JP2017197788A - Manufacturing method of electronic component contact member and electronic component contact member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost manufacturing method of electronic component contact member capable of providing good wire bonding reliability even when making a gold plated coated film thinner than conventional ones and providing good solder connection reliability by making the gold plated coated film thin in an electronic member by forming a gold plated coated film after molding a ground nickel coated film by an electrolytic nickel plating method, or an electrolytic nickel plating liquid capable of being used for forming a ground nickel plated coated film in the electronic component contact member.SOLUTION: A ground nickel plated coated film is formed so that a crystal surface exhibiting maximum peak intensity in an X ray diffraction is a (200) surface. Especially a ground nickel plated coated film is formed by using an electrolytic nickel plating liquid containing an aliphatic organic compound having 2 hydroxyl groups in a molecule, no sulfur in the molecule and 2 to 10 carbon atoms.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing an electronic component contact member such as a printed circuit board or a lead frame, and in particular, by controlling the crystal orientation of the underlying electrolytic nickel film, the gold plating film (or gold alloy plating film) is thin. The present invention also relates to a method of manufacturing an electronic component contact member capable of obtaining good wire bonding reliability (hereinafter sometimes referred to as “wire bonding property” or “bonding property”).
The present invention can also be used to form a gold alloy plating film that can be used to manufacture such an electronic component contact member, and to form a base nickel plating film on such an electronic component contact member. It relates to an electrolytic nickel plating solution.

Conventionally, copper or a copper alloy having excellent electrical conductivity is used as an electronic component contact member necessary for wire bonding connection between a semiconductor and a printed board. In general, a base nickel plating film is formed on copper or a copper alloy, and a gold plating film or a gold alloy plating film is formed on the base nickel plating film.
A printed circuit board (semiconductor package substrate) connected to a semiconductor by wire bonding is connected to a motherboard substrate by solder balls, and in a lead frame, a solder fillet is formed on an outer lead portion and mounted on the motherboard substrate. In many cases, solder ball bondability (hereinafter sometimes referred to as “solder bondability”) is also required. The wire bonding reliability increases as the gold plating film thickness increases, and the connection reliability increases. As the solder bonding property increases, the strength decreases as the gold-tin alloy layer is formed, so electrolytic nickel plating / electrolytic gold (or In a semiconductor package printed board manufactured by (gold alloy) plating, the gold plating film thickness is generally set to about 0.3 to 0.6 μm.

  As the price of precious metals has soared in recent years, the number of cases where contact members that reduce the thickness of gold (or gold alloy) plating films (savings) are required is increasing, and gold (or gold alloy) plating films have been made thinner. In particular, it is an important issue to obtain a nickel plating / gold (or gold alloy) plating electronic component contact member having excellent wire bonding reliability.

  Even if the gold (or gold alloy) plating film is thinned, various methods have been studied as a method for producing an electronic component contact member having excellent wire bonding reliability, and the idea is as follows (i) to ( iv).

(I) A palladium layer is formed as an intermediate layer to reduce pinholes in the gold (or gold alloy) plating film (Patent Document 1, etc.).
(Ii) The surface roughness of the contact terminals is reduced (Patent Document 2 etc.).
(Iii) The base nickel plating film is made multilayer (Patent Document 3 etc.).
(Iv) The crystal grain size of the underlying nickel plating film is largely controlled (Patent Document 4 etc.).

  Patent Document 1 discloses that a palladium plating layer is formed as an intermediate layer between a base nickel plating film and a gold plating film in order to avoid a decrease in wire bonding strength due to nickel diffusion through pinholes in the gold plating film. Is described. However, if an expensive palladium layer is provided as the intermediate layer, the production cost increases.

  Patent Document 2 describes that sufficient wire bonding reliability can be obtained by adjusting the surface roughness of the wire bonding terminal to 0.1 to 8 μm. However, as a result of studies by the present inventors, it has been found that when the electrolytic gold plating film is thinned, sufficient wire bonding reliability cannot be obtained simply by smoothing the surface.

Patent Document 3 discloses a gold / nickel / nickel three-layer plated copper alloy electronic component and a method for manufacturing the same as an electronic component having a good wire bonding property even if the gold plating is thinned. In Patent Document 3, an electrolytic nickel plating film with a high sulfur content is formed in the lower layer to smooth the surface, and a matte nickel plating film with a low sulfur content is formed in the intermediate layer with a thickness that does not impair the smoothness. Accordingly, there is a description that the gold plating film can be thinned because the sulfur of impurities is suppressed from diffusing to the upper gold surface due to thermal diffusion during mounting.
However, in an actual manufacturing site, two electrolytic nickel plating tanks are required. The nickel plating brightener in the first tank (for the lower layer) is gradually brought into the second tank (for the intermediate layer), so that the intermediate layer is formed. There was a problem that the matte nickel plating film may not be obtained or the management becomes complicated.

