WO1999036945A1

WO1999036945A1 - Method and device for separating and transferring electronic components

Info

Publication number: WO1999036945A1
Application number: PCT/NL1999/000015
Authority: WO
Inventors: Willem Antonie Hennekes; Willem Adriaan De Boer
Original assignee: Fico B.V.
Priority date: 1998-01-13
Filing date: 1999-01-12
Publication date: 1999-07-22
Also published as: NL1008018C2

Abstract

The invention relates to a method for separating electronic components, such as semi-conductors, from a lead frame and transferring the separated products to a product discharge carrier, wherein an electronic component separated from a lead frame is placed on a product transport carrier and subsequently transferred from the product transport carrier to the product discharge carrier. The invention also relates to a device for separating electronic components, such as semi-conductors, from a lead frame and transferring the separated products to product discharge carriers.

Description

METHOD AND DEVICE FOR SEPARATING AND TRANSFERRING ELECTRONIC COMPONENTS

The invention relates to a method and device for separating electronic components, such as semiconductors, from a lead frame and transferring the separated products to a product discharge carrier. Existing devices for separating and transferring electronic components can generally not alter the mutual distances between the individual electronic components. Devices exist with which the mutual distances between individual electronic components can be changed, but complex manipulators are required for this purpose. The drawbac of these complex manipulators is that they are costly, relatively susceptible to malfunction and have a limited capacity.

The present invention has for its object to provide an improved method and device for separating and transferring electronic components with which both processes are integrated and operation can take place with relatively simple means and at high speed.

The invention provides for this purpose a method as stated in the preamble, wherein an electronic component separated from a lead frame is placed on a product transport carrier and subsequently transferred from the product transport carrier to the product discharge carrier. In a preferred embodiment the method comprises the steps of: a) supplying a lead frame to a separator and, once the electronic components have been removed therefrom, discharging the remnant of the lead frame, b) supplying a product transport carrier to a first transfer position, c) engaging at least one row of electronic components for separating in the lead frame, d) separating the engaged row of electronic components from the remaining part of the lead frame, e) transferring the engaged row of separated electronic components to the product transport carrier in the first transfer position, f) repeating the steps c,d,e and if necessary step a until the product transport carrier is filled, g) displacing the loaded product transport carrier to a second transfer position, h) engaging a column of electronic components on the product transport carrier, i) transferring the engaged column of electronic components to a product discharge carrier, j ) repeating the steps h and i until sufficient electronic components have been placed on the product discharge carrier or repeating the steps g,h,i as soon as the product transport carrier is emptied, and k) discharging the filled product discharge carrier. The electronic components are herein preferably placed in a matrix pattern on the product discharge carrier. Using this method the mutual distances between the electronic components and the number of electronic components in the lead frame form no limitation in respect of the mutual distances between the electronic components and the number of electronic components on a product discharge carrier. To this end the electronic components are transferred in at least two steps whereby the mutual distances can be changed in stages. It is thus possible to change the mutual distances in different directions during separate transfer movements. A significant advantage in the method according to the invention is that the first change in mutual distances is combined with the necessary displacement of the electronic components when they leave the separator.

The product transport carrier is preferably driven during steps c-f with a stop-start movement. Using the movement of the product transport carrier it is thus possible to determine how great the distance is between successive groups of electronic components placed on the product transport carrier. The movement to be performed by a transfer device need hereby be less complex, thus enabling a relatively simple embodiment of the transfer device .

In another preferred method at least one product transport carrier circulates in a closed transport system. Since the product transport carriers fulfil an intermediary function, it is unnecessary to be able to remove them. A closed circulation system has the advantage that it is simple to mechanize, whereby the work-load can be limited when performing the method. Another advantage of a closed circulation system is that the danger of product transport carriers being lost, damaged or confused with product discharge carriers is small .

In a very advantageous form of the method the electronic components placed by one transfer movement in line on the product transport carrier enclose a substantially perpendicular angle with the electronic components engaged in line on the product transport carrier by a second transfer movement. In this preferred method the components are placed on the product transport carrier and once again removed therefrom in elongate groups. The direction in which the groups are placed lies perpendicularly of the direction in which the groups are removed from the product transport carrier. The advantage hereof is that the mutual distances between the electronic components can be changed in different directions during the two successive transfer operations. By first changing the mutual distances in for instance x-direction and then changing the mutual distances in y-direction, all possible desired patterns of electronic components can be made without complex transfer devices being required for this purpose. Because the desired pattern in which the electronic components have to be placed is built up in two steps, the transfer movements remain relatively simple and operation can take place at great speed. It is also possible to engage a plurality of elongate groups simultaneously and then place the individual groups sequentially on the following carrier. A transfer device hereby has to make fewer reciprocal movements between a pick-up position and a lay-off position.

