JPH038349A - Die-bonding method and device - Google Patents

Abstract

PURPOSE:To bond a chip at a proper angle to a land by recognizing the inclinations of a work and a chip, respectively, and performing the bonding after rotating a tool by the operation based on recognition results. CONSTITUTION:First, the image of the chip 3 to be sucked is picked up by a television camera 12, and the video signal is input into a recognizing device 14, which recognizes the inclination Qc of the chip. Next, a tool advances to right above the sucking position M of the chip, and the tool lowers and sucks the chip 3 by vacuum. Next, though the tool rises after sucking the chip 3 and then shifts, in the midst of its shift, it gives a motor control signals based Qc+Qw (inclination of a land 11) or Qc-Qw which is operated based on the recognition by the recognition devices 14 and 15. Thereupon, a motor driving shaft rotates based on the operation results, and a tool holder rotates. And when the tool reaches right above bonding point N, the ridgeline of the chip 3 becomes parallel with the ridgeline of the land 11, so the chip 3 is bonded correctly to the land 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention relates to a die bonding method and apparatus that can be particularly adapted to high-speed automation.

[Conventional technology]

Examples of conventional die bonding methods include those shown in FIGS. 7 and 8.

This is because a bonding tool such as a vacuum suction type collet 2 attached to the tip of the bonding arm 1 descends with the bonding arm l from directly above the semiconductor chip 3 (hereinafter referred to as chip 3) to be suctioned as shown by the two-dot chain line. After vacuum-chucking the chip 3, it rises to a predetermined height, then moves horizontally, stops when the collet 2 comes directly above the bonding point 10, and then descends together with the bonding arm 1 to place the chip 3 on a workpiece, such as a lead frame. Thermocompression bonding (bonding) onto W.

After the bonding is completed, the bonding arm 1 and the collet 2 rise to a predetermined height, move S again in the horizontal direction, and repeat the above operation.

In Figures 7 and 8, 4 is a bonding head, 5 is a wafer, and 6 is a wafer ring that holds the wafer. The wafer ring 6 is fixed on an XY child table (not shown), and by operating the XY table, semiconductor chips to be attracted are sequentially moved six times to the suction position. A chip push-up mechanism 7 is provided directly below the suction position, and when the chip 3 is attracted, a push-up pin 8 pushes up the chip 3 through the adhesive sheet directly below the chip 3, thereby facilitating vacuum suction. Note that 9 is a work guide.

(Problem to be Solved by the Invention) However, in the conventional die bonding method as described above, if the bonding location of the chip 3 and/or workpiece W, for example, the land portion, is tilted, the chip 3 is attracted by the collet 2 while being tilted, Since the chip 3 is transported to the bonding point tilted and bonded to the tilted bonding point, bonding cannot be performed in the correct direction due to the additive effect of the tilt of the chip 3 and the tilt of the workpiece W. There is a problem with recognition accuracy in the wire bonding process after the process, and i! A problem arose.

That is, as shown in FIG. 9, when both the chip 3 and the land 11 are in the correct orientation in (a), there is no need to correct the orientation of the chip 3 and the land 11, but (b) in the diagram and (8) As shown in the figure, when the chip 3 is tilted to the right or left by Qc and the land 11 is in the correct position, the chip 3 is tilted by Qc.
It becomes necessary to correct the rotation by c to the left or right.

Also, in the figure (:), the chip 3 is tilted to the right by Qc, while the land 11 is tilted to the right by an even larger Qw.
It becomes necessary to correct the rotation to the right by an angle of Q+y-Qc. (N) In the figure, chip 3 is Qc in the same way.
It becomes necessary to rotate the tip 3 to the left by an angle of -Qw.
It is necessary to correct the rotation of the chip 3 in the right direction by the angle of Qw.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and it recognizes the inclination angles of the workpiece and the chip, advances the tool directly above the tool suction position, and lowers the chip. adsorbs,
The present invention provides a die bonding method and apparatus in which bonding is performed after rotating the tool to align the tip with the inclination angle of the workpiece by calculation based on the recognition result while the tool is moved directly above the bonding point. Accordingly, the chip 3 can be placed at the correct position on the workpiece W, and bonding with high mounting accuracy is possible.

