the
outside of the vibration motor if the position is normal. It is
therefore possible to easily identify, judge and inspect whether
terminals on the base on the vibration motor side are surely
connected to corresponding main-body lands on the board or not,
whether the terminals are short-circuited with other lands or not,
and so on.
[0025] According to a third aspect of the present invention, there
is provided a vibration motor holding apparatus comprising: a
rotating body having a base, a rotary member provided on a front
surface side of the base, and a cover having an electromagnetically
shielding property and provided to cover the rotary member; a board
on which the rotating body is mounted; and a shield member provided
to cover at least a part of the board; wherein the rotating body is
disposed inside the shield member.
[0026] With this configuration, noise generated from the rotating
body which may be constituted by various motors can be prevented
from leaking outside the rotating body. In addition, it may not be
necessary to provide a shield member for electromagnetically
shielding the rotating body from other parts mounted on the board.
It is therefore possible to ensure a mounting area on the printed
board as large as possible, so that it is possible to improve the
mounting efficiency.
[0027] According to a fourth aspect of the present invention, there
is provided a vibration motor holding apparatus comprising: a
vibration motor having a base in which terminals are formed on a
back surface or a side surface of the base, a stator in which a
coil is wound around a stator core, a magnet disposed in opposition
to the stator, and a cover provided to cover the stator and the
magnet, the stator and the magnet being disposed on a front surface
side of the base so that one of the stator and the magnet is not
rotatable relatively to the base while the other is rotatable; a
board on which the vibration motor is mounted; and a shield member
provided to cover parts mounted on the board; wherein the vibration
motor is disposed inside the shield member.
[0028] With this configuration, noise generated from the vibration
motor constituted by a brushless motor is prevented from leaking
outside the vibration motor. In addition, it may not be necessary
to provide a shield member for electromagnetically shielding the
vibration motor from other parts mounted on the board. It is
therefore possible to ensure a mounting area on the printed board
as large as possible, so that it is possible to improve the
mounting efficiency.
[0029] According to a fifth aspect of the present invention, in the
above vibration motor holding apparatus, an air hole is provided in
the cover so as to connect spaces inside and outside the cover to
each other.
[0030] When electronic parts, a motor, and so on constituting a
receiving circuit portion or a radio circuit portion pass through a
reflow furnace together with the main-body printed board, these
electronic parts, motor, etc. pass through an atmosphere at
150.degree. C. to 250.degree. C. for a predetermined period. At
this time, if the inside of the cover had a closed structure as in
the background art, force was generated against the internal
surface of the cover due to thermal expansion of air in the inside
of the cover so that the cover was separated from the motor printed
board. However, with the above-mentioned configuration, very small
air holes connecting the outside and the inside of the cover are
provided so that the air inside the cover can be prevented from
expanding. It is therefore possible to avoid an unexpected
situation such as the separation of the cover or the like.
[0031] According to a sixth aspect of the present invention, in the
above vibration motor holding apparatus, a portion of the cover is
made to contact against the surface of the base so as to perform
positioning of the cover in the height direction.
[0032] With this configuration, the distance between the ceiling of
the cover and the back surface of the base, that is, the height of
parts can be formed with precision if the parts are formed so that
the distances between the abutment surfaces of the parts against
the base and the ceilings of the parts do not scatter, and if the
thickness of the base is controlled. It is possible to easily
distinguish the case where the vibration motor is mounted
abnormally with foreign matters etc. interposed between the base
and the board, from the case where the vibration motor is mounted
normally.
[0033] According to a seventh aspect of the present invention, in
the above vibration motor holding apparatus, at least one of the
mark, marking on the top surface of the cover, shapes of the base
and the cover, and a fillet formed outside the base is used for
positioning the vibration motor.
[0034] With this configuration, it is possible to accurately detect
a displacement in the vibration motor mounting position in a
two-dimensional direction (the planar direction of the board).
[0035] According to an eighth aspect of the present invention, in
the above vibration motor holding apparatus, the cover is
electrically connected to the board.
[0036] With this configuration, it is possible to ground the
cover.
[0037] According to a ninth aspect of the present invention, in the
above vibration motor holding apparatus, the mark is a grounding
pattern.
[0038] With this configuration, if the mark for position
identification is a grounding pattern, it may not be necessary to
screen-print solder on the mark. It is therefore possible to make
the mark function as an identification mark because the state of
the surface of the mark does not change even after mounting.
[0039] According to a tenth aspect of the present invention, there
is provided a portable electronic equipment provided with a
vibration motor holding apparatus according to any one of the first
to ninth aspects of the present invention.
[0040] With this configuration, in a portable electronic equipment,
the vibration motor can be attached into a reduced space as a
silent information means for informing a user of incoming or the
like silently by vibration.
