JP2005217027A - Package for storing optical semiconductor element and optical semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture an optical semiconductor device in which warp of an optical semiconductor element due to influence of warp of an insulating substrate is effectively prevented, in which a light reception characteristic of the optical semiconductor element is maintained, and which stably operates. <P>SOLUTION: The package for storing optical semiconductor element is provided with the insulating substrate 1 where a recessed part for storing and loading the optical semiconductor element 4 in a rectangular shape is formed on an upper face and a loading part in the rectangular shape is formed at a base of the recessed part, lead terminals 2 installed to penetrate the insulating substrate 1 and to be derived outside from inside the recessed part, and seats 7 which are fitted to both ends of a short side of the loading part and in which both ends of the short side of the optical semiconductor element 4 are bonded to upper faces. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a package for storing an optical semiconductor element and an optical semiconductor device for storing a solid-state imaging device such as a line sensor, a photodiode (PD), and an image sensor, or an optical semiconductor element having these image capturing units.

  A conventional optical semiconductor device including a solid-state imaging device such as a line sensor, a PD, an image sensor, or an optical semiconductor device having these image imaging units has a light formed by providing a concave portion for accommodating the optical semiconductor device on the upper surface of an insulating substrate. An optical semiconductor element is accommodated and mounted in a recess of a semiconductor element storage package, and the optical semiconductor element is hermetically sealed by closing the recess with a lid.

  This insulating base is usually made of a ceramic such as a quadrangle according to the shape of the optical semiconductor element, but may be made of an organic material such as a resin. For example, if the optical semiconductor element is a line sensor, it has a rectangular shape suitable for mounting an elongated rectangular line sensor.

  The lid is formed of a translucent member such as a transparent glass plate and is attached to the insulating base so as to cover the optical semiconductor element mounted on the insulating base.

  The optical semiconductor element is mounted and fixed at the central portion of the bottom surface of the recess formed on the upper surface of the insulating base, and the light receiving portion is provided at the central portion of the upper surface of the optical semiconductor element, and the electrode is provided at the outer peripheral portion. Yes.

  In addition, a lead terminal is provided so as to be led out from the inside to the outside of the concave portion of the insulating base, and the electrode of the optical semiconductor element is bonded to the portion exposed to the inside of the concave portion of the lead terminal, such as Au, Al, etc. It is electrically connected by a wire.

  The concave portion on the upper surface of the insulating base is formed by joining a light-shielding frame to the outer periphery of the flat substrate so as to surround the region where the optical semiconductor element is mounted. Moreover, the board | substrate and the frame may be integrally molded.

  An optical semiconductor device in which an optical semiconductor element is hermetically sealed in this manner is mounted and used as a component in various optical devices.

For example, if the optical semiconductor element is a line sensor, it is mounted on a circuit board constituting a device such as a scanner, a multifunction printer, or a barcode reader. Note that the alignment of the optical semiconductor device with respect to the circuit board or the like at this time is performed by aligning the outer edge portion of the optical semiconductor device with a predetermined position of the circuit substrate.
Japanese Patent Laid-Open No. 5-190879

  However, in the above-mentioned conventional optical semiconductor device, warping that protrudes upward on the insulating substrate occurs due to shrinkage when firing the ceramic constituting the insulating substrate, shrinkage when curing the organic resin, etc. When the optical semiconductor element is mounted on the insulating substrate, the optical semiconductor element may warp so as to protrude upward following the shape of the insulating substrate. In such a case, the light receiving portion on the surface of the optical semiconductor element is warped, causing distortion in the received light image, and as a result, there is a problem that the optical semiconductor element may not operate normally.

  Because of these problems, for example, when an optical semiconductor device that is hermetically sealed with a line sensor is incorporated into a scanner, multifunction printer, barcode reader, etc., malfunctions may occur in detection by the line sensor. Had occurred. In particular, when the optical semiconductor element has a rectangular shape such as a line sensor, the warp of the insulating substrate is increased in the long side direction, and thus the distortion of the received light image becomes significant.

  Accordingly, the present invention has been completed in view of the above-described conventional problems, and its purpose is to have a high dimensional accuracy, and particularly to prevent an optical semiconductor element having a rectangular shape from causing problems such as warping of a light receiving portion. An object of the present invention is to provide an optical semiconductor element housing package and an optical semiconductor device having good characteristics such as light receiving characteristics that can be hermetically sealed.

