JPH0730453B2 - Method and apparatus for partial plating of ceramic package - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for plating a ceramic package, and more particularly to a partial plating method and apparatus for plating a noble metal such as gold only on the surface to be plated. Here, the ceramic package 1 shown in FIG. 5 has a mount portion 5 composed of a sealing portion 2, a lead portion 3 and a die pad portion 4 which are formed stepwise, and side lead portions 6 on both sides.
Are provided, and the mount portion 5 is the surface portion to be plated.

The term "plating" used in this specification means "electrolytic plating".
Alternatively, either "electroless plating" may be used.

<Prior Art> Conventionally, as a plating method of a ceramic package, for example, a rack plating method, and as a partial plating method thereof, a megisto seal method or a mechanical masking method (module mask; Nippon Electroplating Engineering Co., Ltd.) The company's registered trademark) etc. are known.

<Problems to be Solved by the Invention> However, in the rack plating method, although the plating process itself is simple and easy, unnecessary portions (specifically, the side lead portions 6) are also plated. It is insufficient in that expensive plating material such as gold is wasted, and the resist sealing method is inferior in workability because the resist processing work is difficult, and the mechanical sealing method is , The characteristics of the ceramic package 1,
That is, since the space between the mount portion 5 and the side lead portion 6 is very narrow (usually 1 mm or less), a sufficient sealing space cannot be taken for this portion, so reliable sealing cannot be performed, and eventually, However, it is necessary to remove the plating of the unnecessary portion caused by the seal leakage, resulting in insufficient economic efficiency and workability.

Therefore, it is an object of the present invention to provide a partial plating method for a ceramic package and a device therefor which can reliably and accurately perform plating on the surface to be plated accurately and quickly.

<Means for Solving Problems> As means for achieving the above-mentioned object, in the first invention [the invention according to claim (1), the same applies hereinafter], an overflow type plating solution in which a plating solution is sprayed is used. The liquid is supplied into the plating tank and discharged and collected from this plating tank while maintaining a predetermined liquid level, and the surface of the ceramic package to be plated is brought into contact with the plating liquid while being inclined with respect to the liquid surface. In the second invention [the invention described in claim (2), the same applies hereinafter], the plating solution supplied to the plating apparatus in an injection state is kept at a predetermined liquid level by an overflow weir. While providing a plating tank to be discharged and an upper lid arranged in an inclined state with respect to the liquid surface of the plating liquid, the first metal corresponding to the surface to be plated of the ceramic package that is the object to be plated. A masking pad having a kick opening and a plurality of first through-holes, one end of which faces the first plating opening, is attached to the upper surface of the upper lid, and the second lid has a second plating opening communicating with the first plating opening. The gist is to provide a plurality of second through holes, one end of which communicates with each of the first passages and the other end of which faces the plating tank.

<Operation> That is, since the plating solution is constantly supplied with sufficient agitation by being supplied into the overflow-type plating treatment tank in a jet state, it is possible to obtain conditions suitable for accurate and rapid plating, and at the same time, to perform plating. The liquid can be discharged and collected from this overflow type plating treatment tank while maintaining a predetermined liquid level, and the plating target surface portion is brought into contact with the plating liquid in a state of being inclined with respect to the liquid surface. Since the stirring pressure is prevented from unnecessarily reaching the surface to be plated depending on the condition, a sufficient sealing effect can be obtained even with a small sealing space (first invention, second invention). .

Further, the masking pad and the upper lid on which the masking pad is mounted are each provided with first and second through holes communicating with each other, and one end of the first through hole is exposed to the first plating opening and at the same time the second through hole is formed. Since the other end of the through hole is exposed to the inside of the plating tank, the plating solution circulates through both of these through holes, and the stirring effect extends to every unevenness (step) of the surface to be plated. By this circulation, it is possible to eliminate bubbles that tend to stay in the corners of unevenness (steps), and it is possible to perform more rapid and accurate plating (second invention).

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. In the following description, the second invention will be the main subject,
The first invention will be appropriately referred to.

In this ceramic package partial plating apparatus 10, an overflow type plating treatment tank 11, a collection tank 13 for collecting the plating solution 12 discharged from the plating processing 11, and an upper lid 14 for covering both tanks 11, 13 are provided. A sparger 15 is provided.

