JP5034201B2 - Manufacturing method of sensor chip - Google Patents

Description

  The present invention relates to a sensor chip, and more particularly, to a sensor chip provided with a protective material on the active surface side of a sensor body such as an image sensor such as a CCD or CMOS, or an acceleration sensor, and a method for easily manufacturing the sensor chip.

For example, an image sensor such as a CCD or CMOS generally has an active surface in which a color filter layer and a condensing lens are arranged on an array of a plurality of fine light receiving portions (pixels), and an area outside the active surface. In addition, a plurality of terminals for sending signals to the outside are provided. In a sensor chip having such an image sensor, a transparent protective material is provided to protect the active surface of the image sensor. In order to allow a desired gap to be present between the protective material and the active surface, the periphery of the active surface is molded with a resin, or a projection frame made of an insulating resin is interposed. (Patent Documents 1 and 2)
JP-A-3-155671 JP-A-6-204442

However, if the pressure when fixing the protective material to the image sensor is large, the resin member such as the projection frame may spread and the active surface and terminals may be covered. If the pressure at the time of adhering to the sensor is too small, adhesion failure occurs, and there is a problem that moisture penetrates into the gap between the active surface and the protective material in a subsequent process or the like.
In addition, in a conventional resin member such as a projection frame, for example, when a protective material is fixed under reduced pressure, the pressure in the gap between the active surface and the protective material becomes smaller than the external pressure, and acts on the resin member from the outside. There is also a problem that deformation or the like is caused by the applied pressure, and there is a possibility that moisture, dust, or the like may enter the gap portion together with the gas.

Further, the conventional sensor chip has a protective material larger than that of the sensor body, which hinders downsizing of the sensor chip itself and further downsizing of electronic devices incorporating the sensor chip.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a sensor chip that is small and excellent in durability, and a manufacturing method for easily manufacturing such a sensor chip. .

In order to achieve such an object, a method for manufacturing a sensor chip according to the present invention includes an active surface, a step of manufacturing a sensor body having a plurality of terminals in an outer region of the active surface, and a one surface. A protective material having a multi-sided corridor-shaped convex portion integrally aligned with the sensor body imposition position and a lattice-shaped clearance concave portion outside the convex portion for each imposition is prepared. A step of disposing the protective material on the sensor main body by fixing the convex portion between the active surface of the sensor main body and the terminal forming region, and for each imposition of the protective material. A step of removing an unnecessary portion of the protective material in which the clearance concave portion between the convex portions exists, a step of dicing the sensor body with multiple faces to obtain individual sensor chips, Has, the clearance recess, Ri protective material between adjacent said projections Do an arch shape, and than the thickness of the protective material of the thickness of the protective material is surrounded by the convex regions in the deepest portion was such as to form into a smaller so that configuration.

As another aspect of the present invention, in the step of producing the protective material, one surface of the protective material is ground and / or etched into a grid pattern to form a concave portion, and then the concave portion is etched and flattened. The protective material between the concave portions is ground to form the clearance concave portions and the convex portions.
As another aspect of the present invention, in the step of producing the protective material, the protective material is melted, injected into a mold, and solidified to form the protective material.
As another aspect of the present invention, the mold is configured to use a carbon mold.

In such a sensor chip of the present invention, since the protective material is disposed on the sensor body through the convex portion that is integrally provided, the mechanical strength of the protective material is high, and the gap between the active surface and the protective material is low. Even if there is a difference between pressure and external pressure, the active surface can be reliably sealed and the durability is extremely high, and the area of the protective material is less than the area of the sensor body. It is the same size as the sensor body, and the sensor chip can be significantly downsized compared to the conventional size.
In the sensor chip manufacturing method of the present invention, when the protective material is disposed on the sensor main body via the convex portion, the mechanical portion of the convex portion is not affected even if the pressure is increased in order to obtain good adhesion. Since the strength is high and there is almost no deformation, it is possible to prevent the active surface and terminals from being adversely affected, and at the same time, it is easy to make the gap between the active surface of the sensor body and the protective material uniform and desired. After the protective material with the convex part of the height is provided on the sensor body, it is possible to polish and remove only unnecessary parts of the protective material to reduce the area without damaging the sensor body. Accordingly, it is possible to manufacture a sensor chip with high durability, small size, and high quality. In addition, in the case of manufacturing with multiple facets, by providing a clearance concave portion in an unnecessary part of the protective material, it becomes easier to polish and remove only the unnecessary part of the protective material.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Sensor chip]
FIG. 1 is a schematic sectional view showing an embodiment of a sensor chip of the present invention. In FIG. 1, a sensor chip 1 according to the present invention includes an active surface 2A, a sensor body 2 having a plurality of terminals 3 arranged on the outer region of the active surface 2A via wirings 3a, and a corridor-shaped convex portion. The protective material 4 is integrally provided on one surface, and the protective material 4 is obtained by fixing the convex portion 5 to the region between the active surface 2A and the terminal 3 using an adhesive. The sensor body 2 is disposed. This protective material 4 is opposed to the active surface 2A of the sensor body 2 through a desired gap 6, and seals the gap 6 together with the convex portion 5 to protect the active surface 2A.

