JP7381296B2 - Rotary plating equipment - Google Patents

Description

The present invention relates to a rotary plating apparatus used for plating, for example, electrodes of chip-type electronic components.

Small electronic components such as chip resistors are electrolytically plated to form external electrodes in order to improve solderability to circuit boards and ensure electrical continuity. As a plating device for forming such an external electrode, the object to be plated and the plating solution are put into a plating tank, and the plating tank is rotated to bring the object to be plated into contact with a cathode electrode provided on the outer periphery. A rotary plating apparatus that performs electrolytic plating on an object to be plated is known (for example, see Patent Document 1).

The rotary plating apparatus disclosed in Patent Document 1 includes a disc-shaped bottom plate that is rotatable around a vertical rotation axis, a truncated cone-shaped lid body that is integrally provided on the outer peripheral side wall of the bottom plate, A plating tank defined by the bottom plate and the lid, a box-shaped anode electrode disposed approximately in the center of the plating tank, and a ring-shaped cathode electrode provided on the outer peripheral side wall of the bottom plate, The object to be plated and the plating solution are stored in the plating tank.

In a rotary plating apparatus configured in this way, the plating bath alternately rotates forward and backward around the rotation axis, and this rotation is maintained, and the object to be plated is pressed against the cathode electrode by centrifugal force. Electricity is applied between the anode electrode and the cathode electrode for only a short period of time to perform the plating process.

Japanese Patent Application Publication No. 2018-178181

When plating is performed by rotating the plating tank alternately in the forward and reverse directions, as in the rotary plating apparatus described in Patent Document 1, the object to be plated and the plating solution are stirred, and the object to be plated is A uniform plating layer can be formed. However, when plating is performed by rotating the plating bath alternately in the forward and reverse directions, bubbles form in the plating solution, and these bubbles tend to collect in the center of the plating bath when the plating bath is stopped and the direction of rotation is changed. Therefore, many bubbles concentrate around the anode electrode disposed in the center of the plating tank, and the object to be plated is pushed up by the bubbles and tends to adhere to the anode electrode.

In particular, when the object to be plated has small external dimensions, the anode electrode is surrounded by a cloth anode bag to prevent the object to be plated from flowing in. This prevents the object being pushed up by bubbles from getting tangled with the anode bag. It becomes difficult to separate. As a result, even if the plating tank is rotated again after stopping, the objects to be plated entangled in the anode bag will not be able to ride the flow of the plating solution and will not be able to contact the cathode when electricity is applied, resulting in unplated or abnormal plating. There was a risk that plating defects would occur frequently.

The present invention has been made in view of the actual state of the prior art, and its purpose is to provide a rotary plating apparatus that can reduce plating defects caused by foaming generated in the plating solution. .

In order to achieve the above object, the rotary plating apparatus of the present invention includes a disc-shaped bottom plate that is rotatable in both forward and reverse directions about a vertical axis, and a truncated conical plate that is integrally provided on the outer peripheral side wall of the bottom plate. a plating tank defined by the bottom plate and the lid, a box-shaped anode electrode disposed approximately in the center of the plating tank, and an upper end of the anode electrode. An air blower comprising: an anode cap; and a cathode electrode exposed on the inner circumferential side of the plating bath and forming a part of the outer circumferential side wall, and blowing air onto the anode cap along the outer circumferential surface of the anode electrode It is characterized by having a section.

In a rotary plating apparatus configured in this way, even if bubbles are generated in the plating solution and gather around the anode electrode when the plating tank is stopped and the direction of rotation is changed, the anode cap is By blowing air along the outer circumferential surface of the anode electrode from the air blowing part, the material to be plated pushed up by the bubbles becomes difficult to adhere to the anode electrode, thereby preventing the occurrence of plating defects such as non-plating or abnormal plating. can be reduced.

In the rotary plating apparatus configured as described above, the anode electrode is surrounded by an anode bag having a filter function such as cloth, and air is blown from the air blowing part along the outer circumferential surface of the anode bag. This prevents the material to be plated from flowing into the anode electrode, and also prevents the material to be plated from becoming entangled with the anode bag.

