WO1992002806A1

WO1992002806A1 - Lead inspection straightening apparatus and method

Info

Publication number: WO1992002806A1
Application number: PCT/US1991/005156
Authority: WO
Inventors: Frank V. Linker, Sr.; Edward T. Claffey; Frank V. Linker, Jr.
Original assignee: American Tech Manufacturing, Corp.
Priority date: 1990-08-09
Filing date: 1991-07-22
Publication date: 1992-02-20

Abstract

Apparatus for scanning the lead to lead integrity of electronic devices (D) having an axial length and leads (L) extending from the side. A track means (19) moves devices (D) along a path to a scanning station (27). Pins (16) stop each of said devices (D) at locations on the path where a clamp rail (21) assists in positioning the device (D). The scanning unit is movably positioned at the station for movement along the length of the device (D) to generate a signal upon intersection of leads (L). Signals from the scanner are compared with predetermined signals to determine the existence and spacing of each lead (L) with respect to a predetermined pattern. Lead straightening heads (28) comprised of fingers engages between the leads (L) on opposite sides of the device (D). The track (19) includes a first station (27) for lead to lead scanning, a second station (28) for coplanarity scanning, a third station (22) for lead to lead straightening, and a fourth station (23) for coplanarity adjustment.

Description

LEAD INSPECTION STRAIGHTENING APPARATUS AND METHOD

TECHNICAL FIELD

The present invention relates generally to improvements in apparatus and method for straightening electronic components of the type commonly referred to as DIP devices. These devices are used as semiconductors or resistors in integrated circuit boards or the like. More specifically, the apparatus and method of the present invention are designed for scanning the lead integrity of DIP devices along the axial length, to determine the existence and spacing of each lead with respect to a predetermined pattern. In addition, the present invention relates to apparatus for fully inspecting and aligning leads on DIP devices in a single apparatus.

BACKGROUND ART

DIP devices and particularly the new "gull-winged" DIP devices form an important part of the electronics industry. These DIP devices are placed on a printed circuit board which has been silk screened and treated to define precise locations for the pads of the DIP device leads. Precise location of the DIP device is needed for successful manufacturing.

DIP devices are required to meet certain standards of uniformity, both in the distance between individual pins or leads and in the coplanarity of the leads which extend down from the body for attachment to the printed circuit board. For example, manufacturing standards for a particular device may call for the pads of the DIP device all to be within a range of ten thousandths to twenty thousandths of an inch. Various manufacturers and various products may have different body stand-off ranges, such as ten to twenty thousandths, or seven to twelve thousandths and the like.

Additionally, all of the leads must be within four thousandths of an inch in coplanarity of each other in order to ensure proper mounting on the PC board. The four thousandths coplanarity range is becoming an industry standard. Coplanarity inspection and adjustment is a significant need in the electronic industry.

As was mentioned above, the specifications for the distances between pins or leads is also of major concern. It has become desirable to ensure that the distance between leads is within a certain range, for example a distance of ten thousandths of an inch. Each of the many leads on the DIP device will then contact the appropriate pad on the printed circuit board. Scanning is extremely important to verify that none of the pins or leads are missing. Those DIP devices which have a missing, or widely skewed lead, need to be taken out of the automatic assembly process.

The manufacturing processes by which DIP devices are made are themselves highly automated and efficient. In some instances, less than two percent of the devices made will be out of tolerance by an amount sufficient to need straightening, either in the pin to pin direction or with respect to coplanarity of all of the leads. In other manufacturing processes, depending upon the quality and the complexity, the number of DIP devices from a given production run which needs straightening will range from as low as one percent to as high as ten percent. In most cases, the DIP devices which do not meet the initial specifications are still within a range which would permit them to be straightened or realigned. Actual rejection due to a missing lead or a badly skewed lead is extremely low. Nevertheless, it is becoming an industry standard to inspect every DIP device as part of the assembly process.

Apparatus and system for straightening DIP devices are not new per se. There are several patents owned by the common assignee of the present application showing apparatus and system for straightening DIP devices which have a generally rectangular body portion and a series of a fingers or leads projecting from opposite side edges of the body portion which are generally elongated straight fingers.

Inventor Title Patent No. Issued

Linker ELECTRONIC COMPONENT 4,481,984 11/13/84 LEAD STRAIGHTENING

DEVICE & METHOD Linker HIGH SPEED ELECTRICAL 4,787,426 11/29/88 COMPONENT LEAD FORMING APPARATUS & METHOD

In these apparatus, the DIPs are usually fed by gravity along an elongated trackway through various stations including a lead straightening station where the fingers of combs moving transversely to the trackway engage between the fingers and in this manner align the leads in relation to one another. These prior apparatus have been found to be effective for the purposes intended. However, the "gull-winged" DIP device because of the complex shape of the leads which are generally Z-shaped configuration present different problems in the straightening or aligning process. Furthermore, in the "gull-winged" DIP devices, it is essential that the pads of the leads lie in a common plane for proper assembly to the printed circuit board. In other words, there needs to be coplanarity of the pads before a DIP device is suitable for assembly.

While the above described apparatus is efficient and effective, it is a waste of time to straighten or align the leads of a device which has one or more leads missing or when the leads are too far from acceptable standards. Such devices should be discarded. It is also unnecessary to subject already straightened DIP devices to additional straightening. Accordingly, it is a principle object of this invention to provide an inspection apparatus for use with the above described straightening apparatus which will reject defective DIP devices and pass acceptable DIP devices without requiring additional operation of the straightening or aligning apparatus.

There are also various methods which are proposed for determining the relative alignment of the individual pins or leads of DIP devices. As can be determined from the very name of DIP devices. Dual In-Line Packages, the body portion of a DIP device has a plurality of leads extending from two sides generally perpendicular to the longitudinal axis of the device. Various devices have been proposed which scan the pin to pin relationship of the leads on DIP devices. Devices which pass the scanning test can then continue on in the manufacturing process while those which fail the test must be removed, either at the time of inspection or after the entire batch of devices has been scanned.

As one can imagine, there are alternative processes in the electronics industry. One such alternative is to straighten and position all of the leads on all of the devices prior to use. This is time consuming, expensive and potentially hazardous, particularly for fragile leads. The other alternative is to scan each individual lead and transfer those leads which need adjustment to the appropriate adjustment station. As a sufficient quantity of out of specification DIP devices accumulate, they can then be placed in a straightening device of the type described above. This may be suitable for small operations or operations which do not have an extremely high production rate. As more and more assembly facilities are being automated and the efficiencies of the automated plants are being upgraded, separation of the devices in this manner becomes non-productive or uneconomic.

The alternative to independently testing all of the leads and separating those which need straightening is the aforementioned process of straightening and aligning all of the leads. Even with virtually one hundred percent acceptance after straightening, these systems operate too slowly to be competitive in high volume assembly environments.

Accordingly, another object of the present invention is to provide a device which is capable of inspecting DIP device leads both from lead to lead distance, and for coplanarity, followed by selectively straightening those DIP devices which need adjustment to meet specification, even though that may be two percent or less of the total quantity processed. At the same time, it is an object of this invention to provide a machine which is capable of inspecting DIP devices for location and coplanarity alignment without subjecting those within specification to additional stress.

Yet another object of this invention is to provide a device which optimizes the inspection and adjustment of leads on DIP devices at a maximum rate with minimum stress on the device:

DISCLOSURE OF INVENTION

It has now been discovered that the above and other objects of the present invention may be accomplished in the following manner. Specifically, a lead scanning apparatus has been discovered which permits scanning lead to lead integrity of electronic devices such as DIP devices. It has also been discovered that apparatus can be provided for inspecting and straightening DIP device lead integrity and coplanarity in one assembly or system.

The lead scanning station of the present invention includes a track means for moving individual DIP devices axially along a path. A scanning station means is provided on the path, including stop means for stopping each of the devices at a predetermined location on the path. Holding means are included for positioning the device in a scanning orientation.

