Probe and Inverting Apparatus

The present invention relates generally to devices for handling articles such as computer chips and particularly to inverting apparatus and to pick up probes.

During the manufacture of articles such as computer chips, such articles must be tested for operability, efficiency, and other conditions. It is especially desirable to automate such testing to reduce the amount of labor required in performing such tests. Thus, a need exists for devices which mechanically handle such articles to allow automated testing. This need includes devices or probes which are able to pick up and/or place such articles at desired locations and which do not have a tendency to damage such articles including delicate parts thereof such as the connecting leads on a computer chip. This need also includes devices for inverting such articles to allow automated testing on both sides of the article, which devices also not having a tendency to damage such articles including delicate parts thereof such as the connecting leads on a computer chip.

The present invention solves these needs and other problems in the field of chip handling by providing, in the most preferred form, a method for inverting an article where the first surface of an article is attached and then moved in a first direction. The article is then tipped 90.degree. and the second opposing surface is then attached. After release of the first surface, the article is then again tipped 90.degree.. After moving the article in a direction opposite to the first direction, the second surface of the article is released, with the article being inverted from its initial position.

In a preferred form, the article is inverted by an apparatus which selectively positions first and second probes between a first, parallel relation and a second, in line relation, with the probes including reciprocal pins for removable attachment to the article. In a most preferred form, the probes are pivotably mounted to a housing and to a block which is reciprocally mounted relative to the housing, with the probes being simultaneously pivoted as the block is reciprocated between first and second positions.

In a further aspect of the present invention, a probe is provided including a pin reciprocally mounted in a housing for reciprocation in upper and lower chambers. The pin includes a piston which defines a pressure chamber in the lower chamber and includes an internal passage in fluid communication with the upper chamber. Fluid communication is provided to the upper chamber and the pressure chamber for removably attaching an article to the pin and/or for reciprocating the pin within the housing.

It is thus an object of the present invention to provide a novel inverting method.

It is thus an object of the present invention to provide a novel inverting apparatus.

It is thus an object of the present invention to provide a novel probe.

It is further an object of the present invention to provide such a novel probe including a reciprocating pin which only retracts when an article is attached thereto.

It is further an object of the present invention to provide such a novel probe which utilizes fluid pressure and vacuum acting on a piston to reciprocate the pin.

It is further an object of the present invention to provide such a novel probe having a volume reducing chamber from the pin retracting into the chamber.

It is further an object of the present invention to provide such a novel probe providing very soft handling of the article.

It is further an object of the present invention to provide such novel inverting method and apparatus providing very soft handling of the article.

It is further an object of the present invention to provide such novel inverting method and apparatus of a relatively simple design.

It is further an object of the present invention to provide such novel inverting method and apparatus which passes the article between first and second probes movable between parallel and in line positions.

These and further objects and advantages of the present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings.

The illustrative embodiments may best be described by reference to the accompanying drawings where:

FIG. 1 shows an exploded, perspective view of an invertor including probes according to the preferred teachings of the present invention.

FIG. 2 shows an exploded, perspective view of the probe of FIG. 1.

FIGS. 3-5 show front views of the invertor of FIG. 1.

FIG. 6 shows a cross sectional view of the probe of FIG. 1.

FIG. 7 shows an exploded, perspective view of an alternate embodiment of an invertor according to the preferred teachings of the present invention.

All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the Figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood.

Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms "first", "second", "vertical", "horizontal", "central", "upper", "side", "end", and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention.

An apparatus for inverting an article such as a chip on a conveyor or the like according to the preferred teachings of the present invention is shown in the drawings and generally designated 10. Inverter 10 generally includes first and second probes 12 and 14 which are pivotably mounted to a stationary mount 16 and to a reciprocating block 18.