BRIEF DESCRIPTION OF DRAWINGS
[0041] FIG. 1 shows a sectional view of a portable electronic
equipment having a vibration motor holding apparatus according to
an embodiment of the present invention.
[0042] FIGS. 2A, 2B and 2C show configuration views of a motor
shown in FIG. 1.
[0043] FIG. 3 shows a sectional view when the motor shown in FIG.
2A has been mounted on a main-body printed board.
[0044] FIG. 4 shows an exploded perspective view of the main-body
printed board, the motor and a shield case shown in FIG. 3.
[0045] FIG. 5 shows a view showing a state in which the motor has
been mounted on the main-body printed board shown in FIG. 4.
[0046] FIG. 6 shows a sectional view of a main portion of a
background-art cored-type brushless vibration motor.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0047] The present invention will be described in detail with
reference to the accompanying drawings.
[0048] FIG. 1 is a sectional-view of a portable electronic
equipment having a vibration motor holding apparatus according to
an embodiment of the present invention.
[0049] FIGS. 2A to 2C are views each showing a configuration of a
motor shown in FIG. 1.
[0050] FIG. 3 is a sectional view when the motor shown in FIGS. 2A
to 2C is mounted on a main-body printed board.
[0051] FIG. 4 is an exploded perspective view of the main-body
printed board, the motor and a shield case shown in FIG. 3.
[0052] FIG. 5 is a view showing a state in which the motor is
mounted on the main-body printed board shown in FIG. 4.
[0053] In FIG. 1, a transmitting/receiving antenna 3, a receiving
antenna 4, a receiver 5 for outputting voice, a liquid-crystal
display 6 for displaying characters, symbols and so on, a key sheet
7 on which characters/symbols are printed, a transmitter 8, a
main-body printed board 9 and so on are disposed in a case formed
by an upper case 1 and a lower case 2. A battery 10 for supplying
electric power is attached to the outside of the case.
[0054] The upper case 1 has a sound hole 11 for guiding voice
generated from the receiver 5 to the outside of the case, a
plurality of key holes 13, the number of which are as many as those
of protrusions 12 of the key sheet 7 inserted to the key holes 13
correspondingly, an aperture 14 having a size equivalent to that of
the liquid-crystal display 6, and so on. This aperture 14 is closed
by a transparent window 15 such that a user can recognize
characters, symbols and so on displayed on the liquid-crystal
display 6.
[0055] An oscillator for controlling an oscillating frequency by
voltage (thereinafter, referred to as VCO), a plurality of
resistors, capacitors, and so on, are mounted on the back surface
of the main-body printed board 9 so as to form a receiving circuit
portion 16 constituted by a low-noise amplifier, a first mixer and
so on. On the surface side of the main-body printed board 9, a
temperature-compensated quartz oscillator (thereinafter referred to
as TCXO) for stably controlling a frequency, a plurality of
resistors, capacitors and so on are mounted so as to form a radio
circuit portion 17. These receiving circuit portion 16 and radio
circuit portion 17 together with a motor 18 as a vibration motor
and a motor driving circuit (not shown) which are mounted
adjacently thereto are received in and covered with a shield case
19 of resin for preventing invasion of electromagnetic waves from
the outside.
[0056] The shield case 19 is made of resin material such as
acrylonitrile, butadiene, styrene or the like. Non-electrolytic
copper plating is given to the surface of the shield case 19 so
that electromagnetic waves are prevented from passing through the
shield case 19. Non-electrolytic nickel plating is further given to
the surface of the non-electrolytic copper plating so that the
non-electrolytic copper plating is subjected to anti-corrosive
treatment.
[0057] Next, the motor 18 will be described in detail with
reference to FIGS. 2A to 2C. FIG. 2A is a plan view of the motor,
FIG. 2B is a front view, and FIG. 2C is a back view.
[0058] As shown in FIGS. 2A to 2C, the outline of the motor 18 has
a flat shape having a top portion 21, a side portion 22 and a
bottom portion 23. The shape viewed from above is substantially
octagonal. A flat portion 24 which can face a suction chuck of an
automatic sucking machine is formed on the top portion 21.
[0059] In addition, the top portion 21 or the side portion 22 is
provided with a marking 25 for making the attachment direction
distinguishable. The marking 25 is formed by black stamping
(printing) so that the marking 25 has a difference in optical
reflectivity from the surrounding, or the surface of the marking 25
is roughened by laser exposure irradiation so that the surface has
a tone difference from other portions.
[0060] The side portion 22 is surrounded by eight wall surfaces 26
over the whole circumference of the side portion 22. The bottom
portion 23 has eight back-surface terminals 27 so that signal
terminals 28 to 31 and earth terminals 32 to 35 are formed
alternately at substantial centers of respective sides. The rest
portion of the bottom portion 23 is an insulator 36.
