US3171436A - Transfer device - Google Patents

Description

March 1965 c. A. LOWELL TRANSFER DEVICE Filed March 5, 1962 United States Patent Office 3,171,435 Patented Mar. 2, 1965 3,171,436 TRANSFER DEVICE Charles A. Lowell, Reading, Pa., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Mar. 5, 1962, Ser. No. 177,661 3 Claims. (Cl. 137-604) This invention relates to transfer devices and particularly to a device for lifting elements, such as semiconductor wafers, at one area and transferring them to another area where they are released upon an article, such as a transistor header.

In the manufacture of semiconductor devices, a relatively small, thin wafer, consisting of a semiconductor material such as silicon or germanium, is placed upon a transistor header and subsequently bonded thereto. Various types of suction or vacuum devices are utilized for transporting the wafers from a pick-up area to the release area where the headers are located. Such devices, however, usually require the installation of complex vacuum and electrical systems which not only take up much space and are costly to build but also are difiicult to maintain. Further, the use of such devices is often restricted since the gaseous media employed might cause explosion as a result of a spark in the electrical system.

Accordingly, an object of this invention is a vacuum transfer device which is simple in design, safe to operate, inexpensive to construct, and easy to maintain.

Broadly, the inventive device includes a housing having a passage extending therethrough and communicating with a duct therein, the passage being connected to a source of compressed fluid. A valve extends into the passage in such a manner that when it is operated to one position, suction is created in the duct to lift the wafer, and when it is operated to another position, the compressed fluid flows through the duct to remove the wafer therefrom.

In a preferred embodiment, one end of the duct is connected to a needle, and the other end is perpendicularly disposed to and communicating with the passage. The valve is provided with a closure end portion extending Within the passage, the end portion having an upper and lower arcuate surface defined by a substantially linear surface. Cam means are provided for moving the valve vertically to various positions. At a first position the closure linear surface is parallel to the passage wall and perpendicular to the one end end of the duct to create a venturi effect for producing a suction therein causing the needle to lift the wafer. At a second position the closure bottom surface is disposed beneath the one end of the duct to block the passage and permit the fluid to pass through the duct to release the article from the needle. At a third position the closure upper surface is disposed over the one end of the duct to block said one end and passage thereby preventing any activity in the duct.

Other objects will be apparent and a fuller understanding of the invention may be had by referring to the following description of a specific embodiment thereof, taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a partial, schematic, sectional view of a trans fer device illustrating the device in its unoperated position;

FIG. 2 is a partial, schematic, sectional view illustrating the device in its wafer suction or vacuum pick-up position; and

FIG. 3 is a partial, schematic, sectional view illustrating the device in its wafer release position.

With reference to the drawing, the invention is incorporated in a transfer device having a head portion, generally referred to as 10, utilized for picking up a wafer 11 and transferring it to a header 12 where it is released thereon. The head portion includes a housing 13 having an air supply passage 14 vertically extending therethrough, the passage having a bend at 15 and extending horizontally to the outer surface 16 of housing 13. Air passage 14 is connected to a source of fluid 17, such as compressed air, by a tube 18.

A connecting duct 20, having a diameter smaller than air passage 14, is perpendicularly disposed to and extends partially within the air passage, the duct having a tapered, extending end portion 21. Duct 20 is provided with a 90 bend at 22 and extends vertically through the housing to communicate with a needle 23 disposed within a body portion 24 threadedly connected to a needle adjusting locking nut 25, the needle having a diameter slightly larger than duct 29.

A valve, generally referred to as 30, includes a stem 31 having a roller 32 on one end thereof and a closure element 33 on the other end. Closure 33, connected to a pivot pin 34 extending within the housing, is of a configuration similar to that of a geometric segment, that is, a substantially cylindrical member having a portion of its arcuate peripheral surface cut by a line or plane. Roller 32 rides along a track 35 as the transfer device is reciprocatably moved horizontally therealong by conventional drive means 38 connected thereto, the device moving between wafer vacuum pick-up and release areas. Track 35 is vertically movable by a cam follower 36 travelling about cam 37 thereby causing a pivotal movement of valve 30 to effectuate either a vacuum pick-up or a gas release of the wafer or to inactivate the needle.

In operation, as seen in FIG. 1, head 10 is shown in its unoperated position during movement along track 35 between the wafer pick-up and release areas. The valve is disposed in a rotated clockwise position such that are 40 of the closure element 33 is located in a complementary arcuate groove portion 4% of air passage 14 thereby blocking the inlet side thereof, that is, that portion of the passage just above duct end 21, to prevent any flow of compressed air therethrough as well as through the duct end 21.

As seen in FIG. 2, head 10 is located at the pick-up area over a wafer tray 39 wherein needle 23 picks up a wafer 11 therefrom as track 35 is vertically moved to wards its down position. The valve is disposed in a midposition such that are 40 of closure element 33 is removed from groove portion 40a and closure line 41 is perpendicular to duct end 21. In this position, a portion of the passage near the duct end 21 is constricted by closure line 41 causing a decrease in pressure at said portion when compressed air flows through air passage 14. In so doing, a venturi effect is produced at duct end portion 21, that is, a reduced or negative pressure is created thereby producing a suction in needle 23 to pick up the wafer.

