Electronic component material and method for manufacturing the same, lead frame material and method for manufacturing the same, and semiconductor package

Abstract

Provided are a material for an electronic component and a method for producing the same, a lead frame material and a method for producing the same, and a semiconductor package, the material having high solder wettability even when heated on the assumption that the semiconductor package is assembled, and being capable of reducing discoloration in a high-temperature use environment or a corrosive atmosphere to make it difficult to cause an increase in conductor resistance or contact resistance due to a chemical change on a surface.SOLUTION: A material for electronic components 1 includes a substrate 2 made of a conductive material and a surface film 3 formed on at least a part of a surface 21 of the substrate 2, the surface film 3 includes a Ni-containing layer 31 containing Ni, and the Ni-containing layer 31 has an average crystal grain size in a range of 0.10 μm or more and 0.50 μm or less when viewed in a cross section including a thickness direction t of the material for electronic components 1, and an average of IQ values in the cross section obtained from crystal orientation analysis by an electron backscatter diffraction (EBSD) method is in a range of 1000 or more and 2500 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a material for electronic components and a method for manufacturing the same, a lead frame material and a method for manufacturing the same, and a semiconductor package. [Background technology]

[0002] Many resin-sealed semiconductor devices are incorporated into electronic devices, electrical devices, and the like. These resin-sealed semiconductor devices are formed by electrically connecting a lead frame material, which is formed by pressing or bending a plate-shaped material for electronic components, to a semiconductor element via wires or the like, and then sealing the resulting structure with a molded resin. In these resin-sealed semiconductor devices, the lead frame material is often coated with an exterior plating such as gold (Au), silver (Ag), or tin (Sn) to impart functions such as bonding, heat resistance, and sealing properties.

[0003] In recent years, in order to simplify the assembly process and reduce costs, pre-plated leadframes have been used, in which the surface of the leadframe is pre-plated with a coating (e.g., Ni / Pd / Au) that can improve wettability with solder when mounted on a printed circuit board.

[0004] For example, Patent Document 1 describes a lead frame material for a semiconductor device having multiple layers of metal film formed on the surface of the material, in which a Pd or Pd alloy film with a thickness of 0.3 μm or less is formed on the entire surface of the material directly or via an underlying metal film such as a Ni plating film, and an Au plating film with a thickness of 0.001 to 0.1 μm is formed on the Pd or Pd alloy film formed on the outer leads of the lead frame material, and it is claimed that this makes it possible to provide a lead frame material for a semiconductor device with particularly improved solderability.

[0005] On the other hand, as semiconductor packages become lighter, thinner, shorter, and smaller, there is a demand for thinner and smaller lead frame materials, and there is a demand for joints and connection terminals with high solder wettability to maintain a good bond even when subjected to thermal history such as heating to around 400°C during resin molding during assembly of the semiconductor package.

[0006] In this regard, Patent Document 2 describes an electronic component in which a nickel plating film containing germanium is formed on the surface of a conductive substrate in the connection terminal portion, and claims that this enables good bonding even when subjected to high-temperature thermal history, and provides an electronic component in which a plating film that has excellent heat resistance and solder wettability and can be made thinner is formed in the connection terminal portion. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2543619 [Patent Document 2] Patent No. 5042894 Summary of the Invention [Problem to be solved by the invention]

[0008] The nickel plating coatings used on these lead frame materials and electronic components can improve heat resistance and solder wettability. However, when the lead frame material is exposed to high-temperature environments of around 200°C or corrosive atmospheres, as is required in recent years for automotive applications, discoloration due to oxidation or corrosion can occur. Chemical changes such as surface oxidation and sulfurization can increase conductor resistance and contact resistance, which can lead to poor electrical conductivity and malfunction. Therefore, it has been found that there is still room for improvement in reducing discoloration of lead frame materials, especially in such high-temperature environments and corrosive atmospheres.

[0009] The object of the present invention is to provide a material for electronic components and a manufacturing method thereof, a lead frame material and a manufacturing method thereof, and a semiconductor package, which have high solder wettability even when heated at, for example, 400°C, assuming the assembly of a semiconductor package, and which have little discoloration even when placed in a high-temperature environment of around 200°C or in a corrosive atmosphere, and are less likely to cause increases in conductor resistance and contact resistance due to chemical changes on the surface. [Means for solving the problem]

[0010] As a result of intensive research and development to address the above-mentioned conventional problems, the present inventors have found that an electronic component material having at least a substrate made of a conductive material and a surface coating formed on at least a portion of the surface of the substrate, the surface coating includes a Ni-containing layer containing Ni, and that the Ni-containing layer has an average crystal grain size in the thickness direction cross section of the Ni-containing layer in the range of 0.10 μm to 0.50 μm, and an average IQ value obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) in the range of 1000 to 2500, can be obtained. This electronic component material has high solder wettability even when heated to, for example, 400°C, which is assumed during assembly of a semiconductor package, and is capable of reducing discoloration in high-temperature operating environments of around 200°C or in corrosive atmospheres. The present invention was completed based on this finding.

[0011] In order to achieve the above object, the gist of the present invention is as follows. (1) A material for electronic components having a substrate made of a conductive material and a surface coating formed on at least a portion of the surface of the substrate, wherein the surface coating has a Ni-containing layer containing Ni, and the Ni-containing layer has an average crystal grain size in the range of 0.10 μm to 0.50 μm when viewed in a cross section including the thickness direction of the material for electronic components, and the average IQ value in the cross section obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) is in the range of 1000 to 2500. (2) The material for electronic components according to (1) above, wherein the Ni-containing layer is made of a Ni alloy, and the Ni alloy contains one or more additive components selected from the group consisting of germanium (Ge), manganese (Mn), zinc (Zn), phosphorus (P), cobalt (Co), molybdenum (Mo) and tungsten (W), with the remainder consisting of Ni and inevitable impurities. (3) The material for electronic components according to (2) above, wherein the Ni alloy has an alloy composition containing the additive components in a total range of 0.01 mass % to 10.0 mass %. (4) The material for electronic components according to any one of (1) to (3) above, wherein the surface coating further comprises at least one surface coating layer on the Ni-containing layer. (5) The material for electronic components according to (4) above, wherein the surface coating layer is made of copper, a copper alloy, cobalt, a cobalt alloy, palladium, a palladium alloy, rhodium, a rhodium alloy, ruthenium, a ruthenium alloy, platinum, a platinum alloy, iridium, an iridium alloy, gold, a gold alloy, silver, a silver alloy, tin, a tin alloy, indium, or an indium alloy. (6) The material for electronic components according to any one of (1) to (5) above, wherein the substrate is made of copper, a copper alloy, iron, an iron alloy, aluminum, or an aluminum alloy. (7) A method for producing a material for electronic components according to any one of (1) to (6) above, comprising a coating formation step of forming the surface coating on at least a part of the surface of the substrate by electroplating. (8) A lead frame material having a substrate made of a conductive material and a surface coating formed on at least a portion of the surface of the substrate, wherein the surface coating has a Ni-containing layer containing Ni, and the Ni-containing layer has an average crystal grain size in the range of 0.10 μm to 0.60 μm when viewed in a cross section including the thickness direction of the lead frame material, and the average IQ value in the cross section obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) is in the range of 1200 to 2600. (9) A method for producing the lead frame material described in (8) above, comprising a coating formation step of forming the surface coating on at least a portion of the surface of the base by electroplating to obtain a material for electronic components, and a heat treatment step of subjecting the material for electronic components to heat treatment to obtain a lead frame material. (10) A semiconductor package having a lead frame formed using the lead frame material described in (8) above. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a material for electronic components and a manufacturing method thereof, a lead frame material and a manufacturing method thereof, and a semiconductor package, which have high solder wettability even when heated at, for example, 400°C, assuming the assembly of a semiconductor package, and which are capable of reducing discoloration in high-temperature environments of around 200°C or in corrosive atmospheres, and making it difficult for increases in conductor resistance and contact resistance due to chemical changes on the surface to occur. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view showing an example of a material for electronic components according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing another example of a material for electronic components according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Preferred embodiments of the material for electronic components and the method for producing the same, the lead frame material and the method for producing the same, and the semiconductor package of the present invention will be described in detail below.