Also included in the present invention is a scanning means which is movably positioned at the scanning station to move axially along the length of the device to provide a signal upon intersection of leads extending from the device. Finally, comparator means are provided for comparing actual signals from the scanning means with a predetermined set of signals in order to determine the existence and spacing of each j.ead with respect to a predetermined pattern. A signal based upon the comparison for each device is generated, typically indicating whether the device passes predetermined specifications, or is within a range where the device may be fixed, or is in a condition where it must be rejected. Rejected devices, _*rould, for example, have one or more leads missing.

The invention also contemplates the apparatus for both inspecting and straightening lead integrity and coplanarity for devices such as DIP devices. This apparatus includes a track for defining a path of travel for DIP devices along their axial length. The path moves from an inlet which is adapted to release individual leads upon command to a series of stations. These stations are arranged sequentially on the path so that the first station provides lead to lead scanning, such as described above. The second station tests the DIP device for lead coplanarity. The third station operates to straighten the lead to lead relationship, while the fourth station adjust coplanarity of the device, if necessary. Finally, the path reaches an outlet station.

On the tracking means and aligned therewith is a clamping rail which is operatively designed to clamp the devices at any location on the track. Stop means are provided to stop the device along the track at each of the stations. Upon arrival of a device at a stopping means, the clamping rail means is activated.

The apparatus of this invention is controlled by controller means which sequentially activate the first and second stations, whereby first and second signals are generated. These signals indicate whether or not the particular device passes specifications, or falls within the predetermined guideline for straightening or adjusting coplanarity, or are so far out of line or otherwise unacceptable as to be rejected. The controller means activates both the third and fourth stations upon generation of a fixed signal from either or both of the first and second stations. In this manner, a device which is slightly off specification, needing its leads to be straightened or adjusted in coplanarity, will stop at the third and fourth stations. Stations there and four would then be activated to perform the straightening and adjusting functions. If both the first and second stations generate a pass signal, indicating that the device is within specification, this acceptable DIP device will travel the remaining path of the track means without activation of either the third or fourth stations. Similarly, if the signal generated by the first and second stations indicate that the DIP device should be rejected, it too will pass the third and fourth stations without those stations being activated.

All of the DIP devices inspected by the apparatus of this invention are received at the outlet station. The outlet station is adapted to separate DIP devices based upon the signal it receives from the controller means. Specifically, if a DIP device generates a pass signal or a fix signal it will arrive at the outlet station in an acceptable or usable condition. These signals will instruct the outlet station to separate them from those DIP devices which have generated a reject signal. Rejected devices will be separated and removed from the manufacturing process.

It is contemplated that various coplanarity inspection and adjusting stations will be used in combination with the present invention, along with various scanning and straightening means for adjusting the lead to lead integrity and spacing for electronic packages such as DIP devices.

The DIPs entering a straightening station downstream of the escapement system are aligned so that straightening jaws comprised of a plurality of blades having straightening fingers will engage in the spaces between the leads. At the straightening station, the blades engage between the leads on both sides while the DIP device is in a "floating" condition on the trackway. In this position, the DIP is clamped to the trackway and thereafter the jaws are oscillated to move each of the pins back and forth relative to a vertical plane in a predetermined cycle to effect the desired straightening action. It has been found that the Z-shaped gull winged leads tend to be deformed or bend at the juncture of the lead to the body portion rather than being deformed along their length. Thus, the novel straightening action described is effective to properly align the leads relative to a vertical plane.

After the jaws are cycled, the straightened DIP is released and moves to a coplanarity station downstream of the straightening station. Here the DIP is retained and secured in a fixed position and the pads of the leads on both sides are located in the bite or cavity of a pair of coplanarity jaws. With the DIP device clamped in place, the jaws are cycled in an up and down plane relative to the trackway to pivot the leads about the shoulder at the juncture of the lead and body portion in a direction generally transverse to that described above in connection with the lead straightening cycle. At the straightening and coplanarity stations, the action described effectively removes or eliminates the elastic memory of the material so that the leads once properly oriented will remain in that position in the pattern and spacing desired for proper assembly to a PCB.

BRIEF DESCRIPTION OF DRAWINGS

These and other objects of the present invention and the various features and details of the operation and construction thereof are hereinafter more fully set forth with reference to the accompanying drawings, where:

Fig. 1 is an isometric view, greatly enlarged, of a typical gull-wing DIP device.

Fig. 2 is a side elevational view of a preferred apparatus of the present invention, in which lead inspection and straightening is accomplished.

Fig. 3 is an auxiliary plan view taken along the line 3-3 of Fig. 2, further illustrating the details of the preferred embodiment.

Fig. 4A is an enlarged plan view of a seven lead gull-wing DIP device, such as shown in Fig. 1, illustrating such a device which lacks lead integrity.

Fig. 4B is an enlarged side elevational view of a seven lead gull-wing DIP device, such as shown in Fig. 1, showing improper spacing of some of the leads.

Fig. 4C is an enlarged end elevational view of a seven lead DIP device illustrating leads which are not all within an acceptable range of coplanarity.

Fig. 5 is an flow diagram illustrating the sequential operations performed by the apparatus of the present invention on individual DIP devices.

Fig. 6 is an enlarged, fragmentary, sectional elevational view taken along line 6-6 of Fig. 3, illustrating details of the track. Fig. 7 is an enlarged, fragmentary, transverse sectional elevational view taken along the line 7-7 of Fig. 2, showing certain details of the lead to lead scanning device of this invention.

Fig. 8 is a bottom plan view taken along the line 8-8 of Fig. 7.

Fig. 9 is a sectional, elevational view taken along the lines 9-9 of Fig. 7.

Fig. 10 is greatly enlarged, fragmentary view of the detail contained within the dot and dash rectangle shown in Fig. 7 and designated Fig. 10.

Fig. 11 is an semi schematic, fragmentary plan view of the lower trackway with a seven lead gull-wing DIP device held by a stop pin, shown in dot and dash line.

Fig. 12 is an enlarged, transverse, fragmentary sectional elevational view taken along the line 12-12 of Fig. 2.

Fig. 13 is a sectional, elevational view taken along the line 13-13 of Fig. 12.

Fig. 14 is an enlarged, fragmentary plan view taken along the line 14-14 of Fig. 12.

Fig. 15 is a fragmentary, elevational view taken along line 15-15 of Fig. 14.

Fig. 16 is a perspective view of a typical gull winged DIP device;

Fig. 17A is a side elevational view of a gull winged DIP device shown in Fig. 16 but showing some leads bent with respect to a normal vertical reference plane V'-V' ;

Fig. 17B is a front elevational view of the gull winged DIP device shown in Fig. 16 showing some of the leads bent above and below a horizontal reference plane;

Fig. 18 is a side elevational view of the pin straightening and coplanarity adjusting apparatus in accordance with the present invention for correcting the misalignment of the DIP device leads in both the vertical and horizontal planes;

Fig. 19 is an auxiliary plan view of the pin straightening and coplanarity adjusting apparatus of the present invention taken on lines 19-19 of Fig. 18 showing additional details of the apparatus;

Fig. 20 is an enlarged fragmentary sectional elevational view taken on lines 20-20 of Fig. 19 showing details of the DIP support rail and its cooperating guide and clamping rail mechanism extending from the DIP input station to a DIP discharge station;

Fig. 21 is a schematic enlarged fragmentary side elevational view of the escapement zone, inset in the upper guide and clamping rail assembly, adjacent the input end of the trackway illustrating the indexing and timed release of DIP devices and schematically showing three escapement cylinders and the use of each particular one with respect to the size of the DIP device to be run, ranging in size from eight (8) to twenty-eight (28) pins

Fig. 22 is a fragmentary sectional elevational view taken transversely through the apparatus along line

22-22 of Fig. 18 showing the emergency-job interrupt DIP hold down device adjacent the input station for holding the DIPS on the rail at the input station;

Fig. 23 is an enlarged fragmentary sectional elevational view taken along line 23-23 of Fig. 18 showing the pin straightening station;

Fig. 24 is a fragmentary sectional view of the pin straightening station showing the straightening heads in an operative mode or position;

Figs. 25 and 26 are greatly enlarged fragmentary sectional views of the details contained within the circular dash lines in Figs. 23 and 24 respectively;

Fig. 27 is a sectional side elevational view taken along line 27-27 of Fig. 23 showing additional details of the pin straightening mechanism and a portion of the means for oscillating the pin straightening heads;

Fig. 28 is a fragmentary perspective view of the yoke assembly, utilized in imparting an oscillatory motion to the straightening heads;

Fig. 29 is a fragmentary sectional plan view taken on line 29-29 of Fig. 23 showing the position of the straightening heads relative to a DIP device at the pin straightening station;

Fig. 30 is a fragmentary elevational view of the straightening heads shown in Fig. 29;

Fig. 31 is a perspective view of one of the DIP lead straightening blades that arranged in series adjacent one another comprise the combs of the straightening heads as shown in Figs. 29 and 30.

