Laminate and circuit board
Provided are a laminate including a silver layer on a substrate, in which the silver layer includes a surface in which Kurtosis of a roughness curve satisfies at least one of Condition (i) the change rate of Kurtosis is greater than or equal to 50% under conditions of a temperature of 85° C. and a relative humidity of 85% after 240 hours have elapsed and Condition (ii) the change rate of Kurtosis is greater than or equal to 200% under conditions of a temperature of 85° C. and a relative humidity of 85% after 480 hours have elapsed, and a circuit board in which an electronic component is mounted on the surface of the laminate through a conductive joint portion.
1. A method for manufacturing a circuit board, the method comprising:
attaching a composition for an adhesion layer onto a substrate to form an adhesion layer, wherein the substrate is a polycarbonate (PC)/ABS resin alloy,
attaching a silver ink composition onto the adhesion layer, and heat treating the silver ink composition at 60° C. to 80° C. to form a silver layer,
wherein the silver ink composition comprises silver carboxylate, a nitrogen-containing compound, and an additive, and the additive is a reducing agent or an acetylene alcohol, and
wherein the silver layer includes a surface in which Kurtosis of a roughness curve satisfies at least one of Conditions (i) and (ii) described below,
(i) a change rate of Kurtosis is greater than or equal to 50% under conditions of a temperature of 85° C. and a relative humidity of 85% after 240 hours have elapsed, and
(ii) a change rate of Kurtosis is greater than or equal to 200% under conditions of a temperature of 85° C. and a relative humidity of 85% after 480 hours have elapsed,
the Kurtosis of the roughness curve is a value obtained by Expression (I) described below,
Rku
=
1
Rq
4
[
1
ℓ
∫
0
ℓ
Z
4
(
x
)
dx
]
(
I
)
wherein, in Expression (I), Rq represents a root-mean-square height, 1 represents a reference length which becomes non-dimensional by the fourth power of the root-mean-square height Rq, and Z(x) represents the roughness curve,
mounting an electronic component on the surface of the silver layer, wherein the Kurtosis of a roughness curve for the surface of the silver layer satisfies at least one of Conditions (i) and (ii) described above, through a conductive joint portion, and
when a test of placing the silver layer for 480 hours under conditions of a temperature of 85° C. and a relative humidity of 85% is performed, a change rate of the joining force between the silver layer and the electronic component is greater than or equal to −50%.
2. The method for manufacturing a circuit board according to claim 1 ,
wherein a thickness of the substrate is 10 μm to 10000 μm, and a thickness of the silver layer is 0.01 μm to 5 μm.
3. The method for manufacturing a circuit board according to claim 1 ,
wherein a ratio of the weight of metal silver with respect to the total weight of the silver layer is 99 to 99.9 mass%.
4. The method for manufacturing a circuit board according to claim 1 ,
wherein the Kurtosis of the roughness curve is obtained by measuring a surface shape of the silver layer of the laminate from an upper portion with respect to the surface by using a shape measurement laser microscope.
5. The method for manufacturing a circuit board according to claim 1 ,
wherein the Kurtosis of the roughness curve is obtained by measuring a shape of a sectional surface which is exposed by cutting or machining the silver layer of the laminate from an upper portion with respect to the sectional surface by using a shape measurement laser microscope.
6. The method for manufacturing a circuit board according to claim 1 ,
in the silver ink composition, a blended amount of the nitrogen-containing compound is 0.2 mol to 15 mol per 1 mol of a blended amount of the silver carboxylate.
7. The method for manufacturing a circuit board according to claim 1 , wherein the adhesion layer is formed by polymerizing an urethane acrylate resin having a polycarbonate skeleton and has 0.5 μm to 4 μm.