In the most preferred form, mount 16 includes a U-shaped housing 20 including a central plate 22 and first and second upstanding legs 24. Suitable provisions 26 such as mounting apertures are provided for mounting housing 22 in a stationary condition relative to conveyor 28. An L-shaped actuator mounting plate 30 is secured to the upper end of housing 22 such as by screws 32 extending through the horizontal leg 33 of plate 30. A lower end plate 34 is secured to the opposite end of housing 22 such as by screws 36. First and second guide shafts 38 are mounted and extend between horizontal leg 33 of plate 30 and plate 34 parallel to and spaced from each other, from plate 22, and from legs 24. It should be appreciated that guide shafts 38 may be mounted in any suitable manner such as being press fit in and upstanding from plate 34 or from horizontal leg 33 of plate 30, may be slideably captured between horizontal leg 33 of plate 30 and plate 34, or may be similarly mounted.

Block 18 in the most preferred form is generally an inverted T-shape and is reciprocally mounted on guide shafts 38 such as by passages 40 formed in block 18 for slideably receiving guide shafts 38. Block 18 is reciprocated on guide shafts 38 within housing 20 by a rotary actuator 42 mounted to the vertical leg 43 of plate 30 such as by screws 44. In the preferred form, the output shaft 45 of actuator 42 passes through a bore formed in vertical leg 43 of plate 30 and is rotatably secured to an end of a crank am 46. The first end of a connecting wire 47 is rotatably secured to the opposite end of crank arm 46 such as by being secured to a ring 48 rotatably mounted by a bushing 49 located on a screw threadably received adjacent the free end of crank arm 46. Wire 47 extends from crank arm 46 through a bore 51 formed in horizontal leg 33 of plate 30 and has its opposite end secured to block 18. In the preferred form, a channel 52 is formed in block 18 parallel to and intermediate passages 40, with wire 47 being attached the head of block 18 in the closed end of channel 52.

In the most preferred form, rotary actuator 42 rotates output shaft 45 180.degree. and specifically between a first position wherein crank arm 46 is generally vertical with ring 48 located below output shaft 45 and a second position wherein crank arm 46 is generally vertical with ring 48 located above output shaft 45. It can then be appreciated that due to the connection of wire 47 between the free end of crank arm 46 and block 18, as output shaft 45 is rotated, block 18 reciprocates on guide shafts 38 between a first position adjacent to end plate 34 and a second position adjacent to plate 30. It should then be appreciated that suitable bumpers may be provided on plate 30 and/or 34 to act as shock absorbers to reduce the force with which block 18 may engage plate 30 and/or 34.

Mounting blocks 54 are pivotally mounted on the opposite sides of block 18 such as by pivot pins 56 press fit in blocks 54 and rotatably received in bearings 58 secured in block 18, with a spacer 60 intermediate block 18 and block 54. Pivot links 62 are pivotally mounted on the opposite sides of housing 20 such as by pivot pins 64 received in bores 66 formed in legs 24 of housing 20 and in bearings 67 secured in pivot links 62. Pivot links 62 are pivotally mounted to mounting blocks 54 by dowel pins 68 press fit in block 54 and rotatably received in a bearing secured in link 62. Probes 12 and 14 are mounted on mounting blocks 54 on opposite sides of block 18 such as by screws 70.

It can then be appreciated that due to the pivotal mounting of probes 12 and 14 about stationary pivot pins 64 and about movable pivot pins 56, the positioning of probes 12 and 14 relative to each other changes with the reciprocation of block 18 within housing 20 by actuator 42. Specifically, and in the preferred form, with block 18 in its first position adjacent end plate 34, probes 12 and 14 are in a vertical, parallel relation. However, with the rotation of actuator 42 moving block 18 to its second position adjacent plate 30, probes 12 and 14 are in a horizontal, in line relation.