[0061] Next, FIG. 3 is a sectional view showing a section taken on
line D-D of FIG. 2A when the motor is mounted on the main-body
printed board.
[0062] In FIG. 3, the motor 18 has a stator 40, a motor printed
board (base) 41, a bearing unit 42, a rotor 43 and a cover 44. The
cover 44 chiefly forms the top portion 21 and the side portion 22,
and the motor printed board 41 forms the bottom portion 23. The
stator 40 is formed by covering the surface of a stator core 45
with insulating film and then winding a coil 46 thereon. A
double-sided through-hole board is used as the motor printed board
41. This motor printed board 41 has a bottom surface, a stator
attachment surface which is a back surface of the bottom surface,
and an outer-circumferential end surface.
[0063] A plurality of surface terminals 47 (four in total) on the
stator attachment opposite sides of the motor printed board 41 are
electrically connected to corresponding back-surface terminals
(only 28 is illustrated in FIG. 3) on the bottom surface side
through through-holes 48.
[0064] In addition, metal surfaces 49 capable of soldering are
formed at eight places of the outer-circumferential end surface so
that the earth terminals 32 to 35 (see FIG. 2C) are electrically
connected to the signal terminals 28 to 31. These metal surfaces 49
are formed at the same time as the through-holes 48. Further, the
bearing unit 42 and the stator 40 are fixed coaxially to the stator
attachment surface of the motor printed board 41. Four terminals of
the coil 46 wound on the stator core 45 are soldered with the
respective surface terminals 47.
[0065] The bearing unit 42 is constituted by a closed-end housing
50, an oilless metal 51, a thrust pad 52, and a shaft 53 inserted
into the thrust pad 52 so that one end of the shaft 53 is fixedly
attached to the center of the rotor 43 by a method of caulking,
pressing-in, welding or the like. The oilless metal 51 is made such
that powder of iron, copper or the like is formed into a porous
body by a powdered metal technique and pores of the porous body are
impregnated with lubricating oil to some extent.
[0066] The rotor 43 has a rotor yoke 55 and an annular magnet 56
fixed to the rotor yoke 55. The above-mentioned shaft 53 is fixedly
attached to the center of the rotor yoke 55. The rotor yoke 55
surrounds the stator 40, and the rotor yoke 55 is supported
rotatably by the bearing unit 42. Further, the rotor 43 has a mass
eccentricity. The mass eccentricity in this case is obtained by
fixedly attaching an arc weight 57 to the outer circumference of
the rotor yoke 55. In order to stabilize the dispersion of the
amount of vibration often generated due to the mass eccentricity, a
control motor is used for stabilizing and controlling the number of
rotations.
[0067] In particular, the control motor is a three-phase brushless
motor for detecting a magnetic position by counter electromotive
force without using any hall device. In the equipment, centrifugal
force F is generated by the rotation of the motor, and this force F
is transmitted to the equipment so that the equipment vibrates. The
centrifugal force F is expressed by the following expression
(1).
F=mr.omega. (1)
[0068] where
[0069] .omega.=2.pi.f;
[0070] m: the weight weighs m,
[0071] r: the barycentric radius
[0072] f: the rotation frequency.
[0073] Therefore, in the case where it is intended to obtain the
same centrifugal force, the barycentric radius r becomes large if
the weight 57 is provided in the outermost circumference of the
rotor 43. Accordingly, the weight 57 can be lightened so that the
weight of the motor 18 can be reduced, As a result, this weight
reduction of the motor 18 can also contribute to weight reduction
in the equipment.
[0074] As has been described above, the cover 44 has an
approximately cup-like shape having the top portion 21 and the side
portion 22. The cover 44 covers the rotor 43, and the forward end
of the side portion 22 abuts on the vicinity of the outer
circumferential edge of the stator attachment surface of the motor
printed board 41. However, part of the forward end does not abut
thereon but forms air holes 58 (also shown in FIG. 2B) connecting
the inside and outside of the cover. In addition, these air holes
58 are connected with the signal terminals 28 to 31 (see FIG. 2C)
so as to have another function as spaces for preventing the signal
terminals 28 to 31 from being short-circuited with the
above-mentioned metal surfaces formed on the outer circumferential
end surface of the motor printed board.
[0075] Further, protrusion portions 59 are formed in the edge
portion of the side portion 22. The protrusion portions 59 (also
shown in FIG. 2B) are soldered and fixed to the metal surfaces 49
connected to the opposite earth terminals of the motor printed
board 41. Here, although the cover 44 is fixed by the
above-mentioned solder, an iron plate is used as the base material
of the cover 44 and subjected to tin plating for anti-corrosive
treatment in order to obtain wettability for solder. Silver, gold,
etc. may be used as alternative plating. Alternatively, nickel
silver (German silver) may be used. In that case, plating is not
required because solder adheres to nickel silver.
