JP2010153763A - Package for storing imaging element and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for storing imaging element and an imaging device having a high reliability even when the width of a lead terminal and the mutual distance between the lead terminals are getting smaller, and to provide an imaging device. <P>SOLUTION: The package for storing imaging element includes, a base body 1 having a mounting part 1a for an imaging element 9 in the center of the upper surface, a plurality of circuit conductor 2 arranged from the mounting part 1a of the upper surface to the outer circumference of the base body 1, a plurality of lead terminals 3 connected to each of the plurality of circuit conductors 2 and extending outward of the base body 1, a frame 6 facing opposite to the base body 1 surrounding the mounting part 1a from the junction part of the circuit conductor 2 and the lead terminal 3 to the outer circumference, and a joining material 5 filling a space between the frame 6 and the base body 1, wherein there exist a portion 3a in the lend terminal 3 whose height of the bottom face increases from outside of the junction part to the outer circumference of the base body 1. The fixation of the lead terminal 3 to the base body 1 is strengthened and the junction reliability and air tightness reliability of the lead terminal 3 become higher by the infiltration of the joining material 5 to the underside of the lead terminal 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor housing package having a lead terminal for housing an image sensor such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor) and an image pickup apparatus using the same. is there.

  In recent years, in a digital camera equipped with an imaging device using an imaging device such as a CCD or CMOS, the image quality is improved by increasing the number of pixels and reducing noise by increasing the size of the imaging device. .

  In order to improve the image quality of the image pickup apparatus, it is effective to reduce noise by strengthening the ground of an image pickup device storage package (hereinafter also simply referred to as a package). In order to strengthen the ground of the package, it is necessary to increase the number of terminals connected to the ground of the image sensor, resulting in an increase in the number of lead terminals of the package.

  There is a so-called sardip type package in which a plurality of lead terminals are bonded to a ceramic substrate with an image sensor mounting portion interposed therebetween as an image sensor storage package. The imaging element mounted on the mounting unit and the lead terminal are connected by wire bonding. Lead terminals are manufactured by pressing a metal plate or etching it to produce a lead frame in which a plurality of lead terminals are connected by a frame, and then joining the lead frame and the substrate together with a bonding material such as glass. The In order to give the necessary strength to the side connected to the external conductor of the lead terminal, the thickness of the lead terminal, that is, the thickness of the lead frame must be about 0.25 mm.

  However, when the number of lead terminals increases, the distance between the tips of the lead terminals connected to the wire bonding, which is close to the image sensor, must be reduced. When the distance is smaller than 0.25 mm, the thickness is about 0.25 mm. It becomes difficult to produce a lead frame by pressing or etching a metal plate.

  Therefore, as shown in a cross-sectional view in FIG. 10, a circuit conductor 22 is formed on the upper surface of the base 21 by printing or the like, and a lead terminal 23 is joined to the circuit conductor 22 by pressure bonding or the like. The circuit conductor 22 is imaged by using a lead frame having a large interval between the lead terminals 23 by setting the interval close to the mounting portion 21a of the imaging element 29 to be small and the interval distant from the mounting portion 21a to be large. An element storage package can be manufactured. The lead terminal 23 is fixed and sealed by a bonding material 25 such as glass for fixing the frame body 26 thereon to the base body 21 to form an image pickup device storage package (see, for example, Patent Document 1). ). Then, the image pickup element 29 is bonded to the mounting portion 21a in the center of the package, the image pickup element 29 and the circuit conductor 22 are connected by the bonding wire 30, and the translucent lid 28 is bonded thereon by the adhesive 27. It becomes an imaging device by hermetically sealing.

Japanese Patent Laid-Open No. 10-50925

  However, the demand for higher image quality has further increased, the number of lead terminals has increased, and when the imaging device has also been miniaturized due to the demand for miniaturization of digital cameras, the width of the lead terminals has decreased, leading to lead terminals and circuit conductors. It is expected that the area of the connecting portion will be reduced and the connection strength will be weakened.

  In addition, the lead terminal is covered with a bonding material such as glass and fixed to the base. The bonding material joins the upper surface and the side surface of the lead terminal and also joins the base surface between the lead terminals so that the lead terminal becomes the base. Therefore, when the distance between the lead terminals is small, the width of the bonding material between the lead terminals is small, and the strength of fixing the lead terminal to the base body by the bonding material around the lead terminals is weak. When the number of lead terminals is small, there is a portion where the lead terminals are not connected to the upper surface of the base, and the bonding material and the base are firmly connected at that portion, and the lead terminals are also firmly connected to the base. However, as the number of lead terminals increases, the portion of the top surface of the base that is not connected to the lead terminals decreases, so that the strength of fixing the lead terminals to the base must be increased even around the lead terminals.

  If the strength of fixing the lead terminal to the substrate is weak, the thermal stress applied to the lead terminal when the image sensor is mounted and mounted on the substrate as an imaging device, or the lead terminal when the imaging device is mounted on a digital camera and used The applied stress makes it easier for the lead terminal to come off the base and the hermetic seal is impaired, and the lead terminal comes off from the base and stress is applied to the connection between the lead terminal and the circuit conductor. The electrical connection with the circuit conductor may be impaired.

  The image pickup device storage package and the image pickup apparatus using the same according to the present invention have been completed in view of the above problems, and the purpose thereof is reliability even if the width of the lead terminals and the interval between the lead terminals are reduced. It is an object of the present invention to provide a high-capacity image pickup device storage package and an image pickup apparatus using the same.

  An image sensor housing package according to the present invention includes a base having an image sensor mounting portion at the center of the upper surface, a plurality of circuit conductors arranged from the mounting portion to the outer periphery of the upper surface of the base, and a plurality of the circuits A plurality of lead terminals each connected to a conductor and extending to the outside of the base; a frame that surrounds the mounting portion and faces the base from the connection portion between the circuit conductor and the lead terminal; In the image pickup device storage package including a bonding material filled between the frame and the base, the lead terminal has a portion whose lower surface is increased from the outside to the outer periphery of the base. It is characterized by this.

