JP2532534B2 - Semiconductor chip pickup device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip pickup device used in a die bonder or the like of a semiconductor manufacturing apparatus.

2. Description of the Related Art Conventional chip pickup used in die bonders of semiconductor manufacturing equipment is a method of half-cutting a wafer and then picking it after break-expanding, to semi-full-cut or full-cut breaking-expanding pick-up. Is changing to.

Hereinafter, an example of the conventional chip pickup described above will be described with reference to the drawings. 4 to 6 are side sectional views showing an outline of a conventional chip pickup.
As shown in FIG. 4, a wafer 2 having a surface cut by a chip unit with a blade blade 1 of a wafer cutting device (dicing saw) as shown in FIG. 4 is attached to a sheet 3 as shown in FIG. After soaking, the sheet 3 is stretched and the outer edge of the sheet is fixed by a rubber band 4, so-called an expanded ring 5 is detachably fixed to the apparatus. Reference numeral 6 denotes a holder, which is open at the top and houses a push-up pin 7 that moves up and down. The push-up pin 7 breaks through the sheet 3 and lifts the chip 8.
Collet 9 with vacuum adsorption performance is coming down from above,
The chip 8 is picked up by suction.

Problems to be Solved by the Invention Conventionally, the cutting depth for dicing saw into a single chip is a half-cut method of about 1/2 of the wafer thickness, but the cross section of the chip 8 when broken is As shown in Fig. 6, the outer circumference is larger than the original chip size, and it is necessary to increase the size of the die pad a little when die-bonding to the lead frame. The occupancy ratio of the chip to the package is increasing. At present, it is extremely disadvantageous, and recently, as shown in Fig. 7, a semi-full-cut method that cuts the uncut thickness to less than about 1/10 of the wafer thickness, or completely separates it as shown in Fig. 8 , The number of full-cut type with a little incision on the sheet 3 is increasing. With these methods, the latter is completely separated from each other, and the former can also break with a very weak force, so the breaking process by the roller can be omitted, but the push-up pin 7 Even if you try to pick up by pushing up with, the distance C between the tips is only the thickness of the blade 1, that is, 25 to 40μ, and if the tip that is pushed up tilts slightly, it will hit the next chip and both chips will chip. At present, it is not possible to omit the expanding step of stretching the sheet 3 because of the high probability of cracking. By the way, the distance between the chips after the expansion process is 200
It is generally that there is μ or more.

In view of the above problems, the present invention does not take an extra area when a chip is cut off, and
A semiconductor chip pickup device capable of omitting the expanding step.

Means for Solving the Problems In order to solve the above problems, a semiconductor chip pickup method according to the present invention uses a first surface of a holder upper surface surrounding a push-up pin, on which a chip to be pushed up is located, and a second surface adjacent thereto. The angle θ is given to and, and the sheet is pasted on the back side of it, and the full cut or semi-full cut wafer with the specified wafer cutting width is set,
At least when the holder is located at the edge of the wafer, the protrusion β of the holder from the sheet outer periphery fixing portion causes an angle β formed by the sheet between the holder and the farthest portion of the sheet outer periphery fixing portion with the first surface. Is smaller than the angle θ, and the value of θ-β is smaller than a predetermined angle determined by the thickness and cut width of the wafer and the uncut thickness, and the protrusion margin d is set small. Then, while suctioning the sheet from the vacuum suction hole provided on the second surface of the holder upper surface, the chip on the first surface is pushed up by the push-up pin to perform vacuum suction pickup.

Effect The present invention, by the method described above, because the interval between the chip to be pushed up and the chip next to it spreads in a fan shape, the break-expanding step is omitted, and the chip is picked up in the state of being semi-full cut or full cut. I made it possible.

Embodiment Hereinafter, a semiconductor chip pickup method according to an embodiment of the present invention will be described with reference to the drawings.

1 to 3 are sectional views of a main part of a semiconductor chip pickup device according to an embodiment of the present invention. 1 to 3, a frame 11 has a function similar to that of the ring 5 of the conventional example, and the outer edge of the sheet 13 to which the wafer 12 is attached is adhered. The wafer 12 is semi-full-cut or full-cut after being attached to the sheet 13, and is in a state in which it is almost cut into individual chips. A vertically moving push-up pin 15 is housed inside a holder 14, a hole 17 through which the push-up pin 15 passes is formed on the first surface where the chip 16-1 to be pushed up is located, and a tip chip 16-1 to be pushed up.
A hole 18 for vacuum suction is formed in the second surface on which the adjacent chip 16-2 is located, and vacuum suction is performed in synchronization with the push-up pin 15 pushing up from the suction port 19 in the middle abdomen of the holder 14. Further, an angle θ is provided between the first surface and the second surface.
20 picks up and picks up a chip pushed up by a collet that has vacuum suction performance.

The chip coming on the holder is broken by the angle provided on the first surface and the second surface of the holder upper surface, and the push-up pin 15 breaks through the sheet 13 and lifts the chip 16-1, and at the same time, the adjacent chip (actually, the adjacent chip The sheet to which the chips are attached) is vacuum-sucked so that it is sucked onto the upper surface of the holder and only the target chip 16-1 is pushed up and picked up by the collet 20 from above. Therefore, according to this embodiment, since the angle θ is provided between the first surface of the upper surface of the holder where the chip to be pushed up is located and the second surface where the chip adjacent to it is located, the break process of the semi-full cut product is automatically performed. In addition, the chip-to-chip spacing spreads out in a fan shape, so even if the expanding process is omitted, pick-up is possible without chipping or cracking due to contact between chips.

