JP2000323504A - Collet for adsorbing semiconductor chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a collect for adsorbing a semiconductor chip that does not collet silicon dust and so on, which spatter onto a wafer, in the center of a chip surface. SOLUTION: A collet 10 for adsorbing a semiconductor chip comprising an adsorbing surface 10a, which opposes via a minute gap a surface of the semiconductor chip to be adsorbed and adsorbing holes 12 which open to the adsorbing surface 10a, wherein a plurality of minute projections 11 forming the minute gap are formed at the outer edge of the adsorbing surface 10a. In this case, the adsorbing holes 12 are provided on two or more places on the outer edge other than the center of the adsorbing surface 10a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a collet for adsorbing semiconductor chips. More specifically, the present invention relates to a semiconductor chip suction collet for chip transfer (conveyance) in a die bonder or the like.

[0002]

2. Description of the Related Art Conventionally, in a die bonding process of mounting a semiconductor chip on a package, a lead frame, or the like, a semiconductor chip for suctioning a semiconductor chip cut out from a wafer by a die bonder and transferring it to a predetermined bonding position. Collets are known.

FIG. 10 is a schematic view of a conventional die bonder,
FIG. 11 is an explanatory diagram of a die bonding step accompanying movement of a chip in the die bonder of FIG. 10 and 1
As shown in FIG. 1, a die bonder 1 which is a semiconductor assembling apparatus picks up chips 3 of a diced wafer 2 one by one by a pick-up collet (sucking collet) 4 and transfers them as shown by arrows A → B → C. do it,
It is bonded to a lead frame or package 6 to which the adhesive 5 has been applied.

In the step of bonding the chip 3 after dicing to a lead frame or the like by the die bonder 1,
The chips 3 (see FIG. 11) sucked by the pickup collet 4 one by one together with the pickup collet 4
The package 6 is transferred to a package 6 (see FIG. 10) which is transported to a transport carrier (not shown) moving on the transport line, and is placed.

[0005] The pickup collet 4 is provided with one suction hole 8 (see FIG. 11) which is opened substantially at the center of the bottom surface (suction surface).
A state where the pickup collet 4 is almost in close contact with the upper surface of the chip 3 via a minute protrusion 4a of about 0.05 mm on the bottom surface (a state where the pickup collet 4 is opposed to the chip 3 via a minute gap formed by the minute protrusion 4a).
Then, the pressure is reduced through the suction holes 8 so that the chips 3
Is vacuum-adsorbed to the pickup collet 4 (see FIG. 11).

[0006] The chip 3 mounted on the package 6 is pressed from above the adhesive 5 attached to the package 6, and is adhered to the package 6 via the adhesive 5. After the bonding of the chip 3, the vacuum is broken by releasing the reduced pressure to eliminate the chip suction state (see FIG. 11), and the chip 3 is left on the package 6 and only the pickup collet 4 returns to the diced wafer 2. I do.

[0007]

However, in the case of the above-described conventional pickup collet 4 in which the chips 3 are attracted, the pickup collets 4 are brought into direct contact with the wafer 2 after dicing to pick up the chips 3 one by one. At the time of suction, silicon dust or the like scattered on the wafer 2 adheres to the chip 3.

At this time, silicon dust and the like scattered on the wafer 2 are collected at the center of the surface of the chip 3 because the suction hole 8 is formed substantially at the center of the bottom surface (suction surface). Therefore, for example, a charge-coupled device (charge
e coupled device (CCD)
Since an effective pixel, which is a light detection sensor unit, is located at the center of the surface of the chip 3, silicon dust and the like will adhere to this effective pixel.

At present, in the process of assembling a special semiconductor such as a CCD, the attachment of minute dust (dust) of about 1 μm to 10 μm to a product is a fatal defect, and the adhesion of dust causes the product to be defective. Therefore, it is not an exaggeration to say that improving the quality of a CCD or the like, that is, improving the yield, is dust improvement.

It is an object of the present invention to provide a semiconductor chip attracting collet which does not collect silicon dust and the like scattered on a wafer at a central portion of a chip surface.

[0011]

In order to achieve the above object, according to the present invention, a suction surface facing a surface of a semiconductor chip to be suctioned through a minute gap and a suction hole opened in the suction surface are provided. In a collet for semiconductor chip suction having a plurality of minute projections for forming the minute gaps formed on a peripheral portion of the suction surface, the suction holes are formed in a plurality of peripheral portions other than a central portion of the suction surface. A collet for adsorbing semiconductor chips, provided at a plurality of locations.

With the above structure, a semiconductor chip suction collet used for bonding a chip to a package or the like, which sucks the chip, is provided through a plurality of suction holes arranged in a peripheral portion other than a central portion of the suction surface. The pressure between the chip surface and the suction surface facing the chip is reduced. This prevents silicon dust and the like scattered on the wafer from being collected at the center of the chip surface.