[0076] The motor 18 configured thus is mounted as a vibration motor
directly on the main-body printed board 9 of the electronic
equipment.
[0077] Next, the main-body printed board 9 will be described in
detail.
[0078] FIG. 4 is an exploded perspective view of the main-body
printed board, the motor and the shield case.
[0079] In FIG. 4, the main-body printed board 9 has a substantially
rectangular shape. A plurality of notches 61 are formed in the
outer circumference of the main-body printed board 9. Various
electronic parts are mounted on the main-body printed board so as
to form the receiving circuit portion 16 and the radio circuit
portion 17. Further, a plurality of main-body lands 62 opposite to
the back-surface terminals 27 of the motor board 41 are formed near
the receiving circuit portion 16 and the radio circuit portion 17,
and a plurality of line lands (marks for identification) 63
connected to the grounding pattern of the main-body printed board 9
are formed near these main-body lands. These main-body lands 62 and
line lands have another function as identification marks which are
located outside the mounted motor.
[0080] A plurality of hook claws 64 formed in the outer
circumference of the shield case 19 engage with the notches 61
correspondingly, and the shield case 19 is attached to the
main-body board 9 so as to cover the motor 18 as well as the
receiving circuit portion 16 and the radio circuit portion 17. In
this embodiment, a hole 65 is provided in the shield case 19 in
order to avoid interference of the shield case 19 with the flat
portion 24 of the motor 18 in the assembling process. Then, in
order to prevent noise from leaking from this hole 65, the gap
between the top portion 21 and the shield case 19 is set to be not
more than 0.5 mm on the basis of the results of experiments carried
out by the present inventors.
[0081] Next, description will be made about how to mount the motor
18 on the main-body printed board 9.
[0082] FIG. 5 is a plan view showing a state where the motor has
been mounted on the main-body printed board 9.
[0083] In FIG. 5, the line lands 63 are disposed so as to surround
the external form of the mounted motor 18 when the motor 18 is
mounted in a predetermined position on the main-body printed board
9 (FIG. 4) and then the main-body lands 62, the back-surface
terminals 27 (FIG. 2C) of the motor 18 and the metal surfaces 49
(FIG. 3) are connected respectively by solder. That is, when the
motor 18 is mounted on the printed board 9, the motor 18 overlaps
with some of the line lands 63 if the motor 18 is in a state
(mounting displacement) that the motor 18 is somewhat displaced
from the predetermined position or somewhat rotated clockwise or
counterclockwise (mounting displacement). As a result, the
phenomenon can be grasped and recognized visually easily.
[0084] In addition, if the above-mentioned mounting displacement is
produced, some of the main-body lands are hidden by the motor.
Therefore, the phenomenon can be also recognized through the
main-body lands.
[0085] In addition, when this solder passes through a reflow
furnace after being screen-printed on the main-body lands 62, the
main-body lands and the back-surface terminals are soldered and
connected to each other while the main-body lands 62 and the metal
surfaces 49 (FIG. 3), and the main-body lands 62 and the protrusion
portions 59 (FIG. 2B) form fillets 66 (FIG. 3). Without these
fillets 66, for example, it is presumed that falling impact force
generated when the electronic equipment has a fall or the like acts
on the equipment or the motor 18 so as to make the motor 18
separate from the main-body printed board 9. Therefore, the fillets
66 are provided for increasing the separation strength of the motor
18 from the main-body printed board 9 while minimizing the mounting
area of the motor 18. That is, each solder area is equal to the
total amount of areas of the surface terminal 47 and the metal
surface 49 substantially perpendicular to the surface of this
surface terminal 47. Without this metal surface 49, the solder area
would become extremely small, and the area of the surface terminal
would have to be further increased in order to ensure an equivalent
area. Accordingly, the mounting efficiency would be lowered
extremely.
[0086] In addition, in this embodiment, the function of the line
lands 63 as marks for identification is also given to the main-body
lands 62. That is, the main-body lands 62 as well as the line lands
63 are formed to be exposed or bared at positions outside the
outline of the motor so that when there is a mounting displacement
as mentioned above, the line lands 63 or main-body lands 62 can be
hidden by the motor 18.
[0087] Next, description will be made about the assembling and
operation of respective portions with reference to FIGS. 1 to
4.
[0088] First, as shown in FIG. 4, a plurality of hook claws 64 are
hung on the notches 61 of the main-body printed board 9 while one
side (back surface) of the main-body printed board 9 is covered
with the shield case 19. In such a manner, the shield case 19 is
fixedly attached to the main-body printed board 9 (see FIG. 1).
[0089] Next, as shown in FIG. 1, these main-body printed board 9
and shield case 19 together with the receiver 5, the liquid-crystal
display 6 and the key sheet 7 are received in the case constituted
by the upper case 1 and the lower case 2. The transparent window 15
is provided for the aperture 14, and, at last, the battery 10 is
furnished. The equipment is thus completed.