[0015] <Materials for electronic components> As shown in FIG. 1 , a material for electronic components 1 according to the present invention has a substrate 2 made of a conductive material and a surface coating 3 formed on at least a part of a surface 21 of the substrate 2. The surface coating 3 has a Ni-containing layer 31 that contains Ni. The Ni-containing layer 31 has an average crystal grain size in the thickness direction t of the material for electronic components 1 (hereinafter, sometimes simply referred to as the "thickness direction t") of 0.10 μm or more and 0.50 μm or less, and an average IQ value in the cross section obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) is in the range of 1000 or more and 2500 or less.

[0016] In the electronic component material 1 of the present invention, by controlling the average IQ value in the cross section of the Ni-containing layer 31 including the thickness direction t to a range of 1000 to 2500, solder wettability can be improved both before and after heating, which is assumed to occur during the assembly of a semiconductor package. Furthermore, by controlling the average crystal grain size in the cross section of the Ni-containing layer 31 including the thickness direction t to a range of 0.10 μm to 0.50 μm, the area ratio of discoloration due to oxidation by oxygen gas or corrosive gas at high temperatures when the electronic component material 1 is placed in a high-temperature operating environment or a corrosive atmosphere can be reduced, thereby maintaining desired electrical and mechanical performance. Therefore, it is possible to provide an electronic component material and a manufacturing method thereof, a lead frame material and a manufacturing method thereof, and a semiconductor package, which have high solder wettability even when heated at, for example, 400°C, which is assumed to occur during the assembly of a semiconductor package, and which are capable of reducing discoloration in a high-temperature operating environment of around 200°C or in a corrosive atmosphere, and making it difficult for an increase in conductor resistance or contact resistance due to chemical changes on the surface.

[0017] The material for electronic components 1 according to the present invention has a substrate 2 made of a conductive material and a surface coating 3 formed on at least a part of the surface 21 of the substrate 2 .

[0018] [About the base] The base 2 is preferably made of a metal or alloy containing copper (Cu), iron (Fe), or aluminum (Al). More specifically, from the viewpoint of improving electrical conductivity and heat dissipation, the base 2 is preferably made of copper, a copper alloy, iron, an iron alloy, aluminum, or an aluminum alloy, and more preferably made of copper, a copper alloy, iron, or an iron alloy.

[0019] When the base 2 is made of an alloy, the alloy composition is not particularly limited and can be appropriately selected depending on the characteristics required of the lead frame material. Examples of copper alloys that can be used to make the base 2 include pure copper (oxygen-free copper (OFC): C1020 or tough pitch copper (TPC): C1100, etc.), as well as alloys listed by the Copper Development Association (CDA), such as C18045 (Cu-0.3Cr-0.25Sn-0.52Zn) and C19400 (Cu-2.3Fe-0.03P-0.15Zn). An example of an iron alloy that can be used to make the base 2 is 42 alloy (Fe-42Ni). The number before each element indicates the content in mass% of the alloy.

[0020] The base 2 is preferably in the form of a metal foil or alloy foil, and examples of such metal foil or alloy foil include rolled foil, electrolytic foil, etc. In particular, from the viewpoint of configuring the base 2 to have anisotropic mechanical properties, a rolled foil formed by press working or the like may be used.

[0021] The thickness of the substrate 2 is not particularly limited, but is, for example, in the range of 1 μm to 500 μm, preferably 5 μm to 200 μm.

[0022] [About the surface coating] The material for electronic components 1 has a surface coating 3 formed on at least a portion of the surface 21 of the substrate 2. Examples of the surface coating 3 include, in order from closest to the substrate 2, a Ni-containing layer 31 and a surface coating layer 32. The material for electronic components 1 of the present invention has at least the Ni-containing layer 31 as the surface coating 3. The surface coating 3 may be formed on the entire surface 21 of the substrate 2 as shown in FIG. 1 , or may be formed on only a portion of the surface 21 of the substrate 2.

[0023] (Ni-containing layer) The Ni-containing layer 31 is a layer containing nickel (Ni). When the average crystal grain size and the average IQ value of the Ni-containing layer 31 are set within predetermined ranges when viewed in a cross section including the thickness direction t of the material for electronic components 1, the Ni-containing layer 31 acts as a barrier layer on the surface of the base 2, reducing the diffusion of corrosive gases such as hydrogen sulfide and oxygen gas into the base 2, thereby reducing deterioration of the material for electronic components 1 due to oxidation by oxygen gas at high temperatures or oxidation by corrosive gases.

[0024] The average crystal grain size of the Ni-containing layer 31 of the electronic component material 1, more specifically, the average crystal grain size of the crystalline phase contained in the Ni-containing layer 31 when viewed in a cross section of the electronic component material 1 including the thickness direction t, is in the range of 0.10 μm to 0.50 μm. If the average crystal grain size of the Ni-containing layer 31 is less than 0.10 μm, the Ni-containing layer 31 becomes hard, making it difficult to process the electronic component material 1 into lead frame materials, etc. On the other hand, if the average crystal grain size of the Ni-containing layer 31 exceeds 0.50 μm, diffusion of corrosive gases and oxygen gases through grain boundaries occurs easily, resulting in reduced corrosion resistance of the electronic component material 1, particularly in high-temperature environments and corrosive atmospheres. Therefore, by controlling the average crystal grain size of the Ni-containing layer 31 of the electronic component material 1 to be in the range of 0.10 μm to 0.50 μm, it becomes easier to process the electronic component material 1 into lead frame materials, etc., and it is possible to reduce discoloration of the electronic component material 1 due to oxidation, etc.

[0025] The average crystal grain size of the crystalline phase contained in the Ni-containing layer 31 can be determined by a cutting method. More specifically, a cross section, which is finished using a cross-section polisher (manufactured by JEOL Ltd.) or the like and which includes the thickness direction t and the rolling direction of the base 2, is observed using a scanning electron microscope (SEM). In the obtained scanning electron microscope (SEM) image, ten line segments, each 5 μm long, parallel to the surface of the base 2 are drawn, and the total number of points where each line segment intersects with the boundaries of crystal grains is counted. The average length of each line segment defined by the boundaries of crystal grains is calculated using the following mathematical formula (I), thereby determining the average crystal grain size, which is the average length of each line segment. Average length of each line segment [μm] = 5 [μm] × 10 / (total number of intersections between line segments and grain boundaries) (I)

[0026] Furthermore, the Ni-containing layer 31 of the material for electronic components 1 has an average IQ value (hereinafter, sometimes simply referred to as the "average IQ value") in a cross section of the material for electronic components 1, including the thickness direction t, obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) method, in the range of 1000 to 2500. Here, if the average IQ value is less than 1000, grain boundaries become dominant in the Ni-containing layer 31, and the Ni-containing layer 31 does not function as a barrier layer on the surface of the base 2. On the other hand, if the average IQ value is greater than 2500, the number of grain boundaries becomes unnecessarily small, shortening the diffusion paths of corrosive gases, oxygen gases, and the like, and thereby causing significant corrosion of the base material. Therefore, by setting the average IQ value of the Ni-containing layer 31 of the material for electronic components 1 to be 1000 to 2500, the number of grain boundaries in the Ni-containing layer 31 becomes moderate, lengthening the diffusion paths of corrosive gases, oxygen gases, and the like, and thereby reducing the diffusion of corrosive gases, oxygen gases, and the like into the base 2.

