The present invention relates to a biaxial drive mechanism including an elevation axis and a die bonder using the biaxial drive mechanism and a die bonder operating method, and more particularly, to a highly reliable biaxial drive mechanism including an elevation axis and a highly reliable die bonder using the biaxial drive mechanism and a die bonder operating method.
A die bonder, which is one of semiconductor manufacturing devices, performs bonding of a semiconductor chip (die) to a substrate such as a lead frame. In the die bonder, a bonding head vacuum-sucks a die, then moves upward, then horizontally moves, then moves downward, and bonds the die to the substrate, at a high speed. In such case, a part for up and down movement is an elevation (Z) drive axis.
Recently, there is an increasing need for high-accuracy and high-speed die bonder, and particularly, there is an increasing need for high-speed bonding head as the heart of bonding.
As a conventional bonding head driving method, driving a ball screw with a servo motor is known (Japanese Published Unexamined Patent Application No. 2004-263825).
However, in the method of driving a ball screw with a servo motor, high-speed driving is limited. Accordingly, driving with a linear motor appropriate to high speed driving is studied. When a linear motor driving is merely adopted, the elevation axis can be easily manually-operated upon loss of power. As shown in
Accordingly, the present invention has been made in consideration of the above situation, and provides a highly reliable biaxial drive mechanism including an elevation axis and a highly reliable die bonder using the biaxial drive mechanism and a die bonder operating method capable of preventing fall of elevation axis of a linear motor upon loss of power.
To attain the above-described object, the present invention has at least the following features.
According to the present invention, the first feature of the present invention is a biaxial drive mechanism comprising: a handling part; a biaxial drive axes provided with a first linear motor unit having a first movable part that moves up and down the handling part along a first linear guide and a first stationary part, and a second linear motor unit having a second movable part that moves the handling part in a horizontal direction vertical to a direction of up and down movement and a second stationary part; a main power source that supplies a power source to the biaxial drive axes; and an elevation axis fall prevention unit that prevents fall of a movable part of a handling part upon loss of power at the main power source.
Further, the second feature of the present invention is that the biaxial drive axes has: a connecting part that connects the first movable part via the first linear guide and connects the second movable part directly or indirectly; a second linear guide that moves the first movable part, the second movable part and the connecting part integrally in the horizontal direction; and a support body that fixes the first stationary part and the second stationary part with a predetermined length in parallel to each other in the horizontal direction.
Further, the third feature of the present invention is that the biaxial drive axes has a third linear guide that fixes the first linear motor unit to the second movable part, and guides movement of the first linear motor unit in the horizontal direction.
Further, the fourth feature of the present invention is that the elevation axis fall prevention unit has: a stopper provided on a first movable body to move along with the first movable part; and a support drive part that supports the stopper in a predetermined position upon loss of power.
Further, the fifth feature of the present invention is that the support drive part is provided on the first stationary part, otherwise, the support drive part is provided on both end sides of the second stationary part or other stationary part around the second stationary part.
Further, the sixth feature of the present invention is that the support drive part is a solenoid having a bar to be able to protrude in accordance with presence/absence of power source or an air cylinder having a cylinder rod.
Further, the seventh feature of the present invention is that a supporting operation to support in the predetermined position is performed with another power source provided in addition to the main power source.
Further, the eighth feature of the present invention is that a controller that moves up the first movable part or maintains the first movable part in its current status with another power source provided in addition to the main power source upon loss of power is provided.
Further, the ninth feature of the present invention is that the biaxial drive mechanism in the first to eighth features is provided, and the handling part performs processing on a substrate.
Further, the tenth feature of the present invention is that the handling part is a bonding head that picks up a die from a wafer and bonds the die to the substrate, or a needle that applies a die adhesive to the substrate.
Further, the eleventh feature of the present invention is comprising: providing a main power source; a step of moving up a bonding head with a linear motor unit by supply of a main power source to pick up a die and bond the die to a substrate; and a fall prevention step of upon loss of power at the main power source, preventing fall of the bonding head.
In accordance with the present invention as described above, it is possible to provide a highly reliable biaxial drive mechanism including an elevation axis and a highly reliable die bonder using the biaxial drive mechanism and a die bonder operating method capable of preventing fall of elevation axis of a linear motor upon loss of power.
