Abstract: Determination of the quality of blind solder interconnections by X-ray inspection is made possible by forming indicator features on the pads of a component and the pads of the surface on which the component is to be mounted. The indicator features consist of an area which is different in size and/or shape than that of the other pad to be joined. For example, the indicator feature may be a circular region with an area approximately twice that of the pad to which it is to be joined. A relatively large amount of solder is deposited on the smaller pad and the two pads are placed in contact. During reflow, the molten solder on the smaller pad will flow to cover the full area of the indicator feature, indicating that a good interconnection was obtained. The indicator features may also be a different shape from that of the pad to which it is to be joined so that the solder deposited on the pad will take on the shape of the indicator feature when successful interconnection is achieved.