JP2010232582A - Image pickup device package and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device package ensuring reliability of products by avoiding hollowing of light transmitting substrates even if metal patterns are formed by print or an environment changes. <P>SOLUTION: The image pickup device package is equipped with: the light-transmitting substrate 2 including a first metal 6; an element mounting substrate 3 including a second metal and mounting an image pickup device 10 connected to the second metal; a conductive joining member 4 for holding the first metal 6 and the second metal at a prescribed interval and electrically connecting the first metal 6 to the second metal in an outside position of the image pickup device 10; and a sealing layer 5 for sealing an image pickup region 11 of the image pickup device 10. A conductive ball 20 is mounted to an extension section 6b of the sealing layer 5 which is usually a non-contact position to an external edge of the sealing layer 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image pickup device package and an image pickup apparatus used for a camera module such as a camera-equipped mobile phone or a digital camera.

  Conventionally, as an imaging device package (also referred to as a light sensing device package or an electronic package) used in a camera module such as a camera-equipped mobile phone or a digital camera, a technique disclosed in Patent Document 1 has been proposed.

  In this method, the translucent substrate and the image sensor (semiconductor chip) are opposed to each other with a gap, a metal pattern is provided on the surface of the translucent substrate, the metal pattern and the image sensor are connected via bumps, The optical substrate and the imaging element are bonded and fixed by a synthetic resin sealing layer provided around the opposing surfaces, and a region surrounded by the sealing layer is a light sensing region (hereinafter referred to as an imaging region). Further, conductive balls as means for mounting on the mother board are connected to the outer end of the metal pattern.

  In the image pickup device package, the metal pattern has a thickness of 1 to 3 μm, and is thus formed by performing sputtering a plurality of times. And when it sputter | spatters, it has a problem that lead time becomes long and manufacturing cost becomes high.

In order to solve this problem, it can be considered that a conductive paste is used, a metal pattern is applied to a light-transmitting substrate by a printing method, and conductive balls are connected.
JP 2002-118207 A

  As described above, it is possible to suppress an increase in manufacturing cost by applying the metal pattern to the translucent substrate by a printing method. However, the conductive paste generally contains silica or the like as a filler. For this reason, when a metal pattern is printed on a translucent substrate made of, for example, a glass substrate via a conductive paste, a part of the filler enters the translucent substrate.

  Then, when the environment changes with the use of the image pickup device package, that is, when the temperature rises or falls, the surface where the filler enters the translucent substrate becomes a boundary surface and the translucent substrate is removed. It has been confirmed that a case of fracture occurs. This is considered to be caused by the fact that when the environment changes, the sealing layer expands and hits the conductive ball (presses the conductive ball). In addition, when the light-transmitting substrate is broken due to environmental changes, the breakage reaches the metal pattern and / or the conductive ball and the metal pattern. As a result, there may be a problem in that the electrical connection with the image sensor becomes poor.

  If the translucent substrate is removed, dust is generated, and the dust may adhere to the imaging region or the lens of the translucent substrate, which reduces the reliability of the product.

  Therefore, the present invention provides an image pickup device package and an image pickup apparatus that can prevent the translucent substrate from being removed even if the metal pattern is formed by printing or the environment changes, and can ensure the reliability of the product. Is an issue.

  An image pickup device package according to the present invention includes a light-transmitting substrate having a first metal patterned by printing formed on a surface thereof, and a second metal patterned to be formed on the surface and electrically connected to the second metal. And the first metal and the second metal at a position outside the image sensor, the element mounting substrate on which the image sensor is mounted, and the first metal and the second metal are kept at a predetermined distance. A plurality of conductive joint members provided so as to electrically connect to each other, and a sealing layer that substantially seals the imaging region of the imaging element in a closed loop shape and includes a resin material, the sealing layer including the first layer An extension portion that fills a cavity in a space portion between one metal and the second metal, and the first metal extends outward with respect to an outer end portion of the sealing layer. And the conductive ball is always non-existent from the outer end of the sealing layer. It is characterized in that in touching a position attached to the extending portion.

  The conductive ball is not always in contact with the outer edge of the sealing layer. Even if the imaging device package changes the environment due to use, that is, the temperature rises or falls, the conductive ball has an outer edge of the sealing layer. Is a meaning that can maintain a non-contact state. According to such a configuration, even when the sealing layer is thermally expanded, the conductive ball is not pushed, and therefore the conductive ball does not move relative to the translucent substrate. Therefore, the electrical connection between the conductive ball and the first metal is not caused. Even if the translucent substrate is a glass substrate, it does not generate glass dust and becomes a highly reliable product.

