JPH08100295A - Plating method and barrel device for plating - Google Patents

Abstract

PURPOSE: To form plating films having a uniform thicknesses on many small-sized works at a good yield by providing a barrel type plating device with stirring plates formed to a specific structure within a barrel, thereby uniformly stirring the works at the time of subjecting these works to plating with this plating device. CONSTITUTION: The many small-sized works to be plated and dummies are put into the hexagonal columnar barrel 1 having many small holes for putting in and out of a plating liquid on its outside surface and these works are subjected to plating by rotating the barrel around its longitudinal axis in the plating liquid. Three pieces of the agitating plates 10 are mounted at both ends faces 11, 12 of the barrel by opening a prescribed angle around the central axial line of the barrel in the state of parting the plates from the inner peripheral surface of the barrel in the longitudinal direction of the barrel. These agitating plates 10 have a hexagonal section of which the side ends 10B, 10C of the section 10A perpendicular to the longitudinal direction form a vertex. The many works to be plated and the dummies are evenly agitated by rotation of the barrel. The plating films having the uniform thickness are thus formed on the works at the high yield without adhesion of the works to each other or the works and the dummies by the plating films.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electroplating electronic parts such as resistors and capacitors, and a barrel device for plating.

[0002]

2. Description of the Related Art As is well known, a barrel device includes a large number of electronic parts (resistors, capacitors, etc.) in a barrel (rotating container).
, And all the parts are electroplated at one time. The barrel has many holes. The barrel is immersed in the plating solution and plated while rotating.

A typical barrel device is shown in FIG. This barrel device 50 includes a barrel 51 having a hexagonal prism shape and a barrel 5
6 plastic nets 52 arranged on the respective surfaces of 1 and 5 pressing plates 53 for pressing the nets 52 on the respective surfaces of the barrel 51, and also functioning as pressing plates and can be removed or opened / closed. A free lid 54 and a net receiving plate 55 that presses each net 52 at each ridgeline (corner) R of the barrel 51 are provided.

Although not shown in FIG. 7, the net 52 is not shown.
Has a large number of holes, and the holding plate 53 also has a rectangular slit 53.
have a. Also, on both end surfaces of the barrel 51, the barrel 5
A hole 5 is provided at a portion through which a rotation shaft (not shown) passes when the 1 rotates.
1a is provided. When performing electroplating on a work (electronic component) using such a barrel device 50, as shown in FIG. 8, a work 60 and a dummy (steel shot) 61 are put into the barrel 51. In this state, the barrel 51 is rotated in one direction (the arrow direction in FIG. 8) and the surface of the work 60 is plated.

[0005]

When electroplating is performed using the barrel device 50 as described above, as shown in FIG. 8, the workpiece 60 and the dummy 61 in the barrel 51 are
Each of them does not flow so much in the state of being separated into layers, and the stirring state becomes very bad. If the plating film growth on the work 60 and the dummy 61 progresses while the stirring state is poor as described above, the work 60 and the dummy 61 are likely to stick to each other and agglomerate easily. Work 60 that became this lump
Is rejected as a defective product, resulting in a considerable decrease in production yield. In particular, such a lump is likely to occur at each ridge portion in the barrel 51.

Further, in the barrel, each work 60
Since the conduction state varies during the growth of the plating film, it is difficult to uniformly plate all the works 60 in the barrel 51.
It will be mixed depending on. Then, JP-A-3-5309
As described in Japanese Patent Laid-Open No. 7-76, the scraping plates attached and fixed to the ridge line portion of the inner peripheral surface of the barrel are installed at equal intervals to uniformly stir the input material in the barrel and to cause variations in the plating film thickness. A barrel device for plating has been proposed to make the size smaller.