Further, according to the present invention, there are provided a suction surface opposed to a surface of a semiconductor chip to be sucked through a minute gap, and a suction hole opened in the suction surface, and a plurality of holes for forming the minute gap are provided. In the semiconductor chip suction collet in which the micro projections are formed on the periphery of the suction surface, the suction hole is formed such that the edge portion opening on the suction surface is a straight through hole having the same diameter with no step. A collet for adsorbing a semiconductor chip is provided.

According to this structure, since the suction hole is formed by a straight through hole having the same diameter without providing a counterbore or the like on the suction surface side, the suction hole is formed in the gap between the suction collet and the chip during chip suction. The sucked air flow is sucked at a high speed without being decelerated by the area expansion such as the counterbore at the suction hole entrance, so that the dust falls off the flow due to the slow flow at the suction hole entrance and the chip surface Is prevented from adhering to.

In a preferred configuration example, in addition to the suction hole, a vacuum breaking pipe for breaking vacuum suction due to reduced pressure is provided.

According to this configuration, two systems, one for vacuum suction and the other for vacuum break, are branched and independently provided inside the collet. Unlike the case where switching is performed at the time of vacuum release and commonly used, dust once adsorbed in the piping does not return to the chip surface and adhere again.

Further, if there is a collet mounting part made of a separate member provided with a vacuum breaking pipe for breaking the vacuum suction caused by the reduced pressure, which is communicated with the suction hole, the structure can be made simple in processing.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a semiconductor chip attracting collet according to a first embodiment of the present invention.
Is a bottom view, (b) is a side view, and (c) is a front view. 2A and 2B show a state in which the suction collet of FIG. 1 is mounted on a mounting plate, wherein FIG. 2A is a plan view and FIG. 2B is a front view.

As shown in FIG. 1, a semiconductor chip suction collet (pickup collet) 10 is formed in a cubic shape. On a rectangular bottom surface 10a serving as a suction surface, four small projections 11 are provided instead of a center. Two suction holes 12 in the periphery
(See (a)).

The fine projections 11 are located at the four corners of the bottom surface (suction surface) 10a along the opposing sides and protrude by about 0.05 mm. Each of the suction holes 12 is circular or oval substantially perpendicular to the bottom surface 10a. The openings are formed in a shape or the like, and each is located substantially at the center of one half of the bottom surface 10a ((a)).
reference). Each of the suction holes 12 is, for example, separated by about 1 mm from both sides of the bottom surface 10a having a width of about 4.2 mm, and the both suction holes 12, 12 are separated by about 2.2 mm.

As shown in FIG. 2, the suction collet 1
Numeral 0 is attached to almost the center of the surface of the thin rectangular mounting plate 13 (see (a)), and the mounting plate 13
Has a counterbore 14 (see (b)) having a depth approximately half of the thickness of the counterbore. The counterbore 14 is for mounting a vacuum pipe on the die bonder side.

In the die bonding step of bonding the diced chips to a lead frame or the like by a die bonder, the suction collet 10 sucks the chips one by one, and transfers the sucked chips to a transport carrier moving on a transport line. It is transferred and placed on a lead frame or package to be transported. The chip mounted on the package or the like is bonded to the package or the like with an adhesive (see FIGS. 10 and 11).

FIG. 3 is an explanatory view showing another example of the suction holes provided in the suction collet of FIG. As shown in FIG. 3, the suction collet 10 has four corners of the suction surface (bottom surface) 10a along the opposing sides as shown in FIG.
In the case where four elongated suction holes 12 are provided in the vicinity of, or in the case where four suction holes 12 which are located substantially at the center of each opposite side of the suction surface 10a as shown in FIG. And (c)
In the case where the two suction holes 12 are further expanded outward from the example of FIG.
Various examples in which is provided not in the center of the suction surface 10a but in the peripheral portion are possible. Also, the shape of the suction hole 12 can be a perfect circle, an oval, or any other shape.

In the process of assembling a special semiconductor such as a CCD, scratches and dust are generated when the suction collet 10 for moving and placing the chip comes into contact with the light detection sensor portion (effective pixels) on the chip. Then, it becomes a fatal defect for an effective pixel.

