JP2018178181A - Electronic component plating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component plating device capable of reducing plating failures of a plating film of an electronic component by efficiently discharging plating liquid from a plating tank.SOLUTION: A plating tank 15 can rotate in a horizontal direction, and stores a plated object 25 and plating liquid in an internal space formed of an approximately conical lid part 11 and an approximately disk-like bottom 13 including an outer peripheral sidewall 28. Narrowing of the plated object 25, its residues and the like are prevented by providing an opening 20 in a position with which the plated object does not directly come into contact in an inclined side surface 11a of the lid part 11 even when a plating layer rotates. This makes it possible to efficiently and surely discharge only plating liquid and washing water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plating apparatus for an electronic component, for example, for plating an electrode or the like of a chip type electronic component.

  Small electronic components such as chip resistors are plated to form external electrodes in order to improve the solderability to the circuit board and ensure electrical continuity. As a plating apparatus for forming such an external electrode, for example, an object to be plated and a plating solution are placed in a plating tank, and the plating tank is horizontally alternated horizontally (forward and reverse) alternately or continuously or intermittently. There is known an apparatus for rotating and plating.

  In such a plating apparatus, since the metal concentration in the plating tank is gradually decreased by the electrolytic reaction, the plating solution is always circulated between the plating tank and a separately provided mother tank.

  For example, in Patent Document 1, the rotational speed of the plating treatment chamber changes in order to prevent aggregation of the object to be plated and the conductive medium by centrifugal force in the plating treatment chamber configured to be rotatable. A method of plating while rotating continuously or intermittently in an aspect is disclosed. Furthermore, the plating apparatus of Patent Document 1 includes an annular plating extraction portion (porous ring) made of a porous material that can extract and discharge only the plating solution to the outside without letting the object to be plated pass through. The extracted plating solution is circulated through the circulation path to the plating treatment chamber.

  Further, in Patent Document 2, a plating processing chamber for containing a material to be plated, etc. has a rotary member having an opening at the top and a cathode provided on the outer peripheral portion, and a cylindrical member arranged at the center of the rotary member. And an anode disposed inside the rotating body, and causing the plating solution to flow into the tubular member by causing the tubular member to overflow and allow the plating solution to flow back to the plating treatment chamber from the opening. A plating apparatus for circulating a solution is disclosed.

Unexamined-Japanese-Patent No. 2006-045619 (patent 4725051) gazette Unexamined-Japanese-Patent No. 2013-053339 (patent 5741944) gazette

  In the discharge method for the circulation of the plating solution in Patent Document 1, as described above, the annular plating extraction portion made of porous material, which is set on the base member (bottom) of the plating tank together with the cathode electrode, And the material to be plated does not pass through, and plays the role of a filter (porous ring filter).

  However, in the case of a porous filter in which minute holes of several μm to several mm have been opened innumerably in recent years, miniaturization of electronic parts which are objects to be plated of a plating apparatus is progressing. A lot of media etc. are caught. Therefore, the plating solution does not circulate in the plating apparatus, which may cause problems such as non-plating. In addition, there is a problem that the plated material once caught in the filter falls off, and problems such as non-plating and abnormal plating frequently occur. In addition, it is possible that the plated material is gradually plated to close minute holes, making it difficult to circulate and discharge the plating solution itself and not to function as a plating apparatus in a short time. .

  In addition, as in the plating apparatus of Patent Document 2, a configuration in which the plating solution is made to overflow the cylindrical member provided at the center of the rotating body, flowed into and discharged from the cylindrical member, and returned to the plating treatment chamber However, the small size of the electronic component to be plated causes floating on the liquid surface due to buoyancy, and there is a problem that the electronic component is also discharged together with the discharge of the plating solution.

  The present invention has been made in view of the above-described problems, and by efficiently discharging the plating solution from the plating tank, it is an electron that reduces plating defects such as thickness variations of a plating film formed on a chip-like electronic component. An object of the present invention is to provide a plating apparatus for parts.

  As means for achieving the object and solving the above-mentioned problems, for example, the following configuration is provided. That is, in the plating apparatus for electronic parts of the present invention, the object to be plated and the plating solution are stored in the internal space formed by the substantially conical lid portion and the substantially disc-like bottom portion having the outer peripheral side wall. A rotatable plating tank, an anode electrode disposed substantially at the center of the plating tank, a cathode electrode exposed on the inner peripheral side of the plating tank and constituting a part of the outer peripheral side wall, the lid And an opening for discharging the plating solution provided in the part.