  In the image pickup device package of the present invention, the first metal is formed in an arc shape whose surface shape is convex toward the device mounting substrate side.

  As in this configuration, the surface shape of the first metal is an arc shape and the corners are eliminated, so that the surface shape of the first metal can be easily maintained and the corners are not lost. Suppressed and highly reliable product.

  In the image pickup device package of the present invention, the first metal has a thickness at the apex of the arc shape set to 3 to 10 μm.

  According to such a configuration, even if the first metal is formed by printing, reliability in terms of the electrical connectivity of the first metal is ensured, and the imaging device package is not hindered in thickness.

  In the image pickup device package of the present invention, a resist layer is overlaid on the surface of the first metal.

  According to such a configuration, since the first metal is protected by the resist layer, the electrical connectivity of the first metal is ensured, and the first metal is prevented from being peeled off and the generation of dust is suppressed. The

  The image pickup apparatus of the present invention is characterized in that any one of the image pickup device packages described above is used.

  According to this configuration, even if the sealing layer is thermally expanded, the conductive ball is not pushed, and therefore the conductive ball does not move with respect to the translucent substrate. Therefore, the conductive ball, the first metal, and the imaging device Thus, even if the light-transmitting substrate is a glass substrate, it does not generate glass dust and becomes a highly reliable product.

  According to the image pickup device package and the image pickup apparatus of the present invention, even when the environment changes, the state in which the conductive ball and the outer end portion of the sealing layer are not in contact is maintained, and the sealing layer pushes the conductive ball. Since the conductive ball does not move relative to the translucent substrate, the electrical connection state between the conductive ball, the first metal, and the imaging element can be ensured satisfactorily. Even if it is a glass substrate, there is an excellent effect that it becomes a highly reliable product without generating glass dust.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a configuration of an image pickup apparatus including an image pickup device package, and FIG. 2 is a schematic diagram for explaining an arcuate cross section and a contact angle.

  As shown in FIGS. 1 and 2, the imaging apparatus 1 according to the present embodiment includes an imaging element package 1A and a lens unit 1B.

  The image pickup device package 1A is attached to one end side of the lens unit 1B in the image pickup apparatus 1. The imaging element package 1 </ b> A includes a translucent substrate 2, an element mounting substrate 3, a conductive bonding member 4, and a sealing layer 5.

  The translucent substrate 2 is a glass substrate, and a patterned first metal (wiring layer) 6 is formed on the surface 7. In this case, the first metal 6 is formed by printing and is formed in a layer having substantially the same thickness in the inner and outer directions. The first metal 6 is formed by printing a conductive paste on the translucent substrate 2. As the conductive paste, silica, that is, fine silicon dioxide, is contained as a filler. Part of the filler penetrates into the translucent substrate 2, and the first metal 6 is reliably patterned on the translucent substrate 2. ing.

Further, a resist layer 8 is formed on the surface 7 of the translucent substrate 2 so as to cover the inner portion of the first metal 6 including at least the inner end face 6a. The resist layer 8 is also called a passivation layer, and is a layer formed to protect the surface of the first metal 6 from external damage after the wiring process is completed.
Mounted on the element mounting substrate 3 is an image sensor (light sensing portion) 10 in which a patterned second metal (not shown wiring layer) is formed on the surface 9 and electrically connected to the second metal. Has been. The predetermined distance L between the surface 9 of the element mounting substrate 3 and the surface of the first metal 6 is set in a range of 15 μm to 80 μm.
In this embodiment, the image sensor 10 is separately mounted on the element mounting board 3, but the image sensor 10 and the element mounting board 3 may be integrally formed. Further, since the thickness t of the first metal 6 is 3 to 10 μm, the distance between the surface 7 of the translucent substrate 2 and the surface 9 of the element mounting substrate 3 is 18 μm to 90 μm. Substantial effects are the same as when the predetermined distance L is set to 15 μm to 80 μm.

  The conductive bonding member 4 maintains the predetermined distance L between the first metal 6 and the second metal, and electrically connects the first metal 6 and the second metal at a position outside the image sensor 10. A plurality of them are provided. The conductive bonding member 4 is formed by bonding gold bumps or solder bumps with solder or a conductive adhesive.

