Abstract: In an electronic circuit unit a concave portion housing a semiconductor component is provided on the rear surface of a circuit board and the disposed inside the concave portion in a state where the bottom portion of the semiconductor component is not protruded externally from the lower end of the concave portion. A different semiconductor component can be thermally compressed to the front surface side of the circuit board in a state where the lower end of the circuit board comes in contact with a jig and the circuit board is thus stably supported.

Abstract: A card connector assembly according to the present invention comprises a substrate on which wiring traces are formed and an electrical component is mounted, a plurality of contact lands connected to the respective wiring traces and arranged along an edge of the substrate, connecting traces that interconnect the respective contact lands and the respective wiring trace, and lands on the respective connecting traces, each land having a contact area for a test pin. Since test pins are in contact with the lands, no scratches are made on the contact lands. The commercial value of the card connector can thus be maintained.