However, in this device, since the scraping plate is attached and fixed to the inner peripheral surface of the barrel, the input material located at the base of the scraping plate with respect to the barrel peripheral surface is agitated near the center of the barrel. It is pushed by the charged material and is clogged, making it difficult to stir. Moreover, this scraping board
Since it is attached to the ridge of the inner peripheral surface of the barrel where the bulk of the input material is most likely to form, it was not possible to eliminate the formation of the bulk of the work and the dummy.

As described above, when a workpiece is plated by using the barrel device, as shown by the root of the scraping plate with the barrel peripheral surface, the inner surface of the barrel is slightly touched. However, if there is a concavo-convex portion, a lump of the work and the dummy occurs at that portion. There is a strong demand to improve the production yield by reducing defects due to such lumps as much as possible.

Moreover, such a lump is formed in the barrel 5
Since the work 60 may stick inside, it is necessary to remove the work 60 from the barrel after plating the work 60, resulting in very poor maintainability. Further, there is a problem in that the life of the barrel 51 itself is likely to be shortened as the removal processing is repeated, and it is necessary to replace the device frequently.

The present invention has been devised under the above circumstances, and a plating method and a plating method capable of improving the stirring state in the barrel and suppressing variations in plating, sticking of works, etc. To provide a barrel device.

[0011]

Therefore, the present inventor has found the following technique in order to achieve the above object. “The stirring plate is provided in the barrel so as to be separated from the peripheral surface of the barrel, and the stirring plate is formed such that the side end portion of the cross section perpendicular to the longitudinal direction has an apex angle, and the barrel is rotated. Therefore, the plating method is characterized in that the input material is plated while being stirred using a stirring plate. ”Further, the present inventor has found the following apparatus.

"A barrel apparatus for plating comprising a barrel having a polygonal column shape and a stirring plate provided in the barrel and spaced from the peripheral surface of the barrel, the stirring plate having a cross section perpendicular to the longitudinal direction. The barrel device for plating is characterized in that the side ends are formed to have a vertical angle. "

[0013]

According to such a method and apparatus, by forming the side end of the stirring plate into a vertical angle, the vertical angle portion pushes up the charging product when the stirring plate dives through the charging product. Without this, the input can be smoothly slid downward along the end face of the apex, and the floating of the input in the barrel is reduced.

Therefore, the charge in the barrel is uniformly stirred and
As they are mixed, variations in plating and sticking of workpieces are greatly reduced. Further, when a plurality of stirring plates of the present invention are provided with a predetermined angle about the center axis of the barrel, a good stirring state as described above can be obtained a plurality of times during one rotation of the barrel.

Further, when the stirring plate of the present invention is provided along the longitudinal direction of the barrel so as to reach both inner end surfaces of the barrel, the charge is well stirred over substantially the entire region of the barrel in the longitudinal direction. be able to. In addition, when the stirring plates of the present invention are provided so that regular polygonal columns are formed in the barrel by the planes in which they exist, the charge to be pressed against them is slanted downward along the pressing surface of the stirring plate. It becomes easier to avalanche, and the stirring condition becomes even better.

Further, when the stirring plate of the present invention is provided on a plane passing through the ridgeline of the barrel or in the vicinity thereof and in a direction substantially perpendicular to the peripheral surface of the barrel, the stirring plate is charged in the vicinity of the ridgeline portion. Things can be stirred even better.

[0017]

EXAMPLE An example of the plating method and the barrel device for plating of the present invention will be described below, but the present invention is not limited thereto. As shown in FIG. 1, this barrel device includes a hollow hexagonal columnar barrel 1 and three stirring plates 10 provided inside the barrel 1.

These stirring plates 10 are provided so as to face each other in the same direction along the longitudinal direction of the barrel 1 and on a plane including the ridgelines R on both sides of one ridgeline (corner) R of the barrel 1. Further, they are provided at a predetermined angle with respect to the central axis line M in the longitudinal direction of the barrel 1 so as to be oriented in a direction substantially perpendicular to the inner peripheral surface of the barrel 1. In short, the stirring plate 10 is not formed on the plane including the central axis line M of the barrel 1, but exists on a plane different from this plane.