  Patent Document 4 discloses a substrate excellent in connection reliability of a bonding portion and a manufacturing method thereof. In Patent Document 4, there is a description that wire bonding reliability is improved by setting the average value of the crystal size of nickel in the nickel plating layer to 2 μm or more. Only a standard thickness of about 0.5 μm is evaluated. Moreover, although the composition of the electrolytic nickel plating bath to which the brightener is added is described in the examples, the specific compound name of the brightener component is unknown, and the nickel crystal size evaluation method is also specific. No photos are attached, and it is not considered at all whether the gold plating film is effective.

  The need to manufacture electronic component contact members that can maintain good wire bonding reliability, etc. while keeping costs down is increasing, but with such known technologies, either cost or reliability is required. Insufficient, there was room for further improvement.

JP 2006-196648 A JP-A 63-256498 JP-A-10-251860 JP 2002-016100 A

  The present invention has been made in view of the above-described background art, and the problem is that an electronic component in which a gold plating film is formed after forming a base nickel film by an electrolytic nickel plating method is conventionally used. Compared with the case where it is thinner, good wire bonding reliability can be obtained, and by making the gold plating film thinner, good solder connection reliability can be obtained. Another object of the present invention is to provide an electrolytic nickel plating solution that can be used to form a base nickel plating film on such an electronic component contact member.

  As a result of intensive studies to solve the above problems, the present inventor has found that when the gold plating film is thin, the wire bonding property is remarkably deteriorated depending on the crystal orientation of the underlying nickel plating film. Thus, when the specific crystal plane ratio of the underlying nickel plating film was increased, it was surprisingly found that excellent wire bonding properties can be obtained even if the gold plating film is thinned. As a result of developing ideas based on these findings, the present invention has been completed.

  That is, in the present invention, a base nickel plating film is formed on a copper or copper alloy substrate by an electrolytic plating method using an electrolytic nickel plating solution, and then a gold plating film or a gold alloy plating is formed on the base nickel plating film. An electronic component contact member manufacturing method for forming a film, wherein the underlying nickel plating film has a (200) plane as the crystal plane showing the maximum peak intensity of X-ray diffraction. A method for manufacturing a contact member is provided.

Further, the present invention is a method for producing a gold plating film or a gold alloy plating film for use in the method for producing the electronic component contact member described above,
A gold plating film or a gold alloy plating film having an average thickness of 0.05 to 0.3 μm is formed on a nickel plating film whose crystal plane showing the maximum peak intensity of X-ray diffraction is a (200) plane. A method for producing a gold plating film or a gold alloy plating film is provided.

Further, the present invention provides an electronic component contact in which a base nickel plating film is formed on a copper or copper alloy substrate, and a gold plating film or a gold alloy plating film is formed on the base nickel plating film A member,
In the base nickel plating film, the crystal plane showing the maximum peak intensity of X-ray diffraction is the (200) plane, and the (200) plane, (111) plane, (220) plane, (311) plane, (222) plane And X-ray diffraction peak intensities corresponding to the (400) plane are I (200), I (111), I (220), I (311), I (222) and I (400), respectively. The present invention provides an electronic component contact member characterized by satisfying all of the following relationships (a) to (d).
(A) I (111) / I (200) ≦ 0.3
(B) I (220) / I (200) ≦ 0.05
(C) I (311) / I (200) ≦ 0.05
(D) I (200) / [I (200) + I (111) + I (220) + I (311) + I (222) + I (400)] ≧ 0.7

  The present invention also provides an electrolytic nickel plating solution for forming a base nickel plating film in the method of manufacturing an electronic component contact member.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic component contact member excellent in wire bonding reliability can be obtained. In particular, when the gold plating film is thin, the wire bonding reliability tends to be insufficient in the prior art, but in the present invention, sufficient wire bonding reliability is obtained even when the gold plating film is thin. be able to.

  In the present invention, since there is no need for an intermediate layer using expensive palladium or a base nickel plating layer to be multilayered, the gold plating film can be made thinner than conventional products by a low-cost manufacturing method. .

  In addition, since the gold plating film thickness can be reduced in the present invention, not only is it advantageous in terms of cost, but also when soldering, it is possible to prevent a decrease in strength due to the formation of a gold-tin alloy layer, and solderability is also improved. improves.

It is a schematic diagram which shows the printed circuit board for evaluation used by each evaluation example. It is a schematic diagram which shows the wire bonding terminal part of the printed circuit board for evaluation used in each evaluation example. It is a figure for demonstrating the evaluation method (cutting / peeling location) in the wire pull test of each evaluation example. It is a graph which shows the X-ray-diffraction pattern (raw data) of the nickel plating film obtained in the evaluation example 10. 10 is a graph showing the peak intensity of the crystal plane of the nickel plating film obtained in Evaluation Example 10.

  Hereinafter, the present invention will be described. However, the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented.

  In the method of manufacturing an electronic component contact member of the present invention, a base nickel plating film is formed on a copper or copper alloy substrate by an electrolytic plating method using an electrolytic nickel plating solution, and then a gold is formed on the base nickel plating film. A plating film or a gold alloy plating film is formed. In the base nickel plating film, the crystal plane showing the maximum peak intensity of X-ray diffraction is the (200) plane.