Fig. 32 is a schematic bottom plan view taken on line 32-32 of Fig. 18 showing additional components and details of the oscillating mechanism;

Fig. 33 is an enlarged transverse sectional view taken on line 33-33 of Fig. 18 showing some of the details of the coplanarity adjusting station;

Fig. 34 is an enlarged fragmentary sectional view of the details contained within the dot and dash circle of Fig. 33 showing the coplanarity heads in a neutral or rest position, and the clamping head exerting a downward force clamping the DIP to the tracking;

Fig. 35 is a fragmentary sectional side elevational view taken along lines 35-35 of Fig. 33 showing additional details of the coplanarity adjusting station;

Fig. 36 is a fragmentary sectional rear elevational view taken along lines 36-36 of Fig. 35;

Fig. 37 is an enlarged fragmentary elevational view taken on the lines 37-37 of Fig. 19 showing details of the adjustable support and actuating means for the clamping and guide rail assembly; and

Fig. 38 is a sectional plan view taken on the lines 38-38 of Fig. 37 showing additional details of the clamping and guide rail assembly. MODES FOR CARRYING OUT THE INVENTION

Fig. 1 is an isometric view of a greatly enlarged typical DIP device. The device D includes a body B and a plurality of leads L. The particular design shown in

Fig. 1 is known as a gull-wing DIP device, so named because of the shape of the leads extending therefrom.

These devices are provided from the manufacture to the user in elongated plastic tubes. The leads of the DIP devices are extremely fragile and easily bent or broken. When"the DIP devices are fed into the automated machinery for placement on PC boards, misaligned and broken leads will fail to make proper circuit contact. For that reason, automated machinery is provided during the production of electronic equipment which examines each lead and verifies that the particular DIP device has straight, correctly spaced, coplanar leads.

In accordance with the invention, DIP devices such as shown in Fig. 1 are inspected and straightened using the apparatus of the present invention. Included within the apparatus of the present invention is a lead scanning station, which, for the first time, permits high speed inspection of one hundred percent of the DIP devices without requiring physical operation on more than those leads which require straightening or coplanarity adjustment. This device, shown in Fig. 2 in a side elevational view, includes a housing or frame 10 which is mounted on pedestal 11 at a fixed 60° angle with respect to the base 12. DIP devices are supplied in tube 13 which can be automatically or manually inserted into a tube receiver 14. Similarly, DIP devices which have been processed by the apparatus of the present invention may be collected by one or more tubes such as tube 16, located at the bottom of the apparatus. The device includes an upper section 17 which houses a first station for lead to lead scanning and a second station for coplanarity scanning. A lower section 18 includes a third station for lead to lead straightening and a fourth station for coplanarity adjustment.

The frame 10 is mounted on pedestal 11 at an angle so that DIP devices will pass through the various stations by gravity feed. Track 19, shown in Fig. 3, includes clamping rail assembly 21 which is aligned to be moved toward track 19 to cooperatively clamp various DIP devices at any location on the track 19.

Output station 24 places each DIP device in its appropriate exit tube 16a, 16b, or 16c. Typically, 16c will be used for rejected tubes, while tubes 16a and 16b are for acceptable DIP devices.

One embodiment of the apparatus of the present invention is designed particularly for straightening the pins P' of so-called gull v^nged DIP devices of the type illustrated in Fig. 16. These DIPS generally comprise an elongated generally rectangular body portion B' made of a molded material such as a plastic and having embedded therein along opposing side edges a plurality of pins or leads P' of generally Z shaped configuration. The lower portions of the Z shaped pins are commonly referred to as the pads Pp' and for proper installation need to be precisely aligned in a common horizontal reference plane H-H' . It is also important that the leads or pins P be aligned relative to a vertical plane V-V . These alignments are extremely important and critical to ensure proper installation to a PC board.

It has been found that the pins or leads P' are extremely delicate and that they tend to misalign during handling and shipment, particularly the leading and trailing pins P' at opposite ends of the body portion B' . The apparatus and method of the present invention are designed for straightening the pins P' so that they are aligned relative to the vertical plane V-V and also to produce coplanarity or alignment of all the pads Pp' in the horizontal plane H'-H' . Even though the method and apparatus of the present invention are particularly suited for these operations on so-called gull winged DIP devices, it is of course to be understood that the apparatus and method may be employed for DIP devices of various sizes as well as performing other operations.

It is possible to provide an apparatus in which only straightening and alignment takes place.

Considering first, however, the basic components of the apparatus can straightening and alignment in terms of function, the apparatus shown in Fig. 18 comprises a main housing 10' pivotally mounted on a pedestal or base 12' . The housing 10' is selectively adjustable relative to the base 12' to dispose the upper face 10a of the apparatus at a desired inclined angle, for example, from 35° to 55° so that DIPS can move through the various stations by gravity.

An elongated trackway T' is mounted on the upper face 10a of the housing. A DIP loading station SL' is located at the upper end of the trackway T' having a pivotally mounted loading cartridge holder for supporting the tubes within which the DIPS are carried for processing. When the tube is aligned with the trackway T', the DIPS to be processed discharge from the loading station S_L' directly to the upper end of the trackway T' , where as illustrated in Fig. 25, the DIPS straddle the trackway T' so that their leads or pins P' are disposed on either side thereof. The DIPS are retained on the trackway T¹ by an elongated adjustable upper guide and clamping rail assembly CR' which, in the operative position shown in Fig. 20, is spaced relative to the trackway T' to allow free movement of the DIPS along the trackway T' .

An escapement station S_e' is located downstream of the loading station S_j the function is to permit discharge of one DIP device at a time through the various other stations downstream of the escapement station S_e' . Single DIP devices discharged from the escapement station S_e' are moved by gravity to the pin straightening station S_s' where a DIP engages an index pin to properly position the DIP device relative to the pin straightening mechanism during a pin straightening cycle. The pin straightening station includes a pair of cooperating lead straightening heads comprised of a series of blades of the general profile shown in Fig. 30 which engage between the pins P¹ while the DIP device is still in an unsecured or floating mode. At this point in the cycle, the DIP device is clamped to the trackway T by the guide and clamping rail assembly CR' . The pin straightening heads are then oscillated to effect the straightening action and align the pins relative to the vertical plane V'-V.

DIPS so straightened at the pin straightening station S_s' are then released and move along the trackway T' to the coplanarity station S_c' located downstream of the pin straightening station S_s' (see Figs. 29 and 33- 36). As the DIP device enters this station, it engages another locating pin which positions the DIP between a pair of coplanarity jaws. The pins of the DIP device lie in the bite of a pair of the coplanarity jaws. In this position the DIP device is again clamped to the trackway T' by the clamp and guide rail assembly C_R'. The jaws are then cycled in a predetermined pattern to engage the pads of the DIP device first in a downward stroke bending all the pads of the DIP device below a selected horizontal reference plane H'-H'. Then the pads are driven upwards to the desired horizontal plane H-H and the coplanarity jaws are returned to a neutral position. It has been found that this cycling procedure results in coplanarity of all the pads P_p' .

Upon completion of the coplanarity adjustment cycle, the positioning pin is retracted, the clamping guide rail CR is elevated so that the DIP device is now free to discharge by gravity to a discharge station TDg where the processed DIP devices are again accumulated in the elongated collection tubes.

