JP2010010580A - Imaging module and method of manufacturing the same, and endoscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely adjust parallelism between a cover glass and an image pickup device. <P>SOLUTION: An imaging module includes: the image pickup device 21 with an effective pixel region 21a formed in a semiconductor chip; a frame-like spacer 22 that is mounted on the semiconductor chip 21 and surrounds the effective pixel region 21a; the cover glass adhering onto the spacer 22; and an adhesive material for joining the semiconductor chip 21 to the spacer 22. In the imaging module, pressure sensors 30 are provided at lower parts of at least three spacers at positions along the spacer 22. The adhesive material is cured when the pressure detection values of respective pressure sensors 30 become identical. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging module, a manufacturing method thereof, and an endoscope apparatus.

  As described in Patent Documents 1 and 2, an image sensor such as a CCD type or a CMOS type used in a digital camera or the like has a cover glass fixed on the light receiving surface of the image sensor at a slight distance. Since it is better to make this cover glass parallel to the light receiving surface of the image sensor, conventionally, at the time of manufacturing the image pickup module, a plurality of spacers are arranged around the light receiving surface of the image sensor, and the cover glass is placed on the spacer and placed in parallel. I try to put out a degree.

JP 2003-303946 A Japanese Patent Laid-Open No. 2002-270802

  The size of the image sensor used in a digital camera or the like is different from that of the image sensor attached to the distal end of the insertion portion of the endoscope device. In particular, the distal end portion of the endoscope device whose diameter has been reduced as in recent years. The attached image sensor has a semiconductor chip with a small size of about 2 mm square.

  When manufacturing an image pickup module having such a small image pickup device, the degree of parallelism between the two cannot be obtained only by adjusting a spacer between the image pickup device and the cover glass. That is, if the force that presses the cover glass toward the imaging element is biased, the parallelism will be different.

  An object of the present invention is to provide an imaging module manufacturing method capable of adjusting the parallelism between the cover glass and the imaging device with high accuracy, an imaging module manufactured by the manufacturing method, and an imaging module mounted therein. An object of the present invention is to provide an endoscope apparatus.

  An imaging module of the present invention includes an imaging element in which an effective pixel area is formed on a semiconductor chip, a frame-shaped spacer that is mounted on the semiconductor chip and surrounds the effective pixel area, and a cover glass that is bonded onto the spacer. And an adhesive module for bonding between the semiconductor chip and the spacer, wherein pressure sensors are provided at least under the spacer at three positions along the spacer, respectively. Features.

  The imaging module of the present invention is characterized in that the pressure sensor is a semiconductor pressure sensor formed on a surface portion of the semiconductor chip.

  The imaging module of the present invention is characterized in that the pressure sensor is manufactured by a manufacturing process of the effective pixel.

  In the method for manufacturing an imaging module according to the present invention, the cover glass placed on the adhesive material via the spacer is pressed toward the semiconductor chip, and the pressure detection values of the plurality of pressure sensors become the same pressure value. And the adhesive is solidified. Here, the “same pressure value” does not need to be a completely identical pressure value, and may be the same pressure value within the allowable accuracy and error range on the product.

  The manufacturing method of the imaging module of the present invention is characterized in that the adhesive is an ultraviolet curable resin or a thermosetting resin.

  In the method for manufacturing an imaging module according to the present invention, the cover glass having the same size as the semiconductor wafer is bonded to the semiconductor wafer on which the plurality of imaging elements are formed via the spacer, The imaging module is singulated.

  An endoscope apparatus according to the present invention is characterized in that the imaging module according to any one of the above is built in a distal end of an insertion portion.

  According to the present invention, it is possible to manufacture an imaging module that can accurately detect the parallelism between the cover glass and the imaging element at a low cost and can increase the parallelism between the two. Can be obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall view of an endoscope apparatus according to an embodiment of the present invention. The endoscope apparatus 1 includes a hand operation unit 2, an insertion unit 3 connected to the hand operation unit 2, and a connector unit 5 connected to the hand operation unit 2 via a flexible tube 4. Is provided.

  An imaging module (to be described later) is built in the distal end portion 3 a of the insertion portion 3, and an output signal line of this imaging module is inserted into the insertion portion 3, the hand operation portion 2, and the tube 4 to the connector portion 5. By connecting the connector unit 5 to a video processor (not shown), a video image taken by the imaging module is displayed on a monitor.

  FIG. 2 is a perspective view showing the front surface of the tip 3a shown in FIG. A forceps hole opening 7 is provided in the endoscope distal end portion 3a, and a treatment tool (not shown) inserted from the forceps hole inlet 8 shown in FIG.

