JP2010040920A - Optical semiconductor device and method of manufacturing same - Google Patents

Abstract

An object of the present invention is to provide an optical semiconductor device that can be accurately coated with a sealing resin while avoiding a light receiving region of a semiconductor light receiving element, and a method for manufacturing the same.
An optical semiconductor device of the present invention includes a semiconductor light receiving element having a light receiving region, an electrode body on the mounting substrate, and a connection for electrically connecting the semiconductor light receiving element and the electrode body, which are disposed on the mounting substrate. An optical semiconductor device provided with a body is assumed. In the optical semiconductor device of the present invention, the insulating wall is formed around the light receiving region of the semiconductor light receiving element. The sealing resin is in contact with the outer peripheral surface of the insulating wall and covers the semiconductor light receiving element and the mounting substrate within a range extending over the outer edge of the mounting substrate.
[Selection] Figure 1

Description

  The present invention relates to an optical semiconductor device used for an optical pickup or the like and a manufacturing method thereof, and more particularly to a resin-sealed optical semiconductor device.

  Conventionally, an optical semiconductor device used for an optical pickup has been packaged by a structure in which a semiconductor light receiving element is disposed on a mounting substrate on which electrodes are formed, and the entire surface of the semiconductor light receiving element is covered with a transparent protective layer of a sealing resin. It was. This transparent protective layer prevents the portions such as bonding pads, bonding wires, and light receiving areas formed on the semiconductor light receiving element from being corroded by moisture contained in the outside air, and protects the light receiving device from characteristic deterioration caused by dust. It has a function.

  The optical semiconductor light receiving element is used, for example, as an optical pickup of an optical disk apparatus represented by a CD-R (Compact Disk-Recordable) drive and a DVD (Digital Versatile Disk) drive. Further, the configuration is generated by a photodiode that is a light receiving region for receiving laser light reflected by an optical disk such as a DVD loaded in the DVD drive or the like, and a photodiode based on the received laser light. It consists of a signal processing circuit area for processing electrical signals.

  On the other hand, the semiconductor laser as the light source has been demanded to increase the operation speed of the optical disk device and to increase the storage capacity. In recent years, the energy density has increased and the wavelength has been shortened. For this reason, a red semiconductor laser that emits light with a wavelength of 650 nm has been used in the past, but now it is changing to a system that uses a blue semiconductor laser that emits a wavelength of 405 nm, which is a shorter wavelength.

  Since the short wavelength laser with high energy density changes the color of the resin, when the photodiode, which is the light receiving region of the light receiving element, is covered with a transparent protective layer made of resin, the color of the transparent protective layer is also changed. For this reason, the light transmittance of the light receiving region is lowered, the amount of laser light that can reach the light receiving element is reduced, and the device characteristics fluctuate.

As a method for solving such a problem, a technique in which a light receiving region is not covered with a sealing resin is known. In the optical semiconductor device disclosed in Patent Document 1, a bare chip of a semiconductor light receiving element is mounted on a mounting substrate, and a bonding pad on the bare chip and a lead electrode of the mounting substrate are connected by wire bonding, The bonding wire is molded with resin. In this technique, as shown in FIG. 6, the polyimide thin film 100 is formed by photolithography so as to surround the periphery of the light receiving region, and then, for example, a silicon-based sealing resin 124 is applied on the semiconductor light receiving element other than the light receiving region and on the mounting substrate. Pour over the outer edge of the Since the surface tension of the silicon-based resin is larger than the surface tension of the polyimide, the silicon-based sealing resin 124 stays on the polyimide thin film 100 and seals the semiconductor light receiving element with the opening formed on the light receiving surface. Thereby, a bare chip in which an opening is formed in the light receiving region 112 can be formed. Furthermore, the technique disclosed in Patent Document 2 fills the mold with sealing resin in a state where the columnar protrusions formed on the mold are in contact with the light receiving region. This prevents the light receiving region from being resin-sealed.
JP 2007-189182 A US Patent Application Publication No. 2006/0196412

  However, in the technique described in Patent Document 1, since the opening is formed on the light receiving region 112 by utilizing the surface tension due to the material property difference between the sealing resin 124 and the polyimide, the light receiving region 112 is complicated and has a fine pattern. When it becomes, it becomes difficult to form a uniform opening region. For example, when a plurality of light receiving surfaces are provided in one light receiving element, the sealing resin 124 is difficult to flow uniformly on the polyimide thin film of the light receiving element, so that the entire sealing area outside the light receiving area 112 is uniformly sealed. It becomes difficult to coat with the resin. Therefore, it is impossible to cope with the complexity of the light receiving region due to the miniaturization of the multilayer disk or the optical semiconductor device. Furthermore, in the technique described in Patent Document 2, since the impact from the columnar protrusion is directly applied to the light receiving element, cracks are likely to occur in the light receiving element.