  The package for housing an optical semiconductor element of the present invention includes an insulating base having a concave portion for accommodating and mounting a rectangular optical semiconductor element on the upper surface and a rectangular mounting portion formed on the bottom surface of the concave portion, Lead terminals provided so as to pass through the insulating base and lead out from the inside to the outside of the recess, and attached to both ends on the short side of the mounting portion, and on the upper surface of the optical semiconductor element And a pedestal to which both ends of the short side are joined.

  The optical semiconductor element storage package of the present invention is preferably characterized in that the difference in height between the pedestals joined to both ends on the short side is less than 0.1 mm.

  In the optical semiconductor element storage package of the present invention, preferably, the pedestal is attached at a position of 0.5 to 1 mm from the inner surface of the recess.

  An optical semiconductor device according to the present invention includes an optical semiconductor element storage package having the above-described configuration according to the present invention, and is accommodated in the recess, and the lower surfaces of both end portions on the short side are bonded to the upper surface of the pedestal. A rectangular optical semiconductor element electrically connected to a lead terminal, and a translucent lid attached so as to close the concave portion on the upper surface of the insulating base. Is.

  According to the optical semiconductor element storage package of the present invention, pedestals are provided at both ends on the short side of the mounting portion on the bottom surface of the recess, and both ends on the short side of the optical semiconductor element are joined to the top surface of the pedestal. Therefore, the optical semiconductor element is not placed directly on the bottom surface of the concave portion, and as a result, even if the bottom surface of the concave portion of the insulating base is warped, the optical semiconductor element follows the warpage of the bottom surface of the concave portion. There is no warping. Therefore, it is possible to provide an optical semiconductor device that can be mounted on an insulating substrate while maintaining the parallelism of the optical semiconductor element, and that the optical semiconductor element can operate stably over a long period of time.

  For example, when the insulating substrate is made of ceramics, it is possible to effectively absorb the warp of the insulating substrate generated during the firing of the ceramic and to horizontally mount and hold the optical semiconductor element without being affected by the warp. In addition, even when the insulating base is made of an organic material such as a resin, the short side of the optical semiconductor element is provided at each end on the short side of the mounting portion, even when a relatively large warp occurs due to the thermal history of the resin. By providing a pedestal for joining and holding both end portions on the side, the optical semiconductor element can be mounted horizontally without warping. As a result, it is possible to provide a package for housing an optical semiconductor element that is excellent in positional accuracy for mounting the optical semiconductor element. In addition, the optical semiconductor device can be manufactured with high yield and low cost.

  The optical semiconductor element storage package of the present invention preferably has a height difference due to contraction of the pedestal itself because the difference in height between the pedestals joined to both ends on the short side is less than 0.1 mm. Variation, deformation, and the like can be minimized, and the tilt of the optical semiconductor element due to warpage of the bottom surface of the recess can be effectively prevented.

  In the optical semiconductor element storage package of the present invention, preferably, the pedestal is attached at a position of 0.5 to 1 mm from the inner side surface of the recess, so that the optical semiconductor element and the insulating substrate are brought into contact with each other. It is possible to achieve prevention and downsizing in the long side direction.

  In addition, the pedestal can effectively prevent the optical semiconductor element from being tilted due to the deformation due to the contraction of the bottom surface of the concave portion of the insulating substrate, or the deformation accompanying the thermal history, and the optical semiconductor device can be miniaturized, A circuit board constituting a device such as a scanner, a multi-function printer, or a barcode reader incorporating an optical semiconductor device can be downsized.

  An optical semiconductor device according to the present invention includes an optical semiconductor element storage package having the above-described configuration according to the present invention, and is accommodated in a recess, and the lower surfaces of both end portions on the short side are joined to the upper surface of the pedestal, and the electrodes serve as lead terminals. Since the rectangular optical semiconductor element electrically connected and the translucent cover attached so as to close the concave portion on the upper surface of the insulating base, the rectangular optical semiconductor element is provided. It is possible to provide an optical semiconductor device with good characteristics such as light receiving characteristics that can effectively prevent warpage or the like from occurring in the light receiving portion.

