A solder composition of the invention includes: a flux composition containing a component (A) in a form of a rosin-based resin, a component (B) in a form of an activator, a component (C) in a form of a solvent and a component (D) in a form of a thixotropic agent; and a component (E) in a form of a solder powder. The component (C) in a form of the solvent contains a component (C1) in a form of a isobornyl cyclohexanol and a component (C2) in a form of a solvent whose viscosity at 20 degrees C. is 10 mPa.Math.s or less and whose boiling point ranges from 220 degrees C. to 245 degrees C.

One aspect of the present invention is a method for manufacturing an electronic component, the method including: a first step of applying a metal paste containing metal particles onto a polymer compact in a prescribed pattern to form a metal paste layer; a second step of sintering the metal particles to form metal wiring; a third step of applying a solder paste containing solder particles and a resin component onto the metal wiring to form a solder paste layer; a fourth step of disposing an electronic element on the solder paste layer; and a fifth step of heating the solder paste layer so as to form a solder layer bonding the metal wiring and the electronic element, and so as to form a resin layer covering at least a portion of the solder layer.

There is a problem that contact resistance increases due to formation of an oxide film on a contact interface or biting of abrasion powder caused by micro-sliding when a contact connecting portion of a connection terminal including non-noble metal members is exposed to high temperature environment or a repetitious temperature cycle. An object of the present invention is to provide an in-vehicle electronic module that has connection reliability equivalent to that of the conventional in-vehicle electronic module even when being placed in the environment of an engine compartment and can achieve cost reduction by reducing the number of parts and assembly steps. The electronic module includes a mounting board having a circuit board on which an electronic component is mounted, and a case member for accommodating and protecting the mounting board from surrounding environment, The electronic module has a connection structure in which a portion of the circuit board is protruded to the outside through an opening of the case and inserts a board terminal into an external female connector to obtain electrical continuity, and a portion of the case member forms a connector housing that receives the female connector and isolates a space in which the board terminal is present from surrounding environment and an insulating resin member for fixing the circuit board in the case is integrally molded or joined with the circuit board.

In one embodiment, an electronic system includes a printed circuit board, one or more packaged semiconductor devices, and a vapor chamber having a top and a bottom and enclosing a sealed cavity that is partially filled with a coolant. The vapor chamber comprises a thermo-conductive and electro-conductive material. The top of the vapor chamber has one or more depressions formed therein, each depression receiving and thermo-conductively connected to at least part of a bottom of a corresponding packaged semiconductor device, which is mounted through a corresponding aperture in the PCB. A heat sink may be thermo-conductively attached to the bottom of the vapor chamber.

The wired circuit board includes a conductive layer having a terminal; a gold plated layer provided on the surface of the terminal; and a solder layer provided on the surface of the gold plated layer and provided so that the terminal and the electronic component can be electrically connected. The solder layer is made of a solder composition containing Sn, Bi, Cu and/or Ni, and the thickness T.sub.solder of the solder layer relative to the thickness T.sub.Au of the gold plated layer is 16 or more.

A pane, includes a substrate, an electrically conductive structure on a region of the substrate, a layer of a solder material on a region of the electrically conductive structure, and at least two soldering points of the at least one electrical connection element on the solder material, wherein the at least two soldering points form at least one contact surface between the at least one electrical connection element and the electrically conductive structure, and a shape of the at least one contact surface has at least one segment of an oval, an ellipse, or a circle with a central angle α of at least 90°.

As electronic equipment has become smaller in size, printed circuit boards which cannot be subjected to cleaning have been developed, and a no-clean lead-free solder paste is becoming necessary. In order for a solder paste not to require cleaning, it is necessary that the color of the residue be transparent and that the residue be non-tacky. A maleated rosin, which is a rosin suited for no-clean paste, has a high acid value so it is not suitable for a flux for lead-free solder. As a means of suppressing a reaction between a flux containing a maleated rosin and a Sn—Ag—Cu based solder alloy powder, a Sn—Ag—Cu—Sb based solder alloy powder is used which adds 1-8 mass % of Sb to a Sn—Ag—Cu based solder alloy. As a result, it is possible to provide a solder paste which has the excellent effect that the solder paste does not easily undergo changes over time and has a long pot life.

An electronic component mounting system is disclosed. An elapsed time acquiring section acquires an elapsed time from printing onto circuit board by solder printer. A raising and lowering operation changing section changes raising and lowering operation of component holding tool based on the elapsed time from printing acquired by the elapsed time acquiring section. A mounter mounts an electronic component on the solder printed on circuit board by performing raising and lowering of the component holding tool at the raising and lowering operation changed by the raising and lowering operation changing section.

A mechanically-stable and thermally-conductive interface device between a semiconductor die and a package for the die, and related method of fabrication, comprising: a semiconductor die; a package for the die; a surface area-enhancing pattern on the package and/or the die; and die attach materials between the die and the package, the die attach materials attaching the die to the package through an interface provided by the die attach materials; wherein: an effective bonding area between the die attach materials and the package and/or the die is greater with the pattern than without the pattern; and the increase of the effective bonding area simultaneously increases the surface area for thermal transport between the package and/or the die, and the die attach materials; and increases the surface area for stably attaching the at least one of the package and the die to the die attach materials.

Provided are a lead-free solder alloy which consists of Sb in an amount of more than 3.0% but 10% or less by mass, and the balance including Sn, and others.