  SUMMARY OF THE INVENTION The present invention solves such problems, and an object of the present invention is to provide an optical semiconductor device that can be accurately coated with a sealing resin while avoiding a light receiving region of a semiconductor light receiving element, and a method for manufacturing the same.

  In order to achieve the above object, the optical semiconductor device of the present invention employs the following means. An optical semiconductor device of the present invention includes a semiconductor light receiving element having a light receiving region, an electrode body on the mounting substrate, and a connection body that electrically connects the semiconductor light receiving element and the electrode body, disposed on the mounting substrate. An optical semiconductor device is assumed. In the optical semiconductor device of the present invention, the insulating wall is formed around the light receiving region of the semiconductor light receiving element. The sealing resin is in contact with the outer peripheral surface of the insulating wall and covers the semiconductor light receiving element and the mounting substrate within a range extending over the outer edge of the mounting substrate.

  The insulating wall reliably prevents the liquid resin from entering the semiconductor light receiving region when the liquid resin is filled in a range extending over the outer edge of the mounting substrate of the semiconductor device. For this reason, the problem of discoloration of sealing resin can be avoided. The sealing resin is formed, for example, by placing a mounting substrate on which a semiconductor light receiving element is disposed in a mold and filling a liquid resin into the sealing resin coating region from the outside of the mold. At this time, the insulating wall is in contact with the upper surface of the mold, and a force acts on the insulating wall and the semiconductor element from the mold. However, the semiconductor light receiving element is not damaged by providing the insulating wall with a function of relaxing the external force from the mold.

  That is, the insulating wall is desirably formed by laminating at least two types of insulators having different Young's moduli. This makes it possible to form a buffer layer using the difference in Young's modulus, and to disperse and absorb the local pressure applied to the insulating wall during resin molding in mold molding.

  Of the at least two types of insulators, the insulator having the largest Young's modulus is preferably a lower-layer insulator that is directly stacked on the semiconductor light receiving element. As a result, the upper-layer insulator is elastically deformed, and the local pressure applied to the insulating wall from the mold can be dispersed and absorbed.

  In the above, it is preferable that the minimum cross-sectional area is smaller than the lower-layer insulator among the cross-sectional areas obtained by cutting the upper-layer insulator along a plane parallel to the upper surface of the semiconductor light receiving element. This is because the stress of the insulating wall concentrates on the portion of the minimum area smaller in cross-sectional area than the lower insulator, and the stress is relieved by elastic deformation. Further, the outer edge of the lower surface of the upper insulator is formed inside the outer edge of the upper surface of the lower insulator among at least two types of insulators, so that the pressure from the mold during resin sealing can be increased. It can be dispersed from the insulator to the underlying insulator.

  A hollow portion may be formed inside the insulating wall. In this case, the upper surface of the insulating wall may be sealed or opened. Furthermore, the insulating wall may be composed of three or more layers of insulators. A hollow part may be formed in the insulator of the intermediate layer among these insulators.

  The connection body that electrically connects the semiconductor light receiving element and the electrode body is a bonding wire, and the thickness from the semiconductor light receiving element to the upper surface of the insulating wall is larger than the height from the semiconductor light receiving element to the top of the bonding wire. In the state, it is desirable that the bonding wire is sealed. Thereby, at the time of resin sealing with the metal mold | die after wire formation, resin sealing becomes possible, without a metal mold | die contacting a wire.

  Furthermore, a plurality of light receiving regions may be formed in the semiconductor light receiving element. Each of the light receiving areas has a function of reading information of each layer of the multilayer disc. As a result, an optical design necessary for the operation of the multilayer optical disc is possible, and a highly functional optical semiconductor device can be configured.

