Solder alloy, solder paste, and electronic circuit board
AssigneeHarima Chemicals, Inc.
InventorsKazuki Ikeda, Kosuke Inoue, Kazuya Ichikawa, Tadashi Takemoto
Life of this patent
Estimating the term…
Abstract
A solder alloy substantially consists of tin, silver, indium, bismuth, and antimony. With respect to the total amount of the solder alloy, the content ratio of the silver is 2.8 mass % or more and 4 mass % or less; the content ratio of the indium is 6.2 mass % or more and 9.0 mass % or less; the content ratio of the bismuth is 0.7 mass % or more and 5.0 mass % or less; the content ratio of the antimony is 0.3 mass % or more and 5.0 mass % or less; and the content ratio of the tin is the remaining ratio and the value of A is 4.36 or less wherein A=0.87×[In content ratio (mass %)]−0.41×[Ag content ratio (mass %)]−0.82×[Sb content ratio (mass %)].
Claims6
A solder alloy consisting essentially of:
- tin, silver, indium, bismuth, and antimony, wherein
- with respect to the total amount of the solder alloy,
- the content ratio of the silver is 2.8 mass % or more and 4 mass % or less;
- the content ratio of the indium is 6.2 mass % or more and 9.0 mass % or less;
- the content ratio of the bismuth is 1.0 mass % or more and 5.0 mass % or less;
- the content ratio of the antimony is 1.0 mass % or more and 5.0 mass % or less;
- and
- the content ratio of the tin is the remaining ratio, and
- wherein the value of A in the following discriminant (1) is 4.36 or less,
- A=0.87×[In content ratio (mass %)]−0.41×[Ag content ratio (mass %)]−0.82×[Sb content ratio (mass %)] (1), and
- wherein the solder alloy satisfies:
- 1) Phase Transformation ranking of A or B, wherein ranking A corresponds to A:
- deformation of the solder alloy was not confirmed, and ranking B corresponds to B:
- deformation of the solder alloy was confirmed, but a bridge between solder alloys of lands that were adjacent to each other was not confirmed;
- 2) a Durability of a 3216 size ranking of A, wherein ranking A corresponds to A:
- a proportion of a crack was 70% or less of a total length of a fillet;
- and
- 3) a Breakage of Component ranking of A or B, wherein ranking A corresponds to A:
- a crack did not occur in a component electrode, and ranking B corresponds to B:
- a crack occurred in a component electrode, but rupture did not occur.
A solder alloy consisting essentially of:
- tin, silver, indium, bismuth, antimony, and at least one element selected from the group consisting of copper, nickel, cobalt, gallium, germanium, and phosphorus, wherein
- with respect to the total amount of the solder alloy,
- the content ratio of the silver is 2.8 mass % or more and 4 mass % or less;
- the content ratio of the indium is 6.2 mass % or more and 9.0 mass % or less;
- the content ratio of the bismuth is 1.0 mass % or more and 5.0 mass % or less;
- the content ratio of the antimony is 1.0 mass % or more and 5.0 mass % or less;
- the content ratio of the element is above 0 mass % and 1 mass % or less;
- and
- the content ratio of the tin is the remaining ratio, and
- wherein the value of A in the following discriminant (1) is 4.36 or less,
- A=0.87×[In content ratio (mass %)]−0.41×[Ag content ratio (mass %)]−0.82×[Sb content ratio (mass %)] (1), and
- wherein the solder alloy satisfies:
- 1) Phase Transformation ranking of A or B, wherein ranking A corresponds to A:
- deformation of the solder alloy was not confirmed, and ranking B corresponds to B:
- deformation of the solder alloy was confirmed, but a bridge between solder alloys of lands that were adjacent to each other was not confirmed;
- 2) a Durability of a 3216 size ranking of A, wherein ranking A corresponds to A:
- a proportion of a crack was 70% or less of a total length of a fillet;
- and
- 3) a Breakage of Component ranking of A or B, wherein ranking A corresponds to A:
- a crack did not occur in a component electrode, and ranking B corresponds to B:
- a crack occurred in a component electrode, but rupture did not occur.
Dependencies are inferred from the claim text.