WO2008120876A1

WO2008120876A1 - Apparatus for transfer semiconductor packages

Info

Publication number: WO2008120876A1
Application number: PCT/KR2008/001489
Authority: WO
Inventors: Hyun Gyun Jung
Original assignee: Hanmi Semiconductor Co., Ltd.
Priority date: 2007-03-30
Filing date: 2008-03-17
Publication date: 2008-10-09
Also published as: KR20080088877A; TWI371075B; TW200845269A; KR100871670B1

Abstract

Disclosed is a semiconductor package transfer apparatus used for a semiconductor package manufacturing apparatus. The semiconductor package transfer apparatus includes a base block; a shaft guide hole formed in the base block in a vertical direction; an elevating shaft installed so as to slide vertically along the shaft guide hole; a picker fixedly connected to the elevating shaft and adapted to ascend/descend vertically by means of a vertical movement of the elevating shaft to fix or release a semiconductor package; an elevating drive unit for moving the elevating shaft vertically; and a pneumatic pressure supply unit for supplying pneumatic pressure to a lower end of the shaft guide hole at a predetermined pressure to pressurize a lower end of the elevating shaft upward and to prevent a backlash. The semiconductor package transfer apparatus has a sub¬ stantially simplified overall construction. The fact that a predetermined level of pneumatic pressure is applied to the lower end of the elevating shaft, which is adapted to elevate the picker, to pressurize the elevating shaft upward makes it possible to prevent the elevating drive unit from undergoing a backlash and to reduce the load on the elevating motor, which is adapted to drive the elevating shaft, without generating any moment.

Description

APPARATUS FOR TRANSFER SEMICONDUCTOR PACKAGES

Technical Field

[1] The present invention relates to an apparatus for transferring semiconductor packages. More particularly, the present invention relates to a semiconductor package transfer apparatus which is configured for a semiconductor package sawing and handling apparatus for sawing semiconductor packages on a strip package by package and storing the separate semiconductor packages on the tray of the unloading unit during semiconductor package manufacturing processes, and which is adapted to absorb the separate semiconductor packages by creating a vacuum and transfer them to the vision inspection position or unloading position. Background Art

[2] In general, semiconductor packages go through processes of attaching semiconductor chips (e.g. transistors, capacitors), on which highly integrated circuits are formed, to a semiconductor substrate made of silicon and molding resin on the upper surface of the semiconductor substrate. After the molding process, a BGA (Ball Grid Array) is attached to the lower surface of the semiconductor substrate as leads for electrical connection with the chips. After electric terminals (e.g. BGA) are formed on the semiconductor substrate, semiconductor packages of a basic type are completed. The resulting semiconductor substrate is referred to as a strip. The semiconductor packages of the strip undergo a singulation process, in which they are sawn into separate semiconductor packages by a sawing apparatus. After the singulation process is over, the semiconductor packages undergo cleaning and drying processes to remove alien substances from their surfaces. After the drying process, the semiconductor packages are transferred to a vision inspection apparatus, which determines whether they are acceptable or not. Based on the result of the inspection, the semiconductor packages are classified and stored in a tray.

[3] The series of processes of sawing the semiconductor packages on the strip package into separate semiconductor packages and storing them in the tray is conducted by a semiconductor package sawing and handling apparatus.

[4] The semiconductor package sawing and handling apparatus includes a strip loading unit for supplying a strip due for the sawing operation, a sawing unit for sawing the strip into separate semiconductor packages, and a semiconductor package transfer apparatus for transferring the separate semiconductor packages to the tray of the unloading unit.

[5] FIG. 1 shows the construction of a conventional semiconductor package transfer apparatus used for the above-mentioned semiconductor package sawing and handling apparatus. The conventional semiconductor package transfer apparatus includes a base block 1 installed on the upper portion of the apparatus and adapted to move horizontally along a guide frame; a plurality of elevating shafts 2 installed on the base block 1 and adapted to slide vertically; a plurality of elevating blocks 5 fixed to the lower end of respective elevating shafts 2; and a plurality of pickers 3 fixed to the front end of respective elevating blocks 5 and adapted to ascend/descend together with the elevating blocks 5 to absorb a semiconductor package by creating a vacuum.