  The sealing layer 5 substantially seals the imaging region 11 of the imaging device 10 in a closed loop shape when seen in a plan view, and includes a resin material (in this case, contains an epoxy resin). Yes. Further, the sealing layer 5 maintains the relationship between the translucent substrate 2 and the element mounting substrate 3 so that the first metal 6 and the second metal secure a predetermined distance L. The element mounting substrate 3 is adhered so as to be attached to each other.

  The resist layer 8 includes the first resist layer 13 on the inner side (image sensor 10 side) from the conductive bonding member 4 and the second resist on the outer side from the conductive bonding member 4 with the conductive bonding member 4 interposed therebetween. Each of the layers 14 is arranged. The first resist layer 13 and the second resist layer 14 cover the outer peripheral surface of the first metal 6, and the conductive bonding member 4 of the first resist layer 13 and the second resist layer 14. Are arranged so that the end face facing the electrode is close to the conductive bonding member 4.

  The sealing layer 5 substantially surrounds the plurality of conductive joining members 4 at a position outside the image sensor 10 and fills the cavity 15 in the space between the first metal 6 and the second metal. ing. As for the cross section of the sealing layer 5, the entire inner end surface 16 that is the end surface on the imaging region side is formed in a fillet shape. The outer end surface 17 of the sealing layer 5 is formed as an inclined surface (tapered surface) from the side surface 18 of the element mounting substrate 3 toward the surface of the second resist layer 14.

As shown in FIG. 2, in the inner end face 16 of the sealing layer 5, the central portion in the thickness direction is an arcuate cross-sectional portion 19 that is concave outward. In the figure, a virtual circle 19a in contact with the arcuate cross section 19 is indicated by a virtual line. The center of the virtual circle 19a is preferably substantially at the center in the thickness direction of the sealing layer 5 from the viewpoint of improving the bonding strength at the contact portion between the sealing layer 5 and the substrates 2 and 3. If the arcuate cross section 19 is a fillet shape, even if the center of the imaginary circle 19a moves in the thickness direction of the sealing layer 5, the bonding strength can be improved as compared with a non-fillet shape.
The translucent substrate 2 side end portion 19b and the element mounting substrate 3 side end portion 19c with respect to the arcuate cross section 19 extend inward with respect to the arcuate cross section 19, and are formed in a curved shape as the entire inner end face 16. Has been. Although the arcuate cross section 19 is positioned between the translucent substrate 2 and the element mounting substrate 3 in the present embodiment, the present invention is not limited to this, and as shown in FIG. It may be located in a region between the first resist layer 13 and the element mounting substrate 3.

  In the sealing layer 5, the radius of the arc of the arc-shaped cross section 19 is set in the range of 3 to 20 μm. As shown in FIG. 2 (or FIG. 3), the respective contact angles θ1, 1 at the contact portions of the translucent substrate 2 (or translucent substrate 2 side) and the element mounting substrate 3 in the fillet-shaped portion of the sealing layer 5 are shown. θ2 is set to 75 to 5 °, preferably 30 to 10 °.

  Returning to FIG. 1, the image pickup device package 1 </ b> A includes a conductive ball 20 (in this case, a solder ball is used). The conductive ball 20 is connected to the surface of the extended portion 6 b that extends toward the outer end side of the surface 7 of the translucent substrate 2 among the first metal 6. It electrically connects to a wiring (land) (not shown) provided on the surface of the wiring substrate 7A (for example, a flexible substrate).

  The extending portion 6 b is a portion extending further outward with respect to the outer end surface 17 (corresponding to the outer end portion) of the sealing layer 5, and the conductive ball 20 is formed on the outer side of the sealing layer 5. The end face 17 is fixed by being electrically connected to the extending portion 6b at a position that is always in non-contact. In this case, “non-contact always” means that the outer end surface 17 of the sealing layer 5 can be maintained in a non-contact state with the conductive ball 20 even when the environment of the image pickup device package 1A is changed, that is, there is a temperature rise. It is.

  The lens unit 1B includes a main body 21 integrated with the image pickup device package 1A, a lens barrel 22 disposed on the inner side of the main body 21, and a lens holder 23 attached to the inner side of the lens barrel 22 via, for example, a plurality of lenses. The three (three) lenses 24, 25, and 26 and an infrared cut filter 27 disposed in front of the imaging surface of the imaging device 10 are provided.

