JP2004186382A - Packaging method of electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging method of an electronic component in which any trouble resulting from the mounting height can be eliminated. <P>SOLUTION: In the packaging method of an electronic component where a chucking head 10 having a chucking nozzle 14 picks up a chip P from a component feeding section and mounting it on a board 3, timing of the chip P abutting against the substrate 3 is detected by detecting conduction of a probe 19 provided in the chucking head 10 with an abutting member 18 during a component mounting operation where the chip P held by the chucking nozzle 14 is landed on the substrate 3 by lowering the chucking head. Based on the abutting timing of the component thus detected, unchucking of the chucking nozzle 14 and ascending operation of the chucking head 10 are controlled. A trouble resulting from the mounting height can thereby be eliminated even if the substrate 3 is warped and the height of the upper surface thereof is varied. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic component mounting method for mounting an electronic component on a substrate.
[0002]
[Prior art]
In electronic component mounting, in which electronic components are mounted on a board, a pick-up operation of picking up electronic components stored in a component supply unit by a mounting head and a mounting point on the board by the mounting head moved to a predetermined position on the board. A component mounting operation for landing is performed. In this component mounting operation, it is necessary to lower the suction nozzle holding the electronic component by the elevating means provided on the mounting head, and to stop the electronic component at the height position of the upper surface of the board correctly.
[0003]
Conventionally, the height position of the upper surface of the substrate has been given in advance as mounting height data, and in a mounting operation, a method of controlling the above-described elevating means based on the mounting height data is general. On the other hand, in the case where a substrate of a type for which planar accuracy is not ensured due to undulation or warpage is to be mounted, the warpage of the substrate is measured in advance, and the mounting height data is used as mounting height data during the mounting operation. A method using warpage data is used (for example, see Patent Document 1). As a result, when the substrate surface is in the downward concave state, the electronic component is not yet reached the substrate surface and is released from the suction and holding state. Can be prevented.
[0004]
[Patent Document 1]
JP 2000-26969 A [0005]
[Problems to be solved by the invention]
However, in the above method, since it is necessary to measure the board to be mounted in advance and obtain the warpage data, it is necessary to repeat the measurement operation for each lot when targeting many types of boards, It was not always a practical method. In addition, even when the measurement data is obtained, if there is a mistake in data input or the like, a problem cannot be avoided.
[0006]
Therefore, an object of the present invention is to provide an electronic component mounting method that can eliminate mounting defects caused by mounting height.
[0007]
[Means for Solving the Problems]
2. The electronic component mounting method according to claim 1, wherein the electronic component is picked up from a component supply unit by a mounting head provided with a suction nozzle and mounted on a substrate. In the component mounting operation for landing the electronic component held by the nozzle on the substrate, the contact detection means provided on the mounting head detects the component contact timing at which the electronic component contacts the substrate, and the component contact timing And controlling the vacuum suction means for vacuum suction from the suction nozzle and / or the elevating means for elevating the mounting head.
[0008]
The electronic component mounting method according to claim 2 is the electronic component mounting method according to claim 1, wherein the suction nozzle of the suction nozzle at the component contact timing based on the component contact timing detected by the contact detection unit. The height position is obtained, the obtained height position is compared with a previously stored normal height position range, and the component mounting operation is performed only when the height position is within the normal height position range. Continue to run.
[0009]
According to the present invention, the contact detecting means provided in the mounting head detects the component contact timing at which the electronic component contacts the substrate, and based on the component contact timing, the lifting / lowering means for raising and lowering the mounting head, and By controlling the vacuum suction means for vacuum suction from the suction nozzle, it is possible to secure an appropriate mounting height and reduce mounting defects.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of an electronic component mounting apparatus according to one embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a transfer head of the electronic component mounting apparatus according to one embodiment of the present invention, and FIG. FIG. 4 is a configuration diagram of a suction head provided in a transfer head of the electronic component mounting apparatus according to one embodiment. FIG. 4 is a block diagram illustrating a configuration of a control system of the electronic component mounting apparatus according to one embodiment of the present invention. FIG. 6 is a flowchart of an electronic component mounting operation performed by the electronic component mounting apparatus according to the embodiment of the present invention. FIG. 6 is a process explanatory diagram of the electronic component mounting operation in the electronic component mounting method according to the embodiment of the present invention. FIG. 7 is an explanatory diagram of mounting height determination in the electronic component mounting method according to one embodiment of the present invention.