Further, in the rotary plating apparatus having the above configuration, the anode cap includes a cap base that holds the anode electrode, and a cap cover that is joined and integrated to cover the cap base, and the cap base and the cap cover It is preferable that an air supply passage leading to the air blowing part is provided between the anode cap and the anode cap, since the air supply passage can be easily formed in the anode cap.

In this case, if the cap base has a protruding part that protrudes radially outward than the anode bag, and an air blowing part is provided on the lower surface of this protruding part, then the air blowing part The air blown out can be efficiently blown onto the outer peripheral surface of the anode electrode and the anode bag.

Note that the shape and size of the air blowing part are not particularly limited, but if a plurality of air blowing parts are provided at a predetermined interval in the circumferential direction on the lower surface of the protrusion, bubbles can be removed by a small supply of air. Can be blown away efficiently.

Alternatively, it is also possible to adopt a configuration in which the cap base has a protruding part that protrudes outward from the anode bag, and the air blowing part is provided in an annular shape between the protruding part and the cap cover. Then, the air blowing part can be easily formed.

According to the rotary plating apparatus of the present invention, it is possible to reduce plating defects caused by foaming generated in the plating solution.

FIG. 1 is a partially cutaway perspective view of a rotary plating apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory diagram schematically showing a circulation route of a plating solution, etc. in the rotary plating apparatus. FIG. 2 is an explanatory diagram showing an air supply path by an anode cap provided in the rotary plating apparatus. FIG. 4 is an enlarged view of part A in FIG. 3; FIG. 3 is a back view of the anode cap. FIG. 3 is a cross-sectional view of the anode cap. FIG. 7 is a sectional view of a main part showing a modification of the anode cap.

Embodiments of the invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view of a rotary plating apparatus according to an embodiment of the invention.

As shown in FIG. 1, a rotary plating apparatus 100 according to the present embodiment includes a lid 1 having an approximately truncated conical outer shape, a bottom plate 2 disposed to cover the bottom surface of the lid 1, A plating tank 3 defined by the lid 1 and the bottom plate 2, an anode electrode (anode electrode) 4 disposed approximately in the center of the plating tank 3, and a ring-shaped electrode 4 provided on the outer periphery of the bottom plate 2. A cathode electrode (cathode electrode) 5 is provided.

The lid 1 has a protrusion 1a at the lowermost edge (outermost periphery) of the inclined side surface that protrudes outward in a brim shape, and the protrusion 1a is covered by an annular ring member 6. There is. Further, a plurality of openings 1b are provided at a predetermined interval in the circumferential direction at the lower part of the inclined side surface of the lid body 1 for discharging the plating solution and the like stored in the plating tank 3.

The bottom plate 2 includes a disk-shaped base member 7 having an outer diameter that is the same as the outer diameter of the outermost peripheral portion of the lid body 1, and the cathode electrode 5 disposed along the outer peripheral edge of the upper surface of the base member 7. and a spacer ring 8, which is an annular member located below the projection 1a of the lid 1 and having the same diameter as the cathode electrode 5. In the plating tank 3, an outer peripheral side wall is formed by the outer peripheral edge of the base member 7, the cathode electrode 5, the spacer ring 8, and the protrusion 1a.

A plurality of through holes are provided in the ring member 6, the protrusion 1a, the spacer ring 8, and the cathode electrode 5 in the circumferential direction. Then, by inserting the bolt 9 into the through hole in a state where these are overlapped, and screwing the male threaded part provided at the tip part and the female threaded part provided on the base member 7, the lid body 1 and the bottom plate 2 are integrally fixed. Note that the internal space formed by the lid 1 and the bottom plate 2 serves as a plating tank 3.

At the center of the plating tank 3, an anode electrode 4 formed in a box shape made of wire mesh is arranged, and at the center of an anode cap 10 that holds the anode electrode 4, a cap for supplying electricity to the anode electrode 4 is arranged. A support shaft 11 is inserted and fixed. Further, a washing water introduction pipe 12 and a processing liquid introduction pipe 13 are inserted and fixed in the anode cap 10, and various processing liquids are circulated to the plating tank 3 through these washing water introduction pipe 12, processing liquid introduction pipe 13, etc. and discharge.

