JP3339926B2 - Partial plating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial plating apparatus.

[0002]

2. Description of the Related Art In a lead frame for a semiconductor device, a plating film for fixing a semiconductor element and a wire bonding, for example, a silver plating film are formed on an element mounting portion (stage) and a tip of an inner lead, respectively. This plating film is applied by a partial plating apparatus called jet plating. FIG. 6 shows an example of the partial plating apparatus. Reference numeral 10 denotes a sparger, which has a closed box shape. Reference numeral 12 denotes a mask, which has an opening at a portion corresponding to a plating area of the lead frame 14 as an object to be plated, and presses the lead frame 14 between itself and the plate 16.
Reference numeral 18 denotes a plating solution supply container, which is disposed in the sparger 10, and a nozzle plate 20 is disposed on the front side thereof. Reference numeral 22 denotes a baffle plate traversed in the plating solution supply container 18 and is formed with a through hole 24 through which the plating solution flows back and forth. The plating solution is introduced from the tank 26 into the plating solution supply container 18 by the pump 28, is ejected from the nozzle 30 provided on the nozzle plate 20, and is ejected from the opening of the mask 12 to a predetermined portion of the lead frame 14. Reference numeral 32 denotes a platinum wire serving as an anode, which is extended near the tip of the nozzle 30. As shown in FIG. 7, the nozzle plate 20 is formed by fixing a vinyl chloride cylinder to a through hole provided in a vinyl chloride plate and forming the nozzle 30 in a plurality of units. A predetermined number of lead frames are provided corresponding to each unit lead frame of the lead frame 14 to which the lead frames are connected. The platinum wire 32 is supported and stretched by a grooved support frame 34.

[0003]

The above conventional partial plating apparatus has the following problems. That is, recently, the lead frame is formed in a fine pattern by increasing the density of the semiconductor element. In particular, apart from the signal leads, a plurality of power supply leads and ground leads are set at other positions not in the same row as the tip of the inner lead. As a result, the shape and structure have become complicated, and instead of simply a rectangular plating region as in the past, a plating region having a complicated complexity has appeared. When the plating solution is ejected to the plating region having such a complicated shape by the conventional cylindrically projecting nozzle 30, the plating solution cannot be ejected evenly over the entire plating region, and the plating film having a uniform thickness is formed. Is difficult to obtain. It is considered that the disposition position of the nozzle 30 should be changed corresponding to a complicated plating area. However, the nozzle 3 may have a cylindrical shape due to the relationship with the platinum wire 32 or the like.
There is a situation that it is difficult to freely arrange zeros. There is also a problem that the platinum wire 32 is expensive.

Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a uniform plating film which can sufficiently cope with a complicated plating area and is inexpensive. It is an object of the present invention to provide a partial plating apparatus which can be formed on a substrate.

[0005]

The present invention has the following arrangement to achieve the above object. In other words, the object to be plated Der
In a partial plating apparatus for covering a lead frame with a mask and spraying a plating solution from a nozzle into an opening of the mask to perform plating on a plating region of an object to be plated corresponding to the opening, the nozzle includes a lead frame. Plating area
An ejection hole arranged to eject a plating liquid corresponding to a stage and / or an inner lead ,
And an auxiliary electrode projecting toward the lead frame.
A metal plate, and using the metal plate as an anode. It is preferable that the ejection hole is formed in a plurality of through holes having the same shape. It is preferable that the metal plate is made of stainless steel. In addition, the ejection hole
A tapered chamfer is formed at the edge on the mask side
Is preferred.

[0006]

The operation of the present invention will be described with reference to FIGS. The pump 28 pumps up the plating solution in the tank 26, pumps the plating solution into the plating solution supply container 18, and ejects the plating solution from the ejection holes 38 to the plating area of the lead frame 14 surrounded by the mask 12, thereby forming a lead frame. 14
Stage and / or the inner leads can be partially plated. In this case, since the nozzle plate 36 itself, which is a metal plate, is used as the anode, a large current density can be obtained, and the plating time can be shortened. In addition,
By providing the auxiliary electrode, the current density is increased and the plating
Can be improved. Further, as shown in FIG. 2, the nozzle plate 36 is provided with an ejection hole 38, and the ejection hole 38 is provided on a stage and / or
The plating solution can be freely arranged at an arbitrary position of the nozzle plate 36 corresponding to the inner lead , the plating solution can be jetted uniformly even in a complicated plating area, and a plating film having a uniform thickness can be obtained. By making the ejection holes 38 have the same shape, the flow velocity of the plating solution to be ejected can be made the same, and thereby the plating thickness can be made uniform. Also nozzle plate 3
6 can be formed inexpensively by using a stainless steel plate. In addition, a tapered edge on the mask side of the
By forming a round chamfer, the jetting angle of the plating solution
Can be adjusted.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 10 denotes a sparger, 12 denotes a mask thereof, 14 denotes a lead frame as an example of an object to be plated, 16 denotes a plate, 18 denotes a plating solution supply container, and 22 denotes a plating solution supply container 18. Provided baffle plate, 24 is its through hole, 26 is a plating solution tank,
Reference numeral 28 denotes pumps, which are basically configured in the same manner as the conventional partial plating apparatus. A nozzle plate 36 is a metal plate mounted on the front surface of the plating solution supply container 18, and is preferably formed of a stainless steel plate. The nozzle plate 36 also serves as an anode. As shown in FIG. 2, the lead plate 14 is provided on the nozzle plate 36.
A plurality of ejection holes 38 of the same shape are opened corresponding to the plating areas of each unit lead frame. The nozzle plate 36 shown in FIG. 2 is for a quad-type lead frame. The four ejection holes 38 at the center are mainly provided on the stage, and the 12 ejection holes 38 on the periphery are located at the tip of the inner lead surrounding the stage. It is arranged to correspond to.