  In the above-described configuration, the imaging element storage package of the present invention is characterized in that the thermal expansion coefficient of the bonding material is larger than the thermal expansion coefficient of the lead terminal.

  In the image pickup device storage package according to the present invention, in each of the above configurations, the lead terminal has a quadrangular shape in which a cross section perpendicular to the length direction has rounded corners.

  In the imaging device storage package of the present invention, in each of the above configurations, the lead terminal is at least one of upper and lower surfaces and a side surface from the connection portion between the circuit conductor and the lead terminal to the outer periphery of the base body. It has at least one of a convex part and a recessed part.

  The image pickup device storage package according to the present invention has the same width and thickness as the lead terminal from the inner end of the lead terminal to the inner end of the bonding material. It has an insulating layer having a thermal expansion coefficient substantially the same as the thermal expansion coefficient.

  The imaging device of the present invention is mounted on the imaging element storage package of the present invention having any of the above-described configurations, and is mounted on the mounting portion of the imaging element storage package and is electrically connected to the plurality of lead terminals. An image sensor and a translucent lid bonded to the upper surface of the frame with an adhesive are provided.

  According to the image pickup device storage package of the present invention, since the lead terminal has a portion whose lower surface is higher from the outer side of the connection portion to the outer periphery of the base, the bonding material enters the lower side of the lead terminal, and the lead The entire periphery (upper and lower surfaces and both side surfaces) of the terminal is surrounded by a bonding material, and the bonding material is bonded to the entire surface from the outside to the outer periphery of the connection portion of the base, so that the lead terminal is firmly fixed to the base. Thus, the image pickup element storage package is highly reliable in the connection between the lead terminal and the circuit conductor and the hermetic sealing of the lead terminal.

  Further, according to the image pickup device storage package of the present invention, in the above configuration, when the thermal expansion coefficient of the bonding material is larger than the thermal expansion coefficient of the lead terminal, the sealing material made of glass or the like is heated and melted. When the lead terminal and the frame body are fixed to the base body by cooling and solidifying, the thermal contraction of the joint material surrounding the lead terminal is larger than the thermal contraction of the lead terminal. Since the force that presses the lead terminal acts and the bonding reliability between the lead terminal and the bonding material is improved, the image sensor housing package with higher hermetic reliability is obtained. In addition, since a force acts so that the lead terminal is pressed against the circuit conductor at the joint between the lead terminal and the circuit conductor, the joint strength of the lead terminal is further improved, and the imaging element storage package with higher connection reliability is obtained. .

  Furthermore, according to the image pickup device storage package of the present invention, in the above configuration, when the cross section of the lead terminal is square and the corner has roundness, even if stress is applied between the bonding material and the lead terminal, The part of the bonding material that is in contact with the corner of the lead terminal where the stress is likely to be concentrated is rounded and the stress is dispersed and cracks are suppressed from occurring in the bonding material. It becomes a package for.

  According to the image pickup device storage package of the present invention, in each of the above configurations, the lead terminal protrudes from at least one of the upper and lower surfaces and the side surface from the connection portion between the circuit conductor and the lead terminal to the outer periphery of the base. When it has at least one of a part and a concave part, in addition to increasing the joint area between the joint material and the lead terminal, the convex part or the concave part also becomes a resistance against the force pulling the lead terminal to the outside. Therefore, the image pickup element housing package has higher lead terminal connection reliability and airtight reliability.

  Further, according to the image pickup device storage package of the present invention, in each of the above-described configurations, the lead terminal has the same width and thickness from the inner end of the lead terminal to the inner end of the bonding material. When an insulating layer having a thermal expansion coefficient comparable to that of the thermal expansion coefficient is provided, the thermal expansion of the member located between the frame body and the base body is comparable between the inner side and the outer side of the frame body. In addition, the heat applied to the imaging device is not distorted between the inner side and the outer side of the frame body, and the adhesive reliability and the airtight reliability of the light-transmitting lid bonded on the frame body become higher.

  An image pickup apparatus according to the present invention has an image pickup element storage package configured as described above, an image pickup element that is mounted on a mounting portion and electrically connected to a plurality of lead terminals, and is bonded to an upper surface of a frame with an adhesive. Since the light-transmitting lid is provided, the imaging device has high electrical connection reliability and airtight reliability.

It is sectional drawing which shows an example of embodiment of the imaging device of this invention. It is sectional drawing which expands and shows the A section of FIG. It is sectional drawing which expands and shows the principal part of the other example of embodiment of the imaging device of this invention. It is sectional drawing which expands and shows the principal part of the other example of embodiment of the imaging device of this invention. It is sectional drawing which expands and shows the principal part of the other example of embodiment of the imaging device of this invention. It is sectional drawing which expands and shows the principal part of the other example of embodiment of the imaging device of this invention. It is sectional drawing which shows the cross section cut | disconnected by the AA line of FIG. (A)-(f) is a top view which shows the principal part of the example of embodiment of the imaging device of this invention, respectively. (A) is sectional drawing which shows the principal part of the other example of embodiment of the imaging device of this invention, (b) is a top view. It is sectional drawing which shows an example of embodiment of the conventional imaging device.

  An image sensor storage package and an imaging device of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of an embodiment of an image pickup apparatus of the present invention using an image pickup device storage package of the present invention. FIG. 2 is an enlarged cross-sectional view showing a portion A of FIG. 3 to 6 are enlarged cross-sectional views of main parts of other examples of the image pickup device storage package of the present invention, respectively, similar to FIG. 7 is a cross-sectional view showing a cross section taken along line AA of FIG. FIG. 8A is a plan view showing an example of the main part of FIG. 2, and FIGS. 8B to 8F show the implementation of the imaging apparatus of the present invention using the imaging element storage package of the present invention. It is a top view which shows the principal part of the other example of this form. FIG. 9A is a cross-sectional view showing the main part of another example of the image sensor housing package of the present invention, and FIG. 9B is a plan view. In FIG. 8 and FIG. 9B, the bonding material 5, the frame body 6, the adhesive 7, and the translucent lid 8 are omitted in order to make the shape of the lead terminal 3 and the like easier to understand. 1 to 9, 1 is a base, 1 a is a mounting portion on the upper surface of the base 1, 2 is a circuit conductor, 3 is a lead terminal, 3 a is a portion where the lower surface of the lead terminal 3 is raised, 4 is a connecting material, 5 is a bonding material, 6 is a frame, 7 is an adhesive, 8 is a light-transmitting lid, 9 is an image sensor, 10 is a bonding wire, and 11 is an insulating layer.