  An optical semiconductor device manufacturing method that achieves the above object employs the following means. First, a method of manufacturing an optical semiconductor device according to the present invention includes a mounting substrate including a semiconductor light receiving element having a light receiving region, an electrode body, and a connection body that electrically connects the semiconductor light receiving element and the electrode body. And a method for manufacturing an optical semiconductor device in which at least a region including a connection body among regions on a mounting substrate excluding a light receiving region of a semiconductor light receiving element is sealed with a resin. In the method for manufacturing an optical semiconductor device of the present invention, an insulating wall that blocks the resin is formed around the light receiving region of the semiconductor light receiving element, and the resin is applied to the mold in a state where the insulating wall is in contact with the inner wall of the mold. It is characterized by injecting. The region including the connection body is a region including part or all of the electrode body on the mounting substrate.

  The insulating wall is preferably made of a material having a Young's modulus smaller than that of the semiconductor light receiving element. Further, the manufacturing process of the insulating wall formed around the light receiving region of the semiconductor light receiving element forms a lower layer insulator having a Young's modulus smaller than that of the semiconductor light receiving element, and has a Young's modulus lower than that of the lower layer insulator. It may be manufactured by laminating an insulator having a small minimum cross-sectional area of a plane parallel to the upper surface on a lower insulator.

  By configuring the minimum cross-sectional area smaller than the lower-layer insulator among the cross-sectional area obtained by cutting the upper-layer insulator in a plane parallel to the upper surface of the semiconductor light-receiving element, the stress of the insulating wall concentrates on the portion of the minimum area. Stress is relieved by elastic deformation. Furthermore, of the two types of insulators of the upper layer and the lower layer, the outer edge of the lower surface of the upper layer insulator is formed inside the outer edge of the upper surface of the lower layer insulator, so that from the mold at the time of resin sealing The pressure can be distributed from the upper insulator to the lower insulator.

  A hollow portion may be formed inside the insulating wall. Accordingly, a buffer function is provided using the hollow portion, and the local pressure applied to the insulating wall from the mold can be dispersed and absorbed. The upper surface of the insulating wall may be opened. The insulating wall may be formed of three or more layers of insulators. Of these insulators, an opening may be made in an intermediate insulator, and an upper insulator may be laminated on the intermediate insulator. When the insulating wall is formed by photolithography, it is possible to form a highly accurate pattern obtained by photolithography, and it is possible to configure a high-functional and high-quality optical semiconductor device.

  The semiconductor light receiving element may have a plurality of light receiving regions, and an insulating wall may be formed around each of the light receiving regions. As a result, an optical design necessary for the operation of the multilayer optical disc is possible, and a highly functional optical semiconductor device can be configured.

  The connection body that electrically connects the semiconductor light receiving element and the electrode body is a bonding wire, and the thickness from the semiconductor light receiving element to the upper surface of the insulating wall is larger than the height from the semiconductor light receiving element to the top of the bonding wire Therefore, it is desirable that the bonding wire be sealed.

  Since the optical semiconductor device of the present invention does not form the sealing resin on the light receiving region surface of the short wavelength laser, the problem of discoloration can be avoided. Furthermore, since the insulating wall formed around the semiconductor light receiving element relaxes the external force from the mold when the optical semiconductor device is formed by resin sealing, the occurrence of cracks in the semiconductor light receiving element can be suppressed. Further, the sealing resin coats the light receiving area with high accuracy, and it is possible to configure a high-functional and high-quality optical semiconductor device. Therefore, by using the optical semiconductor device according to the present invention, it is possible to provide a high-performance and high-quality optical semiconductor device suitable for a high-function optical disc device such as an optical disc device for blue laser. In addition, the optical design necessary for the operation of the multilayer optical disc in which a plurality of light receiving regions are arranged in the same semiconductor element can be realized.

(First embodiment)
FIG. 1 shows an outline of an optical semiconductor device according to a first embodiment of the present invention. FIG. 1 (a) is a plan view and FIG. 1 (b) is a cross-sectional view taken along line AA. In the embodiment, a case will be described in which the connection body that electrically connects the semiconductor light receiving element and the electrode body is a bonding wire.

  The optical semiconductor device 1 has a configuration in which a semiconductor light receiving element 10 is mounted on a mounting substrate 3 on which bonding pads 16 as electrodes are disposed. FIG. 2 is a schematic cross-sectional view showing a manufacturing process of the optical semiconductor device, and FIG. 3 is an enlarged cross-sectional structure diagram of the semiconductor light receiving element 10 according to the present invention.