[0090] On the main-body printed board 9, the motor 18 and a motor
driving circuit are mounted together with electronic parts
constituting the receiving circuit 16 and the radio circuit portion
17. The motor 18 is disposed on the main-body printed board 9 by a
mounting machine after solder is screen-printed on the main-body
lands 62 (FIGS. 3 and 4).
[0091] Next, by being passed through a reflow furnace, the solder
is fused and solidified so that the motor 18 and other electronic
parts are electrically connected with the main-body printed board
9. As for the motor 18, the back-surface terminals 27 at the bottom
of the motor is reflow-soldered with the main-body lands 62 of the
main-body printed board 9, from which the electric power is to be
supplied to the coil 46.
[0092] As shown in FIG. 3, the motor driving circuit excites the
stator through the signal terminals 28 to 31 and the surface
terminals 47. As a result, the magnet 56 is driven so that the
rotor 43 is rotated. Since the rotor 43 has a mass eccentricity,
centrifugal force is generated in the equipment together with the
rotation of the rotor 43, and this centrifugal force is transmitted
to the equipment so as to generate vibration of the equipment. For
example, the vibration of the equipment vibrated in a pocket of
clothes of a user is transmitted to the body of the user so that
the user can perceive incoming through the vibration.
[0093] Next, description will be made about consideration which
should be given to the operation of "suction of the automatic
sucking machine".
[0094] The motor 18 in this embodiment is substantially throughout
surrounded by the wall surfaces 26, as shown in FIGS. 2A to 2C. The
flat portion 24 to which a suction chuck can be opposed is provided
substantially at the center of the top portion 21. Specifically,
the flat portion 24 is formed into a circular surface having a
diameter of about 6 mm. Through the flat portion 24, the top
portion can be chucked pneumatically by the air sucking machine.
Therefore, when parts received in a package such as a pallet, a
reel or the like are supplied, the flat portion 24 of the motor 18
received in the package is sucked by the air sucking machine, and
the motor 18 is transferred onto the main-body printed board 9 and
then released from suction. Sucking, transferring and mounting of
the motor 18 is thus accomplished.
[0095] The sucking machine may be a transfer machine provided with
movable chuck claws. In this transfer machine, two opposite sides
of a portion to be sucked are gripped from the outside of the
external form of the portion by a movable chuck after being chucked
pneumatically so that centering is achieved. Preferably, the
opposite sides are formed in parallel and symmetrically with
respect to the center of the portion. In this embodiment, in order
to correspond to an air sucking machine also having movable chuck
claws, the motor cover 44 and the motor printed board 41 are formed
to be substantially octagonal so that centering can be achieved by
chucking the external form of the motor printed board.
[0096] Next, description will be made about measures "during
passage through a reflow furnace" at a high temperature.
[0097] The cover 44 (FIG. 3) can protect the inside of the motor 18
from hot air or infrared rays in a reflow furnace, so that the
motor structure inside the motor 18 can be prevented from being
broken by heating. Flux is mixed into creamy solder to be used in
order to improve wettability of the solder. As this flux is heated,
the flux scatters as a solder ball in which the flux is coupled
with a very small amount of solder. In the case where the scattered
ball adheres to the coil 46 (FIG. 3) or the magnet 56 (FIG. 3),
such a solder ball rubs against the coil 46 or the magnet 56 when
the motor 18 starts its operation. This causes disturbance against
the operation of rotation or occurrence of irregular noise so as to
give a user the impression that the equipment has got out of order.
However, if the cover 44 is provided, it is possible to reduce
courses of invasion of solder balls into the cover 44. Accordingly,
it is possible to avoid unexpected troubles as mentioned above.
[0098] In addition, the forward end of the wall surface 26 (FIG.
2B) of the cover 44 does not abut against the motor printed board
41 (FIG. 3) at portions in the vicinity of the signal terminals 28
to 31 (FIG. 2C). That is, the air holes 58 are provided so that the
inside of the motor 18 communicates with the outside through very
small gaps. Electronic parts constituting the receiving circuit
portion 16 and the radio circuit portion 17 together with the
main-body printed board 9, the motor and so on pass through an
atmosphere at 150.degree. C. to 250.degree. C. for a predetermined
time when they pass through a reflow furnace so as to be mounted on
this main-body printed board 9. At this time, if the inside of the
cover 44 has a closed structure, the internal air expands thermally
so that force to separate the cover from the motor printed board 41
is generated on the inner surface of the cover 44. However, if the
very small air holes 58 which make the outside and inside of the
cover 44 communicate with each other are provided as described
above, it is possible to prevent the internal air from expanding,
so that it is possible to avoid unexpected troubles. In such a
manner, a structure suitable for a reflow mounting system is
realized. Therefore, there is no fear that any harmful influence is
brought by solder balls scattered in a reflow furnace or by passage
of the motor 18 and so on in an atmosphere at a high
temperature.
