KR100311826B1 - Method for hermetic packaging in microsensors - Google Patents

Abstract

The present invention provides a microsensor capable of improving the sealability of the microsensor by forming a recessed portion in which Au-Si array (Alloy) can be gathered at the bonding peripheral edge for sealing the microsensor of the wafer device during fabrication of the microsensor. In particular, it relates to a sealing package method of a silicon wafer device in which a microsensor is installed on the upper side of the sensor periphery of the sensor to form an internal fixed point and an external fixed point, and the groove formed in the sealing bonding portion, and then composed of a certain thickness of silicon After forming an electrically conductive film pattern to which the internal fixed point and the external fixed point can be connected through the insulator through the insulator, the Cr / Au is deposited again via the secondary insulator and packaged by bonding sealing. do.

Description

Sealing package method of microsensor {METHOD FOR HERMETIC PACKAGING IN MICROSENSORS}

In the present invention, when manufacturing a micro-sensor, such as a micro-gyro, by forming a groove in which the Au-Si array (Alloy) can be gathered in the bonding peripheral edge for sealing the micro-sensor of the wafer device (Wafer Device), The present invention relates to a sealing package method of a microsensor capable of improving the sealing degree, and in particular, an internal fixing point and an external fixing point are formed around the upper side of the microsensor of the wafer device, and a low melting point sealing bonding part is formed in the middle thereof. The low melting point bonding portion is etched to form a recessed portion, and the micro sensor of the wafer device is sealed through Au-silicon low melting point bonding of the wafer cap placed thereon, thereby bonding the wafer device and the wafer peripheral edge of the wafer cap for sealing the microsensor. Grooves are provided for gathering Au-si arrays. Au-Si by an array may increase the sealing degree of the micro-sensor is gailcheung, to a method of sealing paekaeji microsensors allow easy and the micro-sensors, can be easily sealed package.

In a conventionally known sealing package method of a microsensor, as shown in FIG. 1, the wafer is formed by molding the glass 30 on the upper side of the silicon device 10 on which the microsensor 20 is mounted. The cap 40 is bonded to each other. At this time, after the via hole 50 is formed in the glass 30, a metal film 60 such as aluminum is formed inside the via hole 50 by sputtering to form a micro sensor. To seal the package.

However, during bonding of the wafer cap 40 made of the glass 30 to bond the wafer cap 40 made of the glass 30 to the silicon device 10 to perform a sealing package. There is a disadvantage in that the degree of vacuum of the microsensor decreases due to the release of ions, and the yield decreases due to warping caused by bonding between glass and silicon, and a difference in thermal expansion coefficient between the wafer cap and the wafer device occurs. Due to the occurrence of stress, it is difficult to properly package an inertial sensor such as a micro gyroscope which is extremely sensitive to the surrounding atmosphere, and there are many problems.

SUMMARY OF THE INVENTION The present invention has been made to solve various problems of the related art as described above, and an object thereof is to provide a recessed portion in which an Au-Si array can be gathered at a peripheral edge of a wafer cap and a wafer cap for sealing a microsensor. By the Au-Si array gathered in the groove part, the sealing degree of the microsensor, which is an inertial sensor sensitive to the surrounding atmosphere, can be further increased, and the sealing package method of the microsensor can be easily and easily sealed packaged. It is.

1 is a view for explaining a sealing package method of a conventional microsensor.

2A to 2F are schematic configuration diagrams for explaining a sealing package process of a microsensor according to the formation of a wafer device and a wafer cap according to the present invention.

Figure 3 is a front cross-sectional structure of the bonded state of the wafer device and the wafer cap in which the recess is formed in the sealing bonding portion of the mitro sensor according to the present invention the package is completed.

Explanation of symbols on the main parts of the drawings

110 ... Silicone 120 ... Insulator

130 ... micro sensor 140 ... wafer device

150 ... internal anchor point 160 ... external anchor point

170 ... Seal bonding part 210 ... wafer cap

220,220 '... insulator 230 ... conductor pattern

240 ... Cr / Au deposited layer 250 ... wire bonding

300 Groove

As a technical configuration for achieving the above object, the present invention is to form an internal fixed point and an external fixed point around the sensor periphery of a silicon wafer device in which a microsensor is installed on the upper side of a silicon with an insulator interposed therebetween. A bonding part forming step of forming a low melting point sealing bonding part therebetween;

A groove portion forming step of removing a lower side of the low melting point sealing bonding portion by etching to form a groove portion;

An insulator removal step of removing the insulators at portions other than the outer and inner fixing points of the wafer device and the low melting point sealing bonding portion by etching;

A conductive film pattern forming step of depositing an insulator on an upper side of a wafer cap made of silicon having a predetermined thickness, and forming a conductive film pattern to which an internal fixed point and an external fixed point can be connected on the upper side;

Depositing and patterning a second insulator on the conductive layer pattern to protect the conductive layer, and depositing and patterning Cr / Au on the upper side of the insulator pattern;

An etching step of etching the outside of the external fixing point connection portion of the wafer cap to enable wire bonding from the external fixing point of the wafer device;

And sealing the microsensor of the wafer device by low melting point bonding the wafer cap to the wafer device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 (A) to 2 (F) is a schematic configuration diagram for explaining a sealing package process of a microsensor according to the formation of a wafer device and a wafer cap according to the present invention, Figure 3 is a mitro sensor according to the present invention Of the wafer device and the wafer cap in which the recessed portion is formed in the sealing bonding portion of the sealing package, and the micro sensor is provided through an insulator 120 formed of an oxide film on the silicon 110 having a thickness of about 500 μm. At the peripheral edge of the sensor of the silicon wafer device 140 where the 130 is installed upward, internal fixing points 150 and external fixing points 160 are formed at regular intervals (A in FIG. 2).