The above and other object, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings wherein:
Hereinbelow, preferred embodiments of the present invention will now be described in accordance with the accompanying drawings.
The wafer supply unit 1 has a wafer cassette lifter 11 and a pickup device 12. The wafer cassette lifter 11, having a wafer cassette (not shown) filled with wafer rings, sequentially supplies the wafer rings to the pickup device 12. The pickup device 12 moves the wafer ring so as to pick up a desired die from the wafer ring.
The work supply-conveyance unit 2 has a stack loader 21, a frame feeder 22 and an unloader 23. The work supply-conveyance unit 2 conveys a work (a substrate such as a lead frame) in an arrow direction. The stack loader 21 supplies a work, to which die is bonded, to the frame feeder 22. The frame feeder 22 conveys the work via two processing positions on the frame feeder 22 to the unloader 23. The unloader 23 stores the conveyed work.
The die bonding unit 3 has a preform unit (die paste applicator) 31 and a bonding head unit 32. The preform unit 31 applies a die adhesive to the work conveyed with the frame feeder 22 such as a lead frame with a needle. The bonding head unit 32 picks up the die from the pickup device 12 then moves upward, and horizontally moves the die to a bonding point above the frame feeder 22. Then the bonding head 32 moves down the die at the bonding point, and bonds the die to the work on which the die adhesive is applied.
The bonding head unit 32 has a ZY drive axes 60 to elevate the bonding head 35 (see
The power source unit 9 has a main power source 91 used in normal packaging processing and another battery 92 as a power source different from the main power source, necessary for prevention of fall of an elevation axis to be described later in detail.
First, the ZY drive axes 60 including the elevation axis according to the first embodiment as a feature of the present invention will be described using the drawings.
The ZY drive axes 60 according to the first embodiment has a Y drive axis 40, a Z drive axis 50, a connecting part 61 to connect a Y axis movable part 41 of the Y drive axis 40 and a Z axis movable part 51 of the Z drive axis 50, the bonding head 35 as a handling part, an elevation axis fall prevention unit 80 to prevent fall of the bonding head 35 upon loss of power, and an L-shaped support body 62 to support the entire ZY drive axes 60. Note that for assistance of understanding of the following explanation, a part fixed to the support body 62 is diagonally hatched, while a part to move integrally with the Y axis movable part 41, the X axis movable part 51 and the connecting part 61 are represented in outline. Further, the support body 62 has an upper support body 62a, a side support body 62b and a lower support body 62c.
The Y drive axis 40 has a C-shaped Y axis stationary part 42 having upper and lower stationary electromagnets 47u and 47d in which a large number of N pole and S pole electromagnets are alternately arrayed in the Y direction (hereinafter, when the electromagnets are generally referred to or any position is not designated, simply denoted by “47”), the Y axis movable part 41, having at least a pair of N pole and S pole electromagnets in the array direction, which is inserted in a C-shaped concave part and moved in the concave part, the connecting part 61 to support the Y axis movable part 41, and a Y axis guide part 44 which is fixed to the connecting part 61, and which has a Y axis linear guide 43 provided between the Y axis guide part and the lower support body 62c. The Y axis stationary part 42 is provided over approximately the whole area of the Y drive axis 40 indicated with a broken line in
As in the case of the Y drive axis 40, the Z drive axis 50 has a U-shaped Z axis stationary part 52 having right and left stationary electromagnets 57h and 57m in which a large number of N pole and S pole electromagnets are alternately arrayed in the Z direction (see
The Z axis movable part 51 is connected via the connecting part 61 to the Y axis movable part 41. When the Y axis movable part 41 horizontally moves in the Y direction, the Z axis movable part 51 also horizontally moves in the Y direction. It is necessary to provide N pole and S pole electromagnets in at least moving destination predetermined positions, e.g., a bonding region and a pickup region, such that the Z axis movable part 51 (bonding head 35) moves up and down. Note that a part to move up and down integrally with the Z axis movable part 51 is referred to as a Z axis movable body.