  The optical semiconductor device of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of an optical semiconductor device using an optical semiconductor element housing package of the present invention. In FIG. 1, 1 is an insulating substrate, 2 is a lead terminal, 3 is a translucent lid, 4 is an optical semiconductor element, and 7 is a pedestal. The insulating semiconductor 1, the lead terminal 2, the lid 3, the optical semiconductor element 4 and the base 7 mainly constitute an optical semiconductor device 8.

  In addition, 1a is a resin bonding material for bonding the optical semiconductor element 4 to the base 7, and 1b is a resin bonding material for bonding the insulating substrate 1 and the lid 3 together.

  The insulating substrate 1 of the present invention is made of an insulating material such as an alumina sintered body or a glass ceramic sintered body. For example, if the insulating base 1 is made of an alumina sintered body, the raw material powder such as alumina is used as an organic solvent or resin. A plurality of green sheets are produced by forming into a sheet shape together with the binder, and the green sheets are appropriately punched to form a predetermined shape, and are fired at a high temperature.

  The insulating substrate 1 may be formed of a resin material such as an epoxy resin, a glass epoxy resin, or polyimide.

  On the upper surface of the insulating substrate 1, a recess for receiving and mounting the optical semiconductor element 4 is provided. If the insulating substrate 1 having such a recess is made of, for example, an alumina sintered body, a part of a ceramic green sheet (hereinafter also referred to as a green sheet) is punched into a frame shape, It is formed by laminating a frame-like green sheet on a green sheet and firing it integrally. Alternatively, it may be formed by bonding a frame-shaped ceramic to the upper surface of a separately manufactured plate-shaped ceramic using crystalline glass or the like.

  If the insulating substrate 1 is made of an epoxy resin, it is molded by a transfer molding method, an injection molding method, or the like using a mold that can mold an uncured epoxy resin into the shape of the predetermined insulating substrate 1. Is formed. In this case, the flat plate portion and the square frame portion may be separately formed, and then the concave portion may be formed by joining the frame portion to the outer peripheral portion of the upper surface of the substrate portion. Alternatively, it may be integrally formed using a mold in which a recess is formed.

  In the present invention, a rectangular mounting portion is formed on the bottom surface of the concave portion of the insulating base 1, and pedestals 7 are attached to both end portions on the short side of the mounting portion. The pedestal 7 has a function of supporting and fixing the optical semiconductor element 4, and both ends on the short side of the optical semiconductor element 4 are bonded to the upper surface thereof.

  The base 7 for mounting the optical semiconductor element 4 may be made of ceramic, resin, or metal. The pedestal 7 is formed by integrally molding with an insulating base 1 made of ceramics, integrally molding with an insulating base 1 made of resin, or a square columnar pedestal 7 made of ceramics or a square columnar pedestal 7 made of resin at a predetermined position. You may join using a joining material etc.

  According to the optical semiconductor device 8 of the present invention, the mounting portion is provided with the pedestal 7 that holds only both ends on the short side of the optical semiconductor element 4, and the optical semiconductor element 4 is mounted on the pedestal 7 and bonded and fixed. As a result, warpage caused by thermal shrinkage during firing of ceramics, which occurs when the insulating substrate 1 is made of ceramic, and time-dependent change of the resin due to moisture absorption and thermal history of the resin, which occurs when the insulating substrate 1 is made of resin. Even if a relatively large warp occurs due to the above, it is possible to mount the optical semiconductor element 4 with good leveling accuracy.

  As a result, it is possible to effectively prevent distortion in the received light image in the light receiving portion of the optical semiconductor element 4 and provide an optical semiconductor element housing package with excellent mounting accuracy of the optical semiconductor element 4. In addition, the optical semiconductor device 8 can be manufactured with good yield and low cost.

  In the present invention, the lead terminal 2 is provided so as to be led out from the inside to the outside of the concave portion of the insulating base 1. The lead terminal 2 is made of an iron-based alloy such as an iron-nickel-cobalt alloy or an iron-nickel alloy, or copper or a copper-based alloy. If the lead terminal 2 is made of, for example, an iron-nickel-cobalt alloy, the lead terminal 2 is formed by punching or etching the iron-nickel-cobalt alloy plate material and processing it into a predetermined size and shape. Is done.