  FIG. 2 is a view for explaining the corridor-shaped convex portion 5 integrally provided on one surface of the protective material 4. In the present invention, the convex portion 5 may have an independent corridor shape as shown by hatching in FIG. 2 (A), and as shown by hatching in FIG. 2 (B). Alternatively, it may have a corridor shape composed of a plurality of line-shaped convex portions 5a and convex portions 5b orthogonal to the lattice shape. The above-mentioned hatched corridor shape may be either a square or a rectangle, and may be a rhombus, a parallelogram, a circle, an ellipse or the like if necessary. The “integral” means that the protective material 4 and the convex portion 5 are made of the same material, and the convex portion 5 is formed simultaneously with the formation of the protective material 4.

  FIG. 3 is a schematic cross-sectional view showing another embodiment of the sensor chip of the present invention. In FIG. 3, the sensor chip 11 of the present invention includes an active surface 12A, a plurality of wirings 13a drawn to the outer area of the active surface 12A, and a plurality of wirings 13a connected to the wirings 13a via front and back conductive vias 17. The sensor main body 12 having the terminal 13 on the back surface (the surface opposite to the active surface 12A) and the protective material 14 having the corridor-shaped convex portion 15 integrally on one surface are provided. The convex portion 15 is disposed on the sensor main body 12 by being fixed to the region outside the active surface 12A via an adhesive. This protective material 14 is opposed to the active surface 12A of the sensor main body 12 with a desired gap 16 therebetween, and seals the gap 16 together with the convex portion 15 to protect the active surface 12A. In addition, the corridor shape of the convex part 15 in this sensor chip 11 may be either of FIG. 2 (A) and FIG. 2 (B) similarly to the convex part 5 in the sensor chip 1 described above.

Further, as shown in FIG. 4, as shown in FIG. 4, the sensor chip 11 having the terminals 13 on the back surface through the front and back conductive vias 17 as shown in FIG. 3 is connected to the wiring 13 a and the front and back conductive vias 17. And the terminal 13 may be located below the convex portion 15. With such a structure, the sensor chip 11 can be further reduced in size.
The sensor bodies 2 and 12 constituting the sensor chips 1 and 11 of the present invention may be image sensors such as CCD and CMOS, various MEMS (Micro Electromechanical System) sensors such as an acceleration sensor, a pressure sensor, and a gyro sensor. . In addition, the active surfaces 2A and 12A of the sensor bodies 2 and 12 mean regions that exhibit a desired detection function of the sensor, such as regions where light receiving elements that perform photoelectric conversion are arranged to form a plurality of pixels. .
The plurality of terminals 3 and 13 included in the sensor bodies 2 and 12 are terminals for sending signals to the outside. In the sensor chip 11, these terminals 13 are connected to the back surface of the sensor body 12 through front and back conductive vias 17. The material of the terminals 3 and 13 and the wirings 3a and 13a can be a conductive material such as aluminum, copper, silver, gold, or nickel, and may have a laminated structure of a plurality of types of conductive materials. The material of the front and back conductive vias 17 can be a conductive material such as copper, silver, gold, or tin, or a conductive paste containing these conductive materials.

