JPH07153888A - Semiconductor manufacturing apparatus and manufacture of semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To obtain a uniform thickness of plating during execution of the electric plating process to prevent poor conductivity due to adhesion of plated layer. CONSTITUTION:A semiconductor device manufacturing apparatus is composed of a frame holding device 2 providing a first conductor member (cathode) 8 which is in contact with every outer leads 1a and soaking a single lead frame 1 in which a semiconductor chip is sealed by the molding into the plating solution by holding it, a second conductor member (anode) 9 soaked into the plating solution 4 and a DC power source 7 for impressing a voltage to the first and second conductor members 8, 9. Thereby, distance between the lead frame 1 to be plated and the second conductor member 9 is always kept constant under the approximated condition to realize a uniform plating thickness. Moreover, since the electric plating is performed under the condition that the lead frame 1 is isolated into a single lead frame 1, poor conductivity of the outer lead 1a due to adhesion of plated layer can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus and a method for manufacturing a semiconductor integrated circuit device, and more particularly to an electroplating technique for a lead frame in which a semiconductor chip is molded and sealed.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit device, a semiconductor chip is molded and sealed in a strip-shaped lead frame, and an outer lead is formed by separating and cutting into a single lead frame by a die, and finally forming a finished product. I am trying. The strip-shaped lead frame used here is electroplated collectively in units of several frames.

In the first place, the plating thickness of the lead frame is required to be uniform and not less than a certain thickness so that predetermined characteristics can be exhibited. Japanese Patent Laid-Open No. 3-85 discloses a technique relating to such lead frame plating.
As disclosed in Japanese Patent Laid-Open No. 750, there is disclosed a technique in which a thick film solder plating is performed in advance so that a solder supplying step at the time of mounting on a substrate is omitted.

[0004]

However, as described above, according to the conventional technique of electroplating strip-shaped lead frames collectively in units of several frames, the metal deposited on the frame far from the anode is deposited. Since the number of atoms is reduced, there is a problem that the metal film is not sufficiently formed and the plating thickness becomes thin, and the plating thickness varies from frame to frame.

Further, according to the conventional technique of cutting and molding a plurality of lead frames into a single lead frame after electroplating, plating scraps are generated and attached to the outer leads, or already formed on the molding die. There was a problem that the plating scraps that had adhered to the outer leads would reattach to the outer leads, resulting in a short circuit between the outer leads and poor electrical continuity.

Therefore, an object of the present invention is to provide a technique capable of making the plating thickness of a lead frame uniform during electroplating.

Another object of the present invention is to provide a technique capable of preventing the conduction failure of the outer leads due to the deposition of plating scraps.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0009]

The typical ones of the inventions disclosed in the present application will be outlined below.

That is, the semiconductor manufacturing apparatus of the present invention is an apparatus for electroplating a lead frame, which is provided with a cathode that comes into contact with all outer leads and holds a single lead frame in which a semiconductor chip is molded and sealed. Then, a frame holder that is immersed in the plating solution, an anode that is immersed in the plating solution and that deposits metal atoms that form a metal coating on the lead frame together with the cathode, and a DC that applies voltage to the cathode and the anode. It consists of a power supply.

Further, in the method for manufacturing a semiconductor integrated circuit device of the present invention, a series of lead frames in which semiconductor chips are molded and sealed are separated into a single lead frame and then immersed in a plating bath for electroplating. Is.

[0012]

According to the semiconductor manufacturing apparatus and the manufacturing method having the above-described configuration, since electroplating is performed for each single lead frame, the distance between the lead frame to be plated and the anode is always close. Is kept constant.
Therefore, the metal coating is uniformly and sufficiently formed on any of the lead frames, and the plating thickness can be made uniform.

Further, since electroplating is performed with the lead frame separated into a single lead frame, plating scraps may be generated and adhered, or plating scraps already adhered may be re-adhered to the outer leads. Therefore, it is possible to prevent the conduction failure of the outer leads due to the adhesion of plating scraps.

[0014]

Embodiments of the present invention will now be described in more detail with reference to the drawings.

(Embodiment 1) FIG. 1 is an explanatory view showing a semiconductor manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II of the semiconductor manufacturing apparatus.

In the semiconductor manufacturing apparatus of this embodiment, the lead frame 1 is electroplated, whereby the soldering mountability when it is mounted on a printed circuit board (not shown) is secured, and corrosion due to oxidation is prevented. To do.
Here, in the lead frame 1 held by the frame holder 2, a series of lead frames 1 in which semiconductor chips (not shown) are molded and sealed are cut by a cutting die to form outer leads 1a, Single leadframe 1
It is said that.

As shown in FIG. 1, such a single lead frame 1 is added to a plating solution 4 filled in a plating bath 3.
The frame holder 2 for holding and immersing is formed of a non-conductive material such as fluororesin. An upper portion of the frame holder 2 is fixed to an arm 5, and the arm 5 is rotatably attached to a transfer member that transfers the lead frame 1 on which a semiconductor chip is molded from a predetermined place to a plating tank, and a plating treatment is performed. The flow of the lead frame 1 in the process is made smooth.