  The tip of the lead terminal 3 is connected to each of the plurality of circuit conductors 2 arranged on the upper surface of the base 1, and the bonding material 5 is filled between the frame body 6 and the base 1 on the lead terminal 3. Is an image sensor housing package that is airtightly fixed to the substrate 1. In addition, the image pickup device 9 is mounted on the mounting portion 1a at the center of the upper surface of the base 1, and the image pickup device 9 and the circuit conductor 2 are connected by the bonding wire 10 to be electrically connected to the lead terminal 3, thereby transmitting the light. An image pickup apparatus is obtained by airtightly bonding the adhesive lid 8 to the upper surface of the frame body 6 with the adhesive 7.

  As shown in the examples shown in FIGS. 1 to 7, the image pickup device storage package of the present invention has a base 1 having a mounting portion 1 a for the image pickup device 9 at the center of the upper surface, and an outer periphery from the mounting portion 1 a on the upper surface of the base 1. A plurality of circuit conductors 2 arranged over the portion, a plurality of lead terminals 3 connected to the plurality of circuit conductors 2 and extending to the outside of the base 1, and the circuit conductors 2 and the lead terminals 3 surrounding the mounting portion 1a. In the imaging element storage package, the lead terminal 3 is provided with a frame body 6 facing the base body 1 from the connecting portion to the outer periphery, and a bonding material 5 filled between the frame body 6 and the base body 1. There is a portion 3a having a lower surface from the outside to the outer periphery of the base body 1 from the connection portion. Since the lead terminal 3 has a portion 3 a whose lower surface is higher from the outside of the connection portion to the outer periphery of the base body 1, the bonding material 5 enters the lower side of the lead terminal 3, so that the entire circumference of the lead terminal 3 (upper The lower surface and both side surfaces) are surrounded by the bonding material 5, and the bonding material 5 is bonded to the entire surface from the outer side to the outer periphery of the connection portion of the base body 1, so that the lead terminal 3 is firmly fixed to the base body 1. The imaging element housing package is highly reliable for the connection between the lead terminal 3 and the circuit conductor 2 and the hermetic sealing of the lead terminal 3.

  Further, in the image pickup device storage package of the present invention, in the above configuration, it is preferable that the thermal expansion coefficient of the bonding material 5 is larger than the thermal expansion coefficient of the lead terminal 3. Due to such a configuration, the lead terminal 3 when the lead terminal 3 and the frame body 6 are fixed to the base body 1 by heating and melting the sealing material 7 made of glass or the like and then cooling and solidifying it. Since the heat shrinkage of the bonding material 5 that surrounds the lead terminal 3 around the entire circumference is larger than the heat shrinkage, the force that the bonding material 5 presses the lead terminal 3 works, and the lead terminal 3 and the bonding material 5 Since the bonding reliability of the image pickup device is improved, an image sensor housing package with higher airtight reliability is obtained. In addition, since a force acts so that the lead terminal 3 is pressed against the circuit conductor 2 at the joint portion between the lead terminal 3 and the circuit conductor 2, the joint strength of the lead terminal 3 is further improved, and the image pickup device is housed with higher connection reliability. It becomes a package for.

  Furthermore, in the imaging device storage package of the present invention, in the above configuration, the lead terminal 3 preferably has a square cross section and rounded corners. Therefore, even if a stress is applied between the bonding material 5 and the lead terminal 3, the portion of the bonding material 5 that is in contact with the corner of the lead terminal 3 and tends to concentrate stress is rounded and the stress is dispersed. As a result, the occurrence of cracks in the bonding material 5 can be suppressed, so that an image sensor housing package with higher airtight reliability can be obtained. When a so-called lead frame is manufactured and joined to the substrate 1 and then divided into a plurality of lead terminals 3, the metal plate is punched or etched with a metal mold if the cross-section is rectangular. Can be easily formed. Further, if the cross section of the lead terminal 3 is a horizontally long quadrilateral, the lead terminal 3 is correctly deformed less easily in the width direction of the lead terminal 3 when the lead terminal 3 is bent into a crank shape and molded into a gull wing shape for surface mounting, for example. Since it is easy to mold with the pitch dimension, the distance between the outer end portions of the lead terminal 3 becomes small and short-circuits, or the outer end portion of the lead terminal 3 deviates from the pitch of the circuit board for mounting and cannot be connected. Therefore, the image pickup device storage package is easy to mount.

  In the image pickup device storage package according to the present invention, the lead terminal 3 is connected to the circuit conductor 2 in the above-described configurations as in the examples shown in FIGS. 4, 6, and 8 (b) to 8 (f). It is preferable to have at least one of a convex portion and a concave portion on at least one of the upper and lower surfaces and the side surface from the connection portion with the lead terminal 3 to the outer periphery of the base 1. In this case, in addition to an increase in the bonding area between the bonding material 5 and the lead terminal 3, the convex portion and the concave portion become a resistance against the force of pulling the lead terminal 3 outward, and the lead terminal 3 and the bonding material 5. Therefore, the image pickup element housing package having higher connection reliability and airtight reliability of the lead terminals 3 can be obtained.

