JPS5982736A - Method and apparatus for wire bonding of semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an improved wire-landing method and apparatus, and more particularly, the present invention relates to an improved wire-landing method and apparatus, and more particularly, the present invention relates to an improved wire-landing method and apparatus that recognizes the position of a semiconductor device in a first working section and moves the semiconductor device to a second working section. The present invention relates to an improved wire bonding method and apparatus for performing wire bonding.

(Technical background of the invention and its problems) Guipon is applied to the semiconductor chip mounting area of a ribbon lead frame, the chip mounting area of a ceramic cage with a lid, or the chip mounting area on an insulating substrate on which external wiring leads are formed. The bonded semiconductor device is bonded to an electrode lead-out portion (hereinafter sometimes referred to as a bonding pad) on the surface of the wire by a device called a bonding device.

) and the external lead portion are interconnected with a thin metal wire.

In recent years, these connection points have been arranged very closely together and are also very large in number. Therefore, the recognition of these positions is automated by an electro-optical scanning eye, as a slight deviation can disturb the yy-binding position and cause short circuits, incorrect wiring or damage to the device surface. It can perform wire bonding much more accurately and at higher speeds than the human eye wire bonding devices of a generation ago. However, current devices are still unsatisfactory in terms of speed. That is, in the conventional bonding method, after supplying the semiconductor devices to a bonding work area, the electro-optical pattern recognition device processes the semiconductor devices that have been supplied. This is done by comparing the turns with a reference pattern to recognize the position of the semiconductor device, and bonding the interconnection points based on this recognition information.

According to this method, the operation of the pounding needle is kept on standby until the position recognition of the supplied semiconductor device is completed, and this waiting time prevents high-speed operation. Furthermore, while position recognition is being performed, the pounding needle, which was waiting at a position outside of this field of view, is now within the optical field of view.
It takes time for the pick to move to the starting position for bonding the semiconductor device.

If it is possible to recognize the position of the semiconductor device by the recognition device in the first working section and perform the pounding operation with the pounding needle waiting at the scheduled pounding start position in the second working section. .

The time required for the wire pounding needle to start operating is the time required to move from the first working section to the second working section, except for the first one. This is because position recognition in the first work section and transfer of this position recognition information can be completed during wire bonding in the second work section.

The prerequisite for this method is that there is no shift in the transfer of semiconductor devices from the first working section to the second working section (6). However, since the transfer of semiconductor devices is carried out by a mechanical moving device, a feed deviation of a much larger distance than the wire bonding accuracy (for example, 0.0151+tm) may occur, and position recognition in the first work zone may occur. As a result of the information being useless and requiring relocation in the second workstation, wire ending time reductions are often not as significant as expected.

(Object of the invention) The object of the invention is to add
An object of the present invention is to provide a semiconductor wire-dending method and an apparatus therefor, which are speeded up by applying certain techniques.

Hereinafter, two embodiments of the present invention will be described in detail based on the drawings.

(Embodiments of the Invention) Figures 1A to 1C are plan views showing several examples of processed products used in the wire pounding method and device of the present invention;
・FIG. 2 is a diagram showing an embodiment of the wire bonding ink method and apparatus of the present invention, and FIG. 3 is a diagram of a second embodiment of the invention. In FIG. 1A, a semiconductor chip 2 is mounted on a metal thin plate 1 called a lead frame or a lead frame in an area located approximately in the center of the thin plate in a process called die bonding, and the semiconductor chip 2 is mounted in an area located approximately in the center of the thin metal plate 1, which will be described later. According to the wire ending method and apparatus, each of the plurality of electrodes (commonly called bonding pads) on the surface of the semiconductor chip and the free ends of the external leads 3 concentrated in the vicinity of the semiconductor chip mounting area are made of thin metal. connected by a line. In addition, in the omitted X-axis direction, 10 to 20 consecutive patterns surrounded by dashed-dotted lines are provided. In addition, the code|symbol 4 is an index hole.