(Formation of semiconductor light receiving element)
First, the semiconductor light receiving element 10 shown in FIG. 2A is prepared. As shown in FIGS. 1A and 1B, in the semiconductor light receiving element 10, a light receiving region 12 made of a photodiode is formed on a semiconductor substrate 11 such as silicon, and a bonding wire 20 is bonded to the semiconductor light receiving element 10. A bonding pad 14 is formed for this purpose. An insulating wall 30 is formed so as to surround the light receiving region 12. Although not shown, a SiN film (silicon nitride film) that does not transmit moisture is formed on the surface of the light receiving region 12 so as to prevent moisture from entering even if the light receiving region is exposed.

  A plurality of light receiving regions 12 may be provided on one semiconductor light receiving element 10. In the example of FIG. 1, three light receiving regions are formed on one semiconductor substrate 11. Each light receiving area has a function of reading information of each layer of the multilayer disc. The reason why a plurality of light receiving regions are provided in one semiconductor light receiving element is to satisfy an optical design corresponding to a multilayer disk, and is essential for an optical disk apparatus compatible with a large capacity optical disk. The bonding pads 14 are formed in groups of four in the upper and lower regions on the left and right ends on the semiconductor light receiving element chip.

  The insulating wall 30 provided in the semiconductor light receiving element 10 in FIG. 2A is composed of two layers of insulators 31 and 32 surrounding the light receiving region 12 as shown in FIG. The insulators 31 and 32 have different Young's moduli, the lower insulator 31 is, for example, a polyimide with Young's modulus = 4.7 GPa (PI2731 manufactured by Hitachi Chemical DuPont Microsystems), and the upper insulator 32 is, for example, Young. An epoxy resist having a rate of 2.0 GPa (SU-83000, manufactured by Kayaku Microchem Corporation) can be used. The Young's modulus of the upper and lower insulators is the Young's modulus after hard baking described later.

  For the upper and lower insulators 31 and 32, a material much smaller than the Young's modulus of 190 GPa of the silicon substrate 11 representing the strength of the semiconductor light receiving element 10 is selected. In addition, since the material of the upper insulator 32 has a Young's modulus of about 0.1 to 10 GPa, the Young's modulus of the material of the lower insulator 31 is larger than that. It preferably has a value of about 0.2 to 20 GPa. These insulators are patterned on the semiconductor substrate 11 using a normal photolithography technique.

  Before the upper insulator 32 is formed on the lower insulator 31, the lower insulator 31 is hard-baked after the pattern of the lower insulator 31 is developed. The temperature at this time is a temperature at which the lower-layer insulator 31 is sufficiently cured. If the lower layer insulator 31 is cured in this manner, the lower layer insulator 31 is not dissolved by the developing solution used to form the pattern of the upper layer insulator 32, and two layers of insulators are reliably formed. Can do. The Young's modulus of the upper and lower insulators is defined by the Young's modulus after the hard baking. The lower insulator 31 was formed with a thickness of 10 μm, and the upper insulator 32 was formed with a thickness of 50 μm.

  The cross-sectional area of the insulating wall 30 in the direction along the plane of the semiconductor substrate 11 is such that the lower-layer insulator 31 is larger than the upper-layer insulator 32, and the upper-layer insulator 32 is larger than the outer edge of the lower-layer insulator 31. Form inside. Therefore, the trapezoidal insulator 32 whose upper base is shorter than the lower base as shown in FIG. In addition, as shown in FIG. 3C, the upper layer insulator 32 is formed in such a manner that the minimum sectional area 35 of the cross section parallel to the semiconductor substrate 11 is smaller than the cross sectional area cut by the plane parallel to the semiconductor substrate 11 of the lower layer insulator. It may be trapezoidal. As shown in FIGS. 3A, 3B, and 3C, the outer edge of the lower surface of the upper insulator is formed on the inner side of the outer edge of the upper surface of the lower insulator, so that the gold at the time of resin sealing The pressure from the mold can be distributed from the upper insulator to the lower insulator.

(Arrangement of semiconductor light receiving element)
Next, as shown in FIG. 2B, the semiconductor light receiving element 10 is disposed on the mounting substrate 3 by die bonding. The material of the mounting substrate 3 is not particularly limited, and epoxy resins such as glass epoxy, phenol resins, Teflon (registered trademark) resins, polyethylene resins, and the like can be suitably used.

