A semiconductor package substrate includes a composite and stacked vertical interconnect on a land side of the substrate. The composite and stacked vertical interconnect includes a smaller contact end against the semiconductor package substrate, and a larger contact end for board mounting.

A soldering device includes a detection sensor which can detect a liquid level height of molten solder inside a solder bath. It is determined whether or not a detection height which is the detected liquid level height is greater than or equal to a first set height which is arbitrarily set. In a case where the detection height is greater than or equal to the first set height, it is estimated that the amount of molten solder capable of performing a soldering work for a predetermined number or more of boards is stored in the solder bath. The amount of molten solder stored in the solder bath is estimated by multiplying a difference between a detection height which is the detected liquid level height of the molten solder and a second set height which is preset, by an area inside the solder bath in a horizontal direction.

An interconnection includes a cable assembly and a board assembly. The cable assembly includes a cable having an inner conductor. The board assembly comprises an intermediate layer disposed between first and second outer layers, a recess disposed between the first and second outer layers so as to form a cable-receiving space at a first side edge, and a first inner-conductor contact opening extending through at least one of the first and second outer layers and opening into the cable-receiving space. The inner conductor is inserted at the first side edge into the cable-receiving space and is disposed at an offset in a longitudinal direction relative to the first inner-conductor contact opening. The inner conductor is electrically conductively soldered via a first soldered inner-conductor connection to a first inner-conductor connection region of the first and/or second outer layers, at least in a region of the first inner-conductor contact opening.

A soldering device includes a detection sensor which can detect a liquid level height of molten solder inside a solder bath. It is determined whether or not a detection height which is the detected liquid level height is greater than or equal to a first set height which is arbitrarily set. In a case where the detection height is greater than or equal to the first set height, it is estimated that the amount of molten solder capable of performing a soldering work for a predetermined number or more of boards is stored in the solder bath. The amount of molten solder stored in the solder bath is estimated by multiplying a difference between a detection height which is the detected liquid level height of the molten solder and a second set height which is preset, by an area inside the solder bath in a horizontal direction.

An embodiment composite material for semiconductor package mount applications may include a first component including a tin-silver-copper alloy and a second component including a tin-bismuth alloy or a tin-indium alloy. The composite material may form a reflowed bonding material having a room temperature tensile strength in a range from 80 MPa to 100 MPa when subjected to a reflow process. The reflowed bonding material may include a weight fraction of bismuth that is in a range from approximately 4% to approximately 15%. The reflowed bonding material may an alloy that is solid solution strengthened by a presence of bismuth or indium that is dissolved within the reflowed bonding material or a solid solution phase that includes a minor component of bismuth dissolved within a major component of tin. In some embodiments, the reflowed bonding material may include intermetallic compounds formed as precipitates such as Ag.sub.3Sn and/or Cu.sub.6Sn.sub.5.

A soldering apparatus, that moves a jet nozzle while ensuring that molten solder does not spill to the outside of the jet nozzle, is provided. The soldering apparatus includes a solder tank storing the molten solder, a jetting mechanism including the jet nozzle and a pump, which pumps the molten solder stored in the solder tank, an XY-direction moving mechanism that moves the solder tank, and a control device that controls the acceleration and deceleration of the solder tank according to the height of the molten solder protruding upwards from a tip of the jet nozzle or the height of the molten solder protruding upwards from the tip of the jet nozzle according to the acceleration and deceleration of the solder tank.

A thermocompression bonding system for bonding semiconductor elements is provided. The thermocompression bonding system includes (1) a bond head assembly including a heater for heating an semiconductor element to be bonded, the bond head assembly including a fluid path configured to receive a cooling fluid; (2) a pressurized cooling fluid source; (3) a booster pump for receiving a pressurized cooling fluid from the pressurized cooling fluid source, and for increasing a pressure of the received pressurized cooling fluid; (4) a pressurized fluid reservoir for receiving pressurized cooling fluid from the booster pump; and (5) a control valve for controlling a supply of pressurized cooling fluid from the pressurized fluid reservoir to the fluid path.

A thermocompression bonding system for bonding semiconductor elements is provided. The thermocompression bonding system includes (1) a bond head assembly including a heater for heating an semiconductor element to be bonded, the bond head assembly including a fluid path configured to receive a cooling fluid; (2) a pressurized cooling fluid source; (3) a booster pump for receiving a pressurized cooling fluid from the pressurized cooling fluid source, and for increasing a pressure of the received pressurized cooling fluid; (4) a pressurized fluid reservoir for receiving pressurized cooling fluid from the booster pump; and (5) a control valve for controlling a supply of pressurized cooling fluid from the pressurized fluid reservoir to the fluid path.

A thermocompression bonding system for bonding semiconductor elements is provided. The thermocompression bonding system includes (1) a bond head assembly including a heater for heating an semiconductor element to be bonded, the bond head assembly including a fluid path configured to receive a cooling fluid; (2) a pressurized cooling fluid source; (3) a booster pump for receiving a pressurized cooling fluid from the pressurized cooling fluid source, and for increasing a pressure of the received pressurized cooling fluid; (4) a pressurized fluid reservoir for receiving pressurized cooling fluid from the booster pump; and (5) a control valve for controlling a supply of pressurized cooling fluid from the pressurized fluid reservoir to the fluid path.