IMAGE SENSOR, METHOD OF MANUFACTURING THE SAME, AND ELECTRONIC APPARATUS
The present disclosure relates to an image sensor, a method of manufacturing the image sensor, and an electronic apparatus where reliability of the image sensor can be further improved. The image sensor includes: a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner; a sealing resin applied to a side of the sensor surface of the sensor substrate; sealing glass bonded to the sensor substrate via the sealing resin; and a reinforcing resin made of a resin material having higher rigidity than the sealing resin and formed on an outer periphery of the sealing resin to bond the sensor substrate and the sealing glass. The sealing resin is formed to have a smaller area than each of the sensor substrate and the sealing glass, so that the reinforcing resin is formed to fill a gap provided on the outer periphery of the sealing resin, the sensor substrate and the sealing glass facing each other through the gap. The present technology can be applied to a CMOS image sensor, for example.
The present disclosure relates to an image sensor, a method of manufacturing the image sensor, and an electronic apparatus, and particularly to an image sensor, a method of manufacturing the image sensor, and an electronic apparatus where reliability of the image sensor can be further improved.
BACKGROUND ARTA conventional solid-state imaging device, which is one of the major optical devices, includes an optical element having a large number of photodiodes and microlenses on a semiconductor wafer, and is formed by forming electrical wiring and then molding the wafer airtight with glass. Such a solid-state image sensor is used as a photosensor of a digital video device such as a digital still camera, a mobile phone camera, or a digital video camera.
Moreover, a recent solid-state imaging device has a structure adopting a wafer level chip size package (CSP) technology in which electrical connection is secured by forming through electrodes and rewiring in assembly processing of the sensor in a wafer state. The solid-state imaging device formed by the wafer level CSP technology allows the video device to have smaller size and thickness as well as higher density packaging compared to a ceramic or plastic package which secures electrical connection by die bonding or wire bonding as in the related art.
Patent Document 1 for example discloses a method of manufacturing an image sensor by applying a sealing resin to a substrate in a wafer state, bonding glass thereto, thermosetting the sealing resin, and then dicing and cutting out the wafer into individual pieces.
CITATION LIST Patent Document
- Patent Document 1: Japanese Patent Application Laid-Open No. 2009-64839
Now, in the aforementioned method of manufacturing the sensor by bonding glass to the substrate in the wafer state and then curing the sealing resin, the use of a sealing resin having high rigidity causes an increase in warpage of the wafer by thermal contraction at the time of curing the resin and thus sometimes causes a problem at the time of transferring the wafer. On the other hand, the use of a sealing resin having low rigidity causes an increase in the deformation of the sealing resin at low temperature due to a difference in linear expansion coefficients between glass and the sensor substrate in a low temperature reliability test on the image sensor after being diced into individual pieces, whereby peeling is more likely to occur in some cases.
It is thus required to improve the reliability of the image sensor by preventing such a problem arising at the time of transferring the wafer as well as preventing the peeling from occurring easily.
The present disclosure has been made in view of such circumstances, and is intended to further improve the reliability of the image sensor.
Solutions to ProblemsAn image sensor according to one aspect of the present disclosure includes: a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner; a seal member applied to a side of the sensor surface of the sensor substrate; a sealing member bonded to the sensor substrate via the seal member; and a reinforcing member made of a material having higher rigidity than the seal member and formed on an outer periphery of the seal member to bond the sensor substrate and the sealing member.
In a manufacturing method according to one aspect of the present disclosure, a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner is bonded to a sealing member via a seal member applied on a side of the sensor surface of the sensor substrate, the method including a step of forming, on an outer periphery of the seal member, a reinforcing member made of a material having higher rigidity than the seal member to bond the sensor substrate and the sealing member.
An electronic apparatus according to one aspect of the present disclosure includes: a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner; a seal member applied to a side of the sensor surface of the sensor substrate; a sealing member bonded to the sensor substrate via the seal member; and a reinforcing member made of a material having higher rigidity than the seal member and formed on an outer periphery of the seal member to bond the sensor substrate and the sealing member.