<Copper or copper alloy substrate>
As a copper or copper alloy base material, there is no limitation in particular in thickness and a manufacturing method, A well-known thing can be used.
For example, a plate material, a rolled foil, an electrolytic plating film, an electroless plating film, a dry film such as sputtering or vapor deposition, and the like can be given.
In the copper alloy, other alloy types of copper include nickel, chromium, zinc, tin, iron, beryllium and the like.

<Base nickel plating film>
In the present invention, a base nickel plating film is formed on a copper or copper alloy substrate by an electrolytic plating method using an electrolytic nickel plating solution. At this time, when the crystal plane of the underlying nickel plating film is expressed by the Miller index (hkl), the crystal plane showing the maximum peak intensity of X-ray diffraction (hereinafter sometimes referred to as “maximum intensity plane”). Is the (200) plane.

The crystal orientation of the underlying nickel plating film can be analyzed by, for example, the X-ray diffraction apparatus described in the examples described later. The (200) plane, (111) plane, and (220) plane are the crystal planes of nickel. X-ray diffraction patterns corresponding to the (311) plane, (222) plane, and (400) plane are obtained. The background is removed from the X-ray diffraction pattern by analysis software to obtain a diffraction peak. In the obtained diffraction peaks, the peak intensities (Counts) corresponding to the (200) plane, the (111) plane, the (220) plane, the (311) plane, the (222) plane, and the (400) plane are respectively represented by I (200 ), I (111), I (220), I (311), I (222), and I (400).
In the present invention, the base nickel plating is performed so that I (200) is maximized among I (200), I (111), I (220), I (311), I (222), and I (400). Form a film.

In the present invention, the base nickel plating film preferably satisfies all the following relationships (a), (b) and (c) in addition to the (200) plane being the maximum strength plane.
(A) I (111) / I (200) ≦ 0.3
(B) I (220) / I (200) ≦ 0.05
(C) I (311) / I (200) ≦ 0.05

In the present invention, it is particularly preferable that the base nickel plating film further satisfies the following relationship (d).
(D) I (200) / [I (200) + I (111) + I (220) + I (311) + I (222) + I (400)] ≧ 0.7

That is, the peak intensity of the (200) plane is more preferable as compared with the peak intensity of other crystal planes, because the effect of the present invention is exhibited.
Hereinafter, “the (200) surface of the underlying nickel plating film is the maximum strength surface”, in addition to satisfying the relationships (a) to (c), and in addition to satisfying the relationship (d) This is described as “(200) plane orientation is strong”.

  In addition, in the wet plating method using a plating solution, there is a tendency that a plating film can be produced uniformly, and the difference in crystal orientation of the nickel plating film depending on the part on the copper or copper alloy base material to be plated It is thought that there is almost no.

  When a gold plating film is formed on a base nickel plating film having a strong (200) plane orientation, nickel can be prevented from diffusing into the gold plating film after heating by wire bonding. Even when the plating film is thin, the wire bonding property is good.

  The crystal orientation of the underlying nickel plating film depends on conditions such as the composition of the electrolytic nickel plating solution used, the type of copper or copper alloy substrate, the pattern of the substrate, the temperature at which the underlying nickel plating is performed, etc. According to the inventor's study, the composition of the electrolytic nickel plating solution (particularly, a component added in a small amount) tends to make the (200) plane orientation of the underlying nickel plating film easily (or hardly become strong). It was found.

  In addition, the electrolytic nickel plating solution is an aliphatic organic compound having 2 to 10 carbon atoms that has two hydroxyl groups in the molecule and no sulfur in the molecule (hereinafter referred to as “specific aliphatic organic compound”). In the case of containing a base nickel plating film to be formed, the (200) plane orientation tends to be strong.

Specific examples of the specific aliphatic organic compound include butanediol, butenediol, butynediol, hexanediol, hexenediol, hexynediol, dimethylhexanediol, dimethylhexenediol, dimethylhexynediol, and butanediol ethoxy. Rate, butenediol ethoxylate, butynediol ethoxylate, dimethyloctanediol, dimethyloctenediol, dimethyloctynediol, hexadiynediol, dioxanediol, 1,3-dihydroxyacetone dimer, dichlorobutanediol, dichlorobutenediol, dichlorobutynediol , Dibromobutanediol, dibromobutenediol and dibromobutynediol are preferred.
These may be used alone or in combination of two or more.

  Moreover, when the compound represented by the following general formula (1) is used among the specific aliphatic organic compounds, the (200) plane orientation of the base nickel plating film is likely to become stronger.

[In General Formula (1), X is a bivalent coupling group which consists of a carbon atom and / or an oxygen atom, and has a double bond or a triple bond. ]

  The compound represented by the general formula (1) may be used alone or in combination of two or more.

The total content of the compound represented by the general formula (1) in the electrolytic nickel plating solution is preferably 0.01 g / L or more, more preferably 0.03 g / L or more, and particularly preferably 0.05 g / L or more. preferable. Moreover, 0.4 g / L or less is preferable, 0.3 g / L or less is more preferable, and 0.2 g / L or less is especially preferable.
Within the above range, the (200) plane orientation of the underlying nickel plating film tends to be strong.

