JP2006156528A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device that is improved in the reliability of hermetically sealing by improving the parallelism of a lid to an insulating substrate and, at the same time, can prevent deposition of contamination to the utmost in a process, even when, for example, an optical semiconductor element is housed and can accurately receive light by preventing the occurrence of flaws and chips in a translucent lid when the lid is the translucent lid. <P>SOLUTION: The semiconductor device 9 is provided with the insulating substrate 1 having a recess 1a for housing a semiconductor element 3 on its top surface and, at the same time, first and second steps 1b and 1c sequentially formed from the inside of the recess 1a to the outside so that the heights of the steps 1b and 1c may become higher sequentially, wiring conductors 2 formed from the internal surface of the recess 1a to at least either the side face or bottom surface of the insulating substrate 1, and the semiconductor element 3 placed on the bottom face of the recess 1a and having electrodes 4 electrically connected to the wiring conductors 2. The semiconductor device 9 is also provided with the lid 5 arranged on the first step 1b. The insulating substrate 1 and lid 5 are bonded to each other with a bonding material 7 packed between the second step 1c and the side face of the lid 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device in which a semiconductor element is accommodated in a semiconductor element accommodation package and hermetically sealed with a lid.

  Semiconductor integrated circuit elements used in CPUs (Central Processing Units), memories, etc., optical semiconductor elements that are light receiving elements such as photodiodes (PD), line sensors, image sensors, or optical semiconductor elements having these light receiving portions A package for housing a semiconductor element for housing a semiconductor element in an airtight manner includes an insulating base having a recess formed on the top surface for storing the semiconductor element, and a wiring conductor led out from the inside of the recess of the insulating base. It has a built-in structure.

  The semiconductor element is mounted and bonded to the bottom surface of the recess of the insulating base, and an electrode is provided on the outer periphery of the upper surface of the semiconductor element. The electrode of the semiconductor element and the portion of the wiring conductor exposed at the inner surface of the recess are electrically connected by a bonding wire made of Au, Al or the like.

  In addition, a lid made of ceramic, metal (Fe—Ni—Co alloy, copper alloy, etc.), glass, organic resin or the like is bonded and fixed to the upper surface of the insulating substrate via a bonding material made of resin such as epoxy resin, and the concave portion. As a result, the semiconductor element is hermetically sealed inside the container formed by the insulating base and the lid.

  As described above, the conventional semiconductor device prevents foreign matters such as dust from entering the internal space of the semiconductor device by the lid, and makes the internal space of the semiconductor device a sealed space, so that moisture in the external atmosphere can be prevented. Intrusion into the semiconductor device is prevented and the durability of the semiconductor element is improved.

  Note that a portion of the wiring conductor led out to the outside of the recess functions as a conductor for external connection.

  For example, when an optical semiconductor element is used as the semiconductor element, the lid is formed of a translucent material, and external light is received by the light receiving surface of the optical semiconductor element via the translucent lid. It is converted into an electrical signal by an optical semiconductor element. This electric signal is sent to various devices and elements arranged outside the semiconductor device via a wiring conductor and an external electric circuit electrically connected to the wiring conductor.

In order to attach the lid to the insulating substrate, for example, when a thermosetting resin is used as the bonding material, after the semiconductor element is accommodated in the recess of the insulating substrate, the outer peripheral portion of the upper surface of the insulating substrate An uncured resin is applied to the substrate, and the lower surface of the lid body and the upper surface of the insulating base are positioned and set with the resin interposed therebetween to effect the resin.
JP 2004-71938 A

  However, in such a conventional semiconductor device, since the bonding material is interposed between the lid and the insulating base and it is difficult to maintain the height of the bonding material constant, the following problems occur. There was a problem. That is, the bonding strength of the lid body to the insulating base varies due to the lid body being tilted and attached to the insulating base body, or the thickness of the bonding material partially varying, so that the lid body is insulated. The reliability of bonding to the substrate is lowered, and the reliability of hermetic sealing is deteriorated.

  For example, when the semiconductor element is an optical semiconductor element, the distance between the light receiving surface of the optical semiconductor element and the translucent cover varies as a result of the tilting of the lid, and external light incident on the light receiving surface is reflected. Distortion occurs and it becomes impossible to receive light accurately.