[6] A rack gear 4a is formed in the vertical direction on one side of each elevating shaft 2, and meshes with a pinion gear 4b rotated by a motor 4c. The pinion gear 4b simultaneously meshes with two rack gears 4a between two adjacent elevating shafts 2. Therefore, as the pinion gear 4b is rotated by the motor 4c, one of the rack gears 4a meshing with the pinion gear 4c descends, while the other rack gear 4a ascends. In other words, the driving of the pinion gear 4b lifts one of both adjacent pickers 3 and lowers the other picker 3 so that the semiconductor package is absorbed by creating a vacuum or is placed in a desired position.

[7] As such, the pickers 3 ascend/descend a desired distance by the operation of the rack gears 4a and the pinion gears 4b. However, the operation of the rack and pinion gears 4a and 4b involves a backlash between them, which hinders the movement of the pickers to the exact desired height.

[8] In order to compensate for the tolerance resulting from the backlash, the prior art employs backlash shafts 6 installed behind the base block 1 adapted to slide vertically inside backlash shaft guide holes Ia. A constant level of pneumatic pressure is supplied to the upper end of the backlash shaft guide holes Ia via pneumatic lines 8a so that the pickers 3 receive constant downward force.

[9] In addition, the base block 1 is provided with emergency stop cylinders 7, the piston rods of which are adapted to slide vertically so that, in an emergency, the piston rods are lifted/lowered by the pneumatic pressure to return the pickers 3 to the initial height. More particularly, if the semiconductor package transfer apparatus stops functioning due to an unexpected power interruption, the piston rods are lowered by the pneumatic pressure supplied via overlying pneumatic lines 8b. Then, the piston rods compress and lower those of the pickers 3, which are in a higher position, and lift the other pickers 3 that are moving in the opposite direction in adjacent positions. The pickers 3 return to the initial height in this manner.

[10] If the pickers 3 are not moved to the initial positions in an emergency, pickers 3 on one side descend due to their own weight. If the operator manually moves the pickers 3, the bottommost picker 3 may collide with another underlying object and get damaged. In addition, when the power supply resumes, the pickers 3 may not be accurately positioned. In this case, it is impossible to correctly operate the pickers 3.

[11] However, the conventional semiconductor package transfer apparatus has the following problems.

[12] Firstly, the backlash shafts 6 are fixed to the elevating shafts 2 together with the pickers 3, and the weight always acts on the backlash shafts in the downward direction. Therefore, in the case of ascending pickers, the force to prevent a backlash acts as resistance. This increases the load on the motors 4c. In addition, the fact that the elevating shafts 2 and the backlash shafts 6 are not coaxial creates a rotational moment between both shafts. This further increases the load on the motors.

[13] Secondly, the emergency stop cylinders 7, which are separate from the elevating shafts 2 and the backlash shafts 6, and which are adapted to prevent the pickers from descending and to return them to the original positions in an emergency, complicate the construction of the semiconductor package transfer apparatus and increase its weight. As a result, a heavier load is applied to the driving unit for driving the semiconductor package transfer apparatus. Disclosure of Invention Technical Problem

[14] Therefore, the present invention has been made in view of the above-mentioned problems, and the present invention provides a semiconductor package transfer apparatus which has a simple structure, and which is adapted to apply anti-backlash force along the same axes as the elevating shafts to prevent any moment, thus minimizing the load on the motors.

[15] The present invention also provides a semiconductor package transfer apparatus adapted to prevent the pickers from descending due to their own weight in an emergency (e.g. unexpected interruption of power supplied to the apparatus) and maintain them at a predetermined height or higher so that any damage to the equipment is avoided. Technical Solution

[16] In accordance with an aspect of the present invention, there is provided a semiconductor package transfer apparatus including a base block; a shaft guide hole formed in the base block in a vertical direction; an elevating shaft installed so as to slide vertically along the shaft guide hole; a picker fixedly connected to the elevating shaft and adapted to ascend/descend vertically by means of a vertical movement of the elevating shaft to fix or release a semiconductor package; an elevating drive unit for moving the elevating shaft vertically; and a pneumatic pressure supply unit for supplying pneumatic pressure to a lower end of the shaft guide hole at a predetermined pressure to pressurize a lower end of the elevating shaft upward and to prevent a backlash.

[17] The semiconductor package transfer apparatus according to the present invention has a substantially simplified overall construction. The fact that a predetermined level of pneumatic pressure is applied to the lower ends of the elevating shafts, which are adapted to elevate the pickers, to pressurize the elevating shafts upward makes it possible to prevent the elevating drive unit from undergoing a backlash and to reduce the load on the elevating motors, which are adapted to drive the elevating shafts, without generating any moment.