It is preferable that the electrolytic nickel plating solution does not contain a sulfur-containing compound (excluding compounds in which all sulfur atoms are hexavalent).
Divalent or tetravalent sulfur is easily reduced when electrolytic nickel plating is applied. Therefore, when electrolytic nickel plating is performed using a compound containing bivalent or tetravalent sulfur, Sulfur tends to co-deposit. Since the eutectoid of sulfur may cause the maximum strength surface of the underlying nickel plating film to be other than the (200) surface, or the strength of the (200) surface may be lowered ((200) surface orientation is It is not preferable that the electrolytic nickel plating solution contains a compound containing divalent or tetravalent sulfur.

On the other hand, in the case of a small amount of a sulfur-containing compound in which all sulfur atoms are hexavalent, sulfur does not easily co-deposit in the base nickel plating film, and does not significantly affect the crystal orientation of the base nickel plating film. Although it may be contained in the nickel plating solution, if it is contained in a large amount, the action of the specific aliphatic organic compound may be inhibited.
The total content of sulfur-containing compounds in which all the sulfur atoms are hexavalent is preferably 0.5 times or less in terms of molar ratio with respect to the total content of the specific aliphatic organic compound, and 0.2 times It is particularly preferred that

A compound having a hexavalent sulfur atom includes a sulfamate ion (NH ₃ ⁺ SO ₃ ⁻ ), a sulfate ion (SO ₄ ²⁻ ), a hydrogen sulfate ion (HSO ₄ ⁻ ), a sulfonate ion (—SO ² ) in the molecule. ₃ ^-), sulfone group _(-SO 3 H), a sulfonyl group (-S (= _{O) 2} - compound with, etc.).
These compounds are often useful when contained in an electrolytic nickel plating solution, and often do not significantly affect the crystal orientation of the underlying nickel plating film, so are contained in the electrolytic nickel plating solution of the present invention. May be.

  Examples of the compound having a hexavalent sulfur atom include, but are not limited to, sulfamic acid, sulfuric acid, alkyl sulfuric acid, alkyl sulfonic acid, aromatic sulfonic acid, aromatic sulfonimide, aromatic sulfonamide, and salts thereof. Can be mentioned.

  About sulfamic acid and a sulfuric acid, it can be contained for pH adjustment of a nickel salt or an electrolytic nickel plating solution.

  Salts such as sodium sulfamate, sodium sulfate, potassium sulfamate, potassium sulfate, ammonium sulfamate, ammonium sulfate, lithium sulfamate, lithium sulfate, magnesium sulfamate, magnesium sulfate should be included in the electrolytic nickel plating solution as an electrically conductive component. Can do.

Aromatic sulfonic acids such as benzene sulfonic acid; benzene sulfonimide sodium (saccharin sodium), aromatic sulphonimides such as dibenzene sulphonimide, aromatic sulphonamides such as benzene sulphonamide, etc. In order to improve the appearance of the electrolytic nickel plating film, it may be contained in the electrolytic nickel plating solution as a so-called primary brightener component.
However, these need to be contained to the extent that the effects of the present invention are not impaired. That is, (200) plane orientation should not be inhibited by including these primary brightener components.

The electrolytic nickel plating solution of the present invention preferably contains one or more compounds selected from the group consisting of nickel sulfamate, nickel sulfate, nickel chloride, nickel bromide and nickel carbonate as a nickel source.
Since these nickel compounds have sufficient water solubility, a sufficient amount of nickel ions can be supplied to the electrolytic nickel plating solution. Moreover, by using these nickel compounds as a nickel source, the (200) plane orientation of the underlying nickel plating film tends to be strong.

The total content of these nickel compounds in the electrolytic nickel plating solution is preferably 50 g / L or more, more preferably 100 g / L or more, and particularly preferably 200 g / L or more. Moreover, 1000 g / L or less is preferable, 700 g / L or less is more preferable, and 500 g / L or less is especially preferable.
When it is within the above range, the plating rate becomes sufficient, and the (200) plane orientation of the underlying nickel plating film tends to become strong.

The electrolytic nickel plating solution preferably contains a pH buffer. As specific examples of pH buffering agents, it is particularly preferable to add boric acid, metaboric acid, acetic acid, tartaric acid, citric acid, and salts thereof. These may be used alone or in combination of two or more. You may mix and use.
By using these buffering agents, the (200) plane orientation of the underlying nickel plating film tends to be strong.

  In order to improve the wettability to the contact member, the electrolytic nickel plating solution of the present invention may contain a surfactant or a wetting agent as necessary. As the surfactant, those which do not inhibit the orientation of the (200) plane are preferable.

Examples of the surfactant include nonionic surfactants, anionic surfactants, amphoteric surfactants, and cationic surfactants.
Of these, anionic surfactants are preferred.
Nonionic surfactants, cationic surfactants, and amphoteric surfactants are not preferred because they often have a large effect on the orientation of the underlying nickel.
Moreover, when a surfactant contains a sulfur atom, it is preferable that all the sulfur atoms are hexavalent so as not to inhibit the (200) plane orientation.