  The protective members 4 and 14 constituting the sensor chips 1 and 11 of the present invention have corridor-shaped convex portions 5 and 16 so as to form gaps 6 and 16 between the active surfaces 2A and 12A of the sensor bodies 2 and 12, respectively. 15 is fixed to the sensor bodies 2 and 12. For the protective materials 4 and 14, for example, materials such as glass, polyimide, polycarbonate, quartz, arton, cellulose triacetate, cycloolefin polymer, and polyester can be used, and a material having an infrared absorption function is used. It may be one that also serves as an infrared cut filter, and further has at least one of an antireflection film and a low-pass filter. The size of the protective members 4 and 14 (the size of the surface facing the sensor main bodies 2 and 12) is less than the area of the sensor main bodies 2 and 12. In the example shown in FIG. 1, the protective material 4 is present inside the region where the terminal 3 of the sensor body 2 is formed, and the terminal 3 is exposed.

The thickness of the protective materials 4 and 14 (the thickness of the portion where the convex portions 5 and 15 do not exist) can be set in the range of 0.2 to 0.5 mm, for example, in consideration of the material, light transmittance, and the like. . The thickness of the gaps 6 and 16 existing between the protective members 4 and 14 and the active surfaces 2A and 12A of the sensor bodies 2 and 12 can be set in the range of 2 to 100 μm, for example.
Corridor-shaped convex portions 5 and 15 provided integrally with the protective members 4 and 14 are outside the active surfaces 2A and 12A of the sensor main bodies 2 and 12 and inside the terminals 3 and 13. It has a size and shape that can be fixed. Note that, as in the example shown in FIG. 4, the formation region of the terminal 13 of the sensor body 12 and the position of the convex portion 15 of the protective material 14 may be substantially coincident with each other. The position may be present inside the position of the convex portion 15 of the protective material 14.
The height and width of the convex portions 5 and 15 can be appropriately set in consideration of the thickness of the gaps 6 and 16, and the like. For example, the height is 2 to 100 μm and the width is 50 to 500 μm. Can be set by range.

  In the sensor chips 1 and 11 of the present invention as described above, the protective members 4 and 14 are disposed on the sensor body via the convex portions 5 and 15 that are integrally provided, and the protection including the convex portions 5 and 15 is provided. The mechanical strength of the materials 4 and 14 is high, and the gaps 6 and 16 are surely sealed even if a difference between the pressure in the gaps 6 and 16 and the external pressure between the active surfaces 2A and 12A and the protective materials 4 and 14 occurs. can do. In addition, since the area of the protective materials 4 and 14 is equal to or smaller than the area of the sensor bodies 2 and 12, the size of the sensor bodies 2 and 12 becomes the size of the sensor chips 1 and 11 as they are. Can be miniaturized.

The sensor chip of the present invention can be connected to and mounted on another substrate or the like using the terminals 3 and 13 or the back surface (surface where the active surface 12A does not exist) side of the front and back conductive vias 17. For example, the sensor chip 1 shown in FIG. 1 can be mounted on the substrate 21 having the opening 22 and the wiring 23 via the bumps 24 in the form shown in FIG. In the illustrated example, after the sensor chip 1 is mounted, the insulating material 25 is poured into the opening 22 of the substrate 21 and sealed, but at this time, the active surface 2A ( The insulating material 25 is prevented from flowing into the gap 6).
The sensor chip described above is an example, and the present invention is not limited to these embodiments.

[Method for manufacturing sensor chip]
Next, a method for manufacturing the sensor chip of the present invention will be described.
FIG. 6 is a process diagram showing an embodiment of the sensor chip manufacturing method of the present invention, using the sensor chip 1 shown in FIG. 1 as an example.
First, the sensor body 2 is manufactured by applying multiple faces to the silicon wafer 31 (FIG. 6A). The sensor body 2 can be manufactured using a conventionally known method such as a MEMS (Micro Electromechanical System) method, a photodiode manufacturing method (semiconductor process), or the like. The produced sensor body 2 has an active surface 2A on the surface, and has a plurality of terminals 3 in the region outside the active surface 2A via wirings 3a.

