A method of manufacturing an electronic module includes supplying paste to an electronic component and/or a wiring board. The paste includes solder powder and first resin. The method includes supplying second resin to the electronic component and/or the wiring board. The method includes placing one of the electronic component and the wiring board on another. The method includes curing the second resin to form a second resin portion. The method includes heating the paste to a temperature equal to or higher than a solder melting point after the second resin portion is formed. The method includes solidifying molten solder at a temperature lower than the solder melting point to form a solder portion that bonds the electronic component and the wiring board. The method includes curing the first resin after the solder portion is formed, to form a first resin portion.

A resin flux solder paste includes a solder powder, and a flux, in which the flux contains at least an epoxy resin, a curing agent, a curing accelerator, and an activator, the epoxy resin contains 10% to 90% by weight of one or more of a biphenyl aralkyl type epoxy resin, a naphthalene type epoxy resin, and a dicyclopentadiene type epoxy resin, having an epoxy equivalent of 200 to 400, with respect to a total amount of the epoxy resin, and the curing agent contains 30% to 95% by weight of a biphenyl aralkyl phenol resin having a hydroxyl group equivalent of 150 to 350 with respect to a total amount of the curing agent, and 5% to 70% by weight of a phenol novolac resin having an allyl group having a hydroxyl group equivalent of 100 to 200 with respect to the total amount of the curing agent.

A resin flux solder paste includes a solder powder, and a flux, in which the flux contains at least an epoxy resin, a curing agent, a curing accelerator, and an activator, the epoxy resin contains 10% to 90% by weight of one or more of a biphenyl aralkyl type epoxy resin, a naphthalene type epoxy resin, and a dicyclopentadiene type epoxy resin, having an epoxy equivalent of 200 to 400, with respect to a total amount of the epoxy resin, and the curing agent contains 30% to 95% by weight of a biphenyl aralkyl phenol resin having a hydroxyl group equivalent of 150 to 350 with respect to a total amount of the curing agent, and 5% to 70% by weight of a phenol novolac resin having an allyl group having a hydroxyl group equivalent of 100 to 200 with respect to the total amount of the curing agent.

A method of manufacturing an electronic module includes supplying paste to an electronic component and/or a wiring board. The paste includes solder powder and first resin. The method includes supplying second resin to the electronic component and/or the wiring board. The method includes placing one of the electronic component and the wiring board on another. The method includes curing the second resin to form a second resin portion. The method includes heating the paste to a temperature equal to or higher than a solder melting point after the second resin portion is formed. The method includes solidifying molten solder at a temperature lower than the solder melting point to form a solder portion that bonds the electronic component and the wiring board. The method includes curing the first resin after the solder portion is formed, to form a first resin portion.

The disclosure describes techniques for eliminating or reducing non-wet open (NWO) defect formation by using a low activity flux to prevent a solder paste from sticking to ball grid array (BGA) solder balls during reflow soldering. The low activity flux may be configured such that: i) it creates a barrier that prevents the solder paste from sticking to the solder balls of the BGA; and ii) it does not impede the formation of solder joints during reflow. In implementations, a solid coating of the low activity flux may be formed over balls of the BGA, and the BGA may then be bonded to a PCB during reflow. In implementations, the balls of a BGA may be dipped in a low-activity creamy or liquid flux prior to reflow. In some implementations, the flux may applied on a solder paste printed on pads of the PCB, followed by placement of a BGA.

The disclosure describes techniques for eliminating or reducing non-wet open (NWO) defect formation by using a low activity flux to prevent a solder paste from sticking to ball grid array (BGA) solder balls during reflow soldering. The low activity flux may be configured such that: i) it creates a barrier that prevents the solder paste from sticking to the solder balls of the BGA; and ii) it does not impede the formation of solder joints during reflow. In implementations, a solid coating of the low activity flux may be formed over balls of the BGA, and the BGA may then be bonded to a PCB during reflow. In implementations, the balls of a BGA may be dipped in a low-activity creamy or liquid flux prior to reflow. In some implementations, the flux may applied on a solder paste printed on pads of the PCB, followed by placement of a BGA.

Provided is a non-electroconductive flux capable of enhancing productivity and impact resistance of a connected structure to be obtained and suppressing occurrence of solder flash. The non-electroconductive flux according to the present invention contains an epoxy compound, an acid anhydride curing agent, and an organophosphorus compound.

A flux transfer tool includes a heater, a flux supplier, an ejector and a baseplate. The heater has a nozzle. The flux supplier is connected to the heater and contains a flux. The ejector is connected to the heater. The baseplate has a plurality of first holes formed thereon. The flux supplier supplies the flux to the heater, the heater heats the flux, and the ejector ejects the flux from the nozzle to spray the flux on the baseplate.

In an embodiment a carrier structure includes at least one conductor structure configured for electrically contacting electrical components, wherein the conductor structure includes a plurality of conductor bodies, wherein at least some of the conductor bodies are in direct contact with electrically conductive first connectors, and wherein the conductor structure includes the conductor bodies and the first connectors.

Provided is a non-electroconductive flux capable of enhancing productivity and impact resistance of a connected structure to be obtained and suppressing occurrence of solder flash. The non-electroconductive flux according to the present invention contains an epoxy compound, an acid anhydride curing agent, and an organophosphorus compound.