[0027] The average IQ value of the Ni-containing layer 31 can be obtained from crystal orientation analysis data calculated using analysis software (OIM Analysis, manufactured by TSL Solutions) from crystal orientation data continuously measured using an EBSD detector (OIM5.0 HIKARI, manufactured by TSL Solutions) attached to a high-resolution scanning analytical electron microscope (JEOL Ltd., JSM-7001FA) for a cross section including the thickness direction t. Here, "EBSD" stands for Electron Backscatter Diffraction, a crystal orientation analysis technique that utilizes backscattered electron Kikuchi diffraction generated when a copper alloy sheet sample is irradiated with an electron beam in a scanning electron microscope (SEM). "OIM Analysis" is software for analyzing data measured by EBSD. Measurements can be performed on a cross section that includes the thickness direction t and the rolling direction of the substrate 2, which has been polished using a cross-section polisher (manufactured by JEOL Ltd.). The cross section can be measured at a magnification of 30,000x, with measurement intervals of 50 nm or less. Among these measurement points, measurement points with a reliability index CI value of 0.1 or less are excluded from the analysis, and the boundary where the orientation difference between adjacent measurement points is 5.00° or more is regarded as a grain boundary, and the average IQ value within the measurement region can be calculated. This measurement is performed for five different measurement regions within the cross section of the same Ni-containing layer 31, and the average of the five locations is calculated from the average IQ values ​​obtained for each measurement region, thereby calculating the average IQ value of the Ni-containing layer 31.

[0028] Here, the CI value is a value used as an index for indexing a crystal orientation analysis pattern obtained by the EBSD method and for evaluating whether the calculated crystal orientation is correct. In other words, the CI value is a value reflecting the reliability of the crystal orientation measured by the EBSD method in the cross section of the Ni-containing layer 31. This CI value can be calculated from the Map-Confidence Index of the analysis software (OIM Analysis, manufactured by TSL) by analyzing the crystal orientation data obtained in the cross section by the EBSD detector as described above.

[0029] The Ni-containing layer 31 is preferably made of a material containing Ni, and is preferably made of a Ni-based material such as metallic Ni or a Ni alloy. In particular, the Ni-containing layer 31 is preferably made of a Ni alloy. From the viewpoint of improving the heat resistance and corrosion resistance of the Ni-containing layer 31, the Ni alloy preferably contains one or more additive components selected from the group consisting of germanium (Ge), manganese (Mn), zinc (Zn), phosphorus (P), cobalt (Co), molybdenum (Mo), and tungsten (W), with the balance being Ni and unavoidable impurities. Alternatively, the additive component contained in the Ni alloy composition may be one or more additive components selected from the group consisting of germanium (Ge), manganese (Mn), zinc (Zn), and phosphorus (P).

[0030] The Ni alloy constituting the Ni-containing layer 31 preferably has an alloy composition containing one or more additive elements selected from the group consisting of germanium (Ge), manganese (Mn), zinc (Zn), phosphorus (P), cobalt (Co), molybdenum (Mo), and tungsten (W) in a total amount ranging from 0.01% to 10.0% by mass. In particular, by setting the total content of these additive elements to 0.01% by mass or more, the Ni alloy is sufficiently alloyed, further improving the heat resistance of the electronic component material 1 and further improving the solder wettability when a semiconductor package is formed. On the other hand, by setting the total content of these additive elements to 10.0% by mass or less, the additive elements are less likely to oxidize, thereby improving the corrosion resistance of not only the substrate 2 but also the Ni-containing layer 31, thereby further reducing the discoloration of the electronic component material 1. In addition, when the additional component contained in the alloy composition of the Ni alloy is one or more selected from the group consisting of germanium (Ge), manganese (Mn), zinc (Zn) and phosphorus (P), from the same viewpoint, it is preferable that the total content of these additional components is in the range of 0.01 mass% or more and 10.0 mass% or less.

[0031] Among the additive components, the germanium (Ge) content is preferably 0.01% by mass or more in order to further improve the solder wettability when a semiconductor package is formed. Also, the germanium (Ge) content is preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and even more preferably 2.0% by mass or less in order to improve the corrosion resistance of the Ni-containing layer 31.

[0032] The manganese (Mn) content is preferably 0.01% by mass or more in order to further improve the solder wettability when a semiconductor package is formed. Also, the manganese (Mn) content is preferably 7.0% by mass or less, and more preferably 4.0% by mass or less in order to improve the corrosion resistance of the Ni-containing layer 31.

[0033] The zinc (Zn) content is preferably 0.01% by mass or more in order to further improve the solder wettability when a semiconductor package is formed. Also, the zinc (Zn) content is preferably 10.0% by mass or less, and more preferably 5.0% by mass or less in order to improve the corrosion resistance of the Ni-containing layer 31.

[0034] The phosphorus (P) content is preferably 0.01% by mass or more in order to further improve the solder wettability when a semiconductor package is formed, and is preferably 5.0% by mass or less in order to improve the corrosion resistance of the Ni-containing layer 31.

[0035] The content of cobalt (Co) is preferably 0.01% by mass or more in order to further improve the solder wettability when a semiconductor package is formed, and is preferably 10.0% by mass or less in order to improve the corrosion resistance of the Ni-containing layer 31.

[0036] The content of molybdenum (Mo) is preferably 0.01% by mass or more in order to further improve the solder wettability when a semiconductor package is formed, and is preferably 7.0% by mass or less in order to improve the corrosion resistance of the Ni-containing layer 31.

[0037] The tungsten (W) content is preferably 0.01% by mass or more to further improve the solder wettability when a semiconductor package is formed, and is preferably 5.0% by mass or less to improve the corrosion resistance of the Ni-containing layer 31.

[0038] In addition to the aforementioned additive components, the Ni alloy consists of the remainder nickel (Ni) and unavoidable impurities. The term "unavoidable impurities" refers to those present in raw materials or those inevitably mixed in during the manufacturing process. These impurities are essentially unnecessary but are tolerated in trace amounts that do not affect the properties of the alloy. The upper limit of the content of the components that make up the unavoidable impurities is less than 0.01% by mass for each component, and the total amount of the unavoidable impurities can be 0.10% by mass.

[0039] The thickness of the Ni-containing layer 31 is not particularly limited, but can be, for example, in the range of 0.1 μm to 5.0 μm, preferably 0.5 μm to 1.5 μm. Here, by making the thickness of the Ni-containing layer 31 0.1 μm or more, the Ni-containing layer 31 further reduces the diffusion of the components of the base 2 to the surface, making it possible to prevent a decrease in solder wettability due to the diffusion of the components of the base 2 to the surface. On the other hand, by making the thickness of the Ni-containing layer 5.0 μm or less, it is possible to make the electronic component material 1 less likely to crack when bent.