  For example, a plurality of the opening portions may be provided at intervals in the circumferential direction of the lower portion of the lid portion. For example, the lower portion of the lid provided with the opening is characterized in that the object to be plated does not reach when the plating tank is rotated. Further, for example, by changing the height of the outer peripheral side wall, the vertical position of the opening in the plating tank can be adjusted.

  Furthermore, for example, the opening is a through hole provided in a lower portion of the inclined side surface of the lid. Further, for example, the opening portion is characterized in that a cylindrical member which protrudes to the outside of the lid portion is inserted into a through hole provided in a lower portion of the inclined side surface of the lid portion. Furthermore, for example, the opening portion is formed by inserting a tubular member protruding to the outside of the lid portion into a through hole provided in a lower portion of the inclined side surface of the lid portion and providing a net-like member covering the through hole. It is characterized by

  According to the present invention, by providing the opening at a position where the object to be plated does not come into direct contact when the plating tank rotates, pinching and remaining of the object to be plated can be prevented, and circulation and discharge of the plating solution and washing water are possible. A uniform plating process can be performed on the object without any problems.

It is a perspective view which fractures a part of plating device of electronic parts concerning an example of an embodiment of the present invention, and shows the structure. It is sectional drawing which was provided in the cover part of the plating tank of the plating apparatus which concerns on the example of this Embodiment, and which shows the detailed structure of the opening part for a plating solution discharge. It is a figure which shows the other structural example of the opening part provided in the cover part of the plating tank. It is a figure which shows the example of arrangement | positioning of the opening part provided in the cover part of the plating tank which concerns on the example of this Embodiment. It is a figure which shows typically the circulation route, such as a plating solution in the plating apparatus which concerns on the example of this Embodiment. It is a figure which shows the cross-sectional structure of the chip-like resistor in which the plating layer was formed in the exterior electrode.

  Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings and the like. FIG. 1 is a perspective view showing a structure in which a part of a plating apparatus for electronic parts according to the present embodiment is broken. The plating apparatus 10 shown in FIG. 1 is a rotary type in which an internal space constituted by a lid portion 11 having a substantially conical outer shape and a bottom portion 13 disposed on the bottom surface side of the lid portion 11 is a plating tank 15. It is a plating apparatus (dome type plating apparatus).

  The lid portion 11 has a protrusion 26 in which the peripheral portion (the outermost peripheral portion) of the lowermost end of the inclined side surface protrudes like a hook in the outer peripheral direction, and the protrusion 26 is covered by an annular ring member 29 There is. Further, an opening 20 for discharging a plating solution or the like stored in the plating tank 15 is provided below the inclined side surface of the lid 11. The details of the opening 20 will be described later.

  The bottom portion 13 is disposed along a disk-shaped bottom plate (base member) 18 having the same outer diameter as the outer diameter of the outermost peripheral portion of the lid portion 11 and an outer peripheral edge on the upper surface side of the bottom plate 18 A spacer which is an annular member located at the upper part of the ring-shaped cathode electrode (cathode contact) 17 having the following width and the cathode electrode 17 and below the projection 26 of the lid 11 and having the same diameter as the cathode electrode 17 And a ring 19. In the plating tank 15, an outer peripheral side wall 28 is formed by the outer peripheral edge portion of the bottom plate 18, the cathode electrode 17, the spacer ring 19, and the protrusion 26.

  The ring member 29, the protrusion 26, the spacer ring 19, and the cathode electrode 17 are provided with a plurality of through holes in the circumferential direction. Then, the fixing member 27 is inserted into the through hole in a state in which these are superimposed, and the male screw portion provided at the tip of the fixing member 27 and the female screw portion provided on the bottom plate 18 are screwed together, The lid 11 and the bottom 13 are fixed to each other. An internal space formed by the lid 11 and the bottom 13 is a plating tank 15.

  The spacer ring 19 can be removed from the plating tank 15 by releasing the screwing by the fixing member 27. Therefore, the height of the outer peripheral side wall 28 described above can be changed by preparing the spacer rings 19 having different thicknesses in accordance with the input conditions of the product (object to be plated) in the plating apparatus 10 and the like. The volume of the plating tank 15, the position of the opening 20 (height from the bottom plate 18), and the like can be adjusted. Furthermore, the drainage capacity of the plating tank 15 can also be adjusted by appropriately setting the size and the number of the openings 20.