Inverter 10 according to the preferred teachings of the present invention also includes probes 12 and 14 of a unique and advantageous construction. Specifically, probes 12 and 14 generally include a housing 72 divided to define an upper air chamber 74 and a lower chamber 76 by an insert 78. Probes 12 and 14 further include a suction pin 80 slideably mounted in insert 78 and reciprocally mounted in chambers 74 and 76. In the most preferred form, suction pin 80 includes an upper portion 82 having a square or other non-circular cross section, with insert 78 having a passage 84 of a complementary configuration to prevent rotation of suction pin 80 within housing 72 and insert 78. A piston 86 is secured to suction pin 80 for reciprocation within chamber 76 for defining a lower air chamber 88 between insert 78 and piston 86. Suitable provisions 90 and 92 such as ports are provided to allow fluid communication to chambers 74 and 88. Pin 80 includes an internal passage 94 in communication with air chamber 74.

In the most preferred form, suction pin 80 includes a sleeve 110 which removably receives and is in fluid communication with a probe tip 112 having a suitable suction cup. 114, with probe tips 112 and cups 114 being of various types and configurations. Sleeve 110 includes upper portion 82 and a lower portion 116, with piston 86 being slideably received on and sealing with portion 116. Suitable provisions such as a snap ring 118 received in a groove formed in sleeve 110 may be provided for holding piston 86 in place on sleeve 110.

In the most preferred form, housing 72 is formed by a chamber portion 120 including a through passage 122. A first enlarged bore 124 extends from the first end of portion 120 concentric with passage 122 and terminating at a location spaced from the second end of portion 120. Piston 86 is reciprocally received in a cylinder tube 126 which in turn is slideably received in bore 124. Tube 126 is held in bore 124 by an O-ring 128 received in a groove formed in chamber portion 120, with O-ring 128 also sealing tube 126 with bore 124 and also acting as a stop to prevent piston 86 from sliding out the free end of cylinder tube 126. It can then be appreciated that tube 126 can be formed of low friction material such as pyrex glass and piston 86 can be similarly formed of low friction material such as carbon which facilitates reciprocation of piston 86 in tube 126 and which allows reduced tolerance requirements for bore 124 such that housing 72 may be easily formed of aluminum.

Chamber portion 120 includes a second enlarged bore 130 extending from the second end of portion 120 concentric with passage 122 and terminating at a location spaced from bore 124. Chamber portion 120 further includes a third enlarged bore 132 extending from the second end of portion 120 concentric with passage 122 and bore 130 and terminates at a location spaced from bore 124 and the termination of bore 130, with bore 132 being larger than bore 130. Insert 78 is of a size and shape complementary to, for slideable receipt in, and for sealing with bore 130.

Housing 72 is further formed by a top portion 134 according to the preferred teachings of the present invention having an outside configuration generally the same as chamber portion 120. The lower end of top portion 134 includes a removed portion to define a projecting lip 136 having a radial size complementary to but slightly smaller than bore 132 and a length generally equal to the depth of bore 132. Lip 136 includes a diagonal key slot 138 of a depth less than the height that lip 136 projects from top portion 134. Insert 78 includes upstanding tabs 140 which extend into bore 132 and are received within key slot 138 to prevent relative rotation of insert 78 with respect to top portion 134 and thus of housing 72, with the height of tabs 140 being less than the depth of key slot 138 to provide a fluid path therebetween. Suitable sealing means such as an O-ring 142 is provided between bore 132 and lip 136. Top portion 134 may be secured to chamber portion 120 by suitable means such as screws 144 extending through chamber portion 120 and threadably received in lip 136 of top portion 134. A bore 146 is provided in top portion 134 generally contiguous and in line with passage 122 for reciprocal receipt of upper portion 82 of sleeve 110.

In the most preferred form, mounting block 54 includes parallel mounting ears 148 which are slideably received in slots 150 formed in chamber portion 120 for maintaining the relative position thereof when probes 12 and 14 are secured by screws 70 extending through mounting block 54 and threadably received in chamber portion 120. It can be appreciated that mounting block 54 includes suitable passages for fluid communication with ports 90 and 92 of housing 72 of probes 12 and 14.