  In addition, foreign materials (dust, mist, etc.) in the external environment may enter the recesses after the semiconductor element is accommodated in the recesses of the insulating base and before the lid is joined to the insulating base and the recesses are closed. In the case where the foreign matter is a conductive foreign matter, there is a problem in that it adheres to the electrode of the semiconductor element, the wiring conductor, the bonding wire connecting the semiconductor element and the wiring conductor, etc., and causes a problem such as an electrical short circuit. . In addition, when the semiconductor element is an optical semiconductor element, foreign matter adheres to the light receiving portion of the optical semiconductor element, so that the light receiving characteristics of the optical semiconductor element deteriorate.

  In addition, the entry of the foreign matter into the concave portion is, in the manufacturing process of the semiconductor device, prior to sealing with the lid, during the appearance inspection process, and handling up to the sealing process (retention, transport, positioning work, etc.) This is caused by the opening of the recess.

  Therefore, the present invention has been completed in view of the above problems, and its purpose is that the parallelism of the lid body with respect to the insulating base is good, the reliability of hermetic sealing, and for example, the semiconductor element is an optical semiconductor element. Another object of the present invention is to provide a semiconductor device that is excellent in light receiving characteristics and the like and in which foreign substances are effectively prevented from entering the recesses.

  In the semiconductor device of the present invention, the first stepped portion and the second stepped portion are formed so as to form a concave portion in which the semiconductor element is accommodated on the upper surface and gradually increase in height from the inner side to the outer side of the concave portion. An insulating base on which the step portions are sequentially formed, a wiring conductor formed from the inner surface of the concave portion to at least one of the side surface and the lower surface of the insulating base, and a bottom surface of the concave portion. A semiconductor device comprising a semiconductor element having an electrode to be connected electrically, and a lid disposed on the first step portion, wherein the insulating base and the lid are connected to the second step. It joins via the joining material with which it fills between a part and the side surface of the said cover body.

  In the semiconductor device of the present invention, the bonding material is formed in a convex shape so that the upper end of the bonding material is positioned above the upper surface of the insulating base and the upper surface of the lid.

  Furthermore, the semiconductor device of the present invention is characterized in that the bonding material is formed by curing an ultraviolet curable resin.

  Furthermore, the semiconductor device of the present invention is characterized in that the bonding material is disposed only outside the first step portion.

  In the semiconductor device of the present invention, the first stepped portion and the second stepped portion are formed so that a recess for accommodating the semiconductor element is formed on the upper surface, and the height gradually increases from the inside of the recess toward the outside around the recess. An insulating base in which stepped portions are sequentially formed, a wiring conductor formed from the inner surface of the recess to at least one of the side surface and the lower surface of the insulating base, and placed on the bottom surface of the concave and electrically connected to the wiring conductor A semiconductor device comprising a semiconductor element having an electrode and a lid disposed on a first step portion, wherein the insulating base and the lid are disposed between the second step portion and a side surface of the lid. Since the bonding material is filled via the bonding material, the bonding material does not intervene between the upper surface of the insulating base (the upper surface of the first stepped portion) and the lower surface of the lid. Effectively prevent the tilting of the lid due to variations in thickness Therefore, it is possible to obtain a semiconductor device in which the parallelism of the lid to the insulating substrate is good. For example, when the semiconductor element is an optical semiconductor element, the parallelism between the lid and the light receiving surface of the optical semiconductor element is excellent, and the incident light from the outside can be accurately received by the light receiving portion of the optical semiconductor element. In addition, an optical semiconductor device having excellent light receiving characteristics can be obtained.

  In addition, since the insulating base and the lid can be firmly bonded via a bonding material filled between the second stepped portion and the side of the lid, the reliability of hermetic sealing is ensured well. can do.

  Further, in the step of bonding the lid body to the insulating base with the bonding material, the lid body is temporarily placed on the upper surface of the first step portion to block the concave portion without applying the bonding material to the lower surface of the lid body in advance. In the semiconductor device manufacturing process, foreign matter enters the recesses before sealing with the lid, during the appearance inspection process, and during the handling up to the sealing process (retention, transport, positioning work, etc.). Can be prevented. For this reason, foreign matter adheres to the semiconductor element, etc., causing an electrical short circuit between the electrodes of the semiconductor element or the like, for example, when the semiconductor element is an optical semiconductor element, it adheres to the light receiving surface and degrades the light receiving characteristics. Is also effectively prevented.

