U.S. patent application number 09/793228 was filed with the patent office on 2001-10-18 for apparatus and method for mounting electronic component.
Invention is credited to Sakaguchi, Hiroyuki.
Application Number | 20010030298 09/793228 |
Document ID | / |
Family ID | 18569251 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010030298 |
Kind Code |
A1 |
Sakaguchi, Hiroyuki |
October 18, 2001 |
Apparatus and method for mounting electronic component
Abstract
Apparatus and method for mounting electronic components enhanced
in mounting efficiency by eliminating loss time are disclosed. In
the apparatus and method, electronic components are picked up from
a supplying unit of the electronic components by a transfer head,
and are mounted on a board. The height of components already
mounted on the board being conveyed is measured by a height
measuring unit comprising a CCD light sensor including a light
emitting unit and a light receiving unit. In mounting operation,
the transfer height of the transfer head when moving on the board
is set to a height enough to keep an allowance to the already
mounted components on the basis of the height measurement of
components. As a result, without useless elevating motions of the
transfer head, the loss time is eliminated and the mounting
efficiency is enhanced.
Inventors: |
Sakaguchi, Hiroyuki;
(Fukuoka, JP) |
Correspondence
Address: |
Lawrence E. Ashery
Ratner & Prestia, Suite 301
One Westlakes, Berwyn
P.O. Box 980
Valley Forge
PA
19482-0980
US
|
Family ID: |
18569251 |
Appl. No.: |
09/793228 |
Filed: |
February 26, 2001 |
Current U.S.
Class: |
250/559.29 ;
250/200 |
Current CPC
Class: |
H05K 13/0413 20130101;
H05K 13/0812 20180801; H05K 13/0853 20180801 |
Class at
Publication: |
250/559.29 ;
250/200 |
International
Class: |
G01J 001/00; H01J
040/00; G01V 008/00; G01N 021/86 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 24, 2000 |
JP |
2000-046917 |
Claims
What is claimed is:
1. An apparatus for mounting electronic component for picking up an
electronic component from a supplying unit of an electronic
component and mounting the electronic component on a board, by a
transfer head, comprising: component height measuring means for
measuring a height of a component already mounted on said board,
and transfer height control means for controlling a transfer height
when said transfer head moves on the board on the basis of a result
of measurement by said component height measuring means.
2. The apparatus for mounting electronic component of claim 1,
wherein said component height measuring means comprises a light
sensor including a light emitting unit and a light receiving unit,
and the light sensor measures a height of a component to be
measured depending on light emitted from the light emitting unit
and received in the light receiving unit.
3. The apparatus for mounting electronic component of claim 1,
wherein said component height measuring means includes distance
measuring means for measuring a height at each point on said board
as an optical distance.
4. The apparatus for mounting electronic component of claim 1 or 3,
wherein said component height measuring means measures the height
of the electronic component already mounted on said board in
relation to a position on said board.
5. A method for mounting electronic component for picking up an
electronic component from a supplying unit of the electronic
component and mounting the electronic component on a board, by a
transfer head, comprising the steps of: (a) measuring a height of a
component already mounted on said board, and (b) controlling a
transfer height when said transfer head moves on said board on the
basis of result of measurement of the height at said step (a).
6. The method for mounting electronic component of claim 5, wherein
at said step (a), when said board having the component already
mounted moves on a transfer route, a light sensor including a light
emitting unit and a light receiving unit emits light from the light
emitting unit, and the light sensor detects a light shielding range
by the component already mounted, and measures a height of the
component already mounted.
7. The method for mounting electronic component of claim 5, wherein
at said step (a), the height of each of the component already
mounted on said board is measured as an optical distance, and the
height of the component already mounted is determined.
8. The method for mounting electronic component of claim 5 or 7,
wherein at said step (a), the height of the component already
mounted on said board is measured in relation to a position on the
board.
9. A method for mounting electronic component employing a plurality
of apparatuses for mounting electronic component, each one of said
plurality of apparatuses for mounting electronic component picking
up an electronic component from a supplying unit of the electronic
component and mounting the electronic component on a board by a
transfer head, wherein a transfer height when said transfer head
moves on said board is controlled on the basis of: height data of
i) a component to be mounted in said each apparatus, and ii) a
component already mounted before mounting operation in said each
apparatus.
10. The apparatus for mounting electronic component of claim 1,
wherein said transfer height control means i) determines a height
corresponding to a height of a component to be mounted as a first
transfer height, and ii) if the component already mounted is
present in a moving path of said transfer head, determines a second
transfer height so that said transfer head may move above the
component already mounted, while keeping a predetermined clearance
between the component already mounted and the component to be
mounted, on the basis of the height of the component already
mounted and the height of the component to be mounted, and said
transfer head mounts the component to be mounted on a specified
point on said board after keeping at least one of the first and
second transfer heights.