Next, the elevation axis fall prevention unit 80 according to the first embodiment as one of the characteristic features of the present invention will be described with reference to
The elevation axis fall prevention unit 80 according to the first embodiment has a stopper 81 fixed to the linear slider 53b to move up/down the bonding head 35, a pusher solenoid 82 as a support drive part fixed to the connecting part 61 as shown in
In the elevation axis fall prevention unit 80 having the above structure, the controller 7 detects loss of the main power source 91 upon loss of power, connects the other power source 91 to the pusher solenoid 82 while the power source is maintained with a capacitor or the like, and supplies the power source.
As a result, as shown in
According to the above-described first embodiment of the elevation axis fall prevention unit 80 of the present invention, upon loss of power at the main power source 91, it is possible to activate the pusher solenoid with another power source so as to prevent fall of the bonding head having the elevation axis of the linear motor.
As a result, it is possible to prevent breakage of the bonding head and the substrate.
Further, according to the above-described first embodiment of the ZY drive axes 60 in the invention, the Z axis stationary part 52 is provided in approximately the whole region, but the Z axis stationary part 52 is a heavy body and the Z axis stationary part 52 itself does not move. Accordingly, the load on the movement in the Y direction is greatly reduced, and it is possible to realize a high-speed elevation axis without increment in torque on a horizontal drive axis.
Next,
In a ZY drive axes 60A according to the second embodiment, a Z drive axis 50A is basically different from the ZY drive axes 60 according to the first embodiment. In the ZY drive axes 60 according to the first embodiment, the Z axis stationary part 52 of the Z drive axis 50 as an elevation axis is provided in the whole region of the moving range as in the case of the Y axis stationary part 42. The Z axis movable part 51 moves integrally with the Y axis movable part 41.
On the other hand, in the Z drive axis 50A according to the second embodiment, Z axis stationary part 52A and the Z axis movable part 51A move integrally with the Y axis movable part 41A in an arrow C direction in
The ZY drive axes 60A according to the second embodiment has the Y drive axis 40A, the Z drive axis 50A, the bonding head 35 as a handling part, an elevation axis fall prevention unit 80A to prevent fall of the bonding head 35 upon loss of power, and the support body 62 to support these elements.
As in the case of the first embodiment, the Y drive axis 40A has the C-shaped Y axis stationary part 42 which is fixed to the support body 62 and which has an opening 42a on the front side, and the Y axis movable part 41 which is inserted from the opening 42a in the concave part of the Y axis stationary part 42 and which moves in the concave part. The Y axis stationary part 42 is provided over approximately the whole region of the Y drive axis 40A indicated with a broken line in
As in the case of the Y drive axis 40A, the Z drive axis 50A has the C-shaped Z axis stationary part 52, the Z axis movable part 51 which is inserted in the C-shaped concave part and which moves in the concave part, a connecting part 54 to connect the Z axis movable part 51 and the bonding head 35, the Z axis linear guide 53 to guide up and down movement of the bonding head 35 in accordance with up and down movement of the Z axis movable part 51A, a holding body 55 to fix and hold these elements, and the Y axis linear guide 43 to guide the entire horizontal movement of the holding body 55, i.e. the Z drive axis 50A in accordance with the horizontal movement of the Y axis movable part 41 in the Y direction. The Z axis linear guide 53 has linear rails 53a fixed to the holding body 55, and a linear slider 53b which is fixed with the connecting part 54 and which moves up and down above the linear rails 53a. Further, the Y axis linear guide 43 has a linear rail 43a fixed with the support body 62 and the linear slider 43b to horizontally move on the linear rail 43a. Note that as in the case of the first embodiment 60 of the ZY drive axes, a part which moves integrally with the Z axis movable part 51 will be referred to as a “Z axis movable body”.
Next, the elevation axis fall prevention unit 80A according to the second embodiment as one of the characteristic features of the present invention will be described. The elevation axis fall prevention unit 80A has the stopper 81 fixed to the connecting part 54, a pull solenoid 84, fixed to the bottom of the holding body 55 and supplied with power from the main power source, which always pulls a pull bar 84a, a spring 85 fixed to the bottom of the holding body 55, and an actuation bar 86 with one end connected to the pull bar 84a and the other end connected to the spring 85. In the present embodiment, the support drive part has the pull solenoid 84, the spring 85 and the actuation bar 86. Note that the pull solenoid 84 is fixed to a bottom 55a of the holding body 55, and a supporting point 86a of the actuation bar 86 is fixed to the Y axis movable part 52.