[0011]
First, the structure of the electronic component mounting apparatus will be described with reference to FIG. In FIG. 1, a transport path 2 is provided in the center of a base 1 in the X direction. The transport path 2 transports the substrate 3 and positions the electronic component at a mounting position. Component supply units 4 are arranged on both sides of the transport path 2, and a large number of tape feeders 5 are arranged in each component supply unit 4. The tape feeder 5 stores the chips (electronic components) held on the tape, and supplies the tape by feeding the tape at a pitch.
[0012]
Y-axis tables 6A and 6B are provided on both ends of the upper surface of the base 1, and two X-axis tables 7A and 7B are provided on the Y-axis tables 6A and 6B. By driving the Y-axis table 6A, the X-axis table 7A moves horizontally in the Y direction, and by driving the Y-axis table 6B, the X-axis table 7B moves horizontally in the Y direction. A transfer head 8 and a camera 9 that moves integrally with the transfer head 8 are mounted on the X-axis tables 7A and 7B, respectively.
[0013]
The transfer head 8 moves horizontally by driving the combination of the Y-axis table 6A, the X-axis table 7A, the Y-axis table 6B, and the X-axis table 7B, and picks up chips from the respective component supply units 4 by suction nozzles. Is mounted on the substrate 3 positioned on the transport path 2. The camera 9 that has moved onto the substrate 3 captures an image of the substrate 3 and recognizes it.
[0014]
A line camera 11 and a nozzle stocker 12 are provided on a path from the component supply unit 4 to the transport path 2. The line camera 11 captures an image of the chip held by each transfer head 8 from below. The nozzle stocker 12 accommodates various suction nozzles corresponding to the chip to be suctioned, and the transfer head 8 accesses the nozzle stocker 12 so that the suction nozzle can be replaced.
[0015]
Next, the transfer head 8 will be described with reference to FIG. As shown in FIG. 2, the transfer head 8 is a multi-type, and has a configuration including a plurality of suction heads 10 as mounting heads, and these suction heads 10 move integrally with the camera 9. Each suction head 10 includes an elevating mechanism 10a provided at an upper end, a shaft mechanism 10b extending downward from the elevating mechanism 10a, and a nozzle holder 10c provided at a lower end of the shaft mechanism 10b. A suction nozzle 14 for sucking and holding a chip is detachably mounted on the nozzle holder 10c, and is replaced according to the type of chip.
[0016]
Each of the suction nozzles 14 can be individually lifted and lowered by a lifting mechanism 10 a serving as a lifting means, and can be rotated around its axis by a common θ-axis motor 13. Each of the elevating mechanisms 10a has a Z-axis motor (not shown), and is mounted on the nozzle holder 10c by receiving a pulse signal from an encoder provided on the Z-axis motor by the height position detector 15. The height position of the lower end of the suction nozzle 14 can be detected.
[0017]
Here, the mounting of the suction nozzle 14 on the suction head 10 and the vacuum suction system will be described with reference to FIG. The nozzle holder 10c provided at the lower end of the shaft mechanism 10b is mounted so as to be allowed to move up and down by a predetermined stroke with respect to the shaft mechanism 10b, and is always mounted by a biasing means built in the shaft mechanism 10b. It is biased downward. A connection hole 10d for external connection is provided on a side surface of the shaft mechanism portion 10b. A vacuum valve 16 is connected to the connection hole 10d. The vacuum valve 16 is further connected to a vacuum pump 17.