In one aspect of the present disclosure, the seal member is applied to the side of the sensor surface, on which the photodiode is arranged in a planar manner, of the sensor substrate, which is then bonded to the sealing member via the seal member, and the reinforcing member made of a material having higher rigidity than the seal member is formed on the outer periphery of the seal member to bond the sensor substrate and the sealing member.
Effects of the InventionAccording to one aspect of the present disclosure, the reliability of the image sensor can be further improved.
Specific embodiments to which the present technology is applied will now be described in detail with reference to the drawings.
As illustrated in B of
The support substrate 12 is bonded to the surface of the sensor substrate 13 processed with a thin film from the back side, and supports the sensor substrate 13.
The sensor substrate 13 is provided with the sensor surface 18, on which a plurality of photodiodes is arranged in a planar manner, on the backside of the substrate and outputs a pixel signal corresponding to light received by each photodiode through the wiring layer laminated on the surface side of the substrate.
The sealing resin 14 is formed by applying a resin material having low rigidity to the backside of the sensor substrate 13 in order to bond the sealing glass 16 to the sensor surface 18 of the sensor substrate 13. Moreover, the sealing resin 14 is formed to have a smaller area than each of the sensor substrate 13 and the sealing glass 16, so that a concave groove is formed along the side surfaces of the image sensor 11 on the outer periphery of the sealing resin 14.
As illustrated in A of
The sealing glass 16 molds the sensor surface 18 of the sensor substrate 13 airtight. Note that the sealing glass 16 may be formed of a member that transmits light and thus be a sealing member made of material other than glass.
The image sensor 11 configured as described above uses the sealing resin 14 having low rigidity as the main component bonding the sensor substrate 13 and the sealing glass 16 to thus be able to prevent warpage by thermal contraction at the time of curing the resin and a problem at the time of wafer transfer. Moreover, the image sensor 11 uses the reinforcing resin 15 having high rigidity to reinforce the bond strength between the sensor substrate 13 and the sealing glass 16 on the outer periphery of the sealing resin 14, thereby preventing the sealing resin 14 from peeling off in a low temperature reliability test. The reliability of the image sensor 11 can thus be improved.
Next, a method of manufacturing the image sensor 11 will be described with reference to
First, as illustrated in the uppermost diagram of
In a first step, the substrate 21 is cut along a broken line to be formed into the image sensor 11 that is diced into a predetermined size as illustrated in the second diagram from the top in
Next, in a second step, the resin on the outer periphery of the sealing resin 14 is removed by laser ablation or an encapsulation remover, for example. This step forms the image sensor 11 with the groove formed by the sealing resin 14 on the side surfaces of the sensor, as illustrated in the third diagram from the top in
Then in a third step, a jet dispenser is used to apply a resin material, which is to be the reinforcing resin 15, to the groove formed by the sealing resin 14, and then the resin material is cured to be formed into the reinforcing resin 15 as illustrated in the fourth diagram from the top in
After that, in a fourth step, the through electrodes 17-1 and 17-2 of the image sensor 11 are electrically connected to a mounting substrate 31 by solder 32-1 and 32-2 as illustrated in the fifth diagram from the top in
Note that in applying the resin material with the jet dispenser, the resin material may be applied in a larger amount so as to protrude from the groove formed by the sealing resin 14 and then be cured, as illustrated in the upper diagram of
The manufacturing method including the aforementioned steps can manufacture the image sensor 11 with high reliability as described above.
The image sensor 11 for example uses the groove formed by the sealing resin 14 to be able to let the resin material for forming the reinforcing resin 15 stay in the groove. That is, the resin material applied to the side surface possibly drips in a configuration not including such a groove, whereas in the image sensor 11, the reinforcing resin 15 can be formed stably without the resin material dripping.
Moreover, the groove formed on the outer periphery of the sealing resin 14 is deep enough to prevent the reinforcing resin 15 from blocking the light condensed on the sensor surface 18 of the sensor substrate 13 through an optical system not shown, for example. Furthermore, the reinforcing resin 15 may be made of a resin material having higher rigidity than the sealing resin 14, preferably a resin material having the rigidity of about 10 to 100 times the rigidity of the sealing resin 14, for example.