Further, not only the above effect is further secured by the hole for vacuum suction provided on the second surface, but also the push-up pin
It became possible to dramatically lengthen the service life period until the sheet 13 is pierced due to abrasion of the tip of the sheet 15.

By the way, the angle θ is also related to the blade thickness (≈C) of the dicing saw, but in the worst condition, in other words, when the blade thickness is the thinnest, for example, in the case of semi-full or full cut, the blade thickness is 25μ. The degree is the worst condition, but even at that time, if θ is 3 ° or more, the break will be complete and chipping when pushing up the chip,
The occurrence of cracks can be almost prevented.

However, it is theoretically correct that the incidence of cracks and cracks decreases as θ increases, but in reality, if θ is increased too much, the phenomenon of cracks and cracks increases, and the cause is Examination revealed that there was no chipping or cracking due to contact between the tip 16-1 to be pushed up and its adjacent tip 16-2, but as shown in FIG.
-2 and the chip 16-3 next to it, chipping due to contact,
It was found that a crack had occurred.

FIG. 3 shows the state where the chips are in contact with each other when the chips are attached to the sheet 13. The inclination α of one chip at the time of contact is the wafer thickness a, when the wafer is cut. Is determined by the uncut thickness b of b (b = 0 when full cut) and the cutting width (≈blade thickness) C, Becomes Therefore, in order to prevent the contact between the chips 16-2 and 16-3, θ-β <α.

Where β is the angle shown in Figs.
Is at the edge of the wafer 12, and the wafer diameter is e, the sheet outer peripheral fixing portion diameter is f, that is, the inner diameter of the frame 11 is f, and the protrusion amount of the holder from the sheet outer peripheral fixing portion is d. Is represented by

From the above In that case, cracking and chipping due to contact between the chips 16-2 and 16-3 can be prevented, and this was confirmed experimentally. An example will be shown below.

Experiment Use 1.6 inch wafer a = 400 (μm), b = 30 (μm), c = 30 (μm), d = 3
(Mm), e = 150 (mm), f = 190 (mm), α + β ≈ 5.66 (degrees) No cracks or chips when θ = 5 (degrees), 100 chips in the case of θ = 6 (degrees) Small chip occurred on 22 chips.

Experiment 2.5 inch wafer use a = 300 (μm), e = 125 (mm), f = 165 (mm), others are the same as Experiment 1. At that time, α + β≈7.57 (degrees) No cracks or chips when θ = 6 (degrees), and small chips occurred on 18 of 89 chips when θ = 7 (degrees).

Although θ can be increased by increasing the protrusion amount d of the holder from the outer peripheral portion of the seat as much as possible, if the d is too large, the frictional resistance between the holder 14 and the sheet 13 increases and the sheet 13 is broken, Be careful because the sheet 13 may come off from the frame 11.

As described above, according to the present invention, even if the break / expand step is omitted, chipping due to contact between the chip to be pushed up and its adjacent chip, generation of cracks, and the chip next to the chip are also prevented. It is possible to prevent chipping and cracking due to contact with the sheet, and also to prevent the sheet from breaking or coming off due to frictional resistance between the holder and the sheet. As a result, not only cost reduction can be achieved, but also stable quality is obtained. Furthermore, since the pitch between chips is constant, the feed can be performed at a constant pitch, which is inexpensive. The device can be realized.

[Brief description of drawings]

1, 2, and 3 are cross-sectional views of an essential part of an embodiment of the present invention,
FIG. 4 is a schematic view at the time of cutting a wafer, FIG. 5 is a cross-sectional view of a main part of a conventional example, FIG. 6 is an enlarged cross-sectional view of a chip after half-cutting, break / expand, and FIGS. 7 and 8 are semi-full-cutting. FIG. 3 is an enlarged view of a chip cross section of a full cut product. 13 …… Sheet, 14 …… Holder, 15 …… Push-up pin,
18 ... Vacuum suction hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Takaoka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References: 62-170637 (JP, U) 135432 (JP, U)

Claims (2)

(57) [Claims] 1. A pin that pushes up a chip and a holder that surrounds the pin and mounts the chip, the first face on which the chip is located and the first face on the upper surface of the holder that is adjacent to the first face, and immediately before the chip is fed. The first surface is attached to the back surface by attaching a sheet to the back surface with a first angle to the second surface, and a full-cut or semi-full-cut wafer with a predetermined wafer cutting width is set on the upper surface of the holder. When the sheet is located at the end of the sheet, the protrusion between the holder and the seat outer periphery fixing portion causes the sheet between the holder and the farthest portion of the sheet outer periphery fixing portion to form the second surface which is the first surface. The angle is
Smaller than the first angle and the first angle
And the second angle is smaller than the predetermined angle determined by the thickness of the wafer and the cutting width, and the uncut thickness, the protruding margin is set small,
A semiconductor chip pickup device having a mechanism of pushing up a chip on the first surface with the pin while sucking a sheet portion on the second surface from a vacuum suction hole provided on the second surface of the holder upper surface. 2. A wafer thickness is a, an uncut thickness is b when a wafer is cut, a cutting width is C, a protrusion amount from a sheet outer peripheral fixing portion of a holder is d, a wafer diameter is e, and a sheet outer peripheral fixing portion. Letting the diameter be f, the angle θ formed by the first surface and the second surface of the upper surface of the holder is The semiconductor chip pickup device according to claim 1, wherein