The plating treatment tank 11 is provided with an injector 19 at its bottom portion 18 that is inclined with respect to the liquid surface 16 of the plating liquid 12, and the plating treatment tank 11 and the injector 19 are connected by an injection nozzle 20 and a plurality of nozzles. This is done via an anodized injection plate 22 with auxiliary injection holes 21. Here, a plurality of auxiliary injection holes 21 are provided together with the injection nozzle 20 projecting on the injection plate 22, and the combination of the two makes it possible to efficiently agitate the plating solution 12, so to speak, three-dimensionally efficiently. Twenty tip openings are 15 to 50 mm from mount 5 (surface to be plated)
And, it is far apart from 3 to 12 mm in the case of normal jet plating. This is similar to the setting of the inclination of the mount portion 5 (plating target surface portion) with respect to the plating liquid surface 16 which will be described later. Masking pad between
It has a function of preventing 28 from reaching the sealed portion. In addition, providing a plurality of auxiliary injection holes 21
Supply of plating solution 12 to plating tank 11 or plating tank
It is also useful in that it can be quickly discharged from 11.
The injection nozzle 20 is selectively anodized according to the requirements of individual plating conditions.

The recovery tank 13 is on the upper side (A side) of the plating processing tank 11 in the inclined state.
The overflow weir 24 provided at the upper end of the slope of the plating treatment tank 11 collects the plating liquid 12 to be discharged while maintaining a predetermined liquid level and returns it to the storage tank 25. Here, the "predetermined liquid surface level" means the mounting portion 5 of the ceramic package 1 in the state as shown in FIG.
It means a state where the whole (surface to be plated) can contact the plating solution 16, that is, a liquid level above the upper end of the mount 5 (surface to be plated), preferably a few mm higher than this upper end.

The upper lid 14 has a first plating opening 26 corresponding to the mount portion 5.
And a plurality of first platings, one end of which faces the first plating opening 26.
The mound part 5 of the ceramic package 1 is provided with a through hole 27.
A masking pad 28 for sealing the other components from the plating liquid 12 is attached, and a second plating opening 29 communicating with the first plating opening 26 and one end communicating with each first through hole 27 and the other end inside the plating treatment tank 11 A plurality of second through holes 30 facing each other are provided. Moreover, the upper lid 14 is arranged in parallel with the bottom portion 18 of the plating treatment tank 11 and is also inclined with respect to the liquid surface 16 of the plating liquid 12. Top cover for plating surface 16 of plating solution 12
The inclination angle Θ of 14 is 5 ° to 45 °. In this embodiment, the first and second through holes 27 and 30 are provided on both sides of the first and second plating openings 26 and 29, respectively.
It may be provided only on. However, in view of the bubble discharging function of both through holes 27, 30 as described later, the second through hole 30 on the upper side (A side) is in a horizontal or upward rising state in FIG. 1 so that bubbles can be easily discharged. It is even more preferable to be provided as. Further, the shape of the first plating opening 26 of the masking pad 13 is a cone shape that widens toward the contact side with the ceramic package 1. However, with such a shape, the sealing portion 2 of the mount portion 5 This is preferable in that the plating thickness can be prevented from becoming thicker than the plating thickness of the lead portion 3 to the die pad portion 4, but the plating thickness is not necessarily limited to this, and may be, for example, a direct shape as shown in FIG. .

In the figure, 32 is a pump and 33 is a rectifier. Further, 36 is a vent hole for making the inside of the plating tank 11 parallel to the atmospheric pressure.

The operating state of the partial plating apparatus 10 for this ceramic package will be described below.

The plating liquid 12 is sent from the liquid storage tank 25 by the pump 32, and is supplied to the plating treatment tank 11 in an injection state via the injection body 19. The plating solution 12 thus supplied to the plating treatment tank 11
Is discharged to the recovery tank 13 while maintaining a predetermined liquid level at the overflow weir 24. Then, the ceramic package 1 as an object to be plated has the first plating opening.
By mounting the mount portion 5 on the 26 and pressing it from the direction B shown by the arrow by pressing means (not shown), it is set on the upper lid 14, specifically, on the mating pad 28,
While being inclined with respect to the liquid surface 16 of the plating liquid 12, it is sealed by a masking pad 28, and only the mount portion 5 is brought into contact with the plating liquid 12 for partial plating.
At this time, the unevenness (steps) on the mount 5 has a subtle influence on the plating state, and at the same time, the bubbles attached to the mount 5 or the bubbles generated by the plating tend to stay at the corners of the unevenness (steps). However, since the plating solution 12 circulates through the masking pad 28 and the first and second through holes 27, 30 of the upper lid 14, the stirring effect up to every corner of the unevenness (steps) is well distributed. It is possible to suppress the delicate influence of (steps), and by this circulation, it is possible to eliminate bubbles that stay at the corners of the bumps (steps).