[0018]
The suction nozzle 14 has a configuration in which a shaft-shaped main body portion 14a and a disk-shaped flange portion 14c are provided below a tapered fitting engagement portion that fits into a mounting hole of the nozzle holder 10c. The collar portion 14c functions as a reflector that reflects illumination light emitted from an illumination unit attached to the line camera 11.
[0019]
A suction hole 14b is provided vertically through the main body 14a. When the suction nozzle 14 is clamped by the clamp member 10e and mounted on the nozzle holder 10c, the suction hole 14b is connected to the shaft mechanism 10b. It communicates with the vacuum valve 16 through the hole 10d. In this state, the vacuum pump 17 is driven, the vacuum valve 16 is opened, and the vacuum is suctioned from the suction nozzle 14, so that the chip is suction-held in the suction hole 14b. Then, by stopping the vacuum suction by closing the vacuum valve 16, the chip is released from suction and detached from the suction nozzle 14. The vacuum pump 17 and the vacuum valve 16 serve as vacuum suction means for vacuum suction from the suction nozzle 14.
[0020]
Next, a contact detection unit that detects that the chip held by the suction nozzle 14 has contacted the substrate will be described. A disc-shaped contact member 18 is provided on the nozzle holder 10c, and a probe 19 extending downward from the shaft mechanism 10b is opposed to the upper surface of the contact member 18. The contact member 18 and the probe 19 are connected to the conduction detecting unit 20.
[0021]
A buffer spring is mounted on the probe 19, so that even if an upward force is applied to the lower end of the probe 19, the probe 19 is allowed to be displaced upward by an amount corresponding to the bending of the spring, thereby preventing breakage. It has become. When an upward external force acts on the lower end of the suction nozzle 14, the nozzle holder 10 c is displaced upward together with the suction nozzle 14, and the contact member 18 contacts the probe 19.
[0022]
The contact between the probe 19 and the contact member 18 is electrically detected by the conduction detection unit 20, thereby detecting that an upward force acts on the lower end of the suction nozzle 14. By executing the upward force acting on the suction nozzle 14 during the mounting operation of the chip by the suction head 10, it is detected that the chip held by the suction nozzle 14 has contacted the surface of the substrate. You. That is, the contact member 18, the probe 19, and the conduction detecting unit 20 constitute contact detecting means.
[0023]
Next, a configuration of a control system of the electronic component mounting apparatus will be described with reference to FIG. In FIG. 4, a CPU 21 is an operation unit, and performs various processes and operations by executing a program stored in a program storage unit 22 using data stored in a data storage unit 23. The program storage unit 22 stores various programs such as an operation program for an electronic component mounting operation by the transfer head 8 and a substrate transport operation. The data storage unit 23 stores mounting data 23a indicating a mounting position and a chip size of a chip mounted on the substrate 3 and mounting height data 23b indicating a height position of each mounting point of the substrate 3.
[0024]
The conduction detection unit 20 detects that the chip held by the suction nozzle 14 has contacted the substrate by detecting that the probe 19 has conducted to the contact member 18 in the suction head 10. The height position detector 15 detects the height position of the lower end of the suction nozzle 14 based on a pulse signal from the lifting mechanism 10 a of the suction head 10.
[0025]
In the mounting operation in which the suction nozzle 14 holding the chip is lowered with respect to the substrate 3 to land the chip on the substrate 3, a mounting height determination, which will be described later, is performed. That is, the height position of the suction nozzle 14 at the timing when the contact of the chip is detected by the conduction detection unit 20 is detected, and the detected height position is compared with the above-described mounting height data 23b. It is determined whether the mounting operation has been performed normally.
[0026]
The mechanism drive unit 24 drives mechanism units such as the X-axis tables 7A and 7B, the X-axis tables 6A and 6B, and the transfer head 8. The image recognition unit 25 recognizes the position of the substrate 3 by performing a recognition process on image data obtained by imaging with the camera 9, and performs suction processing by recognizing the image data obtained by imaging with the line camera 11. The position of the chip held by the nozzle 14 is recognized. The suction control unit 26 controls opening and closing of the vacuum valve 16 to control suction holding and suction release of the chip by the suction nozzle 14.