FIG. 1B shows what is called a chip-on-board (COB), in which a conductor 5 forming an external IJ-board is formed on the main surface of an insulating substrate 4a, and a semiconductor chip 2 is placed approximately in the center of this substrate. As explained in FIG. 1A, the bonding pads of the semiconductor chip and the conductive paths forming the external leads are connected by thin metal wires. 1st C
The figure is also a plan view of a workpiece which is subjected to the method of the invention and has a semiconductor chip 7''2 inserted into a recess approximately in the center of the ceramic mold cage 6.

Next, referring to FIG. 2 which is an embodiment of the present invention, reference numeral 11 denotes a turntable which rotates by a rotation angle (90° in this embodiment) determined by a drive device (not shown) and then stops. It is driven intermittently. The turntable 11 is therefore divided into four working sections. The first work section is indicated by the symbol A and is a work section that supplies the workpiece shown in FIG. It is installed at the periphery of the first stop position of the table 11.

The processed product supply device 13 has an arm 14 having an electromagnet at its tip.
holding the magnetic metal thin plates J (see FIG. 1A) made of copal one by one through the position indexing bin 16 of the fixing jig 12.
Supply it by loading it into the container. The second working section is indicated by a code entry, and contains the supplied workpieces, semiconductor (9) of semiconductor chip mounting area of serial lead frame 1, and semiconductor chip 2 die-bonded to the chip mounting area.
This is a position recognition work section that recognizes the mutual positions of the leading pads of the lead frame 1 and the external leads of the lead frame 1, that is, the wire ends, by indexing them from the reference position. 2. It is installed on the periphery of the stop position. The position recognition device 16 is
- It has a scanning eye 18 (hereinafter also referred to as a television camera) installed on the Y table 17, and this scanning eye 18 is connected to a plurality of semiconductor chips 2 mounted on the tray 12.
It is located above the tray 12 so as to be able to project the image within the optical field of view, and is installed so as to be able to move two-dimensionally on the tray 12 and to recognize the mutual wire bonding positions of the plurality of semiconductor chips 2. There is. The third work section is designated by the symbol C, and is a bonding work section where wire bonding is performed on a plurality of semiconductor chips 2Vc transferred together with the tray 12, and includes a wire ending device J 9 and the turntable 1. It is installed at the periphery of the third stop position. The wire (10) ear bonding device 19 used for this purpose is a device called a well-known pole bonder or a nail bonder, and is used to place a ball formed by applying heat to the tip of the entire wire at the bonding position. Wire punching can be performed by pressing. This wire bonding device 19 has a head 2 installed on an XY table 20 in order to wire bond all of the semiconductor chips f2 mounted on the tray 12 to the external leads 3 of the lead frame 1. Was this wire ending work recognized in the second work area?
Bonding is performed based on bonding position information obtained by adding position correction information, which will be described later, to bonding mutual position recognition information. The above position correction information is issued by the scanning eye 23 of the position recognition confirmation device 22 installed in this third work section.

This position recognition/confirmation device 22 includes the turntable 11
is to check whether or not the rotation by the set angle from the stop position of the second work section to the stop position of the second work section has been executed, and the movement reference position on the tray 12 in the second work section is checked. A television camera 23 is positioned above the tray 12 so as to be able to image the tray 12 or the semiconductor chips 2 on the tray 12 within an optical field of view in order to receive information and detect whether the tray 12 is being moved too much or too little; It is installed on an X-Y table 24. Moreover, this position recognition confirmation device 22.
The position recognition device 16 and the wire bonding device 19
is connected to a cable (not shown), and transfers bonding mutual position recognition information in the second working section to the wire bonding device 19 and position recognition confirmation bag #22 by a known method, and this position recognition device 16 The wire bonding is performed at a desired position by adding information on the amount of movement of the turntable 11 to the wire bonding mutual position information.

The fourth work section is designated by the reference numeral 2, and is a work section for discharging the lead frame 1 after wire winding. A processed product discharging device 26 for magnetically attracting and ejecting the processed product is installed. The workpiece discharging device 26 and the workpiece supplying device 13 are designed so that when the workpiece does not have a base member made of a magnetic material as shown in FIG. 1B or 1C, the tip of each arm 14°250 is It would be better to replace it with an electromagnet and create a mechanism that grips and lifts multiple workpieces at once.