  On the other hand, the concave portion 4a is formed on one surface of the base material 4 'for forming the protective material 4, and the protective material 4 integrally having the corridor-shaped convex portion 5 is formed (FIG. 6B). As the base material 4 ', for example, a material such as glass, polyimide, or polycarbonate can be used, or a material having an infrared absorption function may be used. For example, the concave portion 4a is formed on the base material 4 'by forming a resist pattern for forming the convex portion 5 on one surface of the base material 4', and the base material 4 'through the resist pattern. On the other hand, it can be performed by grinding such as sandblasting, wet etching, or dry etching. Also, grinding and etching may be combined. For example, the convex portion 5 is first formed by grinding, and then the surface of the concave portion 4a (including the surface facing the active surface 2A) is etched and flattened. The thickness of the protective material 4 can be made uniform.

  Moreover, you may form the protective material 4 which has the convex part 5 integrally by fuse | melting a protective material raw material, injecting in a metal mold | die, and solidifying. The protective material material can use inorganic materials such as glass as described above, organic materials such as polyimide, polycarbonate, cellulose triacetate, cycloolefin polymer, polyester, etc., and the melting temperature depends on the material of the protective material material Can be set as appropriate. Further, the mold to be used is not particularly limited, but when the protective material is an inorganic material such as glass, the thermal expansion coefficient of the material and the mold is close to each other, and the convex portion 5 having a fine shape without storing strain stress therein. In consideration of the point that can be formed, it is preferable to use a carbon mold.

  Next, the protective material 4 is disposed on the sensor body 2 by fixing the convex portion 5 to the sensor body 2 of each imposition on the outside of the active surface 2A and inside the terminal 3 (see FIG. 6 (C)). The protective material 4 is disposed on the sensor main body 2 via the convex portion 5 by applying an adhesive to the tip of the convex portion 5, contacting the sensor main body 2, and curing by ultraviolet irradiation or the like. it can. In the step of disposing the protective material 4, since the convex portion 5 is provided integrally with the protective material 4, even if the pressure is increased to obtain good adhesion, the convex portion 5 is deformed. There are no adverse effects caused by fluctuations in the gap 6 or by covering the active surface 2A and the terminals 3.

Next, unnecessary portions of the protective material 4 are removed by grinding, and the protective material 4 is fixed to each sensor body 2 (FIG. 6D). The protective material 4 can be ground by, for example, using a diamond cutter and stopping grinding (dimension cut) just before the diamond cutter contacts the silicon wafer 31. In the illustrated example, the protective material 4 is polished so that the terminals 3 of each sensor body 2 are exposed. In the present invention, by appropriately controlling the thickness of the substrate 4 ′ before the formation of the protrusions 5 and the degree of polishing and etching during the formation of the protrusions, or by the mold design, the protrusions having a desired height. 5 can be formed, so that after the protective material 4 is disposed on the sensor body, only unnecessary portions of the protective material 4 are ground and removed without damaging the sensor body 2 to form the protective material 4 with a small area. it can.
Next, each sensor chip 1 can be obtained by dicing the silicon wafer 31 (FIG. 6E).

FIG. 7 is a process diagram showing another embodiment of the sensor chip manufacturing method of the present invention, using the sensor chip 11 shown in FIG. 3 as an example.
First, the sensor main body 12 is manufactured by applying multiple faces to the silicon wafer 41 (FIG. 7A). The sensor body 12 can be produced in the same manner as the sensor body 2 described above, and the produced sensor body 12 has an active surface 12A on the surface and a plurality of drawers reaching the region outside the active surface 12A. The wiring 13a is provided.
Next, a fine through hole 18 is formed at the tip portion of the wiring 13 a of each sensor body 12, and a conductive material is disposed in the fine through hole 18 to form a front / back conductive via 17, and a terminal connected to each front / back conductive via 17. 13 is formed on the back surface (opposite surface of the active surface 12A) (FIG. 7B).

  The fine through-hole 18 is formed, for example, by forming a mask pattern on the back surface (opposite surface of the active surface 12A) of the silicon wafer 41, and for the exposed silicon wafer 41, ICP- which is a dry etching method using plasma. It can be formed by RIE (Inductively Coupled Plasma-Reactive Ion Etching) method. Further, the fine through holes 18 can be formed by a sand blast method, a wet etching method, or a femtosecond laser method. The opening diameter of the fine through hole 18 can be set in the range of 30 to 80 μm, for example.

