A printed wiring board includes an insulating layer, a conductor layer formed on the insulating layer and including first and second pads, a solder resist layer formed on the insulating layer, covering the conductor layer and exposing the first and second pads to form the second pad having diameter smaller than diameter of the first pad, a first bump formed on the first pad and including first base and top plating layers such that the first base layer has embedded portion in the resist layer and exposed portion and having diameter substantially equal to or smaller than diameter of the embedded portion, and a second bump formed on the second pad and including second base and top plating layers such that the second base layer has embedded portion in the resist layer and exposed portion and having diameter substantially equal to or smaller than diameter of the embedded portion.

Provided is a method for removing an electronic socket from a printed wiring board. The method comprises placing an embrittlement sheet over an electronic socket on a printed wiring board. The electronic socket is mounted to the printed wiring board using a plurality of hidden solder joints. The method further comprises causing the embrittlement sheet to melt. The melted embrittlement sheet wets the plurality of hidden solder joints. The electronic socket is removed from the printed wiring board by breaking the embrittled solder joints.

Provided is a method for removing an electronic component from a printed wiring board. The method comprises applying an embrittlement agent to a lead of an electronic component that is soldered to the printed wiring board. The electronic component is removed from the printed wiring board by breaking the embrittled lead.

Provided is a system for removing an electronic component from a printed circuit board (PCB). The system may comprise a heating well configured to hold a rework liquid. The system may further comprise a head system configured to create a liquid-tight seal around an electronic component. The system may further comprise a nozzle and a mechanical capture device disposed within the head system. The mechanical capture device may be configured to attach to the electronic component. The system may further comprise a controller. The controller may be configured to release the rework liquid through the nozzle and onto the electronic component and lift the electronic component off the PCB.

Systems and methods for applying solder to a pin. The methods comprising: disposing a given amount of solder on a non-wetable surface of a planar substrate; aligning the pin with the solder disposed on the non-wetable surface of the planar substrate; inserting the pin in the solder; and performing a reflow process to cause the solder to transfer from the planar substrate to the pin.

An assembling method of an electronic module is disclosed and includes steps of: (a) providing a first circuit board including a first side and a second side; (b) providing a second circuit board including a third side and a fourth side, and a connection component connected to the third side; (c) providing a solder ball, and stacking the first circuit board, the second circuit board and the solder ball; and (d) performing a reflow soldering process to a stacked structure of the first circuit board, the second circuit board and the solder ball.

A method for producing a sandwich arrangement consisting of a first component having a contact surface A, a second component having a contact surface D and a solder located between said contact surfaces A and D,

wherein the solder is produced by melting a solder deposit that is arranged between the two components and connected at the contact surface A or D to one of the components, followed by cooling of the molten solder to below its solidification temperature,
wherein the solder deposit is produced previously by melting a solder preform that is fixed to the relevant contact surface A or D by means of an applied fixing agent from a fixing agent composition, followed by cooling of the molten solder to below its solidification temperature, and
wherein the solder deposit is arranged with its free contact surface facing the corresponding contact surface D or A of the as of yet unconnected component, wherein the fixing agent composition consists of
0 to 97 wt. % (weight %) of at least one solvent selected from the group consisting of water and organic solvents boiling at 285 C.,
3 to 100 wt. % of at least one M1 material selected from the group consisting of (i) thermoplastic organic polymers that are meltable between 30 and 180 C. and (ii) non-polymeric organic compounds with no acidic groups that are meltable between 30 and 180 C.,
0 to 20 wt. % of at least one M2 material selected from the group consisting of (iii) organic polymers that are not meltable between 30 and 180 C. and (iv) non-polymeric organic compounds with no acidic groups that are not meltable between 30 and 180 C. and not having a boiling point or having a boiling point above 285 C., and
0 to 30 wt. % of one or more inorganic solid fillers, and
wherein the sum of the surface sections that are provided with the fixing agent, of the contact surfaces A and B or C and D that upon placing the solder preform together form a common overlapping area, in the presence of one or more components (i) in the at least one M1 material is 1500 m.sup.2 to 50 area % of the common overlapping area, while, when only one or more of the components (ii) are present in the at least one M1 material said sum is 1500 m.sup.2 to 100 area % of the common overlapping area.

The invention relates to a method (S) for attaching an SMD to a printed circuit (10), comprising the following steps: applying an insulating layer (20) (S1) onto the printed circuit (10), forming a cavity (22) in the insulating layer (20) above the conductive layer (12) (S2) of the printed circuit, filling the cavity (22) with a solder paste (3), positioning the SMD over the cavity (22) (S4), and applying a heat treatment (S5) to the printed circuit (10).

A method for repairing a through-hole includes inserting a repair coil, comprising a tightly-wound repair strip, into a through-hole and inserting a heating element into the repair coil. Passing an electrical current through the heating element liquefies a bonding material disposed on the repair coil and the repair coil expands within the through-hole. Subsequently solidifying the bonding material bonds the repair coil to the through-hole. A repair assembly comprises a repair coil inserted into a through-hole and a heating element inserted into the repair coil. The repair coil comprises a tightly-wound repair strip. The heating element comprises a segment of a heating wire enclosed within an insulating material. Passing an electric current through the segment of the heating wire liquefies bonding material disposed on the repair coil and the repair coil expands within the through-hole. The liquified bonding material solidifies to bond the repair coil to the through-hole.

A printed wiring board includes an insulating layer, a conductor layer formed on the insulating layer and including first and second pads, a solder resist layer formed on the insulating layer, covering the conductor layer and exposing the first and second pads to form the second pad having diameter smaller than diameter of the first pad, a first bump formed on the first pad and including first base and top plating layers such that the first base layer has embedded portion in the resist layer and exposed portion and having diameter substantially equal to or smaller than diameter of the embedded portion, and a second bump formed on the second pad and including second base and top plating layers such that the second base layer has embedded portion in the resist layer and exposed portion and having diameter substantially equal to or smaller than diameter of the embedded portion.