JPH05343444A - Bonding apparatus - Google Patents

Abstract

PURPOSE:To improve yield and throughput in an assembling step and to provide assembling technique for manufacturing a semiconductor device having high reliability by preventing deformation of a wire or lead due to a feeding deviation of a lead frame in the technique for assembling the device by using a heat block or a heating top having a recess or a protrusion. CONSTITUTION:A bonding apparatus comprises a mechanism for correcting a feeding deviation of a lead frame 1 transferred to a bonding area by a frame feeder 4 by horizontally moving a contact member 14 to be engaged with the frame 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of manufacturing semiconductor products, and is particularly effective when applied to an assembly process including a pellet bonding process or a wire bonding process.

[0002]

2. Description of the Related Art Among semiconductor device manufacturing processes, an assembling process includes a pellet bonding process for adhering a semiconductor pellet formed by dicing to a tab of a lead frame, a metal thin wire for an electrode of the semiconductor pellet and an external lead. For example, a wire bonding step of electrically connecting with a gold wire.

In the wire bonding process, the thin metal wire that electrically connects the electrode of the semiconductor pellet and the inner lead, which is the resin-sealed portion of the outer lead, is deformed by its own weight or an impact from the outside. There have been problems that have arisen. In order to prevent this, a method of performing wire bonding by providing a wire guide protrusion so as to be located between the tab and the inner lead at the time of wire bonding on the heat block that contacts and heats the lead frame has been conventionally used. I am using. This wire guide protrusion is described in JP-A-50-128465.

Further, in recent years, the lead frame has been made more multi-pin and thinner as the functions of semiconductor devices have been developed and miniaturized. Moreover, a new type of lead frame, for example, no tab as LOC (L ead O n C hip ), the semiconductor device of the type of bonding the lead frame through an insulator on the semiconductor pellet is also commercialized It's starting. As described above, with the diversification of the lead frame, the contact member of the lead frame used in the wire bonding process also has a special shape. For example, as the package of a semiconductor device is made thinner, as shown in FIG. Tab 24 to balance thickness
A lead frame whose surface is lower than the inner lead 26 surface (hereinafter referred to as a tab-lowering lead) is used.
In the wire bonding process using the tab lowering lead, a heat block or a partial contact member, a so-called heat piece, which is a contact member having a wire guide protrusion and a concave portion with which the tab abuts, is used. .. This heat piece is
It is set and fixed in advance in the bonding area of the heat block and can be replaced depending on the type of lead frame. 6 to 7 show the operation of setting the tab lowering lead on the heating piece. The tab lowering lead 27 is set on the heat block 29 in the bonding area in advance, and the heat feeder 30 is fixed on the frame feeder 3 in advance.
2 (FIG. 6). Next, heat block 2
9, the heating piece 30 and the tab lowering lead 27 come into contact with each other. At this time, the tab 24 is fitted to the tab contact portion 28 of the heating piece 30, and the wire guide protrusion 33 for preventing the deformation of the wire to be bonded is inserted between the tab 24 and the inner lead 26. . The inner lead 26 of the set tab lowering lead 27 is pressed by the lead pressing member 31, and wire bonding is performed to electrically connect the electrode of the pellet 25 and the inner lead 26 with a fine metal wire. (FIG. 7) Regarding the heat block mechanism, for example, JP-A-63-104436.
It is described in Japanese Patent Publication No. Further, a lead frame in which the tab is lower than the inner lead is disclosed in, for example, JP-A-51-29087 and JP-A-54-60563.

[0005]

Conventionally, the frame feeder corresponds to one frame feeder for one type of lead frame, and the position correcting pin corresponding to the type is installed. Recently, however, the flexibility has been advanced, and various types of lead frames can be handled per frame feeder. Furthermore, the shortening of the setup time was called for, the position correction pin was deleted, and instead, the transferred lead frame was detected using the technology to detect the position shift amount,
The mainstream method is to perform the bonding by correcting only the bonding point by feeding back the detection result to the bonding head of the wire bonding apparatus.

However, since the heat block or the heat piece having the concave portion or the convex portion used in the wire bonding such as the lead frame or the tab lowering lead using the above-mentioned wire guide protrusion is movable only up and down, the lead frame is misaligned. When the wire bonding occurs, the wire is deformed as shown in FIG. 8 even if the wire bonding is performed by correcting only the bonding point. Further, when the feed deviation amount is large, the tabs and the inner leads are mounted on the steps of the concave portions or the convex portions as shown in FIG. 9, and lead deformation occurs when the lead pressing member is pressed as it is.
It was confirmed by the present inventor that it would be defective.

Therefore, according to the present invention, in a semiconductor device assembling technique using a heat block or a heating piece having a concave portion or a convex portion, wire deformation or lead deformation due to feed deviation of a lead frame is prevented, and an assembling process is performed. It is an object of the present invention to provide an assembling technique capable of improving the yield in manufacturing and manufacturing a highly reliable semiconductor device.