[0040] (Surface coating layer) The surface coating 3 preferably further includes at least one surface coating layer 32 on the Ni-containing layer 31. This can further enhance the solder wettability of the material for electronic components 1. In addition, since the surface coating layer 32 covers the surface of the Ni-containing layer 31, the function of the Ni-containing layer 31 as a barrier layer on the surface of the base 2 is strengthened, which can further reduce the diffusion of corrosive gases such as hydrogen sulfide and oxygen gas into the base 2. As a result, deterioration of the material for electronic components 1 due to oxidation by oxygen gas at high temperatures or oxidation by corrosive gases can be further reduced.

[0041] The surface coating layer 32 is composed of a metal or alloy layer having a different composition from the Ni-containing layer 31. More specifically, the surface coating layer 32 is preferably composed of copper, a copper alloy, cobalt, a cobalt alloy, palladium, a palladium alloy, rhodium, a rhodium alloy, ruthenium, a ruthenium alloy, platinum, a platinum alloy, iridium, an iridium alloy, gold, a gold alloy, silver, a silver alloy, tin, a tin alloy, indium, or an indium alloy. Since the surface coating layer 32 is the surface that comes into contact with the outside of the electronic component material 1, by forming the surface coating layer 32 from at least one of these materials, the surface coating layer 32 is less susceptible to oxidation and the solder wettability can be further improved.

[0042] Here, the surface coating layer 32 may be composed of one layer or two or more layers. For example, as shown in the material 1A for electronic components in Fig. 2, when the surface coating layer 32 of the surface coating 3A is composed of two layers, the layer closer to the base 2 may be the first surface coating layer 32a, and the layer farther from the base 2 may be the second surface coating layer 32b. Furthermore, the surface coating layer 32 may be formed on a part of the surface of the Ni-containing layer 31 as shown in Fig. 2, or may be formed on the entire surface.

[0043] The surface coating layer 32 has a surface that comes into contact with the outside of the electronic component material 1 and preferably has excellent wettability with solder, etc. Therefore, the surface coating layer 32 is preferably made of gold, a gold alloy, palladium, a palladium alloy, silver, a silver alloy, tin, or a tin alloy. In particular, from the viewpoint of further enhancing wettability with solder, the surface coating layer 32 is preferably made of a gold-cobalt alloy, gold, silver, copper, or tin. In this case, when the surface coating layer 32 is composed of two or more layers, the layer farthest from the base 2 (for example, when the surface coating layer 32 is composed of two layers, the second surface coating layer 32b) is preferably made of a gold-cobalt alloy, gold, silver, copper, or tin.

[0044] <About the manufacturing method of materials for electronic components> The method for producing the material for electronic components 1 described above is not particularly limited, but from the viewpoint of easily controlling the average crystal grain size and the average IQ value of the Ni-containing layer 31, and from the viewpoint of easily controlling the content of additive components of the Ni alloy, particularly when the Ni-containing layer 31 is made of a Ni alloy, it is preferable that the method includes a coating formation step of forming the surface coating 3 on at least a part of the surface of the base 2 by electroplating.

[0045] An example of a method for manufacturing the material 1 for electronic components is to prepare a conductive substrate 2 whose size and thickness have been adjusted by pressing, and then perform cathodic electrolytic degreasing and pickling as pretreatments, followed by a coating formation step in which a surface coating 3 is formed on the substrate 2. Specific methods for forming the surface coating 3 in the coating formation step include electroplating, focused ion beam (FIB), and mechanical polishing. Among these, electroplating is particularly preferred to form an electroplated layer as the surface coating 3. For example, examples of conditions for forming an electroplated layer, which is a Ni-plated layer that is a Ni-containing layer 31, as the surface coating 3 in the coating formation step are shown below.

[0046] [Examples of electroplating layer formation conditions] Plating bath: 550g / L to 650g / L (Ni (atom) equivalent) of Ni salt excluding nickel chloride 30g / L to 40g / L of boric acid 30g / L~60g / L nickel chloride Plating conditions: Bath temperature 20℃~60℃, current density 10A / dm 2 ~80A / dm 2 , Magnetic stirrer stirring speed: 800 rpm to 1200 rpm

[0047] Here, examples of methods for controlling the average crystal grain size and average IQ value of the Ni-containing layer 31 include adjusting the content of Ni salt (excluding nickel chloride) in the plating bath (hereinafter simply referred to as the "Ni salt content") to a range of 550 g / L or more and 650 g / L or less in terms of Ni (atoms) when forming the Ni-containing layer 31 by electroplating, and performing stirring with a magnetic stirrer during electroplating while adjusting the stirring speed to a range of 800 rpm or more and 1200 rpm or less. By adjusting the content of Ni salt in the plating bath and adjusting the stirring speed of the magnetic stirrer to a range of 800 rpm or more and 1200 rpm or less in this manner, a material for electronic components 1 can be obtained in which the average crystal grain size of the crystalline phase in the Ni-containing layer 31 is in the range of 0.10 μm or more and 0.50 μm or less when viewed in a cross section including the thickness direction t, and the average IQ value in the cross section including the thickness direction t is in the range of 1000 or more and 2500 or less.

[0048] <About lead frame materials> Similar to the electronic component material 1 shown in FIG. 1 , the lead frame material 10 according to the present invention has a substrate 2 made of a conductive material and a surface coating 3 formed on at least a portion of the surface 21 of the substrate 2, with the surface coating 3 having a Ni-containing layer 31 containing Ni. On the other hand, similar to the electronic component material 1 described above, the Ni-containing layer 31 of the lead frame material 10 is composed of a Ni-based material, such as metallic Ni or a Ni alloy, but is primarily produced by subjecting the electronic component material 1 described above to heat treatment, and therefore has a different crystalline state from that of the electronic component material 1. Therefore, in this specification, the configuration of the lead frame material 10 other than the Ni-containing layer 31 is the same as that of the electronic component material 1, so description thereof will be omitted, and only the Ni-containing layer 31 will be described.

[0049] The Ni-containing layer 31 of the lead frame material 10 is a layer containing nickel (Ni). When viewed in a cross section of the lead frame material 10 including the thickness direction t, the average crystal grain size and the average IQ value are set within a predetermined range, so that the Ni-containing layer 31 acts as a barrier layer on the surface of the base 2, reducing the diffusion of corrosive gases such as hydrogen sulfide and oxygen gas into the base 2. This reduces deterioration of the lead frame material 10 due to oxidation by oxygen gas at high temperatures or oxidation by corrosive gases such as hydrogen sulfide gas.

[0050] The average crystal grain size of the Ni-containing layer 31 of the lead frame material 10, more specifically, the average crystal grain size of the crystalline phase contained in the Ni-containing layer 31 when viewed in a cross section of the lead frame material 10 including the thickness direction t, is in the range of 0.10 μm to 0.60 μm. Here, Ni-containing layers 31 having an average crystal grain size of less than 0.10 μm are difficult to obtain in practice because the Ni-containing layer 31 becomes hard, making it difficult to process the electronic component material 1 into the lead frame material 10. On the other hand, if the average crystal grain size of the Ni-containing layer 31 exceeds 0.60 μm, diffusion of corrosive gases, oxygen gas, and the like through grain boundaries occurs easily, and therefore the corrosion resistance of the lead frame material 10 decreases and discoloration easily occurs, particularly in high-temperature environments and corrosive atmospheres. Therefore, by controlling the average crystal grain size of the Ni-containing layer 31 to a range of 0.10 μm or more and 0.60 μm or less, and preferably to a range of 0.20 μm or more and 0.50 μm or less, discoloration of the lead frame material 10 due to oxidation or the like can be reduced.

