WO1998052059A1

WO1998052059A1 - Circuit handling method and apparatus

Info

Publication number: WO1998052059A1
Application number: PCT/SE1998/000853
Authority: WO
Inventors: Anders Gustafsson
Original assignee: Cetelab Ab
Priority date: 1997-05-16
Filing date: 1998-05-08
Publication date: 1998-11-19
Also published as: SE9701849D0; AU7679798A; SE9701849L; SE509367C2

Abstract

Chips are fed in abutting relationship in a feeding direction; movement of a first chip is blocked in a first feeding position; a second chip is arrested; the first chip is released to be moved a small distance in the feeding direction and then blocked in a second feeding position; the first chip is displaced laterally to a treating position, treated there and returned to the second feeding position; the first chip is then released and discharged; and arrestment of the second chip is inhibited to allow it being moved to the first feeding position. An apparatus for handling chips includes chip feeding means (18), blocking means (22), arresting means (16), first releasing means (23'), second blocking means (23), lateral displacement means (15, 26) for bringing a chip to a treating position offset from the feeding direction and back to the second position, and second releasing means (21) for discharging a treated chip.

Description

CIRCUIT HANDLING METHOD AND APPARATUS

The present invention concerns a method and an apparatus for handling a plurality of integrated circuits (chips) .

More specifically, the present invention concerns the handling of chips in connection with operations such as programming and testing of chips, hereinafter referred to as treating. Such handling of a plurality of chips has traditionally been carried out by manually transferring an individual chip to an electronic treating station, bringing the legs of the chip into contacting position with corresponding terminals of a treating transmitter, starting the treating sequence, and, after completion of the treating sequence, removing the treated chip from the treating station. Even if such station is capable of simultaneously treating several chips, costly manual handling of the chips is still involved. Also, manual handling exposes the chips to the risk of electrostatic damage (ESD) .

In large scale operations complicated and expensive machines employing handling robots have previously been used.

US-A- , 315, 705 discloses a wafer processing system including an apparatus for handling and treating silicon wafers. Wafers are automatically sequenced through the apparatus. A shuttle with back and forth movement has an upper -slide and a lower slide, the upper slide being spaced from the top of the lower slide a parallel distance greater than a wafer thickness. Wafers are stacked on top of each other in a supply magazine. First the shuttle is retracted to receive a first wafer from the supply magazine and then advanced to bring it along the upper slide to center it over a rotating chuck. The chuck is moved up to pick up the first wafer from the upper slide. Then the shuttle is retracted to allow processing of the first wafer on the chuck and to receive another, second wafer on the upper slide from the magazine. The chuck is then moved down to locate the treated, first wafer on a level even with the lower slide. The shuttle is advanced again to center the second wafer on the upper slide over the chuck, and concurrently the chuck is further lowered to place the treated wafer on the lower slide. Then, the treated wafer is discharged along the lower slide.

It can be seen that the operating sequence of this prior art apparatus is rather complicated and that its various moveable components require a plurality of operating means and control means therefor for positioning the chuck at its different levels and to advance and retract the shuttle.

The present invention has as its objects to provide a method and an apparatus for handling a plurality of chips without the need of manual handling of the chips. Further, the apparatus shall be of simple construction and relatively cheap, and all its operations shall be performed with a minimum of driving means and control means therefor.

In achieving these objects, the present invention proposes a method of handling a plurality of chips including the steps of feeding a row of said chips in abutting relationship in a feeding direction along a first plane; blocking movement of a first of said chips in a first feeding position; arresting a second of said chips; releasing said first chip to allow it moving a small distance in said feeding direction along said first plane; blocking movement of said first chip in a second feeding position; displacing said first chip laterally in relation to said feeding direction to a treating position in a second plane; treating said first chip in said treating position; returning said first chip to said second feeding position in said first plane; releasing said first chip and discharging it along said first plane; inhibiting arrestment of said second of said chips to allow it being moved along said first plane to said first feeding position; and arresting a third of said chips; etc.

In achieving the objects stated, the present invention also proposes an apparatus for handling a plurality of integrated circuits (chips), including feeding means for feeding a row of individual chips in a feeding direction along a first plane, first blocking means for blocking movement in said feeding direction of a first chip of said row in a first feed position, arresting means for arresting a second chip of said row in a position abutting said first chip, first releasing means for releasing said first chip to allow it moving a small increment in said feeding direction along said first plane, second blocking means for blocking said first chip in a second feed position spaced from said second chip, lateral displacement means for bringing said first chip from said second position to a treating position located in a second plane offset from said first plane and back to said second position, and second releasing means for releasing said first chip in its treated state to allow it being discharged from the apparatus along said first plane.