11. The method for mounting electronic component of claim 5,
wherein said step (b) i) determining a height corresponding to a
height of a component to be mounted as a first transfer height, and
ii) if the component already mounted is present in a moving path of
said transfer head, including a step of determining a second
transfer height so that said transfer head may move above the
component already mounted, while keeping a predetermined clearance
between the component already mounted and the component to be
mounted, on the basis of the height of the component already
mounted and the height of the component to be mounted, and the
component to be mounted is mounted on a specified point on said
board after keeping at least one of the first and second transfer
heights.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus for mounting
electronic components on a board, and a method for mounting
electronic components.
BACKGROUND OF THE INVENTION
[0002] In an apparatus for mounting electronic components on a
board, electronic components stored in a supplying unit are picked
up by a transfer head having nozzles for holding components by
vacuum suction, and transferred onto the board, and mounted on
specified mounting positions.
[0003] In this mounting operation, the transfer head moves on the
board until reaching the specified mounting positions. On this
moving path, electronic components may have been already mounted in
a preceding process.
[0004] In such a case, the height of the transfer head must be set
at the time of transfer so that electronic components held in the
transfer head may not interfere with the existing electronic
components.
[0005] In this case, regardless of the type of the board to mount
on, generally, interference is prevented in mounting operation by
elevating the transfer head to the highest transfer height of the
mounting apparatus, so as not to cause an interference with the
highest electronic components.
[0006] The height differs with the type of electronic components.
When the board differs, the height of electronic components to be
mounted is also different. If the transfer height of the transfer
head in mounting operation is kept constant regardless of the type
of the board, the transfer head is raised to an unnecessary height
depending on the type of the electronic component to be mounted on
the board. That is, the transfer head ascends and descends
wastefully. Such unnecessary elevating motions are repeated in
every mounting operation, and there is a loss time in the cycle
time.
SUMMARY OF THE INVENTION
[0007] It is hence an object of the invention to present an
apparatus and method for mounting electronic component capable of
eliminating loss time and enhancing the mounting efficiency.
[0008] The apparatus for mounting electronic component of the
invention, in order to pick up electronic components from a
supplying unit of electronic components and mount them on a board,
by a transfer head, comprises:
[0009] a) component height measuring means for measuring the height
of components already mounted on the board before mounting
operation by this apparatus for mounting electronic component,
and
[0010] b) transfer height control means for controlling the
transfer height, when the transfer head moves on the board in
mounting operation, on the basis of result of measurement by this
component height measuring means.
[0011] The method for mounting electronic component of the
invention, in order to pick up electronic components from a
supplying unit, and mount them on a board, by a transfer head,
comprises the steps of:
[0012] a) measuring the height of components already mounted on the
board before mounting operation of electronic component, and
[0013] b) controlling the transfer height, when the transfer head
moves on the board in mounting operation, on the basis of result of
measurement of component height.
[0014] According to the invention, the transfer height of the
transfer head that picks up electronic components from a supplying
unit and transfers them onto the board is determined on the basis
of the height of components already mounted on the same board.
Therefore, useless elevating motions of the transfer head are
eliminated, the loss time is killed, and the mounting efficiency is
enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of an apparatus for mounting
electronic component in an embodiment of the invention.
[0016] FIG. 2 shows a part of the apparatus for mounting electronic
component in the embodiment of the invention.
[0017] FIG. 3 is a block diagram showing a configuration of control
system of the apparatus for mounting electronic component in the
embodiment of the invention.
[0018] FIG. 4 shows a moving operation pattern of transfer head in
electronic component mounting operation in an embodiment of the
invention.
DESCRIPTION OF TIE PREFERRED EMBODIMENTS
[0019] A preferred embodiment of the invention is described while
referring to the accompanying drawings.
[0020] Referring first to FIG. 1, a mounting apparatus of
electronic components is explained. In FIG. 1, in the middle of a
platform 1, a transfer route 2 is disposed in the X-direction. The
transfer route 2 is a positioning unit for transferring and
positioning a board 3. At both sides of the transfer route 2,
supplying units 4 of electronic components are disposed. The
supplying unit 4 includes a tape feeder 5 for feeding taped
electronic components, and a tray feeder 6 for feeding electronic
components contained in a tray 7.
[0021] A transfer head 9 of electronic components 110 is mounted on
an X-axis table 8. The transfer head 9 is a multi-head type, and
comprises plural nozzles 11. The X-axis table 8 is supported by a
pair of parallel Y-axis tables 10. By driving the X-axis table 8
and Y-axis tables 10, the transfer head 9 moves horizontally. The
nozzle 11 disposed at the lower end of the transfer head 9 picks up
the electronic component 110 from the pickup position 5a of the
tape feeder 5 and specified tray 7 of the tray feeder, and
transfers the electronic component 110 onto the board 3 on the
transfer route 2.
