JP2751550B2 - Semiconductor chip bonding equipment - Google Patents

Description

The present invention relates to a semiconductor chip bonding apparatus. More specifically, the present invention relates to a semiconductor chip bonding apparatus. The present invention relates to a means for correcting a lead frame feed position in order to accurately position a semiconductor chip at a mounting position according to the mounting position.

(Prior Art) A means for bonding a semiconductor chip to a lead frame is formed by providing a bond applying means and a mounting means on a lead frame transport path, and feeding the lead frame at a pitch while forming a pitch on the lead frame. A bond is applied to the bonded portion, and a semiconductor chip is mounted on the applied bond.

In performing such a bonding operation, the bonding portion must be accurately positioned at a bond application position by a bond application unit or a semiconductor chip mounting position by a mounting unit. For this reason, Japanese Unexamined Patent Publication
Japanese Patent Publication No. 188328 discloses a lead frame feeding means.

In this method, the position of the lead frame is set in the transport direction so that the bonding portion of the semiconductor chip at the head of the lead frame is positioned upstream of the coating position and at a pitch feed start position that is an integral multiple of the pitch with respect to the mounting position. The means for adjusting the pitch feed start position of the lead frame which can be adjusted is provided.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional means, since there are various errors such as a dimensional error of the lead frame, the lead frame is started to be pitch-fed by an integral multiple of the pitch as described above. Accurately locating to a position is extremely difficult in practice, and even if it were possible to do so,
Thereafter, various errors such as a pitch feed error occur, so that it is almost impossible to accurately position the bonding portion at the bond application position or the mounting position so as to satisfy the required positional accuracy.

Therefore, an object of the present invention is to provide means for solving the above-mentioned problems of the conventional means.

(Means for Solving the Problems) In order to achieve this, the present invention provides a semiconductor chip bonding apparatus in which a lead frame feed position correcting means is provided on a lead frame transport path by a pitch feed means. Means, a plurality of pins which are protruded at a pitch in the feed direction of the lead frame and are fitted into pin holes opened at a pitch on the lead frame,
A drive means for moving these pins up and down so as to fit these pins into these pin holes in synchronization with the pitch feed is provided, and the size of the pins on the downstream side is adjusted to the size of the pins on the upstream side. It is larger than the size.

(Operation) According to the above configuration, the pins are intermittently fitted into the pin holes in synchronization with the pitch feeding of the lead frame by the pitch feeding means, thereby correcting the displacement of the lead frame in the feeding direction. The bonding part is accurately positioned at the bond application position or the mounting position.

Example Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a bonding apparatus, in which 1 is a main body table, and a magazine 3 for stacking and storing lead frames 2 is provided at the front thereof. Further, on the upper portion of the table 1, a pitch feed means 4 for the lead frame 2, a bond applying means 5 such as a dispenser for applying a bond to the lead frame 2, and a mounting for mounting the semiconductor chip 7 on the applied bond. Means 6 are provided side by side. Numeral 8 denotes a transport unit which is located above the magazine 3 and sucks the lead frame 2 by the pad 9 and transports the lead frame 2 to the pitch feed unit 4.

The pitch feed means 4 includes an upper pawl 41 and a lower pawl 42,
The side edges of the lead frame 2 conveyed by the conveying means 8 are clamped from above and below, and are intermittently pitch-fed to the bond applying means 5 and the mounting means 6. A plurality of bonding portions (generally called islands) of the semiconductor chip 7 are formed at intervals on the lead frame 2, and the feed pitch of the pitch feeding means 4 is made to match the pitch of the bonding portions. In addition, the interval T between the bond applying unit 5 and the mounting unit 6 is set so that the bond application and the mounting of the semiconductor chip 7 can be performed in synchronization with the pitch feed.
Is configured to be an integral multiple of the pitch.
When the pitch of the bonding portion is changed due to a change in the type of the lead frame 2, the feed pitch of the pitch feed means 4 is adjusted, and the position of the bond applying means 5 is adjusted in the feed direction, so that the interval T is reduced. It can be adjusted.