Further, each stirring plate 10 is provided so as to be separated from the peripheral surface of the barrel 1, and the separation dimension is 12
It is about mm. Further, as is clear from FIGS. 2A and 2B, the stirring plate 10 is formed in a vertical angle shape on the main body 10A and both side end portions of the main body 10A in a sectional shape perpendicular to the longitudinal direction. The main body 10A has a main surface 10a and a back surface 10b, and each of the apex angle portions 10B and 10C is composed of a pair of apex portions 10B and 10C.
It has 0c, 10d; 10e, 10f and has a hexagonal shape as a whole.

The stirring plate 10 is provided so as to reach both inner end surfaces 11 and 12 of the barrel 1, and more specifically, both ends thereof are connected and fixed to both inner end surfaces 11 and 12, and the length thereof is long. The length a in the direction is approximately equal to the length in the longitudinal direction of the barrel 1, and the thickness b of the main body 10A is about 10 mm in this embodiment. The number of nets 2 provided around the barrel 1 is one in this embodiment, and has a large number of holes 2a. The net 2 corresponds to 5 out of 6 surfaces of the barrel 1, and a lid (not shown) is arranged on the remaining 1 surface where the net 2 is not provided. By using only one net 2, not only the rate of opening of the hole 2a can be increased and the work can be effectively prevented from being caught,
The net receiving plate (see reference numeral 55 in FIG. 7) is not required, and the structure is simplified.

Further, rod-shaped rotating shafts 15 and 16 are inserted into substantially central portions of both end faces 11 and 12 of the barrel 1, and the barrel 1 is rotatably provided around these rotating shafts 15 and 16. ing. These rotary shafts 1
The reference numerals 5 and 16 are arranged in the barrel 1 so as to face each other while being separated from each other (these rotation axes do not necessarily coincide with the central axis of the barrel).

FIG. 4 shows a stirring state when plating is performed using such an apparatus. First, a work 20, a ceramic ball 21, and a dummy (steel shot) 22, which are the inputs, are placed in the barrel 1, and the barrel 1 is dipped in a plating solution. Next, when the barrel 1 rotates about the rotary shafts 15 and 16, the work 20, the ceramic balls 21, and the dummy 22 are agitated / mixed.
Since the stirring plate 10 is spaced apart from the peripheral surface of the barrel 1 and provided on a plane different from the plane including the central axis M of the barrel 1, the charge can be stirred as follows.

That is, the stirring plate 10 rotates as the barrel 1 rotates while pressing the charged material on the surface facing the direction of rotation. At this time, since there is a gap between the stirring plate 10 and the peripheral surface of the barrel 1, the input material is agitated while passing through this gap portion, and is agitated in a very good state, which in turn causes sticking. The occurrence of lumps is greatly reduced.

Further, the stirring plate 10 allows the charge to pass through a gap between itself and the peripheral surface of the barrel 1, while pressing the charge that does not pass through this gap to the upper layer of the charge in the barrel 1. Push up. At this time, the stirring plate 10 is inclined so that the main surface 10A that presses the charge goes toward the lower inside of the barrel 1 as the barrel 1 rotates. Main surface 1 of plate 10
As it will fall down diagonally along 0A,
Lifting of the charge in the barrel 1 is considerably reduced. In addition, the avalanche dropped input is mixed with the input that passes through the gap and wraps around to the back surface 10B side of the stirring plate 10, so that the agglomerated input is stirred better.

Further, since the agitating plate 10 is formed with the apex angle portions 10B and 10C at both side ends thereof, when the agitating plate 10 submerges in the charged material as the barrel 1 rotates. , The top corner portion 10B (or 10C) is the first to dive through the input, and the input is the end face 10c or 10d.
(Or 10e or 10f) will cause the avalanche to fall obliquely downward, so that the floating of the input material in the barrel 1 is considerably reduced.