The conductive material is disposed in the fine through hole 18 by, for example, forming a base conductive thin film in the fine through hole 18 by a plasma CVD method or the like and then depositing a metal by electrolytic filling plating. Can do. Alternatively, the front and back conductive vias 17 can be formed by filling a conductive paste into the fine through holes 18.
When the sensor chip 11 shown in FIG. 4 is manufactured, the length of the wiring 13a is shortened and the formation position of the fine through hole 18 is set closer to the active surface 12A than in the above example.

On the other hand, the concave portion 14a is formed on one surface of the base material 14 'for forming the protective material 14, or the molten protective material raw material is injected into a mold and solidified to thereby form a corrugated convex portion 15. Is formed integrally (FIG. 7C). The method of forming such a protective material 14 and the material used can be the same as those of the protective material 4 described above.
Next, the protective material 14 is disposed on the sensor body 12 by fixing the projection 15 to the sensor body 12 of each imposition on the outside of the active surface 12A and inside the terminal 13 (see FIG. 7 (D)). The protective material 14 can be disposed on the sensor main body 12 via the convex portion 15 by applying an adhesive to the tip portion of the convex portion 15, contacting the sensor main body 12, and curing the adhesive. In the step of disposing the protective material 14, since the convex portion 15 is provided integrally with the protective material 14, even if the pressure is increased in order to obtain good adhesion, the convex portion 15 is deformed. There is no adverse effect caused by the fluctuation of the gap 16 and the covering of the active surface 12A and the terminal 13.
Next, the protective material 14 and the silicon wafer 41 are diced to obtain individual sensor chips 11 (FIG. 7E).

FIG. 8 is a process diagram showing another embodiment of the sensor chip manufacturing method of the present invention, taking the sensor chip 1 shown in FIG. 1 as an example.
The protective material 4 used in this embodiment is basically the same as the protective material 4 of the above-described embodiment, and has a multi-sided corridor-shaped convex portion 5 integrally. It is assumed that a clearance concave portion 4b is provided at an unnecessary portion (FIG. 8A). In other words, the protective material 4 has a concave portion 4a on the inner side of the convex portion 5, and has a concave portion for clearance 4b in a lattice shape on the outer side.
Next, in the same manner as in the embodiment described above, the sensor main body 2 is manufactured by multi-sided attachment to the silicon wafer 31, and the area of the sensor main body 2 of each imposition is outside the active surface 2 </ b> A and inside the terminal 3. The protective material 4 is disposed on the sensor body 2 by fixing the convex portion 5 to the sensor body 2 (FIG. 8B).

Next, unnecessary portions of the protective material 4 are removed by grinding, and the protective material 4 is fixed to each sensor body 2 (FIG. 8C). The grinding of the protective material 4 can be performed in the same manner as in the above-described embodiment. In this embodiment, the clearance 4b is present above the silicon wafer 31 and the terminals 3, so that the protective material 4 is ground. And the distance is large. For this reason, control for stopping grinding (dimension cut) just before the diamond cutter comes into contact becomes easier.
Next, each sensor chip 1 can be obtained by dicing the silicon wafer 31 (FIG. 8D).
Of course, in the manufacture of the sensor chip 11 shown in FIGS. 3 and 4, a protective material having a clearance recess can be used.

Here, an example of manufacturing the protective material 4 provided with the clearance recess 4b will be described.
First, the concave portion 4a is formed on one surface of the base material 4 ′ for forming the protective material 4 (FIG. 9A). The recess 4a can be formed by grinding such as sandblasting, wet etching, dry etching, or a combination of grinding and etching, as in the above-described embodiment. Next, unnecessary portions of the protective material 4 are ground with a grinding blade to form a clearance recess 4b and a protrusion 5 (FIG. 9B).