FIG. 2 shows a means for correcting the feed position of the lead frame 2. Reference numeral 20 denotes a frame disposed on the transport path of the lead frame 2 in parallel with the upper pawl 41, and a plurality of pins 21 (21a to 21e) projecting from the lower surface thereof at a pitch. Also, pin holes 22 into which the pins 21 are fitted are formed at intervals on the side edges of the lead frame 2 (see also FIG. 3). K is the above-described bonding portion, and a bond is applied to the bonding portion K and the semiconductor chip 7 is mounted.

The diameter of each of the pins 21a to 21e gradually increases from the upstream side to the downstream side in the feed direction N of the lead frame 2, and the tip ends thereof are tapered so as to be easily fitted into the pin holes 22. Of the taper surface 23.

As shown in FIG. 4, the frame 20 is supported by a rod 24, and a roller 25 pivotally mounted on a lower end of the rod 24
It is in contact with the cam 26. 27 is a rod guide, 28 is a roller
A coil spring for resiliently pressing 25 to the cam 26,
24 to 28 constitute driving means for moving the pin 21 up and down. Therefore, when the cam 26 is rotated by a motor or the like,
The pin 21 moves up and down and fits into the pin hole 22. This fitting timing is opposite to the clamp timing of the lead frame 2 by the upper claws 41 and the lower claws 42. When the upper claws 41 and the lower claws 42 are opened to release the clamped state, the pin 21 descends. When the upper claws 41 and the lower claws 42 are fitted into the pin holes 22 and clamped, they are separated from the pin holes 22.

Here, as shown in FIG. 2 (a) and FIG. 3 (a), when the first pin 21a descends and fits into the pin hole 22, the position error in the X1 direction is , The tapered surface 23 of the pin 21a hits the inner edge of the pin hole 22,
The position error is corrected by moving the lead frame 2 slightly (△ t1) in the X2 direction. Also, as shown in FIG. 3 (b), the lead frame 2 is pitch-fed and
When the pin 21b fits into the 22, the position correction of Δt2 is similarly performed. 3 (c) and FIG. 2 (b) are enlarged views of the pin 21e having the maximum diameter inserted into the pin hole 22, and the position of the distance Δt5 is corrected.

As described above, according to this means, as the lead frame 2 is pitch-fed to the downstream side, the pins 21 whose pin diameters gradually increase are inserted into the pin holes 22 in order, so that the lead frame 2 is pitch-fed. Then, strict position correction in the feed direction is gradually performed, and the bonding portion K
Will be accurately positioned at the bond application position by the bond application means 5 and the mounting position by the mounting means 6.
As shown in FIGS. 2 (a) and 2 (b), if the pin 21 is not fitted deeply into the pin hole 22 but only the tapered portion at the tip is fitted, the pin 21 rises. Then pin hole
When the lead frame 2 comes off, large sliding friction occurs between the outer peripheral surface of the pin 21 and the inner edge portion of the pin hole 22, and it is possible to prevent the lead frame 2 from being displaced.

Further, as shown in FIG. 5, the shape of the pin 21 may be such that the distal end surface 24 is spherical, and the point is that the shape is such that the pin 21 can be smoothly fitted into the pin hole 22.

This apparatus has the above configuration, and the operation will be described next with reference to FIG.

In FIG. 6A, three lead frames 2a, 2b,
2c is on the transport path, and the upper pawl 41 and the lower pawl 42 are open and unclamped. In the figure, reference numeral 10 denotes an NC table for moving the conveying means 8 in the feed direction, and 11 denotes a sensor for detecting the rear end of the lead frame 2.

In this state, the conveying means 8 descends to adsorb the lead frame 2d laminated on the magazine 3, and the upper claws 41 and the lower claws 41
Reference numeral 42 is closed to clamp the lead frame 2 on the transport path (FIG. 9B). Next, the pitch feeding means 4 clamps or feeds the lead frame 2 pitch forward, and the feeding means 8 feeds the lead frame 2d forward,
The front end of the lead frame 2d is made to wait at the standby position a (FIG. 3C).