Further, a liquid level sensor 14 is disposed on the side of the anode cap 10, and the liquid level sensor 14 and the anode electrode 4 pass through an upper opening 1c provided at the top of the lid 1 to the inside of the plating tank 3. has reached. The plating tank 3 stores objects 15 to be plated, such as chip-type resistors, and a plating solution (not shown). In order to prevent the fine objects 15 to be plated from flowing into the anode electrode 4, The anode electrode 4 is surrounded by an anode bag 16 made of cloth or the like having a filter function. Although details will be described later, air is blown from the anode cap 10 toward the outer circumference of the anode bag 16.

A vertically extending rotating shaft 17 is connected to the center of the lower surface of the bottom plate 2, and a conductive member is connected to the negative side of the electrolytic plating power source to supply current to the cathode electrode 5. 18 are in contact. By applying a rotational force to the rotating shaft 17 from a motor (not shown), etc., the plating tank 3 in which the object 15 to be plated and the plating solution (not shown) are stored is horizontally moved around the rotating shaft 17. It is designed to rotate. Specifically, as shown by the white arrow in FIG. 1, the plating bath 3 repeats rotation and stopping at a predetermined speed by rotating clockwise and counterclockwise (forward and reverse directions).

In this way, the plating tank 3 alternately repeats forward and reverse rotation in the horizontal direction, and this rotation is maintained, and as shown in FIG. Electricity is applied between the anode electrode 4 and the cathode electrode 5 for only a certain period of time to perform the plating process.

The objects to be plated by the rotary plating apparatus 100 according to the present embodiment are not limited to chip resistors, but include chip inductors, chip capacitors, composite parts thereof, multiple resistors, and electrode terminals. It can also be used for plating electronic components with

FIG. 2 is an explanatory diagram schematically showing a circulation route for a plating solution, etc. in the rotary plating apparatus 100 according to the present embodiment.

As shown in FIG. 2, in the rotary plating apparatus 100, when the plating solution is discharged from the opening 1b provided in the lid body 1 as the plating tank 3 rotates, at the same time, a new plating solution in the plating solution mother tank 19 is discharged. A plating solution is supplied to the plating tank 3 via a treatment solution introduction pipe 13 . Further, the plating solution discharged from the opening 1b is received by a container 20 that covers the entire exterior of the plating tank 3, and reaches the plating solution mother tank 19 via a processing solution outlet pipe 21.

Note that when discharging the processing solution due to a change in plating type in the rotary plating apparatus 100, the plating tank 3 is rotated at high speed in a predetermined direction, and the centrifugal force at that time is utilized to discharge the plating solution etc. from the opening 1b. The container 20 is designed to receive the liquid.

In the process of rinsing the plating object, rinsing water is supplied from the rinsing water tank 22 into the plating tank 3 through the rinsing water introduction pipe 12, and the rinsing water after rinsing is discharged in the same way as when discharging the processing liquid. This is done by rotating the tank 3 at high speed and utilizing its centrifugal force. The washing water received in the container 20 is returned to the washing water tank 22 via the washing water outlet pipe 23.

3 is an explanatory diagram showing a supply path of air blown from the anode cap 10 to the anode bag 16, FIG. 4 is an enlarged view of section A in FIG. 3, FIG. 5 is a back view of the anode cap 10, and FIG. 1 is a cross-sectional view of an anode cap 10. FIG.

As shown in FIGS. 3 to 6, the anode cap 10 is composed of a cap base 24 that holds the anode electrode 4 and the upper end of the anode bag 16, and a cap cover 25 that covers the cap base 24. The cap base 24 and the cap cover 25 are joined and integrated using fasteners for fixing the support shaft 11, the washing water introduction pipe 12, and the processing liquid introduction pipe 13.

The cap base 24 has a protrusion 24a that protrudes in a brim shape toward the outer circumference at the peripheral edge of its upper end, and an air blowing part 26 is formed on the lower surface of the protrusion 24a. A large number of air blowing portions 26 are formed at regular intervals in the circumferential direction of the protruding portion 24a, and in this embodiment, 36 air blowing portions are formed at regular intervals of 10 degrees in the circumferential direction of the protruding portion 24a. 26 is formed. A groove 24b extending in an annular shape is formed on the upper surface of the cap base 24 near the outer periphery. It communicates with the blowing section 26.