The method and the apparatus according to the present invention will now be described, reference being made to a non-limiting embodiment of an apparatus for carrying out the method shown on the annexed drawings, wherein:

Fig. 1 is a partly sectioned side view of the apparatus; - Fig. 2 is portion II of Fig. 1 at an enlarged scale; Fig. 3 is a section through the apparatus taken along line III-III in Fig. 2 and showing an axial view of a first cam disc and associated arresting means; Fig. 4 is a section through the apparatus taken along line IV-IV in Fig. 2 and showing an axial view of a second cam disc and associated lateral displacement means; - Fig. 5 is a section through the apparatus taken along line V-V in Fig. 2 and showing an axial view of a third cam disc; and

Fig. 6 is a schematic representation showing side views and corresponding axial views of the cam discs in different rotational positions (A - F) .

In Figs. 1 and 2, 10 is a substantially vertically oriented machine stand. An electric motor 11 is carried by the stand 10 and has a shaft 12. A coaxial extension 13 of the shaft carries a first cam disc 14, a second cam disc 15 and a third cam disc 16. The shaft extension 13 is journalled in a bearing 17 connected to the machine stand 10.

A substantially vertical chip feeding chute 18 having a lower discharge end 19 is provided in the machine stand. A plurality of chips 20 can be seen within the feeding chute in Figs. 1 and 2.

The particular shapes of the cam discs appear particularly from Fig. 3 - 5.

The first cam disc 14 shown in Fig. 3 is an originally circular disc having a portion of its circumference cut off along a chord so as to provide a flat cam surface 21. The flat upper surface 22 of the disc is provided with a peripheral recess 23 starting with a step 23' and extending along approximately 270° of the circumference of the disc. The recess has a width (in the radial direction of the disc) substantially corresponding to the thickness of a chip 20. The second cam disc 15 shown in Fig. 4 is a circular disc eccentrically mounted on the shaft 13.

The third cam disc 16 is an originally circular disc having a portion of its circumference cut off along a chord so as to provide a flat cam surface 24 (Fig. 5) .

Opposite to the first cam disc 14 there is provided in the stand 11 an opening 25. Through this opening the first cam disc 14 extends into the feeding chute 20 with its un-cut peripheral portion a distance corresponding to the radial extension of the recess 23.

Immediately above the opening 25 there are two parallel openings 25a, 25b. A lateral displacement means in the shape of a U-shaped body 26 (Fig. 4) having a web portion 27 and two leg portions 28, 29 is slideably guided on rods 30 for radial movement relative to the shaft 13 such that the leg portions are introduceable into the feeding chute. The body 26 is spring loaded, as indicated by springs 31, for movement in a direction from the shaft towards the feeding chute, whereas movement in an opposite direction is controlled by the second cam disc 15. Fig. 4 shows the positions of the body 26 and the cam disc 15 where the leg portions 28, 29 are introduced through the openings 25a, 25b into the feeding chute 18.

A slot 32 opening in the feeding chute 18 is provided in the machine stand above the openings 25a, 25b. A lever 33 is swingably mounted in the slot about a pivot 34. One end of a spring 35 is supported by the machine stand and the other end by the lever 33 so as to urge a surface at the outer end of the lever towards the cam disc 16. Opposite its said surface, the lever is provided with an elastic cushion 36 of rubber or the like . The function of the apparatus will now be described with particular reference to Fig. 6, wherein the left hand part shows the cam discs from the side in rotational positions A - F, and the right hand part shows the mutual angular relation between the discs as well as the rotational positions of the jointly rotating discs in positions A - F. The common rotational axis of the cam discs is indicated with 13' and the rotational direction by a clock-wise directed arrow.