[0051] Furthermore, the Ni-containing layer 31 of the lead frame material 10 has an average IQ value in a cross section of the lead frame material 10 including the thickness direction t, which is obtained by crystal orientation analysis using electron backscatter diffraction (EBSD), in the range of 1200 to 2600. Here, if the average IQ value is less than 1200, grain boundaries become dominant in the Ni-containing layer 31, and the Ni-containing layer 31 does not function as a barrier layer on the surface of the base 2. On the other hand, if the average IQ value is greater than 2600, the number of grain boundaries becomes unnecessarily small, shortening the diffusion paths of corrosive gases, oxygen gases, and the like, resulting in significant corrosion of the base 2 and making the lead frame material 10 more likely to discolor. Therefore, by setting the average IQ value of the Ni-containing layer 31 of the lead frame material 10 to 1200 to 2600, the number of grain boundaries in the Ni-containing layer 31 becomes moderate, lengthening the diffusion paths of corrosive gases, oxygen gases, and the like, and reducing the diffusion of corrosive gases, oxygen gases, and the like into the base 2.

[0052] The material constituting the Ni-containing layer 31 of the lead frame material 10 is composed of a material containing Ni, similar to the above-mentioned electronic component material 1, and is preferably composed of a Ni-based material such as metallic Ni or a Ni alloy. The alloy composition of the Ni alloy is the same as that of the above-mentioned electronic component material 1, and therefore will not be described here.

[0053] The thickness of the Ni-containing layer 31 of the lead frame material 10 is not particularly limited, but can be, for example, in the range of 0.1 μm to 5.0 μm. Here, by making the thickness of the Ni-containing layer 31 0.1 μm or more, the Ni-containing layer 31 further reduces the diffusion of the components of the base 2 to the surface, making it possible to prevent a decrease in solder wettability due to the diffusion of the components of the base 2 to the surface. On the other hand, by making the thickness of the Ni-containing layer 5.0 μm or less, it is possible to make the lead frame material 10 less likely to crack when bent.

[0054] <Lead frame material manufacturing method> The method for producing the lead frame material 10 described above is not particularly limited, but from the viewpoint of easily controlling the average crystal grain size and the average IQ value of the Ni-containing layer 31, and from the viewpoint of easily controlling the content of additive components of the Ni alloy, particularly when the Ni-containing layer 31 is made of a Ni alloy, it is preferable that the method include a coating formation step of forming a surface coating 3 by electroplating on at least a part of the surface of the base 2 to obtain the electronic component material 1, and a heat treatment step of subjecting the electronic component material 1 to heat treatment to obtain the lead frame material 10.

[0055] Among these, the film forming step can be carried out in the same manner as in the manufacturing method of the material 1 for electronic components.

[0056] On the other hand, the heat treatment process may be performed in conjunction with forming a resin mold on the surface to fix and protect the semiconductor element. The heating temperature in the heat treatment process is preferably in the range of 100°C to 400°C. When a typical lead frame material undergoes such a thermal history, the average crystal grain size and average IQ value of the Ni-containing layer 31 tend to increase, resulting in a decrease in corrosion resistance. In this regard, the lead frame material 10 of the present invention forms the Ni-plated layer, which is the Ni-containing layer 31, using the above-described electroplated layer formation conditions in the coating process. This suppresses grain boundary migration within the Ni-containing layer 31, even when heated in the heat treatment process, thereby maintaining the average crystal grain size and average IQ value within the desired range.

[0057] The heating time for the heat treatment in the heat treatment step is not particularly limited, but can be, for example, in the range of 10 seconds to 5 minutes.

[0058] The heat treatment in the heat treatment step is preferably carried out in a non-oxidizing atmosphere to prevent oxidation of the metals constituting the substrate 2 and surface coating 3 of the material for electronic components 1, and more specifically, is preferably carried out in an inert gas atmosphere or a reducing gas atmosphere. Here, examples of inert gases that can be used include N2, Ar, He, and mixed gases of two or more of these. Examples of reducing gases that can be used include H2, CO, CH4, and mixed gases of two or more of these, such as a mixed gas of H2 and CO.

[0059] In this way, by adjusting the content of Ni salt contained in the plating bath during electroplating in the coating formation process, adjusting the stirring speed of the magnetic stirrer to a range of 800 rpm or more and 1200 rpm or less, and setting the heating temperature of the heat treatment in the heat treatment process to a temperature range of 100°C or more and 400°C or less, a lead frame material 10 can be obtained in which the average crystal grain size of the crystalline phase contained in the Ni-containing layer 31 when viewed in a cross section including the thickness direction t is in a range of 0.10 μm or more and 0.60 μm or less, and the average IQ value in the cross section including the thickness direction t is in a range of 1200 or more and 2600 or less.

[0060] <Uses of lead frame materials> The lead frame material 10 of the present invention is used as a connection terminal for supporting and fixing a semiconductor element and for exchanging electricity and signals with the outside via wires, a printed circuit board, etc., and is preferably used, for example, in a semiconductor package having a lead frame formed using the lead frame material. Here, examples of semiconductor elements that can be mounted in a semiconductor package include, but are not limited to, transistors, capacitors, LEDs, etc.

[0061] Furthermore, the electronic component material 1 of the present invention has high solder wettability even when heated at, for example, 400°C, assuming the assembly of a semiconductor package, and therefore can be preferably used for semiconductor packages equipped with such lead frames. Furthermore, the electronic component material 1 and lead frame material 10 of the present invention are less likely to discolor due to oxidation or the like even in high-temperature environments or corrosive atmospheres, and are particularly less likely to cause failures or defects due to corrosion of the base 2, thereby achieving high reliability in semiconductor packages, particularly for in-vehicle applications.

[0062] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, but includes all aspects encompassed by the concept of the present invention and the scope of the claims, and can be modified in various ways within the scope of the present invention. [Example]

[0063] Next, in order to more clearly illustrate the effects of the present invention, examples of the present invention and comparative examples will be described. However, the present invention is not limited to these examples of the present invention.

[0064] <Pretreatment of the substrate> A conductive substrate 2 with a thickness of 0.1 mm, made of a metal or alloy of the type shown in Table 1 and previously formed into a size of 50 mm in length × 50 mm in width by pressing, was prepared and subjected to cathodic electro-degreasing and pickling as pretreatment.

[0065] Here, for cathodic electro-degreasing, an aqueous sodium hydroxide solution with a concentration of 60 g / L was placed in an electrolytic cell as a degreasing solution and heated. The substrate 2 was immersed in the heated degreasing solution heated to 60 °C and connected to the anode of the electrolytic cell, and electrolysis was carried out by applying an electric current at a current density of 2.5 A / dm 2 for 60 seconds.

[0066] Also, for pickling, after performing cathodic electro-degreasing, the substrate 2 was immersed in 10% by mass sulfuric acid at room temperature for 30 seconds. Here, for Example 3 of the present invention using 42 alloy as the substrate 2, after pickling, the substrate was immersed in 10% by mass hydrochloric acid at room temperature for 30 seconds.

[0067] <Formation of the Ni-containing layer> Thereafter, an Ni-containing layer 31 was formed on all surfaces (front surface, back surface, and side surfaces) of the substrate 2 by electroplating under the conditions shown below.

