JPH06252313A - Semiconductor lead frame plating device - Google Patents

Abstract

PURPOSE:To provide the title semiconductor lead frame plating device capable of removing any residual smut on a lead frame surface caused by etching step for obviating defective plating such as defective bonding, etc. CONSTITUTION:Within the title semiconductor lead frame plating device equipped with a degreasing means 1, a washing means 2, an etching means 3, another washing means 4, a pre-dipping means 5, a solder plating means 6, the other washing means 7, an alkali neutralizing means 8, the other washing means-9 and a drying means 10, an ultrasonic cleaning means 11 for ultrasonic cleaning step is provided between the etching means 3 and the solder plating means 6. Next, after finishing the etching step by the etching means 3, the semiconductor lead frames are to be ultrasonic-cleaned by the ultrasonic cleaning means 11 to be solder plated later.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor lead frame plating apparatus for applying a solder plating treatment to an exterior portion of a semiconductor lead frame.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing the structure of a conventional semiconductor lead frame plating apparatus of this type. As shown in the figure, the semiconductor lead frame plating apparatus includes a degreasing treatment means 1, a water washing treatment means 2, an etching treatment means 3, a water washing treatment means 4,
Pre-dip processing means 5, solder plating processing means 6, water washing processing means 7, alkali neutralization processing means 8, water washing processing means 9
And a drying treatment means 10.

The degreasing processing means 1 is a processing means for removing the oil adhering to the surface of the lead frame during the machining of the semiconductor lead frame, etc. Usually, the lead frame is immersed in a liquid tank containing a degreasing liquid to degrease it. The water washing treatment means 2 is a water washing for removing the degreasing liquid attached by the degreasing treatment,
Usually, the degreased lead frame is immersed in a water tank containing pure water. The etching treatment means 3 is a means for performing an etching treatment, and is usually immersed in a liquid tank containing an etching solution of sulfuric acid + hydrogen peroxide system for a predetermined time.

The washing process means 4 is a process of washing the lead frame which has been subjected to the etching process by immersing the lead frame which has been subjected to the etching process in a water tank containing pure water. The pre-dip processing means 5 is a process immediately before the solder plating process, and is usually performed by immersing it in a liquid tank containing the same acidic liquid as the plating liquid. In this pre-dip process, the etching treatment is followed by washing with water to remove the etching treatment liquid, but the etching treatment liquid is not completely removed even by this washing, and a very small amount of etching liquid adheres to the surface, leading to the lead frame surface. Since an oxide film is formed on the surface, the oxide film is removed and other impurities adhering to the surface are removed, and the same solution as the plating solution is used as the pre-dip solution, thereby maintaining the concentration of the plating solution at a predetermined value. To do so. The solder plating means 6 is a means for performing a solder plating treatment on the exterior portion of the lead frame, which is performed by energizing the solder material in the plating solution with the solder material as the anode and the lead frame as the cathode. The water washing treatment means 7 is a water washing for removing the plating treatment liquid adhered by the solder plating treatment, which is usually performed by immersing the lead frame after the plating treatment in a water tank containing pure water.

The alkaline neutralization processing means 8 is a means for neutralizing the residual plating solution. Usually, the lead frame that has been washed by the water washing processing means 7 is immersed in a liquid tank containing the neutralization solution. The water-washing means 9 is the last water-washing means, and is normally immersed in a water tank containing pure water. The drying processing means 10 is for performing drying after washing with water.

[0006]

With the recent miniaturization of semiconductor elements, the lead frame has become thinner year by year, and the pitch thereof has become narrower. In a copper (Cu) -based semiconductor lead frame, nickel (Ni) or silicon (Si) is dealt with in response to such a tendency toward thinning and narrow pitch.
In many cases, the strength of the lead frame material was increased by mixing the elements.

The above nickel (Ni) and silicon (Si)
When performing the solder plating treatment on the exterior portion of the copper (Cu) -based semiconductor lead frame mixed with the elements, the etching treatment means 3 performs the etching treatment before performing the solder plating treatment by the solder plating treatment means 6 as described above. I am doing it. In this etching processing means 3, an etching solution of sulfuric acid + hydrogen peroxide system is often used, but after Ni or Si contained in the lead frame material is dissolved by this etching processing, it is not separated from the surface of the lead frame. It often remains as so-called smut in the form of black powder. If the solder plating process is performed by the solder plating process means 6 with the smut remaining on the surface of the lead frame, there is a problem that plating defects such as poor adhesion occur.