It can then be appreciated that pin 80 can be reciprocated in housing 72 by applying fluid pressure to chamber 88 to extend pin 80 from housing 72 or by withdrawing fluid pressure under a vacuum from chamber 88 to retract pin 80 into housing 72. It can further be appreciated that fluid pressure can be applied to chamber 74 such that fluid pressure will pass through passage 94 of pin 80 and that fluid pressure can be withdrawn under a vacuum from chamber 74 such that passage 94 of pin 80 is likewise under vacuum. It should then be appreciated that if passage 94 is blocked such as by a chip 98 attached to the lower end of pin 80, pin 80 will be biased to retract into housing 72 to reduce the overall volume of chamber 74 and passage 94 under a vacuum force.

Now that the basic construction of invertor 10 and probes 12 and 14 has been explained, the operation, subtle features, and advantages thereof can be set forth and appreciated. For purposes of explanation, it will be assumed that block 18 is in its first position with probes 12 and 14 in their vertical, parallel relation and that pins 80 are retracted within housing 72 of probes 12 and 14. Fluid pressure may be introduced into chamber 88 through port 92 of probe 12 to extend pin 80 of probe 12. Prior to or when the lower end of pin 80 engages the upper surface 96 of a chip 98 on a conveyor 28 or the like, chamber 74 of probe 12 may be subjected to a vacuum to attach surface 96 of chip 98 to pin 80. After attachment, fluid pressure to chamber 88 of probe 12 may be terminated and chamber 88 may be vented with the venting of chamber 88, pin 80 will retract in a first direction generally perpendicular to surface 96 into housing 72 of probe 12 under the vacuum force of chamber 74. After pin 80 of probe 12 is retracted, block 18 may be reciprocated to its second position by actuator 42 such that probes 12 and 14 are in their horizontal, in line relation and chip 98 is tipped 90.degree. with surface 96 being parallel to the first, retraction direction of probe 12. At that time, pin 80 of probe 12 may be extended in a direction which is perpendicular to the first, retraction direction of probe 12 by applying fluid pressure to chamber 88. Pin 80 of probe 14 may also be extended in a direction which is perpendicular to the first, retraction direction of probe 12 by applying fluid pressure to chamber 88 so that pin 80 of probe 14 abuts the lower surface 100 of chip 98 which is opposing surface 96. Prior to or when pin 80 of probe 14 engages surface 100, chamber 74 of probe 14 may be subjected to a vacuum to attach surface 100 of chip 98 to pin 80 of probe 14. After attachment to pin 80 of probe 14, the vacuum to chamber 74 of probe 12 may be discontinued and chamber 74 of probe 12 may be vented to release the attachment of pin 80 of probe 12 to chip 98. After attachment to probe 14, fluid pressure to chamber 88 of probe 14 may be terminated and chamber 88 of probe 14 may be vented with the venting of chamber 88 of probe 14, pin 80 of probe 14 will retract into housing 72 of probe 14 under the vacuum force of chamber 74 of probe 14. After release, a vacuum may be introduced into chamber 88 of probe 12 to retract pin 80 within housing 72 of probe 12. After the retraction of pins 80 of probes 12 and 14, block 18 may be reciprocated to its first position by actuator 42 such that probes 12 and 14 are in their vertical, parallel relation and chip 98 is tipped 90.degree. with surface 100 being perpendicular to the first, retraction direction of probe 12. At that time, pin 80 or probe 14 may be extended in a direction opposite to the first, retraction direction of probe 12 by applying fluid pressure to chamber 88 until surface 96 of chip 98 engages conveyor 28 and surface 100 now being on top. At that time, the vacuum to chamber 74 of probe 14 may be discontinued to release chip 98, with chamber 74 of probe 14 either being vented or subjected to a puff of fluid pressure to push chip 98 away from the lower end of pin 80. After release, pin 80 of probe 14 may be retracted by placing chamber 88 of probe 14 under a vacuum. At that time, chip 98 may be conveyed on conveyor 28 but in an inverted condition.