[18] The supply of pneumatic pressure to the lower portions of the elevating shafts is not interrupted even in an emergency (i.e. unexpected interruption of power supplied to the semiconductor package transfer apparatus), and maintains the pickers at a predetermined height or higher (i.e. they do not descend due to their own weight). Therefore, if the semiconductor package transfer apparatus is moved in the case of an emergency, the pickers are prevented from colliding with other components of the apparatus and getting damaged.

Advantageous Effects

[19] As mentioned above, the semiconductor package transfer apparatus according to the present invention is advantageous in that, a predetermined level of pneumatic pressure is applied to the lower ends of the elevating shafts for elevating the pickers to pressurize the elevating shafts upward. This prevents a backlash and reduces the load on the elevating motors for driving the elevating shafts without generating any moment.

[20] In addition, the present invention simply relies on the application of pneumatic pressure to the lower ends of the elevating shafts, instead of using separate backlash shafts and stop cylinders as in the case of the prior art, to compensate for a backlash and cope with an emergency. This simplifies the overall construction of the semiconductor package transfer apparatus, and further reduces the load on the motors. Brief Description of the Drawings

[21] The foregoing and other objects, features, and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[22] FIG. 1 is a sectional view showing major parts of a conventional semiconductor package transfer apparatus;

[23] FIG. 2 is a front view showing the construction of a semiconductor package transfer apparatus according to an embodiment of the present invention;

[24] FIG. 3 is a sectional front view showing major parts of the semiconductor package transfer apparatus shown in FIG. 2; [25] FIG. 4 is a sectional lateral view of the semiconductor package transfer apparatus shown in FIG. 2;

[26] FIG. 5 is an enlarged view of part A shown in FIG. 4;

[27] FIG. 6 is a sectional lateral view of the semiconductor package transfer apparatus shown in FIG. 4 when the picker has ascended in an emergency; and

[28] FIGs. 7 and 8 are sectional lateral views showing the construction of a semiconductor package transfer apparatus according to another embodiment of the present invention. Mode for the Invention

[29] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[30] A semiconductor package transfer apparatus according to a first embodiment of the present invention will now be described with reference to FIGs. 2-6.

[31] Referring to FIGs. 2-4, the semiconductor package transfer apparatus according to the present invention has a guide block 10 installed on the upper portion of a semiconductor package sawing and handling apparatus and adapted to slide horizontally along a guide frame G.

[32] The base block 10 has a plurality of (eight, in this embodiment) shaft guide holes

11 extending in the vertical direction. Elevating shafts 20 are installed in respective shaft guide holes 11 and are adapted to slide vertically. The sliding shafts 20 are supported by guide bushings 22 installed on the upper and lower portions of the shaft guide holes 11, respectively, while being able to slide vertically. The upper portions of the elevating shafts 20 extend through the upper ends of the shaft guide holes 11 and protrude out of the base block 10.

[33] The elevating shafts 20 have rack gears 41, which mesh with pinion gears 42, respectively, so that the rack gears 41 are lifted or lowered by rotation of the pinion gears 42, which are rotated by elevating motors 43 installed behind the base block 10.

[34] The base block 10 has a plurality of pickers 30 installed in front of respective elevating shafts 20 and adapted to move vertically to absorb a semiconductor package by creating a vacuum. Each picker 30 includes rotatable blocks 31a and 31b installed on the upper and lower portions of the base block 10, respectively, and adapted to rotate about a vertical axis; a hollow ball spline 32 extending through respective rotatable blocks 31a and 31b vertically while being able to slide vertically relative to the rotatable blocks 31a and 31b; a absorption nozzle member 33 connected to the lower end of the ball spline 32 to absorb a semiconductor package by creating a vacuum; and a link member 35 integrally connecting the upper end of the ball spline 32 with that of the elevating shaft 20. [35] A following pulley 46 is fixedly coupled to the upper portion of the ball spline 32.

A plurality of (four, in this embodiment) picker rotating motors 45 are connected to the upper portion of the base block 10 together with driving pulleys 47, which are axially coupled to the picker rotating motors 45. Each driving pulley 47 is connected to both following pulleys 46 of two pickers 30 via a power transmission belt 48. Therefore, as the driving pulley 47 is rotated by the picker rotating motor 45, the power transmission belt 48 simultaneously rotates both pickers 30 by a predetermined angle about the vertical axis.

