TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The edge of the body of the substrate pad comprises at least two edges of the body of the substrate pad shaped to conform to at least two corresponding edges of the component pad, where: two edges of the body of the substrate pad comprise at least two opposite edges; a distance between the opposite edges of the body of the substrate pad is equal to a distance between corresponding edges of the component pad; and there are pad fingers on the two opposite edges of the body of the substrate pad, or on the three edges of the body of the substrate pad. The substrate pad area and shape within the body of the substrate pad is equal in area and shape to the component pad, where: a width of the pad fingers is smaller than a width of a space between two pad fingers; and a sum of widths of the pad fingers along an edge of the substrate pad is smaller than half of a length of the same edge of the body of the substrate pad. The substrate pad has room for solder fillets on the pad fingers. The body of the substrate pad is a rectangle or a polygon. The component pad shape is oval, where: the edges of the body of the substrate pad are shaped to conform to corresponding edges of the oval component pad; and the edges of the body of the substrate pad further comprise pad fingers leading away from the oval substrate pad. The first component comprises: a solar cell receiver; a solar cell; or a mounting frame for a secondary optical component. The first component has at least one first component substrate pad on it, where: at least two opposite edges of a body of the first component substrate pad are shaped to conform to corresponding edges of a second component pad on a second component; a distance between the opposite edges of the body of the first component substrate pad is equal to a distance between the corresponding edges of the second component pad; and the opposite edges of the body of the first component substrate pad further comprise the pad fingers leading away from the first component pad. Preferred Method: The step (b) comprises providing solder paste on the substrate pad or the component pad to cover the substrate pad and the component pad up to a distance of 2-20 mils from an edge of the body of the substrate pad and an edge of the component pad, where the solder paste is provided: for solder after melting to cover the body of the substrate pad in a thickness of at least 1 mil, and to build solder fillets on the pad fingers; and to prevent solder bridging between pad fingers. In the method (M1), many substrate pads are provided and many component pads are soldered to the substrate pads. The method (M2) further comprises soldering the second component to the first component substrate pad, where the second component comprises: the secondary optical component; or the solar cell or the mounting frame.