Field of the Invention

The present invention relates to a package for components of a circuit carrier, in general, and in particular for storing said components and providing supply of said components in an automated pick-and-place manufacturing process of Application Specific Integrated Circuits.

Background of the Invention Known methods and devices for automated placement of components on a circuit substrate use electronic image recognition techniques for recognising an individual component, to determine its location and orientation and to guide a manipulating device to the location of the circuit component and to pick it. One of the problems in the automated manipulation of elements is the correct recognition of their orientation. In general it is not difficult to automatically recognize the body of a component if the background's brightness differs sufficiently from that of the body of the component. Since the body of the component usually has no features from which the orientation of the component might be concluded the orientation of the component is recognisable from the shape of its contacts. One of said contact conventionally has a pointed end and the other one has a swallowtail-shaped one. The contacts are recognizable in an automated process if the component is placed on a dark, highly contrast background.

If the elements are provided in a package and their orientation in the package varies, the recognition of their orientation still can be carried out, but the process of picking and placing the component requires additional manipulation of the component in order to have it placed correctly. This problem is especially acute in case of so called beamlead components. These are semiconductor components having a very small chip size of typically about 100 to 400 μm edge length, which carry laterally protruding flat metallic connecting or soldering vanes for making contacts. These components are difficult to manipulate due to their small size, the brittleness of the semiconductor material and the sensitivity of the connection vane. However, in some

high frequency applications they are indispensable because they achieve extremely low parasitic capacities and, hence, high switching speeds. Within microwave hybrid modules at microwave and especially at millimeter- wave frequencies the application of beamlead devices cannot be avoided. Key advantages are extremely small terminal inductances compared with standard chip devices. Possible alternatives are in some cases flip-chip elements but they are not available for all semiconductor types depending on wafer processes. Typical example of such beamlead devices, which cannot be replaced by flip-chip elements are step recovery diodes.

Usually beamlead devices are packaged using a gel-pack or a waffle-pack.

Delivered waffle packs have pockets of arbitrary size with more or less good matching to the component's size. Result is that the components are delivered like bulk material.

A waffle -pack is an injection moulded plastic package, which contains pockets to store a component. The pocket size is normally chosen depending on the size of the component to be packaged. For micro-devices as beamlead diodes, the available pocket sizes do not fit exactly the X, Y and Z dimensions and the diodes are provided more or less as bulk material in a standard waffle-pack, as illustrated on FIG. 1. Due to technological constraints attempts to manufacture of moulded-plastic packages in the form of waffle -pack with the pockets' sizes corresponding to the sizes of the beamlead devices were unsuccessful. The package is closed by an injection-moulded lid. If the components are placed on the walls between the pockets of the package (like the semiconductor device 106 of FIG. 1 illustrating the prior art), they can be damaged by the lid, which is usually pressed onto the injection-moulded part containing the pockets. Quality issues are necessarily the result of this. The suppliers try to avoid this effect by use of several paper sheets or plastic foils to fill-up a potential gap between package and lid. This is more or less successful due to limited dimensional tolerances and distortion of injection-moulded parts. Small devices like beamlead diodes are less than lOOμm thick. They easily adhere to these papers during lid removal or travel out of the pockets, which is illustrated on FIG. 1. The chaotically scattered beamlead elements cause the problems already discussed: need for additional manipulation to get them placed

correctly, the quality issues caused by the fact that some of the elements can be damaged during closing the package with the lid.

The gel-pack packages due to their nature limit the beamlead attach to manual procedures or requires re-packaging. Re-packaging is extremely time-consuming. During manual re-packaging a relatively high amount of devices can be damaged mechanically and have to be replaced after attachment. Failures, which pass the assembly process, are detected almost too late during electrical test. Result is costly and time-consuming repair work.

Hence, an improved package for beamlead components would be advantageous and in particular one that allows for elimination of the re-packaging step in the pick- and-place assembly process.

Summary of the Invention

Accordingly, the invention seeks to preferably mitigate, alleviate or eliminate one or more of the disadvantages mentioned above singly or in any combination.