  Furthermore, even when the lid is made of glass, the edge portion where the glass fragments are easily peeled is covered with the bonding material filled in the second step portion and the side surface of the lid, so that the edge portion Thus, it is possible to effectively prevent the glass fragments from peeling off.

  Further, according to the semiconductor device of the present invention, the upper end of the bonding material is formed in a convex shape so as to be positioned above the upper surface of the insulating base and the upper surface of the lid, so that the lid is made of translucent glass. Even if it is formed by, etc., the outer peripheral part of the lid that is easy to come into contact with external devices etc. will be protected with a bonding material, and the lid will be accidentally scratched when handling the optical semiconductor device Can be effectively prevented.

  In this case, since the upper end portion of the bonding material covering the outer peripheral portion of the upper surface of the lid body is located higher than the upper surface of the lid body, when the optical semiconductor device comes into contact with an external device, jig, etc., first the lid The upper end portion of the bonding material covering the outer peripheral portion of the upper surface of the body is brought into contact with the upper surface of the body, and this can effectively prevent the upper surface of the lid from being scratched.

  Furthermore, according to the semiconductor device of the present invention, since the ultraviolet curable resin is cured to form a bonding material, the semiconductor element and the insulating base are not added with an excessive heat history, and the reliability of the semiconductor element is reduced. It is possible to effectively prevent the adhesion of the semiconductor element and the insulating base and the deterioration of the connection reliability.

  Furthermore, according to the semiconductor device of the present invention, by disposing the bonding material only outside the first step portion, it is possible to eliminate the bonding material from spreading to the center of the lid. Therefore, when an optical semiconductor element is used as the semiconductor element and the lid is formed of a light-transmitting material, the bonding material hardly interferes with the reception of external light, and the light receiving characteristics can be further improved. it can.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of an embodiment of a semiconductor device of the present invention. In FIG. 1, 1 is an insulating substrate, 2 is a wiring conductor, 3 is a semiconductor element, 5 is a lid, and 7 is a bonding material. is there. A semiconductor device 9 is mainly composed of the insulating base 1, the wiring conductor 2, the semiconductor element 3, the lid 5 and the bonding material 7.

  The semiconductor element 3 is accommodated in the recess 1 a formed on the upper surface of the insulating substrate 1, and is bonded to the bottom surface of the recess 1 a by the adhesive 6.

  The semiconductor element 3 includes a semiconductor integrated circuit element used in a CPU (central processing unit), a memory, and the like, an optical semiconductor element that is a light receiving element such as a photodiode (PD), a line sensor, and an image sensor, or a light receiving portion thereof. An optical semiconductor element or the like.

  For example, in the case of an optical semiconductor element, the semiconductor element 3 is provided with a light receiving portion at the center of the upper surface and an electrode for signal input / output at the outer peripheral portion of the upper surface.

  The insulating substrate 1 is made of ceramics such as alumina ceramics, aluminum nitride ceramics, silicon carbide ceramics, silicon nitride ceramics, glass ceramics, and the like, and a separate frame-shaped side wall portion on the outer peripheral portion of the upper surface of the flat plate-like bottom plate portion. May be provided, or the bottom plate portion and the side wall portion of the insulating substrate 1 may be integrally formed. The bottom plate portion and the side wall portion form a recess 1 a for housing the semiconductor element 3 on the upper surface of the insulating base 1.

  A wiring conductor 2 is formed from the inside of the recess 1a of the insulating base 1 to at least one of the side surface and the lower surface of the insulating base 1.

  The portion of the wiring conductor 2 exposed on the inner surface of the recess 1 a is connected to the electrode of the semiconductor element 3 via the bonding wire 8, so that the semiconductor element 3 accommodated in the recess 1 a is connected to the electrode 4 and the bonding wire 8. And, it is led out to the outside of the recess 1 a through the wiring conductor 2. By connecting the lead-out portion of the wiring conductor 2 to an external electric circuit, the semiconductor element 3 is electrically connected to the external electric circuit.

  The wiring conductor 2 is exposed on the inner surface of the recess 1a on the top surface of the stepped portion formed between the inner surface and the bottom surface of the recess 1a in FIG. 1, but is exposed on the bottom surface of the recess 1a. May be.