The cap cover 25 has an annular wall 25a projecting upward on its peripheral edge, and a plurality of air supply sections communicating with the grooves 24b of the cap base 24 are provided on the inner bottom surface surrounded by the annular wall 25a. 27 are provided. A tube 28 is connected to each air supply section 27, and air is supplied from these tubes 28 through the air supply section 27 into the groove 24b. At this time, if the air supply parts 27 are arranged at equal intervals along the circumferential direction of the groove 24b, air can be evenly and evenly supplied into the groove 24b, so in this embodiment, Four air supply sections 27 are arranged at equal intervals of 90 degrees in the circumferential direction of the groove 24b.

Note that the cap base 24 and the cap cover 25 are provided with a plurality of through holes 29, and the support shaft 11, the flushing water introduction pipe 12, and the processing liquid introduction pipe 13 are inserted into these through holes 29, respectively. ing. Furthermore, a positioning part 30 consisting of a combination of a concave part and a convex part is formed on the facing surfaces of the cap base 24 and the cap cover 25, and this positioning part 30 allows the relative position of the cap base 24 and the cap cover 25 to be easily adjusted. This allows for alignment.

As mentioned above, when performing plating on the plating object 15 stored in the plating tank 3, the plating tank 3 is rotated alternately in the forward direction and the reverse direction so that the object to be plated 15 is stirred. Bubbles are generated in the plating solution. When the rotation direction of the plating tank 3 is changed and stopped, these bubbles tend to gather in the center of the plating tank 3. There is a risk that the bubbles will concentrate and the object to be plated 15 pushed up by the bubbles will become entangled with the anode bag 16, resulting in plating defects such as non-plating or abnormal plating.

In the rotary plating apparatus 100 according to the present embodiment, air is supplied to the air supply section 27 provided on the cap cover 25 of the anode cap 10 via the tube 28 in order to prevent such plating defects. Air is supplied to the anode bag 16 from each air blowing part 26 formed on the protruding part 24a of the cap base 24 via the air supply passage (groove 24b and gap G) formed between the cap base 24 and the cap cover 25. I try to spray it towards the outer periphery. As a result, even if the object to be plated 15 pushed up by the bubbles approaches the periphery of the anode bag 16, the object to be plated 15 is blown away from the anode bag 16 together with the bubbles, so that the object to be plated 15 is It becomes difficult to get entangled with the anode bag 16, and the occurrence of plating defects such as non-plating and abnormal plating can be reduced.

At this time, since the air blowing part 26 is formed in the shape of a hole on the lower surface of the protruding part 24a of the cap base 24, the air radially jetted from the air blowing part 26 is transferred to the anode bag as shown by the arrow in FIG. It can be sprayed onto the outer peripheral surface of 16. Furthermore, since a large number (for example, 36) of air blowing portions 26 are formed on the lower surface of the protruding portion 24a at regular intervals in the circumferential direction, bubbles can be efficiently blown away with a small amount of air supplied. Note that the number of air blowing parts 26 is not particularly limited, but as the number of air blowing parts 26 increases, bubbles can be blown away more efficiently, but on the other hand, the amount of air supplied increases, so these points should be taken into consideration. The number may be set to an appropriate number.

As explained above, in the rotary plating apparatus 100 according to the present embodiment, bubbles are generated in the plating solution when the plating tank 3 is stopped and the rotation direction is changed, and the bubbles surround the anode electrode 4 in the anode bag. 16, the air is blown along the outer circumferential surface of the anode bag 16 from the air blowing part 26 provided in the anode cap 10, so that the object 15 to be plated that has been pushed up by the bubbles is It becomes difficult to adhere to the anode bag 16, and the occurrence of plating defects such as non-plating and abnormal plating can be reduced.