It can then be appreciated that invertor 10 is able to invert chip 98 utilizing a relatively simple mechanism which does not attach to or utilize the chip leads in the inverting method. Thus, invertor 10 is not as prone to chip damage or breakage as in prior inverting apparatus.

The configuration Of block 18 is believed to be advantageous according to the preferred teachings of the present invention. Specifically, channel 52 allows the nesting of wire 47 such that the overall height of invertor 10 can be reduced while the length of passages 40 can be maximized to allow free reciprocation of block 18 on guide shafts 38 without binding.

Further, the construction of probes 12 and 14 is believed to be advantageous according to the preferred teachings of the present invention. Specifically, chamber 88 which may be subjected to pressure or a vacuum to reciprocate pins 80 allows the soft handling of chips 98 in comparison to prior probes which utilized springs to bias the pin in one direction or which utilized physical movement of the probe to push the pin. Further, the use of pin 80 reciprocating in chamber 74 to cause a volume reduction when under vacuum and the elimination of spring biasing forces of prior probes, allows the vacuum applied to pin 80 to retract pin 80 within probes 12 and 14. This is particularly advantageous since if chip 98 does not abut the lower end of pin 80, passage 94 is open to the atmosphere. Pin 80 retracts only when chip 98 abuts the-lower end of pin 80 to close pin so and chamber 74 such that the vacuum will reduce the overall volume of chamber 74 and passage 94 to retract pin so within chamber 74. Thus, mechanical control can be easily accomplished by detecting the vacuum pressure applied to chamber 74 and/or by detecting the retraction of pin 80 in signaling attachment to chip 98 by probes 12 and 14.

Further, the method of reciprocation of block 18 and probes 12 and 14 mounted thereon is believed to be particularly advantageous according to the preferred teachings of the present invention. Specifically, block 18 is reciprocated at a sinusoidal rate of velocity due to the pivotal mounting of the end of wire 47 to the free end of crank arm 46 which is rotated by shaft 45 of actuator 42. This sinusoidal drive effect may also be possibly enhanced by electrically controlling actuator 42 to rotate shaft 45 at a sinusoidal rate of velocity. This sinusoidal drive effect allows the velocity of block 18 to approach zero when approaching plates 30 and 34 to prevent the abrupt stopping of block 18 which may shake chips 98 attached to probes 12 and 14 to either detach therefrom or to slip in position relative thereto.

Now that the basic teachings of the present invention have been explained, many extensions and variations will be obvious to one having ordinary skill in the art. For example, invertor 10 can include provisions for varying the overall vertical position of probes 12 and 14. In a preferred form of a further embodiment of the present invention as shown in FIG. 7, mount 16 includes central plate 22 including first and second spaced, vertical grooves 152 and 154. The vertical leg 143 of actuator mounting plate 30 is secured to the upper end of central plate 22 such as by screws 32. The track portions of reciprocable slides 156 and 158 are mounted within grooves 152 and 154 such as by screws 160. Slides 156 and 158 in the most preferred form are of the ball slide type such as sold by Del.Tron Precision, Inc. of Brookfield, Conn.

Mount 16 further includes a U-shaped link mounting plate 162. Plate 162 generally includes first and second legs 164 which extend in a spaced, parallel manner from the opposite ends of a central portion 166. Bores 66 are formed in and adjacent to the free ends of legs 164 of mount 16. A block 168 is secured to the slide portion of slide 158 such as by screws 170 for reciprocal movement relative to central plate 22. Plate 162 is secured to block 168 and in the preferred form in a manner allowing side-to-side adjustment while providing close tolerances for vertical positioning. Specifically, spaced first and second pins 172 are press fit into block 168 and extend into elongated slots 174 in central portion 166 of plate 162. Slots 174 can be machined or otherwise formed with close tolerances relative to pins 172 to prevent vertical movement but allowing horizontal or side-to-side movement. To hold plate 162 in position relative to block 168, a screw 176 extends through an elongated slot 177 formed in central portion 166 of plate 162 and is threadably received in block 168. Block 168 and plate 162 secured thereto are reciprocated on slide 158 by a linear actuator 178 mounted to the horizontal leg 133 of plate 30 such as by screws 180. In the preferred form, the output shaft 182 of actuator 178 passes through a bore 184 formed in horizontal leg 133 and is threadably received in block 168.