In this case, a low melting point sealing bonding part 170 may be formed between the inner fixing point 150 and the outer fixing point 160 so that the micro sensor 130 may be sealed during bonding with the wafer cap 210. The lower side of the melting point sealing bonding portion is removed by etching to form the groove portion 300 (groove).

The wafer device 140 fabricated as described above has the insulator 120 at the portion except for the external fixation point 160 and the internal fixation point 150 and the low melting point sealing bonding portion 170, as shown in FIG. Is removed by an etching process to complete the wafer device 140.

Subsequently, an insulator 220 is deposited on the wafer cap 210 formed of silicon having a predetermined thickness so as to be bonded to the wafer device 140, and an inner fixing point 150 of the wafer device 140 is deposited thereon. ) And the external fixing point 160 may be formed to connect the conductive film pattern 230 (C of FIG. 2).

In addition, the secondary insulator 220 ′ may be deposited on the conductive layer pattern 230 to protect the conductive layer pattern 230 (FIG. 2D), and the secondary insulator ( On the upper side of the pattern 220 ', as shown in E of FIG. 2, the Cr / Au deposition layer 240 is patterned to bond the wafer device 140 to the silicon-Au-Cr- at the fixed point 150. The conductive film is connected to the conductive film, and the conductive film wiring is connected to the conductive film-Cr-Au-silicon to the external fixing point 160.

Meanwhile, as shown in FIG. 2F, the outside of the connection point of the external fixing point 160 of the wafer cap 210 is etched to enable the wire bonding 250 from the external fixing point 160 of the wafer device 140. In this case, the etching operation is performed by a photo-resist so as not to affect Cr / Au at all.

When the fabrication of the wafer device 140 and the wafer cap 210 is completed as described above, as shown in FIG. 3, the wafer cap 210 is heated and pressurized with the wafer device 140 at about 400 ° C. to thereby provide low melting point bonding. By sealing the microsensor 130 of the wafer device 140, in this case, Au is conductive, so it is possible to simultaneously perform two roles of bonding and conduction.

At this time, Au melted by heat and pressure during low melting point bonding at the corners of the recess 300 formed in the sealing bonding unit 170 when the wafer device 140 and the wafer cap 210 are low melting point bonding as described above. Si arrays are gathered to improve the sealing degree of the inertial sensor 130 installed in the wafer device 140.

As described above, according to the sealing package method of the microsensor according to the present invention, a groove for collecting Au-Si arrays is provided at the bonding peripheral edge of the wafer device and the wafer cap for sealing the microsensor, and the Au- collected in the grooves. The Si array makes it possible to further increase the sealing degree of the micro sensor, which is an inertial sensor sensitive to the ambient atmosphere, and has an excellent effect of easily and easily sealing the micro sensor.

Claims (4)

In the sealed package method of the microsensor, A bonding part forming step of forming an internal fixing point and an external fixing point around the sensor periphery of the silicon wafer device in which the micro sensor is installed on the upper side of the silicon with an insulator interposed therebetween, and forming a low melting point sealing bonding part therebetween; A groove portion forming step of removing a lower side of the low melting point sealing bonding portion by etching to form a groove portion; An insulator removal step of removing the insulators at portions other than the outer and inner fixing points of the wafer device and the low melting point sealing bonding portion by etching; A conductive film pattern forming step of depositing an insulator on an upper side of a wafer cap made of silicon having a predetermined thickness, and forming a conductive film pattern to which an internal fixed point and an external fixed point can be connected on the upper side; Depositing and patterning a second insulator on the conductive layer pattern to protect the conductive layer, and depositing and patterning Cr / Au on the upper side of the insulator pattern; An etching step of etching the outside of the external fixing point connection portion of the wafer cap to enable wire bonding from the external fixing point of the wafer device; Sealing the microsensor of the wafer device by low melting point bonding the wafer cap to the wafer device. The method of claim 1, wherein the etching of the outer fixing point connection portion of the wafer cap is performed by a photoresist having no influence on Cr / Au to enable wire bonding from the external fixing point of the wafer device. Sealing package method of microsensor. The sealing of the microsensor according to claim 1, wherein the Cr / Au deposition layer of the wafer cap is patterned to be connected to the silicon-Au-Cr-conducting film at an internal fixed point when bonding the wafer device. Package way. The Cr / Au deposition layer of the wafer cap is patterned so that, when bonding the wafer device, the conductive film wiring is connected to the conductive film-Cr-Au-silicon to an external fixed point. Sealing package method of microsensor.