[36] Although not shown in the drawings, the ball spline 32 of each picker 30 has grooves positioned inside the rotatable blocks 31a and 31b, respectively, and elongated in the vertical direction. A plurality of balls are placed in the grooves so that the ball spline 32 cannot rotate relative to the rotatable blocks 31a and 31b, but slide in the vertically direction only. Therefore, when the elevating shafts 20 ascend/descend vertically, the ball splines 32 move upward/downward relative to the rotatable blocks 31a and 31b and vary the vertical position of the absorption nozzle members 33. When the picker rotating motors 45 are actuated to apply rotational force to the ball splines 32, the rotatable blocks 31 and 31b, which are connected to the ball splines 32, rotate relative to the base block 10 and adjust the angle of rotation of the absorption nozzle members 33.

[37] The base block 10 has a pneumatic pressure supply hole 52 formed in its lower portion. The pneumatic pressure supply hole 52 integrally extends from one side of the base block 10 to the other side, and communicates with one side of the lower end of each shaft guide hole 11. A pneumatic pressure line 51 is connected to an end of the pneumatic pressure supply hole 52 to supply external air at a predetermined pressure. A hollow cylindrical pneumatic pressure indraft member 55 is fixedly coupled to the lower end of each shaft guide hole 11, and is opened in the upward direction.

[38] As shown in detail in FIG. 5, each pneumatic pressure indraft member 55 has a hollow body 55 a, into which the lower end of the elevating shaft 20 is inserted while being able to slide vertically, and a plurality of airflow holes 55b extending through the body 55a so that air supplied into the shaft guide hole 11 via the pneumatic pressure supply hole 52 can flow into the body 55a. Although it has been assumed in the description of the present embodiment that four airflow holes 55b are formed at an interval of 90 in the circumferential direction, the number and interval can be varied as desired.

[39] The hollow portion of the body 55a has a diameter slightly larger than that of the elevating shaft 20 so that a fine gap exists between the inner peripheral surface of the body 55a and the outer surface of the elevating shaft 20.

[40] A first sealing member 56 of an O-ring type is installed below each pneumatic pressure indraft member 55, and is interposed between the outer peripheral surface of the pneumatic pressure indraft member 55 and the inner peripheral surface of the shaft guide hole 11 to maintain airtightness.

[41] Preferably, each lower guide bushing 22 also has a second sealing member 57 of an

O-ring type installed above it to prevent the leakage of air through the gap between the shaft guide hole 11 and the elevating shaft 20.

[42] The operation of the semiconductor package transfer package, which is constructed as mentioned above, will now be described.

[43] When a predetermined control signal is applied to the elevating motors 43 to actuate them, the pinion gears 42, which are axially coupled to the elevating motors 43, are rotated. Then, the rack gears 41 interwork with the pinion gears 42 so that the elevating shafts 20 slide vertically inside the shaft guide holes 11. The vertical movement of the elevating shafts 20 is followed by that of the pickers 30.

[44] Air is supplied to the pneumatic pressure supply hole 52 via the pneumatic pressure line 51 at a predetermined pressure. The air is directed into the lower end of each shaft guide hole 11, and flows into the body 55a of each pneumatic pressure indraft member 55 via the airflow holes 55b.

[45] As air is continuously supplied into the body 55a of each pneumatic pressure indraft member 55 at a predetermined pressure, the lower end of each elevating shaft 20 is forced upward. As a result, teeth of the rack and pinion gears 41 and 42, which drive the elevating shafts 20, are forced against each other. This prevents any backlash.

[46] Such upward pressurization of the elevating shafts 20 by the air flowing into the pneumatic pressure indraft members 55 is also advantageous in that, when the elevating shafts 20 are moved upward against the gravity, the load on the elevating motors 43 is alleviated.

[47] In addition, the supply of air through the pneumatic pressure line 51 is not interrupted even in an emergency (i.e. unexpected interruption of power supplied to the semiconductor package transfer apparatus). Therefore, as shown in FIG. 6, the lower ends of the elevating shafts 20 are continuously pressurized upward by the pneumatic pressure, and the pickers 30 move up to a predetermined position together with the elevating shafts 20. The emergency is properly handled in this manner.

[48] As such, pneumatic pressure is continuously supplied to the lower ends of the elevating shafts 20 during operation of the semiconductor package transfer apparatus according to the present invention so that any backlash is compensated for. In other words, anti-backlash force is applied along the same axes as the elevating shafts 20. Consequently, no moment is applied to the elevating shafts 20 and increases the load on the motors.