That is, when a stirrer plate having a flat side end instead of a hexagonal cross-sectional shape perpendicular to the longitudinal direction as in the present embodiment is used instead of the hexagonal one having a vertical corner as in this embodiment, , When the stirring plate submerges between the charged materials, this flat side end pushes up the charged materials, and the charged materials thus pushed up tend to be a lump, and when the plating growth proceeds in this state, There is a variation in the conduction state during the growth of the plated film, which causes non-uniformity of the plated film thickness.

Therefore, as described above, by providing the apex angle portions at both end portions of the stirring plate, the apex portion does not push up the input material when the agitating plate submerges in the input material.
It is possible to smoothly drop the charged material obliquely downward along the end face of the apex portion, which can contribute to making the plating film thickness uniform. Moreover, since the plurality of stirring plates are provided at a predetermined angle with respect to the central axis M of the barrel 1, a good stirring state as described above can be obtained a plurality of times during one rotation of the barrel 1. it can.

Further, since the agitating plate is provided along the longitudinal direction of the barrel so as to reach both inner end surfaces of the barrel, the agitated material is well agitated over substantially the entire area of the longitudinal direction of the barrel. be able to. In addition, the stirring plate,
When provided so that the regular polygonal column is formed in the barrel by the plane in which each is present, it is easy to avalanche the input material pressed against this along the pressing surface of the stirring plate and obliquely downward, The stirring state becomes even better.

Further, since the agitating plate is provided on a plane passing through the ridgeline of the barrel or its vicinity and in a direction substantially perpendicular to the peripheral surface of the barrel, the stirring plate is put in the vicinity of the ridgeline portion in the barrel. Things can be stirred even better.
As described above, when the plating method of the present invention is used, the input material in the barrel is stirred and mixed substantially uniformly, resulting in uneven plating.
Work sticking will be greatly reduced.

Next, the results of using the plating method and apparatus of the present invention will be described with a difference from the comparative example. Figure 5
The distribution of the plating film thickness (μm) and the standard deviation σ when the work is plated with Ni using the method of the present invention and the conventional method are shown. The numbers in the figure are average values,
000, XX0, etc. represent resistance values, 000 is 0Ω, XX
0 is 10Ω, XX1 is 100Ω, XX2 is 1kΩ, XX
3 shows 10 kΩ and XX4 shows 100 kΩ. It can be seen from FIG. 5 that the barrel device of the present invention has less variation in plating.

Further, FIG. 6 shows the plating film thickness (μm) and the standard deviation σ of Examples 1 to 6 and Comparative Examples 1 to 6 when Sn / Pb plating was similarly applied. Here too, the plating variability is significantly reduced. In the present embodiment, the stirring plate is separated from the peripheral surface of the barrel by about 12 mm, but the invention is not limited to this, and the separation dimension is larger than the maximum width dimension of the workpiece and the workpiece. It is preferable that the size is smaller than twice the maximum width dimension of the above. If the spacing dimension is provided in this way, it is difficult for the work to be clogged in this gap, and a good stirring state can be maintained.

The ridgeline of the barrel in the present invention refers to a line segment, that is, a corner line including the apexes of the portion forming the apex angle on the peripheral surface of the barrel. Further, the central axis line in the longitudinal direction of the barrel in the present invention refers to a line segment passing through respective center points on both end faces of the barrel. Further, in the present embodiment, a hexagonal columnar barrel is used, but the present invention is not limited to this, and it is also applicable to an octagonal columnar barrel.

[0033]

As described above, according to the plating method of the present invention, the side edge of the stirring plate provided in the barrel is formed into a vertical angle so that the barrel is rotated and the stirring plate is placed in the charge. When submersing in, the apex does not push up the input,
Since the input materials smoothly fall obliquely downward along the end face of the apex, the input materials (workpieces, dummies, etc.) do not float individually in the barrel and can be stirred more uniformly in a lump. Since the occurrence of agglomeration due to the sticking of the works to each other and the work and the dummy in the barrel is reduced, the variation in the plating film thickness is reduced,
Highly reliable plated products can be obtained.

