Device and method for processing electronic components with a double cutting flow

The present invention relates to a device for processing an assembly of electronic components with a cutting flow. The present invention also relates to a method for processing an assembly of electronic components with a cutting flow.

Electronic components usually have to be processed such that they obtain the desired dimensions to be suitable for further processing. During the production of electronic components, a plurality of electronic components are typically connected to a shared substrate, such as for instance a lead frame, and are separated from each other after undergoing one or more processes. Specific processes can thus be carried out relatively effectively. Examples of such processes are: wire bonding, testing, encapsulation and so forth. A separation process, wherein a plurality of mutually connected electronic components are detached from each other, traditionally takes place by means of punching and/or sawing operations. According to recent developments it is however also possible to realize such a separation by means of a cutting flow with a high energy density, wherein the individual electronic components are cut loose from each other using a cutting flow. Examples of such cutting flows are, among others, (abrasive) water jets and laser beams. Although separation using cutting flows has a number of important advantages, such as, among others, a high precision whereby very small products (for instance smaller than 3x3 mm) can also be separated, the maximum available processing capacity of separating equipment operating using cutting flows has heretofore been limited. Another advantage of cutting flows is the great freedom of shape with which products can be cut.

The present invention has for its object to provide a device and method with which the processing capacity for processing an assembly of electronic components with a cutting flow can be increased considerably while retaining the prior art advantages.

The present invention provides for this purpose a device for processing an assembly of electronic components with at least a double cutting flow, comprising: a power source for generating at least two cutting flows, a double cutter head connecting to the power source for directing the double cutting flow at the assembly for processing, a carrier for

holding the assembly of electronic components, and drive means for mutually displacing the double cutter head and the carrier, wherein the mutual distance between the flows coming from the double cutter head is adjustable in a direction perpendicular to the cutting direction. Because the distance between two cutting flows integrated into the same cutter head in such a device is adjustable in the direction perpendicular to the mutual direction of displacement of the cutter head and the carrier, it becomes possible to also vary the operating distance between cutting flows lying very close together. This provides the option of for instance utilizing a jointly controllable double cutting flow between two electronic components such that two sides of electronic components lying adjacently in the assembly can be processed simultaneously, wherein the distance between the two cuts that are close together can be regulated subject to the conditions. This provides the possibility of processing products of varying dimensions effectively (with a double cutter head) and of compensating possible change in the mutual distance between two assembled cutting flows (for instance as a result of wear of the double cutter head). It is noted that it is already possible according to the prior art to process an assembly of electronic components with two (or more than two) cutting flows simultaneously, but that such cutting flows must necessarily be located some distance from each other (at least in the order of magnitude of centimetres) because the size of the cutter heads prevents the possibility of the cutting flows being placed at a very short distance from each other (in the order of magnitude of millimetres or less). By means of the present invention, wherein a double cutting flow comes from a single cutter head, the cutter head being provided with two flow outlet openings rigidly connected to each other, there is no longer any limitation in respect of the minimal mutual distance between the cutting flows. This results in an increased efficiency of the device according to the invention compared to the existing separating equipment.

It is furthermore noted that the double cutting flow can also consist of a single non- round cutting flow or two (or even more than two) mutually connecting or partly overlapping cutting flows. The width of the combined cutting flow can then be set in a direction perpendicular to the cutting direction by rotation.

The device can be embodied such that the flow nozzle has a freedom of rotation relative to the carrier. By simply placing a product for processing in a desired rotational position the distance between two rigidly assembled flow openings can thus be determined in the

direction perpendicular to the mutual direction of displacement of the cutter head and the carrier. This is therefore a very simple way of regulating the operating distance between the cutting flows coming from the same cutter head. Another possibility of regulating the operating distance between the cutting flows coming from the same cutter head can be obtained if the carrier has a freedom of rotation relative to the cutter head. This is a kinematic reversal of the above described rotatable double cutter head. The rotatable double cutter head nevertheless has the advantage relative to a rotatable carrier that it is also possible to utilize a plurality of rotatable cutter heads simultaneously, wherein the adjustability of the relative operating distance of cutting flows coming from a single cutter head can be retained; this is not possible with only a rotatable carrier. A device taking a multiple form is provided with a plurality of double cutter heads connecting to the power source, each head adapted to direct a double cutting flow at the assembly for processing.