As seen in FIG. 3, the head is shown located at the release area wherein needle 23 is located over header 12 to release wafer 11 thereon as track 35 is lowered to its down position. In this position, valve 30 is disposed in a rotated counterclockwise position such that are 42 of closure element 33 is located within a complementary groove portion 42a of air passage 14 thereby blocking the exhaust side thereof, that is, that portion of the air passage located just beneath duct end 21. As a result, the compressed air only passes through the connecting duct 20 thereby causing the wafer to be discharged from the needle onto the header. After the wafer is discharged, valve roller 32 moves vertically upwards via cam 37 and follower 36 so that closure are 40 blocks passage 14 and duct end 21 to prevent any passage of air therethrough thereby rendering the device inactive, as seen in FIG. 1. Head 10 then moves vertically upwards and horizontally along track 35 by drive means 38 through another cycle.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope. thereof.

What is claimed is:

1. A device for lifting and releasing semiconductor articles at predetermined areas, which comprises:

a housing adaptable for connection to a source of com pressed at and having a passage extending there-- through;

a duct having one end communicating with the pas,

sage, said duct having a diameter smaller than the.

second positions such that, in said first position, the

closure linear surface is parallel to the passage wall. and perpendicular to said one end of the duct thereby causing a constriction of a portion of the passage to decrease the pressure thereat to create a venturi effect for producing a suction in the needle to pick up the article, and such that, in said second position, the closure bottom surface is disposed beneath the one end of duct to block the passage and permit the compressed air to pass through the needle to release the article therefrom;

a track designed for engagement with a portion of the valve stem;

a cam follower connected to the track; and

acam in movable contact with the cam follower for moving the valve stem to operate the valve.

2.: A device according to claim 1, further including:

I means for reciprocatably moving the device substantially horizontally be'tweenthe predetermined areas;

' and r v r aroll-er-connectedto the end of the valve stemoutside the housing in engagement with the track for travel thereupon during the horizontal movement of the device, so that movement of the track causes move ment of the roller to operate the valve.

' 3 A device according to claim 2, in which:

the closure upper surface is arcuately shaped;

a portion of the passage has a complementary arcuate groove thereinyand the came is capable of moving the valve to a third position where said passage arcuate groove receives a section of the closure upper surface to blocksaid duct other end and that portion of the passage located therebeneathto render the device inactive.

References Cited in the file of this. patent UNITED STATES PATENTS 671,671 Horsleyfl Apr. 9, 1901 702,124 Benton- June 10, 1902 1,491,115 ,Taylor Apr. 22, 1924 1,589,800 Frank June 22, 1926 2,606,610 Collier "a. Aug. 12, 1962 2,874,989 Reynolds Feb. 24, 1959 3,056,317 Huber Oct. 2, 1962 FOREIGN PATENTS 849,882 Great Britain Sept. 28, 1960

Claims (1)

1. A DEVICE FOR LIFTING AND RELEASING SEMICONDUCTOR ARTICLES AT PREDETERMINED AREAS, WHICH COMPRISES: A HOUSING ADAPTABLE FOR CONNECTION TO A SOURCE OF COMPRESSED AIR AND HAVING A PASSAGE EXTENDING THERETHROUGH; A DUCT HAVING ONE END COMMUNICATING WITH THE PASSAGE, SAID DUCT HAVING A DIAMETER SMALLER THAN THE PASSAGE, A NEEDLE CONNECTED TO THE OTHER END OF THE DUCT AND ADAPTABLE FOR CONTACT WITH AN ARTICLES; A VALVE HAVING A CLOSURE END PORTION WITHIN THE HOUSING AND IN THE PATH OF THE PASSAGE, SAID CLOSURE END PORTION HAVING AN UPPER AND LOWER PERIPHERAL SURFACED CONNECTED BY A SUBSTANTIALLY LINEAR SURFACE, SAID VALVE INCLUDING A STEM EXTENDING FROM THE CLOSURE END PORTION AND THROUGH THE HOUSING, SAID VALVE BEING MOVABLE BY MANIPULATION OF THE STEM TO FIRST AND SECOND POSITIONS SUCH THAT, IN SAID FIRST POSITION, THE CLOSURE LINEAR SURFACE IS PARALLEL TO THE PASSAGE WALL AND PERPENDICULAR TO SAID ONE END OF THE DUCT THEREBY CAUSING A CONSTRUCTION OF A PORTION OF THE PASSAGE TO DECREASE THE PRESSURE THEREAT TO CREATE A VENTURI EFFECT FOR PRODUCING A SUCTION IN THE NEEDLE TO PICK, UP THE ARTICLE, AND SUCH THAT, IN SAID SECOND POSITION,

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