〔Example〕

An embodiment of the method and apparatus of the present invention will be described below with reference to the drawings. FIG. 1(a) is a plan view of a wafer 5 and a work W. The wafer 5 is formed by adhesively holding a large number of divided chips 3, and is expanded and held by a wafer ring 6. Due to the expansion of the wafer ring 6, each chip 3 is tilted by an angle Qc as shown in FIG.

After adsorbing the chip 3, the tool 2 attached to the tip of the bonding arm 1 (see Figure 3.4) moves in the direction of the arrow
1 and then along arrow x2 to bond the chip 3 onto the land 11 ((8) in FIG. 1).

The arrow Y indicates the direction of movement of the work W perpendicular to xl, and the work W moves one pitch p every time bonding is completed.
move in the direction of arrow Y.

As shown in FIG. 1 (8), the land 11 to which the chip 3 is to be bonded is placed at an angle Q, for example, with respect to the direction of the arrow Y.
It is tilted by w, and the tilt angle Qll+ is for each land 1
The actual situation differs depending on the situation. N indicates a bonding point.

Next, in Fig. 2, 12 is the chip suction position M (first
13 is the bonding point N (see Figure 1 (8)).
Television cameras 14 and 15 installed directly above the television cameras 14 and 15 receive video signals emitted from the television cameras 12 and 3, respectively, and recognize the inclination angles Qc and Q stomach, respectively.
is a monitor.

Next, the tool rotating means K attached to the bonding arm 1 will be explained with reference to FIG. 3 which is a plan view, FIG. 4 which is a side view, and FIG. 5 which is a front view.

1 is a bonding arm fixed to the bonding head 4, 17 is a bracket fixed to the tip of the bonding arm 1, 18 is a tool holder guide unit integrally attached to the bracket 17, and 19 is a tool 20 for chip adsorption and bonding. This is a tool holder that holds the holder, and the shaft center is provided with a vacuum suction hole (not shown). This tool holder 19 is fitted into a shaft hole provided in the tool holder guide portion 18 so as to be movable upward and downward.

The tool 20 may be a needle as shown in FIGS. 3 to 5, or a collet 41 as shown in FIG. 6.

Reference numeral 21 designates an overhanging portion that is integral with the tool holder guide portion 18. A driven pulley 22 is rotatably pivotally attached to the overhanging portion 21, and is provided on the upper surface of the driven pulley 22 eccentrically from the rotation axis of the pulley. An eccentric pin 23 is implanted.

At the upper part of the tool holder 19, a swinging rod 26 having an engagement groove 24 on one side and a boss portion 25 on the opposite side is attached to a set screw 27.
The engagement groove 24 engages with the eccentric pin 23, and a stopper rod 28 of a predetermined length is fixed to the boss portion.

Reference numeral 29 denotes a bracket fixed to the tool holder guide portion 18, and this bracket 29 is provided with a stopper surface 30 having a relatively large area, on which the tip of the stopper rod 28 can come into contact.

A tension spring 31 is stretched between the swinging rod 26 and the bracket 29, and constantly urges the tool holder 19 downward with respect to the tool holder guide 18.

On the other hand, 32 is a support plate fixed to the bonding arm 1, and a motor 33 is fixed to the lower surface of this support plate 32. A drive pulley 34 is fixed to the drive shaft 33a of the motor 33, and a belt 35 is stretched between the drive pulley 34 and the driven pulley 22.

A disk 3f with a slit 36 is further fixed to the drive shaft 33a. Further, a sensor body 38 having a groove formed in the support plate 32 so as to straddle the disk 37 is attached to a bracket 39.
An optical sensor 40 is provided in the groove, with a light emitting part and a light receiving part facing each other.

Next, an example of a die bonding method performed using the apparatus of this embodiment having the above configuration will be explained.

A bonding head 4 fixed on an XY child table (not shown) moves according to a predetermined movement of the XY table. Therefore, the tool 20 attached to the tip of the bonding arm 1 via the bracket 17 and the tool holder guide 18 first moves forward to just above the chip suction position M, but before that, the television camera 12 attempts to suction it. The recognition device 1 captures an image of the chip 3 and recognizes the video signal.
4 and recognize the tip angle Qc.