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 outline of a typical invention among the inventions disclosed in the present application will be briefly described as follows. That is, the bonding apparatus is provided with a mechanism for correcting the feed deviation of the lead frame transferred by the frame feeder by horizontally moving the contact member fitted to the lead frame.

[0010]

According to the above-mentioned means, the lead frame is set at the prescribed position of the contact member by correcting the feed deviation of the lead frame. It is possible to prevent the leads from climbing up, and to assemble the semiconductor device without causing wire deformation or lead deformation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a main part of a wire bonding apparatus using the present invention. Reference numeral 4 is a frame feeder for transferring the lead frame 1. The frame feeder 4 includes a chute 5 on which the lead frame 1 is placed and a feed claw 6 for driving the chute 5. Reference numeral 7 denotes a bonding head portion, which is a capillary 9 for wire-bonding a bonding pad (not shown) of the semiconductor pellet 8 and the inner lead 2 of the lead frame 1, and the lead frame 1 is mechanically moved by the frame feeder 4 in the bonding area. After the position is set, a recognition means 10 is provided for performing image recognition and detecting bonding coordinates. Reference numeral 11 is a heat block for heating the lead frame 1 in order to thermocompress the wire 12. A heat piece 13 is provided on the lead frame contact surface of the heat block 11. The heat piece 13 is
Recessed tab contact portion 1 where the tab of the tab lowering lead should be located
4 and a wire guide protrusion 15 having a convex shape for preventing wire deformation. Below the heat block 11, a heat block drive mechanism 16 is provided, and after the lead frame 1 is transferred to the bonding position, the heat block 11 is raised and brought into contact with the lead frame 1. In this embodiment, the heat block 11
The heat block drive mechanism 16 is provided with a horizontal movement mechanism 17 so as to be horizontally movable. By providing the horizontal movement mechanism 17, when the lead frame 1 is misaligned, the convex wire guide protrusion 15 is provided between the inner lead 2 and the tab 3 before the heat block 11 is raised. The tab 3 has a concave tab contact portion 1
4 can be corrected so that they are respectively located.
A servo motor is used as the drive source of the heat block drive mechanism 16, for example.

Next, the operation of the wire bonding apparatus of this embodiment will be described with reference to FIGS.

FIG. 2 shows an operation sequence of the wire bonding apparatus of this embodiment. The lead frame 1 is mechanically transferred from the end of the frame feeder 4 to the bonding position by the feed claw 6. The recognizing means 10 recognizes the patterns of the lead frame 1 and the semiconductor pellet 8, compares the recognized image with the reference coordinates of bonding stored in advance in the storage means 20 by the comparing means 19, and converts the positional deviation amount into a pulse. The converted signal is converted and an operation signal is issued to the heat block drive mechanism 16. Based on the operation signal, the heat block 11 horizontally moves from the reference position, and the tab of the heating piece 13 set in the heat block 11 is brought into contact with the tab of the lead frame 1 and the tab periphery of the recognized tab. The part 14 and the wire guide protrusion 15 are located (FIG. 3). After that, the heat block 11 rises, and the wire guide protrusion 15 is fitted between the inner lead 2 and the tab 3, and the tab contact portion 14 is fitted to the portion of the tab 3, so that the heat piece 13 and the heat piece 13 are fitted together. The lead frame 1 contacts. The inner lead 2 of the lead frame 1 is pressed by the lead pressing member 18. The lead pressing member 18 also moves horizontally following the heat block 11. At the same time, the positional deviation amount pulse is also sent to the bonding head section 7 to start wire bonding between the bonding pad of the semiconductor pellet 8 adhered to the tab 2 of the lead frame 1 and the inner lead 2 (FIG. 4). In this way, the heat block side is moved without moving the lead frame to correct the lead frame feed misalignment, so that the recognition can be performed simultaneously with the recognition of the bonding point.

According to this embodiment, the following effects can be obtained. That is, (1) even if the lead frame is misaligned during wire bonding, the heat block moves in the horizontal direction, so that the position can be corrected in the horizontal direction, and the heat block rises to separate the heat piece from the lead frame. When abutting, the lead frame and the recess or protrusion of the heating piece can be fitted accurately. Therefore, it is possible to prevent wire deformation and lead deformation due to the displacement of the heating pieces.

(2) By feeding back the lead frame feed deviation information detected by the recognition means not only to the bonding head side but also to the heat block side, the bonding coordinates can be detected and the position of the heating piece can be recognized with one recognition. Correction and correction can be performed at the same time.

(3) Since the positional accuracy of the lead frame, the bonding head, and the heating piece is secured, the heating piece can be designed without considering the dimensional margin regarding the feed accuracy of the lead frame.