  In addition, an objective lens 9 is provided at the endoscope distal end portion 3a, and light guides 10 and 11 for emitting illumination light are provided on both sides thereof. The air / water supply nozzle 12 provided on the side of the forceps hole opening 7 performs cleaning by jetting a liquid such as water onto the objective lens 9 when the objective lens 9 becomes dirty.

  In the endoscope apparatus 1 in recent years, the diameter of the insertion portion 3 is reduced, and the outer diameter of the distal end portion 3a is as thin as about 5 mm and 6 mm. Since the passage of the forceps hole opening 7, the optical fiber bundle of the light guides 10 and 11, the fluid passage to the air / water supply nozzle 12 and the like are inserted into the distal end portion 3 a, the imaging module mounted here is small-sized. I have to make it.

  FIG. 3 is a schematic view of an imaging device mounted in the distal end portion 3a. An objective lens 9 shown in FIG. 2 is provided at the distal end portion of the objective optical system 15 that takes in incident light from a subject, that is, reflected light of illumination light from the light guides 10 and 11, and an incident light exit end of the objective optical system 15. A prism 16 that bends the optical path at a right angle is provided, and a flat imaging module 17 is mounted on the lower end of the prism 16.

  FIG. 4 is a configuration diagram of the imaging module 17. The imaging module 17 is mounted on the imaging element 21 formed on the semiconductor chip, a rectangular frame-shaped spacer 22 placed so as to surround the periphery of the light receiving surface (effective pixel area) of the imaging element 21, and the spacer 22. A cover glass 23 placed thereon and a terminal substrate 24 disposed adjacent to the image sensor 21. A connection pad 29 (see FIG. 5) formed on the chip end of the image sensor 21 and a signal terminal ( (Not shown) is bonded by the wire 25.

  The space between the spacer 22 and the surface of the semiconductor chip on which the imaging element 21 is formed, or the space between the cover glass 23 and the spacer 22 is bonded by, for example, ultraviolet (UV) curable resin.

  5 is a top view of the imaging module 17, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. In the effective pixel region 21a formed in the center portion of the image sensor 21, a large number of pixels (not shown) are formed in a two-dimensional array. The means for reading the detection signal of each pixel is a CMOS circuit if it is a CMOS type, and a charge transfer path if it is a CCD type, but the image sensor 21 of this embodiment may be any signal reading means.

  Semiconductor pressure sensors 30 are provided in the vicinity of the four corners surrounding the effective pixel region 21a of the semiconductor chip on which the image sensor 21 is formed. The semiconductor pressure sensor 30 is a diffusion type sensor using, for example, a piezoresistive effect, and is formed on the surface portion of the semiconductor chip by the same process as the semiconductor process for forming the imaging element 21.

  A rectangular frame-shaped spacer 22 is placed on the semiconductor chip so as to surround the effective pixel region 21 a, and the four corners of the spacer 22 are placed on the semiconductor pressure sensor 30. Further, a transparent cover glass 23 is placed on the spacer 22. Outside the spacer 22, a connection pad 30 a of the pressure sensor 30 is also provided in addition to the connection pad 29 of the image sensor 21.

  When the imaging module according to the present embodiment is manufactured, the spacer 22 is placed on the semiconductor chip of the imaging element 21 after the UV curable resin 31 is thinly applied, and the UV curable resin is thinly applied thereon and then the cover glass is applied. 23 is placed. At this time, alignment is performed so that the four corners of the spacer 22 are on the pressure sensor 30.

  Then, the cover glass 23 is pushed toward the image sensor 21 from above the cover glass 23, and when the detection signal value of each pressure sensor 30 obtained through the pad 30a detects the same pressure value, the UV curable resin 31 is irradiated with ultraviolet rays. By doing so, the cover glass 23, the spacer 22, and the image pickup device 21 are bonded and integrated. Thereby, an imaging module in which the cover glass 23 and the light receiving surface 21a of the imaging element are parallel to each other is obtained.

  The height of the spacer 22 is manufactured to a uniform height with high accuracy over the entire circumference, and it is detected that the pressure sensors 30 at the four corners are pressed with the same pressure value within the allowable accuracy and error range. At that time, if the adhesive resin is cured, the parallelism between the cover glass 23 and the image sensor 21 is increased with high accuracy.

  In the present embodiment, since each pressure sensor 30 is manufactured on the same substrate by the same semiconductor process as that for manufacturing effective pixels, it can be manufactured at low cost, and manufacturing errors between the pressure sensors 30 are small. The pressure detection error is extremely small. If it is desired to further increase the parallelism between the cover glass 23 and the image sensor 21, the pressure detection error of each pressure sensor 30 is measured in advance, and the four pressure sensors are detected using the detected pressure values corrected based on the measured values. It is sufficient to detect 30 identical pressures.