Each ejection hole 38 is preferably formed in a through hole having the same shape so that the plating solution pumped into the plating solution supply container 18 is ejected at substantially the same flow rate. Is formed. Preferably, the edge of the ejection hole 38 on the mask 12 side is chamfered as necessary as shown in FIG. 3, and the ejection angle of the plating solution is preferably adjusted by the taper angle of the chamfered portion 38a. is there.
Reference numeral 40 denotes an auxiliary electrode, which is screwed into a screw hole provided in the nozzle plate 36 and is provided at an arbitrary position, and protrudes toward the inner lead 14 as shown in FIG. For example, by protruding the auxiliary electrode corresponding to a corner portion or the like of a plating region where the plating solution is difficult to rotate, the current density of the portion can be increased and the plating area can be improved. Reference numeral 42 denotes a mounting hole for the nozzle plate 36. The nozzle plate 36 is mounted in a liquid-tight manner at the tip of the plating solution supply container 18 by a bolt (not shown). FIG. 5 shows another embodiment. In the present embodiment, the ejection holes 3
8 are formed only for the unit lead frame, and are formed in the same shape of the elongated hole. As described above, the shape and arrangement of the ejection holes 38 are not particularly limited, and are appropriately selected according to the shape of the plating region of the lead frame 14.

With the above-described configuration, the plating solution in the tank 26 is pumped up by the pump 28 and pumped into the plating solution supply container 18, and the plating solution is surrounded by the mask 12 from the ejection hole 38. By jetting the plating to the plating area of the lead frame 14, partial plating can be applied to a predetermined portion of the lead frame 14. In this case, since the nozzle plate 36 itself, which is a metal plate, is used as the anode, a large current density can be obtained, and the plating time can be shortened. The ejection holes 38 can be freely arranged at any position of the nozzle plate 36 corresponding to the plating area, and even in a complicated plating area, the plating solution can be uniformly ejected, and a plating film having a uniform thickness can be obtained. . By making the ejection holes 38 have the same shape, the flow velocity of the plating solution to be ejected can be made the same, and thereby the plating thickness can be made uniform. In particular, by providing the auxiliary electrode 40, it is possible to cope with a more complicated shape of the plating region. Further, by forming the nozzle plate 36 from a stainless steel plate, it can be formed at low cost.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the embodiments, and it is noted that many modifications can be made without departing from the spirit of the invention. Of course.

[0011]

According to the partial plating apparatus of the present invention,
With the simple structure, the plating time can be shortened, the plating thickness can be made uniform even in a complicated plating area, and the configuration can be made inexpensively.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an example of a partial plating apparatus.

FIG. 2 is a front view showing an example of a nozzle plate.

FIG. 3 shows a sectional view of a nozzle hole.

FIG. 4 shows a side view of the nozzle plate.

FIG. 5 is a front view showing another embodiment of the nozzle plate.

FIG. 6 is a sectional view of a conventional partial plating apparatus.

FIG. 7 is a front view of a conventional nozzle plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sparger 12 Mask 14 Lead frame 16 This plate 18 Plating solution supply container 36 Nozzle plate 38 Jet hole

──────────────────────────────────────────────────続 き Continuing on the front page (72) Norio Wakabayashi, Inventor 711, Toshida, Kurita-sha, Nagano City, Nagano Prefecture Inside (72) Inventor Nobuyuki Kurashima, 711, Torida, Kurita-Sha, Nagano, Nagano Prefecture Shinko (56) References JP-A-63-137192 (JP, A) JP-A-61-177390 (JP, A) JP-A-55-21502 (JP, A) JP-A-58-144494 ( JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C25D 5/02 C25D 5/08 C25D 7/12 H01L 23/50

Claims (4)

(57) [Claims] 1. A partial plating apparatus for covering a lead frame which is an object to be plated with a mask, spraying a plating solution from a nozzle into an opening of the mask, and plating a plating region of the object to be plated corresponding to the opening. The nozzle is a plating area of the lead frame.
And injection holes are arranged to jet the plating solution corresponds to the stage and / or the inner leads, said Li at a predetermined position
And an auxiliary electrode protruding toward the load frame.
And a metal plate, the partial plating system, which comprises using the metal plate as an anode. 2. The partial plating apparatus according to claim 1, wherein said ejection holes are a plurality of through holes having the same shape. 3. The partial plating apparatus according to claim 1, wherein the metal plate is made of stainless steel. 4. A tape is provided at an edge of the ejection hole on the mask side.
Claims wherein a par-shaped chamfer is formed.
Item 4. The partial plating apparatus according to item 1, 2 or 3.