Therefore, the processed product is placed in the recess 28 of the jig 2z as shown in Figure 3.
The workpieces may be lined up and the holes 29 may be loaded into the position indexing pins 15 of the fixing jig 12.

Now, the method of the present invention will be explained while also explaining the operation of the apparatus of the present invention shown in FIG. The processed product supply device 13 is a tray 1 on which processed products, that is, lead frames 1 are stopped in a first working section A.
Set to 2. It is convenient to install a position index pin 15 in the train 2 to engage with the position index hole 4 of the lead frame 1. Also, this tray 1
Although not shown in FIG. 2, a holding device 2 for fixing the lead frame 1 presses the peripheral portion of the frame 10.

This prevents the tray from moving when the tray 12 is moved.

Of course, it goes without saying that this presser tool operates after the frame 1 is set. Is this kind of movement of the presser in the second working section? It is only necessary to complete the process before starting recognition of the mutual landing position (13). When the workpiece supply operation in the first working section is completed, the turntable 1 transports the tray 12 from the first stopping point to the second stopping point. Since the turntable 1 is divided into four working sections, each stopping point position is 90°, 1800.270'
and 36o0 (oo). The shaft of the turntable 11 stops at the second work compartment opening stop point (second stop point), which is a position rotated by 90 degrees from the first stop point. When the plurality of semiconductor chips mounted on the tray 12 are transferred to the second working compartment opening and the lead frame l is fixed to the tray 12 by a presser (not shown), the scanning eye 18 of the first position recognition device 16 is placed on the tray 12. Coordinates of the bonding pads of each semiconductor chip 2 and each external lead 3
Recognize the coordinates of the bonding position and 1
, are sequentially stored as position recognition information in a register (not shown). At the same time, the scanning eye 18 recognizes a predetermined movement reference position coordinate at an arbitrary position on the tray 12, and this recognition information is also stored in the register. As the movement reference position, one of the plurality of (14) wire bonding position recognition coordinates may be used, but since wire bonding and hoods usually have the same pattern, the die bond position may vary widely. If it deviates, it is easy to misidentify it, so it is better to avoid it. A large number of wire ending positions can be recognized by the scanning eye 18 by determining the distances along the X and Y axes from the measurement reference point of the measurement system of this recognition device as coordinates. Therefore, there is no restriction that either the movement reference position or each pounding mutual position must be recognized first.

However, since the wire pounding order of the wire ending device, which will be described later, is designed to be performed in a predetermined order, the output from the register can be used as is as wire ending information if it is recognized in that order.

The mutual bonding position and movement reference position of each semiconductor chip in the television camera 18 are recognized by comparing the bonding/mother turn within the optical field of view with the same reference/gutter, and determining the X coordinate of the matching point. and the X coordinate. When all the Dending position coordinates on the tray 12 have been continuously recognized and the plurality of X coordinate signals and the The semiconductor chips 2 on the tray 12 are transferred to the stopping point (third stopping point) in the work section C. It should be noted that since the plurality of semiconductor chips 2 are transferred with each tray 12, the mutual bonding positions between the bonding A and the external leads 3 of each semiconductor chip 2 change frequently. The only position change is turntable 11
is not rotated at the set rotation angle, resulting in excess or deficiency, and the movement reference position deviates without stopping (arriving) at the planned movement position.

Therefore, it is only necessary to detect the deviation and correct the X and X coordinate signals of the respective bonding mutual positions recognized at the second working compartment opening. Therefore, each semiconductor chip 2 and external lead 3 on the turntable 11 stopped in the third working section C.
Before the wire ends with the wire ending device 19, the position recognition confirmation device 22 recognizes the actual position of the moving reference position relative to the expected arrival position, and outputs an error signal (hereinafter sometimes referred to as a correction signal). Occur. Since this error signal is caused by excess or deficiency of rotation, it is sufficient to calculate Δθ and correct the difference Δθ.