  An anodic electrode 16 to be immersed in the plating solution is disposed at the center of the plating tank 15, and washing water is introduced through the upper opening 24 provided at the top of the lid 11 to the center of the plating tank 15. A pipe 21, a treatment liquid introduction pipe 22, and a liquid level sensor 23 for detecting the amount of plating solution in the tank are provided. In the plating apparatus 10, as described later, circulation and discharge of various processing solutions are efficiently performed by the washing water introducing pipe 21, the processing solution introducing pipe 22, and the like.

  A vertically downwardly extending rotary shaft 12 is coupled to the lower surface side central portion of the bottom portion 13, and the rotary shaft 12 is rotatably supported. Here, the rotational force is applied to the rotating shaft 12 by a motor or the like (not shown), whereby the object 25 to be plated such as an electronic component and the plating tank 15 in which the plating solution (not shown) is stored are horizontal. To rotate. Specifically, as shown by the white arrow in FIG. 1, the plating tank 15 repeatedly rotates and stops at a predetermined speed by rotation in the clockwise direction and counterclockwise direction (forward and reverse direction). The rotating shaft 12 is connected from the negative side of the electrolytic plating power supply, and a conductive member 14 for supplying current to the cathode electrode 17 is in contact.

The plating tank 15 alternately repeats forward and reverse rotation in the horizontal direction, and the rotation is maintained, and as shown in FIG. 1, the anode is only pressed for a short time when the object to be plated is pressed against the cathode electrode 17 by centrifugal force. processing Ki Tsu because is energized between electrode 16 and the cathode electrode 17 is performed.

  The object to be plated by the plating apparatus of the electronic component according to the present embodiment is not limited to a chip type resistor, and for example, a chip type inductor, a chip type capacitor, a composite component thereof, multiple resistors, etc. It can also be used for the plating process of the electronic component which has an electrode terminal.

  FIG. 2 is a cross-sectional view showing the detailed structure of the opening for discharging the plating solution, provided in the lid of the plating tank in the plating apparatus according to this embodiment. As shown in FIG. 2, the opening 20 is a lower portion of the inclined side surface 11 a of the lid 11, and is a through hole provided at a position where the object to be plated 25 does not directly contact when the plating tank 15 rotates in the horizontal direction. It consists of 33. Here, the hole diameter D of the opening 20 is, for example, 3 mm or more, but is not limited thereto.

  The liquid level (liquid level) of the plating solution 30 in the plating tank 15 is the plating tank when the plating tank 15 is stationary before the plating treatment or immediately after the plating treatment, etc., and during the plating treatment or during the washing treatment When 15 is rotating, it is located near the upper opening 24 of the plating tank 15 (liquid level 31 a in FIG. 2). At this time, the plating solution 30 is discharged from the opening 20 to the outside of the plating tank 15. However, since a new plating solution is supplied to the plating tank 15 through the treatment solution introduction pipe 22 by the circulation route described later There is no change in the position of the surface 31a. On the other hand, at the stage of completion of the plating process and the like and dehydration (discharge), the plating solution 30 is discharged from the opening 20 to the outside, and the supply of the plating solution from the processing solution introduction pipe 22 is stopped. Drops to near the upper surface of the bottom plate 18 (liquid level 31 b in FIG. 2).

  In addition, although the opening part 20 is comprised only by the through-hole 33 formed in the cover part 11 in the example shown in FIG. 2, it is not limited to this. For example, as in the opening 20a shown in FIG. 3A, a hollow pipe (tube) 35 having a hole diameter D of, for example, 3 mm and made of metal or fluorine resin is attached to the through hole 33. For example, H = 3 to 5 mm may be protruded outside the lid 11. Thus, even if the plating object 25 comes in contact with the lower end of the through hole 33 and jumps out when the plating tank 15 rotates, the plating object is captured by the hollow pipe 35 having a predetermined length, and Since the hollow pipe 35 is made of a material having a low coefficient of friction and is inclined, the captured object to be plated is returned again into the plating tank 15, so the outside of the plating tank for the object to be plated is not reduced Can be effectively prevented. Further, by projecting the hollow pipe 35 to the outside of the lid portion 11, the hollow pipe can be easily pulled out, for example, when replacing the hollow pipe.

  On the other hand, the opening 20b shown in FIG. 3 (b) is configured such that the through hole 33 is covered with the net-like member 37 inside the lid 11 with respect to the opening 20a shown in FIG. 3 (a) . The net-like member 37 is made of, for example, a fluorine resin or the like, and allows the plating solution to easily pass through, but has a mesh of such a degree as not passing fine objects to be plated of 1 mm or less. As a result, even if the object 25 comes in contact with the opening of the through hole 33, the net-like member 37 prevents entry into the pipe 35, so that the object to be plated is scattered outside the plating tank 15. Can be reliably prevented.