A logic keyboard for operating the various mechanisms of the apparatus of the present invention in predetermined timed sequences is provided which is of relatively standard form. An example of a typical logic keyboard and circuitry for achieving the controlled operation described herein is shown in Linker United States Patent No. 4,686,637, entitled APPARATUS AND METHOD FOR LEAD INTEGRITY DETERMINATION FOR DIP DEVICES granted August 11, 1987.

There are instances where it is necessary to access the trackway T' while DIP devices are located in the escapement station S'_e. For example, due to power failure or jamming, it may be necessary to remove the clamping and guide rail assembly CR' . Thus, the apparatus includes restraining elements -^n the form vanes Rie located on either side of the trackway T' which normally are spaced from the DIPs to allow free movement of the DIPs on the trackway by gravity. However, in the event of a power failure the vanes R'_e are released to a position to engage the DIP devices on the trackway and to retain them even when the guide and clamping rail assembly C_R' is displaced from its normal operating position and would no longer function to encapsulate DIPs on the trackway. A manually operable system is provided for removing the clamping and guide rail assembly C_R' if necessary, in the event of a power failure or jamming for access to internal parts of the machine inaccessible when the clamp, and guide rail C_R' is in the operative position. This manually operable system is also useful when initially setting up the apparatus, for a particular DIP device.

The apparatus includes a tube discharge station T'ds at the lower end of the trackway to receive processed DIP devices.

There are a number of photo-electric sensing cells P'_e located in the guide rail assembly which are aligned with the trackway T' and track the path of DIP devices through the apparatus. These photo-electric sensing devices function in the overall logic circuit to trigger the desired mechanical function of the machine in the manner described herein. These sensors act in pairs, one to project a beam and the other to receive the beam in a conventional fashion. Fig. 21 schematically shows the functioning of the escapement mechanism for the different size DIP devices ranging from between eight (8) pin device to a twenty-eight (28) pin device.

Considering now more specifically the details and structural arrangement of the escapement station S.e, and with particular reference to Figs. 20 and 21, there is provided a series of escapement pins 16', 18', 20' and 22' mounted in the clamping and upper guide rail housing 24' for reciprocating motion therein. The pins are mounted for reciprocating movement by spring biased air actuator assemblies 16a', 18a', 20a', and 22a'. The lead pin 16' is an index pin for all DIP sizes and functions to retain the line of DIPS at the escapement station S'_e in the manner illustrated. The other three pins, 18", 20', and 22* are designated clamping pins and are selectively actuated in unison with the stop pin 16' depending on the size of the DIP device being run. For example, index pin 16 ' is only retracted to release a DIP device when one of the three remaining clamping pins is in an operative or clamping mode. This produces release of one DIP device at a time from the escapement station S_e' to the pin straightening station S_s' .

A single DIP device released from the escapement station S_e' moves down the trackway T' until it engages a second indexing pin 26' at pin straightening statio The indexing pin 26' as best shown in Figs. 20 and 29 is aligned with the straightening heads 28a' and 28b' so that it positions the front edge of a DIP device in the correct operative position for leafing inter-engagement of the blades 34' in the spaces between the DIP device pins P'. The location of the indexing pin 26' need not be totally precise so long as it generally orients the DIP device so that each of the blades can engage in a space between the DIP device pins. The DIP device is in a floating condition on the trackway T* in this part of the straightening cycle.

The pin straightening station S_s' comprises a pair of cooperating pin straightening heads 28a' and 28b'. Each head is of identical construction and comprises a U- shaped block 30' having an elongated key slot 32' in its base and a plurality of elongated straightening blades 34'. The blades 34' comprise an elongated body 36' having a depending lug 38' which keys in the slot 32 ' in the housing to align the blades so that the straightening blades teeth 40' are aligned in the manner shown in Fig. 29". The blades are kept in a tight abutting side to side relation by means of set screws and opposing upright end portions of the block 28'. The blades are anchored in the block by means of a cap 42' . Even though the straightening heads comprise a plurality of discrete fingers which are keyed in place so that the finger tips align, the finger assembly may comprise a unitary integral element comprised of a plurality of finger tips of essentially the same configuration as those shown and described herein.

Means are provided for cycling the heads 28a', 28b' in a predetermined sequence when a DIP device is located at the straightening station S_s' to effect straightening the leads or pins P relative to the vertical plane V'-V' . Figs. 23 and 25 show the "home" position of the straightening heads. The heads 28a', 28b' are moved downwardly initially in the straightening cycle to a point where the tips 40a¹ of the blades 36' are located intermediate the pads and the shoulder of the pins of the leads as shown in Fig. 26. With the straightening heads in this position, the guide rail C_R' is actuated downwardly to clamp the DIP at the straightening station S_s' against the trackway T so that it is immovable. Thereafter, the heads 28a', 28b' are oscillated in a horizontal plane parallel to the axis of the trackway T' to bend each of the leads to either side of its true vertical alignment. It has been observed that this action allows for spring back and aligns each of the pins P in the vertical plane V'-V in the desired parallel orientation of the pins as viewed from the side of a DIP device. In a typical DIP device the spacing between the pins P' is 0.050 inches and the pins are approximately 0.014 inches wide. Thus in a typical cycle the pins are displaced about 0.003 inches from the vertical plane V- V to either side.

Considering now more specifically the means for effecting cycling and actuation of the straightening heads 28a', 28b' in the manner described above and with reference to Fig. 23, the head, are mounted on elongated slides 50a' and 50b' which are slidably engaged in slide retaining blocks 52a' and 52b'. The elongated slides 50a' and 50b' are connected at their lower ends with a cross head 54' (see Fig. 23) which in turn is connected to a piston-cylinder actuator 56' . Accordingly cycling of the piston-cylinder actuator 56' effects reciprocating up and down movement of the cross head 54' , the connected slides 52a' and 52b', and the pin straightening heads 28a' and 28b' to cycle the heads from the home position shown in Fig. 25 to the straightening position shown in Fig. 26.

The heads 28a' and 28b' are preferably oscillated in opposite directions relative to one another through a mechanism best shown in Figs. 27, 28 and 33 in a direction parallel to or aligned to the trackway T' .

Thus each slide 50a', 50b' is mounted in two independent slide retaining guide blocks 52a', 52b' and each retaining-block is mounted on a pair of stub shafts 62a', 64a', 66b', 68b¹, which in turn are slidably mounted at their outer ends to fixed frame members 70' forming a part of the main housing. The guide blocks 52a', 52b' are adjustable relative to the stub shafts 62a', 64a', 66b', 68b' and set screws are provided to hold the guide blocks in a fixed position on the stub shafts. The lower stub shafts 64a' and 68b' are connected to a yoke assembly broadly designated by the numeral 74' (see Figs. 23, 28 and 30). The straightener heads are connected together for the oscillating movement described at the lower stub shafts 64a' and 68b' via the yoke assembly 74' which comprises an upstanding vertical shaft member 76' mounting cross shafts 78', 78' connected at their outer ends to universal rotary bearing links threaded to the terminal ends of the stub shafts 64a' and 68b'. The vertical shaft 76' is rotatably mounted in bearings in the trackway T' and baseplate B_p' as best illustrated in Figs. 27 and 28. Thus oscillating movement of the cross shafts 78', 78' imparts back and forth oscillating movement of the straightener heads through the stub shaft 64a' and 68b'. The vertical shaft 76' is connected at its lower end in a non-rotatably fashion to an elongated actuating link 80'. The outer ends of the link 80 abut adjustable pivot limiting assemblies 82a' and 82b'. (See Fig 32) Each assembly includes a spring biased positioning head 83a', 83b' abutting arcuate cam elements 85a' , 85b' on the outer terminal ends of the connecting link 80' and a vernier adjustment 84' determines the allowed pivotable movement of the link 80' about an axis through the shaft 16' . The positioning head is spring returned to always maintain contact with the cam follower 85a', 85b'. A piston- cylinder actuator 90' cycles the link 80' .