  A mounting substrate 3 side bonding pad 16 and a lead electrode 18 for wire bonding to the bonding pad 14 on the semiconductor light receiving element 10 side are formed from the side surface to the upper surface and the lower surface of the mounting substrate 3. Since the bonding pad 16 and the extraction electrode 18 are integrally formed, it is difficult to clearly separate them. However, the bonding pad 16 is an upper surface portion of the mounting substrate 3, and the extraction electrode 18 is formed from the side surface of the mounting substrate 3. You can think of it as the part over the lower surface. Instead of the extraction electrode 18, a film in the through hole may be used as the extraction electrode. In this process, a through hole (not shown) penetrating from the front surface to the back surface is formed in the mounting substrate 3 immediately below the bonding pad 16, and a film is formed by plating inside the through hole.

(Connection of bonding wire)
Next, as shown in FIG. 2C, the bonding pads 16 on the mounting substrate 3 side and the bonding pads 14 on the semiconductor light receiving element 10 are connected by bonding wires 20. Here, since the bonding pad 14 on the pattern side of the upper insulator 32 is formed on the upper surface of the substrate 11 of the semiconductor light receiving element 10, the bonding wire 20 once rises upward from the bonding pad 14 on the semiconductor light receiving element 10 side, and then It is connected to the bonding pad 16 on the mounting substrate 3 side.

(Resin sealing)
Next, as shown in FIG. 2D, the optical semiconductor device in which the semiconductor light receiving element 10 is arranged on the mounting substrate 3 as described above is loaded into the mold 21. The mold 21 includes a lower mold 21a and an upper mold 21b. The lower mold 21a includes a recess 21c having a size that can accommodate the mounting substrate 3 without a gap and the same depth as the thickness of the mounting substrate 3, and when the mounting substrate 3 is received in the recess 21c, the outer periphery of the mounting substrate 3 The upper surface coincides with the upper surface of the recess 21c.

  A recess 21d is also formed in the upper mold 21b. The recess 21d is slightly smaller in size than the recess 21c of the lower mold 21a in a plan view (plan view from below), The depth is equal to or slightly smaller than the thickness 21 f up to the upper surface of the insulating wall 30. Near the boundary between the upper mold 21b and the lower mold 21a, there is provided a resin injection port 23 communicating with the recess 21c, from which the molten sealing resin can be poured. Yes.

  In the above configuration, when the upper mold 21b is covered in a state where the mounting substrate 3 on which the semiconductor light receiving element 10 is mounted is accommodated in the lower mold 21a, the outer peripheral portion of the mounting substrate 3 is changed by the outer peripheral portion of the upper mold 21b. At the same time, the bottom surface of the recess 21d of the upper mold comes into contact with the upper surface of the insulating wall 30, and the semiconductor light receiving element 10 and the mounting substrate 3 receive a slight stress from the upper and lower molds. However, by configuring the insulating wall 30 as described above, the stress is relieved by the insulating wall 30 and the semiconductor light receiving element 10 and the mounting substrate 3 are not subjected to stress until cracks are generated. That is, in the present embodiment, a lower layer insulator 31 is formed under the upper layer insulator 32 to form a two-layer structure, and the lower layer insulator material is composed of an upper layer insulator material and a lowermost layer semiconductor light receiving element. An intermediate Young's modulus was set. As a result, no stress is directly applied to the semiconductor light receiving element, the lower insulating material relaxes the stress, and the light receiving region 12 and the other region are separated in a liquid-tight manner.

  In this state, when molten resin is injected from the resin injection port 23, the resin is filled on the semiconductor light receiving element 10 other than the light receiving region 12 and the mounting substrate 3, and the portion of the light receiving region 12 is exposed to the outside air. In the opened state, the bonding wire 20 and the bonding pad 14 can be sealed while being protected from the outside air.

The sealing resin is resin-sealed with a thermosetting resin such as a phenol resin, a melamine resin, an epoxy resin, or a polyester resin, and then the resin is solidified.
The region to be sealed with the sealing resin is sufficient if at least the region including the connection body is sealed with the resin, but the entire region on the mounting substrate excluding the light receiving region of the semiconductor light receiving element among the regions on the mounting substrate. The region may be sealed or a part may be sealed.