To explain this using FIG. 4, let xP and yP be the coordinates of point P, the expected arrival position after movement when the arbitrary movement reference position on the tray 12 recognized at the second work area entrance is rotated by θ. , Similarly, the recognition position (
91 scheduled arrival (rest) positions after these movements when the multiple points) have also rotated by θ...The coordinates of the Qn points are xQl + 3'Ql -xQn, yQn, respectively, and the turntable 11 is further rotated. The position recognition confirmation device 22 detects the actual position of the movement reference position, that is, the coordinates xP of a position P' shifted by Δθ.
If only '+yP' is recognized, the rotational deviation angle Δθ can be determined by linear equation (1).

Δθ=tan-1yp-1po...
(1) an xP xP ' Therefore, by substituting Δθ of
The actual stopping position of the tube and each external lead in the third working section C (17), that is, the position after movement Q1'...Q
Coordinates of point d XQI'yQt' -xQr/ +
yQn' can be found.

xQ1'= XQ+ e08Δθ−yQt sinΔθ
・・・・・・(2) yQx' = yQt cosΔ
θ−XQ1sinΔθ ・・・・・・(3)xQe x
Qn cos Δθ −yQn sin Δθ
−...(2) yQn' =, yQn cosΔθ−x
Qn sin Δθ −・−・−(3) When an error is detected by the position recognition confirmation device 22 of the third work area C in this way, it is recognized at the second work area entrance and stored in the register. A plurality of X-coordinate signals and bonding mutual position recognition information such as the ding. When wire bonding is completed for all of the plurality of semiconductor chips 2 mounted on the tray 12, the turntable 11 rotates by 900 degrees from the third stopping point to the fourth stopping point and moves to the fourth work section. Second tray 1
carry 2.

This fourth work section 2 is a discharge work section, and is
) The workpiece is discharged from the tray 12 by the one-piece discharge device 26, and the tray 12 is emptied and prepared for supplying the workpiece to the first work zone A. In order to remove the processed product, that is, the lead frame 1 from the tray 12, this processed product discharge device 26 uses an arm 25 having an electromagnet at its tip, as in the previously described processed product supply device 13, to magnetically attract and eject the lead frame 1. do. These arms 14 and 25 are arranged, for example, on the tray 12.
The lead frame 1 is moved up and down by an elevation mechanism in order to eject the J-de frame 1, and then rotated in an arc to complete the wire binding in a basket (not shown).
operation to store or remove the lead frame to be wire bonded from the basket.

(Effects of the Invention) As described above in detail, according to the method and apparatus of the present invention, the wire bonding time described below can be significantly shortened. That is, the total wire bonding time of a conventional automatic wire bonding machine for, for example, a 14-pin molded integrated circuit device, is determined by the time of the position recognizance device, the time of leaving the work area of the machine, and the time of the wire bonding head. The time to reach the work area is 0.25 seconds,
The transfer time from the position recognition device to the wire bonding device is 0.3 seconds, and the wire bonding time is 0.25 seconds.
sec/1 bottle, so for 14 bins it would be 3.5 sec, and the total working time would be 4.05 sec. Therefore, the total time required for ten wire bonding of the integrated circuit device is 40.5 seconds.

- In the Rikiki invention, one of the integrated circuit chips is placed on a tray.
If 0 pieces are placed, the total time required for wire bonding for 1 piece is 3.555 seconds. Since 4,910 pieces are transferred at once, the transfer time per piece is 1/10, and the re-recognition time is also 1/10. Therefore, it is possible to reduce the time by about 10% per piece. As is well known, in this field, highly versatile integrated circuit devices such as 64-bit random access memory are produced on a scale of millions of units per month, so this time reduction is extremely significant. It is something that can generate big profits.

A further significant benefit is the high-yield manufacturing method. In other words, in the conventional method of manufacturing a molded integrated circuit device using a wire bonding device, the feed claw is inserted into the index hole of the lead frame and pulled on the rail, so that the lead frame is partially exposed after wire bonding. It often happens that some songs are broken. The disadvantage of this bending is that adjacent external leads may be shortened or disconnected. Moreover, the outer shape of the frame may be deformed and the automatic machine may even stop operating. These various troubles are most undesirable because they significantly reduce the yield of semiconductor integrated circuits and also reduce the operating rate of the wire bonding device. However, since the method of the present invention does not include the step of pulling the lead frame, the above-mentioned inconvenience does not occur.