  In order to provide the lead terminal 2 so as to be led out from the inside to the outside of the recess, when the insulating base 1 is made of ceramics, for example, a lead frame formed by connecting one end of a plurality of lead terminals 2 with a frame, A method of bonding between a plate-shaped ceramic substrate and a frame-shaped ceramic substrate using crystalline glass (borosilicate glass) or the like can be used.

  Further, when the insulating base 1 is made of resin, for example, a lead frame formed by connecting one end portions of a plurality of lead terminals 2 with a frame is exposed to the outside of the recess (outside the side surface of the insulating base 1), and The ends of the lead terminals 2 that are not connected by the frame are exposed in the recesses, and the insulating base 1 is set in a mold for molding, and an uncured resin that becomes the insulating base 1 is placed. A method such as heat-curing integrally with the lead frame can be used. In these cases, after the lead terminal 2 is provided on the insulating base 1, the frame is cut and removed.

  The insulating base 1, the lead terminal 2 and the pedestal 7 mainly constitute an optical semiconductor element storage package according to the present invention. The optical semiconductor element 4 is accommodated in the recess, and the optical semiconductor element 4 is short. Both end portions on the side are positioned and placed on the pedestal 7 and bonded and fixed via a resin bonding material 1a made of a resin such as epoxy resin, and the electrode of the optical semiconductor element 4 is placed in the recess of the lead terminal 2 The exposed portion is electrically connected via an electrical connection material (not shown) such as a bonding wire, and then a translucent lid 3 is provided on the upper surface of the insulating base 1 so as to close the recess. The optical semiconductor device 8 is manufactured by bonding and attaching via the resin bonding material 1b.

  In the optical semiconductor element storage package and the optical semiconductor device 8 of the present invention, the pedestal 7 is more preferable as its volume is larger in order to firmly hold and join the optical semiconductor element 4, but if it is too large, It becomes easy to be influenced by the warp of the insulating substrate 1, and the optical semiconductor element 4 is warped. Therefore, the size of the base 7 is preferably set such that the width of the base 7 is in the range of A + 0.6 mm to A + 1.5 mm, where A is the width on the short side of the optical semiconductor element 4. Further, assuming that the length in the long side direction of the electrode and the wiring part excluding the light receiving part on the long side of the optical semiconductor element 4 is B, the length in the long side direction of the base 7 is in the range of B + 0.6 mm to B + 1.5 mm. It is preferable that This is because the pedestal 7 cannot be placed directly under the light receiving portion of the optical semiconductor element 4 so as not to affect the light receiving characteristics of the optical semiconductor element 4, and therefore the pedestal 7 is provided directly under the electrode and wiring portion. This is because the length of the electrode and the wiring portion in the long side direction determines the length of the base 7.

  In addition, as a method of joining the base 7 to the bottom surface of the concave portion of the insulating base 1, for example, a method such as adhesion with an adhesive can be used. Further, when the insulating base 1 made of ceramics, resin, or the like is formed, a method such as forming the plate-like body that becomes the insulating base 1 and the base 7 together can be used.

  In the present invention, the pedestal 7 can have a columnar shape such as a columnar shape, a prismatic shape, or various shapes such as a cube and a rectangular parallelepiped. Good shape.

  In the optical semiconductor element housing package and the optical semiconductor device 8 of the present invention, it is preferable that the difference in height between the pedestals 7 bonded to both ends on the short side is less than 0.1 mm. If the difference in height between the pedestals 7 joined to both ends on the short side is set to be less than 0.1 mm, height variation due to contraction of the pedestal 7 itself, deformation, etc. can be minimized, Inclination of the optical semiconductor element 4 due to warping of the bottom surface can be effectively prevented.

  In order to make the difference in height of the pedestal 7 at both ends on the short side less than 0.1 mm, for example, when the pedestal 7 is joined to the mounting portion via the resin joining material, before the resin joining material is cured. In addition, a method such as pressing the pedestal 7 from above with a pressure jig and adjusting the height of the pedestal 7 can be used.