  Examples of the anionic surfactant include carboxylic acid type, sulfonate type, sulfate ester type, phosphate ester type, etc., but sulfonate type and sulfate type anion type having a hexavalent sulfur atom. A surfactant is preferred. Specifically, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium dioctylsulfosuccinate, and dimethylsodium sulfoisophthalate are particularly preferable.

  The base nickel plating film is preferably formed so as to have an average thickness of 1 μm or more, particularly preferably 2 μm or more. Moreover, it is preferable to form so that an average thickness may be 10 micrometers or less, and it is especially preferable to form so that it may become 8 micrometers or less.

The temperature at which the base nickel plating film is formed is preferably 30 ° C. or higher, and particularly preferably 40 ° C. or higher. Moreover, 70 degrees C or less is preferable and 60 degrees C or less is especially preferable.
Within the above range, the (200) plane orientation of the underlying nickel plating film tends to be strong. Moreover, it becomes easy to make the average thickness of a base nickel plating film into the said range.

The current density when forming the base nickel plating film is preferably 0.5 A / dm ² or more, particularly preferably 1 A / dm ² or more. Moreover, 10 A / dm ² or less is preferable and 5 A / dm ² or less is particularly preferable.
Within the above range, the (200) plane orientation of the underlying nickel plating film tends to be strong. Moreover, it becomes easy to make the average thickness of a base nickel plating film into the said range.

The time for forming the base nickel plating film is preferably 0.5 minutes or more, particularly preferably 1 minute or more. Moreover, 100 minutes or less are preferable and 50 minutes or less are especially preferable.
Within the above range, the (200) plane orientation of the underlying nickel plating film tends to be strong. Moreover, it becomes easy to make the average thickness of a base nickel plating film into the said range.

<Gold plating film or gold alloy plating film>
A method for forming a gold plating film or a gold alloy plating film on the underlying nickel plating film is not particularly limited, and a known method such as an electrolytic plating method or an electroless plating method can be used.
The electroplating method using an external power source is particularly preferable because the plating time can be shortened, the bath life can be increased, and the cost is advantageous.

  The type of electrolytic gold or gold alloy plating solution for forming a gold plating film or a gold alloy plating film by the electrolytic plating method is not particularly limited, but a bath using gold cyanide salt or a bath using gold sulfite salt. And a bath using a gold cyanide salt, which is inexpensive in producing gold salt, is particularly preferred.

  Moreover, there is no limitation in particular of the alloy element kind of gold alloy plating, Nickel, cobalt, silver, palladium etc. are mentioned, Silver, palladium etc. are especially preferable.

The average thickness of the gold plating film or the gold alloy plating film is preferably 0.05 to 0.3 μm, particularly preferably 0.07 to 0.2 μm.
If the average thickness is too thin, sufficient wire bonding reliability may not be obtained. If the average thickness is too thick, the solder joint strength may be reduced, and the cost is disadvantageous. .
The average thickness of the gold plating film or the gold alloy plating film preferable in the present invention is the average thickness (0 of gold (or gold alloy) plating film used in a general semiconductor package printed board to be joined by wire bonding. .3 to 0.6 μm). By using the method of the present invention, the cost of gold can be suppressed.

[Action / Principle]
It is known that the average thickness of the gold (or gold alloy) plating film can be reduced by reducing the surface roughness of the underlying nickel plating film, but by making the surface of the underlying nickel plating film a specific crystal plane, It is not known that the average thickness of the gold (or gold alloy) plating film can be reduced.
Although the present invention is not limited to the following, in the present invention, the surface of the underlying nickel plating film is made to have a specific crystal surface, so that the gold (or gold alloy) plating film on which nickel is present. It is considered that the inside is suppressed from appearing on the surface of the gold (or gold alloy) plating film.

At the time of wire bonding, for example, the base nickel plating film and the gold (or gold alloy) plating film are heated to 180 ° C. to 200 ° C., and diffusion of nickel or the like is promoted.
If even a very small amount of nickel oxide or the like is present on the surface of the gold (or gold alloy) plating film, the wire bonding property is considered to deteriorate.
Although not limited, in the present invention, due to the orientation of a specific crystal plane, even after heating in the wire bonding process, even if the gold plating film is thin, the nickel (or gold alloy) plating film has a surface of nickel (or gold alloy). It is presumed that the wire bonding property was kept good because the (oxide) did not exist by diffusion (does not come out).

  Further, in the present invention, by adding a specific aliphatic organic compound to the electrolytic nickel plating solution for forming the underlying nickel plating film, the (200) plane orientation of the formed electrolytic nickel plating film is strengthened. Although details are not clear, the following can be considered. However, the present invention is not limited to the scope of the following effects.

That is, the specific aliphatic organic compound suppresses the anisotropic growth of the nickel plating film by repeating equilibrium adsorption and desorption on a crystal plane other than the (200) plane of nickel, and preferentially orients it on the (200) plane. It is assumed that it can be done.
And if an electrolytic gold plating film is formed on a nickel film preferentially oriented on the (200) plane, diffusion of nickel into the gold plating film due to heating can be prevented. As a result, even if the gold plating film is thin It is presumed that the wire bonding property is improved.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples and comparative examples as long as the gist thereof is not exceeded.