[0099] Next, description will be made about "inspection after
reflow process".
[0100] At least, if the flat portion 24 or the top portion 21 of
the cover 44 is formed substantially in parallel with the motor
printed board 41, the distance between the upper surface of the
main-body printed board 9 and the flat portion 24 or the top
portion 21 is kept constant after the motor 18 has been mounted
normally. However, when mounting is performed abnormally, for
example, in a condition that dust, dirt or a solder ball is put
between the main-body printed board 9 and the motor printed board
41, the flat portion 24 or the top portion 21 inclines with respect
to the main-body printed board 9. In the mounting process, for
example, the distance between the main-body printed board 9 and the
flat portion 24 is confirmed by an image recognition unit or the
like, so that this inclination is detected. In such a manner, it is
judged whether mounting is performed abnormally or not. However,
unless the distance between the flat portion 24 of the motor 18 and
the motor printed board 41 is formed with precision, there is a
case where mounting is regarded as abnormal though the mounting is
performed normally.
[0101] In this embodiment, the distance between the flat portion 24
and the forward end of the wall surface of the cover 44 which abuts
against the motor printed board 41 is formed with precision by a
mold, and the metal surfaces 49 and the protrusion portions 59 are
connected by solder after the forward end of the wall surface 26
has been brought into abutment against the motor printed board 41.
Therefore, the distance between the main-body printed board 9 and
the flat portion 24 is kept precise after the motor 18 has been
mounted. Accordingly, it is possible to avoid such an
aforementioned fact that mounting is regarded as abnormal though
the mounting is performed normally. Therefore, the height and
inclination of parts which have been mounted can be recognized
accurately, so that it is possible to judge whether the parts are
inclined/floated or not.
[0102] Next, description will be made about "quality".
[0103] The motor for generating vibration shown in this embodiment
is a brushless motor having no brush. Since the motor has the
stator 40 in which the coil 46 is wound on the stator core 45,
however, the inductance is large so that the amount of noise
generated in the motor is larger than that in a coreless-type
motor.
[0104] Even in the case of a so-called brush-type motor having a
brush commutator mechanism, if two brushes abut against one
commutator, a spark is caused by a short-circuit so as to generate
noise.
[0105] Therefore, if an electromagnetic shielding property is given
to the cover 44 in such a manner that the cover 44 is formed of
iron, copper, nickel silver or resin and the surface thereof is
plated, generated noise can be prevented from giving bad influence
to parts close to the motor. Accordingly, it is unnecessary to
electromagnetically shield the motor from other electronic parts by
means of a shield case for preventing electromagnetic waves from
passing, so that it is not necessary to provide ribs or the like
for installing the shield case in a gap between the other
electronic parts and the motor 18. It is therefore possible to save
spaces and clearances for these members and parts to improve the
mounting efficiency. Accordingly, it is possible to save the
space.
[0106] Such an electronic equipment is often used outdoors, and it
may be dropped on the ground when it is taken from a pocket. For
example, when the equipment is dropped on a sandbox in a park or
the like, there is a fear that iron sand or dust contained in sand
makes an invasion into the equipment through a gap of the
equipment.
[0107] Since a brushless outer-rotor motor fulfilled its function
without any cover in itself, it was used without any cover in the
background art. However, when the cover 44 for covering the rotor
43 is provided as in this embodiment, it is possible to prevent
such a fact that iron sand is absorbed by the magnet 56 or dust
invades a gap so as to cause an operation failure. Accordingly, it
is possible to improve the reliability of the motor 18 and the
equipment.
[0108] In addition, the protrusion portion 59 formed at the forward
end of the wall surface 26 is fixed by soldering to the
corresponding metal surface 49 of the motor printed board 41 in
advance. Further, the protrusion portion 59 is connected to the
grounding pattern of the main-body printed board 9, and
electrically connected to the main-body land 62 by solder so that
the cover 44 is grounded. In such a manner, it is designed to solve
such a problem that the cover 44 is electrified so that the
potential thereof changes and a leakage current flows into a land
close to the cover 44 and further transmitted to signal lines or a
VCO on the main-body printed board 9. Accordingly, the accuracy of
frequency modulation is reduced so that stable
transmission/reception is made impossible.
[0109] The marking 25 may be made convex or concave relative to the
environment thereof. The marking 25 may be formed by a mold for
manufacturing a part (a cover in this embodiment) for forming the
top portion 21 or the side portion 22, simultaneously with the
part. This has an advantage that the marking 25 can be used for any
of visual recognition, magnetic reaction, or a height sensor.