[0027]
This electronic component mounting apparatus is configured as described above. Hereinafter, the mounting operation in the electronic component mounting method will be described with reference to FIG. 6 along the mounting operation flow of FIG. First, the transfer head 8 is moved to the component supply unit 4 and the suction head 10 is moved up and down with respect to the tape feeder 5 so that the chip P is sucked by the suction nozzle 14 as shown in FIG. (ST1). Next, the transfer head 8 passes above the line camera 11 and moves above the substrate 3. At this time, the chip P held by the suction nozzle 14 is imaged by the line camera 11, whereby the chip P is recognized (ST2).
[0028]
Thereafter, the transfer head 8 moves to the substrate mounting position (ST3), and positions the suction head 10 with respect to the mounting point. Next, as shown in FIG. 6B, the suction head 10 is lowered (ST4). Thereby, the chip P held by the suction nozzle 14 comes into contact with the upper surface of the substrate 3. By slightly lowering the suction head 10 from this state, as shown in FIG. 6 (c), the probe 19 comes into contact with the contact member 18c and becomes conductive, whereby the contact of the chip P with the substrate 3 is prevented. It is detected (ST5).
[0029]
In response to the detection of the conduction, the suction control unit 26 controls the vacuum valve 16 to stop the vacuum suction from the suction nozzle 14. Thereby, the suction of the chip P is released, and the chip P is mounted on the substrate 3 (ST6). Next, as shown in FIG. 6D, after the chip P is detached from the substrate 3, the suction head 10 moves up (ST7). Thus, the mounting operation of the chip P is completed.
[0030]
In the electronic component mounting method, in the component mounting operation in which the chip P held by the suction nozzle 14 is landed on the substrate 3 by lowering the suction head 10, the chip P is detected by the contact detection means provided on the mounting head 10. The contact timing of the component contacting the substrate 3 is detected, and based on the contact timing of the component, the elevating mechanism 10a for moving the suction head 10 up and down and the vacuum valve 16 of the vacuum suction means for vacuum suction from the suction nozzle 14 are controlled. It has a form.
[0031]
Next, detection of contact of the chip P with the substrate 3 and determination of the mounting height in the mounting operation will be described with reference to FIG. In (ST5) in the flow of FIG. 6, the contact of the chip P held by the suction nozzle 14 is detected, but the contact detection at this time is not necessarily performed when the chip P is in a normal state on the upper surface of the substrate 3. It does not guarantee that the contact has occurred. For example, when foreign matter such as a dropped component exists at a mounting point on the substrate 3, when the suction nozzle 14 is lowered, the chip P comes into contact with the foreign matter.
[0032]
Continuing the mounting operation in such an abnormal state not only causes mounting errors but also causes machine troubles such as nozzle breakage. Therefore, in the electronic component mounting method described in this embodiment, the chip P At the contact detection timing, a mounting height determination described below is performed to determine whether a normal mounting operation is performed.
[0033]
FIG. 7 shows the normal height position range of the mounting height in the component mounting operation. The substrate to be mounted does not always have good planar accuracy, and the surface height may vary due to undulation or warpage. Even when such a substrate is targeted, in the mounting operation by the electronic component mounting apparatus described in the present embodiment, the contact of the chip P with the substrate 3 is detected by the contact detection means. Irrespective of the presence or absence of variations in the height of the substrate surface, the suction of the suction nozzle 14 can be released at the correct timing.
[0034]
However, when the degree of height variation is locally significant or when foreign matter is present at the mounting point, the mounting operation cannot be continued as it is, and some countermeasure is required. For this reason, in the electronic component mounting method of the present embodiment, as shown in FIG. 7, the upper allowable height HU and the lower allowable height are respectively shifted upward and downward from the height position of the surface 3a of the substrate 3 in the normal state. A range between the upper limit U and the lower limit L separated by HL is set as a normal height position range in which the mounting operation can be performed normally, and is stored in the data storage unit 23 as mounting height data 23b. The upper allowable height HU and the lower allowable height HL are allowable heights at which the chip P can be normally mounted on the upper convex substrate 3 and the lower concave substrate 3, respectively.