It can also be produced as follows. First, in the same manner as described above, the concave portion 4a is formed on one surface of the base material 4 ′ for forming the protective material 4 (FIG. 10A). Next, this concave portion 4a and a portion where the corridor-shaped convex portion 5 is formed in a subsequent process are covered with a resist pattern 9 (FIG. 10B). The resist pattern 9 has resistance to grinding or etching such as sandblasting in the subsequent process. For example, when wet etching is performed in the subsequent process, the resist 4 is formed from the base 4 'side with a chromium / chromium oxide / resin resist. A three-layer resist pattern 9 can be obtained. In this case, the two layers of chromium / chromium oxide can be formed into a pattern by vapor deposition through a mask, for example, and the resin resist can be formed by applying a photosensitive resist, exposing and developing. . Thereafter, the substrate 4 'is ground through the resist pattern 9 to form the clearance concave portion 4b and the convex portion 5 (FIG. 10C).
Further, as described in the above embodiment, the protective material 4 provided with the clearance concave portion 4b may be formed by melting the protective material, injecting it into a mold, and solidifying it.

The sensor chip manufacturing method of the present invention as described above is active even when the pressure is increased in order to obtain good adhesion when the protective members 4 and 14 are fixed via the convex portions 5 and 15. Surface 2A. 12A and the terminals 3 and 13 are not covered by the deformation of the projections 5 and 15, and the gap between the active surfaces 2A and 12A of the sensor bodies 2 and 12 and the protective materials 4 and 14 is made uniform. It is easy to manufacture, and it is possible to manufacture a sensor chip of high durability, small size and high quality.
In addition, the manufacturing method of the sensor chip of the above-mentioned this invention is an illustration, and this invention is not limited to these embodiment.

Next, the present invention will be described in more detail with specific examples.
[Example 1]
First, a silicon wafer having a thickness of 625 μm was prepared, and was divided into multiple faces with a size of 5 mm × 7 mm. Next, for each imposition of the silicon wafer, a solid-state imaging device (sensor body) (active surface dimensions: 3.88 mm × 5.88 mm) is produced by a conventional method, and then back grinding is performed from the back surface of the silicon wafer. The thickness was 500 μm. Each sensor body was provided with 20 terminals around the active surface.

  On the other hand, a glass substrate (compliant with 6-inch JEIDA standard silicon wafer dimensions) having a thickness of 550 μm was prepared. Next, a chromium film pattern was formed on one surface of the glass substrate (to improve adhesion), and a pattern was formed with an acid resistant resist (manufactured by Tokyo Ohka Kogyo Co., Ltd.) to obtain a mask. As a result, within each imposition of a 5 mm × 7 mm grid, stripes having a width of 100 μm intersect in a lattice pattern, and a 3.9 mm × 5.9 mm rectangular pattern non-formation site exists at the center of each imposition. Thus, a mask pattern was formed. Next, the glass substrate is wet etched by spraying hydrofluoric acid through the mask pattern, and then the mask pattern is removed using a resist stripper and a chromium stripper (both manufactured by Tokyo Ohka Kogyo Co., Ltd.). did. As a result, a convex portion having a corridor shape (4 mm × 6 mm) having a height of 50 μm and a width of 100 μm was formed to obtain a protective material.

Next, an adhesive (epoxy adhesive manufactured by Kyoritsu Chemical Industry Co., Ltd.) is applied to the tip of the convex portion of the protective material, and the convex portion is connected to the active surface of the sensor body and the region where the terminals are disposed. Then, it was irradiated with ultraviolet rays at 6000 mJ / cm ² . Thereby, the protective material was disposed on the sensor body. The gap between the provided protective material and the active surface of each sensor body was about 50 μm.
Next, using a diamond cutter, only the glass substrate at the boundary portion of each sensor body was ground and removed with a width of 1 mm. Thereby, it came to the state by which the protective material which consists of a glass substrate of 4 mm x 6 mm was arrange | positioned on the frame for sealing.
Next, the silicon wafer was diced with a diamond cutter to obtain the sensor chip of the present invention. This sensor chip had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small.

[Example 2]
In the same manner as in Example 1, a sensor main body was produced by applying multiple faces to a silicon wafer to obtain a wafer level sensor main body. Each sensor body was provided with 20 wiring pads around the active surface.
Next, a silicon nitride film (thickness 5 μm) was formed on the silicon wafer surface opposite to the active surface by plasma CVD. Next, a positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to the entire surface of the silicon nitride film, and exposed and developed through a photomask for forming fine through holes, thereby forming a resist pattern. Formed. Next, the silicon nitride film exposed from the resist pattern was dry-etched using CF ₄ as an etching gas, and then the resist pattern was peeled off to form a mask pattern made of silicon nitride on each surface. In the mask pattern, 20 circular openings having a diameter of 100 μm were formed so as to correspond to the wiring pads for each imposition.