[49] In addition, application of pneumatic pressure to the lower ends of the elevating shafts 20 guarantees that the pickers 30 do not descend due to their own weight, even in an emergency, without using a separating apparatus for preventing the pickers 30 from descending in an emergency.

[50] The semiconductor package transfer apparatus according to the above-mentioned embodiment of the present invention has separate pneumatic pressure indraft members 55 coupled to the lower ends of the shaft guide holes 11 so that pneumatic pressure is applied inside the pneumatic pressure indraft members 55 to pressurize the elevating shafts 20 upward. However, it is also possible to pressurize the elevating shafts 20 upward without using separate pneumatic pressure indraft members. To this end, for example, the lower ends of the shaft guide holes 11 are closed and are integral with the base block 10 so that air can be injected through the lower ends of the shaft guide holes 11 to pressurize the elevating shafts 20 upward.

[51] FIGs. 7 and 8 show a semiconductor package transfer apparatus according to another embodiment of the present invention, the basic construction of which is similar to that according to the first embodiment described above.

[52] The difference between the first and second embodiment lies in the fact that, according to the latter, pneumatic pressure is supplied to the lower portions of the elevating shafts 20 to prevent a backlash. The construction of the pneumatic pressure supply unit for coping with an emergency also differs between them.

[53] More particularly, according to the second embodiment, the lower ends of the shaft guide holes 11 are closed, and first pneumatic pressure supply holes 151 are formed at a predetermined distance in the upward direction from the lower ends of the shaft guide holes 11 to communicate with the lower portions of the shaft guide holes 11. In addition, the base block 10 has an anti-backlash pneumatic pressure supply line 152 formed on one side. The anti-backlash pneumatic pressure supply line 152 is connected with one side of respective first pneumatic pressure supply holes 151 to supply air at a predetermined pressure and to pressurize the lower ends of the elevating shafts 20 when the semiconductor package transfer apparatus functions normally.

[54] Second pneumatic pressure supply holes 153 are formed on the bottommost portions of the shaft guide holes 11 to communicate with them. An emergency pneumatic pressure supply line 154 is connected to one side of the base block 10 to supply air at a predetermined pressure via the second pneumatic pressure supply holes 153 in an emergency.

[55] Pistons 155 are installed inside the lower ends of the shaft guide holes 11 and are adapted to move vertically. The pistons 155 are moved upward by the pneumatic pressure supplied via the second pneumatic pressure supply holes 153 to pressurize the lower ends of the elevating shafts 20.

[56] The semiconductor package transfer apparatus according to the second embodiment of the present invention is operated as follows: when the apparatus functions normally, a predetermined level of pneumatic pressure is supplied via the anti-backlash pneumatic pressure lines 152 to pressurize the lower ends of the elevating shafts 20 upward. This prevents a backlash.

[57] In an emergency, i.e. if the semiconductor package transfer apparatus stops functioning due to an unexpected power interruption, the supply of pneumatic pressure via the anti-backlash pneumatic pressure line 152 is interrupted. Then, air is supplied to the bottommost portions of the shaft guide holes 11 at a predetermined pressure via the emergency pneumatic pressure line 154 and the second pneumatic pressure supply holes 153. Then, the pistons 153 ascend and pressurize the lower portions of the elevating shafts 20. This prevents the elevating shafts 20 and the pickers 30, which are coupled to the elevating shafts 20, from descending.

[58] The second embodiment of the present invention also proposes that, as shown in

FIG. 8, the absorption nozzle member 133 of each picker 30 include a nozzle holder 1331 and a absorption nozzle 1332 adapted to easily attach to and detach from the nozzle holder 1331. This makes it possible to easily replace the absorption nozzle 1332 with one conforming to the type of the semiconductor package.

[59] More particularly, a slide member 1334 is installed outside an inserting/releasing groove 1333 of the nozzle holder 133 so as to slide vertically. A spring 1335 is installed between the slide member 1334 and the outer surface of the nozzle holder 1331 to elastically support the slide member 1334. A plurality of balls 1336 are installed on the lower end of the nozzle holder 1331, and are biased to the inside/ outside of the inserting/releasing groove 1333 by means of the contact with the slide member 1334.

[60] The absorption nozzle 1332 has a support groove 1337 formed on a part of its outer peripheral surface, which is inserted into the inserting/releasing groove 1333, in the circumferential direction so that the balls 1336 engage with the support grooves 1337 to be supported.