8. A method for manufacturing a circuit board, the method comprising:
attaching a composition for an adhesion layer onto a substrate to form an adhesion layer, wherein the substrate is a polycarbonate (PC)/ABS resin alloy,
attaching a silver ink composition onto the adhesion layer, heat treating the silver ink composition at 60° C. to 80° C. to form a silver layer, and
mounting an electronic component on the surface of the silver layer, wherein the Kurtosis of a roughness curve for the surface of the silver layer satisfies at least one of Conditions (i) and (ii) described below, through a conductive joint portion;
(i) a change rate of Kurtosis is greater than or equal to 50% under conditions of a temperature of 85° C. and a relative humidity of 85% after 240 hours have elapsed, and
(ii) a change rate of Kurtosis is greater than or equal to 200% under conditions of a temperature of 85° C. and a relative humidity of 85% after 480 hours have elapsed,
the Kurtosis of the roughness curve is a value obtained by Expression (I) described below,
Rku
=
1
Rq
4
[
1
ℓ
∫
0
ℓ
Z
4
(
x
)
dx
]
(
1
)
wherein, in Expression (I), Rq represents a root-mean-square height, 1 represents a reference length which becomes non-dimensional by the fourth power of the root-mean-square height Rq, and Z(x) represents the roughness curve,
wherein the silver ink composition comprises silver carboxylate, a nitrogen-containing compound, and an additive, and the additive is a reducing agent or an acetylene alcohol,
wherein the adhesion layer is formed by polymerizing a urethane acrylate resin having a polycarbonate skeleton, the adhesion layer having a thickness of 0.5 μm to 10 μm, and
when a test of placing the silver layer for 480 hours under conditions of a temperature of 85° C. and a relative humidity of 85% is performed, a change rate of the joining force between the silver layer and the electronic component is greater than or equal to −50%.
9. The method for manufacturing a circuit board according to claim 8 ,
wherein the conductive joint portion is a joining layer formed by curing a conductive adhesive agent, or a solder layer.
10. A method for manufacturing a circuit board, the method comprising:
attaching a composition for an adhesion layer onto a substrate to form an adhesion layer, wherein the substrate is a polycarbonate (PC)/ABS resin alloy,
attaching a silver ink composition onto the adhesion layer, heat treating the silver ink composition at 60° C. to 80° C. to form a silver layer, and
mounting an electronic component on the surface of the silver layer, wherein the Kurtosis of a roughness curve for the surface of the silver layer satisfies at least one of Conditions (i) and (ii) described below, through a conductive joint portion;
(i) a change rate of Kurtosis is greater than or equal to 50% under conditions of a temperature of 85° C. and a relative humidity of 85% after 240 hours have elapsed, and
(ii) a change rate of Kurtosis is greater than or equal to 200% under conditions of a temperature of 85° C. and a relative humidity of 85% after 480 hours have elapsed,
the Kurtosis of the roughness curve is a value obtained by Expression (I) described below,
Rku
=
1
Rq
4
[
1
ℓ
∫
0
ℓ
Z
4
(
x
)
dx
]
(
1
)
wherein, in Expression (I), Rq represents a root-mean-square height, 1 represents a reference length which becomes non-dimensional by the fourth power of the root-mean-square height Rq, and Z(x) represents the roughness curve, and
wherein the silver ink composition comprises silver carboxylate, a nitrogen-containing compound, and an additive, and the additive is a reducing agent or an acetylene alcohol,
wherein the adhesion layer is formed by using a silane coupling agent, the adhesion layer having a thickness of 0.5 pm to 10 μm,
when a test of placing the silver layer for 480 hours under conditions of a temperature of 85° C. and a relative humidity of 85% is performed, a change rate of the joining force between the silver layer and the electronic component is greater than or equal to −50%.
11. The method for manufacturing a circuit board according to claim 10 ,
wherein the silane coupling agent is a compound denoted by General Formula (3) described below,
wherein, in General Formula (3), R 11 represents an alkyl group having 1 to 5 carbon atoms, an alkoxyalkyl group or an alkylcarbonyl group; R 12 represents an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 12 carbon atoms; R 13 represents an alkylene group having 1 to 10 carbon atoms; R 14 represents an alkylene group having 1 to 5 carbon atoms, one or more methylene groups among the alkylene groups may be substituted with a carbonyl group; Z represents an amino group, a mercapto group, or an aryl group having 6 to 12 carbon atoms; m1 represents 2 or 3, a plurality of R 11 may be identical to each other or different from each other; m2 and m3 each independently represent 0 or 1, and when Z is an amino group, at least one of m2 and m3 represents 1.