  The wiring conductor 2 described above is formed of a metallized conductor such as tungsten, molybdenum, copper, or silver. The wiring conductor 2 is formed with a predetermined through hole in advance in a ceramic green sheet (hereinafter also referred to as a green sheet) to be the insulating base 1, for example, and a metal paste such as tungsten, molybdenum, copper, or silver is used for the green sheet. It is formed by printing or filling the surface or the inner surface of the through hole.

  Then, the recess 1 a in which the semiconductor element 3 is accommodated is closed by the lid 5, and the semiconductor element is hermetically accommodated in a container made up of the insulating base 1 and the lid 5 to constitute the semiconductor device 9. .

  The lid 5 is made of glass such as optical glass, soda lime glass, lead glass, borosilicate glass, resin materials such as acrylic resin, epoxy resin, polyimide resin, aluminum oxide sintered body, and glass ceramic sintered body. Or a metal material such as an iron-nickel-cobalt alloy or iron-nickel alloy.

  The lid 5 is formed of a light-transmitting material such as glass or resin if the semiconductor element 3 is an optical semiconductor element, for example.

  Furthermore, the first step portion 1b and the second step portion 1c are sequentially formed around the recess 1a of the insulating base 1 so that the height gradually increases from the inside to the outside of the recess 1a. Has been.

  The first step portion 1b has a function of supporting the lid body 5 with the lid body 5 disposed on the upper surface thereof.

  In addition, the second step portion 1c has a function of filling the bonding material 7 between the side surface of the lid body 5 disposed on the first step portion 1c, and the bonding material 7 The insulating substrate 1 is joined.

  The lid 5 is mounted and positioned on the first step portion 1b described above, and then the bonding material 7 is filled in the space surrounded by the side surface of the outer peripheral portion of the lid 5 and the second step portion 1c of the insulating base 1. Then, by applying a predetermined treatment such as curing, the side surface of the lid body 5 and the insulating base 1 (second stepped portion 1c) are bonded via the bonding material 7, and the recess in which the semiconductor element 3 is mounted and accommodated 1a is hermetically sealed.

  As the bonding material 7, a resin material such as an acrylic resin, an epoxy resin, a silicone resin, or a polyetheramide resin, a solder material such as AuSn or PbSn, a low melting point glass material, or the like is used.

  When the semiconductor element 3 is an optical semiconductor element, the bonding material 7 is mixed with dark pigments or dyes such as black, brown, dark green, and dark blue in order to block unnecessary external light. Also good.

  The bonding material 7 can be filled by, for example, applying and filling the uncured resin material by a dispensing method, a screen printing method, or the like.

  In this case, the 2nd recessed part 1 does not need to make an inner surface a perpendicular | vertical surface, and is good also as a surface inclined inside or outside. For example, when the inner side surface of the second stepped portion 1c is gradually inclined inward from the upper end to the lower end, the bonding material 7 can be filled more easily.

  Further, when the inner side surface of the second step portion 1c is gradually inclined outward from the upper end to the lower end, a larger volume can be secured for the bonding material 7 and the bonding material enters the inclined inner side. Thus, the anchor effect can be obtained, and the joining of the lid 5 can be made stronger. The direction of inclination is the properties of the bonding material 7 and the lid 5 to be used (easiness of wetting of the bonding material 7 with respect to the lid 5, bonding strength, etc.), the size and shape of the lid 5 and the second stepped portion 1 c, What is necessary is just to determine suitably according to the characteristic etc. which are requested | required of a semiconductor device (The level of the reliability of airtight sealing, the request | requirement for workability of airtight sealing, etc.).

  According to the semiconductor device 9 of this embodiment as described above, as described above, the lid body 5 is disposed on the first step portion 1b, and the insulating base 1 and the lid body 5 are connected to the second step portion 1c. Since bonding is performed via the bonding material 7 filled between the side surfaces of the lid body 5, the gap between the upper surface of the insulating base 1 (the upper surface of the first step portion 1 b) and the lower surface of the lid body 5. In this case, the bonding material 7 is not interposed, and the inclination of the lid 5 due to the variation in the thickness of the bonding material 7 can be effectively prevented, and the parallelism of the lid 5 with respect to the insulating substrate 1 is good. The semiconductor device 9 can be obtained. For example, when the semiconductor element 3 is an optical semiconductor element, the parallelism between the lid 5 and the light receiving surface of the optical semiconductor element is excellent, and incident light from outside can be accurately received by the light receiving portion of the optical semiconductor element. An optical semiconductor device having excellent light receiving characteristics can be obtained.