[0068] [Ni-Ge plating (when the "type of additive element" of the Ni-containing layer described in Table 1 is Ge)] For Examples 1 to 4 of the present invention, as an electroplating solution, an aqueous solution containing nickel (Ni) metal at a concentration in the range of 550 g / L to 650 g / L, 30 g / L of nickel chloride, 30 g / L of boric acid, and 100 mg / L of germanium oxide was prepared. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and at a temperature of 50 °C, 10 A / dm 2A current was passed through the plating electrolytic bath at a current density of 1000 rpm to form a Ni-containing layer 31. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was stirred at a stirring speed in the range of 800 rpm to 1200 rpm using a magnetic stirrer.

[0069] On the other hand, for Comparative Example 3, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 450 g / L, 30 g / L nickel chloride, 30 g / L boric acid, and 100 mg / L germanium oxide was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 55°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 kJ / min, thereby forming a Ni-containing layer 31 by electroplating. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was not stirred with a magnetic stirrer, and electroplating was performed in a static bath.

[0070] [Ni-Mn plating (when the "type of added element" of the Ni-containing layer listed in Table 1 is Mn)] For Inventive Example 5, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 650 g / L, 30 g / L nickel chloride, 30 g / L boric acid, and 5 g / L manganese sulfamate was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 50°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1,200 rpm to form the Ni-containing layer 31. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was stirred at a stirring speed of 1,200 rpm using a magnetic stirrer.

[0071] On the other hand, in Comparative Example 4, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 450 g / L, 30 g / L nickel chloride, 30 g / L boric acid, and 5 g / L manganese sulfamate was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 50°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 kJ / min, thereby forming a Ni-containing layer 31 by electroplating. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was not stirred with a magnetic stirrer, and electroplating was performed in a static bath.

[0072] [Ni-Zn plating (when the "type of added element" of the Ni-containing layer listed in Table 1 is Zn)] An aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration ranging from 550 g / L to 650 g / L, 30 g / L of boric acid, and 10 g / L of zinc sulfate was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 50°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 rpm to form a Ni-containing layer 31. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was stirred at a stirring speed in the range of 800 rpm to 1200 rpm using a magnetic stirrer.

[0073] [Ni-P plating (when the "type of added element" of the Ni-containing layer listed in Table 1 is P)] An aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration ranging from 550 g / L to 650 g / L, 30 g / L of boric acid, and 10 g / L of sodium hypophosphite was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 50°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 rpm to form a Ni-containing layer 31. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was stirred at a stirring speed in the range of 800 rpm to 1200 rpm using a magnetic stirrer.

[0074] [Ni-Zn-P plating (when the "type of added elements" of the Ni-containing layer listed in Table 1 is Zn and P)] An aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration of 550 g / L, 30 g / L boric acid, 10 g / L zinc sulfate, and 5 g / L sodium hypophosphite was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 50°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 rpm to form the Ni-containing layer 31. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was stirred at a stirring speed of 1000 rpm using a magnetic stirrer.

[0075] [Ni plating (when the "type of added element" of the Ni-containing layer listed in Table 1 is "no added element")] For Inventive Examples 11 and 12, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 550 g / L to 650 g / L, 30 g / L of nickel chloride, and 30 g / L of boric acid was prepared as the electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 50°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 rpm to form a Ni-containing layer 31. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was stirred at a stirring speed in the range of 800 rpm to 1200 rpm using a magnetic stirrer.

[0076] On the other hand, for Comparative Example 1, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 450 g / L, 30 g / L nickel chloride, and 30 g / L boric acid was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 55°C and a current of 10 A / dm 2A current was passed through the plating electrolytic bath at a current density of 1000 kJ / min, thereby forming a Ni-containing layer 31 by electroplating. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was not stirred with a magnetic stirrer, and electroplating was performed in a static bath.

[0077] For Comparative Example 2, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 550 g / L, 30 g / L of nickel chloride, and 30 g / L of boric acid was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 55°C and a current of 10 A / dm 2 A current was passed through the plating electrolytic bath at a current density of 1000 kJ / min, thereby forming a Ni-containing layer 31 by electroplating. While the Ni-containing layer 31 was being formed by passing a current through the plating electrolytic bath, the electroplating solution was not stirred with a magnetic stirrer, and electroplating was performed in a static bath.

[0078] <Formation of surface coating layer> Next, for Inventive Examples 1 to 9, 11, and 12 and Comparative Examples 2 to 4, a surface coating layer 32 was formed. In this case, the surface coating layer 32 was formed on all surfaces (front, back, and side) of the Ni-containing layer 31 by electroplating under the conditions shown below to the thickness shown in Table 1. Of these, for Inventive Examples 1 to 5, 11, and 12 and Comparative Examples 2 to 4, the surface coating layer 32 was configured as two layers, with a first surface coating layer 32a as the lower layer and a second surface coating layer 32b as the upper layer. For Inventive Examples 6 to 9, the surface coating layer 32 was formed as a single layer. The electroplating conditions and the thickness of the surface coating layer 32 at this time are listed in the column for the lower layer in Table 1, and no upper layer was formed. In this manner, the coating film formation step of forming the surface coating film 3 on the surface of the substrate 2 was performed, thereby obtaining materials for electronic components 1 for the Inventive Examples and Comparative Examples.

[0079] [Pd plating (when the "type of metal or alloy" of the underlayer listed in Table 1 is Pd)] An aqueous solution containing dichlorotetraamminepalladium (Pd(NH3)4Cl2) with a palladium (Pd) metal concentration of 45 g / L, 90 mL / L of 25 mass% ammonia water, 50 g / L of ammonium sulfate, and 10 g / L of Palla Sigma LN brightener (trade name, manufactured by Matsuda Sangyo Co., Ltd.) was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 60°C and a current of 5 A / dm 2 A current was passed through the electrode at a current density of 1000 to form the lower layer, ie, the first surface coating layer 32a, by electroplating.

[0080] [Au plating (when the "type of metal or alloy" of the underlayer or upper layer listed in Table 1 is Au)] An aqueous solution containing potassium gold cyanide with a gold (Au) metal concentration of 14.6 g / L, 150 g / L of citric acid, and 180 g / L of potassium citrate was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 40°C and a current of 1 A / dm 2 By passing a current at a current density of 1000 kJ / cm, a first surface coating layer 32a serving as a lower layer or a second surface coating layer 32b serving as an upper layer was formed by electroplating.

[0081] [Sn plating (when the "type of metal or alloy" of the underlayer listed in Table 1 is Sn)] An aqueous solution containing tin sulfate with a tin (Sn) metal concentration of 80 g / L, 50 mL / L of sulfuric acid, and 5 mL / L of UTB513Y (manufactured by Ishihara Chemical Co., Ltd.) was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 20°C and a current of 5 A / dm 2 A current was passed through the electrode at a current density of 1000 to form the lower layer, ie, the first surface coating layer 32a, by electroplating.

[0082] [Ag plating (when the "type of metal or alloy" of the underlayer listed in Table 1 is Ag)] An aqueous solution containing silver cyanide with a silver (Ag) metal concentration of 93 g / L and potassium cyanide at 132 g / L was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating solution was applied at a temperature of 20°C and a current of 1 A / dm 2 A current was passed through the electrode at a current density of 1000 to form the lower layer, ie, the first surface coating layer 32a, by electroplating.