During what may be termed the initial DIP alignment portion of the lead straightening cycle wherein the DIP devices are floating on the trackway T' and the straightening fingers or blades 40' are leafing between the leads of the DIP device, moveable support means is provided to prevent bending or damage to the leads in this phase of the cycle. To this end, a pair of support plates 92a', 92b' are pivotally mounted on opposite sides of the trackway at the lead straightening station S_ε' and are normally spring biased inwardly so that they lie flush against the trackway and wherein the upper faces 92c' define support surfaces for the pads of the lead. The support plates 92a', 92b' are pivotally mounted at their lower ends to slide blocks 94a' and 94b' and are nested inside the slide blocks as best illustrated in Fig. 23. The slide blocks 92a', 92b' are biased upwardly by pins 96a' and 96b' of air cylinder 98a' and 98b'. In this manner, the slide blocks 92a', 92b' are normally biased gently upwardly to lightly engage the upper edges of the support blocks against the pads Pp' of the DIP device at the straightening station. The support plates are normally spring biased inwardly against the opposing faces of the trackway T' and have a relief edge at their lower end to permit outward pivoting movement shown in Fig. 23 when the straightening blades 40' are moved to their operating position shown in full lines in Fig. 24 and 26. Figs. 25 and 26 show the position of the support plates described above. This type of arrangement is important to provide a firm but yielding support for the pads P_p' during the time the separating blades are moving in the gap or breach between adjacent pins of the DIP device and before locking the DIP device in place for the oscillating action for straightening the pins.

The particular configuration of the straightening blades and particularly the shape of the teeth 40a' formed on one end of each blade is important in achieving the desired combing and straightening action described above. Thus, the tip 40b' of each tooth 40a' has a depending pick like shape. The particular geometry of the tip of the blade 40' is best shown in Fig. 16 wherein the pick like shape is generally triangularly shaped. The mid point of the tip 40b' is of a greater cross section as at 40c' than the tip 40b'. By this configuration the mid point of the teeth fill the space between the leads to insure a good straightening action when the heads are oscillated. In other words, the pick like structure of the tooth permits initial entry of the blades to the spaces between the pins without damage and the large mid-section 40c' of the blade then fills the gap between adjacent leads so when the heads are actuated, the displacement of the leads or pins P* to either side of the vertical plane V'-Vtakes place during the straightening action. The prese^'nt apparatus can be easily modified to replace the trackway and the heads can be adjusted outwardly to accommodate a wider trackway. As best shown in Figs. 23 and 27, the slide guides and guides for the straightening heads are movable outwardly relative to one another to accommodate a larger trackway. It is noted that the lower end of the slides 50a' and 50b' are mounted by keys 102' which engage in slots 51' having sufficient play to accommodate trackways of various widths. This connection permits the necessary relative displacement of the slides outwardly relative to one another or into and out of the plane of the paper with respect to Fig. 27.

The configuration of the straightening heads 28a' and 28b' and particularly the mounting of the separating blades 34' provides the advantage that the blades 34' can be easily replaced if necessary to accommodate DIP devices having leads P' that are spaced differently and require a different set of blades. In other words, the head assemblies have a universal application to DIP devices irrespective of the gap between adjacent pins. The changeover is simply accomplished by removing the top cap 42' and inserting the blades 34' having the appropriate spacing for a given DIP device. The machine is adaptable from an eight (8) pin to a twenty eight (28) pin DIP device as shown in the drawings.

When the oscillating cycle of the straightening heads is completed, the guide rail assembly C_R' clamping the DIP device at the straightening station is retracted as well as the second indexing pin 26' whereby the DIP device moves by gravity to the next adjacent coplanarity station S_c' .

Consider now the coplanarity station S_c' , the shown in Figs. 33-36

The coplanarity heads 200a' and 200b¹ are connected to a common slide 202' which is mounted for reciprocating movement by a piston-cylinder actuator 204' connected to the base plate B_p' . The slide 202' is confined for sliding movement in the pocket of a slide housing 206' formed by a number of front panel 208' and rear panel 210' in turn connected to the base plate B_p' by mounting blocks 212' and 214'. A pair of micrometers 216' and 218' are mounted on one sidewall of mounting block 214 and axially aligned and opposed are two adjustable spring biased piston heads 220' and 222" mounted to block 212'. Intermediate the micrometers heads 216', 218' and the spring biased piston heads 220' , 222' are adjustably mounted limit blocks 224' and 226'. Limit block 224' is positioned between micrometer head 216' and spring biased piston head 220' and limit block 226' is positioned between micrometer head 218' and spring biased piston head 222' . The limit blocks 224' and 225' are adjustably mounted to the front panel 208' of the fixed housing 206' by way of two diagonally opposed slots 228' and 230' formed in the front panel 208' and secured in a desired position by means of set screws 232' and 234'. The slots 228' and 220' form tracks for the blocking 224' and 226' to slide in. The slide 202' has a rectangular striker block 236' fixedly mounted to its front face by means of screws. The strike block 236' projects through a rectangular aperture 238' spaced midway between the diagonal slots 228", 230'. The slide then is free to move vertically between the lower surface of limit block 224' and the upper surface of limit block 225'. The vertical placement of the limit blocks 224' and 226' determines the upward and downward travel of the slide 202', and the coplanarity heads 200a' and 200b'. When a 2-way cylinder 201' is deactivated, the slide 202' and heads 200a' and 200b' also assume a rest or normal position that places the block 236 ' at the midpoint of the window 238' irrespective of the positioning of limit blocks 224' , and 226' . The rest or normal position of the slide 202' and heads 200a' and 200b' is accomplished by the following means with a reference to Figs. 35 and 36. The slide 202' has fixedly secured to its rear face a second rectangle positioning block 240' . The striker block 236' and the positioning block 240' are both secured to the slide 202' with the same mounting screws 242'. The positioning block 240' projects through a rectangular aperture 244' in the rear panel 210' of the slide housing 206'. As shown in Fig. 36, fixed rectangular edge blocks 246' and 248', are mounted on the left and right hand sides of aperture 244' and centrally located with respect to the aperture 244' . The slide housing 206' and positioning block 240' have the same cross sectional thickness, the upper and lower faces forming a common plane. Spring biased bearing blocks 250' and 252' span the upper and lower faces of the edge blocks 246' and 248' and centrally position, the centering block 240' between them when no force is applied thereby positioning the slide 202 ' and the coplanarity heads 200a' and 200b' in a desired rest position. The bearing blocks 250' and 252' are spring biased toward each other in the following manner. Rectangular anchor blocks 254' and 256' are secured to the rear panel 210' of the slide housing 206' by means of mounting screws 258'. Between each anchor block and bearing block there are positioned two springs 260'. Bearing block guide pins 262 ' are centrally positioned between anchor blocks 254' and 256' and bearing blocks to both guide and retain the spring biased bearing blocks 250' and 252' .

Having now described the specific structural details and actuating mechanisms for the coplanarity heads, consider now the action of the heads on a DIP device when it arrives at the coplanarity station S_c ' . A DIP device advances along the trackway T' by gravity and is brought to rest at the coplanarity station by engaging a second indexing pin 27' . The coplanarity heads at this time are in a rest position (See Fig. 34). The photo detectors Pe' sense the presence of a DIP device at the coplanarity station and effect actuation of the clamping guide rail assembly C_R' to securely clamp the DIP device to the trackway T for the cycling of the coplanarity heads in the manner described above. The coplanarity heads as described previously, first engage all the pads and bend them about the shoulder point connection to one side of the desired horizonal plane H'-H'; first downwardly of the plane H'-H' to a lower limit position. The limit blocks just described, which are selectively adjustable determine the lower limit position of the coplanarity heads. This mechanism provides a simple and precise means for adjusting this lower limit position. The coplanarity heads are then cycled upwardly to a position where the lower faces of the pads P_p' lie in the plane H'-H' . The piston cylinder actuator then is deactivated whereby the spring 260' returns the coplanarity heads to the neutral or home position shown in Fig. 34. The upper and lower limit positions are simple to adjust by simply loosening the screws to 232' and 234'. The fine tuning adjustment can then be made through the verniers 216' and 218', the blocks of course being held firm during adjusting movement by the spring biased pistons 220' and 222' . After a new adjustment has been accomplished which adjusts the gap between the striker plate and the blocks 224' and 226', the screws 232' and 234' are simply re-tightened.