  In addition, since the insulating substrate 1 and the lid 5 can be firmly bonded via the bonding material 7 filled between the second stepped portion 1c and the side surface of the lid 5, the reliability of hermetic sealing is achieved. Good properties can be secured.

  Further, in this case, in the step of bonding the lid 5 to the insulating base 1 with the bonding material 7, the lid 5 is temporarily applied to the upper surface of the first step portion 1 b without applying the bonding material to the lower surface of the lid 5 in advance. Since the recess 1a can be placed and closed, in the manufacturing process of the semiconductor device 9, before the sealing by the lid 5, the appearance inspection process, and the handling up to the sealing process (retention, transport, positioning work, etc.) In this case, foreign matter can be prevented from entering the recess 1a. For this reason, foreign matters adhere to the semiconductor element 3 or the like, and an electrical short circuit between the electrodes of the semiconductor element 3 or the like, for example, when the semiconductor element 3 is an optical semiconductor element, adhere to the light receiving surface and deteriorate light receiving characteristics. Etc. can be prevented.

  The semiconductor device 9 of the present invention is preferably formed in a convex shape so that the upper end of the bonding material 7 is positioned above the upper surface of the insulating base 1 and the upper surface of the lid 5. In this case, even if an optical semiconductor element is used as the semiconductor element 3 and the lid 5 is formed of a light-transmitting material such as glass, the outer peripheral portion of the lid that is easily in contact with an external device or the like is the bonding material 7. Thus, it is possible to effectively prevent the transparent cover from being accidentally damaged when the semiconductor device 9 (optical semiconductor device) is handled.

  Further, since the upper end portion of the bonding material 7 covering the outer peripheral portion of the upper surface of the lid body is at a position higher than the upper surface of the translucent lid body, when the optical semiconductor device comes into contact with an external device, jig, or the like First, it comes into contact with the upper end portion of the bonding material 7 covering the outer peripheral portion of the upper surface of the lid, and this can also effectively prevent the upper surface of the lid made of glass or the like from being scratched. .

  In the semiconductor device 9 described above, it is preferable to form the bonding material 7 by curing an ultraviolet curable resin. In this case, an excessive heat history is not added to the semiconductor element 3 and the insulating base 1, and a decrease in the reliability of the semiconductor element 3 can be effectively prevented. A decrease in connection reliability is also effectively prevented.

  In the above-described semiconductor device, it is preferable that the bonding material is disposed only outside the first step portion. In this case, since it is possible to eliminate the spread of the bonding material 7 to the center portion of the lid body 5, an optical semiconductor element is used as the semiconductor element 3 and the lid body 5 is formed of a translucent material. However, the bonding material 7 is less likely to inhibit the reception of external light, and the light receiving characteristics can be further improved.

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

It is sectional drawing which shows an example of embodiment of the semiconductor device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 1a .... Recessed part 1b .... 1st level | step difference part 1c .... 2nd level | step difference part 2 ... Wiring conductor 3 ... Semiconductor element 4 ... Electrode 5 ... Cover body 6 ... Adhesive 7 ... Joint material 8 ... Bonding wire 9 ... Semiconductor device

Claims (4)

A recess for accommodating a semiconductor element is formed on the upper surface, and a first step portion and a second step portion are sequentially formed around the recess so that the height gradually increases from the inside to the outside of the recess. An insulating substrate,
A wiring conductor formed from the inner surface of the recess to at least one of the side surface and the lower surface of the insulating base;
A semiconductor element mounted on the bottom surface of the recess and having an electrode electrically connected to the wiring conductor;
A semiconductor device comprising a lid disposed on the first step portion,
A semiconductor device characterized in that the insulating base and the lid are bonded via a bonding material filled between the second stepped portion and a side surface of the lid. 2. The semiconductor device according to claim 1, wherein an upper end of the bonding material is formed in a convex shape so as to be positioned above the upper surface of the insulating base and the upper surface of the lid. The semiconductor device according to claim 1, wherein the bonding material is formed by curing an ultraviolet curable resin. The semiconductor device according to claim 1, wherein the bonding material is disposed only outside the first step portion.

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