JP6157211B2 - Manufacturing method of imaging apparatus - Google Patents

Description

The present invention relates to the production how the imaging device optical member comprises an imaging chip bonded on the light receiving portion.

  An imaging apparatus including an imaging chip is used, for example, provided at the distal end portion of an electronic endoscope. Reduction of the diameter of the distal end portion of the endoscope is an important issue, and downsizing of the imaging device is required.

  First, a wafer level packaging type imaging apparatus will be briefly described for comparison. A wafer level packaging type imaging apparatus is manufactured by cutting and separating a bonded wafer obtained by bonding an imaging wafer including a plurality of imaging chips and a glass wafer. For this reason, the whole surface of the 1st main surface in which the light-receiving part of the imaging chip was formed is covered with the cover glass. The electrode pad for transmitting and receiving signals to and from the light receiving unit needs to be formed on the second main surface (back surface) through the through wiring. However, the through wiring formation process is a complicated process including through hole formation, insulation layer formation, conductor layer formation, and the like.

  Japanese Patent Application Laid-Open No. 2008-118568 discloses an imaging device in which a light receiving portion and an electrode pad are disposed on a first main surface. Unlike the wafer level packaging type imaging apparatus, this imaging apparatus does not require the formation of through wiring, and is easy to produce. However, the cover glass for protecting the light receiving part of the imaging chip needs to be positioned and bonded so as not to cover the electrode pad. However, if the side of the imaging chip is as small as several mm or less, the cover glass is received. It is not easy to accurately position and bond so as to cover the part and not the electrode pad. If the cover glass having a larger size in plan view than the imaging chip is bonded in consideration of the positioning accuracy, the outer size of the imaging device is increased.

Therefore, a light receiving portion and the electrode pads are disposed on the main surface, producing how the imaging apparatus an imaging device receiving portion is covered with a cover glass can be easily produced has been demanded.

JP 2008-118568 A

The present invention aims to provide a manufacturing how the small-sized image pickup apparatus and image pickup apparatus can be easily manufactured.

  The manufacturing method of the imaging device according to the embodiment of the present invention is a rectangle having a short side and a long side in a plan view, and a plurality of light receiving units are formed in two rows parallel to the long side at the center in the short side direction. A step of producing an imaging substrate in which a plurality of electrode groups including a plurality of electrode pads connected to the respective light receiving portions are arranged along the long side on the outer peripheral side of each light receiving portion; A step of manufacturing a rectangular optical substrate having a width in a plan view that covers two rows of the light receiving portions and does not cover the two rows of electrode groups; and the optical substrate is transparent so as not to cover the electrode groups on the imaging substrate. A step of bonding through an adhesive layer to produce a bonded substrate; and a step of cutting the bonded substrate and dividing it into a plurality of imaging devices.

According to the present invention can provide a manufacturing how the small-sized image pickup apparatus and image pickup apparatus can be easily manufactured.

It is a perspective view of the imaging device of a 1st embodiment. It is a top view of the imaging device of a 1st embodiment. It is sectional drawing of the imaging device of 1st Embodiment. It is a flowchart for demonstrating the manufacturing method of the imaging device of 1st Embodiment. It is a top view of the imaging chip wafer for explaining the manufacturing method of the imaging device of a 1st embodiment. It is a figure for demonstrating the manufacturing method of the imaging device of 1st Embodiment. (A) is a top view of an imaging board, (B) is a sectional view. It is a figure for demonstrating the manufacturing method of the imaging device of 1st Embodiment. (A) is a top view of an imaging board, (B) is a sectional view. It is a disassembled perspective view for demonstrating the manufacturing method of the imaging device of 1st Embodiment. It is a figure for demonstrating the manufacturing method of the imaging device of 1st Embodiment. (A) is a top view of an imaging board, (B) is a sectional view. It is sectional drawing for demonstrating the manufacturing method of the imaging device of the modification of 1st Embodiment. It is sectional drawing for demonstrating the manufacturing method of the imaging device of the modification of 1st Embodiment. It is a top view of the imaging device of the modification of 1st Embodiment. It is sectional drawing of the imaging device of the modification of 1st Embodiment. It is a disassembled perspective view for demonstrating the manufacturing method of the imaging device of 2nd Embodiment. It is sectional drawing for demonstrating the manufacturing method of the imaging device of the modification of 2nd Embodiment. It is sectional drawing for demonstrating the manufacturing method of the imaging device of the modification of 2nd Embodiment. It is a disassembled perspective view for demonstrating the manufacturing method of the imaging device of 3rd Embodiment. It is sectional drawing of the imaging device of 3rd Embodiment.