In the preferred form, actuator 178 moves shaft 182 linearly in a vertical direction. It can then be appreciated that with vertical movement of plate 162 and block 168 secured to shaft 182, bores 66 formed in plate 162 and pins 64 about which links 62 pivot correspondingly move vertically. It can be appreciated that plates 22 and 162 and block 168 form housing 20 which allows pivot pins 64 defining the pivot axes for links 62 and probes 12 and 14 to be vertically movable in a controlled manner. Linear actuator 178 allows the overall vertical positioning of probes 12 and 14 to be varied without abrupt movement or stopping which may shake chips 98 attached to probes 12 and 14 to either detach therefrom or to slip in position relative thereto.

Block 18 in the most preferred form is secured to the slide portion of slide 156 such as by screws 186 for reciprocal movement relative to central plate 22. Block 18 is reciprocated on slide 156 by a linear actuator 188 also mounted to horizontal leg 133 of plate 30 such as by screws 190. In the preferred form, the output shaft 192 of actuator 188 passes through a bore 194 formed in horizontal leg 133 and is threadably received in block 18. In the preferred form, actuator 188 moves shaft 192 and block 18 secured thereto linearly in a vertical direction. Linear actuator 188 pivots probes 12 and 14 between their vertical, parallel relation and their horizontal, in line relation without abrupt movement or stopping which may shake chips 98 attached to probes 12 and 14 to either detach therefrom or to slip in position relative thereto. In the form shown in FIG. 7, pivot pins 56 are rotatable relative to block 18 by bearings 58, with the bearing mount 196 spacing block 18 from block 54.

It can be appreciated that due to the pivotal mounting of probes 12 and 14 about pivot pins 56 and 64, the positioning of probes 12 and 14 relative to each other changes with the reciprocation of block 18 relative to plate 162 of mount 16 by actuator 188 in the manner as set forth for FIGS. 1 and 3-5. However, with invertor 10 of the embodiment of FIG. 7, the vertical position of pivot pins 64 and thus of probes 12 and 14 can be varied by actuation of actuator 178. It can further be appreciated that the degree of movement of chip 98 is no longer dependent upon the stroke of suction pins 80 of probes 12 and 14. Thus, invertor 10 of FIG. 7 allows chip 98 to be removed from and placed upon conveyors 28 of unequal heights and/or allows invertor 10 to tip larger chips 98 of a size which would abut conveyor 28 if suction pins 80 were simply retracted into probes 12 and 14 and then probes 12 and 14 tilted. It can also be appreciated that actuator 188 may be simultaneously actuated with actuator 178 to maintain the relative positions between pivot pins 56 and 64 and thus the relative relations of probes 12 and 14 as plate 162 is moved by actuator 178.

Further, although probes 12 and 14 of the type disclosed in the preferred form are believed to be particularly advantageous and produce synergistic results when utilized with invertor 10 according to the teachings of the present invention, invertor 10 may utilize other types and forms of probes according to the teachings of the present invention. For example, fluid communication can be applied directly to sleeve 110 extending through a passage formed in top portion 134 and chamber 74 can be omitted from probes 12 and 14.

Likewise, it can be appreciated that probes 12 and 14 according to the teachings of the present invention may be utilized in other applications than in invertor 10 of the preferred forms where automated handling of chips 98 or other articles is desired.