Further, a method of using a matter, for example, magnetic ink,
having a difference in magnetic reaction from the environment may
be employed.
[0110] In addition, ferromagnetic material (steel) is suitable for
the material of the cover. The cover can cope with a magnetic chuck
so as to make it possible to use the chuck means substituted for a
pneumatic chuck or a grip chuck. In addition, the ferromagnetic
material is convenient to form a marking using magnetic
reaction.
[0111] The shape of the motor printed board 41 is not always
limited to be substantially octagonal. For example, if it is
substantially quadrilateral, similar operation and effect can be
provided. When the shape of the motor printed board 41 is made
polygonal, that is, when it is made larger than but extremely close
to a circle formed by the outermost shape of the rotating rotor 43,
the area of the motor printed board 41 occupying the main-body
printed board 9 can be reduced, so that the space for mounting can
be saved and the size of the main-body printed board can be
reduced. When the shape of the motor printed board 41 is made
substantially rectangular, it will go well if the back-surface
terminals 27 and the metal surfaces 49 are provided in the outside
of the rotor 43. Then, if the outline of the motor printed board 41
is circular and the marking 25 for indicating the position is
absent, effects similar to those in this embodiment cannot be
obtained. That is, if the marking 25 is not provided and the motor
printed board 41 is circular, in the case where the motor printed
board 41 is mounted so as to rotate in the area surrounded by the
line lands 63 formed in the outside of the motor printed board 41,
the mounting position of the motor printed board 41 cannot be
recognized. In other words, it is necessary to form the motor
printed board 41 into a shape other than a circle, or it is
necessary to provide the marking 25.
[0112] In this embodiment, the mounting position is confirmed by
detecting the position of the marking from above by means of an
image recognition unit, and the presence/absence of the fillets 66
formed in the outside of the outline of the motor and the outline
of the motor printed board 41 is confirmed from above by
irradiation and exposure with laser and by means of the image
recognition unit. In the case where the fillets 66 are present, it
is concluded that the back-surface terminals 27 and the main-body
lands 62 are electrically connected normally.
[0113] In addition, the line lands 63 are provided in the outside
of the outline of the motor printed board 41 so that the line lands
63 can be judged easily even by visually.
[0114] The line lands 63 may have another aspect. Although each of
the line lands 63 is formed into an "L" shape surrounding a ridge
portion formed by two sides of the motor printed board 41 in this
embodiment, it may surround the whole circumference of the motor
printed board 41, or it may be printed or of resist (insulating
film). It will go well if the object of the line lands 63 is
achieved, that is, if the line lands 63 are marks for making it
clear that the position where the motor printed board 41 has been
mounted on the main-body printed board is a predetermined position
after the mounting.
[0115] The reason why the line lands 63 are provided separately
from the main-body lands 62 is as follows. Solder is put on the
surfaces of the main-body lands 62 and the surfaces of the
main-body lands 62 become curved. Accordingly, the main-body lands
62 become impossible to be recognized by the image recognition
unit. Therefore, further lands on which no solder is put (line
lands 63) are provided in this embodiment.
[0116] Incidentally, without providing any line land, the
above-mentioned object can be achieved also by the main-body lands
which are exposed or bared in the outside of the outline of the
motor.
[0117] Although a so-called brushless motor having no brush is used
as the motor 18 in this embodiment, the present invention is not
always limited to this form, but may be realized, for example, with
a brush-type motor having brushes.
[0118] Specifically, such a motor is obtained by improving the form
of a background-art motor such as a flat coreless vibration motor
disclosed in JP-A-6-205565. That is, this flat coreless vibration
motor is constituted by: a rotor having at least three armature
coils disposed in the balance so as not to be overlapped with one
another, and having a plane formed substantially into a fan-shape
as a whole; a shaft disposed at the center of this rotating rotor;
a plate commutator disposed on the rotor so as to be coaxial with
this shaft; a magnet facing the rotor; a brush disposed inside this
magnet and abutting against the plate commutator; and a casing for
storing these parts. First, there are following four problems in
making the motor possible to be subjected to reflow:
[0119] First, the brush and the main-body printed board cannot be
electrically connected by reflow-soldering;
[0120] Secondly, the bottom of the casing is not flat;
[0121] Thirdly, air leakage occurs because of the presence of the
shaft at the center when the motor is sucked, so that the motor
cannot be sucked as one of parts; and
[0122] Fourthly, there is no means for identifying the direction of
the motor after the motor has been mounted on the main-body printed
board.
[0123] In such a flat coreless vibration motor is improved so that
one side (on the bottom side) of the casing to which the magnet is
fixed is configured as a motor printed board, and the magnet is
installed on this motor printed board while the above-mentioned
rotor is provided so as to face this magnet, as in this embodiment,
and further, if a cover for covering the rotating rotor is attached
to the motor printed board as in this embodiment in order to make
it possible that the motor can be sucked by a sucking machine,
there is no fear that the motor printed board rotates when the
motor is sucked. In such a manner, by providing a motor printed
board and a motor cover, such a motor can be reflowed, sucked and
transferred, so that the motor can be improved so as to be
automatically mounted on the main-body printed board.
