JP2625948B2 - Electronic component mounting apparatus and electronic component mounting method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an electronic component mounting apparatus and an electronic component mounting method, and relates to a vertical stroke of a nozzle for sucking an electronic component in response to a change in the thickness of the electronic component. Can be adjusted.

(Prior art) Electronic component mounting equipment that mounts electronic components such as ICs and LSIs on a board takes up electronic components placed on wafers and trays by adsorbing electronic components to the lower end of a nozzle. , And are transferred to and mounted on a substrate.

FIG. 7 shows a conventional nozzle elevating means, in which 101 is a nozzle, 102 is an elevating shaft, and 103 is a shaft 102.
Is a driving member for pressing the shaft 102 downward, and 105 is a rotating shaft driven by a motor (not shown). This is a rotating shaft 105
Is rotated, the elevating shaft 102 is driven by the driving member 104.
, And descends against the spring force of the spring material 103 to attract and take up the electronic components P mounted on the wafers and trays. Also, when the sucked electronic component P is mounted on the substrate, the nozzle 101 moves up and down in the same manner.

(Problems to be Solved by the Invention) By the way, although the thickness of the electronic component P is various, conventionally,
Since the stroke S of the nozzle 101 was constant, there were the following problems. That is, when the electronic component P is taken up, or when the electronic component P is thick, FIG.
As shown in (1), the lower end of the nozzle 101 strongly hits the upper surface of the electronic component P, and the electronic component P is broken. In addition, FIG.
When the electronic component P is thin as shown in FIG.
Cannot land on the upper surface of the electronic component P and the interval t occurs, so that the electronic component P cannot be taken up reliably. Such inconvenience also occurs when the electronic component lands on the substrate.

As means for solving such a problem, it is conceivable to control the amount of rotation of the shaft 105 by a computer so that the stroke of the elevating shaft 102 is adjusted according to the change in the thickness of the electronic component. However, this causes a new problem as described below.
That is, FIG. 9 shows a curve of the descending speed V and the stroke S of the nozzle 101. The descending start time is the maximum descending speed Vmax, and the descending end is the minimum speed Vmin. Therefore, when the thickness of the electronic component is small, the elevating time t1 is increased so that the long stroke S1 is obtained, and when the thickness of the electronic component is large, the short stroke S2 is obtained. The lifting time t2 must be shortened. In this case, as is clear from the figure, the final descending speed V2 when thick is higher than the final descending speed V1 when thin. This means that the thicker the electronic components, the more
The lower end of the nozzle 101 strongly hits the upper surface of the electronic component at a high speed, which means that the electronic component is easily broken.
Further, when the thickness of the electronic component is thin, the time required to obtain a necessary stroke becomes long, which means that the mounting speed is reduced. As described above, it is difficult for the conventional means shown in FIG. 7 to properly cope with a change in the thickness of the electronic component.

Therefore, the present invention responds to changes in the thickness of electronic components,
A first object is to provide means for easily adjusting the up / down stroke of the nozzle. In addition, in order to be able to perform mounting work at a high speed, raise and lower the nozzle as fast as possible, and at the same time make the nozzle as low as possible when landing on the upper surface of the electronic component or when landing the electronic component on the board. It is a second object of the present invention to provide means for minimizing the impact on electronic components.

(Means for Solving the Problems) An electronic component mounting apparatus of the present invention is driven by a lifting shaft that drives a nozzle that sucks an electronic component up and down, a driving member that drives this lifting shaft up and down, and a first motor. A first cam, a second cam driven by a second motor, a first transmission member for changing the position of the second cam in conjunction with the movement of the first cam, and a second cam A second transmission member for driving the driving member so as to move the elevating shaft up and down in conjunction with the movement of the electronic component, and data of the thickness of the electronic component mounted on the substrate are stored. Second
And a control device for controlling the motor.

Further, the present invention is an electronic component mounting method in which a first cam driven by a first motor and a second cam driven by a second motor move up and down a nozzle for vacuum suction of an electronic component. By driving the first cam and the second cam at the same time, the nozzle is lowered at a high speed. When the nozzle approaches the target height, the driving of the second cam is stopped and the second cam is stopped. Driving the first cam to lower the nozzle at a low speed to a target height;
The driving amount of the cam and / or the second cam is controlled by the control device according to the thickness of the electronic component.