<First Embodiment>
<Structure of imaging device>
As shown in FIG. 1, FIG. 2A and FIG. 2B, the imaging device 1 of the present embodiment includes an imaging chip 10 and a cover glass 30 that is an optical member bonded to the imaging chip 10 through an adhesive layer 20. A signal cable 40 joined to the electrode pad 12 of the imaging chip 10.

  The rectangular parallelepiped imaging chip 10 includes a first main surface 10SA, a second main surface 10SB, a first side surface 10S1, a second side surface 10S2, a third side surface 10S3, and a fourth side surface 10S4. . The first main surface 10SA of the imaging chip 10 includes a light receiving unit 11 made of a CMOS image sensor and the like, and an electrode group 12S made up of a plurality of electrode pads 12 each connected to the light receiving unit 11 by wiring (not shown). Is formed. The plurality of electrode pads 12 are arranged in parallel to the first side surface 10S1.

  The transparent cover glass 30 is also a rectangular parallelepiped and has a first side surface 30S1, a second side surface 30S2, a third side surface 30S3, and a fourth side surface 30S4. The cover glass 30 is bonded to the imaging chip 10 via the transparent adhesive layer 20 so as to cover the light receiving unit 11 and not the electrode group 12S.

  In the imaging device 1, the three side surfaces (30S2, 30S3, 30S4) of the cover glass 30 and the three side surfaces (10S2, 10S3, 10S4) of the imaging chip 10 are aligned with each other, and the same planar view position It is in.

  In other words, the distance D2 between the second side surface 30S2 of the cover glass 30 and the second side surface of the imaging chip 10, and the distance D3 between the third side surface 30S3 of the cover glass 30 and the third side surface of the imaging chip 10 The distance D4 between the fourth side surface 30S4 of the cover glass 30 and the fourth side surface of the imaging chip 10 is zero.

  The image pickup apparatus 1 has the same plan view size as the image pickup chip 10 having a plan view size of several mm or less, for example, 1 mm, and is small. That is, a cover glass 30 having a smaller size in plan view than the imaging chip 10 is bonded so as to cover the light receiving unit 11 and not to cover the electrode pad 12 that transmits and receives signals to and from the light receiving unit 11.

  The imaging apparatus 1 can be regarded as having the cover glass 30 adhered to the imaging chip 10 in a state of being very accurately aligned, and is small in size. This is because the imaging device 1 is manufactured by a manufacturing method described later.

<Method for Manufacturing Imaging Device>
Next, the manufacturing method of the imaging device 1 will be described along the flowchart of FIG.

<Step S11> Imaging Substrate Fabrication An imaging wafer 10W including a plurality of imaging chips 10 shown in FIG. 4 is fabricated using a known semiconductor manufacturing technique on the main surface of a wafer made of a semiconductor such as silicon. The imaging wafer 10W has a great feature in the arrangement of a plurality of imaging chips 10 on the wafer.

  That is, a plurality of light receiving portions 11 made of CMOS image sensors or the like are formed in two rows in parallel, and a plurality of electrode pads 12 connected to each light receiving portion 11 are arranged on the outer peripheral side of each light receiving portion 11. A plurality of provided electrode groups 12S are formed.

  The imaging substrate 10S (see FIGS. 5 and 6) is manufactured by cutting the imaging wafer 10W. The planar view shape of the imaging substrate 10S is a rectangle including a short side having a width W10S and a long side having a length LS. The imaging substrate 10 </ b> S has a plurality of light receiving portions 11 formed in two rows parallel to the side at the central portion in the short side direction, and a plurality of light receiving portions 11 connected to the respective light receiving portions 11 on the outer peripheral side of each light receiving portion 11. A plurality of electrode groups 12S composed of the electrode pads 12 are arranged along the long side.

  The imaging substrate 10 </ b> S illustrated in FIGS. 5 to 8 includes 16 imaging chips 10. The imaging substrate 10S preferably includes 4 or more and 140 or less imaging chips 10. If the imaging chip 10 is above, the productivity is excellent. If the imaging chip 10 is below, it is easy to position the imaging substrate 10S using a general semiconductor mounting apparatus and perform adhesion, additional processing, or the like. It is.

<Step S12> Production of Optical Substrate A glass wafer made of glass is cut based on the planar view dimensions of the imaging substrate 10S, and a glass substrate 30S which is a rectangular parallelepiped optical substrate is produced (see FIG. 7). The imaging wafer 10W and the glass wafer may be different in shape and size.