[0124] As has been described above, according to this embodiment,
the rotating body (rotor) 43 is provided on a base (a motor printed
board) 41 having a shape other than a circle, and the cover 44 for
covering the rotating body is further provided, so that the lower
portion of the cover does not rotate even if the cover is sucked.
Accordingly, there is no change between the states before and after
the suction. When the base is disposed on the main-body printed
board 9 after being transferred, if there are marks outside the
base, it can be easily judged whether the base has been rotated or
displaced.
[0125] In addition, if the position of the marking 25 which can be
confirmed from above is confirmed, it can be easily detected
whether the base is rotated or displaced from its predetermined
position. For example, in the case where the motor printed board 41
is octagonal, if the motor printed board 41 is mounted so as to be
rotated clockwise or counterclockwise by 45.degree. inside the line
lands 63, the marking 25 is rotated by 45.degree. in the same
direction as that of the motor printed board 41 though the motor
printed board 41 is located inside the line lands 63. Therefore,
the mounting can be accurately judged to be abnormal.
[0126] It is not always necessary to provide the marking 25
indicating directivity on the cover. For example, if the motor
printed board 41 has an octagonal shape in which one of the eight
sides differs from the others, or in which a protrusion portion or
a notch is formed in one side, the direction of the motor printed
board 41 can be recognized from above or below by an image
recognition unit. Thus, the marking 25 may be replaced by such a
structure that a portion indicating the directivity is provided on
the outline of the motor printed board 41.
[0127] Although the shield case 19 for covering respective circuits
on the main-body printed board 9 was provided, an electromagnetic
shielding property may be given to the lower case 2, for example,
by providing vapor deposition or plating to the inner surface of
the lower case 2.
[0128] That is, according to the present invention, all the
following steps can be executed without any problem.
[0129] (1) To suck, transfer and mount a vibration motor;
[0130] (2) To pass the vibration motor through a reflow furnace;
and
[0131] (3) To confirm the height and mounting position of the
vibration motor after mounting it.
[0132] Although the present invention has been described about the
process of a vibration motor by way of example, the present
invention may be widely applied to various general forms of motors
other than the vibration motor, automatically wiring process of
other parts, and so on.
[0133] As has been described above, according to the present
invention, in a motor or a vibration motor in which a stator and a
rotor are provided on the surface side of a motor board which is a
base, and either one of the stator and the rotor is made rotatable,
the motor is covered with a cover having a flat portion, and line
lands and main-body lands as marks for identifying the mounting
position are provided outside the outline of the motor board after
terminals formed on the back surface of the motor board are
connected to a main-body printed board by soldering. Accordingly,
there is an effect that the motor or vibration motor becomes easy
to be sucked by an automatic sucking machine in a step, and it can
be easily judged whether the mounting has been performed in an
accurate position, whether the terminals and the main body have
been connected to each other surely, whether the terminals are in
abutment or short-circuit against other parts, and so on.
[0134] In addition, in a vibration motor or a motor in which a
stator and a rotor are provided on the surface side of a motor
board and either one of the stator and the rotor is made rotatable,
and which is covered with an electromagnetically shielding cover, a
shield member is provided to cover parts on a main-body printed
board onto which the vibration motor is mounted, and to store the
vibration motor inside the shield member. Without a special shield
member provided between the vibration motor and the other mounted
parts, a malfunction of any electronic part close to the vibration
motor can be prevented from being caused by noise generated from
the vibration motor. Therefore, there is an effect that a large
mounting area can be ensured on the main-body printed board, the
mounting efficiency is improved, and the size and the weight of the
equipment can be reduced.
[0135] In addition, a flat portion and air holes are formed in the
motor cover, and the cover is configured so that positioning in the
height direction can be performed accurately by making the forward
end of the wall surface of the cover abut against a motor printed
board. Accordingly, there is an effect that suction, transfer and
mounting can be performed accurately in a reflow step. Further, it
is possible to prevent the cover from being removed in the reflow
step, and it is possible to recognize the height of parts with
precision after soldering. Accordingly, the conditions that the
reflow step is carried out are satisfied, so that the work of
manual soldering or the like can be omitted. Therefore, there is an
effect that the equipment can be configured suitably for mass
production.
[0136] In addition, when the motor cover is grounded, the motor
cover can be prevented from electrification. Accordingly, there is
an effect that it is possible to provide an electronic equipment in
which the accuracy of frequency modulation can be kept, and stable
transmission/reception can be attained.
* * * * *