Then the transporting means 8 descends and moves forward slightly,
The lead frame 2d is sent to the clamp position by the upper claws 41 and the lower claws 42, and the upper claws 41 and the lower claws 42 are opened to return to the original position ((d) in the same figure). The upper pawl 41 and the lower pawl 42 clamp the leading end of the lead frame 2d (FIG. 9E), and feed the lead frame 2d forward by pitch.

Next, as shown in FIG. 4F, the transporting means 8 returns to the position above the magazine 3 to prepare for the transport of the next lead frame 2e, and the upper claws 41 and the lower claws 42
Is intermittently clamped, and is forwardly pitch-fed to apply a bond to the bonding portion K of the lead frame 2 which has arrived immediately below the bond applying means 5 by the bond applying means 5 and to bond directly under the mounting means 6. The semiconductor chip 7 is mounted on the bond of the part K.

By the way, as described in the above-mentioned JP-A-62-188328, the position of the bonding portion K at the head of the lead frame 2 at the standby position a in FIG. It is desirable that the position be an integral multiple of the pitch of the portion K. However, as mentioned above,
Due to various errors such as a dimensional error of the lead frame 2 and a stop error of the NC table 10, it is practically difficult to accurately wait at such an integral multiple of the position. Even if this could be done, there is also an error in the pitch feed of the pitch feed means 4, especially when the upper pawl 41 and the lower pawl 42
When clamping is performed and pitch feeding is performed, slippage is likely to occur, so that a feeding error occurs, and the bonding portion K is accurately positioned at the bond application position by the bond applying unit 5 and the mounting position of the semiconductor chip by the mounting unit 6. It is almost impossible.

Therefore, this means corrects the feed position of the lead frame 2 by moving the pin 21 up and down and intermittently fitting the pin 21 into the pin hole 22 in synchronization with the pitch feed by the upper and lower claws 41 and 42. Then, the bonding portion K can be accurately positioned and stopped at the bond application position or the mounting position.
Therefore, the standby position a does not need to be a position of an integral multiple as described above, and the transporting means 8 only needs to roughly feed the lead frame 2 to the pitch feeding means 4 side, and thereafter, the lead 21 is read by the pins 21. While gradually and strictly correcting the position of the frame 2, the bonding portion K can be accurately stopped at the bond application position or the mounting position.

(Effects of the Invention) As described above, according to the present invention, a lead frame feed position correcting means is provided on the lead frame transport path by the pitch feed means, and the feed position correcting means sets the pitch in the lead frame feed direction. A plurality of pins that are protruded in the lead frame and are inserted into the pin holes that are opened at a pitch in the lead frame, and these pins are inserted into these pin holes in synchronization with the pitch feed. And the driving means for moving the pins up and down, and the size of the pins on the downstream side is made larger than the size of the pins on the upstream side. The feed position of the frame is accurately corrected, and the bonding part of the lead frame can be accurately positioned at the bond application position or the semiconductor chip mounting position. Wear.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a front view of a bonding apparatus, FIG. 2 is a front view of a main part, and FIGS. 3 (a), (b) and (c) are feeding. 4 is a front view of the vertical movement means, FIG. 5 is a side view of another embodiment of the pin, and FIGS. 6 (a), (b), (c), (d) and (e). ),
(F) is a front view of a pitch feed order. 2 Lead frame 4 Pitch feeding means 5 Bond application means 6 Mounting means 7 Semiconductor chip 8 Transport means 21 Pin 22 Pin holes 24 to 28 Driving means

Claims (1)

(57) [Claims] 1. A bond applying means for applying a bond to a bonding portion of a lead frame, a mounting means for mounting a semiconductor chip on the applied bond, and an intermittent lead frame to the bond applying means and the mounting means. In a semiconductor chip bonding apparatus provided with a pitch feeding means for feeding a pitch to the semiconductor device and a feeding means for feeding the lead frame to the pitch feeding means,
A lead frame feed position correcting means is provided, and the feed position correcting means is provided with a plurality of pins which are protruded at a pitch in the lead frame feed direction and which are fitted into pin holes opened at a pitch in the lead frame. And a drive means for moving these pins up and down in order to fit these pins into these pin holes in synchronization with the pitch feed. The size of the pins on the downstream side is Characterized in that the size of the pins is larger than the size of the pins.