(Other)
In the present embodiment, the example in which polyimide is used as the lower-layer insulator 31 and epoxy resist is used as the upper-layer insulator 32 in the insulating wall 30 surrounding the light receiving region 12 is not limited thereto. For example, an acrylic resist can be used as the upper-layer insulator 32, and any material can be selected as long as the Young's modulus and surface area of the upper and lower layers are equivalent to the above. It is. Furthermore, the insulating wall 30 is not limited to a two-layer structure, and any number of layers can be stacked as long as the relationship of increasing Young's modulus or cross-sectional area sequentially from the upper layer to the lower layer of the insulator is maintained. is there.

  The thickness from the semiconductor light receiving element 10 to the upper surface of the insulating wall 30 is preferably larger than the height from the semiconductor light receiving element 10 to the highest position of the bonding wire 20. Thus, the highest position of the bonding wire 20 is sealed with the sealing resin 24, and the object of the present application can be achieved more effectively. Patterning of at least two types of laminated insulator materials is possible using several appropriate methods, but by using photolithography capable of forming a highly accurate pattern, the purpose of the present application can be further improved. Can be achieved effectively.

(Second Embodiment)
An optical semiconductor device according to the second embodiment of the present invention will be described with reference to FIG. 4A and 4B show a cross-sectional structure of the semiconductor light receiving device according to the present embodiment, and FIG. 4C is a plan view of the semiconductor light receiving device of FIGS. 4A and 4B. FIG. 4D illustrates a photomask used in this embodiment mode. In the (embodiment of semiconductor light receiving element) step of the first embodiment, two layers of upper and lower insulators are used. In this embodiment, the opening 33 is formed in the single-layer insulating wall 30.

  A method for forming the opening 33 will be described. First, the insulating wall 30 is formed on the semiconductor substrate 11 using a normal photolithography technique. Next, an opening 33 is formed in the insulating wall 30. As shown in FIGS. 4A and 4C, the opening 33 is a cavity in which the semiconductor substrate 11 of the semiconductor light receiving element 10 is exposed at the bottom and the planar shape is circular. As shown in FIG. 4D, the openings 33 are formed by photolithography using a photomask 40 having a plurality of opening patterns 41 having a diameter of 20 μmφ at intervals of 100 μm, for example. As the material of the insulating wall 30, for example, an epoxy resist having a Young's modulus = 2.0 GPa (SU-83000, manufactured by Kayaku Microchem Corporation) used in the first embodiment is used.

  When the mounting substrate on which the semiconductor light receiving element 11 having this structure is mounted is sandwiched between the upper and lower molds 21 and sealed with resin as in the first embodiment, the plurality of openings 33 are sealed with the mold. The stress applied to the insulator 30 at the time of stopping is absorbed by elastic deformation, and the local pressure is dispersed and absorbed. Thereby, generation | occurrence | production of the crack of the board | substrate 11 of the semiconductor light receiving element 10 can be suppressed. If the size of the opening 33 is too large, it is difficult to protect the semiconductor light receiving element 10 from the pressure from the mold 21, and the adhesion to the semiconductor light receiving element 10 is also reduced. Therefore, it is desirable that the upper limit of the diameter of the opening 33 is about 50 μmφ and the lower limit is about 10 μmφ that can be patterned.

  Further, the planar shape of the opening 33 is not limited to a circular shape as long as the stress buffering function and the adhesive strength to the semiconductor light receiving element substrate 11 can be ensured, but it is uniform so that a uniform pressure distribution can be obtained. It is desirable to arrange them with the same shape of different dimensions and with an equal density on the insulator plane. Further, as shown in FIG. 4B, the combination with the first embodiment in which the insulating wall 30 has two layers or multiple layers is also effective. By forming the openings 33 in only the upper insulator 32 or the upper and lower insulators 31 and 32 of the upper and lower insulator materials, the stress applied during mold sealing can be absorbed even by elastic deformation.

(Third embodiment)
An optical semiconductor device according to the third embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a cross-sectional structure of the semiconductor light receiving element of this embodiment. A difference from the second embodiment is that the semiconductor light receiving element 10 having three insulating walls and a plurality of hollow portions 34 provided inside the insulator of the intermediate layer is formed.

  The material of each of the insulating walls 30 of the upper layer 30c, the middle layer 30b, and the lower layer 30a is the epoxy-based resist having a Young's modulus of 2.0 GPa (SU-8 3000, manufactured by Kayaku Microchem Corporation) used in the first embodiment. The range of usable Young's modulus is the same as that in the first embodiment.

