(19)
(11) EP 0 762 800 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
23.04.1997 Bulletin 1997/17

(43) Date of publication A2:
12.03.1997 Bulletin 1997/11

(21) Application number: 96306415.9

(22) Date of filing: 04.09.1996
(51) International Patent Classification (IPC)6: H04R 1/06
(84) Designated Contracting States:
DE GB SE

(30) Priority: 07.09.1995 JP 229954/95
29.09.1995 JP 254090/95

(71) Applicant: STAR MICRONICS CO., LTD.
Shizuoka-shi, Shizuoka-ken 422 (JP)

(72) Inventors:
  • Ono, Jun c/o Nippon Mining & Metals Co. Ltd.
    minato-ku, Tokyo (JP)
  • Kubo, Masayoshi c/o Nippon Mining & Metals Co. Ltd
    koza-gun, Kanagawa-ken (JP)
  • Sone, Takahiro c/o Star Micronics Co. Ltd.
    Shizuoka-ken 422 (JP)
  • Suzuki, Kazushi c/o Star Micronics Co. Ltd.
    Shizuoka-ken 422 (JP)

(74) Representative: Hackney, Nigel John et al
Mewburn Ellis, York House, 23 Kingsway
London WC2B 6HP
London WC2B 6HP (GB)

   


(54) Lead frame for electroacoustic transducer and electroacoustic transducer


(57) A lead frame (1) for an electroacoustic transducer, forming leads of the electroacoustic transducer, comprising a metal sheet (2) made of a metal having elongation 20% or higher, a nickel undercoat deposit (3) of a thickness in the range from 0.01 to 2.0 µm formed on the metal sheet (2) by plating in a nickel plating bath containing no brightening agent, and a solder deposit (4) of a thickness in the range from 1.0 to 10 µm formed on the surface of the nickel undercoat deposit (3) by plating in a tin-lead plating bath containing no brightening agent. With the lead frame (1) formed by plating the metal sheet (2) as stated above, micro-cracking occurring in the bent corners of the metal sheet (2) and the solder deposit (4), when the outer leads of the lead frame (1) are bent at an angle of 90°, can be prevented.






Search report