[0035]
Then, based on the component contact timing detected by the above-described contact detection means, the height position of the lower end of the suction nozzle 14 at the component contact timing is determined by the height detection unit 15, and the determined height position is determined. Is compared with the normal height position range included in the mounting height data 23b stored in advance, and the component mounting operation is continuously performed only when the detected height position is within the normal height position range. I am trying to do it. In the mounting height data 23b, a height position in consideration of the thickness t of the chip P is stored for each mounting point, and even when different components having different thickness dimensions are erroneously mounted, the height position is not changed from the normal height position range. Erroneous mounting can be detected as a deviation from.
[0036]
That is, when the detected height position is out of the above-described normal height position range, it is determined that the mounting operation is not normally performed, the mounting operation is stopped, and the notification unit notifies the user of the fact. Notify. Examples of improper mounting operations include the case where the board is excessively warped and deformed, the presence of foreign matter at the mounting point on the board, and the erroneous mounting of the different parts described above.
[0037]
As described above, in the electronic component mounting method according to the present embodiment, the component contact timing at which the chip contacts the substrate is detected, and based on the component contact timing, the suction release of the suction nozzle and the suction head are performed. To make the rise. As a result, even if the board to be mounted is warped, it is possible to secure an appropriate mounting height without performing complicated work such as pre-measurement of the board and inputting measurement data required by the conventional method. Mounting defects such as chip displacement can be reduced.
[0038]
【The invention's effect】
According to the present invention, the contact detecting means provided on the mounting head detects the component contact timing at which the electronic component contacts the substrate, and the lifting / lowering means for raising and lowering the mounting head based on the component contact timing. Further, by controlling the vacuum suction means for vacuum suction from the suction nozzle, it is possible to secure an appropriate mounting height and reduce mounting defects.
[Brief description of the drawings]
FIG. 1 is a plan view of an electronic component mounting apparatus according to one embodiment of the present invention; FIG. 2 is a diagram illustrating a configuration of a transfer head of the electronic component mounting apparatus according to one embodiment of the present invention; FIG. 4 is a configuration diagram of a suction head provided in a transfer head of the electronic component mounting apparatus according to one embodiment. FIG. 4 is a block diagram illustrating a configuration of a control system of the electronic component mounting apparatus according to one embodiment of the present invention. 5 is a flowchart of an electronic component mounting operation by the electronic component mounting apparatus according to one embodiment of the present invention. [FIG. 6] A process explanatory diagram of an electronic component mounting operation in an electronic component mounting method according to one embodiment of the present invention. FIG. 7 is an explanatory diagram of mounting height determination in the electronic component mounting method according to one embodiment of the present invention.
3 Substrate 8 Transfer head 10 Suction head 14 Suction nozzle 15 Height position detector 16 Vacuum valve 17 Vacuum pump 18 Contact member 19 Probe 20 Conduction detector

Claims (2)

An electronic component mounting method in which an electronic component is picked up from a component supply unit by a mounting head having a suction nozzle and mounted on a substrate, and the electronic component held by the suction nozzle is landed on the substrate by lowering the mounting head. In the component mounting operation to be performed, the contact detection means provided in the mounting head detects the component contact timing at which the electronic component contacts the substrate, and based on the component contact timing, vacuum suction is performed from the suction nozzle. An electronic component mounting method, comprising: controlling a vacuum suction means and / or a lifting means for lifting and lowering the mounting head. The height position of the suction nozzle at the component contact timing is determined based on the component contact timing detected by the contact detection unit, and the determined height position is stored in a normal height position range. 2. The electronic component mounting method according to claim 1, wherein the component mounting operation is continuously performed only when the height position is within the normal height position range, as compared with the height of the electronic component. 3.

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