The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor lead frame plating apparatus in which this smut is removed from the surface of the lead frame and plating defects such as poor adhesion do not occur. And

[0009]

In order to solve the above problems, the present invention comprises at least an etching treatment means for performing an etching treatment and a solder plating treatment means for subjecting a plating treatment to an etching treatment means on an exterior portion of a semiconductor lead frame. In a semiconductor lead frame plating apparatus that performs a solder plating process after performing an etching process with, an ultrasonic cleaning unit that performs ultrasonic cleaning is provided between the etching process unit and the solder plating process unit, and the etching process is performed by the etching process unit. After performing the above, ultrasonic cleaning is performed by the cleaning means, and then solder plating treatment is performed.

Further, the ultrasonic cleaning means is a water washing tank in which an ultrasonic vibrator is installed.

Further, the invention is characterized in that a rinsing tank for rinsing with water is installed next to the etching means, and then a rinsing tank with an ultrasonic transducer is installed.

Further, the semiconductor lead frame plating apparatus is provided with a pre-dip processing tank for performing a pre-dip processing just before the solder plating processing before the solder plating processing means, and an ultrasonic transducer is installed in the pre-dip processing tank. It is characterized by having done.

An ultrasonic transducer is installed in the processing tank of the etching processing means.

[0014]

By providing the ultrasonic cleaning means for performing ultrasonic cleaning between the etching processing means and the solder plating processing means, the smut adhered to the surface of the lead frame caused by the etching processing is completely removed, and the solder plating Defects such as defects will not occur.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a semiconductor lead frame plating apparatus of the present invention. In FIG. 1, the same reference numerals as those in FIG. 4 indicate the same or corresponding portions. As shown in FIG. 1, this semiconductor lead frame plating apparatus includes a degreasing treatment means 1, a water washing treatment means 2, an etching treatment means 3, a water washing treatment means 4, a pre-dip treatment means 5, a solder plating treatment means 6, and a water washing treatment means. 7, an alkali neutralization treatment means 8, a water washing treatment means 9 and a drying treatment means 10 are provided, and the ultrasonic washing means 1 is provided between the etching treatment means 3 and the water washing treatment means 4.
1 is provided.

In the plating apparatus having the above structure, the ultrasonic cleaning means 11 has an ultrasonic vibrator installed in a water tank. The semiconductor lead frame machined by sheet metal or the like is subjected to etching processing by the etching processing means 3 after each processing of the degreasing processing means 1 and the water washing processing means 2.
This point is the same as the conventional example. Etching process is sulfuric acid +
It is performed by immersing it in a hydrogen peroxide-based etching solution for a predetermined time. As described above, in the copper (Cu) -based semiconductor lead frame, nickel (Ni) and silicon (Si) elements are mixed in order to increase the strength. Therefore, when the etching process is performed, the Ni and Si elements are often dissolved and remain as black powdery smut on the surface of the lead frame. The lead frame on which the smut remains is immersed in the water tank of the ultrasonic cleaning means 11 containing pure water, and ultrasonic waves are emitted from the ultrasonic vibrator, so that the smut remaining on the surface of the lead frame. Are completely removed.

The lead frame from which the smut has been removed is washed with water by means of washing treatment means 4, pre-dip treatment by pre-dip treatment means 5, and solder-plated by solder-plating treatment means 6. Since the solder plating is subjected to ultrasonic cleaning as described above, the residual smut generated by the etching process is removed, and therefore plating with good adhesion is obtained. The solder-plated lead frame is then washed with water 7
After that, it is washed with water, washed with alkali neutralization treatment means 8 with alkali neutralization treatment means 8 and washed with water with water treatment treatment means 9, and finally dried with drying treatment means 10 to finish.

FIG. 2 is a diagram showing another structure of the semiconductor lead frame plating apparatus of the present invention. As shown in the figure, this plating apparatus is different in that the water washing treatment tank 4 is arranged immediately after the etching treatment means 3 and the ultrasonic washing means 11 is arranged, but the other points are the same as in FIG. . Even with this configuration, the smut remaining on the surface of the lead frame due to the etching process is completely removed by the ultrasonic cleaning of the ultrasonic cleaning means 11, and solder plating with good adhesion is performed.

