Electronic device with external terminals and method of production of the same
AssigneeTDK Corporation
InventorsAkitoshi Yoshii, Kazuhiko Kikuchi, Takashi Kamiya, Hiromi Kikuchi
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Abstract
A multilayer ceramic capacitor with external terminals having terminal electrodes and external terminals of the electronic device body electrically bonded through a solder layer, wherein the solder layer is comprised of an Sn—Sb high temperature lead-free solder, the ratio between the Sn and Sb in this solder layer is, by ratio by weight percent, in a range of Sn/Sb=70/30 to 90/10, and the solder layer and terminal electrodes are formed between them with a diffusion layer formed by diffusion of a conductive ingredient of the terminal electrodes into the solder layer.
Claims17
An electronic device with external terminals having terminal electrodes and external terminals of the electronic device body electrically bonded through solder layers, wherein
- said solder layers are comprised of an Sn—Sb high temperature lead-free solder, the ratio of Sn and Sb in the solder layers being, by weight percent, within a range of Sn/Sb=70/30 to 90/10, and
- said solder layers and terminal electrodes are formed between them with diffusion layers formed by diffusion of the conductive ingredients of said terminal electrodes to the solder layers.
A electronic device with terminal electrodes having terminal electrodes and external terminals of the electronic device body electrically bonded through solder layers, wherein
- said solder layers and terminal electrodes are formed between them with diffusion layers having thicknesses of at least 5 μm formed by diffusion of conductive ingredients of said terminal electrodes into the solder layers.
A method of production of an electronic device with external terminals comprising the steps of:
- preparing a high temperature lead-free solder comprised of a cream solder having a metal composition of, by ratio of weight percent, Sn/Sb=70/30 to 90/10 and a solidus temperature of at least 240° C.,
- depositing said high temperature lead-free solder between the external terminals and external terminals of the electronic device body, and
- heating said terminal electrodes and external terminals to a temperature range of a maximum temperature of 310° C. to 340° C. and bonding them through solder layers,
- when heating and bonding said terminal electrodes and external terminals, conductive ingredients of said terminal electrodes diffusing into said solder layers and forming diffusion layers between said solder layers and external terminals.
A method of production of an electronic device with external terminals comprising the steps of:
- preparing a high temperature lead-free solder comprised of a cream solder having a metal composition of, by ratio of weight percent, Sn/Sb=approximately 90/10 and a solidus temperature of at least 240° C.,
- depositing said high temperature lead-free solder between the external terminals and external terminals of the electronic device body, and
- heating said terminal electrodes and external terminals to a temperature range of a maximum temperature of 325° C. to 350° C. and bonding them through solder layers,
- when heating and bonding said terminal electrodes and external terminals, conductive ingredients of said terminal electrodes diffusing into said solder layers and forming diffusion layers between said solder layers and external terminals.
Dependencies are inferred from the claim text.