[0022] On the moving path of the transfer head 9 between the
transfer route 2 and the supplying unit 4, a line camera 15 is
disposed. The transfer head holding the electronic component moves
horizontally above the line camera 15. At this time, the line
camera 15 receives the light entering through the optical system by
a one-dimensional line sensor, and recognizes the electronic
component held on the transfer head.
[0023] At the upstream side (left side in FIG. 1) of the transfer
route 2, there is a board receiving unit 16 for receiving the board
3 on which electronic components are already mounted partly from a
previous process.
[0024] As shown in FIG. 2, in the board receiving unit 16, there is
a one-dimensional CCD light sensor 17 including a light emitting
unit 17a and a light receiving unit 17b facing each other at both
sides of the transfer route 2. When the partly packed board 3 is
transferred on the transfer route 2, as shown in FIG. 2, in a state
of the light being emitted from the light emitting unit 17a, the
already mounted components on the board 3 cross the emitted light.
Therefore, the range shielded by the already mounted component 120
and the range of the emitted light directly received in the light
receiving unit 17b are distinguished and detected. Thus, by the
shielded state of the light emitted from the light emitting unit
17a and received in the light receiving unit 17b, the data of
height "H" of the already mounted component 110 to be measured is
obtained. The data is sent to a height measuring unit (described
below).
[0025] Referring now to FIG. 3, the configuration of the control
system is explained. In FIG. 3, a controller 20 includes a CPU, and
controls the operation of the entire apparatus for mounting
electronic component. A program storage unit 21 stores necessary
programs for various operations such as sequence program of
mounting operation. The program includes an elevation height
control program in the operation pattern when moving the transfer
head. A data storage unit 22 stores various data such as mounting
coordinates data and component data.
[0026] A mechanics controller 24 controls driving of motors for
driving the XY table mechanism or transfer head 9. A
recognizing/processing unit 25 processes image data of the
electronic component 110 taken by the line camera 15, and
identifies the component 110 and recognizes the position of the
component 110. Then, the electronic component 110 is in a state
held on the transfer head 9. An operating/inputting unit 26
includes operation buttons and keyboard provided in an operation
panel, and enters component data such as tray height data, and
operation commands.
[0027] A height measuring unit 27 measures the height of the
already mounted component on the board 3 on the basis of the signal
from the CCD light sensor 17. The CCD light sensor 17 and height
measuring unit 27 are means for measuring the height of the
existing components. The result of height measurement is sent to
the controller 20, and the controller 20 controls the drive
mechanism of the transfer head 9 on the basis of the sequence
program and the height measurement result. Accordingly, in mounting
operation, when the transfer head 9 moves on the packed board, the
transfer head 9 moves at a transfer height corresponding to the
height of the already mounted component on the packed board 3.
Therefore, the controller 20 functions as transfer height control
means for controlling the transfer height of the transfer head 9 on
the basis of the height measurement result.
[0028] Referring now to FIG. 4, the operation pattern of the pickup
operation by the transfer head 9 is explained.
[0029] This operation pattern is executed on the basis of i)
operation program stored in the program storage unit 21, and ii)
component data stored in the data storage unit 22.
[0030] FIG. 4 shows height changes during horizontal move of the
transfer head 9, that is, changes of the height "h" at the lower
end of the nozzle 11 mounted on the transfer head 9 in three
actions of i) pickup of component from the tape feeder 5 or tray 7
of supplying unit 4, ii) recognition of component by line camera
15, iii) mounting components on board 3.
[0031] In FIG. 4, after picking up the electronic component 110
from the tape feeder 5 or tray 7, the transfer head 9 elevates to
height "h1". This height "h1" is set at a height proper for the
transfer head 9 to transfer the electronic component 110 stably, on
the basis of the data including the height of the tray 7 in which
the electronic component 110 has been stored and the height of the
component. The height data are preliminarily stored in the data
storage unit 22 as component data.
[0032] After elevating up to the transfer height "h1", the transfer
head 9 moves to the line camera 15, and the height is changed
herein to the specified recognition height "h2". This recognition
height "h2" is the height determined by the imaging characteristic
of the line camera 15.
[0033] After recognizing this height, the transfer head 9 changes
its height to a different height "h3" until reaching the mounting
point on the board 3. This height "h3" is determined by the height
of the component 120 already mounted on the board 3 which has been
determined by the height measuring unit 27. That is, the height is
set so that a specified allowance "C" may be held between the lower
surface of the electronic component P110 held on the transfer head
9 and the upper surface of the already mounted component 120.