The invention made by the inventor of the present invention has been specifically described based on the embodiments. However, 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 positional deviation is corrected by horizontally moving the heat block, but the same effect can be obtained by fixing the heat block and horizontally moving only the heat piece. Further, the position may be corrected by driving the frame feeder after transferring the lead frame. In that case, the bonding head and heat block are fixed at the reference position, and the lead frame is moved to the reference position by feeding back a signal based on the information on the positional deviation between the reference position and the recognition position to the drive unit of the frame feeder. Let me correct it.

The lead frame used in the embodiment is
Although the description has been given on the case where the tab lowering process is performed, even in the lead frame which is not subjected to the tab lowering process, as long as the wire bonding is performed using the wire guide protrusion, the effect of the present invention is sufficiently exerted. It is a thing. In the LOC type semiconductor device which is being used in recent years, since the pellet directly contacts the heating piece, when the present invention is used in the wire bonding step, chipping of the pellet can be prevented.

In the embodiments, the present invention has been described by using the wire bonding apparatus as an example. However, the same effect can be obtained by using the present invention in a pellet bonding apparatus.

[0021]

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

That is, in the bonding apparatus, the feed deviation of the lead frame transferred by the frame feeder is corrected by horizontally moving the abutting member that abuts the lead frame, so that the wire guide protrusion of the abutting member is corrected. Since the tab contact portion of the contact member or the inner lead of the lead frame or the tab contact portion of the contact member can be accurately fitted to the lead frame, it is possible to prevent wire deformation and lead deformation due to positional displacement. The yield and throughput in the bonding process can be improved.

[0023]

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a wire bonding apparatus that is an embodiment of the present invention.

FIG. 2 is a diagram showing an operation sequence of the wire bonding apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram showing an operation of a heat block of the wire bonding apparatus which is an embodiment of the present invention.

FIG. 4 is a diagram showing a state in which a lead frame in contact with a heating piece is wire-bonded.

FIG. 5 is a cross-sectional view of a semiconductor device using tab-down leads.

FIG. 6 is an explanatory diagram of the operation of a conventional heat block.

FIG. 7 is an explanatory diagram of an operation of a conventional heat block.

FIG. 8 is a diagram showing wire deformation that occurs in a conventional wire bonding apparatus.

FIG. 9 is a diagram showing lead deformation that occurs in a conventional wire bonding apparatus.

[Explanation of symbols]

1 ... Lead frame, 2 ... Inner lead, 3 ...
Tab, 4 ・ ・ Frame feeder, 5 ・ ・ Shoot, 6 ・
・ Feeding claws, 7 ・ ・ Bonding head part, 8 ・ ・ Semiconductor pellets, 9 ・ ・ Capillary
..Heat blocks, 12 ... Wires, 13 ... Heating pieces, 14 ... Tab contact portions, 15 ... Wire guide projections,
16 ··· Heat block drive mechanism, 17 · · Horizontal movement mechanism, 18 · · Lead holding member, 19 · · Comparison means, 2
0 ... Storage means, 21 ... Wire, 22 ... Semiconductor device, 23, 23a, 23b ... Encapsulating resin 24 ... Tab, 25 ... Semiconductor pellet, 26 ... Inner lead, 27 ... Lead frame, 28 ... Tab contact part, 29 ... Heat block, 30 ... Heat piece, 3
1 ... Lead pressing member, 32 ... Frame feeder,
33 .. Wire guide protrusions

Claims (4)

[Claims] 1. A contact member having a concave portion or a convex portion to be fitted with a lead frame, a pressing member for pressing an inner lead portion of the lead frame against the contact member, and the lead frame transferred to a bonding area. And a bonding head having a bonding head for bonding an object to be bonded to the lead frame, wherein the contact member is horizontally moved to a position where the concave portion or the convex portion fits with the shape of the lead frame. After that, the bonding apparatus rises and comes into contact with the lead frame. 2. The bonding apparatus according to claim 1, wherein the contact member has a driving means for moving in the horizontal direction. 3. The bonding apparatus has a storage means for storing a reference position at which an object to be bonded is bonded and a recognition means for recognizing a bonding position of the transferred lead frame, and is displaced from the reference position. The displacement amount of the recognized position is detected, and the contact member moves based on the detection result.
Alternatively, the bonding apparatus according to claim 2. 4. A contact member for a lead frame having a concave portion or a convex portion to be fitted with the lead frame, a storage means for storing a reference position of the lead frame, and a recognition for recognizing a bonding position of the lead frame. A bonding apparatus comprising: a bonding head for bonding an object to be bonded to the lead frame; and a correction means for correcting the positional deviation amount between the reference position and the bonding position to the bonding head. The bonding apparatus is provided with a contact member driving means for moving the contact member horizontally, and the corresponding contact member driving means is driven by the correction of the positional deviation amount by the correction means.