[0083] [AuCo plating (when the "type of metal or alloy" of the underlayer listed in Table 1 is AuCo)] An aqueous solution containing potassium gold cyanide with a gold (Au) metal concentration of 10 g / L, cobalt carbonate with a cobalt (Co) metal concentration of 0.1 g / L, citric acid at 100 g / L, and dipotassium hydrogen phosphate at 20 g / L was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic cell with an inner diameter of 80 mm, and the plating was conducted at a temperature of 40°C and a current of 1 A / dm 2 A current was passed through the electrode at a current density of 1000 to form the lower layer, ie, the first surface coating layer 32a, by electroplating.

[0084] <Making lead frame materials> The obtained electronic component material 1 was subjected to a heat treatment process in which it was heated on a hot plate at a heating temperature of 400°C for a heating time of 30 seconds, simulating the thermal history that occurs during the assembly of a semiconductor package, particularly during resin molding, to produce a lead frame material 10.

[0085] <Various measurement and evaluation methods> Next, the properties of the obtained electronic component material 1 and the lead frame material 10 obtained by subjecting the electronic component material 1 to a heat treatment process were measured and evaluated as follows. The properties of each layer constituting the electronic component material 1 and the lead frame material 10 were measured at any time during or after the production of the electronic component material 1 and the lead frame material 10.

[0086] [1] Measurement of the average grain size of the Ni-containing layer The average grain size of the crystalline phase contained in the Ni-containing layer 31 of the electronic component material 1 and the lead frame material 10 was determined by a cross-section method. More specifically, cross sections of the electronic component material 1 and the lead frame material 10, which were finished using a cross-section polisher (manufactured by JEOL Ltd.) or the like and included the thickness direction t and the rolling direction of the substrate 2, were observed using a scanning electron microscope (SEM). In the resulting SEM images, ten 5 μm-long line segments parallel to the surface of the substrate 2 were drawn, and the total number of intersections between each line segment and the boundaries of the crystal grains was counted. The average length of each line segment defined by the boundaries of the crystal grains was calculated using the following formula (I), thereby determining the average grain size, which is the average length of each line segment. The results are shown in Table 1. Average length of each line segment [μm] = 5 [μm] × 10 / (total number of intersections between line segments and grain boundaries) (I)

[0087] [2] Measurement of the average IQ value of the Ni-containing layer The average IQ values ​​of the Ni-containing layer 31 of the electronic component material 1 and the lead frame material 10 were obtained from crystal orientation analysis data calculated using analysis software (OIM Analysis, TSL Solutions) from crystal orientation data continuously measured using an EBSD detector (OIM5.0 HIKARI, TSL Solutions) attached to a high-resolution scanning analytical electron microscope (JEOL Ltd., JSM-7001FA) for each cross section including the thickness direction t. The measurements were performed on cross sections including the thickness direction t and the rolling direction of the substrate 2, which were polished using a cross-section polisher (JEOL Ltd.), etc. The cross-sectional measurement magnification was 30,000x, and measurements were performed at intervals of 50 nm or less. Measurement points with a reliability index (CI) value of 0.1 or less were excluded from the analysis, and the average IQ value within the measurement area was calculated by considering boundaries with an orientation difference of 5.00° or more between adjacent measurement points as grain boundaries. This measurement was performed on five different measurement regions within the cross section of the same Ni-containing layer 31, and the average IQ value for each measurement region was calculated from the average IQ value for the five regions to calculate the average IQ value of the Ni-containing layer 31 for each of the electronic component material 1 and the lead frame material 10. The results are shown in Table 1.

[0088] [3] Evaluation of solder wettability For each of the obtained electronic component materials 1 and lead frame materials 10, the solder wetting time was measured using a solder checker (SAT-5100 (trade name, manufactured by Rhesca Corporation)) by the wetting balance method specified in JIS Z3198-4, Lead-Free Solder Test Methods - Part 4: Wetting Balance and Contact Angle Methods. The solder bath temperature was 250°C, Sn-3Ag-0.5Cu solder was used, the immersion speed was 10 mm / sec, the immersion depth was 2 mm, and the immersion time was 10 seconds. The flux used was isopropyl alcohol containing 25% by mass of rosin.

[0089] For each of the electronic component material 1 and the lead frame material 10, when the measured zero cross time (the time t0 at which wetting begins) was 2.0 seconds or less, the material was evaluated as "◎" for particularly excellent solder wettability. When the measured zero cross time (the time t0 at which wetting begins) was more than 2.0 seconds and less than 10.0 seconds, the material was evaluated as "◯" for good solder wettability. On the other hand, when the measured zero cross time (the time t0 at which wetting begins) was more than 10.0 seconds, the material was evaluated as "×" for failure in terms of solder wettability. The results are shown in Table 2.

[0090] [4] Evaluation of discoloration when placed in a high-temperature environment The electronic component material 1 and the lead frame material 10 were used as test materials and heated at 200°C for 100 hours in a thermostatic chamber containing air at normal pressure. The surface of the test material after heating was magnified with a digital microscope, and the ratio of the discolored area to the observed area was measured. This measurement was performed on five different measurement areas of the same test material, and the ratio of the discolored area to the observed area obtained for each measurement area was averaged to determine the measured value of the ratio of the discolored area when placed in a 200°C environment.

[0091] For each of the electronic component material 1 and the lead frame material 10, if the measured percentage of discolored area when placed in a 200°C environment was less than 10%, the material was evaluated as "Excellent" because it showed almost no discoloration when placed in a high-temperature environment around 200°C and the conductor resistance and contact resistance of the test material were less likely to increase compared to before being placed in this high-temperature environment. Furthermore, if the measured percentage of discolored area was 10% or more but less than 30%, the material was evaluated as "Good" because it showed little discoloration when placed in a high-temperature environment around 200°C and the conductor resistance and contact resistance of the test material were less likely to increase compared to before being placed in this high-temperature environment. On the other hand, if the measured percentage of discolored area was 30% or more, the material showed significant discoloration when placed in a high-temperature environment around 200°C and the conductor resistance and contact resistance of the test material were more likely to increase compared to before being placed in this high-temperature environment. This was evaluated as "X" because it failed. The results are shown in Table 2.

[0092] [5] Evaluation of discoloration when placed in a corrosive atmosphere A corrosion test was conducted on each of the electronic component material 1 and the lead frame material 10 in accordance with the mixed gas flow corrosion test described in JIS C 60068-2-60. The gas composition was 0.10 ppm H2S, 0.20 ppm NO2, and 0.02 ppm Cl2. The electronic component material 1 and the lead frame material 10 were used as test materials and maintained for 24 hours in an environment at a temperature of 30°C and a humidity of 75% RH. After the corrosion test, the surface of the test material was magnified with a digital microscope to measure the ratio of the discolored area to the observed area. This measurement was performed on five different measurement areas of the same test material, and the ratio of the discolored area to the observed area obtained for each measurement area was averaged to determine the measured value of the ratio of the discolored area when placed in a corrosive atmosphere.

[0093] For each of the electronic component material 1 and the lead frame material 10, if the measured percentage of the discolored area when placed in a corrosive atmosphere was less than 10%, the material was evaluated as "Excellent" because it showed almost no discoloration when placed in a corrosive atmosphere and was less likely to increase in the conductor resistance or contact resistance of the test material compared to before being placed in the corrosive atmosphere. Furthermore, if the measured percentage of the discolored area was 10% or more but less than 30%, the material was evaluated as "Good" because it showed little discoloration when placed in a corrosive atmosphere and was less likely to increase in the conductor resistance or contact resistance of the test material compared to before being placed in the corrosive atmosphere. On the other hand, if the measured percentage of the discolored area was 30% or more, the material showed significant discoloration when placed in a corrosive atmosphere and was more likely to increase in the conductor resistance or contact resistance of the test material compared to before being placed in the corrosive atmosphere. This was evaluated as "X" because it failed. The results are shown in Table 2.

