JPH0261095A - Method for plating chip parts - Google Patents

Abstract

PURPOSE:To prevent deterioration of current effect by improvement of agitating efficiency and to uniformize thickness of the films plated on respective chip parts by additionally introducing ceramic dummies besides the chip parts and steel ball dummies into a barrel and performing plating. CONSTITUTION:The spherical ceramic dummies 11, 12 are additionally introduced into a barrel 13 as plating dummies in addition to steel ball dummies 16 and barrel plating is performed on the chip parts while rotating these dummies. As a result, the dummies 16 can be uniformly mixed with the chip parts by freely moving the dummies 11, 12. Therefore flow of current is not deviated to the dummies 16 side and uniform current distribution is obtained and thereby current efficiency is improved. In barrel plating production of the chip parts, simultaneously large quantities of plating production are enabled. Furthermore stabilized plating quality wherein dispersion of thickness of the plated films is made less is obtained. Further a plating electrode body 14 in a cathode side and the angular chip fixing resistors 15 utilized as the chip parts are shown in the figure, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of plating chip components used in electronic equipment.

BACKGROUND OF THE INVENTION Conventionally, in this type of plating method, barrel plating has been carried out as shown in FIG. Fig. 6 shows a schematic diagram of the stirring and mixing state of each input into the barrel during barrel plating of chip parts as an example, when the barrel rotates, where 1 is the barrel and 2 is the cathode side plating electrode rod. A chip component (product to be plated) 3 and a steel ball dummy (conductor dummy) 4 are inserted into the barrel 1, and by rotating the barrel 1, conduction between the chip components 3 is established by the steel ball dummy 4. It was then plated.

In such conventional methods, the chip component and the steel ball dummy are not mixed uniformly during the barrel rotation, causing a separation phenomenon, and the uniform current density, which is the most important for plating, cannot be maintained. This method has the disadvantage that a uniform plating film thickness cannot be obtained for each individual chip component, resulting in large variations. Furthermore, the separation phenomenon hinders the greatest advantage of the barrel plating method, which is that a large number of chip parts can be plated at the same time.

Problems to be Solved by the Invention In order to uniformly mix chip components and steel ball dummies using such a conventional method, a larger amount of steel ball dummies must be introduced. However, if a large number of steel ball dummies are introduced, the current flow will be biased toward the steel ball dummies, resulting in an extremely low current efficiency.As a result, the growth rate of plating on chip components will slow down, which will worsen production efficiency. do. That is, there is a problem in that unless plating is performed for a long time, the desired plating film thickness cannot be obtained. In addition, if a new device with a stirring function is installed inside the barrel and an attempt is made to eliminate the separation phenomenon between the chip components and the steel ball dummy, the chip components will be damaged due to contact with the stirring device. New problems arise. Furthermore, in order to make the stirring state uniform, there is a method of mixing steel ball dummies of different sizes, but with this method, the current flows more easily to the steel ball dummy side, and as a result, the current flows to the chip parts. This has the problem that the plating growth rate becomes slow and the productivity and current efficiency deteriorate.

The present invention solves the problem of the above-mentioned inconsistency in the mixing state of the chip parts and steel ball dummy in the barrel and the reduction of the current effect, thereby reducing the variation in the plating film thickness of each type of chip parts, and The purpose is to provide a method for plating.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention adds chip parts and steel ball dummies to the barrel, adds a new ceramic dummy, and improves the agitation during plating. This improves efficiency.