  The light (image) transmitted through the lenses 24, 25, and 26 passes through the infrared cut filter 27 and the element mounting substrate 3 in this order, and is guided to the image sensor 10.

  In the image pickup device package 1A having the above-described configuration, the fillet shape of the inner end face 16 of the sealing layer 5 is the light transmitting substrate 2 (or the resist layer 8) and the material or surface roughness of the device mounting substrate 3, the light transmitting substrate 2 ( Alternatively, the resist layer 8) and the element mounting substrate 3 can be formed into a required shape by adjusting the dimensions (corresponding to the thickness of the sealing layer 5), the viscosity of the sealing layer 5, and the like. In addition, as resin used for the sealing layer 5, the above-mentioned epoxy resin and phenol resin are used suitably. In order to reduce the linear expansion coefficient of these resins, silica may be added as a filler as necessary.

  By setting the contact angles θ1 and θ2 as indices representing the wettability on the light-transmitting substrate 2 side (or the resist layer 8 side) and the element mounting substrate 3 side in the fillet-shaped portion of the sealing layer 5 to the above angles, The bonding strength at the contact portion with the sealing layer 5 can be increased to 1.2 times or more compared to the case where the sealing layer 5 is not in a fillet shape.

  Therefore, even if there is an environmental change in which the imaging device package 1A is used in the imaging device 1 and the imaging device package 1A is heated by using the imaging device package 1A, electrical connection between the first metal 6 and the second metal is performed. It can be stabilized. For this reason, it is possible to improve the reliability of the image pickup device package 1A as a product and eventually the image pickup apparatus 1 over a long period of time.

  Further, a predetermined distance L between the surface 9 of the element mounting substrate 3 and the surface of the first metal 6 is set in a range of 15 μm to 80 μm, and the arc radius of the arcuate cross section 19 is set to 3 to 3 in the sealing layer 5. The range is set to 20 μm. With this configuration, it is possible to further improve the bonding strength at the contact portion between the sealing layer 5 and the substrates 2 and 3 while realizing a reduction in the height of the imaging element package 1A and thus the imaging device 1.

  Further, the conductive ball 20 is electrically connected and fixed to the extending portion 6b at a position that is always in non-contact with the outer end surface 17 of the sealing layer 5. With this configuration, even when the temperature of the image pickup device package 1 </ b> A increases due to use, the outer end surface 17 of the sealing layer 5 is not in contact with the conductive ball 20. That is, even if the temperature rises and the sealing layer 5 expands outward, the sealing layer 5 does not push the conductive ball 20, and the conductive ball 20 can move in a predetermined position on the extending portion 6b. Absent. That is, the first metal 6 to which the conductive balls 20 are fixed is formed by printing the conductive paste on the light-transmitting substrate 2, and a part of the filler of the conductive paste is formed on the light-transmitting substrate 2. Even if it has penetrated, the portion where the filler has entered becomes a boundary surface, and the translucent substrate 2 is not removed, and the first metal 6 to which the conductive ball 20 is fixed is translucent. It is possible to avoid peeling from the conductive substrate 2.

  As a result, even if the translucent substrate 2 is a glass substrate, it does not generate glass dust, and the electrical connection state between the conductive ball 20 and the first metal 6 is good. It is possible to secure a highly reliable product.

  The outer end surface 17 of the sealing layer 5 is formed as an inclined surface that extends from the side surface 18 of the element mounting substrate 3 toward the surface of the second resist layer 14. For this reason, even if the temperature rises and the sealing layer 5 expands outward, the outer diameter surface of the spherical conductive ball 20 is more unlikely to contact the outer end surface 17 of the sealing layer 5. The inclined surface from the side surface 18 of the element mounting substrate 3 toward the surface of the second resist layer 14 may be a fillet-shaped inclined surface.