For a simple rotatability thereof, a cutter head can be provided with a rotatable cylindrical housing.

The power source can be formed by a laser source which is adapted to generate a double laser beam. Cutting is thus realized using a double laser beam. The invention is particularly advantageous however if the power source is a pump for generating a double medium flow, preferably a jet of liquid. In liquid cutting (usually with water jets) it is less possible to generate two flows of liquid a short distance from each other, other than when they come from a double cutter head. The invention is therefore most advantageous particularly in such applications.

The present invention also provides a method for processing an assembly of electronic components with at least a double cutting flow, comprising the processing steps of: A) positioning an assembly of electronic components for processing on a carrier relative to a double cutter head, B) rotating the assembly of electronic components relative to the cutter head for processing in a direction perpendicular to the flow direction such that the mutual distance between the flows coming from the double cutter head has a desired length in a direction perpendicular to the cutting direction, and C) mutually displacing the double cutting flow coming from the cutter head and the assembly of electronic components placed on the carrier such that the cutting operation is performed on the

assembly. The double cutter head can herein be rotated relative to a non-rotating carrier during processing step C) and/or the carrier can be rotated relative to a non-rotating cutter head during processing step C). As already described above, the assembly of electronic components can also be processed simultaneously by a plurality of double cutting flows, at least if the cutter heads are rotatable. For a further description of the advantages of the method according to the present invention reference is made to the above described advantages of the device according to the invention.

The present invention will be further elucidated on the basis of the non-limitative exemplary embodiments shown in the following figures. Herein: figure 1 shows a perspective view of an assembly of encapsulated electronic components partly divided by means of cutting operations, figure 2 shows a top view of a part of an assembly of electronic components divided into separate segments, figure 3 shows a schematic view of a device according to the present invention, figure 4A shows a perspective view of a double cutter head for generating a double cutting flow, figure 4B show a top view of the double cutter head of figure 4A during processing of an assembly of electronic components.

Figure 1 shows an assembly of electronic components 1 consisting of a lead frame 2 on which a number of housings 3 are arranged. Housings 3 shield the electronic components located therein and therefore not visible as such. The individual electronic components shielded by a housing 3 must be released separately from assembly 1. This is initiated by arranging cuts 4 which pass through both housing 3 and lead frame 2.

As shown in figure 2, the electronic components 10 for separating do not usually connect fully onto each other; this is because there is an intermediate part 11 situated between adjacent components, which is discarded as waste after separation of components 10. Two parallel cuts 12, 13 are thus always arranged between two adjacent components 10. The advantage that the present invention provides is that such parallel cuts 12, 13 between two adjacent components 10 (i.e. cuts 12, 13 are usually a very short distance from each other) can be arranged simultaneously in a single processing run, and that the mutual distance between cuts 12, 13 is nevertheless adjustable.

Figure 3 shows a schematic view of a separating device 20 according to the invention with a double cutter head 21 which is connected to a power source 22 for generating two cutting flows 23. Cutting flows 23 process an assembly of electronic components 25 lying on a carrier 24. Carrier 24 is translatable in directions X and Y to thus enable movement of assembly 25 under cutter head 21. The mutual operating distance D of the two cutting flows 23 can now be adjusted by rotating the cutter head in a rotation direction Rl. This will be further elucidated with reference to figure 4B.

Figure 4A is a perspective view of a cylindrically embodied cutter head 30 provided with two flow openings 31, 32 placed rigidly relative to each other. Figure 4B shows cutter head 30 in top view. Two cuts 34, 35 are arranged in an assembly of electronic components 33 by cutter head 30. The assembly of electronic components 33 is moved for this purpose in a direction Pl relative to cutter head 30. The mutual distance between cuts 31, 32 can be influenced by now rotating cutter head 30 (as according to arrow R2). The remaining material 36 between cuts 34, 35 is waste.