  Further, the image pickup device storage package of the present invention is the same as the lead terminal 3 in each of the above configurations from the inner end of the lead terminal 3 to the inner end of the bonding material 5 as in the example shown in FIG. It is preferable to have an insulating layer having the same thermal expansion coefficient as that of the lead terminal 3 in terms of width and thickness. In this case, between the frame body 6 and the base body 1, the thermal expansion of the members located between the frame body 6 and the base body 1 is approximately the same between the inner side and the outer side of the frame body 6. The inner and outer sides of the body 6 are not distorted, and the adhesive reliability and the airtight reliability of the translucent lid 8 adhered on the body 6 are higher. Further, since the translucent lid 8 is not distorted, in particular, when an optical filter is formed on the translucent lid 8, its function is not impaired, so that a higher-performance imaging device is obtained. be able to.

  The substrate 1 is made of a ceramic such as an aluminum oxide sintered body (alumina ceramic), a mullite sintered body, a steatite sintered body, an aluminum nitride sintered body, or the like.

  The substrate 1 can be manufactured as follows. For example, if the substrate 1 is made of an aluminum oxide sintered body, first, an appropriate organic binder, solvent, plasticizer, and dispersant are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. Then, a slurry is made, and this slurry is granulated using a conventionally known spray drying method. Next, this granule is press-molded with a press mold of a predetermined shape to produce a production mold body, and the production mold body is fired at a high temperature of about 1500 ° C. to form the substrate 1. Alternatively, a green sheet is produced using the raw material powder, and the green sheet is punched out with a mold or the like to obtain an appropriate size, thereby obtaining a generated shape. A plurality of green sheets may be laminated to a predetermined thickness.

  It is preferable that the surface of the substrate 1 is flattened by lapping or the like so as to have a flatness of 20 μm or less because tilting and distortion are less likely to occur when the image sensor 9 is mounted. If the portion of the outer peripheral portion of the mounting portion 1a facing the frame body 6 is also made flat, the frame body 6 is joined without being inclined, and the translucent lid 8 adhered on the frame body 6 is also attached to the imaging element 9. This is preferable because it does not tilt.

  The circuit conductor 2 is a conductor formed by a thin film method or a thick film method. When forming by the thick film method, for example, a metal paste obtained by adding an organic solvent, a solvent, and, if necessary, a binder such as glass to a metal powder such as tungsten, molybdenum, manganese, silver, or copper. Is deposited on a predetermined position of the substrate 1 in a predetermined pattern shape by a printing method such as a screen printing method, and is baked at 850 ° C. to 1500 ° C. to be baked on the surface of the substrate 1. As described above, when the substrate 1 is formed using a green sheet, a metal paste may be applied to the green sheet and then formed by simultaneous firing with the substrate 1. In this case, nickel, nickel-cobalt alloy, gold or the like is plated on the surface of the circuit conductor 2 in order to improve the wettability of the connecting material 4 and reduce the connection resistance with the lead terminal 3. It is good to make it adhere by. Moreover, when forming by a thin film method, it carries out as follows. First, an adhesion metal layer and a barrier layer are sequentially formed on the entire main surface of the substrate 1 by a thin film forming method such as vapor deposition, sputtering, or ion plating to form a thin film layer. Next, a resist film having an opening that exposes the thin film layer in the shape of the circuit conductor 2 is formed on the thin film layer, and a main conductor layer such as copper or gold is formed on the exposed thin film layer by plating or the like. Form. Then, the resist film is peeled off, and the barrier layer and the adhesion metal layer which are formed on the entire main surface and are not covered with the main conductor layer are removed by etching, so that the circuit conductor 2 is formed on the upper surface of the substrate 1 in the shape of the circuit conductor 2. Is formed. As with the thick film method, nickel, nickel-cobalt alloy, gold or the like may be deposited on the surface of the circuit conductor 2 by a plating method or the like.

  The circuit conductor 2 has a shape extending from the mounting portion 1a to the outer periphery, and is arranged along the outer periphery of the mounting portion 1a. This arrangement may be arranged in accordance with the arrangement of the electrodes of the image pickup device 9. The normal image pickup device 9 has a quadrangular shape in plan view, but it is not necessary to arrange all four sides of the image pickup device 9. It may be arranged along only one side or may be arranged along only one side. Since the lead terminal 3 is connected to the circuit conductor 2, if the base body 1 has a quadrangular shape, the lead terminal 3 may extend from the four sides to the outside of the base body 1 or may extend from two sides.

  The lead terminal 3 is made of a metal such as an Fe—Ni—Co alloy, Fe—Ni alloy, copper (Cu), or copper alloy. From the viewpoint of connection reliability of the lead terminal 3 with the base body 1, it is preferable that the difference between the thermal expansion coefficient of the base body 1 is small and the base body 1 is made of an aluminum oxide sintered body. For example, an Fe-42% Ni alloy is preferable. Nickel plating layer and gold plating layer are formed on the surface of the lead terminal 3 in order to prevent corrosion, improve conductivity, improve the wettability of the connecting material 4 and reduce the connection resistance with the circuit conductor 2. It is good to deposit sequentially.

  The lead terminal 3 forms a lead frame having a shape in which a plurality of lead terminals 3 are expanded so as to extend from the inner periphery of the frame to the inside by punching the plate material made of the metal with a die, After the lead frame is connected to the base body 1, the plurality of lead terminals 3 are obtained by separating the frame. The lead frame can also be manufactured by etching. If a lead frame-shaped resist film is formed on a metal plate and the lead terminal 3 is made of copper, for example, the resist film can be prepared by etching with ferric chloride and then peeling off the resist film.

  The lead terminal 3 has a portion 3a whose bottom surface is high. In the example shown in FIGS. 1 to 6, the lower surface of all the portions outside the connecting portion of the lead terminal 3 is high, but if the bonding material 5 enters between the lower base 1 of the lead terminal 3. Since the lead terminal 3 is firmly fixed to the base body 1, the bottom surface of the portion of the lead terminal 3 extending outside the outer periphery of the base body 1 may be lower.