FIG. 4 is a plan view of the chip showing the chip suction surface of the CCD. As shown in FIG. 4, in the case of a CCD, most of the chip 15 except the peripheral portion is a light detection sensor unit (effective pixel) 16. For this reason, the movement or mounting of the chip 15 in the die bonding step or the like requires the chip 1 at only four portions (for example, the contact portion 17) other than the effective pixels 16.
At present, the chip 15 is supported and sucked by contacting the five surfaces, and only a suction collet that does not contact the effective pixel 16 of the chip 15 can be used. In such a situation, when a suction collet (see FIG. 11) having a suction hole formed substantially at the center of the bottom surface is used, a small gap (approximately 0.05 mm), and an air current flows from the periphery of the chip 15 toward the suction hole at the center of the suction surface. This air current entrains dust remaining in the groove after dicing and dust adhering to the surface of the chip 15 during pickup, and collects dust at the center of the suction surface. As a result, if dust remains on the effective pixels 16, even if there is no flaw, the remaining dust causes a defective product. This is a suction collet 10 comprising a plurality of suction holes 12 provided at a position other than the center of the suction surface 10a according to the present invention.
(See FIGS. 1 and 3).

FIG. 5 is a sectional view showing a state in which the suction collet of FIG. 1 is positioned on the chip. As shown in FIG. 5, a small gap (about 0.05 mm) is provided between the surface of the chip 15 and the suction surface 10a of the suction collet 10 during chip suction.
mm), and an air current flows toward a plurality of suction holes 12 provided at a position other than the center of the suction surface 10a. This airflow is
Dust remaining in the groove after dicing and dust adhering to the surface of the chip 15 during pickup are involved. That is, by adsorbing through the two suction holes 12 located not on the center of the chip 15 but on the outer peripheral portion, it is possible to prevent dust from adhering to the center of the chip 15 (on the effective pixel 16).

Thus, it is possible to obtain a suction collet that does not cause dust to adhere to the circuit forming surface or the effective pixel surface of the chip 15, and generates a defective chip due to semiconductor dust or a die bonder due to dust. Can reduce equipment troubles on the device side, and improve the quality and yield of special semiconductors such as CCDs.

(Second Embodiment) FIGS. 6A and 6B show a semiconductor chip suction collet according to a second embodiment of the present invention, wherein FIG. 6A is a bottom view, FIG. 6B is a side view, and FIG. ) Is a front view. 7A and 7B show a state in which the suction collet of FIG. 6 is mounted on a mounting plate, wherein FIG. 7A is a plan view and FIG. 7B is a front view.

As shown in FIG.
The suction hole 12 is formed as a straight through hole of the same diameter, which is substantially perpendicular to the suction surface of the chip 15 without performing counterbore processing on the tip of the suction surface 18a. As shown in FIG. 7, the suction collet 18 is attached to the surface of the thin rectangular mounting plate 13 at substantially the center (see (a) and (b)).

In the case of the suction collet used for the CCD, since the contact surface with the chip is provided on the outer periphery of the chip other than the effective pixel, the suction surface 18a of the suction hole 12 is intended to stabilize the suction force on the outer periphery. There is a hole-shaped counterbore at the side end.

FIG. 8 is a cross-sectional view of the suction collet showing a case where the counterbore processing is performed on the suction surface side end of the suction hole and a case where the counterbore processing is not performed. As shown in FIG. 8, in the case of a suction collet in which the tip of the suction hole 12 is counterbored (see (a)), the hole-shaped portion 12 a
However, the speed of the airflow generated in the gap (about 0.05 mm) between the suction collet and the chip 15 during chip suction is reduced, and the collected dust contained in the airflow is reduced by the suction hole 1.
The dust falls from the airflow on the chip around the counterbore around 2 and the collected dust remains on the chip and adheres.

On the other hand, the improved collet for adsorption 1
With regard to 8, the hole-shaped portion is eliminated and the diameter of the suction hole 12 is made straight up to the tip portion that comes into contact with the upper surface of the chip 15 (see (b)). Without changing the speed of the air current generated in the gap (about 0.05 mm), the dust collected at the same time as sucking the chip 15 can be surely guided into the suction hole and evacuated and cleaned.

(Third Embodiment) FIGS. 9A and 9B show a semiconductor chip suction collet and a collet mounting part according to a third embodiment of the present invention. FIG. 9A is a sectional view of the suction collet. b) is a sectional view of the collet mounting part.

As shown in FIG.
Internally, the air pipes of the breaking hole 20 for vacuum breaking and the vacuum hole 22 for vacuum suction are formed independently of each other so as to communicate with the suction hole 12 for vacuum suction (see (a)). .
When the suction hole 12 and the destruction hole 20 are shared by one pipe as in the conventional case, dust adhering to the pipe during vacuum suction adheres again to the surface of the chip 15 during vacuum destruction. Resulting in. On the other hand, in the case of the improved suction collet 19 of the present invention, two systems for vacuum suction and vacuum breaking are branched and independently provided inside the collet, so that the dust once suctioned is again applied to the surface of the chip 15. Does not adhere to

In the structure shown in (b), the collet mounting part 21 has two separate air pipes for vacuum suction and vacuum break, which are independently held in order to make the structure simple in processing. This is formed as a separate block from the standard suction collet (for example, the suction collet 18 in FIG. 8B). The collet mounting part 21 is added to a standard suction collet, and integrated so that the vacuum breaking pipe communicates with the suction hole 12.