It will be apparent that a plurality of processing steps are preferably performed at least partially simultaneously in order to enable high capacity separation and transfer of electronic components. The present invention also provides a device as stated in the preamble, comprising:

- a separator for separating electronic components from a lead frame,

- a first transfer device for engaging electronic components in the lead frame and displacing the separated electronic components,

- at least one displaceable product transport carrier for receiving the electronic components transferred by the first transfer device, - a second transfer device for engaging electronic components on the product transport carrier and displacing thereof,

- a support for a product discharge carrier close to the second transfer device, and - drive means for driving separator, first and second transfer devices and displacing the product transport carrier .

The method as described above can be performed mechanically in this device without very complex constructions being required for this purpose. The device is relatively simple to manufacture and little susceptible to malfunction. Because a number of functions are sub-divided into a plurality of separate operations, the separate components of the device required for this purpose are of relatively simple design. The device is consequently easy to maintain.

The device preferably also comprises a supply system for supplying lead frames to the separator, which supply system is also provided with a discharge for lead frame remnants which are left behind after the electronic components have been removed by the separator and the first transfer device. Mechanization of the supply further limits the work-load for separation and transfer.

An advantageous embodiment of the device comprises a transport system for displacing at least one product transport carrier which is provided with positioning means for positioned displacing of the product transport carrier with a stop-start movement during loading. By displacing the product transport carrier the position can thus be determined at which the first transfer device places electronic components on the carrier. The mutual distance at which the electronic products are placed on the transport carrier can be controlled by controlling this stop-start movement. The transfer device can herein always lay off the electronic components at the same position, whereby the transfer device can be constructed relatively simply. The first and second transfer device are preferably provided with a number of engaging members for electronic components lying in line. These can for instance be grippers or suction nozzles. A number of products placed in line can be engaged in simple manner with such a transfer device. The angle of the in-line engaging elements of the first transfer device relative to the product transport carrier during placing of electronic components preferably lies substantially perpendicular to the angle of the in-line engaging elements of the second transfer device relative to the product transport carrier during engaging of the electronic components. Because the mutual distances can be altered in one direction at the first transfer device, it is desirable to likewise be able to change the mutual distances between the electronic components in another direction, preferably one which lies perpendicularly of the first direction. This can be realized in simple manner by an engagement of the second transfer device on the electronic components which lies perpendicularly of the engagement by the first transfer device. The mutual distances between the electronic components in the second direction can now be determined by the lay-off position of the second transfer device and/or by displacing the product discharge carrier. A product discharge carrier is generally designated as a tray.

The device preferably comprises a transport system for displacing a product transport carrier from close to the first transfer device to a position close to the second transfer device. Displacement of the product transport carrier can thus also be mechanized in simple manner.

At least one additional module can be placed in the transport system for processing electronic components located on the product transport carrier. Here can be envisaged for instance a test device in which the electronic components are visually inspected or in which they are picked up so as to held against a test contact. Such an additional module can be fitted into the device according to the invention in very simple manner. Test devices have heretofore operated as separate units with an infeed station for trays and an outfeed station for trays. With integration of a test unit in the device according to the invention a number of operations are directly linked with each other and the test device can take a relatively simple form since separate infeed and outfeed means are no longer required. The flexibility of the device according to the invention is very great since one or more intermediate units can be fitted in and/or removed as desired in accordance with the changing requirement of the user.

The transport system is preferably a closed system so that the product transport carriers only circulate in the device.

In another preferred embodiment of the device the support for the product discharge carrier is formed by a table, which table is rotatable through at least 90°. The orientation of the product discharge carriers (trays) in which these are loaded with electronic components can thus be changed easily. This also contributes towards an increased flexibility of the device in the processing of trays and components of very diverse dimensions. The present invention will be further elucidated with reference to the non-limitative embodiments shown in the following figures. Herein:

Fig. 1 shows a perspective view of a device according to the invention, Fig. 2 shows a perspective detail view of the separator and transfer device which form part of the device shown in fig. 1, and

Fig. 3 shows a perspective detail view of the second transfer device likewise forming part of the device shown in fig. 1.

Fig. 1 shows a device 1 for separating electronic components 3 from a lead frame 2 and transferring electronic components 3 to a product discharge carrier or tray 6 using a first transfer device 4 and a second transfer device 5. The first transfer device 4 and second transfer device 5 will be discussed in more detail with reference to fig. 2 and 3. Lead frames 2 are supplied by a lead frame feed 7. After the electronic components 3 on a lead frame 2 have been removed, the remnants are removed along a discharge side 8 of lead frame feed 7.