Next, the silicon wafer exposed from the mask pattern was dry-etched with an ICP-RIE apparatus using SF ₆ as an etching gas to form fine through holes. This fine through-hole has a tapered shape with one opening diameter of 80 μm and the inner opening diameter of 40 μm, and the wiring pad is exposed in the inner part.
Next, the mask pattern was removed from the core material using acetone. Thereafter, a silicon nitride film was formed by a plasma CVD method in the fine through hole and on the silicon wafer surface opposite to the active surface, and a titanium nitride film was further formed by an MOCVD method to form an insulating film. Thereafter, a base conductive thin film having a thickness of 0.3 μm was formed from one surface of the silicon wafer (the side opposite to the active surface) by sputtering in the order of titanium-copper. Next, a dry film resist (APR manufactured by Asahi Kasei Co., Ltd.) was laminated on the underlying conductive thin film. Next, the resist pattern (thickness 15 μm) was formed by exposure and development through a photomask for forming front and back conductive vias. Using this resist pattern as a mask, the above-mentioned underlying conductive thin film was used as a power feeding layer, and electrolytic copper plating was performed to fill the inside of the fine through hole. Next, the resist pattern and the underlying conductive thin film were removed to form front and back conductive vias.

On the other hand, a glass substrate (compliant with 6-inch JEIDA standard silicon wafer dimensions) having a thickness of 550 μm was prepared. Next, a dry film resist (Liston A3100 manufactured by DuPont) having a thickness of 25 μm is laminated on one surface of the glass substrate using a laminating apparatus (MACH-600 manufactured by Hakuto Co., Ltd.), and 100 mJ / cm through a predetermined mask. Exposed at ² . Then, it developed with 1% sodium carbonate aqueous solution. As a result, within each imposition of a 5 mm × 7 mm grid, stripes having a width of 100 μm intersect in a lattice pattern, and a 3.9 mm × 5.9 mm rectangular pattern non-formation site exists at the center of each imposition. Thus, a mask pattern was formed. Next, sandblasting is performed on the glass substrate through the above mask pattern, and then flattening is performed by spraying and etching hydrofluoric acid, and then the mask pattern is removed using a 5% aqueous sodium hydroxide solution. did. As a result, a convex portion having a corridor shape (4 mm × 6 mm) having a height of 50 μm and a width of 100 μm was formed and used as a protective material.

Next, an adhesive (epoxy adhesive manufactured by Kyoritsu Chemical Industry Co., Ltd.) is applied to the tip of the convex portion of the protective material, and it is intermediate between the active surface of the sensor body and the area where the wiring pads are disposed. It was made to contact | abut to an area | region, and ultraviolet rays were irradiated after that at 6000 mJ / cm < ² >. Thereby, the protective material was disposed on the sensor body. The gap between the provided protective material and the active surface of each sensor body was about 50 μm.
Next, the silicon wafer and the glass substrate were diced with a diamond cutter to obtain the sensor chip of the present invention. This sensor chip had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small.

[Example 3]
A sensor chip of the present invention was obtained in the same manner as in Example 1 except that a protective material integrally having convex portions was produced as follows.
That is, the protective material was glass (AN100 manufactured by Asahi Glass Co., Ltd.) melted at 700 ° C., injected into a carbon mold, cooled to 25 ° C. and solidified, then taken out from the carbon mold, 650 It was fabricated by annealing (heat treatment) at a temperature. The produced protective material is provided with a convex portion having a corridor shape (4 mm × 6 mm) having a height of 50 μm and a width of 100 μm in each imposition of a 5 mm × 7 mm grid, and at a portion where no convex portion exists. The thickness was 500 μm.
The obtained sensor chip of the present invention had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small.