Starting in rotational position A (LOAD) , cam disc 14 is positioned such that its flat, unrecessed surface 22 is located in the path of movement of chips in the feeding chute 18 (not shown in Fig. 6) . In this position, movement of a first chip 20 A in the feeding direction is blocked by abutment with the flat surface 22 as seen in the left part of Fig. 6. Eccentric cam disc 15 is positioned in its "lowermost" position keeping the body 26 and its legs 28, 29 (not shown in Fig. 6) at a maximum distance from the feeding chute, whereas cam disc 16 is positioned to allow movement of chips along the feeding chute by keeping lever 33 in a position not engaging chips within the feeding chute with its cushion 36 shown in Fig. 5.

During further rotation through an angle of 45° to position B (BLOCK) , cam disc 16 moves the lever 33 towards the feeding chute such that its cushion 36 presses against a second chip 20:2 thereby preventing it from further movement along the feeding chute. The first chip 20:1 still bears on the unrecessed flat surface 22 of the first disc 14.

Position C (ADJUST) shows the situation after rotation through another 45°. Now, the step 23' starting the recessed peripheral portion 23 of the disc 14 is in a position to allow the first chip 20:1 to move a small distance further in the feeding direction, thereby leaving its abutting engagement with the second chip 20:2 which is still kept engaged by the cushion 36. The first chip is now free to be laterally moved to its treating position.

This is accomplished by further rotation of the cam discs through 90° to position D (PROGRAM) . Here it can be seen that the eccentric cam disc 15 is in its "upper" position allowing the legs 28, 29 (Fig. 4) to engage and press by the force of the springs 31 the contact legs 37 of the first chip 20:1 against non-shown terminals of a treating circuit.

After completion of the treating operation, the cam discs are rotated another 90° to position E (RELEASE) , where it can be seen that the eccentric cam disc 15 has allowed the first chip 20:1 to return to the feeding path resting on the recessed surface 23 close to the end thereof.

Another 45° of rotation brings the cam discs to position F (LET GO) , where the flat cut-off surface 21 of the cam disc 14 faces the feeding chute so that the programmed chip 20:1 is released from its engagement with the recessed surface 23 and may be discharged through the lower end 19 of the feeding chute.

After step F follows step A again, wherein the second chip 20:1 is released by the cushion 36 and is allowed to be moved into abutment with the unrecessed flat portion 22 of the cam disc 14.

Claims

1. A method of handling a plurality of integrated circuits (chips) including the steps of: - feeding a row of said chips in abutting relationship in a feeding direction along a first plane;

- blocking movement of a first of said chips in a first feeding position;

- arresting a second of said chips; - releasing said first chip to allow it moving a small distance in said feeding direction along said first plane;

- blocking movement of said first chip in a second feeding position;

- displacing said first chip laterally in relation to said feeding direction to a treating position in a second plane;

- treating said first chip in said treating position;

- returning said first chip to said second feeding position in said first plane;

- releasing said first chip and discharging it along said first plane;

- inhibiting arrestment of said second of said chips to allow it being moved along said first plane to said first feeding position; and

- arresting a third of said chips; etc.

2. A method according to claim 1, wherein said chips are gravitationally fed.

3. An apparatus for handling a plurality of integrated circuits (chips), including feeding means (18) for feeding a row of abutting individual chips (20) in a feeding direction along a first plane, first blocking means (22) for blocking movement in said feeding direction of a first chip (20:1) of said row in a first feeding position, arresting means (16) for arresting a second chip (20:2) of said row m a position abutting said first chip (20:1), first releasing means (23') for releasing said first chip to allow it moving a small increment in said feeding direction along said first plane, second blocking means (23) for blocking said first chip (20:1) in a second feeding position spaced from said second chip (20:2), lateral displacement means (15, 26) for bringing said first chip from said second position to a treating position located in a second plane offset from said first plane and back to said second position, and second releasing means (21) for releasing said first chip in its treated state to allow it being discharged from the apparatus along said first plane.

4. Apparatus according to claim 3, wherein said feeding means (18) is adapted to gravitationally feed said chips.

5. Apparatus according to claim 3, wherein said first blocking means (22), said arresting means (16), said first releasing means (23'), said second blocking means (23), said lateral displacement means (15, 26), and said second releasing means (21) are rotatable about a common rotational axis (13') .

6. Apparatus according to claim 5, wherein all said means are controlled by a common rotatable shaft (13), onto which they are mounted.

7. Apparatus according to claim 6, wherein said means are cam means .

8. Apparatus according to claim 7, wherein at least one of said means is an eccentric.

9. Apparatus according to claim 5, wherein all said means are driven by a common motor (11) .