  A method for forming the insulating wall 30 having the upper layer 30c, the middle layer 30b, and the lower layer 30a will be described. First, an intermediate insulator 30b is formed on a lower insulator 30a formed on the semiconductor substrate 11 in the same manner as in the first embodiment. Next, an opening is formed using the photomask 40 having the opening pattern 41 of FIG. 4D used in the second embodiment. This opening becomes a hollow portion 34.

  Next, the upper layer insulator 30c is formed. The resist used here is a dry film type resist (not shown). In the dry film type resist, the constituent material itself is the same component as the resist in the liquid state, and the material in a state where only the solvent is removed (solidified) is formed into a film. This dry film type resist is affixed on the middle layer insulator 30b. As a pasting method, a vacuum laminator was used. The thickness of each dry film type resist is 20 μm.

  By doing in this way, it is possible to affix the uppermost layer resist in a tentative manner so that the hollow portion 34 formed in the middle-layer insulator 30b is not filled. The insulator of this structure is good in appearance because it shows the same result as an insulator without a cavity.

  The resist film of the lower layer 30a and the middle layer 30b can also be formed of a dry type resist film. The insulating wall 30 having a three-layer structure shown in FIG. 5 can be formed by repeatedly performing a series of photolithography processes such as attaching a resist film and exposing and developing each insulator layer.

  As in the first embodiment, when the mounting substrate on which the semiconductor light receiving element 11 having this structure is mounted is sandwiched between the upper and lower molds 21 and sealed with resin, the stress applied to the insulating wall 30 during the mold sealing is reduced to the hollow portion. By deforming and absorbing 34, the stress can be dispersed and absorbed, and the occurrence of cracks in the semiconductor light receiving element can be suppressed.

  The plan view shape of the hollow portion 34 is preferably square or circular. The hollow structure is not limited to a three-layer structure, and a multi-layer hollow structure having three or more layers may be used. Further, it is possible to stack the openings by shifting the position of each layer.

  Insulators having different Young's moduli as in the first and second embodiments can also be used. For example, a photosensitive polyimide having a high Young's modulus (PI2731 manufactured by Hitachi Chemical DuPont Microsystems Co., Ltd.) is used for the lowermost layer 30a, and an epoxy-based permanent resist having a low Young's modulus and having a hollow structure according to this embodiment formed thereon (Chemicals) By using Microchem Co., Ltd. SU-83000), the local pressure applied to the insulator can be dispersed and absorbed.

(effect)
In the present invention, the upper surface of the insulating wall and the lower surface of the upper mold are in liquid-tight contact with each other during resin sealing, thereby preventing the sealing resin from entering the light receiving region, so that the light receiving region is not covered with the sealing resin. Therefore, the problem of discoloration of the transparent resin of the package of the semiconductor device can be avoided. Further, it is possible to suppress a problem that the element characteristics fluctuate due to a decrease in the amount of laser light that can reach the semiconductor light receiving element. The semiconductor light receiving element of the present invention has a structure in which the light receiving region is open to the outside air, but it is possible to prevent moisture from entering by forming a film that does not transmit water on the surface of the light receiving region.

  The optical semiconductor device of the present invention is useful for optical devices such as a semiconductor light receiving element and an image sensor used in an optical pickup device, and its industrial applicability is great.

It is (a) top view and (b) sectional view showing an optical semiconductor device concerning a 1st embodiment of the present invention. FIG. 6 is a process diagram in the optical semiconductor device according to the first embodiment of the present invention. It is sectional drawing which shows the light reception area | region which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the light-receiving area | region which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the light reception area | region which concerns on the 3rd Embodiment of this invention. It is sectional drawing explaining the conventional optical semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical semiconductor device 3 Mounting board 10 Semiconductor light receiving element 12 Light receiving area 14 Semiconductor light receiving element side bonding pad 16 Substrate side bonding pad 18 Lead electrode 20 Bonding wire 21a Mold lower part 21b Mold upper part 23 Resin injection port 24 Sealing resin 30 Insulation Wall 31 Insulator lower layer 32 Insulator upper layer 33 Opening 34 Hollow part

Claims (20)

