JPS63261849A - Micro vacuum chuck - Google Patents

Abstract

PURPOSE:To enable an operator to move a chip while observing it for positioning the chip with improved accuracy, by constructing a vacuum chuck such that the chip sucked by a suction port can be observed through a specific member. CONSTITUTION:A flat-plate-type member 1 of a material transparent to visible and infrared radiation, for example of sapphire is provided with a suction port 2 for sucking a chip 5; an exhaust port 3 formed outside a region occupied by a sucked chip and connected to an external discharge system; and a vacuum passage 4 connecting between the suction and discharge ports 3. The discharge port 3 is connected to a discharge tube 6 to draw a vacuum. A vacuum chuck thus constructed allows an operator to observe a chip being sucked by the suction port, through the member 1. Accordingly, the operator can position the chip at a predetermined position with desirable positional accuracy.

Description

[Detailed Description of the Invention] [Summary] A micro vacuum chuck made of a material transparent to visible light and infrared light and capable of suctioning and moving a microchip is set up, and the chip is held in a predetermined position while observing the chip. This improves the accuracy of two-position alignment.

[Industrial application field]

The present invention relates to a micro vacuum chuck that can suck and move microchips.

Vacuum chucks are used in chip moving devices used for chip bonding or wire bonding of semiconductor chips and the like.

[Conventional technology]

Vacuum chucks that suck chips through metal pipes are mainly used in chip transfer devices.
As the chip size decreases, it becomes necessary to decrease the diameter of the pipe.

However, it is difficult to reduce the diameter of the pipe to 200 μm or less in terms of processing accuracy, and there is a limit to the size of the chip that can be moved.

FIG. 5 is a sectional view showing the relationship between a conventional vacuum chuck and a chip.

In the figure, a vacuum chuck 51 made of a metal pipe, etc.
The chip 52 is moved by vacuum suction and placed in a predetermined position.

[Problem that the invention seeks to solve]

In the conventional example, the outer diameter of the vacuum chuck 51 must be smaller than the dimension B of the chip 52. For this reason, chips smaller in size than 8 could not be moved.

Also, since there is a vacuum chuck 51 on the chip 52.

It was not possible to directly pick up the chip 51 from directly above using a microscope or the like. Therefore, alignment during bonding was difficult.

[Means for solving problems]

A solution to the above problem includes a member made of a material transparent to visible light and infrared light.

It has a suction hole that suctions the chip, an exhaust hole that is provided outside the area occupied by the sucked chip and is connected to an external exhaust system, and a vacuum path that connects the suction hole and the exhaust hole. by means of a micro vacuum chuck that allows the thousand knobs to be observed through the member when the chip is sucked into the suction hole, or by two flat plates made of a material transparent to visible light and infrared light; a cylindrical member that is airtightly sandwiched between the two flat plates and has an exhaust hole;
This is achieved by a micro vacuum chuck characterized by having suction holes opened in one flat plate.

[Effect]

By using a material transparent to visible light and infrared light for the construction of the vacuum chuck, the present invention eliminates the above-mentioned restriction that the outer diameter of the chuck must be made smaller as chips become smaller. , which allows the chip to be observed directly from above using a microscope or the like.

〔Example〕

FIGS. 1(1) and 1(2) are a sectional view and a plan view of a vacuum chuck illustrating a first embodiment.

In the figure, the vacuum chuck has a suction hole 2 for suctioning a chip 5 in a flat member 1 made of a material 9 transparent to visible light and infrared light, for example, sapphire, and a hole 2 for sucking the chip 5. An exhaust hole 3 provided outside the area and connected to an external exhaust system (not shown), and a vacuum path 4 connecting the suction hole 2 and the exhaust hole 3 are formed.

The member 1 uses a disk with a thickness of 800 μm, and the suction holes 2 have 50
The vacuum path 4 is machined to about 400 μmφ. Further, the outer diameter of one member 1 is made larger than the size of the tip to be aspirated.

The exhaust hole 3 is connected to an exhaust pipe 6 to perform evacuation.

The vacuum chuck having the above configuration allows the chip to be observed through the member 1 when the chip is sucked into the suction hole.

Furthermore, as mentioned above, since the thickness of the chuck can be reduced to about 1 mm, the working distance of the microscope can be reduced. Therefore, it can be observed at a high magnification of 20x or more,
Chip positioning accuracy can be improved.

FIGS. 2(1) to 2(3) are a cross-sectional view, a plan view, and a cross-sectional view of a groove of a vacuum chuck explaining a second embodiment.

The difference from FIG. 1 is that the flat member 1 is constructed by overlapping a member IA in which a suction hole 2 is formed and a member IB in which a vacuum path 4 is formed.

The member IA is a disk with a thickness of 100 μm, and the suction holes 2 are 5
Processed to 0 μmφ.

As member IB, a disk having a thickness of about 400 to 800 μm is used.