[61] Therefore, when the absorption nozzle 1332 is to be coupled to the nozzle holder

1331, the slide member 1334 is moved upward to free the balls 1336. Then, the upper portion of the absorption nozzle 1332 is inserted into the inserting/releasing groove 1333, and the slide member 1334 is released. As a result, the slide member 1334 descends due to its own weight and the elastic force from the spring 1335 until it contacts the outer surface of the balls 1336, which are pushed into the inserting/ releasing groove 1333. The balls 1336 are partially absorbed into the support groove 1337 of the absorption nozzle 1332, which is then rigidly fixed to the nozzle holder 1331.

[62] When the absorption nozzle 1332 is to be unfastened from the nozzle holder 1331, the user slides the slide member 1334 upward to free the balls 1336. Then, the absorption nozzle 1332 is pulled downward, and is easily separated form the nozzle holder 1331. Industrial Applicability

[63] The present invention is applicable not only to semiconductor package sawing and handling apparatuses for sawing a strip into semiconductor packages and storing them in a tray, but also to all types of semiconductor package transfer apparatuses used for apparatuses for manufacturing or handing semiconductor packages.

[64] Although several exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] A semiconductor package transfer apparatus for picking up a semiconductor package in a process position of a semiconductor package manufacturing apparatus to a different process position, the semiconductor package transfer apparatus comprising: a base block; a shaft guide hole formed in the base block in a vertical direction; an elevating shaft installed so as to slide vertically along the shaft guide hole; a picker fixedly connected to the elevating shaft and adapted to ascend/descend vertically by means of a vertical movement of the elevating shaft to fix or release a semiconductor package; an elevating drive unit for moving the elevating shaft vertically; and a pneumatic pressure supply unit for supplying air to a lower end of the shaft guide hole at a predetermined pressure to pressurize a lower end of the elevating shaft upward and to prevent a backlash of the elevating drive unit.

[2] The semiconductor package transfer apparatus as claimed in claim 1, wherein the pneumatic pressure supply unit comprises: an air supply hole formed on the base block to communicate with a lower portion of the shaft guide hole; a pneumatic pressure line connected to a side of the air supply hole to supply air at a predetermined pressure; and a pneumatic pressure indraft member fixedly coupled to the lower end of the shaft guide hole, the pneumatic pressure indraft member having a hollow body, an upper end of the body being open so that the lower end of the elevating shaft being inserted while being able to slide, and an airflow hole extending through the body so that air supplied into the shaft guide hole via the air supply hole flows into the body.

[3] The semiconductor package transfer apparatus as claimed in claim 2, further comprising a first sealing member interposed between an outer peripheral surface of the body of the pneumatic pressure indraft member and an inner peripheral surface of the shaft guide hole to maintain airtightness.

[4] The semiconductor package transfer apparatus as claimed in claim 1, wherein the elevating drive unit comprises a rack gear formed on the elevating shaft in the vertical direction, a pinion gear meshing with the rack gear, and a motor for rotating the pinion gear.

[5] The semiconductor package transfer apparatus as claimed in claim 1, further comprising at least one guide bushing coupled inside the shaft guide hole to guide a vertical movement of the elevating shaft, and a second sealing member installed above or below the guide bushing to maintain airtightness between the elevating shaft and the shaft guide hole.

[6] The semiconductor package transfer apparatus as claimed in claim 1, wherein the pneumatic pressure supply unit is adapted to supply a predetermined pressure to the lower end of the shaft guide hole and to pressurize the elevating shaft upward, when the semiconductor package transfer apparatus stops functioning due to an unexpected power interruption, so that the picker is prevented from descending.

[7] The semiconductor package transfer apparatus as claimed in claim 1, wherein the pneumatic pressure supply unit comprises: a first air supply hole formed on the base block to communicate with a lower portion of the shaft guide hole; an anti-backlash pneumatic pressure line connected to a side of the first air supply hole to supply air at a predetermined pressure and to pressurize the lower end of the elevating shaft when the semiconductor package transfer apparatus functions normally; a second air supply hole formed on the base block to communication with a bottommost portion of the shaft guide hole; an emergency pneumatic pressure supply line connected to a side of the second air supply hole to supply air to the second air supply hole at a predetermined pressure when the semiconductor package transfer apparatus stops functioning due to an unexpected power interruption; and a piston installed on the lower end of the shaft guide hole and adapted to slide vertically so that the piston is lifted by pneumatic pressure supplied from the second air supply hole to pressurize the lower end of the elevating shaft.