A semiconductor light-receiving element having a light-receiving region disposed on the mounting substrate;
An electrode body on the mounting substrate;
In an optical semiconductor device including a connection body that electrically connects the semiconductor light receiving element and the electrode body,
An insulating wall formed around the light receiving region of the semiconductor light receiving element;
An optical semiconductor device comprising: a sealing resin that covers the outer surface of the insulating wall and covers the outer surface of the mounting substrate and covers the mounting substrate.   The optical semiconductor device according to claim 1, wherein the insulating wall is formed by stacking at least two types of insulators having different Young's moduli.   3. The optical semiconductor device according to claim 2, wherein the insulator having the largest Young's modulus among the at least two kinds of insulators is a lower-layer insulator directly stacked on the semiconductor light receiving element.   4. The optical semiconductor device according to claim 2, wherein an insulator having a minimum cross-sectional area parallel to the upper surface of the semiconductor light receiving element is made smaller than that of the lower insulator, and is laminated on the lower insulator. .   5. The optical semiconductor device according to claim 4, wherein, of the at least two types of insulators, the outer edge of the lower surface of the upper insulator is formed inside the outer edge of the upper surface of the lower insulator.   The optical semiconductor device according to claim 1, wherein a hollow portion is formed inside the insulating wall.   The optical semiconductor device according to claim 1, wherein an opening is formed on an upper surface of the insulating wall.   The optical semiconductor device according to claim 6, wherein the insulating wall is made of three or more layers of insulators, and an opening is formed on an upper surface of the intermediate layer of the insulators. The connection body is a bonding wire;
9. The bonding wire is sealed in a state where the thickness from the semiconductor light receiving element to the upper surface of the insulating wall is larger than the height from the semiconductor light receiving element to the top of the bonding wire. The optical semiconductor device described.   The optical semiconductor device according to claim 1, wherein the semiconductor light receiving element has a plurality of light receiving regions, and the insulating wall is formed around each of the light receiving regions. A mounting substrate including a semiconductor light-receiving element having a light-receiving region, an electrode body, and a connection body that electrically connects the semiconductor light-receiving element and the electrode body is disposed in a mold, and the light-receiving region of the semiconductor light-receiving element In the method of manufacturing an optical semiconductor device, a region including at least the connection body in a region on the mounting substrate excluding is sealed with a resin.
Forming an insulating wall that blocks the resin around a light receiving region of the semiconductor light receiving element;
A method of manufacturing an optical semiconductor device, comprising a step of injecting resin into the mold in a state where the insulating wall is in contact with an inner wall of the mold.   The method of manufacturing an optical semiconductor device according to claim 11, wherein the insulating wall is formed of a material having a Young's modulus smaller than that of the semiconductor light receiving element. The step of forming the insulating wall comprises
Forming a lower layer insulator having a smaller Young's modulus than the semiconductor light receiving element around the light receiving region of the semiconductor light receiving element;
12. The optical semiconductor light receiving device according to claim 11, further comprising a step of laminating an insulator having a Young's modulus smaller than that of the lower layer insulator and having a smaller minimum cross-sectional area parallel to the upper surface of the semiconductor light receiving element on the lower layer insulator. Manufacturing method of element device.   14. The method of manufacturing an optical semiconductor device according to claim 13, wherein, of the two types of insulators, an outer edge of the lower surface of the upper insulator is formed inside an outer edge of the upper surface of the lower insulator.   The method for manufacturing an optical semiconductor device according to claim 11, wherein a hollow portion is formed inside the insulating wall.   The method of manufacturing an optical semiconductor device according to claim 11, wherein an opening is formed on the upper surface of the insulating wall.   16. The insulating wall is formed of three or more insulators, an opening is formed in an intermediate insulator among the insulators, and an upper insulator is laminated on the intermediate insulator. For manufacturing an optical semiconductor device according to claim 1   The method for manufacturing an optical semiconductor device according to claim 11, wherein the insulating wall is formed by photolithography.   The method of manufacturing an optical semiconductor device according to claim 11, wherein the semiconductor light receiving element has a plurality of light receiving regions, and the insulating walls are formed around each of the light receiving regions. The connection body is a bonding wire;
20. The bonding wire is sealed in a state where the thickness from the semiconductor light receiving element to the upper surface of the insulating wall is larger than the height from the semiconductor light receiving element to the uppermost part of the bonding wire. Manufacturing method of the optical semiconductor device.

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