Still furthermore, the configuration of the image sensor 11 is not limited to the aforementioned configuration in which the reinforcing resin 15 is formed in the groove as long as the reinforcing resin 15 can be formed to allow the sensor substrate 13 and the sealing glass 16 to be bonded to each other on the outer periphery of the sealing resin 14.
Next,
First, there is prepared a substrate 21 similar to that of
The thickness of the broken line illustrated in the uppermost diagram of
Thus, as illustrated in the second diagram from the top in
Then in a second step, a jet dispenser is used to apply a resin material to be a reinforcing resin 15A, and then the resin material is cured to be formed into the reinforcing resin 15A as illustrated in the third diagram from the top in
At this time, the support substrate 12A, the sensor substrate 13A, and the sealing resin 14 are each formed to have a smaller area than the sealing glass 16 so that the difference in level is formed between the side surfaces of the support substrate 12A, the sensor substrate 13A, and the sealing resin 14 and the side surface of the sealing glass 16. The reinforcing resin 15A is formed to fill such a difference in level. That is, the reinforcing resin 15A is formed so as to bond the side surfaces of the support substrate 12A, the sensor substrate 13A, and the sealing resin 14 to the bottom surface of the sealing glass 16. Although not shown, the image sensor 11A is thereafter connected to a mounting substrate 31 as is the case in
The manufacturing method including the aforementioned steps can manufacture the image sensor 11A with high reliability similar to the image sensor 11 of
Next,
First, there is prepared a substrate 21 similar to that of
The thickness of the broken line illustrated in the uppermost diagram of
Thus, as illustrated in the second diagram from the top in
Then in a second step, a jet dispenser is used to apply a resin material to be a reinforcing resin 15B, and then the resin material is cured to be formed into the reinforcing resin 15B as illustrated in the third diagram from the top in
At this time, the sealing resin 14 and the sealing glass 16B are each formed to have a smaller area than each of the support substrate 12 and the sensor substrate 13 so that the difference in level is formed between the side surfaces of the sealing resin 14 and sealing glass 16B and the side surfaces of the support substrate 12 and sensor substrate 13. The reinforcing resin 15B is formed to fill such a difference in level. That is, the reinforcing resin 15B is formed so as to bond the side surfaces of the sealing resin 14 and the sealing glass 16B to the upper surface of the sensor substrate 13. Although not shown, the image sensor 11B is thereafter connected to a mounting substrate 31 as is the case in
The manufacturing method including the aforementioned steps can manufacture the image sensor 11B with high reliability similar to the image sensor 11 of
Next,
First, there is prepared a substrate 21 similar to that of
As a result, the image sensor 11C with a flat side surface is formed as illustrated in the second diagram from the top in
Then in a second step, through electrodes 17-1 and 17-2 of the image sensor 11C are electrically connected to a mounting substrate 31 by solder 32-1 and 32-2 as illustrated in the third diagram from the top in
After that, in a third step, a jet dispenser is used to fill a gap between the image sensor 11C and the mounting substrate 31 while applying a resin material to be a reinforcing resin 15C from the upper surface of the mounting substrate 31 up to the side surface of the image sensor 11C, and then the resin material is cured to be formed into the reinforcing resin 15C. The reinforcing resin 15C is thus formed to bond the sensor substrate 13 and the sealing glass 16 together.
That is, the image sensor 11C uses as the reinforcing resin 15C an underfill material filling the gap between the image sensor 11C and the mounting substrate 31. Here, the underfill material made of a resin material having higher rigidity than the sealing resin 14 is generally applied to the gap between the image sensor 11C and the mounting substrate 31 for the purpose of preventing oxidation of solder or cracks of solder at the time of impact, and is used for protecting the solder. The underfill material thus has rigidity higher than that of the sealing resin 14, or rigidity suitable for use as the reinforcing resin 15C. Accordingly, the underfill material is used as the reinforcing resin 15C and applied at once to be able to form the reinforcing resin 15C without adding a new step.