[Example 4]
First, the protective material provided with the recessed part for clearance was produced as follows.
A glass substrate (compliant with 6-inch JEIDA standard silicon wafer dimensions) having a thickness of 550 μm was prepared. Next, a chromium film pattern was formed on one surface of the glass substrate (to improve adhesion), and a pattern was formed with an acid resistant resist (manufactured by Tokyo Ohka Kogyo Co., Ltd.) to obtain a mask. As a result, a mask pattern was formed such that a rectangular pattern non-formation portion of 3.9 mm × 5.9 mm was present at the center of each imposition of the 5 mm × 7 mm grid. Next, the glass substrate is wet etched by spraying hydrofluoric acid through the mask pattern, and then the mask pattern is removed using a resist stripper and a chromium stripper (both manufactured by Tokyo Ohka Kogyo Co., Ltd.). did. As a result, a rectangular recess (3.9 mm × 5.9 mm) having a depth of 50 μm and forming a flat surface was formed. Next, using a grinding blade (width: 900 μm), the glass substrate is ground in a lattice shape along the boundary line of each imposition to form a substantially bowl-shaped clearance recess, and the corridor-shaped protrusion A protective material was formed. The thickness of the glass substrate in the deepest part of the formed clearance recess was 300 μm. In addition, the formed convex portion had a corridor shape (4 mm × 6 mm) having a height (height from the flat surface of the flat concave portion) of 50 μm and a width (width of the tip portion) of 100 μm.

  Next, a sensor chip of the present invention was obtained in the same manner as in Example 1 except that the above protective material was used. This sensor chip had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small. In addition, in the process of grinding and removing only the glass substrate at the boundary part of each sensor body with a width of 1 mm using a dicer, as described above, the clearance recess is formed, so the dimension stop cut is controlled. Compared to Example 1, it was easier.

  The present invention can be applied in various fields where a small and highly reliable sensor chip is required.

It is a schematic sectional drawing which shows one Embodiment of the sensor chip of this invention. It is a figure for demonstrating the corridor-shaped convex part with which the protective material was equipped. It is a schematic sectional drawing which shows other embodiment of the sensor chip of this invention. It is a schematic sectional drawing which shows other embodiment of the sensor chip of this invention. It is a figure which shows the example by which the sensor chip of this invention is mounted in a board | substrate. It is process drawing which shows one Embodiment of the manufacturing method of the sensor chip of this invention. It is process drawing which shows other embodiment of the manufacturing method of the sensor chip of this invention. It is process drawing which shows other embodiment of the manufacturing method of the sensor chip of this invention. It is process drawing which shows an example of preparation of a protective material. It is process drawing which shows the other example of preparation of a protective material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Sensor chip 2,12 ... Sensor main body 2A, 12A ... Active surface 3,13 ... Terminal 4,14 ... Protective material 4b ... Concave part for clearance 5,15 ... Convex part 6,16 ... Gap 17 ... Front and back conduction via 18 ... Fine through hole

Claims (4)

A step of producing an active surface and a sensor body having a plurality of terminals in an outer region of the active surface by multi-faceting;
Protection that has a multi-sided corridor-shaped convex part on one side, aligned with the imposition position of the sensor body, and a lattice-shaped clearance concave part outside the convex part for each imposition Producing a material;
Disposing the protective material on the sensor body by fixing the convex portion between the active surface of the sensor body and the terminal formation region;
Removing an unnecessary portion of the protective material in which the clearance concave portion exists between the convex portions for each imposition of the protective material;
Dicing the sensor body with multiple faces to obtain individual sensor chips, and
The clearance recess, Ri protective material between adjacent said projections Do an arch shape, and that a smaller than the thickness of the protective material of the thickness of the protective material is surrounded by the convex regions in the deepest portion A method of manufacturing a sensor chip, characterized in that it is formed as described above. In the step of manufacturing the protective material, one surface of the protective material is ground and / or etched into a grid shape to form a concave portion, and then the concave portion is etched and flattened, and the protective material between the concave portions is formed. The method for manufacturing a sensor chip according to claim 1, wherein the concave portion for clearance is formed to form the convex portion.   2. The method of manufacturing a sensor chip according to claim 1, wherein, in the step of manufacturing the protective material, the protective material is formed by melting and injecting the protective material material into a mold and solidifying. The method for manufacturing a sensor chip according to claim 3 , wherein a carbon mold is used as the mold.

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