The vacuum path 4 is provided at a depth of 200 to 500 μm on the surface of member IB.
(Fig. 2 (3)).

An exhaust hole 3 at one end of the groove is connected to an exhaust pipe 6.

Perform vacuuming. Further, the other end of the groove is sealed by a sealing cover 7.

In the case of FIG. 1, it is difficult to drill the vacuum path 4 in the three members 1, but this case has the advantage that the vacuum path 4 can be easily formed by groove machining.

FIG. 3 is a sectional view and a plan view of a vacuum chuck explaining a third embodiment.

The difference from FIG. 2 is that the member IA in which the suction hole 2 is formed,
A metal cylindrical member 8 having an exhaust hole 3 is sandwiched between flat unprocessed members 18 in an airtight manner.

In this case, the thickness of the vacuum chuck can only be reduced to about 5 mm, but it has the advantage of being able to provide a large suction force.

Furthermore, if one member IB is configured to be slightly inclined with respect to member IA, reflected light can be prevented during microscopic mtk observation, making observation easier.

Although only one suction hole is provided in the embodiments shown in FIGS. 1 to 3 above, a plurality of suction holes may be provided depending on the size of the chip.

FIG. 4 (11 and 21 are cross-sectional views of a semiconductor chip and a substrate on which the chip is mounted and bonded) showing an application example of the present invention.

Figure 4 (1) shows the PIN (1' type-Intrin
sic-N type) structure photodiode (PI
N'PD) is a cross-sectional view of the chip.

The chip 5 has the following structure.

That is, InGaAs is placed in the light receiving area of the InP substrate 5A.
A light absorbing layer 5B is formed, and this layer is separated from the surroundings by a groove '5C formed around the light receiving area.

On the chip surface, there is a p-side electrode P in the light receiving area.

Further, an n-side electrode N is formed around it with a groove 43 in between.

Chip size is 200μm square or less, thickness is 40-60μm
It is.

InP has a wavelength of 1.8μ when the thickness is about 100μm or less.
It is transparent to infrared light of about 500 m, and electrodes P and N can be observed even if the chip is suctioned from the back side of the chip using a vacuum chuck, and alignment will not be affected.

FIG. 4(2) is a diagram in which the chip 5 is mounted on a ceramic substrate 41. The electrodes P and N of the chip 5 are aligned and placed on the wiring layer 42 formed on the substrate 41, and fixed by bonding. .

PIN PD is APD (Avalanche Photo
Since it does not involve multiplication like diodes), the response speed is fast but the sensitivity is low, so instead of a ceramic substrate,
Sometimes it is mounted on a GaAs substrate with an amplifier built into it.

〔Effect of the invention〕

According to the present invention as described in detail above.

It is possible to suction and move microchips of 200 μm or less.

In addition, 1. The microchip can be observed both from directly above and from an angle, and the chip can be placed in a predetermined position with a good positional accuracy of ±4 μm or less.

[Brief explanation of drawings]

FIGS. 1(1) and 1(2) are a sectional view and a plan view of a vacuum chuck explaining a first embodiment. Fig. 2 (11 to (3)) are a cross-sectional view and a plan view of a vacuum chip explaining a second embodiment. Fig. 4 (1) and (2) are a semiconductor chip and a chip showing an application example of the present invention. A cross-sectional view of a substrate on which is mounted and bonded. Figure 5 is a cross-sectional view showing the relationship between a conventional vacuum chuck and a chip. In the figure. 1 is a flat member made of sapphire. IA is a suction hole 2 formed. 1B is a member that forms the vacuum path 4. 2 is a suction hole. 3 is an exhaust hole. 4 is a vacuum path. 5 is a chip. 6 is an exhaust pipe. 7 is a sealing cover. 8 has an exhaust hole 3 Cross-sectional view and plan view of the first actual travel row of metal cylindrical members Fig. 1 Figure q,! Figure 8, item 1 parts Figure 3

Claims (5)

[Claims] (1) A suction hole that suctions the chip, an exhaust hole that is provided outside the area occupied by the sucked chip and connects to an external exhaust system, and a vacuum path that connects the suction hole and the exhaust hole. and a member made of a material transparent to visible light and infrared light, and the chip can be observed through the member when the chip is sucked into the suction hole. Chuck. (2) The micro vacuum chuck according to claim 1, wherein the member is composed of one or two flat plates. (3) two flat plates made of a material transparent to visible light and infrared light; sandwiched between the two flat plates while maintaining airtightness;
A micro vacuum chuck characterized in that it has a cylindrical member having an exhaust hole, and a suction hole is opened in one flat plate. (4) The micro vacuum chuck according to claim 3, wherein the two flat plates are arranged substantially parallel to each other. (5) The micro vacuum chuck according to claim 3, wherein the two flat plates are arranged at a slight angle to each other.