1. Field of the Invention
The present invention relates to a horizontal axis drive mechanism, a two-axis drive mechanism, the two-axis including the lifting axis, and a die bonder.
2. Description of the Related Art
One of semiconductor manufacturing devices is a die bonder boding a semiconductor chip (die) to a substrate such as a lead frame and the like. In the die bonder, the die is vacuum-sucked by a bonding head, lifted at a high speed, moved horizontally, is lowered, and is mounted on the substrate. One that lifts and lowers then is a lifting (Z) drive section.
Recently, the demand of improving the accuracy and increasing the speed of the die bonder is strong, and particularly, the demand of increasing the speed of the bonding head that is the heart of bonding is strong.
In general, when the speed of a device is increased, vibration caused by a high speed moving object increases, and it becomes hard to obtain the accuracy aimed by the device due to the vibration.
As a technology coping with the demand, there is one described in JP-A No. 2000-003920. JP-A No. 2000-003920 discloses a technology in which a linear motor is used as a drive section of a semiconductor manufacturing device such as a die bonder, permanent magnets and coil side are moved in directions opposite to each other, vibration is reduced, and the permanent magnets side is returned to the original position by a damper.
As shown in
However, because the stator that moves is utilized as a counter weight, a phase shift δ is generated between the phase of the movable element and the magnet on the stator due to change of the position relative to the linear scale, and the driving force F1 of the motor drops.
In addition, JP-A No. 2000-003920 discloses a technology using the linear motor for a drive section in a flat plane, however a technology capable of increasing the speed and reducing the vibration in a two-axis drive mechanism using the linear motor also for the lifting axis is not disclosed. When only linear motor drive is employed, as shown in
Accordingly, the first object of the present invention is to provide a horizontal (Y) axis drive section of a linear motor light in weight, capable of reducing the vibration, and capable of increasing the speed.
Also, the second object of the present invention is to provide a two-axis drive mechanism including a lifting (Z) axis, capable of reducing the vibration in the horizontal axis and capable of increasing the speed in the lifting axis, and a die bonder using the two-axis drive mechanism.
In order to achieve the objects described above, the present invention has features described below at least.
The present invention is a horizontal axis drive mechanism including a first linear motor including a first fixed section and a first movable section fixing a load section and moving the load section in the horizontal direction, a support body supporting the first fixed section, a first linear guide arranged between the support body and the first fixed section and moving the first fixed section, a rotation conversion type counter including a rotating body rotatably supported by the support body and a converting means converting movement of the first fixed section in the horizontal direction into rotation of the rotating body, a linear sensor detecting the position of the first movable section in the horizontal direction relative to the support body, and a control section controlling the position of the first movable section in the horizontal direction based on output of the linear sensor.
Also, the present invention is a two-axis drive mechanism including the horizontal axis drive mechanism, a processing section, a second linear motor including a second movable section lifting and lowering the processing section along a second linear guide and a second fixed section fixed to the support body, a connecting section connecting the first movable section and the second movable section to each other via the first linear guide either directly or indirectly, a third linear guide moving the first movable section, the second movable section and the connecting section integrally in the vertical direction, and the load section integrated to the second movable section and loaded with a portion moving in the horizontal direction.
Further, the present invention is a die bonder including the two-axis drive mechanism in which a substrate is processed by the processing section.
According to the present invention, a Y (horizontal) axis drive section having horizontal (Y) axis driving section constitution of a linear motor light in weight, capable of reducing the vibration, and capable of increasing the speed can be provided.
Also, according to the present invention, a two-axis drive mechanism, the two-axis including a lifting (Z) axis, capable of reducing the vibration in the horizontal axis and capable of increasing the speed in the lifting axis and a die bonder using the same can be provided.
Below, embodiments of the present invention will be described based on the drawings.
The wafer supply section 1 includes a wafer cassette lifter 11 and a pickup device 12. The wafer cassette lifter 11 includes a wafer cassette (not illustrated) filled with wafer rings, and supplies the wafer ring to the pickup device 12 one by one. The pickup device 12 moves the wafer ring so that a desired die can be picked up from the wafer ring.
The workpiece supply/convey section 2 includes a stack loader 21, a frame feeder 22 and an unloader 23, and conveys the workpiece (the substrate such as the lead frame and the like) in the direction of the arrow. The stack loader 21 supplies the workpiece to which the die is adhered to the frame feeder 22. The frame feeder 22 conveys the workpiece to the unloader 23 via processing positions of two locations on the frame feeder 22. The unloader 23 stores the workpiece having been conveyed.