  FIG. 7 is an explanatory diagram of a method for manufacturing an imaging module according to another embodiment of the present invention. In the embodiment described with reference to FIG. 6, in each of the imaging modules 17, the parallelism between the cover glass 23 and the imaging element 21 is adjusted, and the cover glass 23 is bonded to the imaging element 21 via the spacer 22.

  However, in the present embodiment, a plurality of image pickup devices 21 are manufactured on the wafer 40, and the lattice-shaped spacer coupling body is placed on the wafer 40 after thinly applying an ultraviolet curable resin, and the wafer is disposed on the spacer coupling body. A cover glass having the same diameter as 40 is placed.

  Among the plurality of image pickup elements 21 formed on the wafer 40, a plurality of image pickup elements 21 at discrete positions are selected, and one of the pressure sensors 30 of each image pickup element 21 (the dotted line illustrated in FIG. 7 is illustrated). Wiring is performed so that the detection value of the pressure sensor surrounded by a circle can be detected outside the wafer 40. This wiring is performed before the cover glass 23 is placed on the wafer 40.

  Then, the cover glass 23 is placed on the spacer coupling body and pressed, and when the detection pressure of the pressure sensor 30 to be detected becomes the same pressure, the resin is cured by irradiating ultraviolet rays.

  Thereafter, the wafer 40 is not cut, and only the spacer coupling body and the cover glass on the wafer 40 are diced with a slightly wider cutter, and then along the diced mark, this time with a thin cutter, the wafer 40 is cut. Dicing is performed. Thereby, the image pick-up element 21 is separated into pieces.

  In the above-described embodiment, the ultraviolet curable resin is described as an example. However, the thermosetting resin can be used for bonding.

  Moreover, although the example which forms the pressure sensor 30 in the semiconductor chip surface part was described, when a pressure sensor cannot be formed on a semiconductor chip, a pressure sensor is manufactured separately and this pressure sensor is formed in four corners of a spacer. The parallelism between the cover glass 23 and the image sensor 21 may be detected by placing it below.

  In the above-described embodiment, the imaging module mounted on the endoscope distal end has been described. However, the same manufacturing technique can also be applied to an imaging module mounted on a digital camera or the like.

  The method for manufacturing an imaging module according to the present invention is useful when applied to an imaging module mounted on an endoscope apparatus because the parallelism between the cover glass and the imaging element chip can be accurately obtained at low cost.

It is a lineblock diagram of an endoscope apparatus concerning one embodiment of the present invention. It is a perspective view which shows the endoscope front-end | tip front surface shown in FIG. It is a block diagram of the imaging optical system incorporated in the endoscope front-end | tip part. It is a block diagram of the imaging module shown in FIG. It is a top view of an imaging module. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is explanatory drawing of the manufacturing method of the imaging module in a wafer state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus 3 Insertion part 3a Insertion part front-end | tip (endoscope front-end | tip)
DESCRIPTION OF SYMBOLS 9 Objective lens 15 Objective optical system 16 Prism 17 Imaging module 21 Imaging element 22 Spacer 23 Cover glass 30 Pressure sensor 31 Adhesive resin 40 Semiconductor wafer

Claims (7)

  An image sensor in which an effective pixel region is formed on a semiconductor chip, a frame-shaped spacer mounted on the semiconductor chip and surrounding the effective pixel region, a cover glass bonded on the spacer, the semiconductor chip, and the semiconductor chip An imaging module comprising an adhesive for adhering to a spacer, wherein pressure sensors are provided at lower portions of the spacer at least at three positions along the spacer.   2. The imaging module according to claim 1, wherein the pressure sensor is a semiconductor pressure sensor formed on a surface portion of the semiconductor chip.   The imaging module according to claim 2, wherein the pressure sensor is manufactured by a manufacturing process of the effective pixel.   A method for manufacturing the imaging module according to any one of claims 1 to 3, wherein the cover glass placed on the adhesive material via the spacer is pressed toward the semiconductor chip, and a plurality of the imaging modules are manufactured. The method for manufacturing an imaging module, wherein the adhesive is solidified when the pressure detection values of the pressure sensors become the same pressure value.   5. The method for manufacturing an imaging module according to claim 4, wherein the adhesive is an ultraviolet curable resin or a thermosetting resin.   The manufacturing method of the imaging module according to claim 4 or claim 5, wherein the cover glass having the same size as the semiconductor wafer is bonded to the semiconductor wafer on which the plurality of imaging elements are formed via the spacer. Thereafter, the imaging module manufacturing method, wherein each of the imaging modules is separated into pieces.   An endoscope apparatus comprising the imaging module according to any one of claims 1 to 3 built in a distal end of an insertion portion.

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