The glass substrate 30S has a width W30S that covers the two rows of light receiving portions 11 of the imaging substrate 10S and does not cover the two rows of electrode groups 12S, and the length L30S is the same as or slightly longer than the length L10S of the imaging substrate 10S.
Note that step S11 (imaging substrate fabrication) and step S12 (optical substrate fabrication) may be reversed.

<Step S13> Adhesion As shown in FIGS. 6 and 7, the glass substrate 30S is adhered to the imaging substrate 10S via the transparent adhesive layer 20S so as not to cover the electrode group 12S, thereby producing the bonded substrate 1S. . The glass substrate 30S and the imaging substrate 10S can be positioned and bonded using a general electronic component mounting apparatus.

  For the adhesive layer 20, for example, an epoxy-based, acrylic-based, or silicone-based ultraviolet curable resin or thermosetting resin can be used. The state before curing may be either liquid or film.

<Step S <b>14> Cutting As shown in FIG. 8, the bonded substrate 1 </ b> S is cut and separated into a plurality of imaging devices 1. Then, the signal cable 40 is joined to each of the plurality of electrode pads 12.
The signal cable 40 may be bonded to the bonding substrate 1S.

  As described above, the imaging device 1 has three side surfaces (30S2, 30S3, 30S4) of the cover glass 30 and second to fourth side surfaces (10S2, 10S3, 10S4) of the imaging chip 10 having end surfaces. They are all in the same plan view position.

  That is, since the three side surfaces (30S2, 30S3, 30S4) of the cover glass 30 and the three side surfaces (10S2, 10S3, 10S4) of the imaging chip 10 are simultaneously formed by cutting the bonded substrate 1S, It is the same state as being correctly aligned.

  According to the manufacturing method of the embodiment, the small-sized imaging device 1 in a state where the cover glass 30 and the imaging chip 10 are accurately aligned can be easily manufactured.

<Modification of First Embodiment>
Next, an imaging device 1A according to a modification of the first embodiment and a method for manufacturing the imaging device 1A will be described. Since the imaging device 1A and the like are similar to the imaging device 1, the same components are denoted by the same reference numerals and description thereof is omitted.

  The imaging apparatus 1A is slightly different from the imaging apparatus 1 in the cutting process, and a so-called step cut method is used. That is, the cutting step includes a first cutting step (FIG. 9A) for cutting the glass substrate 30S with a first cutting margin W1 and a second cutting margin W2 narrower than the first cutting margin W1. And a second cutting step (FIG. 9B) for cutting the imaging substrate 10 </ b> S.

  The optimum cutting conditions for the glass substrate 30S are different from the optimum cutting conditions for the imaging substrate 10S. That is, since glass and silicon are materials having different hardnesses, chipping or the like may occur if they are cut simultaneously under the same conditions. Moreover, in order to prevent chipping etc., it is necessary to process at low speed.

  On the other hand, since the imaging apparatus 1A performs the cutting by the step cut method, there is no possibility of occurrence of chipping and the like, and the first cutting process and the second cutting process can be performed at high speed. The adhesive layer 20S is cut in the first cutting process or the second cutting process.

  The manufacturing method of the imaging device 1A has the same effect as the manufacturing method of the imaging device 1A, and is further excellent in productivity.

  10A and 10B show the imaging apparatus 1A cut by the step cut method.

  In the imaging apparatus 1A, the cover glass 30A is bonded via the adhesive layer 20A so as not to cover the electrode group 12S, and the three side surfaces 30S2 to 30S4 are the second to fourth side surfaces of the imaging chip 10, respectively. It is located on the inner peripheral side of 10S2 to 10S4.

  Then, a distance D2 between the second side surface 30S2 of the cover glass 30 and the second side surface of the imaging chip 10, a distance D3 between the third side surface 30S3 of the cover glass 30 and the third side surface of the imaging chip 10, A distance D4 between the fourth side surface 30S4 of the cover glass 30 and the fourth side surface of the imaging chip 10 is substantially the same. That is, the distance between the side surfaces is D2≈D3≈D4≈ ((W1-W2) / 2).

  The imaging device 1A has the same effect as the imaging device 1A.

  9A to 10B, in the imaging apparatus 1A, the adhesive layer 20A (20SA) does not cover the light receiving unit 11. That is, a space 20V is formed on the light receiving unit 11. A gas such as air may exist in the space 20V, or a vacuum state may be used.

  The light receiving unit 11 is provided with a microlens (not shown). When the outer surface of the microlens is covered with an adhesive layer, the lens effect is reduced. However, since the space 20V is formed in the imaging device 1A, the lens effect is not impaired.