The die bonding section 3 includes a preform section (die paste coating device) 31 and a bonding head section 32. The preform section 31 coats the workpiece, for example the lead frame, having been conveyed by the frame feeder 22 with the die adhesive agent by a needle. The bonding head section 32 picks up the die from the pickup device 12, rises, and moves the die to a bonding point on the frame feeder 22. Also, the bonding head section 32 lowers the die at the bonding point, and bonds the die onto the workpiece coated with the die adhesive agent.
The bonding head section 32 includes a Z/Y-axis drive section 60 lifting and lowering a bonding head 35 (refer to
First, the problem occurring when the stator side is made a counter mechanism reducing the vibration and the phase shift as a linear motor shown in
When respective contact surfaces are assumed to be sufficiently smooth in such counter mechanism, the relational expression between the motion of the main drive section (movable element) LS and the counter section is;
[Expression 1]
F
1
=M
1
×a
1
=M2×a2 (1)
wherein M1: mass of the main drive section, a1: acceleration of the main drive section, a2: acceleration of the counter section, M2: mass of the counter section. In the counter mechanism, when the mass of the main drive section M1 and the acceleration of the main drive sectional are determined by the table specification, the acceleration of the counter section a2 can be controlled only by the mass of the counter section M2.
Next, with respect to the mass of the counter section M2 discussed in the problems to be solved, a case shown in
In this operation pattern, when the movable limit distance of the counter section is made Lm, the relationship of the movable limit distance of the counter section and the mass of the counter section M2 is as per the following expression from the relational expression (1).
[Expression 2]
M
2
=M
1
×a
1 (2)
When various values of the device with a conventional are substituted for the expression (2), in order to make Lm=several millimeters or less, the mass of the counter section M2 becomes 250-500 kg. Therefore, the mass of the counter section M2 is large, and it is impossible to mount the counter section on an actual machine.
In order to solve the problem, in the invention of the present application, as shown in the expression (3), energy of the linear motion of the reactive force F1 of the main drive section that becomes a cause of the vibration is converted into other kinetic energy, and the mass of the counter section M2 is reduced.
[Expression 3]
{reactive motion energy of main drive section}={kinetic energy of counter section}+{other kinetic energy} (3)
As the other kinetic energy, rotational motion energy, elastic energy of a spring and the like, thermal energy of a damper and the like, and etc. can be cited, however, in the invention of the present application, rotational motion energy is used which can achieve the movable limit distance of the counter section set in units of millimeters.
The Y-axis drive mechanism 40KA includes the Y-axis drive section 40 moving the processing section such as the bonding head 35 and the like that become the load section in the Y direction, and the rotation conversion type counter 100.
The Y-axis drive section 40 includes a Y-axis fixed section 42 of a squared C shape (refer to
Also, the Y-axis drive section 40 includes a Y-axis movable section 41 including at least one set of the N-pole and S-pole in the arraying direction and including a movable element inserted to a recess 42d of a squared C shape and moving inside the recess. A connection section 61 is connected to the Y-axis movable section 41 as the load section, and the connection section is tied to the processing section.
On the other hand, the rotation conversion type counter 100A is arranged at one end of the Y-axis drive section support body 62d. The rotation conversion type counter 100A includes a converting means converting the moment of inertia producing the moment of inertia described below and movement of the Y-axis drive section support body 62d in the horizontal direction into rotation of the rotating body. The converting means includes a ball screw 105 with one end side thereof being fitted in a nut 104, and with the other end side thereof being provided with a rotating body 101 fixed so that the rotation center of the ball screw agrees to the rotation center of the rotating body. The ball screw 105 is rotatably supported by a bearing 103 arranged in a flat section 105a on the other end side where the screw thread is not cut and a nut 104 fixed to a nut support section 106. The bearing 103 is arranged in a penetration section of the flat section 105a of a rotating body support body 102 fixed to the drive section support body 62d. The nut support section 106 is fixed to the Y-axis fixed section 42.
With such constitution, when the Y-axis movable section 41 constituting the main drive section moves to the direction of the arrow with the acceleration a1, the reactive force F1 is generated in the opposite direction in the Y-axis fixed section 42 constituting the counter section. By this reactive force F1, the Y-axis fixed section 42 is moved to the opposite direction, and the rotating body 101 is rotated via the ball screw 105. Also, the ball screw 105 may transmit rotation to the rotating body 101 via gears, pulleys and the like instead of directly contacting the rotating body.