Such a collet mounting part 21 can be provided on the mounting plate 13 of FIGS. 2 and 7 described above.

As described above, according to the present invention, a plurality of suction holes 12 of the suction collet are arranged not at the center of the suction surface but at the periphery thereof, so that dust is not attracted to the center of the chip 15. No counterbore processing is applied to the periphery of the opening surface, so that dust collected at the center and sucked into the suction pipe is not left on the chip 15. Further, a chip suction pipe and a vacuum breaking pipe used for chip release are used for suction. Merge immediately before the collet, and remove the dust in the adsorption pipe
The structure does not return to the top.

Therefore, in the die bonding step, it is possible to provide a die bonder which does not cause dust to adhere to the chip 15 and can remove dust from the chip 15. Particularly, a glass used in an image processing device such as a CCD. It can also handle bonders. Furthermore, it is possible to use a suction collet that can also be used for a chip transfer machine.

As a result, the occurrence of product defects caused by semiconductor dust is reduced, the occurrence of equipment trouble caused by dust is reduced, the quality of special semiconductors such as CCDs is improved, and the yield is improved.

The suction collet in the above embodiment can also be applied to a semiconductor assembly apparatus having a mechanism for suctioning by vacuum when transporting or transferring chips and products / materials.

[0041]

As described above, according to the present invention, the semiconductor chip sucking collet used for bonding a chip to a package or the like, which sucks the chip, is provided at a peripheral portion other than the central portion of the suction surface. Since the pressure is reduced between the chip surface and the suction surface facing the chip through the plurality of suction holes, silicon dust and the like scattered on the wafer are not collected at the center of the chip surface.

Therefore, it is possible to reduce the occurrence of chip product defects caused by semiconductor dust, reduce the occurrence of equipment trouble on the device side caused by dust, improve the quality of special semiconductors such as CCDs, and increase the yield. Improve.

[Brief description of the drawings]

FIGS. 1A and 1B show a semiconductor chip suction collet according to a first embodiment of the present invention, wherein FIG. 1A is a bottom view, FIG. 1B is a side view, and FIG.

2A and 2B show a state in which the suction collet of FIG. 1 is mounted on a mounting plate, wherein FIG. 2A is a plan view and FIG. 2B is a front view.

FIG. 3 is an explanatory view showing another example of a suction hole provided in the suction collet of FIG. 1;

FIG. 4 is a chip plan view showing a chip suction surface of a CCD.

FIG. 5 is a sectional view showing a state in which the suction collet of FIG. 1 is positioned on a chip.

6A and 6B show a semiconductor chip suction collet according to a second embodiment of the present invention, wherein FIG. 6A is a bottom view, FIG. 6B is a side view, and FIG.

7A and 7B show a state in which the suction collet of FIG. 6 is mounted on a mounting plate, wherein FIG. 7A is a plan view and FIG.

FIG. 8 is a cross-sectional view of a suction collet showing a case where counterbore processing is performed on a suction hole side end of a suction hole and a case where counterbore processing is not performed.

FIG. 9 shows a collet for attaching a semiconductor chip and a collet mounting part according to a third embodiment of the present invention;
(A) is a cross-sectional view of a suction collet, and (b) is a cross-sectional view when a collet mounting part is mounted.

FIG. 10 is a schematic view of a conventional die bonder.

FIG. 11 is an explanatory view of a die bonding step accompanying movement of a chip in the die bonder of FIG. 10;

[Explanation of symbols]

10, 18, 19: Collet for adsorption, 10a, 18a:
Bottom (adsorption surface), 11: micro projection, 12: adsorption hole, 12
a: Hall-shaped part, 13: Mounting plate, 14: Counterbore, 1
5: chip, 16: light detection sensor unit, 17: contact unit, 2
0: breaking hole, 21: collet mounting part.

Claims (4)

[Claims] 1. A plurality of micro projections having an attraction surface facing a surface of a semiconductor chip to be attracted via a minute gap, and an attraction hole opened at the attraction surface, and forming the minute gap. Wherein the suction holes are provided at a plurality of peripheral portions other than the central portion of the suction surface, wherein the suction holes are provided at a plurality of locations on the periphery of the suction surface. . 2. The semiconductor chip suction device according to claim 1, wherein the suction hole has an edge portion opened to the suction surface in a state of a straight through hole having the same diameter without any step. Collet. 3. The collet for suctioning semiconductor chips according to claim 1, further comprising a vacuum breaking pipe for breaking vacuum suction caused by reduced pressure, in addition to said suction holes. 4. A semiconductor chip suction device according to claim 1, further comprising a collet mounting part made of a separate member, provided with a vacuum breaking pipe communicating with said suction hole for breaking vacuum suction caused by reduced pressure. For collet.