[0034] The apparatus for mounting electronic component is thus
composed. The method for mounting the electronic component 110 is
explained below.
[0035] First, in the board receiving unit 16 of the transfer route
2, the board 3 for mounting on is supplied from the preceding
process. When the board 3 moves on the transfer route 2, the height
of the already mounted component 120 is measured by the CCD light
sensor 17 and height measuring unit 27. On the basis of the result
of measurement, the maximum height of the component 120 on the
board 3 is determined. This maximum height data is transmitted to
the controller 20.
[0036] Thus, the CCD light sensor 17 and height measuring unit 27
determine the height of components already mounted on the board
3.
[0037] Next, the transfer head 9 picks up the electronic component
110 from the tray 7 of the supplying unit 4. At this time, after
sucking up the electronic component 110, the transfer head 9
elevates to transfer height "h1", that is, to a safe height not
causing interference between the bottom of the electronic component
110 held on the nozzle and the upper edge of the tray. While
keeping this transfer height, it moves onto the line camera 15, and
descends to recognition height "h2". Keeping this recognition
height "h2" during image taking, it moves onto the board 3, and
mounts the held electronic component 110 on the mounting
position.
[0038] At this time, the controller 20 controls the mechanics
controller 24 on the basis of the maximum height data of the
already mounted components 120. As a result, when the electronic
component 110 held on the transfer head 9 moves above the already
mounted component 120, a specified allowance "C" is always kept, so
that the transfer head 9 moves at a proper height without ascending
or descending wastefully. Therefore, useless elevating motions in
the mounting operation is eliminated, the loss time is killed, and
the mounting cycle time is shortened.
[0039] Such operation is executed every time the component held on
the transfer head 9 moves above the already mounted components.
[0040] Alternatively, by storing the height and width of already
mounted components in the data storage unit 22 as component data,
the allowance "C" may be held on the basis of the height of each
already mounted component.
[0041] Yet alternatively, the transfer head 9 may be moved by
keeping the specified allowance "C" on the basis of the highest
component of the already mounted components.
[0042] In this embodiment, the height measuring means is realized
by a transmission type CCD light sensor 17 composed of light
emitting unit 17a and light receiving unit 17b, but in other
method, for example, a laser displacement meter may be used as
distance measuring means for measuring the height at each point on
the plane of the board as an optical distance from the laser
displacement meter.
[0043] By using such height measuring means, the height of the
electronic components mounted on the board may be measured in
relation to the position on the plane of the board.
[0044] That is, the CCD light sensor can measure the height in
relation to the position in the X-axis direction. Further, the
distance measuring instrument for measuring the height at each
point on the plane of the board as an optical distance from itself,
such as the laser displacement meter, can measure the height at the
position on the X-axis and Y-axis.
[0045] Therefore, the instrument such as the laser displacement
meter is capable of measuring more finely as compared with the
component height measurement by using transmission type light
sensor which is capable of measuring the height only in a linearly
scanning mode.
[0046] For example, in height measurement in linearly scanning
mode, the height of a component existing only in part is detected
as the height representing the scanning width to which the
component belongs. Therefore, when the moving path of the transfer
head 9 crosses the scanning width, transfer height "h3" is set on
the basis of the representative height. Accordingly, a component
presenting the representative height may not be always present in
the actual moving path. It may hence cause useless elevating
motions of the transfer head 9.
[0047] By contrast, in the case of the height measurement in
relation to the position on the plane of the board, the height of
components positioned in the moving path is individually
determined. Therefore, when setting the transfer height of the
transfer head when moving on the board, the height is set on the
basis of the height of the components actually existing in the
moving path. Therefore, useless actions are eliminated more
thoroughly.
[0048] Suppose a plurality of apparatuses for mounting electronic
components are coupled in series to compose one electronic
component mounting line.
[0049] In this case, data of each mounting stage, that is, various
data including height of electronic components to be mounted in the
mounting operation in each apparatus for mounting electronic
components and components mounted already in the mounting stage,
are already known by mounting data.
[0050] Therefore, in mounting operation at each apparatus for
mounting electronic components, the transfer height of the transfer
head when moving on the board is set on the basis of the data of
height of components already mounted in the previous stage. Thus,
height measurement of components on the board in the embodiment is
not required on every occasion in each mounting stage, so that the
cycle time can be also shortened.
[0051] According to the invention, the transfer height of the
transfer head when picking up the electronic component from the
supplying unit and transferring onto the board is determined on the
basis of the height of the components already mounted on the board.
Therefore, eliminating unnecessary elevating motions of the
transfer head, loss time is killed, and the mounting efficiency is
enhanced.
* * * * *