  The lead terminal 3 has a portion 3a whose bottom surface is high. However, as shown in FIGS. 2 to 4, the lead terminal 3 forms a portion whose bottom surface is high by bending. 5 and FIG. 6, there is a case where a portion having a lower bottom surface is formed by reducing the thickness. In the example shown in FIG. 2, the bending angle is an obtuse angle, whereas in the examples shown in FIGS. 3 and 4, the bending angle is almost a right angle. In such a case, as in the example shown in FIGS. 3 and 4, if the bent corner is rounded, even if stress is applied between the bonding material 5 and the lead terminal 3, the bonding material 5 This is preferable because the portion where the stress tends to concentrate in contact with the corner of the bent portion is rounded, the stress is dispersed, and the occurrence of cracks in the bonding material 5 is suppressed. Similarly, it is preferable that the corner between the thick portion and the thin portion of the lead terminal 3 is also rounded as in the example shown in FIG.

  The portion 3a where the lower surface of the lead 3 is raised can be formed by pressing using a die or the like before or after the punching process when the lead terminal 3 is manufactured or simultaneously with the punching process. It can also be formed by etching. For example, in the case of the example shown in FIG. 5, when the lead frame is formed by the above etching, the resist film is peeled off only in a region that becomes a thin portion and further etched, so that the thin portion, that is, the lower surface is formed. A raised portion 3a can be formed. Even if the punching process and the pressing process are combined with the etching process, for example, the lead frame is formed by the punching process, and a part 3a having a lower bottom surface is formed by thinning a part of the thickness by the etching process. Good. In the case where there are convex portions and concave portions on the upper surface and the lower surface of the lead terminal 3, these portions can also be formed simultaneously by pressing or etching. In the case of forming a tapered convex portion as in the example shown in FIG. 6 by etching, when the etching solution is sprayed from above the resist, the metal is etched not only in the depth direction of the resist opening but also in the lateral direction. This phenomenon can occur and can be formed using this phenomenon.

  The lead terminal 3 preferably has a square cross section perpendicular to the length direction and has rounded corners as shown in the example shown in FIG. 7. However, when the lead terminal 3 is manufactured by punching, an acid or alkali is used after the punching. After removing the burrs by etching or the like immersed in the liquid, further etching is added to form a square cross section with rounded corners. When the lead terminal 3 is manufactured by etching, additional etching is performed after the resist film is peeled to form a square cross section with rounded corners.

  The lead terminal 3 is shown in FIGS. 4 and 6 with respect to the cross-sectional shape of the lead terminal 3 in the example shown in FIGS. 2 and 5 and the planar shape of the lead terminal 3 in the example shown in FIG. As in the example shown in FIG. 8B to FIG. 8F, the convex portion and the concave portion are formed on at least one of the upper and lower surfaces and the side surface from the connection portion of the circuit conductor 2 and the lead terminal 3 to the outer periphery of the base body 1. It is preferable to have at least one of the following. 4 and 6 have protrusions and recesses on the upper and lower surfaces of the lead terminal 3, and in the examples shown in FIGS. 8B to 8F, the protrusions and Although it has a recessed part, the lead terminal 3 may have a convex part and a recessed part in both an up-and-down surface and a side surface. 8B and 8C show an example in which the cross-sectional shape is a shape like the example shown in FIG. 2, and FIG. 8D shows the cross-sectional shape in FIG. FIG. 8 (e) and FIG. 8 (f) show an example in which the cross-sectional shape is a shape like the example shown in FIG. The combination of the shape and the planar shape is not limited to these.

  In the example shown in FIG. 4, the lead terminal 3 has a convex portion on the upper surface and the lower surface has a concave portion. In the example shown in FIG. 6, the lead terminal 3 has a convex portion on the upper and lower surfaces. In addition, the lead terminal 3 may have a concave portion on the upper surface, and may have a convex portion on the lower surface, or may have a concave portion on the upper and lower surfaces of the lead terminal 3. Further, only one of the upper and lower surfaces may have a convex portion or a concave portion, or may be a plurality of convex portions or a plurality of concave portions, or has both a convex portion and a concave portion on one side. It may be. These convex portions and concave portions may be formed by etching or pressing. When a lead frame including the lead terminal 3 is manufactured by punching, a die corresponding to the convex portion and the concave portion is used for stamping and pressing, so that the convex portion and the lead terminal 3 are simultaneously formed with the lead frame. A recess can be formed. Alternatively, a punching process may be performed after a concave portion is formed in a portion that becomes the lead terminal 3 by cutting or the like in advance on a metal plate material. As in the example shown in FIG. 4, when producing the lead terminal 3 having the concave portion along the convex portion on the surface (lower surface) facing the surface (upper surface) where the convex portion is formed, press working is used. Can be formed more easily. In the example shown in FIGS. 4 and 6, the cross-sectional shape of the convex portion and the concave portion of the lead terminal 3 is a triangle, but the corner portion is rounded. Thus, in addition to having a convex part or a concave part, even if stress is applied between the bonding material 5 and the lead terminal 3 when the cross-sectional shape thereof is a shape having no corners, the bonding material 5 is preferable because cracks are suppressed from occurring.