[0094] [6] Overall rating Of these evaluation results, for the four evaluation results regarding the solder wettability of the electronic component material, the solder wettability of the lead frame material, the percentage of discolored area when placed in a usage environment of 200°C, and the percentage of discolored area when placed in a corrosive atmosphere, if all four were rated "◎," the electronic component material had high solder wettability even when heated to around 400°C, simulating the assembly of semiconductor packages, and was particularly excellent in terms of its resistance to discoloration in a high-temperature usage environment of around 200°C or a corrosive atmosphere. Furthermore, if all four of these evaluation results were rated "◎" or "○" (excluding cases where all four were rated "◎"), the electronic component material had high solder wettability even when heated to around 400°C, simulating the assembly of semiconductor packages, and was excellent in terms of its resistance to discoloration in a high-temperature usage environment of around 200°C or a corrosive atmosphere, and was also evaluated as "○." On the other hand, if at least one of these four evaluation results was marked "X," it was evaluated as "X" because the solder wettability at least either before or after heating, which simulates the assembly of a semiconductor package, was unacceptable, or the product was prone to discoloration in a high-temperature operating environment or a corrosive atmosphere. The results are shown in Table 2.

[0095] [Table 1]

[0096] [Table 2]

[0097] From the results in Table 1, the electronic component materials and lead frame materials of Inventive Examples 1 to 12 had Ni-containing layer 31 with an average crystal grain size when viewed in a cross section including the thickness direction t, and an average IQ value in this cross section, all of which were within the appropriate range of the present invention. The electronic component materials and lead frame materials of Inventive Examples 1 to 12 were evaluated as either "◎" or "◯" in four categories: solder wettability of the electronic component material, solder wettability of the lead frame material, the percentage of discolored area when placed in a 200°C usage environment, and the percentage of discolored area when placed in a corrosive atmosphere.

[0098] In contrast, the electrical contact materials of Comparative Examples 1 and 4, in which the concentration of nickel (Ni) metal in the electroplating solution when forming the Ni-containing layer 31 was low and the electroplating solution was not stirred with a magnetic stirrer, had average IQ values ​​when viewed in a cross section including the thickness direction t that were greater than the appropriate range of the present invention, and the three evaluation results regarding the solder wettability of the lead frame material, the percentage of discolored area when placed in an operating environment of 200°C, and the percentage of discolored area when placed in a corrosive atmosphere were all evaluated as ``X.''

[0099] Furthermore, the electrical contact material of Comparative Example 2, in which the electroplating solution was not stirred with a magnetic stirrer, had an average IQ value when viewed in a cross section including the thickness direction t that was greater than the appropriate range of the present invention, and the results of the three evaluations regarding the solder wettability of the lead frame material, the percentage of discolored area when placed in an operating environment of 200°C, and the percentage of discolored area when placed in a corrosive atmosphere were all rated as "X."

[0100] Furthermore, the electrical contact material of Comparative Example 3, in which the concentration of nickel (Ni) metal in the electroplating solution when forming the Ni-containing layer 31 was low and the electroplating solution was not stirred with a magnetic stirrer, had an average crystal grain size when viewed in a cross section including the thickness direction t that was larger than the appropriate range of the present invention, and both of the evaluation results regarding the percentage of discolored area when placed in a usage environment of 200°C and the percentage of discolored area when placed in a corrosive atmosphere were evaluated as ``X.''

[0101] Therefore, it was revealed that the electronic component materials 1 and lead frame materials 10 of Examples 1 to 12 of the present invention have high solder wettability, even when the electronic component materials are heated to around 400°C, as is the case when assembling a semiconductor package, and they also reduce discoloration in high-temperature operating environments of around 200°C or in corrosive atmospheres, making it less likely that an increase in conductor resistance or contact resistance will occur due to chemical changes on the surface. [Explanation of symbols]

[0102] 1. 1A Materials for electronic components 10, 10A lead frame material 2 Base 21 Surface of the substrate 3, 3A surface coating 31 Ni-containing layer 32 Surface coating layer 32a First surface coating layer (or lower layer) 32b Second surface coating layer (or upper layer) t Thickness direction of electronic component material (or lead frame material)

Claims

1. A material for electronic components having a substrate made of a conductive material and a surface coating formed on at least a part of the surface of the substrate, the surface coating has a Ni-containing layer containing Ni, The Ni-containing layer is The average crystal grain size is in the range of 0.10 μm or more and 0.50 μm or less when viewed in a cross section including the thickness direction of the material for electronic components, and A material for electronic components, wherein an average IQ value in the cross section obtained by crystal orientation analysis using an electron backscatter diffraction (EBSD) method is in the range of 1000 or more and 2500 or less.

2. the Ni-containing layer is made of a Ni alloy, 2. The material for electronic components according to claim 1, wherein the Ni alloy has an alloy composition containing one or more additive components selected from the group consisting of germanium (Ge), manganese (Mn), zinc (Zn), phosphorus (P), cobalt (Co), molybdenum (Mo), and tungsten (W), with the balance consisting of Ni and inevitable impurities.

3. 3. The material for electronic components according to claim 2, wherein the Ni alloy has an alloy composition containing the additive components in a total amount within a range of 0.01 mass % to 10.0 mass %.

4. 2. The material for electronic components according to claim 1, wherein the surface coating further comprises at least one surface coating layer on the Ni-containing layer.

5. 5. The material for electronic components according to claim 4, wherein the surface coating layer comprises copper, a copper alloy, cobalt, a cobalt alloy, palladium, a palladium alloy, rhodium, a rhodium alloy, ruthenium, a ruthenium alloy, platinum, a platinum alloy, iridium, an iridium alloy, gold, a gold alloy, silver, a silver alloy, tin, a tin alloy, indium, or an indium alloy.

6. 2. The material for electronic components according to claim 1, wherein the substrate is made of copper, a copper alloy, iron, an iron alloy, aluminum, or an aluminum alloy.

7. A method for producing the material for electronic components according to any one of claims 1 to 6, comprising the steps of: A method for producing a material for electronic components, comprising a coating formation step of forming the surface coating on at least a portion of the surface of the substrate by electroplating.

8. A lead frame material having a substrate made of a conductive material and a surface coating formed on at least a portion of the surface of the substrate, the surface coating has a Ni-containing layer containing Ni, The Ni-containing layer is When viewed in a cross section including the thickness direction of the lead frame material, the average crystal grain size is in the range of 0.10 μm or more and 0.60 μm or less, and A lead frame material, wherein the average IQ value in the cross section obtained by crystal orientation analysis using an electron backscatter diffraction (EBSD) method is in the range of 1200 or more and 2600 or less.

9. 9. A method for manufacturing a lead frame material according to claim 8, comprising: a coating formation step of forming the surface coating on at least a part of the surface of the substrate by electroplating to obtain a material for electronic components; a heat treatment step of subjecting the electronic component material to a heat treatment to obtain a lead frame material; A method for manufacturing a lead frame material, comprising:

10. A semiconductor package having a lead frame formed using the lead frame material according to claim 8.

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