In this way, since the plating solution 12 is always given sufficient agitation, conditions suitable for accurate and speedy plating can be obtained, and at the same time, the agitation pressure depending on the jetting state is unnecessarily high. Since the masking pad 28 does not extend between the mount portion 5 and the side lead portion 6 to the sealed portion, a sufficient sealing effect can be obtained even with a small sealing space. Become. One specific numerical example of rapid plating conditions is 1-3A.
/ current density dm ² becomes possible, and the point that has become a normal was very Xiu than a rack plating method that can not be given only a current density of 0.25A / dm ^2. In addition, the first and second through holes 27, 30 allow the stirring effect to reach even the corners of the unevenness (steps) of the mount portion 5 and eliminate bubbles that tend to stay in the corners of the unevenness (steps). Therefore, the plating can be performed more quickly and accurately.

FIG. 6 shows another embodiment. This embodiment has a second through hole
A sub through hole 34 connected to 30 is provided, and air is blown from the sub through hole 34 to the mount portion 5 through the second through hole 30, and after the plating solution 12 is discharged from the plating treatment tank 11, the mount portion 5 is also removed. The feature is that the plating liquid 12 adhering to the is removed, and the amount of dragout (takeout of the plating liquid to the recovery process) is minimized. In the figure, 35 is
It is a pin for positioning the ceramic package 1. The other points are the same as those of the above-described embodiment, and the description thereof is omitted.

<Effect of the Invention> As described above, according to the present invention, the supply and the overflow (discharging) depending on the injection state are combined, and the surface to be plated is brought into contact with the plating liquid by making the surface inclined with respect to the liquid surface of the plating liquid. Since these three conditions are organically cooperated to form a delicately balanced plating condition, it is excellent because it has a sealing property and can accurately and promptly perform partial plating of a ceramic package. It is effective (first invention, second invention).

In addition, the masking pad and the upper lid are provided with first and second through holes that communicate with each other, and the circulation of the plating solution through these through holes has a stirring effect even on the unevenness of the surface to be plated. In addition to making it possible to extend, this environment is to eliminate bubbles that tend to stay in the uneven corners,
There is also an excellent effect that more accurate and quick plating can be performed (second invention).

[Brief description of drawings]

1 is a schematic side view showing an essential part of a partial plating apparatus for a ceramic package according to an embodiment of the second invention, FIG. 2 is a schematic perspective view of a masking pad, and FIG. 3 is a schematic perspective view of FIG. Sectional drawing along the arrow III-III line, FIG. 4 is a sectional view along the arrow IV-IV line in FIG. 2, FIG. 5 is a schematic perspective view of the ceramic package, and FIG. FIG. 7 is a schematic side sectional view showing an essential part of a partial plating apparatus for a ceramic package according to this embodiment, and FIG. 7 is a schematic sectional view of a masking pad according to another embodiment. 1 …… ceramic package 5 …… mount part (screen to be plated), 10 …… partial plating device for ceramic package 11 …… plating tank 12 …… plating solution 13 …… collection tank 14 …… top cover 16 …… liquid level 24 …… Overflow weir 26 …… First plating opening 27 …… First through hole 28 …… Masking pad 29 …… Second plating opening 30 …… Second through hole

Claims (2)

[Claims] 1. A plating solution is supplied into an overflow-type plating treatment tank in a jet state, and is discharged and collected from the plating treatment tank while maintaining a predetermined liquid level, and a surface of a ceramic package to be plated is covered. A method for partially plating a ceramic package, which is brought into contact with a plating solution while being inclined with respect to the liquid surface. 2. A plating treatment tank for discharging a plating solution supplied in an injection state at an overflow weir while maintaining a predetermined liquid level, and an upper lid arranged in an inclined state with respect to the liquid level of the plating solution. A masking pad having a first plating opening corresponding to a surface to be plated of a ceramic package, which is an object to be plated, and a plurality of first through holes exposing one end to the first plating opening is mounted on the upper surface of the upper lid; This top cover has the first
A partial plating apparatus for a ceramic package having a second plating opening communicating with the plating opening and a plurality of second through holes communicating one end with each of the first through holes and exposing the other end into the plating tank.