Moreover, the image sensor 11C not provided with a groove or difference in level on the side surface can use the upper surface of the mounting substrate 31 to pile up the resin material at least up to a part of the sealing glass 16 to be able to form the reinforcing resin 15C that bonds the sensor substrate 13 and the sealing glass 16 together.
The manufacturing method including the aforementioned steps can manufacture the image sensor 11C with high reliability similar to the image sensor 11 of
Note that the image sensor 11 according to the aforementioned embodiments can be applied to various electronic apparatuses including an imaging system such as a digital still camera or a digital video camera, a mobile phone equipped with an imaging function, or another device equipped with the imaging function, for example.
As illustrated in
The optical system 102 includes one or a plurality of lenses to guide image light (incident light) from a subject to the image sensor 103 and form an image on a light-receiving surface (sensor part) of the image sensor 103.
The image sensor 11 of the aforementioned embodiments is applied as the image sensor 103. The image sensor 103 accumulates electrons for a certain period of time in accordance with the image formed on the light-receiving surface via the optical system 102. A signal corresponding to the electrons accumulated in the image sensor 103 is then supplied to the signal processing circuit 104.
The signal processing circuit 104 performs various types of signal processing on a pixel signal output from the image sensor 103. An image (image data) obtained after the signal processing performed by the signal processing circuit 104 is supplied to the monitor 105 and displayed thereon or supplied to the memory 106 and stored (recorded) therein.
The imaging device 101 configured as described above uses the image sensor 11 of the aforementioned embodiments to be able to perform imaging more reliably as a result of the improvement in the reliability of the image sensor 11.
The aforementioned image sensor can be used in various cases for sensing light such as visible light, infrared light, ultraviolet light, an X-ray, and the like as described below, for example.
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- A device such as a digital camera or a portable device with a camera function for photographing an image to be used for viewing
- A device for use in transportation such as an in-vehicle sensor that photographs the front, back, periphery, interior and the like of a vehicle for safe driving such as automatic stop, recognizing the condition of a driver, or the like, a surveillance camera that monitors traveling vehicles and roads, or a range sensor that measures the distance between vehicles and the like
- A device for use in home appliances such as a TV, a refrigerator, and an air conditioner to photograph a gesture of a user and operate an appliance in accordance with the gesture
- A device for use in medical and health care such as an endoscope or a device that performs angiography by receiving infrared light
- A device for use in security such as a surveillance camera used for crime prevention or a camera used for person authentication
- A device for use in cosmetic purposes such as a skin measuring instrument that photographs skin or a microscope that photographs the scalp
- A device for use in sports such as an action camera or a wearable camera for sports applications and the like
- A device for use in agriculture such as a camera that monitors the condition of fields and crops
Note that the present technology can also be embodied in the following configurations.
(1)
An image sensor including:
a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner;
a seal member applied to a side of the sensor surface of the sensor substrate;
a sealing member bonded to the sensor substrate via the seal member; and
a reinforcing member made of a material having higher rigidity than the seal member and formed on an outer periphery of the seal member to bond the sensor substrate and the sealing member.
(2)
The image sensor according to (1), in which
the seal member is formed to have a smaller area than each of the sensor substrate and the sealing member to be provided with a gap on the outer periphery of the seal member, the sensor substrate and the sealing member facing each other through the gap, and
the reinforcing member is formed to fill the gap.
(3)
The image sensor according to (1), in which
the seal member and the sensor substrate are each formed to have a smaller area than the sealing member to be provided with a difference in level between side surfaces of the seal member and the sensor substrate and a side surface of the sealing member, and
the reinforcing member is formed to fill the difference in level.
(4)
The image sensor according to (1), in which
the sealing member is formed to have a smaller area than each of the seal member and the sensor substrate to be provided with a difference in level between a side surface of the sealing member and side surfaces of the seal member and the sensor substrate, and
the reinforcing member is formed to fill the difference in level.