The present invention is not limited to the above embodiment. That is, as shown in FIG. 4, the inner end surface 16 may have a fillet shape in which the translucent substrate 2 side end 19b and the element mounting substrate 3 side end 19c are displaced. In the example of the figure, the element mounting substrate 3 side end portion 19c is further displaced inward relative to the translucent substrate 2 side end portion 19b. In the inner end face 16 of the sealing layer 5, the central portion in the thickness direction is an arcuate cross-sectional portion 19 that is concave outward. In FIG. 4, a virtual circle 19 a in contact with the arcuate cross section 19 is indicated by a virtual line. The center of the virtual circle 19a is slightly displaced toward the translucent substrate 2 with respect to the center of the sealing layer 5 in the thickness direction.
Even in the inner end face 16 having such a shape, the contact angles θ1 and θ2 are set in the same angle range as in the above embodiments. Also in this configuration, it is possible to improve the bonding strength at the contact portion between the sealing layer 5 and the substrates 2 and 3 after realizing a reduction in the height of the imaging device package 1A and thus the imaging device. Other configurations and operational effects are the same as in the above embodiment.

Furthermore, in each said embodiment, the cross section of the sealing layer 5 formed the whole inner side end surface 16 which is an imaging region side end surface in the fillet shape. However, even if the entire inner end surface 16 is not formed into a fillet shape, even if a part of the inner end surface 16 is formed into a fillet shape, the bonding strength at the contact portion between the sealing layer 5 and the substrates 2 and 3 is improved accordingly. Can be made.
In addition, as shown in FIG. 5, the first metal 6 may be formed in an arc shape whose surface shape is convex toward the element mounting substrate 3 side. In this case, almost the entire first metal 6 (the portion excluding the conductive bonding member 4) is covered with the resist layer 8 to be protected. As in this configuration, the surface shape of the first metal 6 is made arcuate and the corners are eliminated, so that the surface shape of the first metal 6 can be easily maintained and the corners are not lost. Occurrence is suppressed and the product is highly reliable.

  And it is suitable for the 1st metal 6 that the thickness t in the vertex of circular arc shape is set to 3-10 micrometers, Preferably it is 4-8 micrometers. According to such a configuration, even if the first metal 6 is formed by printing, the reliability in terms of the electrical connectivity of the first metal 6 is ensured, and the thinning of the imaging device package 1A is hindered. Not.

  In the image pickup device package and the image pickup apparatus using the same according to the present invention, the first metal has an extending portion extending outward with respect to the outer end portion of the sealing layer, and the conductive ball has The structure in which the conductive ball and the first metal are well connected can be ensured by the configuration in which the extended portion is attached to the outer end of the sealing layer at a position that is always in non-contact. Even if the translucent substrate is a glass substrate, it can be used to produce a highly reliable product without generating glass dust and a mobile phone with a camera function, a digital camera It is useful in the field of camera modules such as surveillance cameras and in-vehicle cameras.

Sectional drawing which showed the whole structure of the image pick-up element package which shows embodiment of this invention Similarly, an enlarged cross-sectional view showing the fillet shape of the sealing layer The expanded sectional view which shows the fillet shape of the sealing layer of other 2nd Embodiment The expanded sectional view which shows the fillet shape of the sealing layer of other 3rd Embodiment The expanded sectional view showing the 1st metal of other embodiments

DESCRIPTION OF SYMBOLS 1 Image pick-up device 1A Image pick-up element package 2 Translucent board | substrate 3 Element mounting board | substrate 4 Conductive joining member 5 Sealing layer 6 1st metal 6b Extension part 10 Image pick-up element 11 Image pick-up area 15 Cavity 17 Outer end surface 20 Conductive ball

Claims (5)

A translucent substrate on which a first metal patterned by printing is formed on the surface, and an element on which an image pickup device on which the patterned second metal is formed and electrically connected to the second metal is mounted A mounting substrate, the first metal, and the second metal are provided at a predetermined interval so as to electrically connect the first metal and the second metal at a position outside the imaging device. A plurality of conductive joining members formed, and a sealing layer that substantially seals an imaging region of the imaging element in a closed loop shape and includes a resin material, and the sealing layer includes the first metal and the second metal The space between the metal is filled in a cavity, and the first metal has an extending portion extending outwardly with respect to an outer end portion of the sealing layer, and a conductive ball is formed. The extension portion is attached to the outer end portion of the sealing layer at a position that is always in non-contact. Image sensor package, characterized by being kicked. 2. The image pickup device package according to claim 1, wherein the first metal is formed in an arc shape whose surface shape is convex toward the element mounting substrate side. 3. The image pickup device package according to claim 2, wherein the first metal has a thickness of 3 to 10 μm at an apex of the arc shape. 4. 4. The image pickup device package according to claim 1, wherein a resist layer is superimposed on a surface of the first metal. 5. An image pickup apparatus, wherein the image pickup device package according to claim 1 is used.

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