The first transfer device 4 engages the electronic components 3 separated from a lead frame 2 and transfers them to a product transport carrier 9. Electronic components 3 are herein placed in rows 10 at adjustable mutual distance on the product transport carrier. The mutual distance between electronic components 3 in a row 10 cannot be altered using the first transfer device 4. The mutual distance between electronic components 3 in a row 10 corresponds with the mutual distance between electronic components 3 in this direction in lead frame 2.

The product transport carrier is located in a transport path 11 along which a filled product transport carrier 9 can be displaced to a position close to the second transfer device 5. After a product transport carrier 9 has been emptied by the second transfer device 5 it is carried back via a u-shaped return path 12 to a position where product transport carrier 9 can be loaded again using the first transfer device 4. Transport path 11 and u-shaped return path 12 thus form a closed circulation system for product transport carriers 9. As shown clearly in the figure, transport path 11 and u- shaped return path 12 are arranged on two tables 13,14. These tables 13,14 can be placed apart so that an extra module can be arranged between tables 13,14. Such a module can for instance be used to test electronic components 3 transported on product transport carriers 9. Other devices can of course also be interposed here as well as a test device.

Columns 15 of electronic components 3 on the product transport carrier 9 situated at the second transfer device 5 are engaged and transferred to a tray 6. The mutual distance between successively transferred columns 15 of electronic components 3 is herein controllable. Due to the transfer of electronic components 3 in two stages the mutual distance between electronic components 3 can thus be adjusted in two directions. Device 1 is therefore very widely applicable for electronic components 3 of varying dimensions and for lead frames 2 and trays of diverse dimensions. In order to further increase the flexibility of device 1 the tray 6 loaded by the second transfer device 5 is supported by a table 16 which is rotatable relative to a table frame 17. Trays 6 of diverse dimensions can thus be placed in different orientations for loading by the second transfer device 5. Further shown schematically on table 16 are tray holders 18 in which trays 6 can be stacked, for instance using a lift installation, and in which can be accommodated trays 6 loaded by the second transfer device 5 and in which can be accommodated empty trays 6.

Fig. 2 shows the first transfer device 4 to which lead frames 6 are supplied via lead frame feed 7. A position-holding member 22 is placed on a lead frame 7, whereafter the electronic components 3 are then engaged using suction nozzles 19' which are fixed in line to an arm 20' (both shown in dashed lines) of the first transfer device 4. Pushers 21 then move upward which urge electronic components 3 upward through position- holding member 22. Arm 20 of the first transfer device 4 subsequently moves further upward and will then rotate through roughly 180° so that it is situated above a product transport carrier 9. Recesses 23 can be arranged in product carrier 9 for holding precisely in position electronic components 3 placed on product transport carrier 9.

Using indexing wheels 24 the product transport carrier 9 is carried precisely into a position where a row of still empty openings 23 is positioned under arm 20. Once a row 10 of electronic components 3 has been placed on product transport carrier 9, the indexing wheels 24 will once again displace product transport carrier 9 so far that a following row of openings 23 is placed under the lay-off position of arm 20. Subject to the control of indexing wheels 24, product transport carriers 9 can be loaded with varying distances between the rows 10 in which electronic components 3 have to be placed. The mutual distance between the electronic components can thus be controlled in one direction by indexing wheels 24. It is of course possible to envisage alternatives to the indexing wheels 24, it thus being possible for instance to index with a mechanism which engages a product transport carrier from below. In an alternative embodiment the second transfer device 5 has a transfer arm 26 with a plurality of rows of suction nozzles 27 placed in line. A plurality of columns 15 of electronic components 3 can thus be engaged on product transport carrier 9. When arm 26 is then moved to the right, the engaged columns 15 of electronic components 3 will be placed one by one (i.e. column by column) on tray 6. In this alternative embodiment the arm 26 thus has to make fewer reciprocal movements between product transport carrier 9 and tray 6.

A remnant of a lead frame 7 from which all electronic components 3 have been removed can then be discharged.