[Brief explanation of drawings]

FIGS. 1A, 1B, and 1C are plan views of a workpiece to be subjected to the wire winding method of the present invention. FIG. 2 shows wire bonding (21
) A schematic plan view of the device, FIG. 3 is a perspective view of a jig on which a plurality of processed products shown in FIG. 1C are placed, and FIG. FIG. 1... Lead frame, 2... Semiconductor chip, 11
...Turntable, 12...Fixing jig (tray)
, 13... Processed product supply device, 16... Position recognition device, 18.23... Scanning eye, 19... Wire bonding device, 22... Position recognition confirmation device, 26...
Processed product discharge device. (22) Procedural amendment (voluntary) 1. Indication of the case 1982 Patent Application No. 192540 2 Title of the invention Wire bonding method and apparatus for semiconductor devices 3 Person making the amendment Relationship to the case Patent application Person address (
Address: 105) 1-7-12 Toranomon, Minato-ku, Tokyo
Office (〒105) No. 12-12, 1-7, Toranomon, Minato-ku, Tokyo Contents of the amendment Amended as shown in the attached sheet 6 Contents of the amendment (1) Formulas in lines 5 and 7 of page 18 of the specification ( 3
) are corrected as follows. yQ+'''yQtcosΔθ+XQ+sinΔθ −
(3) yQn' −yQn00sΔθ+XQnsinΔ
θ - (3) (2) "Operating rate" on page 21, line 12 of the same book is corrected to "operating rate." (2)

Claims (2)

[Claims] (1) A wire ending method in which the ending pads and external leads of a semiconductor device are interconnected by a thin metal wire, including: (a) arranging a plurality of the semiconductor devices on a tray;
and transferring the tray to a first work area. (b) fixing the mutual positions of the semiconductor devices on the tray, recognizing the wire bonding position of each semiconductor device from the reference position, and setting a movement reference position; (c) setting a stopping position in a second working compartment for transferring the tray from the first working compartment to the second working compartment; (d) After the recognition of the wire bonding position of each semiconductor device from the reference position and the setting of the movement reference position are completed, the tray is moved to the first position based on the stop position setting information.
and a step of transferring from the working section to the second working section. (,) correlating the stop position setting information with the movement reference position setting information, checking the actual position of the movement reference position on the tray in the second work section with respect to the scheduled stop position, and checking whether the tray is being moved too much or too little. and the process of detecting. (f) Correct the wire ending position recognition data of each semiconductor device in the first working section based on the tray transfer excess/deficiency detection data, and adjust the required wires to each semiconductor device based on the corrected data. 1. A wire ending method for a semiconductor device, the method comprising the step of performing bonding. (2) In a wire bonding device that interconnects bonding pads and external leads of semiconductor devices with thin metal wires, (,) a plurality of the semiconductor devices are mounted and the mutual positions of the semiconductor devices are fixed. With a tray. (b) The trays are installed on the periphery of a turntable that is equally divided into a plurality of work sections. (c) an intermittent drive device that moves and stops the turntable for each work section; (d) a processed product supply device that supplies a semiconductor device installed at a peripheral edge of a first working section of the working section where the turntable is stopped; (e) It is located at the periphery of the second working section of the working section, and is installed so that each semiconductor device on the tray stopped in the second working section can be seen within the field of view, and each semiconductor device from the reference position of the measurement system is A position recognition device that recognizes a wire bonding position of a semiconductor device, generates a recognition signal, sets a movement reference position, and generates a setting signal. (f) A measurement reference point of the measurement system, which is arranged at the periphery of the third working section of the working section, and is located above the tray so that each semiconductor device on the tray stopped in the third working section can be photographed within the field of view. a position recognition confirmation device arranged so as to be able to detect a deviation of the movement reference position from the expected arrival position by associating the movement reference position with a measurement reference point of the position recognition device; (g) a wire bonding device that two-dimensionally corrects the recognition signal recognized by the position recognition device in accordance with an error signal emitted from the position recognition confirmation device, and performs the required wire bonding on the semiconductor device; . (h) A wire ending device, which includes a workpiece discharging device disposed at a peripheral edge of a fourth work zone of the work zone, for discharging a workpiece transferred to the fourth work zone and having undergone wire bonding.