Matsushita Electric Industrial Co., Ltd.

Other

Panasonic Corporation

Senju Metal Industry Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Hisahiko Yoshida

Masahiko Hirata

Toshihiko Taguchi

Takashi Nagashima

Kunihito Takaura

Atsushi Yamaguchi

Yoshitaka Toyoda

Tsukasa Ohnishi

Arata Kishi

Takao Hisazumi

Naomichi Ohashi

Tetsuhiko Isobe

Yasuo Yokota

Mamoru Senna

Hiroji Noguchi

Takashi Ohashi

Setsuko Tadokoro

In a case where a first mounted substrate to which a semiconductor element is bounded by solder is mounted on a second substrate, connection strength becomes low, when the first mounted substrate is bonded to the second substrate by using a solder having a low melting point. A mounted structure, in which a first mounted substrate on which a semiconductor element is bonded by using a first solder having a melting point of 217&#xb0; C. or more, is mounted on a second substrate, includes plural bonding parts bonding the first mounted substrate to the second substrate; and a reinforcing member formed around the bonding part. Each of the bonding parts contains a second solder having a melting point, that is lower than the melting point of the first solder, and a space exists, in which the reinforcing members do not exist, between the bonding parts neighboring each other.

Mounted structure and manufacturing method of mounted structure

An electronic device including a semiconductor device with a plurality of bump electrodes, a mounting board connected to the semiconductor device, thermally expandable particles, and adhesive. The thermally expandable particles are provided on the sides of the semiconductor device and the surface of the mounting board around a projected area of the semiconductor device. The adhesive is provided on the sides of the semiconductor device and the surface of the mounting board such that it covers the area of thermally expandable particles. This improves the impact resistance of the semiconductor device soldered onto the mounting board, and also facilitates removal of the semiconductor device from the mounting board when the semiconductor device needs repair.

Electronic device and manufacturing method

A semiconductor device mounting structure includes a semiconductor device whose electrodes are aligned on its one main face; a circuit board having board electrodes electrically connected to the electrodes of the semiconductor device by solder bumps; and curable resin applied between at least the side face of the semiconductor device and the circuit board. Multiple types of thermally expandable particles with different expansion temperatures are mixed in this curable resin. This structure offers the semiconductor device mounting structure that is highly resistant to impact and suited for mass production, its manufacturing method, and a removal method of the semiconductor device. In addition, this structure facilitates repair and reworking, leaving almost no adhesive residue on the circuit board after repair. Stress applied to the circuit board during repair can also be minimized.

Semiconductor device mounting structure, manufacturing method, and removal method of semiconductor device

The present invention provides a Sn&#x2014;Zn based lead-free solder which can prevent peeling of solder from soldered portions even after the passage of long periods after soldering of portions to be soldered made of Cu. A Sn&#x2014;Zn based lead-free solder according to the present invention comprises 5-10 mass percent of Zn, a total of 0.005-1.0 mass percent of at least one substance selected from the group consisting of Au, Pt, Pd, Fe, and Sb, optionally a total of at most 15 mass percent of at least one substance selected from the group consisting of Bi and In, and a remainder of Sn. This Sn&#x2014;Zn based lead-free solder can be made into a solder paste using a rosin flux containing a halide such as an amine hydrochloride as an activator.

Lead-free solder and soldered article

A solder paste comprising a powder of a Zn-containing Sn-based, lead-free solder mixed with an activator-containing rosin-based flux to which 0.5-10.0 wt % of isocyanuric acid or a haloalkyl ester thereof is added can prevent the formation of solder balls and voids during reflow soldering and exhibit good solderability. A solder paste comprising a powder of an Ag- or Zn-containing Sn-based, lead-free solder mixed with an activator-containing rosin-based flux to which 0.01-10.0 wt % of a salicylamide compound also does not exhibit a change in viscosity and exhibits good solderability.

Solder paste

A lead-free solder paste comprises an Sn&mdash;Zn based lead-free solder powder mixed with a flux. The flux contains at least one aromatic hydroxycarboxylic acid selected from the group consisting of aromatic carboxylic acids having one hydroxyl group in a meta position (such as 3-hydroxy-2-methylbenzoic acid) and aromatic carboxylic acids having at least two hydroxyl groups (such as dihydroxynaphthoic acid or dihydroxybenzoic acid) in an amount of 0.1-10.0 mass %. The flux may further include 0.5-20 mass % of an aliphatic hydroxy carboxylic acid (such as hydroxyoleic acid).

A solder paste having a powder of a Zn-containing solder alloy such as an Sn&mdash;Zn based alloy in admixture with a soldering flux such as a rosin flux is improved by adding from 0.1% to 5.0% by weight of a glycidyl ether compound such as alkyl, alkenyl, or aryl glycidyl ether. The improved solder paste has increased resistance to aging and to concomitant deterioration in solderability caused by reaction of Zn in the solder alloy with ingredients in the flux and has a substantially extended shelf life.

Lead-free zinc-containing solder paste

An organic acid salt is deposited on the surface of a solder powder containing Sn and Zn. Alternatively, 0.5 to 10 wt. % of a nonionic surfactant is added to a flux. By a method comprising such a procedure, provided are a lead-free solder powder and solder paste having good soldering characteristics wherein the reaction of an activating component with an alloy component in a flux is suppressed.

Growing community of inventors

Osaka, Japan

Hisahiko Yoshida