As described above, when the tool 20 advances to just above the chip suction position M, the bonding arm l is lowered and the bracket 17. Tool holder guide part 18 and tool holder 1
The tool 20 also descends through the tool 9 and comes into contact with the chip 3 to vacuum-adsorb the chip. During this suction, the tension spring 32 is expanded and a gap is created between the stopper surface 30 and the stopper rod 28. A pressing force equivalent to the restoring force due to the expansion of the spring is applied to the tip 3.

After adsorbing the chip, the tool 20 rises by -1° and then reaches the 1st degree.
The motor 33 moves along the arrows X1 and X2 shown in FIG. .

Then, the motor WAwJ shaft 33δ rotates by a required angle based on the calculation result, and the rotation is transmitted to the driven pulley 22 via the drive pulley 34 and belt 35.

Then, since the eccentric pin 23 swings about the central axis of the driven pulley 22, the engagement groove 24 is attached to the eccentric pin 23.
The swinging rod 26 that is engaged through the tool holder 19
It rotates by Qc~Q (when the tip and land are both tilted in the same direction) or Qc+Qw (when the tip and land are tilted in different directions) about the central axis of.

When the tool 20 reaches directly above the bonding point N, the ridgeline of the chip 3 will be parallel to the ridgeline of the land 11, so if the tool is lowered and bonding is performed, the bonding point will be as shown in Figure 1 (8). Thus, the chip 3 can be properly bonded to the lands 11.

Next, an example of a bonding method in which a collet 41 having a pyramidal surface 40 as shown in FIGS. 6(a) and 6(b) is used as a chip adsorption and bonding tool will be described.

In this case as well, as in the previous method, the collet 41 first moves forward to just above the chip suction position M, but before that, the television camera 12 images the chip 3 to be suctioned and the image is captured. Input the signal to the recognition device 14 and calculate the tilt angle Q
Recognize c.

Then, before or during the descent of the collet 41, the tool rotation means K explained in FIGS. 3 to 5 is operated to rotate the collet 41 by the inclination angle Qc, and then the chip is adsorbed. In this way, each pyramidal surface 40 of the collet 41 coincides with each ridgeline of the chip 3, so that the collet 41 can easily vacuum-adsorb the chip 3 without damaging it.

After the chip is adsorbed, the collet 41 rises by -1, and as shown in Fig. 1 (
sll] along the arrows x1 and If the chip 3 is rotated by QCNQw or Qc +Qw and then lowered from directly above the bonding point N to perform bonding, the chip 3 will be in the correct position relative to the land 11, as shown in Figure 1 (8). Bonding is possible.

〔Effect of the invention〕

As described above, the present invention recognizes the inclination angles of the workpiece and the chip, advances and lowers the tool directly above the tool suction position to suction the chip, and moves the tool to directly above the bonding point. The calculation based on the above-mentioned recognition results revealed that the bonding land was tilted because the tool was rotated to match the tilt angle of the workpiece and then the bonding was performed. Even in the case where the chip is bonded at the correct angle with respect to the land, the advantage is that the automatic continuous bonding process can be performed quickly.

[Brief explanation of drawings]

