includes controlling viscosity of a sealing resin with ultrasonic vibration so that the first bump electrode penetrates the sealing resin and using the ultrasonic vibration to electrically connect the first bump electrode to the second bump electrode when at least one of the semiconductor chip and the wiring board has the second bump electrode or using the ultrasonic vibration to electrically connect the first bump electrode to the connection electrode when at least one of the semiconductor chip and the wiring board has the connection electrode application_number US 84347804 A description embodiments of the invention will hereinafter be described in reference to the drawings in the following embodiment a process of collective connection and resin sealing is performed by use of ultrasonic vibration under a condition at 100 u00b0 c a sealing resin is softened so that a bump completely penetrates the sealing resin and then the bump is brought into contact with and bonded to a pad formed on a wiring board in order to maintain the bonding temperature and resin sealing temperature the sealing resin is adequately fused and a temperature at which viscosity thereof is the lowest is selected this makes it possible for the bump to penetrate the sealing resin fig5 is a diagram showing temperature dependency of the resin viscosity before hardening of the sealing resin made of epoxy resin or the like which is a thermosetting resin the vertical axis of the diagram indicates the resin viscosity pa u00b7 s and the horizontal axis of the diagram indicates resin temperature temp u00b0 c temperature curves a to e of.