Evaluation Examples 1 to 22
As a base material, a 30 μm thick copper wiring (rolled copper foil 18 μm, electrolytic copper sulfate plating 12 μm) is formed on a BT (Bismaleimide Triazine) material, and a wire bonding terminal portion 2 and a gate portion 3 for molding resin sealing process on the surface. An evaluation printed circuit board (manufactured by Nippon Pure Chemical Co., Ltd.) 1 having a ball terminal portion (ball grid array pattern) 4 opened with a solder resist on the back surface was used (FIG. 1).
The size of the evaluation printed circuit board 1 is 48 mm × 44 mm × 0.26 mmt. In the wire bonding terminal portion 2, 30 wire bonding terminals 2a (0.1 mm × 0.2 mm) were arranged in parallel at intervals of 0.1 mm (FIG. 2). The size of the gate portion 3 was 4.5 mm × 38 mm, and the size of each ball terminal portion 4 was φ0.40 mm.

  On the evaluation printed circuit board, a film having an average of 8 μm was formed by electrolytic nickel plating by the process described in Table 1, and an average film having a thickness of 0.1 μm was formed thereon by cyan electrolytic gold plating. Washing was included between each step.

<Crystal orientation of nickel plating film>
The gate part 3 of the obtained electrolytic nickel plating / electrolytic gold plating substrate was cut out with scissors and immersed in a gold release agent (stripper gold, manufactured by Nippon Kosei Kagaku Co., Ltd.) for 1 minute at room temperature to release the gold plating film. The crystal orientation of the nickel plating of the gate portion 3 was measured with an X-ray diffraction analyzer (XRD-6100, manufactured by Shimadzu Corporation). Table 2 shows the measurement conditions.

X-ray diffraction pattern after measurement (in the case of evaluation Example 10 shown in FIG. 4.) After the smoothing process to remove the background, followed by removal of intensity from CuKa _2-wire, obtain an X-ray diffraction peak pattern It was. The obtained peak pattern was compared with an ICDD JCPDS card (No. 00-004-0850), and the crystal plane of the nickel plating film was assigned. The case of Evaluation Example 10 is shown in FIG.
Here, the crystal plane of the nickel plating film used for the evaluation of the crystal orientation is expressed by the Miller index (hkl), and the (111) plane, (200) plane, (220) plane, (311) plane, (222) Plane, (400) plane. From the peak intensity I (hkl) (unit: Counts) of each crystal plane, the ratio of the peak intensity of each crystal plane to the (200) plane I (hkl) / I (200) and the total peak intensity of each crystal plane The ratio of peak intensity I (200) / I [total] on the (200) plane was calculated. Table 3 shows the data processing conditions.

<Surface roughness>
The surface roughness of the wire bonding terminal 2a (0.1 mm × 0.2 mm) after plating was measured. A three-dimensional non-contact surface shape measurement system (Micromap MM527ME-M100 type, manufactured by Ryoka System Co., Ltd.) was used as the measurement apparatus. The three-dimensional surface roughness (Sa) defined by summing and averaging the absolute values of deviations from the average line to the measurement curve was defined as “surface roughness”.

<Wire bonding property>
The evaluation printed circuit board 1 after plating was subjected to heat treatment at 180 ° C. for 15 hours. After the heat treatment, a gold wire having a diameter of 25 μm was bonded to the wire bonding terminal 2a. As shown in FIG. 2, wire bonding was performed by ball-wedge bonding. A ball bond 2c is formed near the center of an arbitrary first terminal, and a wedge bond 2d is formed on the second terminal to form a wire loop 2b of about 0.8 mm.
Table 4 shows the bonding conditions.

Bonding was performed with N = 40, and the case where the wire loop 2b could be formed was regarded as successful bonding, and the case where the wire loop could not be formed without adhering to the wire was regarded as bonding failure.
A value obtained by dividing the number of successful bondings by N (= 40) as a percentage was defined as a “bonding success rate”.

  Subsequently, for the sample for which bonding was successful, the central portion of the formed gold wire loop 2b was pulled vertically with a pull strength tester, and the pull strength and the pull mode were measured.

  The pull strength is a tensile load when the wire is cut and peeled at any location. Of the samples that were successfully bonded, the pull strength of the sample that was cut and peeled with the minimum load was the “minimum pull strength”, and the pull strength of the sample that was cut and peeled with the maximum load was the “maximum pull strength”. The average value of the pull strength was defined as “average pull strength”.

  In the pull mode, the surface of the wire bonding terminal 2a after the pull test was observed with an optical microscope to determine which part of A to G in FIG.

  A value obtained by dividing the number of samples in which the pull mode was good mode by the number of samples subjected to the pull test (successfully bonded) in percentage was defined as “good mode rate”.

  The overall evaluation of the wire bonding property was judged as good (◯) when the bonding success rate was 90% or more, the minimum pull strength was 4 gf or more, the average pull strength was 9 gf or more, and the good mode rate was 100%, otherwise it was judged as poor (×).