FIG. 1(A) is a plan view of a wafer and a workpiece showing an example of the method of the present invention, FIG. 1(B) is a plan view of a chip to be adsorbed, and FIG. FIG. 2 is a schematic side view of a television camera etc. used in the method of the present invention, FIG. 3 is a plan view of a tool rotating means used in the method of the present invention, and FIG. 4 is a side view of FIG. 3. , FIG. 5 is a front view of FIG. 4, FIG. 6 (A) is a sectional view of the collet, FIG. 6 (0) is a bottom view of the collet, FIG. The figure is a side view of Fig. 7, and Fig. 9 (a) to (
) is an explanatory diagram of tilt correction. 1... Bonding arm 2... Tool 3... Chip 4... Bonding arm 5... Wafer 6... Wafer ring 7
...Chip push-up mechanism 8...Push-up pin 9...
Work guide 10... Bonding point 11.
...Land 12.13...TV camera 14.15II = recognition device 16...Monitor 17...
-Bracket 18...Tool holder guide part 19...Tool holder 20...Tool 21...
- Overhang part 22... Driven pulley 23... Eccentric pin 24... Engagement groove 25... Boss part
26... Swinging rod 27... Set screw 2
8... Stopper rod 29... Bracket 31... Bow 1 Bow spring 32... Support plate 33a... Drive shaft 35... Belt 37... Disc 39... Bracket W ... Workpiece Qw ... Land inclination angle 30 ... Stopper surface 33 ... Motor 34 ... Drive pulley 36 ... Slit 38 ... Sensor body 40 ... Optical sensor Qc ... Tip angle of inclination Figure 1 (A) C Figure (B) Other 4 people Figure 2 Figure 2 0 Figure 42 - Vacuum suction hole Figure 8 Procedural amendment Heisei year? 16th of the month! , Indication of the case 1999 Patent Application No. 143250 2 Name of the invention Date 2... Table LyLl-3 Person making the amendment Relationship to the case Applicant 4, Agent Address Marunouchi, Chiyoda-ku, Tokyo 2-6-2 Marunouchi Shigesu Building 330 Amendment) The following items in the specification and drawings will be amended. 1, page 5, line 17, line 188, page 6, line 1, page 7, line 10, line 111, page 8, line 13, page 11, line 15, 's page 13, line 18 , page 14, line 2, page 17, line 8
Correct the words 'Qc J' to 'θC' in the respective lines. 2. Corrected "Qw" on page 6, line 2, page 8, line 4, line 5, line 133, page 14, line 11, and page 17, line 9, to read "θ," respectively. do. 3. On page 6, line 3, 'Qw -Qc J' is corrected to 'θ1 - θ.' 4. On page 6, line 5, 'Qc -Qw J' is corrected to 'θ0-08'. 5. r Q c + Q w J on page 6, line 8, page 12, line 10, page 13, line 1, and page 14, line 13, respectively, are replaced with “θC+
01”, corrected. 6. In the 8th and 9th lines of page 7, the words ``r wafer ring 6'' are corrected to ``r wafer ring 6.'' 7. On page 7, line 14, correct "tool 2" to read r tool 20J. 8, page 12, line 10, line 200, page 14, line 13, 'Qc-QwJ' are rθ. 〜θ,'' is corrected. 9. The words "pyramidal surface 40" on page 13, lines 11-12 and page 14, line 4 are corrected to "pyramidal surface 43." 10. Delete "2...Tools" on the 6th line of page 16. ! ! , "Figure 6 (a) in the drawing is corrected to the submitted drawing. (b) is today's figure 2 3.-Tip 42-Vacuum suction hole

Claims (1)

[Claims] 1. The inclination angles of the workpiece and the chip are respectively recognized, the tool is advanced and lowered directly above the tool suction position, the chip is adsorbed, and the recognition results are obtained while the tool is moved to the position directly above the bonding point. A die bonding method characterized by performing bonding after rotating a tool to align the tip with the inclination angle of the workpiece using calculations based on . 2. Recognize the inclination angle of the workpiece and the chip, advance the tool directly above the tool suction position, and lower it to adsorb the chip.Then, rotate the tool by the inclination angle of the chip based on the recognition above to adsorb the chip. Then, while the tool is moved directly above the bonding point, a calculation based on the recognition result is performed to rotate the tool so that the tip matches the inclination angle of the workpiece, and then bonding is performed. . A tool holder guide part (18) is integrally formed at the tip of the bonding arm, and a chip suction and bonding tool (20) is attached to the tip and slides into the shaft hole provided in the tool holder guide part. a removably mated tool holder (19);
An engagement groove (24) is provided on one side, and a stopper rod (28) is provided on the other side.
) and fixed to the tool holder; and a driven pulley (22) rotatably mounted on an overhang (21) integral with the tool holder guide.
, an eccentric pin (23) provided on the driven pulley that engages with the engagement groove, and an eccentric pin (23) that is stretched between the swinging rod and the tool holder guide section and is normally connected to the swinging rod and the tool holder. and a tension spring (31) urging the tool against the tool holder guide so that the stopper comes into contact with a stopper surface (30) provided on the tool holder guide.
and a motor (33) attached to the bonding arm (1) and having a drive pulley for rotating the driven pulley.