In the elevation axis fall prevention unit 80A having the above structure, upon loss of power as shown in
According to the above-described second embodiment of the elevation axis fall prevention unit, upon loss of power at the main power source 91, it is possible to actuate the pull solenoid even without another power source and prevent fall of the bonding head having an elevation axis of a linear motor.
As a result, also in the second embodiment of the elevation axis fall prevention unit, it is possible to prevent breakage of the bonding head and the substrate.
In the above-described first and second embodiments, the pusher solenoid 82 and the pull solenoid 84 are arranged below the stopper 81, however, as shown in
Further, the position of the stopper 81 is not limited to the positions shown in
Next, an elevation axis fall prevention unit 80B according to a third embodiment as one of the characteristic feature of the present invention will be described with reference to
The elevation axis fall prevention unit 80B has a hollow case 181 having a ring-shaped hollow part with one end fixed to the Z axis stationary part 52 and with the inner periphery of the other end opened, an incombustible elastic body (e.g. rubber) 182 provided at least in the ring-shaped hollow part, a shape memory alloy 184 provided on the periphery of the elastic body 182, and a brake rod 185 as a projection part provided on the upper side of the bonding head 35. Note that as the projection part, a suction nozzle 35a provided at the end of the bonding head 35 in place of the brake rod may be used.
In the shape memory alloy 184, when power is supplied from the main power source 91 and an electric current flows through the shape memory alloy, a shape to maintain the elastic body 182 away from the brake rod 185 as shown in
In the above-described elevation axis fall prevention unit 80B according to the third embodiment, similar advantages to those in the first and second embodiments can be obtained.
Next, an elevation axis fall prevention unit 80C according to a fourth embodiment as one of the characteristic features of the present invention will be described with reference to
The elevation axis fall prevention unit 80C in the fourth embodiment has a spring 186, an electromagnet 187, a support drive part with one end fixed to the spring 186 while the other end provided with an actuation plate 188 as an actuation part attracted to the electromagnet 187 and a guide rod 189 to guide up and down movement of the actuation plate 188 along with the Z axis stationary part 52, and the stopper 81.
When power is supplied from the main power source 91 and the electric current flows through the shape memory alloy, the actuation plate 188 is attracted to the electromagnet 187 as shown in
In the above-described elevation axis fall prevention unit 80B in the fourth embodiment, similar advantages to those in the first to third embodiments can be obtained.
Next, an elevation axis fall prevention unit 80D according to a fifth embodiment as one of the characteristic features of the present invention will be described with reference to
The elevation axis fall prevention unit 80D is fixed to the Y axis fixing unit or the support body 62 or a fixing part around these parts in positions E or F shown in
As shown in
As described above, the elevation axis fall prevention unit 80D according to the fifth embodiment, different from the first to fourth embodiments, is provided not on the Z drive parts 40 and 40A but on the Y axis fixing part or the support body 62 or a fixing part around these parts. Further, as the actuation of the actuation rod 281, the methods shown in the second to fourth embodiments are applicable.
According to the above-described elevation axis fall prevention unit 80D according to the fifth embodiment, as the elevation axis fall prevention unit is not provided in the Z drive parts 40 and 40A, the structure of the Z drive part can be simplified.
Further, according to the above-described elevation axis fall prevention unit 80D according to the fifth embodiment, fall of the bonding head 35 can be prevented as in the case of the other embodiments.
Finally, an elevation axis fall prevention unit 80E according to a sixth embodiment as one of the characteristic features of the present invention will be described.
In the elevation axis fall prevention unit 80E according to the sixth embodiment, upon loss of power, a controller 9 controls e.g. the stationary electromagnet 57 shown in
According to the sixth embodiment of the elevation axis fall prevention unit, it is possible to prevent fall of the bonding head 35 without any new mechanism other than the other power source 92.
In the above description, the bonding head is used as a handling part. Basically, the bonding head is applicable to a handling part requiring a biaxial drive mechanism having an elevation axis. For example, in a die bonder, it is applicable to a needle to apply a die adhesive to a substrate.
The embodiments of the present invention have been described as above, however, various alternatives, modifications and equivalents can be made by those skilled in the art based on the above description, and it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents within the spirit and scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-156661 | Jul 2011 | JP | national |