Another feature of the present invention is shown in Figs. 37 and 28. The mechanism illustrated here is useful in facilitating disassembly of the clamping and guide rail assembly C_R' in the event of a power failure. This mechanism is used for initially setting up the machine for a given DIP device and additionally permits access to the machine in the event of a power failure or malfunction such as jamming of the DIP device. Thus this mechanism is important for initial set up and trouble shooting of the--apparatus.

The clamping and guide rail assembly is mounted in a cantilevered support frame 300' on the base of the main frame Bp'. The clamping and guide C_R' rail assembly is adapted for adjusting longitudinal movement relative to the trackway T' to permit, for example, adjustment of the escapement S_e' indexing pin, at the straightening station, (see Fig. 28) and to this end is mounted in linear bearings 302'. The guide rail assembly C ' has a rearward extension 304' which is mounted in a complementary opening 306' in the cantilevered support

300' to accommodate vernier adjustment means of the type shown in Fig. 28. This adjustment comprises a vernier mounted piston micrometer head 308' which bears against the block 304' . The adjustment is made against a spring bias backing support 310' .

The cantilevered support 300' includes an upstanding fixed support element 312' mounted on the base. The cross arm 314' of the cantilever support which carries the guide and clamping rail is connected to an actuating system via a spring biased tang 316' engaging in a slotted block 318' mounted to the cross arm 314'. The block 318' is connected to a carriage 320' by means of tang 316'. The gap between the upper surface of trackway T' and the underf ce of the guide rail 319' of assembly C_R' is selectively adjustable and controlled by a screw member 322' which engages the top of the carriage 320' and back of piston-cylinder 325' to limit the throw of the piston cylinder actuator. The carriage 320 moves vertically in support element 312' and cross arm 314 is guided in linear bearings 324'. Ajustment screw 323' engaging piston-cylinder actuator 325' provides means for controlling relative spacing between guide rail 319' and upper surface to trackway T (See Fig. 39).

With reference to Fig. 37, it can be seen that in normal vertical adjusting movement of the clamping and guide rail assembly C_R' to clamp and release the DIP devices in the various manners described above, the cross head 314', block 318' are keyed integrally via tang 316' to the piston cylinder actuator 320'. The actuator as best shown in Fig. 38 is mounted for this vertical adjusting movement in linear bearings 324' . Further in normal operation, the air cylinder rod 328' is engaged and maintains the parts in the inter-locked relationship described. In the event of a malfunction or loss of air pressure, air cylinder rod 328' releases downwardly and thus tang 316 ' can be withdrawn from its seat in block 318'. Accordingly, piston-cylinder actuator 320' may be retracted manually by a knob actuator 326 ' thereby releasing block 318' and permitting manual disassembly of the cross arm 314' and its associated clamping and guide rail assembly C_R' . This permits the trackway and the associated part of the cantilevered assembly to be removed vertically and upwardly and away from the trackway and apparatus. In normal operation, air cylinder rod 328' prevents displacement of the tang 316'. In the event of power failure, this pin 328' automatically drops to a release position permitting the manual disassembly described above. Note that tang or block 316' is normally spring biased to the locking position by spring 330'. (See Fig. 36)

The coplanarity system of the present invention works the leads in such a manner to insure maintenance of the desired so called lead stand off height necessary for proper installation. This height designated H_jj' in Fig. 17B is the distance between the lower face of the body portion B' and the plane H'-H' .

It is contemplated that a variety of DIP devices can be processed by the apparatus of the present invention. The invention is designed to locate those DIP devices which do not meet quality control criteria and to either reject or repair those defective DIP devices. Examples of defective devices are shown in Figs. 4A, 4B and 4C. DIP device Dl shown in Fig. 4A, is shown having straight and equally spaced leads but is lacking integrity by having one broken lead LI. Otherwise, the spacing between leads is within specification. Nevertheless, this DIP device cannot be repaired and must be rejected by the apparatus.

DIP device D2, shown in Fig. 4B, includes leads L2, L3, and L4, at either terminal end of device D2 which are bent or at an angle to a vertical horizontal reference plane V,V of DIP device D2. These leads are not so far out of specification that they cannot be straightened in lead straightening station 22. Similarly, leads L5, L6, and L7 shown in Fig. 4C are out of coplanarity with respect to the horizontal reference plane H,H. These out of plane leads can be adjusted in coplanarity adjustment station 23.

Turning now to Fig. 5, the sequential operations performed on discrete DIP devices as they flow by gravity from the supply tube 13 to the reject or accept collection tubes 16a, 16b, 16c are illustrated. Shown also is the coupling to the associated computer and output stations.

Fig. 5 describes the operation of the apparatus of the present invention schematically. DIP devices are received and form a train of DIP devices on the track, stopping at the first pin stop. Single DIP devices are released from the DIP train pin stop. The DIP device then travels to the second pin stop, in which a lead to lead scan is performed to determine the existence and spacing of each lead. This data is then sent to a first comparator which compares the data for the specific lead with predetermined values which have been derived from a predetermined pattern.

It is noted that a variety of information can be obtained in this manner. A central processing unit can be programed by a keyboard to store a variety of information. In addition to lot numbers and other information, one could determine that a particularly lead location was experiencing greater failure than others, which information could be used to improve the manufacturing process.

After the comparison has been made between the actual data on the lead to lead scan with a predetermined pattern, an accept or reject decision is made. DIP devices would be rejected if a lead were missing or so badly skewed that it could not be straightened. Information that this particularly DIP device has been rejected is sent to the sixth and final stop pin on the track, so that the shuttle will deposit the rejected DIP in the appropriate collector tube.

The DIP device then slides down to the second station, a coplanarity test station where the DIP device is stopped by the third stop pin. Again, coplanarity of the various leads is evaluated and compared in a second comparator to determine coplanarity. This information is again provided to a central processing unit and a decision is made to accept or reject the individual DIP device by comparing the actual values with predetermined standards or .pattern. Again, a rejected DIP is identified to the shuttle so that it can be placed in the rejected DIP device collector tube.

Upon completion of the testing and designation of a accept or reject position, the DIP device then proceeds by gravity to a fourth stop pin at the lead straightener station. If the DIP device has been rejected, the lead straightening unit is not engaged. Similarly, if the first and second comparators have judged the particular DIP device to be within acceptable specifications, the lead straightening apparatus is not engaged. If, however, the first comparator indicates that the leads are not within the predetermined acceptability pattern but are within a range which permits straightening, the lead straightening station combs through the lead to produce an acceptable product.

The DIP device then leaves the lead straightening station and proceeds to a fifth stop pin at the coplanarity adjustment station. Here, again, rejected DIP devices and DIP devices which have acceptable values for a lead scan and coplanarity scan are not subjected to a coplanarity adjustment but merely pause at this station during the sequential travel of the DIP device through the apparatus. If, however, the second comparator determines that coplanarity is out of specification but can be adjusted, the coplanarity station functions to adjust the coplanarity of this particular DIP device. Also, if the particular DIP device has been subjected to lead straightening in the lead straightening station, it also will be subjected to coplanarity adjustment to ensure that alignment of the leads spacing has not had a detrimental effect on coplanarity. Thus, in the preferred embodiment, the coplanarity adjustment station will operate on the DIP device if either or both scanning stations indicate the need for adjustment. The DIP device then leaves the coplanarity adjustment station and arrives at the sixth stop pin, at the output station. Here, the DIP device is placed in the appropriate tube collector, depending upon whether it is to be rejected or accepted.

Turning now to the detailed operation of the apparatus of the present invention, a fragmentary side elevational view is shown in Fig. 6 in which the various stations in the upper section 17 and lower section 18 are shown. DIP devices are carried on track 19 to the inlet station 26. The inlet station 26 is arranged to permit single DIP devices to be discharged from the inlet station 26, whereby the DIP devices move by gravity to each succeeding station downstream. An inlet station sensor directs light from a photodiode 31 through a prism 32 to a photodetector 33. Interruption of the flow of light through the prism 32 will indicate the presence of a DIP device. Stop pins 34a through 34d are programmed so that one or another of the various stop pins will be used to release the DIP device depending upon the length of the specific DIP device. Stop pin assembly 34 is programmed to sequentially release DIP devices upon command from the central processing unit, for example.