In the direct motion type in which only the Y-axis fixed section 42 (counter section) reduced the vibration, the reactive force F1 received by the counter section was received only by the mass M2 of the Y-axis fixed section 42 (counter section), however, in the rotation conversion type, the reactive force F1 is received by the mass M2 of the counter section and the moment of inertia I of the rotating body, and the mass of the counter section can be reduced.
In this mechanism, the relationship between the main drive section and the counter section can be expressed by the expression below.
[Expression 4]
F
1
=M
1
×a
1=(M2+I)×a2 (4)
Here, I is the moment of inertia of the rotating body taking the ball screw into consideration. The mass M1 of the main drive section in
The point of the example 2 of the Y-axis drive mechanism 40K different from the example 1 is the rotation conversion type counter, and the Y-axis drive section is same with that of the example 1. The rotation conversion type counter 100B uses a link 203 instead of the ball screw 105 as a converting means, and converts the linear motion of the Y-axis fixed section 42 into the rotational motion of a rotating body 201. The rotating body 201 is rotatably supported by a rotating body support body 202 fixed to the drive section support body 62d so as to be parallel to the paper surface and rotatably supporting the rotating body 201.
Even in the example 2 of the rotation conversion type counter, the effect same to that of the example 1 can be exerted.
Next, a first embodiment 60C of the Z/Y-axis drive section 60 shown in
The Z/Y-axis drive section 60C that is the first embodiment includes a Y-axis drive section 40C, a Z drive section 50C, the connecting section 61 connecting the Y-axis movable section 41 of the Y-axis drive section 40C and a Z-axis movable section 51 of the Z drive section 50 to each other, and the support body 62 of lateral L-shape supporting all of them. The Z drive section 50C includes the bonding head 35 that is the processing section, and a rotation drive section 80 rotating the bonding head 35 around the Z-axis. Also, for the purpose of easy understanding of the description below, in
The Y-axis drive section 40C has the structure same to that of the Y-axis drive section 40 shown in
Also, the Y-axis drive section 40C includes the Y-axis movable section 41 including at least one set of electro-magnets of the N-pole and S-pole in the arraying direction, inserted to a recess of a squared C shape and moving inside the recess, and a linear sensor 71 detecting the position in the Y direction of the Y-axis movable section 41. The linear sensor 71 detects the position in the Y direction of the bonding head 35 described below moving along with the Y-axis movable section 41, and detects the position of the Y-axis movable section 41. The Y-axis drive section 40C can stably move the Y-axis movable section 41 in the Y direction by a Y-axis guide section 44 fixed to the connecting section 61 supporting the Y-axis movable section 41 and including a Y-axis linear guide 43 arranged between the connecting section and the lower support body 62c.
The Y-axis fixed section 42 is arranged over the substantially entire area of the Y-axis drive section 40 shown by a broken line of
In the present embodiment, the Y-axis fixed section linear guide 48 was arranged separately from the Y-axis linear guide 43. However, the Y-axis linear guide 43 may be used as the Y-axis fixed section linear guide 48 by arranging respective linear sliders 48b, 43b so as not to interfere with each other.
The Z drive section 50C includes a Z-axis fixed section 52 of an inverted U-shape, the Z-axis movable section 51 inserted to the recess of the inverted U-shape and moving inside the recess, and a Z-axis linear guide 53 guiding lifting and lowering of the Z-axis movable section 51. Similarly to the Y-axis drive section 40C, the Z-axis fixed section 52 includes right and left fixed magnet sections 57 (57h, 57m) in which a number of electro-magnets of the N pole and S pole are alternately arranged in the Z direction. The Z-axis movable section 51 includes at least one set of electro-magnets of the N pole and S pole in the upper part in the arraying direction of the Z-axis fixed section 52, is inserted to the recess of the inverted U-shape, and moves inside the recess. The Z-axis linear guide 53 is arranged between the Z-axis movable section 51 and the connecting section 61, and includes two linear rails 53a fixed to the connecting section 61 and extending in the Z direction, and a linear slider 53b fixed to the Z-axis movable section 51 and moving on the linear rails.
The Z-axis movable section 51 is tied with the Y-axis movable section 41 via the connecting section 61, and when the Y-axis movable section 41 moves in the Y direction, the Z-axis movable section 51 jointly moves in the Y direction. Also, at a predetermined position of the movement destination, the Z-axis movable section 51 (the bonding head 35) is lifted and lowered.