Fig. 3 shows the second transfer device 5 provided with a transfer arm 26 in which are mounted suction nozzles 27 placed in a line. Using suction nozzles 27 a column 15 of electronic components 3 on product transport carrier 9 can be engaged. Arm 26 will subsequently move to the right along a linear guide 28 as according to arrow PI. Arm 26 must also be moved downward as according to arrow P2 in order to place the column 15 of engaged electronic components 3 on tray 6. The mutual distance between the columns 15 of electronic components 3 can be controlled subject to the control of arm 26. In an alternative embodiment the first transfer device 4 is provided with a plurality of arms 20. When two arms 20 are placed mutually parallel such as the shown arm 20 and the arm 20' shown in broken lines, it is possible when engaging a row 10 of electronic components 3 to simultaneously place a row 10 of electronic components 3 on product transport carrier 9 with another arm 20. When the first transfer device has for instance four arms 20, the positions located between engaging position and lay-off position can for instance also be utilized for visual inspection of electronic components 3 and/or for discharging rejected electronic components 3. In this latter case there will be no, or fewer, rejected electronic components 3 placed on product transport carrier 9. The mutual distance between electronic components 3 can thus also be adjusted in a second direction using device 1. Another aspect is that the quantity of electronic components 3 in a lead frame

2 does not have to correspond with the number of electronic components 3 fitting onto a product transport carrier 9, and that this number in turn does not have to correspond with the number of electronic components 3 for placing on a tray 6. When electronic components 3 have been removed from a product transport carrier 9, this latter will be displaced as according to arrows P3 along the u-shaped return path 12.

A filled tray 6 can be pushed as according to arrows P4 to a storage container 18 for filled trays 6.

The supply of empty trays 6 moves as according to arrow

P5 from a storage container 18 for empty trays 6.

*****

Claims

1. Method for separating electronic components, such as semi-conductors, from a lead frame and transferring the separated products to a product discharge carrier, wherein an electronic component separated from a lead frame is placed on a product transport carrier and subsequently transferred from the product transport carrier to the product discharge carrier.

2. Method as claimed in claim 1, comprising the steps of: a) supplying a lead frame to a separator and, once the electronic components have been removed therefrom, discharging the remnant of the lead frame, b) supplying a product transport carrier to a first transfer position, c) engaging at least one row of electronic components for separating in the lead frame, d) separating the engaged row of electronic components from the remaining part of the lead frame, e) transferring the engaged row of separated electronic components to the product transport carrier in a first transfer position, f) repeating the steps c,d,e and if necessary step a until the product transport carrier is filled, g) displacing the loaded product transport carrier to a second transfer position, h) engaging a column of electronic components on the product transport carrier, i) transferring the engaged column of electronic components to a product discharge carrier, j ) repeating the steps h and i until sufficient electronic components have been placed on the product discharge carrier or repeating the steps g,h,i as soon as the product transport carrier is emptied, and k) discharging the filled product discharge carrier.

3. Method as claimed in claim 1 or 2, wherein the electronic components are placed in a matrix pattern on the product discharge carrier.

4. Method as claimed in any of the foregoing claims, wherein the product transport carrier is driven during steps c-f with a stop-start movement.

5. Method as claimed in any of the foregoing claims, wherein at least one product transport carrier circulates in a closed transport system.

6. Method as claimed in any of the foregoing claims, wherein the electronic components placed in line on the product transport carrier by one transfer movement enclose a substantially perpendicular angle with the electronic components engaged in line on the product transport carrier by a second transfer movement.

7. Method as claimed in any of the foregoing claims, wherein a plurality of processing steps are performed at least partially simultaneously.

8. Device for separating electronic components, such as semi-conductors, from a lead frame and transferring the separated products to product discharge carriers, comprising:

- a separator for separating electronic components from a lead frame, - a first transfer device for engaging electronic components in the lead frame and displacing the separated electronic components,

- a support for a product discharge carrier close to the second transfer device, and

- drive means for driving separator, first and second transfer devices and displacing the product transport carrier.

9. Device as claimed in claim 8, wherein the device also comprises a supply system for supplying lead frames to the separator, which supply system is also provided with a discharge for lead frame remnants which are left behind after the electronic components have been removed by the separator and the first transfer device.

10. Device as claimed in claim 9, wherein the device comprises a transport system for displacing at least one product transport carrier provided with positioning means for positioned displacing of the product transport carrier with a stop-start movement during loading.

11. Device as claimed in any of the claims 8-10, wherein the first and second transfer device are provided with a number of engaging members for electronic components lying in line.

12. Device as claimed in claim 11, wherein the angle of the in-line engaging elements of the first transfer device relative to the product transport carrier during placing of electronic components lies substantially perpendicular to the angle of the in-line engaging elements of the second transfer device relative to the product transport carrier during engaging of the electronic components.

13. Device as claimed in any of the claims 8-12, wherein the device comprises a transport system for displacing a product transport carrier from close to the first transfer device to a position close to the second transfer device.

14. Device as claimed in claim 13, wherein at least one additional module is placed in the transport system for processing the electronic components located on the product transport carrier.

15. Device as claimed in claim 13 or 14, wherein the transport system is a closed system.

16. Device as claimed in any of the claims 8-15, wherein the support for the product discharge carrier is formed by a table, which table is rotatable through at least 90┬░.