Microelectronic packages in which at least one microelectronic device is arranged are well-known, and various types of such packages have been developed. Among other things, the packages serve for protecting the microelectronic device and allowing for easy electrical connection of the microelectronic device to another device. In general, dimensions of the packages are in the millimeter range. Examples of microelectronic devices are a processor chip, a MEMS microphone, wherein MEMS stands for Micro ElectroMechanical System, a transistor, a sensor die, a diod, a Light Emitting Diode (LED), etc.
In general, for the purpose of supporting the microelectronic device and for ensuring that the microelectronic package has a required robustness, a carrier substrate is provided, wherein the microelectronic device is attached to the substrate. In a usual embodiment of the microelectronic package, a side of the carrier substrate where the microelectronic device is present is covered with material, wherein the microelectronic device is encapsulated in this material, whereas another side of the carrier substrate is freely accessible.
The carrier substrate is provided with electrically conductive tracks extending from the one side of the substrate to the other side of the substrate, in order to allow for electric contact from outside of the package to the microelectronic device. It is possible to have the electrically conductive tracks when a printed circuit board is provided, but in many cases, a metal lead frame, for example a copper lead frame, is provided for realizing these tracks. Such a lead frame is manufactured by providing a metal sheet, removing portions from this sheet and possibly bending this sheet in order to obtain a desired appearance of the lead frame. In practical cases, approximately ten times the sheet surface needed for forming the lead frame is thrown away when the lead frame is manufactured in this way.