(Operation) In the above configuration, the up / down driving of the nozzle for take-up of the electronic component and landing on the substrate is performed by driving the first cam and the second cam. In this case, the nozzle
When the first cam and the second cam are driven together, they descend at a high speed, and when the nozzle approaches the target height, it descends at a low speed by one of the cams. In addition, by controlling the driving amount of the first cam and / or the second cam by the control device according to the thickness of the electronic component, the up / down stroke of the nozzle can be adjusted according to the thickness of the electronic component.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an electronic component mounting apparatus, which has three heads: a sub-transfer head A, a mount head B, and a transfer head C. Although these three heads A, B, and C have basically the same structure, the sub-transfer head A and the mount head B are equipped with a nozzle 1 for sucking electronic components, whereas the transfer head C is There is a structural difference in that a transfer pin 2 for attaching a bond is provided. The nozzle may be a die collet type nozzle having a box-shaped suction unit. As will be described later in detail, these three heads A, B, and C perform a series of operations such as correction of misalignment of electronic components, mounting of electronic components on a substrate, and application of a bond to a substrate in a lateral direction. Perform simultaneously while reciprocating and sliding together.

Reference numeral 3 denotes a support portion, and 4 denotes a guide portion provided on the support portion 3, and a fitting portion 22 provided on the back surface of the heads A to C is slidably fitted on the guide portion 4. 40 is the support 3
, A lateral drive device provided on the side of, 41 is a drive box, 42 is a drive motor, 43 is a lifting shaft, 44, 4
Reference numeral 5 denotes a link, and reference numeral 46 denotes a rod connected to the head C. When the motor 42 is driven, the three heads A, B, and C reciprocally slide along the guide portion 4 in the horizontal direction.

Below the heads A, B, and C, an electronic component supply unit 10, a substage 11, a positioning unit 12 for a substrate 14, and a bond supply unit 13 on which a bond plate 9 is placed are arranged. As a substrate,
In addition to a normal substrate, a lead frame may be used. In the electronic component supply unit 10, a wafer 15 equipped with electronic components P is placed. Reference numeral 16 denotes a mounting table for the wafer 15, and 17 denotes a die ejector. When the table 16 rotates, a desired wafer 15 moves above the die ejector 17. 46
Is a drive shaft extending from the drive box 40, which pushes up and down the pins 17a of the die ejector 17 to push up the electronic components P on the wafer 15. Note that the supply unit 10 may be equipped with a tray or the like instead of a wafer.

The substage 11 is a stage for correcting a displacement of the electronic component P in the xyθ direction, performing observation with a camera, and the like. The positioning unit 12 is composed of XY direction moving devices 18 and 19, and moves the substrate 14 positioned above it in the XY direction to lower the nozzle 1 to a predetermined position on the substrate 14. Next, the detailed structure of the mount head B will be described with reference to FIGS. 2 and 3. As described above, the other heads A and C have the same structure as the mount head B.

Reference numeral 21 denotes a frame serving as a main body of the mount head B. As described above, a fitting body 22 slidably fitted to the guide portion 4 is mounted on the back surface thereof. 25 is a slider, 26 is a first cam driven by a first motor M1, 27 is a cam follower, 28 and 29 are first transmission members formed of links, and when the cam 26 rotates, the slider 25 moves in the front-rear direction. Reciprocating sliding to N. 31 and 32 are guide members of the slider 25. M2 is a second motor provided on the slider 25; 33 is a second cam driven by the motor M2; 34 is a cam follower; 35 is a second transmission member that supports the cam follower 34; Material. Note that the motor M2 is a pulse motor and is controlled by the control device 50 including a computer. 2 and 3, when the first motor M1 is driven and the slider 25 advances and retreats in the direction of arrow N, the second cam 33 on the slider 25 advances and retreats in the same direction and moves to the position. change. 36 is the above frame 21
A roller 38 pivotally mounted on a lower end of the transmission member 35 is in contact with a driving member which is rotatably supported by a pin 37. Reference numeral 39 denotes a roller pivotally mounted on the distal end of the driving member 36, 51 denotes a plate on which the roller 39 is grounded, 52 denotes an elevating shaft of the nozzle 1 suspended from the plate 51, and 53 denotes a biasing spring material. , 54 are guide shafts.

FIG. 4 schematically shows the lifting / lowering means of FIG. 3 for easy understanding.
Will be described. When the first cam 26 rotates, the first transmission member 29 and the slider 25 slide back and forth in the front-rear direction N. L1 is the sliding stroke. Also, the second cam 33
When rotates, the second transmission member 35 also moves in the front-back direction. L2 is a sliding stroke caused by the rotation of the cam 33, so that the transmission member 35 reciprocates in the front-rear direction with the total stroke L1 + L2. Since the driving member 36 is pushed by the transmission member 35 and swings around the pin 37, the driving member 36 is in a state where the large-diameter side of the cam 33 contacts the roller 34 as shown in FIG. Of the nozzle 1 is large, and therefore, the up / down stroke of the nozzle 1 is large. Also, as shown in FIG.
When the small diameter side of 33 is in contact with the roller 34, the up / down stroke of the nozzle 1 is small. Therefore, by adjusting the rotation angle of the cam 33, the vertical stroke of the nozzle 1 can be adjusted. Thus, the first cam 26 and the first cam 26
The transmission members 28 and 29 constitute a first driving device 55 of the driving member 36, and the nozzle 1 is driven by the driving device 55 to move up and down with a constant stroke. Further, the second cam 33 and the second transmission member 35 constitute a second driving device 56, and the second driving device 56 changes the rotation angle of the cam 33 so that the nozzle 1 It is a device for adjusting the lifting stroke that can adjust the stroke.