The DIP device then proceeds to the first station, which is lead to lead scan station 27. The sensor again comprises a photodiode 36, prism 37, and photodetector 38 which activates the first station pin 39. At station 27, as will be described hereinafter, a scanning means is moved axially along the length of the device to provide a signal upon intersection of each of the leads extending from the device. Comparison of the signal with a predetermined signal determines the existence and spacing of each lead so that an accept, repair or reject signal can be generated, as determined. Next, the DIP device proceeds by gravity down the track 19 to the second station 28 where coplanarity is evaluated. Again, a photodiode 41, prism 42 and photodetector 43 form a sensor which operates stop pin 44. In this station, the coplanarity of the DIP device is measured and compared to a predetermined standard to again generate a pass, fix or reject signal, depending upon the comparison. Next, the DIP device continues on track 19 to the straightening station 22. Arrival of the DIP at the third station 22 for straightening, if necessary, is again signalled by interruption of light flowing from the diode 46 through prism 47 to photodetector 48, thereby actuating stop pin 49.

Similarly, the DIP device proceeds to the fourth station 23 for coplanarity adjustment, if necessary. Photodiode 51, prism 52 and photoreceptor 53 form a sensor for the fourth station 23, activating stop pin 54 upon arrival of a DIP device at that station.

In order to ensure the accuracy of any measurements and adjustments being made by the apparatus of the present invention, it is necessary to ensure that the DIP devices are firmly placed and held on the track 19 as they progress from the first through the fourth stations. As can be seen in Fig. 6 there is a small clearance between track 19 and clamping rail 21. The DIP device straddles the track 19 with its leads extending out from the body and perpendicular to the direction of travel. At each point when the individual DIP device reaches a sensor, such as would be indicated by photodetector 38 no longer receiving light from photodiode 36 through prism 37, pin 39 extends to stop the particular DIP device. At the same time, clamping rail 21 extends down from the input end to the output end and across both the upper section 17 and lower section 18 to clamp any DIP devices contained on track 19. It can be seen that a DIP device will pause sequentially at each station 27, 28, 22 and 23 as it progresses through the apparatus, even if no activity such as a straightening or adjustment of coplanarity is desired. Normal throughput time for a DIP device through the apparatus will be determined by the time necessary for scanning in the first station 27, where the integrity and spacing of the leads is determined. The second station 28 which measures coplanarity operates at substantially the same or faster speed than first station 27. The remaining portion of the apparatus does not add to the time of a complete cycle for an individual DIP device if the DIP device passes the specifications assigned to first and second stations 27 and 28. However, when either straightening or straightening and coplanarity is necessary, additional time may be taken during the straightening or adjustment steps. Even during this time, however, DIP devices at the first and second stations 27 and 28 are being performed.

As has been noted above, the third station 22, straightens leads which are out of alignment, and the fourth station 23, adjusts the coplanarity of the leads.

A particular DIP device arrives at station 27, as signalled by interruption of light passing from photodiode 36 through prism 37 to photoreceptor 38. Stop pin 39 operates to stop the DIP device, as shown in Fig. 6, the DIP device then becomes firmly clamped in place between track 19 and clamp rail 21, clamp rail 21 is lowered in the direction of the arrow as shown in Fig. 10, to firmly locate and align DIP device D10.

Stop pin 39 will always stop the DIP device at the extreme downstream lead, which, of course, is the first lead to intercept the light beam passing through prism 37. In this manner, a variety of different DIP devices having different lengths and different numbers of leads can be processed with the same equipment. Since the DIP device itself is not centered along the axial direction but rather is stopped at the first lead location, scanning and operations can take place starting at that first lead, regardless of the number of leads which extend from the DIP device.

Figs. 7 through 11 describe various details of the first station 27 which functions to scan the leads of the DIP device for existence and spacing between leads.

As soon as the DIP device arrives at the first station 27, motor 56 begins to drive spur gear 57. Motor 56 and spur gear 57 are mounted on a fixed plate 58. Spur gear 57 turns larger gear 59, causing the jackscrew 61 to transmit motion to a linear direction. Limit switch 62 and sensor 63 limit the maximum amount of scan head travel.

Jackscrew 61 drives a slidable carriage 64 which is carried on fixed plate 58 by linear bearings 66. As the slidable carriage 64 moves linearly, the rack 67 engages shaft 68 of encoder 69, and signals the location of slidable carriage 64. This location is identified with respect to time as the motor 56 drives the carriage 64 over a preset length. The length may be set by limit switchs 62, 63 or may be programmed into the central processing unit. Encoder 69 is mounted on mounting block 71, which in turn is biased against the rack 67 by leaf springs 72. Leaf springs 72 serve to protect transmission of vibration to the encoder 69 which would affect the accuracy of the measurements as motor 56 moves the slidable carriage 64 back and forth from start to stop positions.

Turning now to Fig. 9, it can be seen that the jackscrew 61 is driven by large spur gear 59 to move the slidable carriage 64. Block 73 and bearings 74 support jackscrew 61 and translate motion to the slidable carriage 64. Jackscrew 61 is supported at its other end by fixedly mounted nut 76 attached to bracket 77.

As the slidable carriage 64 moves along the axial length of a DIP device, a scanner transmits signals to the encoder 69. The scanner, shown best in Fig. 10, comprises a light source 78, such as a diode, which transmits light to prism 79. Light then exits prism 79 at a point near track 19 and clamp rail 21. The light is received by detector 81 after passing through a very tiny hole 82. Hole 82 and detector 81 are aligned at the very end of prism 79 closest to the track 19. In fact, track 19 includes a cut out portion 83 to permit the edge of the prism 79 to get as close as possible to the leads on the DIP device D10.

As the scanning station 27 begins to move as motor 56 drives jackscrew 61 as previously described, photodetector 81 detects the leading edge of each lead. An immediate voltage drop occurs as soon as the leading edge of the lead intersects the light path through hole 82. When this voltage drop is detected by detector 81, a signal is sent to the central processing unit which also receives the location as identified by the encoder 69. After the scanning station 27 passes the first lead, the intensity of the light on detector 81 is increased again until the second lead causes a voltage drop as light is restricted by the leading edge of the lead. This process continues until all of the .leads have been scanned on the DIP device.

As shown in Fig. 11, DIP device D10 is held by pin 39. The DIP device scanning station moves past the various leads on D10 until a distance T has been traveled. Distance T can be programmed into the device or be determined by limits switches, such as limit switch 62, 63 in Fig. 8. Any leads which are absent, will, of course, cause an exceptionally long movement of the scanner station 27 without reporting a lead location to the central processing unit or CPU. The CPU can be programmed to automatically reject any DIP device which fails to report a signal over a period of time which would indicate that a lead is either missing or extremely far out of alignment. This sort of programming can decrease the throughput time, to thereby increase the efficiency of the apparatus.

«

After the DIP device leaves the first scanning station 27, it proceeds to a coplanarity test station 28 as shown in Figs. 12 and 13. A DIP device carried by track 19 is positioned at coplanarity test station 28.

Shown in Fig. 12 is a similar device in which tines 84 are in circuit making contact with conductive leads on the upper portion 86 of block 87. When the individual leads of DIP device contact the tines 84, as block 87 is moved up to cause such interaction, a signal is sent indicating the arrival of that particular lead at the particular point in space. Once again, an encoder is employed to locate a particular point in space at which the signal is sent indicating arrival of the lead in contact with the tine to break the electrical circuit.

Block 87 -is itself attached to a slide block 88 which is in contact with sensor button 89 of encoder 91. Motor 92 drives jackscrew 93 and bracket 97, to uniformly move slide block 88 in an upward direction until the tines 84 have intersected all of the leads on the DIP device or until a limit switch has been reached. Jackscrew 93 is in engagement with a fixed nut 94 which in turn is fitted in bracket 97. Suitable bearings are provided to ensure movement of the slide block 88, to prevent transmission of vibrations or "noise" to the encoder 91.