The bonding head 35 is arranged at the distal end of the Z-axis movable section 51 so as to be rotatable by a rotation drive section 80 via a gear 35b, and includes a collet 35a for sucking the die at own distal end. Also, the rotation drive section 80 controls the rotation attitude of the bonding head 35 by a motor 81 fixed to the Z-axis movable section 51 via gears 82, 35b.
Next, a third example 100C of the rotation conversion type counter 100 in the Y-axis drive section 60C will be described using
The rotation conversion type counter 100C is basically same to that of
It is a matter of course that the rotation conversion type counter 100C may be arranged on the upper side of the Y-axis fixed section 42 as shown in
In the first embodiment 60C of the Z/Y-axis drive section 60, the mass M1 of the main drive section is the total mass of the portion shown in white in
According to the Z/Y-axis drive section 60 described above, by arranging the rotation conversion type counter, the phase shift can be made within the moving range of the counter section, the driving force of the linear motor can be secured, the mass of the counter section can be reduced, and movement at a high speed in the Y direction becomes possible.
First, the Z/Y-axis drive section 60D will be described, and the rotation conversion type counter 100D will be described thereafter.
The points of the Z/Y-axis drive section 60D different from the Z/Y-axis drive section 60C that is the first embodiment will be described. The first point is that the Y-axis fixed section 42 is made of an I-shape long in the Z direction, and the Y-axis movable section 41 is arranged so as to be parallel to the Y-axis fixed section 42. The second point is that the fixed magnet section of the Y-axis is made 47 that is present on one side only. The third point is that a Y-axis movable section fixing section 45 is provided in a gap against the connecting section 61 to fix the Y-axis movable section 41. The fourth point is that the side support body 62d is shortened, and the Y-axis fixed section linear guide 48 allowing the Y-axis fixed section 42 to move is arranged on one side thereof.
The fifth point is that the Y-axis guide section 44 supporting the Y-axis liner guide 43 that allows movement in the Y direction of the Y-axis movable section 41 is relocated from the lower support body 62c to the upper support body 62a. The sixth point is that the Z-axis fixed section 52 is made of an I-shape instead of a U-shape, and the fixed magnet sections 57h, 57m are changed to the fixed magnet section 57 of one side only. The seventh point is that a linear guide 46 is arranged between the side support body 62b and the connecting section 61 in order to prevent swinging to the right and left of the movable integrated section in moving in the Y direction.
Also, the linear guide 46 stabilizing such movement may be arranged between the Y-axis fixed section 42 or the Z-axis fixed section 52 and the connecting section 61 in the first embodiment. Further, the second embodiment is different from the first embodiment in various points, however it is not necessary to differentiate all, although there are also different points interlockingly.
Other points are same to the Z/Y-axis drive section 60C that is the first embodiment.
On the other hand, the point of the rotation conversion type counter 100D different from the rotation conversion type counter 100A is that the rotation conversion type counter 100D is arranged on the Y-axis fixed section 42 of an I-shape. More specifically, the nut support section 106 shown in
In the second embodiment 60D of the Z/Y-axis drive section 60, the mass M1 of the main drive section is the total mass of the portion shown in white in
According to the Z/Y-axis drive section 60D described above, by arranging the rotation conversion type counter, the phase shift can be made within the moving range of the counter section, the drive force of the linear motor can be secured, the mass of the counter section can be reduced, and movement in the Y direction at a high speed becomes possible.
In the embodiment 60D of the Z/Y-axis drive section 60 described above, an example of the type of
According to the examples of the rotation conversion type counter described above, a Y (horizontal)-axis drive section having Y (horizontal)-axis drive section constitution of a linear motor light in weight, capable of reducing the vibration and capable of increasing the speed can be provided.
According to the examples of the rotation conversion type counter or the embodiments of the Z/Y-axis drive section described above, the speed in the lifting axis can be increased, the vibration in the Y (horizontal) axis can be reduced, and a two-axis drive mechanism, the two-axis including the Z (lifting) axis, and a die bonder including it can be provided.
Although the examples or the embodiments in relation with the present invention were described above, a variety of alternatives, modifications, or alterations are possible for a person with an ordinary skill in the art based on the above description, and the present invention is to include the variety of alternatives, modifications, or alterations within a scope not departing from the object thereof.
Number | Date | Country | Kind |
---|---|---|---|
2012-201729 | Sep 2012 | JP | national |