In the example shown in FIG. 8B, a convex portion is provided on one side surface of the lead terminal 3, and the convex portion is located at a position facing the convex portion on one side surface of the adjacent lead terminal 3 on the other opposing side surface. It has a recess with the same shape. Thus, the arrangement of the convex portion and the concave portion on the opposite side surfaces of the lead terminal 3 locally reduces the interval between the lead terminals 3 as compared with the case where only the convex portion is formed on one side surface or both side surfaces. Since a convex part can be provided without doing, it is preferable. In the example shown in FIG. 8C, since the recesses are provided so as to face both side surfaces of the lead terminal 3, the bonding material 5 is a portion where the interval between the recesses of the adjacent lead terminals 3 and 3 is widened. This is preferable because it easily passes around the lower surface of the lead terminal 3 and increases the connection reliability and airtight reliability of the lead terminal 3. In this case, in particular, it is preferable that the concave portion has a shape that does not have a corner portion where stress tends to concentrate so that the bending strength of the lead terminal 3 does not decrease. In the example shown in FIG. 8D, the side surface on the tip side from the convex portion and the concave portion is recessed with respect to the example shown in FIG. 8B, and the upper side surface in FIG. The side surface of this is shaped like a protrusion over the tip. According to this, since the length of the tip side is longer than the convex part and the concave part, it is preferable because the joining area between the lead terminal 3 and the joining material 5 can be further increased. Further, when the convex portions are provided so as to face both side surfaces of the lead terminal 3, the interval between the adjacent lead terminals 3 and 3 is locally narrowed, and the bonding material 5 wraps around the lower side of the lead terminal 3. Since it tends to be difficult, as shown in the example shown in FIG. 8E, when the through hole is formed in a portion widened by the opposing convex portion, the bonding material 5 passes through the through hole and the bonding material 5 It is more preferable because it is easy to wrap around the lower surface and at the same time has an effect of increasing the bonding strength between the lead terminal 3 and the bonding material 5 by the through hole. When providing convex portions so as to face both side surfaces of the lead terminal 3, the convex portions on the adjacent side surfaces of the adjacent lead terminals 3 and 3 are not adjacent to each other as in the example shown in FIG. Thus, it is preferable to keep the distance between the lead terminals 3 and 3 as small as possible even locally. In the example shown in FIG. 8F, the convex portions provided on both side surfaces of one lead terminal 3 are provided at opposing positions, but the convex portions on both side surfaces of one lead terminal 3 are not opposed. When provided, the convex portions of the adjacent lead terminals 3 and 3 are not adjacent to each other, and the plurality of lead terminals 3 can have the same shape. Also in such a case, it is preferable to provide a through-hole as in the example shown in FIG. 8 (e) in a portion that is widened by providing a convex portion.
In the example shown in FIGS. 1 to 9, the lead terminal 3 is connected to the circuit conductor 2 by a connecting material 4 at the tip. For example, the lead terminal 3 and the circuit conductor 2 may be directly joined by spot welding without using the connecting material 4. The connection material 4 is, for example, Au 80 mass% -Sn 20 mass% eutectic alloy, Au 88 mass% -Ge 12 mass% eutectic alloy, or the like, or Ag 72 mass% -Cu 28 mass% alloy or Ag 55 mass% -Cu 22 mass%. -A brazing material made of an AgCu alloy such as a Zn17 mass%-Sn5 mass% alloy. For example, when an Au 80 mass% -Sn 20 mass% eutectic alloy is used, a ribbon of Au 80 mass% -Sn 20 mass% eutectic alloy is placed on the circuit conductor 2 of the substrate 1, and the lead terminal 3 is placed thereon. The lead terminal 3 can be connected to the circuit conductor 2 by placing the tip and fixing it with a jig and heating it at a peak temperature of 350 ° C. in a reducing atmosphere. As described above, when a lead frame in which a plurality of lead terminals 3 are connected to a frame and integrated is used, and the tips of the plurality of lead terminals 3 of the lead frame are connected and then the frame portion is separated, a plurality of lead terminals are obtained. 3 and the circuit conductor 2 can be aligned simultaneously, which is preferable. Further, the melting point of the connecting material 4 is increased by adjusting the amount of Au 80 mass% -Sn 20 mass% eutectic alloy and the gold plating thickness of the surface of the circuit conductor 2 to increase the gold content in the connecting material 4 after connection. It can be higher than 280 ° C., which is the melting point of the eutectic alloy. For example, when the gold plating thickness of the circuit conductor 2 is adjusted so that the gold content in the connection material 4 after connection is 90% by mass, the melting point of the connection material 4 after connection is about 400 ° C. In order to give higher heat resistance, an alloy having a melting point of 780 ° C., Ag 72% by mass—Cu 28% by mass, and a melting point of 650 ° C., Ag 55% by mass—Cu 22% by mass—Zn 17% by mass—Sn 5% by mass. Use it.

  As the bonding material 5, glass or resin can be used. Examples of the glass include low-melting glass such as PbO glass, PbO—SiO glass, BiO—SiO glass, PO—SiO glass, and BO—SiO glass. Examples of the resin include an epoxy resin, a polyimide resin, a polyamideimide resin, and a polyetherimide resin. In any case, in order to make the thermal expansion coefficient close to that of the substrate 1 or the frame body 6, for example, it may contain a filler such as inorganic powder such as silica. When the bonding material 5 is a low melting point glass, for example, a glass component containing 56 to 66% by mass of lead oxide, 4 to 14% by mass of boron oxide, 1 to 6% by mass of silicon oxide, and 1 to 11% by mass of zinc oxide. A glass paste obtained by adding and mixing a suitable organic solvent and solvent to a powder obtained by adding 4 to 15% by mass of a zirconium oxide silica-based compound powder as a filler is printed on the lower surface of the frame 6 by a printing method such as a screen printing method. A glass layer is deposited on the frame 6 by printing and coating the film on a predetermined thickness and firing at a temperature of about 430 ° C. The frame body 6 is placed on the base 1 in which the lead terminal 3 is connected to the circuit conductor 2 in advance with the glass layer facing down, and is heated to about 470 ° C. by a heating device such as a tunnel type atmospheric furnace or oven. Thus, the bonding material 5 is remelted so that the periphery of each lead terminal 3 sandwiched between the upper surface of the substrate 1 and the outer peripheral edge of the frame body 6 is covered with the bonding material 5 and cooled to solidify the glass layer. The body 6 and the lead terminal 3 are firmly joined to the base 1 to produce an image sensor housing package. When the bonding material 5 is a resin, for example, tetrahydromethyl phthalic anhydride is added as a curing agent to the main agent composed of a liquid epoxy resin of bisphenol A type by external addition, and silica powder is used as a filler. The epoxy resin paste obtained by adding 30 to 80% by mass by external addition and adding and mixing a colorant such as carbon black and an organic solvent such as 2-methoxyethanol is added to the frame 6 by a printing method such as a screen printing method. The bottom surface is printed and applied to a predetermined thickness, and the solvent is dried at a temperature of about 60 ° C. to 80 ° C. to adhere the resin layer to the frame 6. The frame body 6 is placed on the base 1 in which the lead terminal 3 is connected to the circuit conductor 2 in advance with the bonding material 5 down, and heated by a tunnel-type atmosphere furnace or a heating device such as an oven to obtain a peak temperature. By holding at about 150 ° C. for 1 hour, the resin layer is melted and the periphery of each lead terminal 3 sandwiched between the upper surface of the substrate 1 and the outer peripheral edge of the frame body 6 is covered with resin, and then cured. 6 and the lead terminal 3 are firmly bonded to the base 1 to form an image sensor housing package.