<Solder ball bonding strength>
The evaluation printed circuit board 1 after plating was preheated at 180 ° C. for 3 hours. Subsequently, the reflow process was performed 3 times on peak temperature conditions 250 degreeC. After allowing to cool, flux is applied to the ball terminal surface and a lead-free solder ball having a diameter of 0.45 mm (Sn 95.5 mass%, Ag 4 mass%, Cu 0.5 mass%) is mounted at N = 60, and the peak temperature condition The solder balls were fused by reflowing at 250 ° C. in a nitrogen atmosphere. For the fused solder balls, the tensile strength was measured at room temperature, and the average value of “solder ball bonding strength (gf)” was evaluated. For the measurement, a bond tester (Dage # 4000, manufactured by Dage) was used, and the pulling speed was set to 5000 μm / sec.

Evaluation Example 23
The same test and evaluation as in Evaluation Example 13 were performed except that the electrolytic gold plating treatment time was 240 seconds and the thickness of the gold plating film was 0.4 μm.

[Summary of evaluation results]
The results of Evaluation Examples 1 to 23 are shown in Table 6 and Table 7.

The contact terminals (Evaluation Examples 1 to 12) obtained by forming an electrolytic gold plating film on a base nickel film obtained from an electrolytic nickel plating solution to which a specific aliphatic organic compound is added have a thin gold plating film. Even when the gold plating film was thick (Evaluation Example 23), it was confirmed that the film had good wire bonding properties that were inferior.
It was also confirmed that the solder ball bonding strength was improved by reducing the gold plating film thickness.

  Evaluation Examples 13, 16, 18, 20, and 22 also have a maximum strength surface of (200), but by adding an appropriate amount of a specific aliphatic organic compound, the crystal orientation of nickel can be controlled, and Evaluation Example 1 to 12 satisfy the requirements (a), (b), (c), and (d), and the (200) plane can be particularly preferentially oriented ((200) plane orientation is strengthened). became. Thereby, even if the gold plating film thickness became thin, it has confirmed that wire bondability became favorable.

  In Evaluation Examples 10 and 22, a nickel sulfate bath that is common in the production of electronic components was used. In Evaluation Example 10 in which the specific aliphatic organic compound was added, the requirements (a), (b), (c), and (d) were satisfied, and the wire bonding property was good even when the gold plating film thickness was reduced. It was. On the other hand, in Evaluation Example 22 in which the specific aliphatic organic compound is not added, the maximum strength surface is the (200) surface. The wire bonding property was poor.

  Evaluation Example 14 is a case where an excessive amount of the specific aliphatic organic compound is added. By adding an excessive amount, the maximum strength surface became the (111) surface, and the wire bonding property was poor.

  Evaluation Example 15 is a case where a compound having only one hydroxyl group in the molecule is added. When the maximum strength surface was the (111) surface and the gold plating thickness was 0.1 μm, the wire bonding property was poor.

  Evaluation Example 16 is a case where a “compound having only one hydroxyl group in the molecule”, which is different from Evaluation Example 15, is added. Although the maximum strength surface is the (200) surface, I (200) is as small as 478 and does not satisfy the requirements (a) and (d). Was bad.

  Evaluation Example 17 is a case where an aliphatic organic compound having two hydroxyl groups having divalent sulfur in the molecule is added. When the maximum strength surface was the (111) surface and the gold plating thickness was 0.1 μm, no wire was attached. Also, the solder ball bonding strength was greatly reduced.

  Evaluation Example 18 is a case where saccharin sodium dihydrate having hexavalent sulfur (sulfonyl group) generally called a primary brightener is added. The maximum strength surface is the (200) surface, but I (200) is not sufficiently large as 841 and does not satisfy the requirements (a) and (d). The wire bonding property was poor. Moreover, compared with Evaluation Examples 1-12, it became a result with low solder joint strength.

  Evaluation Example 19 is a case where butynediol, which is a specific aliphatic organic compound, is added together with saccharin sodium dihydrate. The amount of sodium saccharin dihydrate added is larger than the amount of butynediol added (about 4 times in molar ratio), the effect of addition of butynediol, which is a specific aliphatic organic compound, is inhibited, and the maximum strength surface is (111 ) When the thickness of the gold plating was 0.1 μm, no wire was attached and the solder joint strength was low.

  Evaluation Example 20 is a case where a cycloaliphatic organic compound having no two hydroxyl groups is added. Although the maximum strength surface is the (200) surface, I (200) does not increase compared with the evaluation example 9, and the requirements (a) and (d) are not satisfied. The wire bondability was poor at 1 μm.

  Evaluation Example 21 is a case where an aliphatic organic compound having three hydroxyl groups in the molecule is added. When the maximum strength surface was the (111) surface and the gold plating thickness was 0.1 μm, the wire bonding property was poor.

As is clear from the surface roughness values of the contact terminals in each evaluation example, a satisfactory wire bonding property can be obtained when the gold plating film thickness is reduced simply by making the terminals smooth with little surface roughness. Not found out.
That is, it was confirmed that the wire bonding property was improved by controlling not only the surface roughness but also the crystal orientation of the underlying nickel film.

  The method of the present invention can be widely used for manufacturing printed circuit boards, lead frames and the like because an electronic component contact member having excellent wire bonding reliability and solderability can be obtained even if the gold plating film is thinned. Is.

