JP2009164362A - Solid-state imaging device and manufacturing method thereof - Google Patents

Abstract

A solid-state imaging device and a method for manufacturing the solid-state imaging device in which moisture of the outside air does not enter the solid-state imaging device even when external stress such as heat due to soldering is applied.
An image sensor chip is mounted and fixed in a recess provided in a ceramic package. A cover glass 16 is placed on the ceramic package 11 and adhered by an ultraviolet curable adhesive 17 to seal the recess 11 a of the ceramic package 11. The ceramic package 11 is placed on the mounting substrate 20, and the external terminals 21 provided on the ceramic package 11 are soldered to solder lands provided on the mounting substrate 20. A sealing agent 25 a is applied to a range from the peripheral edge portion 16 a of the cover glass 16 to the mounting substrate 20 excluding the transmission light transmission range 26 of the image sensor chip 12. The sealing agent 25 a is cured to form a moisture-proof sealing member 25 and seals the outer edge portion 17 a of the adhesive 17.
[Selection] Figure 2

Description

  The present invention relates to a solid-state imaging device with improved moisture resistance and a method for manufacturing the same.

  There are two types of packages used in solid-state imaging devices: plastic packages and ceramic packages, but plastic packages have the advantage of being easy to mold and easy to achieve dimensional accuracy, but they have poor environmental resistance and have problems with moisture resistance. Ceramic packages are frequently used for high-density solid-state imaging devices with high density. These solid-state imaging devices must protect the image sensor chip from the humidity of the outside air with a simple structure.

  Patent Document 1 below describes a hollow package for a solid-state imaging device in which a plastic package is wrapped with a coating material having low moisture permeability to improve the moisture resistance of the plastic package.

Further, Patent Document 2 below discloses a transparent moisture-proof device in which an integrated light-receiving element mounted on a circuit board is housed in an outer frame, and a light-receiving surface of the integrated light-receiving element exposed to the opening of the outer frame is applied with a transparent adhesive. A highly integrated light receiving device covered with a sheet is shown.
Japanese Patent Laid-Open No. 10-074865 JP 2002-118243 A

  The solid-state imaging device using the ceramic package is made so that the inside is sealed by adhering a cover glass to the ceramic package on which the image sensor chip is placed as compared with the one shown in the above patent document. Therefore, it is excellent in environmental resistance including moisture resistance.

  However, the adhesive that bonds the ceramic package and the cover glass is often an epoxy resin type, and cracks enter the adhesive that has hardened due to thermal expansion due to soldering during board mounting or distortion caused by other factors, The moisture-proof performance may deteriorate and external moisture may enter the solid-state imaging device. In particular, lead-free solder that has recently been used due to environmental problems has a high mounting temperature and a large thermal stress on the package, and thus has a great influence on the adhesive.

  Further, in the configuration in which the light receiving element receives light transmitted through the transparent adhesive as in Patent Document 2 described above, the sensitivity is lowered by the transparent adhesive. Furthermore, the dispersion of light may occur due to the transparent sheet or the adhesive, which causes a deterioration in the performance of the light receiving element.

  In view of the above problems, the present invention proposes a solid-state imaging device and a method for manufacturing the same, in which moisture of outside air does not enter the solid-state imaging device even when an external stress such as heat caused by soldering is applied.

  A solid-state imaging device according to the present invention includes an image sensor chip, a ceramic package having a recess on which the image sensor chip is placed, a cover glass that covers the recess and encloses the image sensor chip in the ceramic package, the cover glass, An adhesive that adheres the ceramic package and seals the recess; and a moisture-proof seal member that covers an outer edge of the adhesive that is exposed between the cover glass and the ceramic package. Lead terminals provided on the ceramic package are soldered to solder lands on the mounting board.