  That is, as shown in FIG. 3B, by providing the opening portion 20b in which the net-like member 37 is stretched in the through hole 33 in the lid portion 11 of the plating tank 15, floating objects of the object 25 to be plated It is possible to prevent the leaked product etc. from leaking out of the plating tank 15 together with the plating solution.

  In the case of producing the opening 20b shown in FIG. 3B, a net-like member 37 having a size exceeding the diameter of the through hole 33 is prepared, and the net-like member 37 is The hollow pipe 35 is inserted into the through hole 33 together with the net-like member 37 while being in contact with the outside of the By doing this, it is possible to stretch the net so as to cover the entire through hole 33 without exposing the end of the net-like member 37 to the inside of the plating tank 15. Further, by pulling out the hollow pipe 35 from the through hole 33, the net-like member 37 can be easily replaced.

  FIG. 4 shows an arrangement example of the openings provided in the lid when the plating tank of the plating apparatus according to this embodiment is viewed in plan. FIG. 4A shows an example in which a plurality of openings 20 are provided at equal intervals in the circumferential direction on the lower side of the inclined side surface of the lid 11. Further, FIG. 4B shows an example in which a plurality of openings 20 are provided in the circumferential direction on the lower side of the inclined side surface of the lid 11 so as to be symmetrical with respect to the center line 41. The hole shape of the opening 20 may be either circular or oval.

  In the example shown in FIG. 4A, the six openings 20 are arranged at equal intervals, but, for example, the number of openings may be increased or decreased according to the size of the plating tank, the amount of drainage required, etc. It may be arranged at random intervals. In addition, a plurality of lids may be prepared in which the hole diameter of the openings, the number of the openings, and the distance between the openings are appropriately changed according to the size of the plating target and the input amount.

  FIG. 5 schematically shows a circulation route of a plating solution or the like in the plating apparatus according to the present embodiment. In the plating apparatus 10 shown in FIG. 5, when the plating solution is discharged from the opening 20 provided in the lid 11 as the plating tank 15 rotates, new plating solution in the plating solution mother tank 51 is introduced with the treatment solution at the same time. It is supplied to the plating tank 15 via the pipe 22. Further, the plating solution discharged from the opening 20 is received by the container 50 which covers the entire exterior of the plating tank 15 and reaches the plating solution mother tank 51 via the treatment solution outlet pipe 42.

  At the time of discharge of the processing solution due to the change of the plating type in the plating apparatus 10, the plating tank 15 is rotated at high speed in a predetermined direction, and the plating solution etc. is discharged from the opening 20 using the centrifugal force at that time. Receive at 50

  In the step of washing the plating material, the washing water is supplied from the washing water tank 53 into the plating tank 15 through the washing water introduction pipe 21 and the discharge of the washing water after the washing is also the plating tank as in the case of discharging the treatment liquid. The rotation is performed at high speed using its centrifugal force. Then, the flush water received by the container 50 is returned to the flush tank 53 through the flush water outlet pipe 41.

  Since the metal concentration in the plating tank 15 gradually decreases due to the electrolytic reaction in the plating treatment in the plating apparatus 10, circulation of the plating solution is always performed between the plating tank 15 and the plating solution mother tank 51 provided separately. It will be. Therefore, when the treatment liquid and the washing water are not circulated or discharged with certainty, various problems of the plating quality occur due to abnormal current at the time of plating, mixing of each treatment liquid, and the like.

  Next, the evaluation results of the plating quality of the chip resistor plated using the plating apparatus according to the present embodiment will be described with reference to examples. Here, the film thickness (μm) of the Ni (nickel) plating layer and the film thickness (μm) of the Sn (tin) plating layer were measured for the lots of Examples 1 to 5 shown in Table 1. The film thickness of each plating layer was measured at a sample number n = 20.

  The Ni plating layer and the Sn plating layer are two plating layers that constitute the external electrode in the chip resistor having the cross-sectional structure illustrated in FIG. 6, and generally, the end surface electrode is formed in the manufacturing process of the chip resistor. Thereafter, a Ni plating layer is formed, and the Ni plating layer is overlaid and subjected to Sn plating to form a Sn plating layer.

  The plating solution used to form the plating layer of the chip resistor in the plating process is Ni plating: Watt bath, Sn plating: neutral bath. Further, the object to be plated is a 0603 size resistance chip and φ0.55 mm medium for energization.