FIG. 3 is a diagram showing another structure of the semiconductor lead frame plating apparatus of the present invention. As shown in the figure, in this plating apparatus, the ultrasonic transducer 12 is arranged in the liquid tank of the pre-dip processing means 5 '. Predip processing means 5 '
The same liquid as the solder plating liquid (acidic liquid) is stored in the liquid bath of No. 3, and the lead frame which is etched by the etching treatment means 3 and washed by the water washing treatment means 4 is immersed in the liquid bath, and the ultrasonic transducer is applied. By emitting ultrasonic waves from 12, the original pre-dip processing, that is, the removal of the oxide film formed on the surface of the lead frame and the impurities attached to the surface by the residual etching solution and the removal of the residual smut by the etching processing are performed at the same time. It can be implemented effectively. Therefore,
Solder plating by the solder plating processing means 6 also has good adhesion.

In the above embodiment, the ultrasonic cleaning treatment means 11 is arranged next to the etching treatment means 3 (see FIG. 1), or the washing treatment means 4 following the etching treatment means 3 is used.
Next, ultrasonic cleaning means 11 is arranged (see FIG. 2),
Alternatively, the ultrasonic transducer 12 is provided in the pre-dip processing means 5 '(see FIG. 3), but the present invention is not limited to this, and for example, the ultrasonic transducer is arranged in the processing tank of the etching processing means. However, ultrasonic cleaning may be performed at the same time as the etching process, or ultrasonic cleaning may be performed in the processing tank after the etching process is completed.

As described above, ultrasonic cleaning is performed in the treatment tank at the same time as the etching treatment or after the etching treatment is completed, so that smut or the like adhered to the surface of the lead frame may be removed depending on the type of alloy constituting the lead frame. In some cases, it can be effectively removed.

[0022]

As described above, according to the present invention, the ultrasonic cleaning means for ultrasonic cleaning is provided between the etching processing means and the solder plating processing means, and the smut adhered to the surface of the lead frame by the etching processing is provided. Is completely removed by ultrasonic cleaning, and then solder plating is performed.
It is possible to obtain an excellent effect that defects such as poor adhesion do not occur in the solder plating.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a semiconductor lead frame plating apparatus of the present invention.

FIG. 2 is a diagram showing another configuration of the semiconductor lead frame plating apparatus of the present invention.

FIG. 3 is a diagram showing another configuration of the semiconductor lead frame plating apparatus of the present invention.

FIG. 4 is a diagram showing another configuration of a conventional semiconductor lead frame plating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Degreasing treatment means 2 Water washing treatment means 3 Etching treatment means 4 Water washing treatment means 5 Predip treatment means 5'Predip treatment means 6 Solder plating treatment means 7 Water washing treatment means 8 Alkaline neutralization treatment means 9 Water washing treatment means 10 Drying treatment means 11 ultrasonic cleaning means 12 ultrasonic transducer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C23C 2/34

Claims (5)

[Claims] 1. An etching treatment means for performing at least an etching treatment and a solder plating treatment means for performing a plating treatment are provided, and after an etching treatment is applied to the exterior portion of the semiconductor lead frame by the etching treatment means, a solder plating treatment is applied. In a semiconductor lead frame plating apparatus, ultrasonic cleaning means for performing ultrasonic cleaning is provided between the etching processing means and the solder plating processing means, and the cleaning is performed during or after the etching processing by the etching processing means. A semiconductor lead frame plating apparatus, characterized in that ultrasonic cleaning is performed by means, and then solder plating treatment is performed. 2. The semiconductor lead frame plating apparatus according to claim 1, wherein the ultrasonic cleaning means is a water washing tank in which an ultrasonic vibrator is installed. 3. The semiconductor device according to claim 1, further comprising a washing tank for washing water next to the etching means, and then a washing tank having the ultrasonic transducer. Lead frame plating equipment. 4. The semiconductor lead frame plating apparatus comprises a pre-dip processing tank for performing a pre-dip processing immediately before the solder plating processing before the solder plating processing means, and an ultrasonic transducer is provided in the pre-dip processing tank. The semiconductor lead frame plating apparatus according to claim 1, which is installed. 5. The semiconductor lead frame plating apparatus according to claim 1, wherein an ultrasonic vibrator is installed in the processing tank of the etching processing means.