  The moisture-proof seal member is applied so as to cover the cover glass except the transmission range of the received light of the image sensor chip and to cover the entire side surface of the ceramic package from the cover glass to the mounting substrate. It is a silicone-based, rubber-based, or elastomer-based thermosetting sealant, and after curing, it has flexibility, low moisture permeability, and high airtightness.

  In the solid-state imaging device, the image sensor chip is placed in the ceramic package by adhering the first step of placing the image sensor chip in the recess provided in the ceramic package, and the cover glass covering the recess and the ceramic package. A second step of hermetically sealing, a third step of placing the ceramic package on the mounting substrate and soldering lead terminals provided on the ceramic package to solder lands provided on the mounting substrate, and light reception of the image sensor chip A moisture-proof seal member covers a peripheral portion of the cover glass excluding a light transmission range, an outer edge portion of the adhesive exposed between the cover glass and the ceramic package, and a side surface portion of the ceramic package. And is manufactured by a process.

  In the solid-state imaging device according to the present invention, the outside of the adhesive bonded with the ceramic package and the cover glass is covered with the moisture-proof sealing member. Therefore, even if the moisture-proof performance of the adhesive is lowered, the moisture of the outside air does not enter the inside. The performance of the image sensor chip can be maintained for a long time.

  Further, since the moisture-proof seal member covers the cover glass except for the transmission range of the received light of the image sensor chip, it does not adversely affect the received light of the image sensor chip.

  As shown in FIGS. 1 and 2, in the solid-state imaging device 10, the image sensor chip 12 is placed and fixed in a recess 11 a provided in the ceramic package 11. The bonding pads 13 of the fixed image sensor chip 12 and the internal terminals 14 of the ceramic package 11 are connected by a thin metal wire 15.

  A cover glass 16 is placed on the ceramic package 11 so as to cover the recess 11a. The cover glass 16 is coated with an adhesive 17 of an ultraviolet curable resin between the ceramic package 11 and seals the concave portion 11 a in which the image sensor chip 12 is accommodated.

  The ceramic package 11 is placed on the mounting substrate 20, and external terminals (lead terminals) 21 provided on the ceramic package 11 are soldered to solder lands 22 provided on the mounting substrate 20. The external terminal 21 is electrically connected to the internal terminal 14.

  A sealant 25a is applied from the cover glass 16 to the mounting substrate 20, and after application, the sealant 25a is cured and solidified by overheating to form the moisture-proof seal member 25. The moisture-proof seal member 25 is applied and formed so as to cover the cover glass 16 except the range 26 through which the light received by the image sensor chip 12 is transmitted and to cover the entire circumference of the side surface 11b of the ceramic package 11 reaching the mounting substrate 20. The outer edge portion 17a of the adhesive 17 exposed between the cover glass 16 and the ceramic package 11 is covered.

  The moisture-proof seal member is applied and cured so as to cover the cover glass except the transmission range of received light of the image sensor chip and to cover the entire side surface of the ceramic package from the cover glass to the mounting substrate. After that, it has flexibility, low moisture permeability, and high airtightness.

  Next, a manufacturing method of the solid-state imaging device 10 will be described along the flowchart shown in FIG. In the first step, as shown in FIGS. 4 and 5, the image sensor chip 12 is placed and fixed in the recess 11 a provided in the ceramic package 11. The bonding pads 13 of the fixed image sensor chip 12 and the corresponding internal terminals 14 of the ceramic package 11 are connected by a thin metal wire 15.

  In the second step, as shown in FIGS. 6 and 7, the adhesive 17 of the ultraviolet curable resin is applied to the place where the cover glass 16 of the ceramic package 11 is placed, and the cover glass 16 is placed and the ceramic package is placed. 11 recesses 11a are sealed.

  In the third step, as shown in FIGS. 8 and 9, the ceramic package 11 is placed on the mounting substrate 20 and the external terminals (lead terminals) 21 provided on the ceramic package 11 are soldered on the mounting substrate 20. Solder to the land 22.