As described above, the linear thermal expansion coefficient of the bonding material 5 is preferably larger than the linear thermal expansion coefficient of the lead terminal 3. As such a combination, for example, the lead terminal 3 is made of an Fe-29% Ni-17% Co alloy (linear thermal expansion coefficient: 6 × 10 ⁻⁶ / ° C. (30 ° C. to 500 ° C.)), and the bonding material 5 For example, a powder of zirconium oxide silica compound as a filler is added to a glass component containing 56 to 66% by mass of lead oxide, 4 to 14% by mass of boron oxide, 1 to 6% by mass of silicon oxide, and 1 to 11% by mass of zinc oxide. 4-15 mass% added low melting point glass (linear thermal expansion coefficient: 7 × 10 ⁻⁶ / ° C.) or lead terminal 3 made of copper (linear thermal expansion coefficient: 16.8 × 10 ⁻⁶ / ° C.) In addition, the bonding material 5 was added to the epoxy resin with 20% by mass of tetrahydromethylphthalic anhydride as a curing agent added to the epoxy resin, and β-eucryptite (LiAlSiO ₄ , linear thermal expansion coefficient: −8 × as a filler) 10 ^-6 / ° C.) an epoxy resin By adding outside 250 wt% for some cases, such as where the linear expansion coefficient of about 18 × 10 ^{-6 /} ℃. If the difference between the linear thermal expansion coefficients is too large, particularly when the bonding material 5 is made of glass, the bonding material 5 may crack. Therefore, the linear thermal expansion coefficient of the lead terminal 3 and the linear heat of the bonding material 5 The difference from the expansion coefficient is more preferably about 1 to 3 × 10 ⁻⁶ / ° C.

  The frame 6 is made of ceramics such as an aluminum oxide sintered body (alumina ceramics), a mullite sintered body, a steatite sintered body, an aluminum nitride sintered body, and the like. It can be produced by a method similar to that described above. It is preferable to use the same material for the frame body 6 and the base body 1 because the thermal expansion coefficients are the same, so that the thermal stress generated between them is not applied to the sealing material 5 or the lead terminal 3 therebetween.

  When the surface of the frame body 6 is also flattened by lapping or the like to have a flatness of 20 μm or less, the frame body 6 is inclined with respect to the base body 1 and the translucent lid 8 is inclined with respect to the frame body 6. The translucent lid 8 is preferably bonded without being inclined with respect to the image sensor 9 as a result. In particular, for example, when a dielectric multilayer film is formed on the translucent lid 8 to function as an IR cut filter, an IR cut filter having a desired function can be obtained due to no inclination.

The insulating layer 11 has substantially the same thermal expansion coefficient as that of the lead terminal 3. The thermal expansion coefficient substantially the same as the thermal expansion coefficient of the lead terminal 3 is a thermal expansion coefficient in the range of about ± 1 × 10 ⁻⁶ / ° C. of the lead terminal 3. If the lead terminal 3 is made of an Fe-29% Ni-17% Co alloy (linear thermal expansion coefficient: 6 × 10 ⁻⁶ / ° C. (30 ° C. to 500 ° C.)), for example, the insulating layer 11 is oxidized. 4-15 masses of zirconium oxide silica-based compound powder as filler in a glass component containing 56-66 mass% lead, 4-14 mass% boron oxide, 1-6 mass% silicon oxide and 1-11 mass% zinc oxide % Added low-melting glass (linear thermal expansion coefficient: 7 × 10 ⁻⁶ / ° C.) may be used. Alternatively, when the lead terminal 3 is made of copper (coefficient of linear thermal expansion: 16.8 × 10 ⁻⁶ / ° C.), for example, tetrahydromethylphthalic anhydride as a curing agent may be added to the epoxy resin as an external additive to the epoxy resin. The addition of β-eucryptite (LiAlSiO ₄ , linear thermal expansion coefficient: −8 × 10 ⁻⁶ / ° C.) as a filler to the epoxy resin was added 270% by mass (linear expansion coefficient: about 16.8). × 10 ⁻⁶ / ° C.) may be used. In this case, the bonding material 5 is preferably made of a resin. Or, for example, a glass component comprising 74% by mass of silicon oxide, 14% by mass of lithium oxide, 4% by mass of aluminum oxide, 2% by mass of phosphorus pentoxide, 2% by mass of potassium oxide, 2% by mass of zinc oxide, and 2% by mass of sodium oxide. Glass ceramics (linear thermal expansion coefficient: about 17 × 10 ⁻⁶ / ° C.) composed of 50% by mass and cristobalite 50% by mass may be used. In this case, the bonding material 5 may be made of a resin or glass having a melting point lower than that of the insulating layer 11.

  The insulating layer 11 may be insulative, such as inorganic materials such as glass and ceramics, organic materials such as epoxy resins, or mixtures thereof. Since it is insulative, even if the insulating layer 11 is formed over the adjacent circuit conductors 2 and 2 as in the example shown in FIG. 6B, a short circuit occurs between the adjacent circuit conductors 2 and 2. There is no.