Effect: According to this configuration, a spherical ceramic dummy is added in addition to the steel ball dummy as a plating dummy, and barrel plating is performed while rotating, so that the ceramic dummy moves freely and the chip parts and the steel ball dummy are evenly coated. The current flow is not biased toward the steel ball dummy, resulting in a uniform current distribution and improved current efficiency. As a result, a large amount of plating can be produced at the same time in the barrel plating production of chip parts, and stable plating quality with small variations in film thickness can be obtained, making it possible to produce highly reliable products. An embodiment of the barrel plating method for a rectangular chip fixed resistor according to the invention will be described with reference to the drawings. FIG. 2 shows spherical ceramic dummies of different sizes that can be pressed and pressed according to the present invention, 11 is a ceramic dummy with a diameter of 12 m, and 12 is a ceramic dummy with a diameter of 8 mm. 1st
The figure shows the state of stirring and mixing in the barrel as the barrel rotates during plating of the square chip fixed resistor when ceramic dummies 11 and 12 of Figure 2, the square chip fixed resistor, and the steel ball dummy are put into the barrel. It is a schematic diagram.

13 is a barrel, 14 is a cathode side plated electrode rod, 15 is a square chip fixed resistor, and 16 is a steel ball dummy.Furthermore, Fig. 3 shows a square chip fixed resistor made according to the present invention. FIG. 17 is an insulating substrate such as alumina, 18 is overcoat glass, 19 is a silver-based electrode layer, 2Q is a nickel plating layer, and 21 is a solder plating layer.

The present invention eliminates the conventional drawback, that is, the state of separation between the chip component and the steel ball dummy, by inserting spherical ceramic dummies of different sizes into the barrel as shown in FIG. It is possible to solve the problem of increased variation in plating film thickness due to a decrease in plating thickness and the inability to plate a large number of chip components at the same time.

Hereinafter, specific examples will be described regarding electroplating of a rectangular chip fixed resistor using the ceramic dummy of the present invention. 300,000 square chip fixed resistors with 10 slots, steel ball dummies 4.5 to 9, and ceramic dummies 1 to 9 of the present invention (ceramic dummy size ratio 1:1) are placed in a barrel, and while rotating, nickel and , solder plating was carried out for 50 feet, and the plating film thickness within a lot and between lofts was confirmed and compared with the conventional method.

However, the plating conditions other than the number of square chip resistors used are the same.

The thickness of each plating film was measured by randomly sampling n = 100 pieces for each loft, and measuring the thickness of the nickel plating layer 20. The thickness of each plating film of the solder plating layer 21 is measured.

The results are shown in FIGS. 4 and 5.

Regarding the variation in nickel plating film thickness (δn,),
The product of the present invention has a diameter of about 1.7 μm compared to a conventional product of about 0.
It decreased significantly to 7 μm. In addition, the variation in solder plating film thickness (δn-1) has been significantly reduced from about 1.8 μm to about 0.8 μm compared to the conventional product, resulting in a stable plating film thickness with small variations. It will be done.

Historically, the number of 10-t sizes was 60,000 to 150,000 pieces in the past, but with the present invention, the number can be expanded to 300,000 pieces, and a highly productive plating method can be established.

Effects of the Invention As described above, by using a ceramic dummy for barrel plating according to the present invention, variations in the plating film thickness are small and a large amount of plating can be applied, thereby making it possible to stabilize the square chip fixed resistor. This has the effect of ensuring highly reliable and homogeneous product quality and increasing production capacity.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining the plating method of the present invention,
Fig. 2 is a plan view showing the ceramic dummy used in the plating method shown in Fig. 1, Fig. 3 is a cross-sectional view of a rectangular chip fixed resistor, and Figs. The characteristic diagram, FIG. 6, is a schematic diagram of the state of stirring and mixing of various materials introduced into the barrel during conventional barrel plating of chip components. 11.12...Ceramic dummy, 13...
... Barrel, 14 ... Cathode side plated electrode rod,
15... Square chip fixed resistor, 16...
・Name of steel ball dummy agent: Patent attorney Shigetaka Awano and 1 other persontt
, /2-m- I O --- Ceramic dummy barrel side plated square pole, knob fixing company #, vessel stino ball dummy Fig. 2 Fig. Fig. Fig.

Claims (1)

[Claims] A method for plating chip parts, characterized in that a conductor dummy and a ceramic dummy are put together with a chip part to be plated, and plating is applied.