  In the trial production example using the conventional plating apparatus, about 20-30 pieces of the remaining number after pinching | pinching of the to-be-plated thing in the plating tank (porous ring) and the water washing were confirmed. On the other hand, in the trial manufacture example (Examples 1-5 of Table 1) of the chip resistor which carried out the plating process using the plating apparatus which concerns on the example of this Embodiment, the pinch etc. of a thing to be plated are 0 pieces. The Moreover, in the trial production example using the conventional plating apparatus, although many non-plated products (plating non-adhered products) that are considered to be caused by the pinching to the porous ring were seen, the plating according to the present embodiment example In the trial production example using the apparatus, there is no unplated product, and further, since the difference between the maximum value and the minimum value of the film thickness is small, good results are obtained also for the film thickness variation of the plating.

  As described above, in the plating apparatus of the electronic component according to the present embodiment, among the inclined side surfaces of the lid constituting the plating layer, at a position where the object to be plated does not directly contact even if the plating layer rotates. By providing the opening, the object to be plated can be prevented from being pinched, remaining, etc., and only the plating solution and the washing water can be discharged efficiently and reliably. That is, even if the plating tank is rotated in the horizontal direction and the material to be plated is moved to the end of the plating tank by centrifugal force and pressed against the inner wall, the opening is provided at a position not overlapping with the material to be plated Thus, the object can be uniformly plated without affecting the circulation and discharge of the plating solution and the like.

  In addition, by changing the thickness of the spacer ring that constitutes the bottom of the plating layer to adjust the height of the outer peripheral side wall, the verticality of the opening in the plating tank can be adjusted according to the input conditions of the object to be plated, etc. The position of the direction and the volume of the plating tank can be adjusted quickly.

  Furthermore, the plating apparatus for electronic parts according to the present embodiment provided with the opening as described above does not require a strong structure and attachment like the conventional porous filter ring, and the structure of the plating apparatus is simplified. Not only that, it is possible to efficiently circulate and discharge the processing solution, and it is possible to reliably prevent the occurrence of abnormal plating quality with a simple configuration.

  Moreover, when it is set as the opening part of the structure which stretched the net-like member to the through-hole inside the cover part of the plating tank, periodic maintenance, such as net replacement | exchange, can also be performed simply and easily for a short time.

DESCRIPTION OF SYMBOLS 10 Plating apparatus 11 Cover part 12 Rotary shaft 13 Bottom part 14 Conduction member 15 Plating tank 16 Anode electrode 17 Cathode electrode 18 Bottom plate (base member)
19 spacer ring 20, 20a, 20b opening 21 washing water introduction pipe 22 treatment liquid introduction pipe 23 liquid level sensor 24 upper opening 25 to be plated 26 projection 27 fixed member 28 outer peripheral side wall 29 ring member 30 plating liquid 31 liquid surface (Liquid level)
33 through hole 35 hollow pipe 37 net-like member 41 flush water outlet pipe 42 treatment liquid outlet pipe 50 container 51 plating solution mother tank 53 flush water tank

Claims (7)

A plating tank capable of storing an object to be plated and a plating solution in an internal space formed by a substantially conical lid portion and a substantially disc-like bottom portion having outer peripheral side walls, and capable of rotating in the horizontal direction;
An anode electrode disposed substantially at the center of the plating tank;
A cathode electrode exposed on the inner peripheral side of the plating tank and constituting a part of the outer peripheral side wall;
An opening for discharging a plating solution provided in the lid;
An apparatus for plating electronic parts, comprising: The plating apparatus according to claim 1, wherein a plurality of the opening portions are provided at intervals in a circumferential direction of a lower portion of the lid portion. The plating apparatus according to claim 2, wherein a lower portion of the lid provided with the opening is a portion to which the object to be plated does not reach when the plating tank is rotated. The apparatus according to claim 3, wherein the vertical position of the opening in the plating tank is adjustable by changing the height of the outer peripheral side wall. The said opening part is a through-hole provided in the inclined side lower part of the said cover part, The metal-plating apparatus of the electronic component of any one of Claim 1 to 4 characterized by the above-mentioned. The said opening part inserts the cylindrical member which protrudes in the outer side of this cover part in the through-hole provided in the inclined side lower part of the said cover part, It is characterized by the above-mentioned. The plating apparatus of the electronic component as described in a term. The opening has a net-like member for inserting a cylindrical member projecting to the outside of the lid into the through hole provided in the lower part of the inclined side surface of the lid and covering the through hole. The plating apparatus of the electronic component of any one of Claim 1 to 4 made into any one.