DESCRIPTION OF SYMBOLS 1 Evaluation printed circuit board 2 Wire bonding terminal part 2a Wire bonding terminal 2b Wire loop 2c Ball bond 2d Wedge bond 3 Gate part 4 Ball terminal part

Claims (14)

  An electronic component in which a base nickel plating film is formed on a copper or copper alloy substrate by an electrolytic plating method using an electrolytic nickel plating solution, and then a gold plating film or a gold alloy plating film is formed on the base nickel plating film A method for manufacturing a contact member according to claim 1, wherein the underlying nickel plating film has a (200) plane as the crystal plane showing the maximum peak intensity of X-ray diffraction.   The method for producing an electronic component contact member according to claim 1, wherein an average thickness of the gold plating film or the gold alloy plating film is 0.05 to 0.3 μm.   3. The electrolytic nickel plating solution according to claim 1, wherein the electrolytic nickel plating solution contains an aliphatic organic compound having 2 to 10 carbon atoms having two hydroxyl groups in the molecule and no sulfur in the molecule. Manufacturing method of electronic component contact member.   The aliphatic organic compound is butanediol, butenediol, butynediol, hexanediol, hexenediol, hexynediol, dimethylhexanediol, dimethylhexenediol, dimethylhexynediol, butanediol ethoxylate, butenediol ethoxylate, butyne Diol ethoxylate, dimethyloctanediol, dimethyloctenediol, dimethyloctynediol, hexadiynediol, dioxanediol, 1,3-dihydroxyacetone dimer, dichlorobutanediol, dichlorobutenediol, dichlorobutynediol, dibromobutanediol, dibromobutenediol And at least one compound selected from the group consisting of dibromobutynediol and the electronic component contact according to claim 3 Method for producing a member. The method for producing an electronic component contact member according to claim 3, wherein the aliphatic organic compound is a compound represented by the following general formula (1).
[In General Formula (1), X is a bivalent coupling group which consists of a carbon atom and / or an oxygen atom, and has a double bond or a triple bond. ] The X-ray diffraction peak intensities corresponding to the (200) plane, (111) plane, (220) plane, and (311) plane of the base nickel plating film are I (200), I (111), I ( 220) and I (311), the method of manufacturing an electronic component contact member according to any one of claims 1 to 5, wherein all of the following relationships (a) to (c) are satisfied.
(A) I (111) / I (200) ≦ 0.3
(B) I (220) / I (200) ≦ 0.05
(C) I (311) / I (200) ≦ 0.05 When the peak intensities of X-ray diffraction corresponding to the (222) plane and the (400) plane of the base nickel plating film are I (222) and I (400), respectively, the following relationship (d) The manufacturing method of the electronic component contact member of Claim 6 which satisfy | fills.
(D) I (200) / [I (200) + I (111) + I (220) + I (311) + I (222) + I (400)] ≧ 0.7   The electrolytic nickel plating solution contains one or more compounds selected from the group consisting of nickel sulfamate, nickel sulfate, nickel chloride, nickel bromide and nickel carbonate as a nickel source. The manufacturing method of the electronic component contact member of any one of Claims.   The electrolytic nickel plating solution contains at least one compound selected from the group consisting of boric acid, metaboric acid, acetic acid, tartaric acid and citric acid, and salts thereof as a pH buffering agent. The manufacturing method of the electronic component contact member of any one of Claims 8.   10. The electronic component contact member according to any one of claims 1 to 9, wherein the electrolytic nickel plating solution does not contain a sulfur-containing compound (excluding compounds in which all sulfur atoms are hexavalent). Method. A method for producing a gold plating film or a gold alloy plating film for use in the method for producing an electronic component contact member according to any one of claims 1 to 10,
A gold plating film or a gold alloy plating film having an average thickness of 0.05 to 0.3 μm is formed on a nickel plating film whose crystal plane showing the maximum peak intensity of X-ray diffraction is a (200) plane. A method for producing a gold plating film or a gold alloy plating film. An electronic component contact member in which a base nickel plating film is formed on a copper or copper alloy substrate, and a gold plating film or a gold alloy plating film is formed on the base nickel plating film,
In the base nickel plating film, the crystal plane showing the maximum peak intensity of X-ray diffraction is the (200) plane, and the (200) plane, (111) plane, (220) plane, (311) plane, (222) plane And X-ray diffraction peak intensities corresponding to the (400) plane are I (200), I (111), I (220), I (311), I (222) and I (400), respectively. An electronic component contact member characterized by satisfying all of the following relationships (a) to (d):
(A) I (111) / I (200) ≦ 0.3
(B) I (220) / I (200) ≦ 0.05
(C) I (311) / I (200) ≦ 0.05
(D) I (200) / [I (200) + I (111) + I (220) + I (311) + I (222) + I (400)] ≧ 0.7   The electronic component contact member according to claim 12, wherein an average thickness of the gold plating film or the gold alloy plating film is 0.05 to 0.3 μm.   The method for producing an electronic component contact member according to any one of claims 1 to 10, wherein the electrolytic nickel plating solution is for forming a base nickel plating film.