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US 2023/0402364 A1Published application
Leadframe with a metal oxide coating and method of forming the same
AssigneeSTMicroelectronics International N.V.
InventorLuca Maria Carlo DI DIO
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Abstract
A leadframe including a metal oxide layer on at least a portion of the leadframe are disclosed. More specifically, leadframes with a metal layer and a metal oxide layer formed on one or more leads before a tin finish plating layer is formed are described. The layers of metal and metal oxide between the one or more leads and the tin finish plating layer reduce the formation of tin whiskers, thus reducing the likelihood of shorting and improving the overall reliability of the package structure and device produced.
Claims20
A method, comprising:
- forming a metal layer on a lead of a copper leadframe and on a die pad of the leadframe;
- forming a metal oxide layer on the metal layer on the lead and on the die pad;
- placing a die on the die pad, wherein the metal layer and the metal oxide layer are between the die and the die pad after placing the die on the die pad;
- forming a bonding wire extending from the die and contacting the metal oxide layer at a first portion of the lead
- encapsulating the die and a first portion of the lead in a molding compound, wherein the molding compound is in contact with the metal oxide layer at the first portion of the lead;
- and
- forming a tin layer on a second portion of the lead, wherein the tin layer is not covered by the molding compound in cross section, wherein the tin layer abuts a side of the molding compound.
4 more elements
A method, comprising:
- a semiconductor die on the die pad;
- forming a metal oxide layer on a lead of a copper leadframe and on a die pad of the leadframe;
- between the die and the die pad;
- forming a tin layer on at least a second portion of the copper leadframe, the metal oxide layer being between the tin layer and the copper leadframe;
- placing a die on the die pad, wherein the metal oxide layer is between the die and the die pad;
- and
- encapsulating, with a molding compound, the die pad, a first portion of the lead, and a bonding wire extending from the die and contacting the metal oxide layer at the first portion of the lead, wherein the molding compound is in contact with the metal oxide layer at the first portion of the lead, wherein the tin layer is not covered by the molding compound in cross-section, wherein the tin layer abuts a side of the molding compound.
4 more elements
A method, comprising:
- forming a copper layer on a lead of a leadframe and on a die pad of the leadframe;
- forming a metal layer on the copper layer on the lead and the die pad;
- and
- forming a metal oxide layer on the metal layer on the lead and on the die pad;
- placing a die on the die pad, wherein the metal layer and the metal oxide layer are between the die and the die pad;
- forming a bonding wire extending from the die and contacting the metal oxide layer at the first portion of the lead;
- encapsulating, in a molding compound, the die pad, the bonding wire, and a first portion of the lead, wherein the molding compound is in contact with the metal oxide layer at the first portion of the lead;
- and
- forming a tin layer on a second portion of the lead, wherein the tin layer is not covered by the molding compound in cross-section, wherein the tin layer abuts a side of the molding compound.
6 more elements
Dependencies are inferred from the claim text.