I'm looking at high volume manufacturing and I notice that inside some consumer toys, there are chips which seem to be directly placed on the board and covered in resin. I know this has been done a long time because I remember such boards from my childhood in pocket calculators. See the image for a typical example.
What is under this resin? Is it a naked chip directly mounted on the board with bond wires to the pcb?
Can someone enlighten me to the name and type of manufacturing process here and tell me anything about how hard it is to use this approach, in terms of working with a manufacturer, and the costs and volumes involved, relative to just using a regular surface mount chip?