The details of the coplanarity inspection heads are shown in Figs. 14 and 15 in relation to a gull-wing device D14 having leads L14. DIP device D14 has been stopped by pin 44 as leads L14 extend over a plurality of tines 84, with one tine aligned over each lead. Clamp rail 21 firmly positions the DIP device D14 as the tines are raised by movement of slide block 88 as previously described, so that block 87 moves the tines to position shown by tine 84a, intersecting a lead L14. The circuit between tine 84 and block 86a, shown in dot and dash line, is broken, sending a signal to indicate the location of the''individual^' lead L14.

Thus it can be seen that the inspection stations 27 and 28 of the present invention provide one hundred percent inspection of DIP devices. The apparatus of this invention accepts, repairs or rejects DIP devices. Time is spent straightening or aligning only those DIP devices which need repair. An operations system has been provided which is suitable for all manufacturing and assembly operations.

While particular embodiments of the present invention have been illustrated and described herein, it is not intended to limit the invention. Changes and modifications may be made therein within the scope of the following claims.

Claims

CLAIMSWhat is claimed''is:

1. Lead scanning station apparatus for scanning the lead to lead integrity of electronic devices having an axial length and lead extending from the side thereof, comprising: track means for moving individual devices axially along a path; a scanning station on said path, including stop means for stopping each of said devices at a predetermined location on said path and also including holding means for positioning said device in a scanning orientation;

scanning means movably positioned at said station for scanning axially along the length of said device and providing a signal upon intersection with each lead extending from said device; and

comparator means for comparing actual signals from said scanning means with predetermined signals to determine the existence and spacing of each lead with respect to a predetermined pattern, said comparator means providing a signal based on said comparison for each device.

2. The apparatus of claim 1 wherein said comparator means provides an acceptance, repair or reject signal based upon comparison of said actual signals with said predetermined pattern.

3. The apparatus of claim 1 wherein said scanning means and comparator means include an encoder means for precisely locating said scanning means with respect to a known location as said scanning means moves axially along the length of said device.

4. The apparatus of claim 3 wherein said scanning means includes optical means for providing an optical light path, including means for aligning said light path to intersect said leads as said scanning means moves along the length of said device and generate said signal upon intersection of said optical light path with said lead.

5. The apparatus of claim 4 wherein said optical scanning means includes a light source, a prism for directing a light path closely adjacent said device and aligned to intersect leads extending from said device, and light receiving means responsive to the intensity of light directed from said prism.

6. The apparatus of claim 3 wherein said scanning means includes slidable carriage means including a drive means for moving said carriage axially along the length of said device^".

7. The apparatus of claim 6 wherein said carriage means and said encoder means include rack and gear means for locating said carriage with respect to a fixed reference.

8. A method for scanning the lead to lead integrity of electronic devices having an axial length and lead extending from the side thereof, comprising the steps of:

moving individual devices axially along a path;

stopping each of said devices at a predetermined location on said path and positioning said device in a scanning orientation;

scanning axially along the length of said device and providing a signal upon intersection of leads extending from said device; and

comparing actual signals from said scanning means with predetermined signals to determine the existence and spacing of each lead with respect to a predetermined pattern, and providing a signal based on said comparison for each device.

9. The method of claim 8 wherein said comparing step provides an acceptance, repair or reject signal based upon comparison of said actual signals with said predetermined pattern.

10. The method of claim 8 wherein said scanning precisely locates said scanning means with respect to a known location as said scanning moves axially along the length of said device.

11. The method of claim 10 including the step of providing an optical light path to intersect said leads while scanning^•moves along the length of said device to generate said signal upon intersection of said optical path with said lead.

12. The method of claim 11 wherein said optical path 15 scan, directed by a prism to a position closely adjacent said device and aligned to intersect leads extending from said device, and light receiving means is responsive to the intensity of light from said prism.

13. A system for inspecting and straightening the lead integrity and coplanarity of electronic devices having an axial length and leads extending therefrom, comprising:

track means for defining a path for said devices along said axial length from an inlet, sequentially to a first station for lead to lead scanning, a second station for coplanarity scanning, a third station for lead to lead straightening, and a fourth station for coplanarity adjustment and to an output station;

clamping rail means aligned with said track for cooperatively holding said devices at any location on said track;

stop means for stopping said devices along said track at each of said stations and activating said clamping rail means; and

controller means for sequentially activating said first and second station to provide first and second signals indicating acceptance, repair or rejection of individual devices, said controller means activating both of said third and fourth station upon generation of a repair signal from either or both of said first and second stations, said outlet station adapted to separate devices upon receipt of a signal indicating acceptance or repair from devices upon receipt of a reject signal.

14. The system of claim 13, wherein said first station for scanning the lead to lead integrity of electronic devices having an axial length and lead extending from the side thereof comprises:

track means for moving individual devices axially along a path;

a scanning station on said path, including stop means for stopping each of said devices at a predetermined location on said path and also including holding means for positioning said device in a scanning orientation; scanning means movably positioned at said station for scanning axially along the length of said device and providing a signal upon intersection with each lead extending from said device; and

15. The system of claim 14 wherein said comparator means provides an acceptance, repair or reject signal based upon comparison of said actual signals with said predetermined pattern.

16. The system of claim 14 wherein said scanning means and comparator means includes an encoder means for precisely locating said scanning means with respect to a known location as said scanning means moves axially along the length of said device.

17. The system of claim 13 wherein said second station inlcudes a plurality of individual tines aligned to intersect leads on said device upon movement thereof in a plane toward said leads, each of said tines being adpated to provide a signal indicative of the position of said leads with respect to a predetermined pattern, said second station including coplanar comparator means for generating a signal responsive to a comparison between signals generated by said tine and said predetermined pattern.

18. The apparatus of the type described for aligning the leads of electronic devices having a body portion and plurality of leads extending from the body portion having pads at the free terminal ends comprising:

means for positioning an electronic device at a lead straightening station,

a pair of lead straightening heads comprised of a plurality of fingers engagable between the leads on opposite sides of the electronic device;

means for actuating the heads relative to the electronic device through a straightening cycle including a first phase where the fingers engage between leads of the electronic device while in a floating condition and a second phase after the electronic device is clamped in place on a support surface to pivot the leads on either side of a plane extending transversely to the body portion and thereby align each of the leads relative to this plane; and

coplanarity means for positioning the pads of the leads so that_.they all lie. in a common plane.

19. The apparatus as claimed in Claim 18 wherein the means for positioning a single electronic device at the lead straightening station comprises a series of pins spaced along the trackway including a first indexing pin and a series of escapement pins up stream of the straightening station which retain a line of electronic devices at the escapement station and release DIPs one electronic device one at a time to the straightening station.

20. The apparatus as claimed in Claim 18 wherein the fingers have of a pointed pick like hook portion which is tapered to facilitate insertion of the fingers between the adjacent leads.

21. The apparatus as claimed in Claim 18 wherein the means for clamping the electronic devices in a selected location on the trackway comprises a clamping guide rail assembly overlying the trackway and having actuator means for reciprocating the guide rail in an up and down fashion from ^~~&- position Overlying and slightly spaced above the trackway so that the DIP devices are free to move by gravity along the trackway and a lower position to clamp a electronic device in place.

22. The apparatus as claimed in Claim 21 wherein the guide rail actuator includes means for manual disassembly of the guide rail to access the trackway.

23. The apparatus as claimed in Claim 18 including means for adjusting the upper and lower limit positions of the coplanarity jaws.

24. A method for aligning leads of electronic devices having a body portion and a plurality of leads extending from the body portion having pads at the terminal ends consisting of the steps of:

positioning the tips of fingers of lead straightening heads between the leads of the electronic device while the DIP device is in a floating condition on a support surface,

clamping the electronic device to the support surface,

oscillating the straightening heads to move the leads to opposite sides of a predetermined first plane to align all the leads generally parallel to the first plane, and

engaging the pads and pivoting the leads in a second plane generally transverse the first plane to pivot the leads about the shoulder and thereby align them all in a common second plane.

25. A method as claimed in Claim 24 including the steps of feeding a plurality of electronic devices to a support surface wherein the straightening and the coplanarity stations are spaced along the support surface and feeding the electronic device selectively through the stations to insure one at a time processing at each station.