According to the present invention there is provided a package for storing and providing supply of beamlead semiconductor devices in a pick-and-place manufacturing process of Application Specific Integrated Circuits (ASICs). The beamlead semiconductor devices in the manufacturing process are picked directly from said package. Said package comprises a container part and a lid part, said container part comprising plurality of regularly displaced, substantially flat-bottom recesses and said lid part being detachably attached to said container part. At least a top surface of said container part is made of electric conductive material and said top surface of said container is covered with a non-reflective coating and the lid part is transparent in at least these areas, which are located above the recesses.

Further features of the present invention are as claimed in the dependent claims.

The present invention beneficially allows for using the same package for storing, transport and supplying the beamlead semiconductor devices without the need of repackaging. With the beamlead devices all placed in the recesses and oriented in the same direction it is possible to reduce the number of manipulation that the pick-and- place robot has to do, which results in shortening the assembly time. Beamlead devices placed in the recesses are well protected against accidental mechanical damages and the metal used for the container part prevents static electric charges to be accumulated on the package. Use of transparent material for the lid allows for carrying visual inspection of the beamlead semiconductor devices before assembly. All these allows for using in the assembly process the elements that are free from defects, which significantly reduces the repair costs.

Brief description of the drawings

The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

FIG. 1 is a diagram illustrating a package for beamlead devices known in the prior art;

FIG. 2 is a diagram illustrating a package for beamlead devices with one embodiment of the present invention;

FIG. 3 is a diagram illustrating cross-section of a package for beamlead devices with one embodiment of the present invention;

FIG.4 is a diagram illustrating cross-section of a package for beamlead devices with one embodiment of the present invention.

Description of an embodiment of the invention With reference to FIG. 2 and FIG. 3 a package 200 for storing and providing supply of beamlead semiconductor devices 202, 204, 206 is shown. The package 200 is

very useful in a pick-and-place manufacturing process of Application Specific Integrated Circuits (ASICs). As the production of ASICs is very complicated and due to cleanliness regime and small sizes of the semiconductor devices used in assembly of the ASICs it is important to have the semiconductor devices 202, 204, 206 supplied in a way that ensures highest quality standards and by minimizing risk of faulty component being placed on a circuit substrate. The package 200 comprises a container part 302 and a lid part 304. By having the lid 304 that closely adhere to the container 302 the semiconductor devices 202, 204, 206 are prevented from traveling out of their recesses. If the semiconductor devices stay in their recesses the risk of mechanical damage during closing the container and/or re-packaging is eliminated. The container part 302 comprises plurality of regularly displaced, flat-bottom recesses.

In one embodiment the top view of each of the recesses is rectangular and this prevents the semiconductor devices 202, 204, 206 from rotating and in this way it preserves the original orientation of the devices 202, 204, 206. This, in turn, helps to minimize the number of operation (moves) necessary to perform by the pick-and-place robot in the process of placing the semiconductor device on the circuit substrate.

In an alternative embodiment the shape of the top view of the recesses is oval.

The lid 304 is detachably attached to the container part 302 and is transparent in at least these areas, which are located above the recesses. The transparent lid allows for optical inspection of the semiconductor devices before start of assembling the ASIC and without the need of opening the package.

In one embodiment the container part is made of metal. Using metal as a material for the container has several advantages. One of this is that metal is very durable and once the container is formed it may be re-used for a long period of time. The best results in manufacturing the container part 302 are achieved when the recesses are formed in a process of stamping. As metal is easy to stamp using it for the container part is a good choice. The other advantage of using metal for the container is fact that it

is easy to discharge static electric charges that may be dangerous for the semiconductor devices stored in the package.

In an alternative embodiment, as depicted on FIG. 4, the container part 302 is made of two layers: a bottom layer 402 and a top layer 404. In this embodiment the bottom layer 402 is made of plastic and the top layer 404 is made of metal.

As the semiconductor devices are picked by the pick-and-place robot and recognition of the semiconductor devices is carried out by an optical system and image recognition technique the top surface 400 of said container part 302 is covered with a non-reflective coating that also ensures high contrast with the semiconductor devices. In one embodiment the high contrast coating is achieved by black anodising, but alternative types of coating are also possible.

The dimensions of the recesses depend on the types of the semiconductor devices and are in the range of 100 to 400 μm. However, smaller and bigger that that recesses are also possible.