  In the fourth step, as shown in FIG. 10, the mask plate 28 is placed on the cover glass 16 so that the range 26 through which the light received by the image sensor chip 12 is transmitted is hidden. Next, as shown in FIG. 11, a sealant 25 a is applied from the peripheral edge portion 16 a of the cover glass 16 exposed around the mask plate 28 to the mounting substrate 20. The sealing agent 25 a covers the outer edge portion 17 a of the adhesive 17 exposed between the cover glass 16 and the ceramic package 11 and the side surface 11 b of the ceramic package 11. Thereafter, it is heated and cured to form the moisture-proof seal member 25. As shown in FIG. 12, the solid-state imaging device 10 is completed by removing the mask plate 28 from the cover glass 16.

  The solid-state imaging device 10 configured and manufactured as described above can be used even when the adhesive 17 is cracked due to stress or deterioration with time during the soldering operation in the first step and the third step described above. Since the moisture-proof seal member 25 is formed on the outside, the humidity of the outside air does not enter the recess 11 a of the ceramic package 11. Therefore, since the image sensor chip 12 sealed in the recess 11a does not deteriorate due to humidity, the high quality and high performance of the solid-state imaging device 10 can be maintained for a long time.

It is the figure which looked at the solid-state imaging device by this invention from the top. It is sectional drawing of FIG. It is a flowchart which shows the manufacturing method of a solid-state imaging device. FIG. 6 is a top view of the first step of the manufacturing method. It is sectional drawing of FIG. It is a top view of the 2nd process of a manufacturing method. It is sectional drawing of FIG. It is a top view of the 3rd process of a manufacturing method. It is sectional drawing of FIG. It is the figure which mounted the mask board. It is sectional drawing of the 4th process of a manufacturing method. It is a figure which removes a mask board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Solid-state imaging device 11 Ceramic package 11a Recessed part 11b Side part 12 Image sensor chip 13 Bonding pad 14 Internal terminal 15 Metal fine wire 16 Cover glass 16a Peripheral part 17 Adhesive 17a Outer edge part 20 Mounting board 21 External terminal (lead terminal)
22 Solder land 25 Moisture-proof seal member 25a Sealant 26 Range through which received light is transmitted 28 Mask plate

Claims (4)

In a solid-state imaging device equipped with an image sensor chip,
A ceramic package having a recess in which the image sensor chip is placed;
A cover glass that covers the recess and encloses the image sensor chip in the ceramic package;
An adhesive that bonds the cover glass and the ceramic package and seals the recesses in an airtight manner;
The peripheral portion of the cover glass excluding the transmission range of the received light of the image sensor chip, the outer edge portion of the adhesive exposed between the cover glass and the ceramic package, and the side portion of the ceramic package; A moisture-proof seal member covering the
A solid-state imaging device comprising:   The solid-state imaging device has a mounting substrate provided with a solder land to which a lead terminal provided in the ceramic package is soldered, and the lead terminal is soldered to the solder land. Item 2. The solid-state imaging device according to Item 1.   3. The moisture-proof seal member is formed by applying a silicone-based, rubber-based, or elastomer-based thermosetting sealant having flexibility, low moisture permeability, and high airtightness. Solid-state imaging device. In a method for manufacturing a solid-state imaging device equipped with an image sensor chip,
A first step of placing the image sensor chip in a recess provided in a ceramic package;
A second step of adhering the image sensor chip into the ceramic package by bonding the cover glass covering the recess and the ceramic package with an adhesive;
A third step of placing the ceramic package on a mounting substrate and soldering a lead terminal provided on the ceramic package to a solder land provided on the mounting substrate;
The peripheral portion of the cover glass excluding the transmission range of the received light of the image sensor chip, the outer edge portion of the adhesive exposed between the cover glass and the ceramic package, and the side portion of the ceramic package; A fourth step of covering with a moisture-proof seal member;
A method for manufacturing a solid-state imaging device, comprising:

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