(5)
The image sensor according to any one of (1) to (4), further including:
a support substrate bonded to a surface of the sensor substrate opposite to a surface to which the sealing member is bonded, in which
the reinforcing member is formed to fill a gap between a mounting substrate to which the support substrate is electrically connected and the support substrate, and to bond the sensor substrate and the sealing member.
(6)
A method of manufacturing an image sensor in which a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner is bonded to a sealing member via a seal member on a side of the sensor surface of the sensor substrate, the method including:
a step of forming, on an outer periphery of the seal member, a reinforcing member made of a material having higher rigidity than the seal member to bond the sensor substrate and the sealing member.
(7)
An electronic apparatus equipped with an image sensor including:
a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner;
a seal member applied to a side of the sensor surface of the sensor substrate;
a sealing member bonded to the sensor substrate via the seal member; and
a reinforcing member made of a material having higher rigidity than the seal member and formed on an outer periphery of the seal member to bond the sensor substrate and the sealing member.
Note that the present embodiment is not limited to the aforementioned embodiment, where various modifications can be made without departing from the scope of the present disclosure.
REFERENCE SIGNS LIST
- 11 Image sensor
- 12 Support substrate
- 13 Sensor substrate
- 14 Sealing resin
- 15 Reinforcing resin
- 16 Sealing glass
- 17-1 and 17-2 Through electrode
- 18 Sensor surface
- 21 Substrate
- 22 Sensor layer
- 23 Support substrate layer
- 24 Resin layer
- 25 Glass layer
- 31 Mounting substrate
- 32-1 and 32-2 Solder
Claims
1. An image sensor comprising:
- a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner;
- a seal member applied to a side of the sensor surface of the sensor substrate;
- a sealing member bonded to the sensor substrate via the seal member; and
- a reinforcing member made of a material having higher rigidity than the seal member and formed on an outer periphery of the seal member to bond the sensor substrate and the sealing member.
2. The image sensor according to claim 1, wherein
- the seal member is formed to have a smaller area than each of the sensor substrate and the sealing member to be provided with a gap on the outer periphery of the seal member, the sensor substrate and the sealing member facing each other through the gap, and
- the reinforcing member is formed to fill the gap.
3. The image sensor according to claim 1, wherein
- the seal member and the sensor substrate are each formed to have a smaller area than the sealing member to be provided with a difference in level between side surfaces of the seal member and the sensor substrate and a side surface of the sealing member, and
- the reinforcing member is formed to fill the difference in level.
4. The image sensor according to claim 1, wherein
- the sealing member is formed to have a smaller area than each of the seal member and the sensor substrate to be provided with a difference in level between a side surface of the sealing member and side surfaces of the seal member and the sensor substrate, and
- the reinforcing member is formed to fill the difference in level.
5. The image sensor according to claim 1, further comprising:
- a support substrate bonded to a surface of the sensor substrate opposite to a surface to which the sealing member is bonded, wherein
- the reinforcing member is formed to fill a gap between a mounting substrate to which the support substrate is electrically connected and the support substrate, and to bond the sensor substrate and the sealing member.
6. A method of manufacturing an image sensor in which a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner is bonded to a sealing member via a seal member on a side of the sensor surface of the sensor substrate, the method comprising:
- a step of forming, on an outer periphery of the seal member, a reinforcing member made of a material having higher rigidity than the seal member to bond the sensor substrate and the sealing member.
7. An electronic apparatus equipped with an image sensor comprising:
- a sensor substrate provided with a sensor surface on which a photodiode is arranged in a planar manner;
- a seal member applied to a side of the sensor surface of the sensor substrate;
- a sealing member bonded to the sensor substrate via the seal member; and
- a reinforcing member made of a material having higher rigidity than the seal member and formed on an outer periphery of the seal member to bond the sensor substrate and the sealing member.
Type: Application
Filed: Jan 29, 2016
Publication Date: Jan 4, 2018
Inventor: HIROSHI ISOBE (KANAGAWA)
Application Number: 15/546,829