FIG. 6 is a graph showing the relationship between the vertical speed V of the nozzle 1, the stroke S, and the time t, where t1 is the first cam 26.
, T2 is when the rotation of the second cam 33 is started, t3 is when the rotation of the cam 33 is stopped, and t4 is when the rotation of the cam 26 is stopped. S1 and S2 are vertical strokes by the respective cams 26 and 33. As is clear from this figure, first the first cam
26 starts rotating and the nozzle 1 starts lowering, and then the second cam 33 starts rotating. Next, when the nozzle 1 approaches the target height, the second cam 33 stops rotating. When the nozzle 1 further descends and reaches the target height, the first
Of the cam 26 also stops rotating. Therefore, during the time (t2 to t3) during which both the cams 26 and 33 rotate together, the nozzle 1 moves the two cams 26 and 3 together.
3 descends at a high speed with the sum of the descending speeds V1 + V2, but immediately before landing on the electronic component P (t3 to t4), the first cam 26
With only rotation, it descends slowly. In this case, the total stroke S1 + S2 can be changed by adjusting the rotation speed of the cam 33 as described with reference to FIG. Therefore, if the data of the thickness of the electronic component P mounted on the board 14 is stored in the control device 50 in advance, and the pulse motor M2 is controlled based on this data to adjust the rotation angle of the cam 33, The nozzle 1 can be moved up and down by a stroke. In addition, in the time t3 to t4,
The slope of the descending speed is gentle, which means that the electronic component P can be softly landed on the substrate 14 at a low speed, and the nozzle 1 can be softly landed on the upper surface of the electronic component P on the wafer 15. Means that you can
Also, the gradient of the sum speed V1 + V2 in the middle time t2 to t3 is steep, which means that the nozzle 1 can move up and down at a high speed by increasing the intermediate speed, thereby increasing the mounting speed. It is desirable to change the up / down stroke of the nozzle each time for each electronic component. For example, the second stroke is set so that an average stroke corresponding to the average value of the thickness of the electronic components mounted on the board is obtained. The rotation angle of the cam 33 may be set.

(Effects of the Invention) According to the present invention, the up / down stroke of the nozzle can be freely adjusted according to the thickness of the electronic component by raising / lowering the nozzle using the first cam and the second cam. In addition to increasing the mounting speed by increasing the intermediate speed when the nozzle descends, the lowering speed when the nozzle lands on the upper surface of the electronic component or when the electronic component lands on the board is reduced, The applied impact is suppressed as much as possible, and damage to electronic components due to impact during landing can be eliminated.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a front view of a main part of an electronic component mounting apparatus, FIGS. 2 and 3 are perspective views and side views of an elevating apparatus, and FIG. FIG. 5, FIG. 5 is a partial plan view, FIG. 6 is a graph, FIGS. 7 and 8 are side views of the conventional device, and FIG. 9 is a graph. 1 Nozzle 26 First cam 28, 29 First transmission member 33 Second cam 35 Second transmission member 36 Driving member 50 Control device 52 Elevating Shaft M2: Motor P: Electronic components

Claims (2)

(57) [Claims] An elevating shaft for elevating and lowering a nozzle for sucking an electronic component, a driving member for elevating and lowering the elevating shaft, a first cam driven by a first motor, and a second cam.
A second cam driven by a first motor, a first transmission member for changing the position of the second cam in conjunction with the movement of the first cam, and the elevating shaft in association with the movement of the second cam A second transmission member for driving the driving member so as to raise and lower, and a control device for storing data of the thickness of the electronic component mounted on the substrate and controlling the second motor based on the data An electronic component mounting apparatus comprising: 2. A method of mounting an electronic component, wherein a first cam driven by a first motor and a second cam driven by a second motor raise and lower a nozzle for vacuum-sucking the electronic component. By driving the first cam and the second cam at the same time, the nozzle is lowered at a high speed. When the nozzle approaches the target height, the driving of the second cam is stopped and the second cam is stopped. By driving the first cam, the nozzle is lowered at a low speed to a target height, and the driving amount of the first cam and / or the second cam is controlled by a control device according to the thickness of the electronic component. An electronic component mounting method, characterized in that: