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

Abstract

To provide a material for an electronic component which has high solder wettability even when it is heated on the assumption that a semiconductor package is assembled, and hardly causes insulation failure due to deposition of atoms constituting a substrate on the surface of a lead frame by ion migration even when it is used under a dry-wet repetition occurrence environment in which a dry state and a wet state repeatedly occur.SOLUTION: The material 1 for electronic parts has a base body 2 made of a conductive material and a surface film 3 formed on at least a part of the surface 2 of the base body 2, the surface film 3 has a Ni-containing layer 3 1 containing Ni, the average crystal grain size of the Ni-containing layer 3 1 is in a range of 0.10 μm or more and 0.50 μm or less, the average value of KAM in the cross section is in a range of 0.6° or more and 2.0° or less, and the mode value of KAM in the cross section is 0.5° or more.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 semiconductor devices having multiple layers of metal film formed on the surface of a material (substrate), 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 semiconductor devices 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 (base) in the connection terminal portion, and claims that this makes it possible to provide an electronic component in which a plating film is formed in the connection terminal portion that allows for good bonding even when subjected to high-temperature thermal history, has excellent heat resistance and solder wettability, and can be made thinner. [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 in these lead frame materials and electronic components can improve heat resistance and solder wettability. However, as semiconductor packages become lighter, thinner, shorter, and smaller, when used in an environment where dry and wet conditions alternate, if moisture adheres to the surface of the lead frame material during voltage application, conductive metal atoms constituting the substrate are ionized on the surface of the lead frame material, and the ionized metal atoms diffuse to the cathode side of the lead frame through ion migration, causing the ionized metal atoms to deposit on the cathode side of the lead frame, which then electrically connects with the anode side, potentially resulting in poor insulation. Therefore, it has been found that there is still room for improvement in terms of making ion migration to the surface of the lead frame less likely to occur in such an environment where dry and wet conditions alternate.

[0009] The object of the present invention is to provide 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, which have high solder wettability even when heated as in the assembly of a semiconductor package, and which are less likely to cause insulation defects caused by atoms constituting the base material precipitating on the surface of the lead frame due to ion migration even when used in an environment where dry and wet conditions occur repeatedly. [Means for solving the problem]

[0010] As a result of extensive research and development to address the above-mentioned conventional problems, the 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 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, an average KAM in the thickness direction cross section obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) in the range of 0.60° to 2.00°, and a mode KAM in the thickness direction cross section of 0.5° or greater, can be obtained. This electronic component material has high solder wettability even when heated as in the case of assembling semiconductor packages, and exhibits minimal deposition of atoms constituting the substrate on the lead frame surface due to ion migration, even when used in an environment where dry and wet conditions alternate. 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 value of KAM in the cross section obtained by crystal orientation analysis using an electron backscatter diffraction (EBSD) method is in the range of 0.60° to 2.00°, and the mode of KAM in the cross section is 0.5° or more. (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) A method for producing a material for electronic components according to any one of (1) to (5) above, comprising a coating formation step of forming the surface coating on at least a part of the surface of the substrate by electroplating. (7) 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 value of KAM in the cross section obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) is in the range of 0.50° to 2.00°, and the most frequent value of KAM in the cross section is 0.4° or more. (8) A method for manufacturing a lead frame material as described in (7) 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. (9) A semiconductor package having a lead frame formed using the lead frame material described in (7) 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 in the manner assumed during the assembly of a semiconductor package, and which are able to reduce the occurrence of insulation defects caused by precipitation of atoms constituting the base on the surface of a lead frame due to ion migration even when used in an environment where dry and wet conditions alternate. [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. [Figure 3] 3A and 3B are diagrams showing an example of a test device used to evaluate ion migration resistance in examples of the present invention and comparative examples, where FIG. 3A is a schematic diagram of the main part and FIG. 3B is an electrical circuit diagram. 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 containing Ni. The Ni-containing layer 31 has an average crystal grain size 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 of the material for electronic components 1 (hereinafter simply referred to as the "thickness direction t"). The average value of KAM in the cross section, obtained by crystal orientation analysis using an electron backscatter diffraction (EBSD) method, is in the range of 0.60° or more and 2.00° or less, and the mode of KAM in the cross section is 0.5° or more.

[0016] In the material for electronic components 1 of the present invention, the average crystal grain size in the cross section of the Ni-containing layer 31 including the thickness direction t is controlled to a range of 0.10 μm or more and 0.50 μm or less, the average value of KAM in the cross section of the Ni-containing layer 31 including the thickness direction t is controlled to a range of 0.60° or more and 2.00° or less, and the mode of KAM in the cross section is controlled to 0.5° or more. As a result, the material has high solder wettability even when heated as simulating the assembly of a semiconductor package, and is less likely to cause insulation defects due to ion migration, in which atoms constituting the base precipitate on the surface of a lead frame, even when used in an alternating dry-wet environment where dry and wet states occur repeatedly, particularly in a harsh environment where salt is present in addition to moisture, as is simulating a seaside environment such as an offshore wind power generation environment.

[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 substrate 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 substrate 2 is preferably made of copper, a copper alloy, iron, an iron alloy, aluminum, or an aluminum alloy, more preferably copper, a copper alloy, iron, or an iron alloy, and even more preferably copper or a copper alloy. The substrate 2 made of copper or a copper alloy is particularly prone to ion migration, but by forming the electronic component material 1 described above, it is possible to reduce precipitation of atoms constituting the substrate 2 on the surface of a lead frame due to ion migration, even when used in an environment where dry and wet conditions alternate.

[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 properties 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). 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 viewed in a cross section including the thickness direction t of the material for electronic components 1, the Ni-containing layer 31 has an average crystal grain size and an average value and mode of KAM within predetermined ranges, which reduces diffusion of atoms constituting the base 2 through the Ni-containing layer 31, thereby reducing insulation defects due to ion migration in which atoms constituting the base 2 precipitate on the surface of the lead frame.

[0024] The average crystal grain size of the Ni-containing layer 31 of the material for electronic components 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 material for electronic components 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 material for electronic components 1 into a lead frame material, etc. On the other hand, if the average crystal grain size of the Ni-containing layer 31 exceeds 0.50 μm, the solder wettability of the Ni-containing layer 31 decreases. Furthermore, if the average crystal grain size of the Ni-containing layer 31 exceeds 0.50 μm, the atoms constituting the base 2 are likely to diffuse inside the Ni-containing layer 31 through grain boundaries. Therefore, when the material for electronic components 1 is used in an environment where dry and wet conditions alternate, the atoms constituting the base 2 are likely to precipitate on the surface of the lead frame. Therefore, in the Ni-containing layer 31 of the material for electronic components 1, the average crystal grain size is controlled to be in the range of 0.10 μm or more and 0.50 μm or less, preferably in the range of 0.10 μm or more and 0.45 μm or less, which makes it easier to process the material for electronic components 1 into lead frame materials and the like, and also reduces insulation defects due to ion migration.

[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 electronic component material 1 has an average value of KAM (Kernel Average Misorientation) (hereinafter, simply referred to as "average KAM") in a cross section of the electronic component material 1, including the thickness direction t, obtained by crystal orientation analysis using electron backscatter diffraction (EBSD), in the range of 0.60° to 2.00°. Here, if the average KAM value is less than 0.60°, strain in the Ni-containing layer 31 is reduced, and atoms constituting the base 2 are more likely to diffuse inside the Ni-containing layer 31. On the other hand, if the average KAM value is greater than 2.00°, strain in the Ni-containing layer 31 becomes excessive, and therefore adhesion of the Ni-containing layer 31 to a surface coating layer 32 (described later) and solder wettability are reduced. Therefore, in the Ni-containing layer 31 of the material for electronic components 1, by setting the average value of the KAM in the range of 0.60° or more and 2.00° or less, the strain in the Ni-containing layer 31 becomes appropriately large, which makes it possible to reduce the diffusion of atoms constituting the base 2 into the Ni-containing layer 31 and to improve the solder wettability.

[0027] Furthermore, the Ni-containing layer 31 of the material for electronic components 1 has a KAM mode (hereinafter sometimes simply referred to as "KAM mode") of 0.5° or more 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). If the KAM mode is less than 0.5°, the strain distribution in the Ni-containing layer 31 becomes more uneven, which makes it easier for atoms constituting the base 2 to diffuse into the Ni-containing layer 31. Therefore, in the Ni-containing layer 31 of the material for electronic components 1, by making the KAM mode 0.5° or more, the strain distribution in the Ni-containing layer 31 becomes approximately uniform, thereby reducing the diffusion of atoms constituting the base 2 into the Ni-containing layer 31.

[0028] The average and mode values ​​of the KAM 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 cross sections including the thickness direction t that have 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 in analysis using analysis software are excluded from the analysis. The boundaries where the misorientation between adjacent measurement points is 5.00° or more are considered to be grain boundaries. The average KAM value, which represents the crystal orientation misorientation between the measurement points, can be calculated for each measurement area. This measurement is performed for five different measurement areas within the same cross section of the Ni-containing layer 31, and the average of the five KAM values ​​obtained for each measurement area is calculated to calculate the average KAM of the Ni-containing layer 31. Furthermore, the KAM values ​​of all measurement points to be analyzed within these five measurement areas are rounded to the nearest tenth to obtain a frequency distribution in 0.1° increments. The most frequent value in this frequency distribution can be used as the mode of KAM.

[0029] 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.

[0030] 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 further improving the solder wettability of the lead frame obtained from the electronic component material 1, 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), zinc (Zn), phosphorus (P), cobalt (Co), and molybdenum (Mo).

[0031] 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% by mass 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 reducing the likelihood of ion migration of atoms constituting the base 2 to the surface of the lead frame. On the other hand, by setting the total content of these additive elements to 10.0% by mass or less, the atoms constituting the base 2 are further reduced in thermal diffusion to the surface of the lead frame, due to the formation of an intermetallic compound between Ni and the additive elements. Furthermore, 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), zinc (Zn), phosphorus (P), cobalt (Co) and molybdenum (Mo), 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.

[0032] Of the added components, the content of germanium (Ge) is preferably 0.01% by mass or more from the viewpoint of making it more difficult for the atoms constituting the base 2 to migrate ionically to the surface of the lead frame. Also, the content of germanium (Ge) is preferably 10.0% by mass or less, and more preferably 8.0% by mass or less, from the viewpoint of making it more difficult for the atoms constituting the base 2 to undergo thermal diffusion by making it more difficult for an intermetallic compound to be formed with Ni.

[0033] The manganese (Mn) content is preferably 0.01% by mass or more from the viewpoint of making it more difficult for the atoms constituting the base 2 to migrate ionically to the surface of the lead frame. The manganese (Mn) content is preferably 7.0% by mass or less from the viewpoint of making it more difficult for the atoms constituting the base 2 to thermally diffuse by making it more difficult for the atoms constituting the base 2 to form an intermetallic compound with Ni.

[0034] The zinc (Zn) content is preferably 0.01% by mass or more, from the viewpoint of making it more difficult for the atoms constituting the base 2 to migrate ionically to the surface of the lead frame. The zinc (Zn) content is preferably 10.0% by mass or less, and more preferably 4.0% by mass or less, from the viewpoint of making it more difficult for the atoms constituting the base 2 to thermally diffuse by making it more difficult for the atoms to form an intermetallic compound with Ni.

[0035] The phosphorus (P) content is preferably 0.01% by mass or more from the viewpoint of making it more difficult for the atoms constituting the base 2 to migrate ionically to the surface of the lead frame. The phosphorus (P) content is preferably 5.0% by mass or less, and more preferably 1.0% by mass or less, from the viewpoint of making it more difficult for the atoms constituting the base 2 to thermally diffuse by making it more difficult for the atoms constituting the base 2 to form an intermetallic compound with Ni.

[0036] The cobalt (Co) content is preferably 0.01% by mass or more, from the viewpoint of making it more difficult for the atoms constituting the base 2 to migrate ionically to the surface of the lead frame. The cobalt (Co) content is preferably 10.0% by mass or less, and more preferably 5.0% by mass or less, from the viewpoint of making it more difficult for the atoms constituting the base 2 to undergo thermal diffusion by making it more difficult for the atoms to form an intermetallic compound with Ni.

[0037] The molybdenum (Mo) content is preferably 0.01% by mass or more, from the viewpoint of making it more difficult for ion migration of atoms constituting the base 2 to occur to the surface of the lead frame. Furthermore, the molybdenum (Mo) content is preferably 7.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 1.0% by mass or less, from the viewpoint of making it more difficult for thermal diffusion of atoms constituting the base 2 to occur by making it more difficult for an intermetallic compound to be formed with Ni.

[0038] The tungsten (W) content is preferably 0.01% by mass or more from the viewpoint of making it more difficult for the atoms constituting the base 2 to migrate ionically to the surface of the lead frame. The tungsten (W) content is preferably 5.0% by mass or less from the viewpoint of making it more difficult for the atoms constituting the base 2 to thermally diffuse by making it more difficult for the atoms constituting the base 2 to form an intermetallic compound with Ni.

[0039] 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.

[0040] 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. Here, by making the thickness of the Ni-containing layer 31 0.1 μm or more, the path along which atoms constituting the base 2 diffuse inside the Ni-containing layer 31 is lengthened, thereby further reducing the deposition of atoms constituting the base 2 on the surface of the lead frame material 10, making it possible to further reduce the occurrence of insulation defects due to ion migration. On the other hand, by making the thickness of the Ni-containing layer 31 5.0 μm or less, it is possible to make the electronic component material 1 less likely to crack when bent.

[0041] (Surface coating layer) The surface coating 3 preferably further includes at least one surface coating layer 32 on the Ni-containing layer 31. The surface coating layer 32 has a surface that comes into contact with the outside of the material for electronic components 1, and the presence of the surface coating layer 32 can further enhance the solder wettability of the material for electronic components 1. Furthermore, since the surface coating layer 32 covers the surface of the Ni-containing layer 31, the deposition of atoms constituting the base 2 on the surface of the material for electronic components 1 is further reduced, making it possible to further reduce the occurrence of insulation defects due to ion migration. In addition, since the surface coating layer 32 covers the surface of the Ni-containing layer 31, the surface of the base 2 of the Ni-containing layer 31 is protected, making it possible to reduce the occurrence of oxidation of the base 2.

[0042] 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.

[0043] 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.

[0044] The surface coating layer 32 has a surface that comes into contact with the outside of the electronic component material 1, and is preferably resistant to oxidation and has excellent wettability with solder, etc. Therefore, the surface coating layer 6 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-palladium laminate, gold, silver, tin, or a gold-cobalt alloy. Here, 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 gold, silver, tin, or a gold-cobalt alloy.

[0045] <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 of the Ni-containing layer 31 and the average and mode values ​​of KAM, 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.

[0046] 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.

[0047] [Examples of electroplating layer formation conditions] Plating bath: 60g / L to 170g / L (Ni (atom) equivalent) of Ni salts 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 1A / dm 2 ~20A / dm 2 ,

[0048] The average crystal grain size and the average and mode values ​​of the KAM of the Ni-containing layer 31 can be controlled, for example, by forming the Ni-containing layer 31 by multi-stage electroplating, which involves repeatedly applying current to a plating electrolytic bath and rinsing with water. Multi-stage electroplating can be performed by repeating the steps of electroplating in a plating electrolytic bath for 1 to 5 seconds under the above-described plating conditions and removing the substrate 2 from the plating electrolytic bath and rinsing with water. By performing multi-stage electroplating in this manner, a material for electronic components 1 can be obtained in which, when viewed in a cross section including the thickness direction t, the average crystal grain size of the crystalline phase contained in the Ni-containing layer 31 is in the range of 0.10 μm to 0.50 μm, the average KAM value in the cross section including the thickness direction t is in the range of 0.60° to 2.00°, and the mode KAM value in the cross section is 0.5° or more. In particular, when the Ni-containing layer 31 contains an additive component, it is preferable to adjust the content of the additive component contained in the plating bath to a range of 1.0 g / L or more and 80 g / L or less, from the viewpoint of suppressing nickel grain growth and controlling the average crystal grain size of the crystalline phase within a desired range.

[0049] <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.

[0050] The Ni-containing layer 31 of the lead frame material 10 is a layer containing nickel (Ni), and by setting the average crystal grain size and the average and mode values ​​of KAM within predetermined ranges when viewed in a cross section including the thickness direction t of the lead frame material 10, diffusion of atoms constituting the base 2 through the inside of the Ni-containing layer 31 is reduced, thereby reducing insulation defects due to ion migration in which atoms constituting the base 2 precipitate on the surface of the lead frame.

[0051] 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 with 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, the solder wettability of the Ni-containing layer 31 decreases. Furthermore, if the average crystal grain size of the Ni-containing layer 31 exceeds 0.60 μm, the atoms constituting the base 2 are more likely to diffuse inside the Ni-containing layer 31 through grain boundaries. Therefore, when the lead frame is used in an environment where dry and wet conditions alternate, the atoms constituting the base 2 are more likely to precipitate on the surface of the lead frame. 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, preferably to a range of 0.10 μm or more and 0.50 μm or less, and more preferably to a range of 0.20 μm or more and 0.50 μm or less, insulation failure due to ion migration can be reduced.

[0052] Furthermore, the Ni-containing layer 31 of the lead frame material 10 has an average KAM 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 0.50° to 2.00°. Here, if the average KAM value is less than 0.50°, strain in the Ni-containing layer 31 is reduced, making it easier for atoms constituting the base 2 to diffuse inside the Ni-containing layer 31. On the other hand, if the average KAM value is greater than 2.00°, excessive strain in the Ni-containing layer 31 occurs, reducing the adhesion of the Ni-containing layer 31 to the surface coating layer 32 (described later) and the solder wettability. Therefore, by setting the average KAM value in the Ni-containing layer 31 of the lead frame material 10 to 0.50° to 2.00°, strain in the Ni-containing layer 31 is appropriately increased, thereby reducing the diffusion of atoms constituting the base 2 into the Ni-containing layer 31 and improving the solder wettability.

[0053] Furthermore, the Ni-containing layer 31 of the lead frame material 10 has a mode of KAM of 0.4° or more in a cross section including the thickness direction t of the lead frame material 10, which is obtained by crystal orientation analysis using electron backscatter diffraction (EBSD). If the mode of KAM is less than 0.4°, the distribution of strain in the Ni-containing layer 31 becomes more uneven, making it easier for atoms constituting the base 2 to diffuse into the Ni-containing layer 31. Therefore, in the Ni-containing layer 31 of the lead frame material 10, by making the mode of KAM 0.4° or more, the distribution of strain in the Ni-containing layer 31 becomes approximately uniform, thereby reducing the diffusion of atoms constituting the base 2 into the Ni-containing layer 31.

[0054] 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.

[0055] 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 path along which atoms constituting the base 2 diffuse inside the Ni-containing layer 31 is lengthened, thereby further reducing the deposition of atoms constituting the base 2 on the surface of the lead frame material 10, making it possible to further reduce the occurrence of insulation defects due to ion migration. On the other hand, by making the thickness of the Ni-containing layer 31 5.0 μm or less, it is possible to make the lead frame material 10 less likely to crack when bent.

[0056] <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 of the Ni-containing layer 31 and the average and mode values ​​of the KAM, 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.

[0057] 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.

[0058] On the other hand, the heat treatment process may be performed in conjunction with forming a resin mold on the surface to secure and protect the semiconductor element. The heating temperature in the heat treatment process is preferably in the range of 100°C to 400°C. In general, when a lead frame material undergoes such a thermal history, the average crystal grain size of the Ni-containing layer 31 increases and the KAM value decreases, resulting in reduced heat resistance and solder wettability, making the material more susceptible to ion migration. In this regard, the lead frame material 10 of the present invention forms the Ni-plated layer 31 using the electroplated layer formation conditions described above in the coating process. This reduces strain within the Ni-containing layer 31 and suppresses diffusion of atoms constituting the substrate within the Ni-containing layer 31, even when heated in the heat treatment process. This allows the average crystal grain size and the average and mode KAM values ​​to be maintained within desired ranges.

[0059] 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.

[0060] 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.

[0061] In this way, by performing a heat treatment process on the material for electronic components 1 on which the Ni-containing layer 31 has been formed by performing multi-stage electroplating in the coating formation process, it is possible to obtain a lead frame material 10 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 the range of 0.10 μm to 0.60 μm, the average value of KAM in the cross section including the thickness direction t is in the range of 0.50° to 2.00°, and the mode of KAM in the cross section is 0.4° or more.

[0062] <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.

[0063] Furthermore, the electronic component material 1 of the present invention has high solder wettability even when heated as in the case of assembling a semiconductor package, and therefore can be preferably used for semiconductor packages equipped with such lead frames. Furthermore, even when used in an environment where dry and wet conditions alternate, the electronic component material 1 and lead frame material 10 of the present invention are unlikely to cause insulation failure within the semiconductor package due to ion migration of atoms constituting the base 2 and precipitation on the surface of the lead frame, and therefore can achieve high reliability, particularly in semiconductor packages for automotive applications.

[0064] 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]

[0065] Next, in order to further clarify the effects of the present invention, examples of the present invention and comparative examples will be described, but the present invention is not limited to these examples of the present invention.

[0066] <Pretreatment of the substrate> A conductive substrate 2 made of the metal or alloy of the type shown in Table 1 and having a thickness of 0.1 mm and a size of 50 mm length x 50 mm width was prepared by pressing, and was subjected to cathodic electrolytic degreasing and pickling as pretreatment.

[0067] Here, the cathodic electrolytic degreasing is carried out by heating an aqueous solution of sodium hydroxide with a concentration of 60 g / L as a degreasing solution in an electrolytic cell, immersing the substrate 2 in the degreasing solution heated to 60°C and connecting it to the anode of the electrolytic cell, and applying a current of 2.5 A / dm 2 The treatment was carried out by passing a current at a current density of 1000 kJ / cm for 60 seconds.

[0068] The pickling was carried out by immersing the substrate 2 after cathodic electrolytic degreasing in 10 mass % sulfuric acid at room temperature for 30 seconds.

[0069] <Formation of Ni-containing layer> Thereafter, a 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.

[0070] [Ni-Ge plating (when the "type of additive element" of the Ni-containing layer described in Table 1 is Ge)] For Examples 1 to 3 of the present invention, an aqueous solution containing nickel (Ni) metal at a concentration in the range of 100 g / L to 160 g / L of nickel sulfamate, 30 g / L of nickel chloride, 30 g / L of boric acid, and 1.0 g / L to 1.5 g / L of 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, the substrate 2 was connected to the cathode, an anode was arranged so as to face both surfaces of the substrate 2, and the Ni-containing layer 31 was formed by multi-stage electroplating in which energization and water washing in the plating electrolytic cell were repeated. Here, the multi-stage electroplating was carried out at a temperature of 50 °C and a current density of 10 A / dm 2 for 4 seconds in the plating electrolytic cell, and the step of taking out the substrate 2 from the plating electrolytic cell and washing it with water was repeated.

[0071] On the other hand, for Comparative Example 4, an aqueous solution containing nickel (Ni) metal at a concentration in the range of 100 g / L to 160 g / L of nickel sulfamate, 30 g / L of nickel chloride, 30 g / L of boric acid, and 1.0 g / L to 1.5 g / L of 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, the substrate 2 was connected to the cathode, an anode was arranged so as to face both surfaces of the substrate 2, and the Ni-containing layer 31 was formed by one-stage electroplating in which energization in the plating electrolytic cell was continuously carried out for 50 seconds at a temperature of 50 °C and a current density of 3 A / dm 2

[0072] [Ni-Mo plating (when the "type of additive element" of the Ni-containing layer described in Table 1 is Mo)] ​For Inventive Example 9, an aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration of 75 g / L to 115 g / L, 2 g / L to 10 g / L sodium molybdate, and 30 g / L boric acid was prepared as the electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic bath with an inner diameter of 80 mm. The substrate 2 was connected to the cathode, and anodes were placed facing both sides of the substrate 2. A multi-stage electroplating process was performed, which involved repeated application of current in the plating electrolytic bath and washing with water, to form a Ni-containing layer 31. The multi-stage electroplating was performed at a temperature of 50°C and a current of 10 A / dm 2 The steps of electroplating in the plating electrolytic bath at a current density of 1000 ppm for 4 seconds and removing the substrate 2 from the plating electrolytic bath and rinsing it with water were repeated.

[0073] On the other hand, for Comparative Example 2, an aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration of 75 g / L to 115 g / L, 0.8 g / L sodium molybdate, 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 substrate 2 was connected to the cathode. Anodes were placed facing both sides of the substrate 2. The electroplating was carried out at a temperature of 50°C and a current of 10 A / dm 2 The Ni-containing layer 31 was formed by one-stage electroplating in which current was continuously applied in a plating electrolytic bath at a current density of 1000 kJ / min for 20 seconds.

[0074] [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 sulfate with a nickel (Ni) metal concentration ranging from 75 g / L to 115 g / L, 30 g / L of boric acid, and 5 g / L to 10 g / L of zinc sulfate was prepared as the electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic bath with an inner diameter of 80 mm, and the substrate 2 was connected to the cathode. Anodes were placed facing both sides of the substrate 2. A Ni-containing layer 31 was formed by multi-stage electroplating, which involved repeated application of current in the plating electrolytic bath and washing with water. The multi-stage electroplating was carried out at a temperature of 50°C and a current of 10 A / dm 2The steps of electroplating in the plating electrolytic bath at a current density of 1000 ppm for 4 seconds and removing the substrate 2 from the plating electrolytic bath and rinsing it with water were repeated.

[0075] [Ni-Co plating (when the "type of added element" of the Ni-containing layer listed in Table 1 is Co)] For Inventive Examples 7 and 8, an aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration of 75 g / L to 115 g / L, 40 g / L to 60 g / L of cobalt sulfate, 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 bath with an inner diameter of 80 mm, and the substrate 2 was connected to the cathode. Anodes were placed facing both sides of the substrate 2. A multi-stage electroplating process was performed in which current was applied to the plating electrolytic bath and washing with water was repeated to form a Ni-containing layer 31. The multi-stage electroplating was performed at a temperature of 50°C and a current of 10 A / dm 2 The steps of electroplating in the plating electrolytic bath at a current density of 1000 ppm for 4 seconds and removing the substrate 2 from the plating electrolytic bath and rinsing it with water were repeated.

[0076] On the other hand, for Comparative Example 3, an aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration of 75 g / L to 115 g / L, 40 g / L to 60 g / L of cobalt sulfate, 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 substrate 2 was connected to the cathode. Anodes were placed facing both sides of the substrate 2. The electroplating was carried out at a temperature of 50°C and a current of 10 A / dm 2 The Ni-containing layer 31 was formed by one-stage electroplating in which current was continuously passed through the plating electrolytic bath at a current density of 1000 kJ / min for 25 seconds.

[0077] [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 of 75 g / L, 30 g / L boric acid, and 10 g / L sodium hypophosphite was prepared as the electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic bath with an inner diameter of 80 mm. The substrate 2 was connected to the cathode, and anodes were placed facing both sides of the substrate 2. A Ni-containing layer 31 was formed by multi-stage electroplating, which involved repeated application of current in the plating electrolytic bath and washing with water. Here, the multi-stage electroplating was performed at a temperature of 50°C and a current of 10 A / dm 2 The steps of electroplating in the plating electrolytic bath at a current density of 1000 ppm for 4 seconds and removing the substrate 2 from the plating electrolytic bath and rinsing it with water were repeated.

[0078] [Ni-Co-P plating (when the "type of added elements" of the Ni-containing layer listed in Table 1 is Co and P)] An aqueous solution containing nickel sulfate with a nickel (Ni) metal concentration of 75 g / L, 30 g / L nickel chloride, 30 g / L boric acid, 15 g / L cobalt sulfate, and 20 g / L sodium hypophosphite was prepared as an electroplating solution. 1 L of the electroplating solution was placed in a cylindrical plating electrolytic bath with an inner diameter of 80 mm. The substrate 2 was connected to the cathode, and anodes were placed facing both sides of the substrate 2. A multi-stage electroplating process was performed in which current was applied to the plating electrolytic bath and washing with water was repeated to form a Ni-containing layer 31. The multi-stage electroplating was performed at a temperature of 50°C and a current of 10 A / dm 2 The steps of electroplating in the plating electrolytic bath at a current density of 1000 ppm for 4 seconds and removing the substrate 2 from the plating electrolytic bath and rinsing it with water were repeated.

[0079] [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 115 g / L, 30 g / L nickel chloride, and 30 g / L 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 substrate 2 was connected to the cathode. Anodes were placed facing both sides of the substrate 2. A Ni-containing layer 31 was formed by multi-stage electroplating, which involved repeated application of current in the plating electrolytic cell and washing with water. The multi-stage electroplating was carried out at a temperature of 50°C and a current of 10 A / dm 2 The steps of electroplating in the plating electrolytic bath at a current density of 1000 ppm for 4 seconds and removing the substrate 2 from the plating electrolytic bath and rinsing it with water were repeated.

[0080] On the other hand, for Comparative Example 1, an aqueous solution containing nickel sulfamate with a nickel (Ni) metal concentration of 115 g / L, 30 g / L nickel chloride, and 30 g / L 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 substrate 2 was connected to the cathode. Anodes were placed facing both sides of the substrate 2. The electroplating was carried out at a temperature of 50°C and a current of 10 A / dm 2 The Ni-containing layer 31 was formed by one-stage electroplating in which current was continuously applied in a plating electrolytic bath at a current density of 1000 kJ / min for 20 seconds.

[0081] <Formation of surface coating layer> Next, for Inventive Examples 1 to 8, 10 to 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, 2, 4, 5, 7, 10, and 11, and Comparative Example 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 3, 6, 8, and 12, and Comparative Examples 2 and 3, 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 3 on the surface of the substrate 2 was performed, thereby obtaining materials for electronic components 1 for the Inventive Examples and Comparative Examples.

[0082] [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.

[0083] [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 2By 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.

[0084] [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.

[0085] [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, 100 g / L citric acid, and 20 g / L dipotassium hydrogen phosphate 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.

[0086] <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.

[0087] <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.

[0088] [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)

[0089] [2] Measurement of the average and mode values ​​of KAM in the Ni-containing layer The average and mode KAM values ​​for 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.), with a magnification of 30,000x and measurement intervals of 50 nm or less. Measurement points with a reliability index (CI) value of 0.1 or less were excluded from the analysis. The average KAM value for each measurement area was calculated by considering boundaries with a misorientation 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 KAM value for each measurement region was calculated from the average KAM value for the five measurement regions to calculate the average KAM value for the Ni-containing layer 31 for each of the electronic component material 1 and the lead frame material 10. Furthermore, the KAM values ​​for all measurement points to be analyzed within these five measurement regions were rounded to the nearest tenth, and a frequency distribution was obtained in 0.1° increments to determine the mode of the KAM in this frequency distribution. The results are shown in Table 1.

[0090] [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 (product 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. Isopropyl alcohol containing 25% by mass of rosin was used as the flux. Among the examples and comparative examples of the present invention, for those having a surface coating layer 32, the solder wettability of the surface of the surface coating layer 32 was evaluated.

[0091] 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 solder wettability was evaluated as excellent and marked with a "◎". When the measured zero cross time was more than 2.0 seconds and less than 10.0 seconds, the solder wettability was evaluated as good and marked with a "○". On the other hand, when the measured zero cross time was more than 10.0 seconds, the solder wettability was evaluated as poor and marked with a "×". The results are shown in Table 2.

[0092] [4] Evaluation of ion migration resistance Two lead frame materials 10, each 50 mm long and 40 mm wide, were used as test materials. As shown in Figure 3(a), the two lead frame materials 10a and 10b were arranged side by side with a 1.0 mm gap d between them, with their edges facing each other, and these were fixed to the surface of a resin plate 5 with screws to form a test piece 4. Next, a droplet P of a 20 ppm NaCl aqueous solution was placed across two of the lead frame materials 10a and 10b of the test piece 4 for 5 minutes, and then the droplet P was allowed to dry for 15 minutes. This cycle was repeated 18 times over a total of 6 hours, and the two lead frame materials 10a and 10b were then connected to the electrical circuit shown in Figure 3(b) using wiring 6a and 6b, and the maximum value of the leakage current flowing between the two lead frame materials 10a and 10b was measured. Here, droplets P of an NaCl aqueous solution were placed at a position spanning the lead frame materials 10a and 10b of the specimen 4, and then a cycle of drying the droplets P of the NaCl aqueous solution was carried out to evaluate the resistance to ion migration in a harsh environment where salt as well as moisture adheres to the surfaces of the lead frame materials 10a and 10b, in an environment where dry and wet cycles occur repeatedly, simulating a seaside environment such as an offshore wind power generation plant.

[0093] When the measured leakage current was 0.20 A or less, even when used in a dry-wet cycle environment, insulation failure due to ion migration of the atoms constituting the base was unlikely to occur, and the ion migration resistance was evaluated as "◎". Furthermore, when the measured leakage current was greater than 0.20 A but less than 0.25 A, even when used in a dry-wet cycle environment, insulation failure due to ion migration of the atoms constituting the base was unlikely to occur, and the ion migration resistance was evaluated as "○". On the other hand, when the measured leakage current exceeded 0.25 A, insulation failure due to ion migration of the atoms constituting the base occurred when used in a dry-wet cycle environment, and the ion migration resistance was evaluated as "×". The results are shown in Table 2.

[0094] [5] Overall rating Of these evaluation results, for the three evaluation results regarding the solder wettability of the electronic component material, the solder wettability of the lead frame material, and ion migration resistance, if all three were rated "◎," the electronic component material had excellent solder wettability even when heated to around 400°C, simulating the assembly of semiconductor packages, and had excellent ion migration resistance even in an environment where dryness and humidity cycles occur. Furthermore, if all three of these evaluation results were rated "◎" or "○" (excluding cases where all three were rated "◎"), the electronic component material had good or excellent solder wettability even when heated to around 400°C, simulating the assembly of semiconductor packages, and had good or excellent ion migration resistance even when used in an environment where dryness and humidity cycles occur, and was rated "○." On the other hand, if at least one of these three evaluation results was "X," it was evaluated as "X" because the solder wettability was poor at least either before or after heating, which is assumed to occur during semiconductor package assembly, or the ion migration resistance was poor when placed in an environment where dry and wet cycles occur. The results are shown in Table 2.

[0095] [Table 1]

[0096] [Table 2]

[0097] From the results in Table 1, the average crystal grain size of the Ni-containing layer 31 when viewed in a cross section including the thickness direction t, and the average and mode values ​​of KAM in this cross section, were all within the appropriate ranges of the present invention for the electronic component materials and lead frame materials of Examples 1 to 12. In this case, the electronic component materials and lead frame materials of Examples 1 to 12 were evaluated as either "◎" or "◯" in the three evaluation results regarding the solder wettability of the electronic component material, the solder wettability of the lead frame material, and ion migration resistance.

[0098] In contrast, the electrical contact material of Comparative Example 1, in which the Ni-containing layer 31 was formed by one-stage electroplating in which current was continuously passed through a plating electrolytic bath, had an average value and a mode of KAM in a cross section including the thickness direction t that were smaller than the appropriate range of the present invention, and the three evaluation results regarding the solder wettability of the electrical contact material, the solder wettability of the lead frame material, and the ion migration resistance were all evaluated as "X."

[0099] In addition, the electrical contact material of Comparative Example 2, in which the content of sodium molybdate in the electroplating solution used to form the Ni-containing layer 31 was low and the Ni-containing layer 31 was formed by one-stage electroplating, had an average value and a mode of KAM in a cross section including the thickness direction t that were smaller than the appropriate range of the present invention, and both of the evaluation results regarding the solder wettability and ion migration resistance of the lead frame material were evaluated as "X".

[0100] In addition, the electrical contact material of Comparative Example 3, in which the Ni-containing layer 31 was formed by one-stage electroplating in which current was continuously passed through a plating electrolytic bath, 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 the solder wettability and ion migration resistance of the lead frame material were evaluated as ``X''.

[0101] In addition, the electrical contact material of Comparative Example 4, in which the current density when forming the Ni-containing layer 31 was small and the Ni-containing layer 31 was formed by one-stage electroplating, 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 the average value and mode of KAM in the cross section including the thickness direction t were smaller than the appropriate range of the present invention, and the two evaluation results regarding the solder wettability and ion migration resistance of the lead frame material were both evaluated as ``X.''

[0102] Therefore, it was revealed that the electronic component material 1 and lead frame material 10 of Examples 1 to 12 of the present invention have high solder wettability even when heated as in the case of assembling a semiconductor package, and are less likely to cause insulation defects due to ion migration, in which atoms constituting the base material precipitate on the surface of the lead frame, even when used in an environment where dry and wet conditions occur repeatedly. [Explanation of symbols]

[0103] 1. 1A Materials for electronic components 10, 10A, 10a, 10b lead frame material 2 Base 21 Surface of the substrate 3, 3A surface coating 31 Ni-containing layer 32 Surface coating layer 32a 1st surface coating layer 32b Second surface coating layer 4 Specimen 5 Resin board 6a, 6b wiring d Interval at which test pieces are placed t Thickness direction of electronic component material (or lead frame material) P NaCl aqueous solution droplets

Claims

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, 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, A material for electronic components, wherein an average value of KAM in the cross section obtained by crystal orientation analysis using an electron backscatter diffraction (EBSD) method is in the range of 0.60° or more and 2.00° or less, and a mode value of KAM in the cross section is 0.5° or more.

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. A method for producing a material for electronic components according to any one of claims 1 to 5, comprising: A method for producing a material for electronic components, comprising a coating formation step of forming the surface coating on at least a part of the surface of the substrate by electroplating.

7. 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 value of KAM in the cross section obtained by crystal orientation analysis using electron backscatter diffraction (EBSD) is in the range of 0.50° or more and 2.00° or less, and the most frequent value of KAM in the cross section is 0.4° or more.

8. 8. A method for manufacturing a lead frame material according to claim 7, 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:

9. A semiconductor package having a lead frame formed using the lead frame material according to claim 7.

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