As shown in FIG. 2, the frame holder 2 is formed by a pair of frames of a front portion 2a and a rear portion 2b, and the opposing surfaces of both are made of, for example, stainless steel, and are connected to the DC power supply 7. A negatively charged first conductive member (cathode) 8 is provided so as to project. The lead frame 1 described above is used for all outer leads 1
While a is in contact with the first conductive member 8, the front end of the frame holder 2 is clamped by the front portion 2a and the rear portion 2b.

A DC power source 7 is provided near the frame holder 2.
Second conductive member (anode) 9 connected to the positively charged
Is immersed in the plating solution 4, and a metal coating is formed on the lead frame 1 by the first and second conductive members 8 and 9.

A pump 10 is provided outside the plating tank 3, and the plating solution 4 filled in the plating tank 3 is circulated in the tank by the pump 10 to make the concentration uniform. .

According to the semiconductor manufacturing apparatus of this embodiment, the single lead frame 1 in which the semiconductor chip is molded and sealed is electroplated, so that the lead frame 1 and the second lead frame 1 to be plated are plated. The distance from the conductive member 9 is
It will always be kept constant in a close state.
Therefore, since the metal coating is uniformly and sufficiently formed on any of the lead frames 1, the plating thickness can be made uniform.

Similarly, since the semiconductor chip is mold-sealed and electroplating is performed in a state where it is separated into a single lead frame 1, it is not necessary to cut the lead frame 1 after plating. Therefore, plating scraps are not generated during cutting and adhere to the outer leads 1a, and plating scraps that have already adhered to the mold are not redeposited on the outer leads 1a. It is possible to prevent defects in advance.

(Embodiment 2) FIG. 3 is an explanatory view showing a semiconductor manufacturing apparatus according to another embodiment of the present invention.

The semiconductor manufacturing apparatus of this embodiment is substantially the same as that of the first embodiment, but is different from the first embodiment in that the outer lead 11a of the lead frame 11 to be electroplated is not molded. . In the drawings of this embodiment, the same parts as those of the first embodiment are designated by the same reference numerals.

As in the present embodiment, it is also possible to electroplat the lead frame 1 into a single lead frame 1 in a cut state and form the outer leads 11a after the plating is completed. As a result, the metal coating is uniformly and sufficiently formed on all the lead frames 11, and the plating thickness can be made uniform.

(Embodiment 3) FIG. 4 (a) is a front view showing a frame holder of a semiconductor manufacturing apparatus according to still another embodiment of the present invention, and FIG. 4 (b) is IV-IV of the frame holder. It is sectional drawing which follows the line.

As shown in FIG. 4, the frame holder 22 of this embodiment is different from the frame holders of the first and second embodiments in that it holds the shoulder portion of the outer lead 1a. In the drawings of this embodiment, the same parts as those in the first embodiment are designated by the same reference numerals.

Also in the semiconductor manufacturing apparatus using the frame holder 22 shown in this embodiment, the plating thickness can be made uniform as in the semiconductor manufacturing apparatus in the above-mentioned embodiment, and the outer leads 1a are electrically connected. It is possible to prevent defects.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the present embodiment, the lead frames 1 and 11 are immersed vertically in the plating solution, but they may be immersed horizontally or obliquely.

The outer leads 1a and 11a may be clamped by the frame holders 2 and 22 at positions other than the tips or shoulders as shown in the above-mentioned embodiment. The package of the circuit device can be various.

[0032]

The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.

(1) That is, according to the semiconductor manufacturing apparatus and the manufacturing method thereof of the present invention, electroplating is performed for each single lead frame, which is different from the case where electroplating is performed collectively in units of several frames. The distance between the lead frame to be plated and the anode is always kept constant in the close state. Therefore, since the metal coating is uniformly and sufficiently formed on any of the lead frames, the plating thickness can be made uniform.

(2) Also, since the electroplating is performed with the lead frame separated into a single lead frame,
There is no need to cut the lead frame after plating.
Therefore, plating scraps are not generated during cutting and adhere to the outer leads, and plating scraps that have already adhered to the cutting die do not re-adhere to the outer leads. It becomes possible to prevent it in advance.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a semiconductor manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the semiconductor manufacturing apparatus taken along line II-II.

FIG. 3 is an explanatory diagram showing a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

4A is a front view showing a frame holder of a semiconductor manufacturing apparatus according to a third embodiment of the present invention, and FIG. 4B is a sectional view taken along line IV-IV of the frame holder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 lead frame 1a outer lead 2 frame holder 2a front part 2b rear part 3 plating tank 4 plating solution 5 arm 6 transfer member 7 DC power supply 8 first conductive member (cathode) 9 second conductive member (anode) 10 pump 11 lead frame 11a outer lead 22 frame holder

Claims (2)

[Claims] 1. A semiconductor manufacturing apparatus for electroplating a lead frame, comprising a single lead frame having a cathode in contact with all outer leads and having a semiconductor chip molded and held. A frame holder that is immersed in a plating solution, an anode that is immersed in a plating solution and that deposits metal atoms that form a metal coating on the lead frame together with the cathode, and a direct current that applies a voltage to the cathode and the anode. A semiconductor manufacturing apparatus comprising a power supply. 2. A method of manufacturing a semiconductor integrated circuit device, wherein a series of lead frames each having a semiconductor chip molded and sealed are separated into a single lead frame and then immersed in a plating bath for electroplating.