Furthermore, in the rotary plating apparatus 100 according to the present embodiment, the anode cap 10 includes a cap base 24 that holds the anode electrode 4 and the anode bag 16, and a cap cover that is joined and integrated so as to cover the cap base 24. 25, and between the cap base 24 and the cap cover 25, a concave groove 24b communicating with the air blowing part 26 and a gap G (air supply passage) are provided. A supply passage can be easily formed.

In addition, the cap base 24 has a protruding portion 24a that protrudes radially outward than the anode bag 16, and a hole-shaped air blowing portion 26 is provided on the lower surface of this protruding portion 24a. Air ejected radially from 26 can be efficiently blown onto the outer peripheral surface of the anode bag 16. Furthermore, since a large number of air blowing portions 26 are provided on the lower surface of the protruding portion 24a at predetermined intervals in the circumferential direction, bubbles can be efficiently blown away with a small amount of air supplied.

In the rotary plating apparatus 100 according to this embodiment, the anode electrode 4 is surrounded by an anode bag 16 having a filter function such as cloth, and air is blown from the air blowing part 26 toward the outer circumference of the anode bag 16. Since it is sprayed, it is possible to prevent the minute objects 15 to be plated from flowing into the anode electrode 4 and to prevent the objects 15 to be plated from becoming entangled with the anode bag 16. However, the anode bag 16 may be omitted and the anode electrode 4 may be formed of a fine wire mesh, and air may be blown from the air blowing portion 26 toward the outer circumferential side of the anode electrode 4.

FIG. 7 is a sectional view of a main part showing a modification of the anode cap 10, and parts corresponding to those in FIG. 4 are given the same reference numerals.

As shown in FIG. 7, by tapering the outer circumference of the protrusion 24a of the cap base 24 downward and securing a slit between the outer circumference of the protrusion 24a and the lower outer circumference of the cap base 24. The anode cap 10 is provided with an air blowing portion 26 extending in an annular shape. When such a configuration is adopted, the air blowing part 26 is formed by the slit existing between the cap base 24 and the cap cover 25, so there is no need to make complicated holes in the cap base 24, and the air blowing part 26 can be easily formed.

1 Lid 2 Bottom plate 3 Plating tank 4 Anode electrode 5 Cathode electrode 10 Anode cap 15 Object to be plated 16 Anode bag 17 Rotating shaft 24 Cap base 24a Projection 24b Groove (air supply passage)
25 Cap cover 25a Annular wall 26 Air blowing part 27 Air supply part 28 Tube 29 Through hole 30 Positioning part G Gap (air supply passage)
100 Rotary plating equipment

Claims (6)

It is defined by a disc-shaped bottom plate that is rotatable in both forward and reverse directions around a vertical axis, a truncated cone-shaped lid body that is integrally provided on the outer peripheral side wall of the bottom plate, and the bottom plate and the lid body. a plating tank; a box-shaped anode electrode disposed approximately in the center of the plating tank; an anode cap that holds the upper end of the anode electrode; A cathode electrode forming part of the side wall,
A rotary plating apparatus characterized in that the anode cap is provided with an air blowing section that blows air along the outer peripheral surface of the anode electrode. The rotary plating apparatus according to claim 1,
A rotary plating apparatus, wherein the anode electrode is surrounded by an anode bag having a filter function, and air is blown from the air blowing section along the outer peripheral surface of the anode bag. The rotary plating apparatus according to claim 2,
The anode cap includes a cap base that holds the anode electrode, and a cap cover that is joined and integrated so as to cover the cap base, and the air is disposed between the cap base and the cap cover. A rotary plating device characterized by being provided with an air supply passage leading to a blow-off section. The rotary plating apparatus according to claim 3,
The rotary plating apparatus is characterized in that the cap base has a protrusion that protrudes radially outward than the anode bag, and the air blowing part is provided on a lower surface of the protrusion. The rotary plating apparatus according to claim 4,
A rotary plating apparatus characterized in that a plurality of the air blowing parts are provided on the lower surface of the protruding part at predetermined intervals in the circumferential direction. The rotary plating apparatus according to claim 3,
The cap base has a protruding part that protrudes outward from the anode bag, and the air blowing part is provided in an annular shape between the protruding part and the cap cover. Mold plating equipment.