Further, in the plating barrel device of the present invention, the charged material can be satisfactorily stirred in the barrel, so that the plating can be efficiently applied. Moreover, since the above lumps are unlikely to occur,
It does not require much work such as removing the lumps and has excellent maintainability, and also has the effect of significantly extending the life of the barrel itself.

[Brief description of drawings]

FIG. 1 is a perspective view showing a barrel in a barrel device of the present invention.

2A and 2B are a plan view and a side view of a stirring plate provided inside the barrel shown in FIG.

FIG. 3 is a perspective view showing a state in which a net is provided around a barrel.

FIG. 4 is a vertical cross-sectional view showing a state when the input material in the barrel is stirred using the plating apparatus of the present invention.

FIG. 5 is a diagram showing the relationship between the plating film thickness and standard deviation when Ni plating is performed using the present invention and the conventional plating apparatus.

FIG. 6 is a schematic diagram showing an example of Sn / Sn using the present invention and a conventional plating apparatus.
It is a figure which shows the relationship between the plating film thickness when Pb plating is applied, and the standard deviation when plating is applied.

FIG. 7 is a partially omitted perspective view of a plating apparatus according to a conventional example.

FIG. 8 is a transverse cross-sectional view showing a state when the input material in the barrel is stirred by using the plating apparatus shown in FIG.

[Explanation of symbols]

 1 Barrel 2 Holes 3 Net 10 Stirrer Plate 11, 12 Barrel Bottom 15, 16 Rotating Shaft 20 Work 21 Ceramic Ball 22 Dummy M Barrel Center Axis R Barrel Ridge

Claims (9)

[Claims] 1. A stirring plate is provided in the barrel so as to be separated from the peripheral surface of the barrel, and the stirring plate is formed such that the side end of a cross section perpendicular to the longitudinal direction has an apex angle. A plating method characterized in that by rotating a barrel, an agitating plate is used to agitate an input material while plating. 2. The plating method according to claim 1, wherein the stirring plate is provided on a plane different from a plane including a central axis line in the longitudinal direction of the barrel. 3. The plating according to claim 1 or 2, wherein a plurality of stirring plates provided at a predetermined angle with respect to the central axis of the barrel are provided to stir the input material while stirring. Plating method. 4. The stir plate is provided so that a regular polygonal column is formed in the barrel by the planes on which the stir plates are present, and the stir plate is used to stir the input while plating. The plating method according to claim 3. 5. The plating is performed while stirring the charge using the stirring plate provided on a plane passing through the ridgeline of the barrel or in the vicinity thereof and provided in a direction substantially perpendicular to the peripheral surface of the barrel. Claim 1 thru | or 4 characterized by the above-mentioned.
The plating method described in. 6. The plating is performed while stirring an input material by using the stirring plate provided along the longitudinal direction of the barrel so as to reach both inner end surfaces of the barrel. Item 5. The plating method according to Item 5. 7. A barrel device for plating, comprising: a polygonal columnar barrel; and a stirring plate provided in the barrel and separated from a peripheral surface of the barrel, wherein the stirring plate has a cross section perpendicular to a longitudinal direction. The plating barrel device is characterized in that the side end portion of the is formed to have a vertical angle. 8. The plating barrel device according to claim 7, wherein the stirring plate is provided on a plane different from a plane including a central axis line in the longitudinal direction of the barrel. 9. The stirring plate is provided on a plane including both ridgelines adjacent to each other with one ridgeline of the barrel sandwiched therebetween, and a plurality of stirrers are provided at a predetermined angle around a central axis of the barrel in the longitudinal direction. The barrel device for plating according to claim 7 or 8, characterized in that.