  The insulating layer 11 has the same width and thickness as the lead terminal 3 and is formed from the inner end portion of the lead terminal 3 to the inner end portion of the bonding material 5 as in the example shown in FIG. As in the example shown in FIGS. 8B to 8F, when the lead terminal 3 has convex portions or concave portions on the upper and lower surfaces and side surfaces thereof, the thickness and width of the portion without the convex portions or concave portions may be used. In the case where the lead terminal 3 is formed with a portion 3a having a different bottom thickness and having a high bottom surface as in the example shown in FIG. 5, the lead terminal 3 has the same thickness as the inner end portion of the lead terminal 3. do it. If it does in this way, only the outer side of the frame 6 will differ in the thermal expansion of the member located between the frame 6 and the base | substrate 1. FIG. Even if the outer side of the frame body 6 is distorted due to thermal expansion, the translucent lid 8 is positioned inside the frame body 6, and therefore, the adhesive reliability of the translucent lid 8 and the optical properties on the translucent lid 8. The influence on the filter is small.

  In order to form the insulating layer 11, for example, if the insulating layer 11 is made of the resin as described above, it may be formed by applying and curing a resin paste in a predetermined shape at a predetermined position. In the case of glass, a glass paste may be applied in the same manner and melted and solidified. In the case of the glass ceramic as described above, a sintered body having a predetermined size may be prepared, placed at a predetermined position, and fixed by the bonding material 5. A metallized layer may be formed on the surface, and when the lead terminal 3 is connected to the circuit conductor, the same connecting material 4 may be used for connection.

  The image pickup apparatus of the present invention includes the image pickup device storage package of the present invention as described above, and the image pickup device 9 mounted on the mounting portion 1a of the image pickup device storage package and electrically connected to the plurality of lead terminals 3. And a translucent lid 8 bonded to the upper surface of the frame 6 with an adhesive 7. As a result, an imaging device with high electrical connection reliability and airtight reliability is obtained.

  The image sensor 9 is a CCD, a CMOS, or the like. For example, the imaging element 9 is bonded and fixed to the mounting portion 1a on the upper surface of the base 1 with a conductive adhesive made of an epoxy resin containing silver powder, and the electrode of the imaging element 9 and the circuit conductor 2 are bonded with gold or the like. The wire 10 is connected to be electrically connected to the image sensor storage package. Then, the translucent lid 8 is hermetically bonded with the adhesive 7 so as to close the hole of the frame body 6, thereby forming an imaging device.

  The translucent lid 8 can be a translucent plate made of glass or quartz.

  A filter may be formed on the translucent lid 8. This is preferable because the thickness of the imaging device can be reduced as compared with the case where a separately created filter is disposed on the translucent lid 8. As a filter, there is a low-pass filter that overlaps two or three crystal plates having different crystal orientation angles and prevents a moire phenomenon that occurs in an image captured by the image sensor 9 using the birefringence characteristics of the crystal plate. When a crystal plate is used as the translucent lid 8, the translucent lid 8 can be used as one crystal plate of the low-pass filter. Further, in order to match the image pickup device 9 whose sensitivity from the red to the infrared region is higher than that of human vision with the color sensitivity of the human eye, light of wavelengths from the red to the infrared region is cut. There is also an IR cut filter for this purpose. The IR cut filter can be manufactured by alternately forming several tens of dielectric multilayer films on the surface of the translucent lid 8. The dielectric multilayer film is generally formed by a high refractive index dielectric layer made of a dielectric material having a refractive index of 1.7 or more and a low refractive index dielectric layer made of a dielectric material having a refractive index of 1.6 or less by an evaporation method or the like. It is formed by alternately stacking several tens of layers using a sputtering method or the like. Examples of the dielectric material having a refractive index of 1.7 or more include tantalum pentoxide, titanium oxide, niobium pentoxide, lanthanum oxide, and zirconium oxide. Examples of the dielectric material having a refractive index of 1.6 or less include silicon oxide and Aluminum oxide, lanthanum fluoride, magnesium fluoride, etc. are used.

  The adhesive 7 may be made of an epoxy resin such as a thermosetting type or an ultraviolet curable type. For example, an ultraviolet curable epoxy resin is applied to the upper surface of the frame body 6 over the entire periphery of the frame body 6 by using a dispensing method, and a translucent lid 8 is placed thereon to irradiate ultraviolet rays. The agent 7 is cured and sealed.

DESCRIPTION OF SYMBOLS 1: Base | substrate 1a: Mounting part 2: Circuit conductor 3: Lead terminal 3a: The part where the lower surface is high 4: Connection material 5: Joining material 6: Frame body 7: Adhesive 8: Translucent lid 9: Image sensor
10: Bonding wire
11: Insulation layer

Claims (6)

A base having an image sensor mounting portion at the center of the upper surface; a plurality of circuit conductors arranged from the mounting portion to the outer peripheral portion of the upper surface of the base; and a plurality of circuit conductors connected to the plurality of circuit conductors, respectively. A plurality of lead terminals extending to the frame, a frame that surrounds the mounting portion and faces the base from the connection portion between the circuit conductor and the lead terminal, and a space between the frame and the base In the image pickup device storage package, the lead terminal has a portion with a lower surface extending from the outside of the connection portion to the outer periphery of the base body. . 2. The image sensor housing package according to claim 1, wherein the thermal expansion coefficient of the bonding material is larger than the thermal expansion coefficient of the lead terminal. 3. The image sensor housing package according to claim 1, wherein the lead terminal has a quadrangular shape in which a cross section perpendicular to the length direction has rounded corners. 4. The lead terminal has at least one of a convex portion and a concave portion on at least one of upper and lower surfaces and side surfaces from a connection portion between the circuit conductor and the lead terminal to an outer periphery of the base. The image sensor housing package according to any one of claims 1 to 3. From the inner end of the lead terminal to the inner end of the bonding material, it has an insulating layer having the same width and thickness as the lead terminal and substantially the same thermal expansion coefficient as the lead terminal. The image sensor housing package according to any one of claims 1 to 3, wherein An image pickup device storage package according to any one of claims 1 to 5, an image pickup device mounted on the mounting portion of the image pickup device storage package and electrically connected to the plurality of lead terminals. An imaging apparatus comprising: a light-transmitting lid bonded to the upper surface of the frame with an adhesive.

Images