  In the imaging device of another embodiment, it is preferable that the adhesive layer does not cover the light receiving unit 11 when a microlens is provided in the light receiving unit 11. In addition, a color filter may be disposed in the light receiving unit 11.

Second Embodiment
Next, the imaging device 1B of the second embodiment and the method for manufacturing the imaging device 1B will be described. Since the imaging device 1B and the like are similar to the imaging device 1, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 11 and 12A, the optical substrate 30SB manufactured in the method for manufacturing the imaging device 1B is made of glass and has a rod shape with a substantially right-angled isosceles triangle section.

  For this reason, as illustrated in FIG. 12B, in the imaging device 1 </ b> B manufactured by cutting the bonded substrate 1 </ b> SB, a prism 30 </ b> B that is an optical member is bonded to the imaging chip 10.

  Light from the direction parallel to the light receiving unit 11 is reflected by the right-angle prism 30B, the optical path is changed by 90 degrees, and is incident on the light receiving unit 11. The imaging device 1B is a perspective type or horizontal type imaging device.

  The imaging device 1B has the effect of the imaging device 1, and further has high functionality because the prism 30B is bonded as an optical member.

  Further, the imaging device 1B is smaller in height and smaller than an imaging device in which a prism is further bonded to a cover glass.

<Third Embodiment>
Next, an imaging device 1C according to the third embodiment and a method for manufacturing the imaging device 1C will be described. Since the imaging device 1C and the like are similar to the imaging device 1, the same components are denoted by the same reference numerals and description thereof is omitted.

  As illustrated in FIG. 13, the optical substrate 30SC manufactured in the manufacturing method of the imaging device 1C includes a plurality of lenses 30C that are imaging optical systems of the light receiving unit 11.

  As shown in FIG. 14, in the imaging device 1 </ b> C manufactured by cutting the bonded substrate 1 </ b> SC, a lens 30 </ b> C that is an imaging optical system as an optical member is bonded to the imaging chip 10. The functional part of the lens 30C is substantially circular, but the lens 30C produced by cutting is rectangular in plan view.

  The imaging device 1C has the effect of the imaging device 1, and has a high added value because the optical member bonded to the imaging chip 10 is a high-function lens 30C. In addition, as an optical member to be used, the cover glass 30 in the first embodiment may be used together with the lens 30C in the present embodiment, and in addition to the optical member in the first to third embodiments, an IR cut filter and A filter such as a low-pass filter may be used.

  The imaging device and the like according to the above-described embodiment can be preferably used for an imaging device disposed at the distal end portion of an electronic endoscope because of its small size.

  The present invention is not limited to the above-described embodiments and modifications, and various changes and modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1, 1A-1C ... Imaging device, 1S, 1SB, 1SC ... Bonding substrate, 10 ... Imaging chip, 10S ... Imaging substrate, 10S1-10S4 ... Side surface, 10SA, 10SB ... Main surface, 10W ... Imaging wafer, 11 ... Light receiving part , 12 ... Electrode pad, 12S ... Electrode group, 20, 20A, 20S ... Adhesive layer, 20V ... Space, 30, 30A ... Cover glass, 30B ... Prism, 30C ... Lens, 30S ... Glass substrate, 30SB, 30SC ... Optical substrate , 30S1 to 30S4 ... side, 40 ... signal cable

Claims (6)

A rectangular shape having a short side and a long side in a plan view, a plurality of light receiving parts are formed in two rows parallel to the long side in the central part in the short side direction, A step of producing an imaging substrate in which a plurality of electrode groups each composed of a plurality of electrode pads connected to the light receiving unit are arranged along the long side;
Producing a rectangular optical substrate in plan view with a width that covers two rows of the light receiving portions and does not cover the two rows of electrode groups;
Bonding the optical substrate to the imaging substrate via a transparent adhesive layer so as not to cover the electrode group, and producing a bonded substrate;
And a step of cutting the bonded substrate into a plurality of image pickup devices, and manufacturing the image pickup device.   The bonding substrate cutting step includes a first cutting step of cutting the optical substrate at a first cutting margin and a second cutting margin narrower than the first cutting margin to cut the imaging substrate. The manufacturing method of the imaging device according to claim 1, comprising two cutting steps.   The method of manufacturing an imaging apparatus according to claim 1, wherein the optical substrate is made of glass.   The method for manufacturing an imaging device according to any one of claims 1 to 3, wherein the adhesive layer does not cover the light receiving unit.   5. The method of manufacturing an imaging device according to claim 1, wherein the optical substrate becomes a prism by cutting the bonding substrate. 6.   The method of manufacturing an imaging apparatus according to claim 1, wherein the optical substrate includes an imaging optical system of each of the light receiving units.

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