  In the optical semiconductor element housing package and the optical semiconductor device 8 of the present invention, the pedestal 7 is preferably attached at a position of 0.5 to 1 mm from the inner surface of the recess. In this case, contact between the optical semiconductor element 4 and the insulating substrate 1 can be prevented, and downsizing in the long side direction can be realized. In addition, the optical semiconductor element 4 can be effectively prevented from being inclined due to the deformation of the base 7 due to the contraction of the bottom surface of the concave portion of the insulating substrate 1 or the deformation due to the thermal history, and the optical semiconductor device 8 can be reduced in size. Circuit boards constituting devices such as scanners, multifunction printers, and barcode readers incorporating optical semiconductor devices can be miniaturized.

  In addition, the pedestal 7 being at a position of 0.5 to 1 mm from the inner surface of the recess means that the interval (shortest distance) between the pedestal 7 and the inner surface of the recess is 0.5 to 1 mm. .

  The pedestal 7 is preferably made of a material having elasticity, such as a resin, in order to make it difficult to transmit the influence of the warp of the insulating base 1 to the optical semiconductor element 4. Further, a step is provided so that the outside of the upper surface of the pedestal 7 in the long side direction is lowered, and the volume of the resin bonding material is increased at the step, so that when the insulating base 1 is warped upward, the pedestal 7 It is possible to prevent the outer side joining in the long side direction from deteriorating.

  The lid 3 is preferably made of glass such as soda glass, plastic, sapphire (alumina single crystal), quartz, or the like in terms of high light transmittance, ease of manufacture, chemical stability, strength, and the like. .

  The optical semiconductor element 4 includes a solid-state imaging element such as a PD, a line sensor, an image sensor, a CCD (Charge Coupled Device), an EPROM (Erasable Programmable ROM), or an optical semiconductor element 4 having these imaging units.

  Further, when the resin bonding material 1a for bonding the insulating substrate 1 and the optical semiconductor element 4 is made of an ultraviolet curable resin, a heating process for bonding is omitted as compared with the case of using a thermosetting resin. Since the warp due to the difference in thermal expansion coefficient between the base 1 and the optical semiconductor element 4 does not occur in the insulating base 1 and no distortion occurs in the received light image, the optical semiconductor device 8 having higher reliability is manufactured. Can be preferred.

  The resin bonding material 1b for bonding the insulating substrate 1 and the lid 3 is preferably made of an ultraviolet curable resin because it can be cured at room temperature and has little influence on the optical semiconductor element 4. In this case, it is not necessary to leave in the oven or the like for a long time until the optical semiconductor element 4 is mounted on the mounting portion and the lid 3 is attached and sealed. As a result, dust, foreign matter, and the like are not mixed in the optical semiconductor device 8, and the manufacturing yield can be dramatically improved.

  In addition, the ultraviolet curable resin 1b such as an epoxy resin may be mixed with a dark pigment or dye such as black, brown, dark green, or dark blue in order to block extraneous light from entering.

  Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.

  A concave portion is provided on the upper surface of the insulating base made of an aluminum oxide sintered body, and a mounting portion for the optical semiconductor element is formed on the bottom surface of the concave portion. A base made of epoxy resin is formed with a resin bonding material at the position shown in Table 1. The optical semiconductor element storage package was prepared by attaching.

  The mounting portion of the optical semiconductor element indicates a region where the optical semiconductor element is mounted at the central portion of the bottom surface of the recess of the insulating base, and is a rectangle having a length of 51.5 mm and a length of the long and short sides of 1.75 mm. Is.

  The height of the pedestal is measured by measuring the depth of focus with a microscope, and a difference in height of the pedestal of 0 mm means a height difference that is not detected by the measurement method.

  The concave portion has a rectangular parallelepiped shape and has a rectangular shape with a short side length of 4 mm and a long side length of 51.5 mm in plan view, and is led out from the inner side to the outer side of each long side. Thus, 11 lead terminals made of iron-nickel-cobalt alloy were led out for each side.

  On this pedestal, both ends on the short side of the rectangular line sensor (0.8 mm × 48 mm) are joined with epoxy resin, and the concave portion is closed with a glass lid to produce an optical semiconductor device. A test was conducted to determine whether the optical semiconductor element can receive light normally.

The light receiving state was confirmed by applying a predetermined light to the optical semiconductor element, measuring the output voltage with respect to the input light amount using an electric tester, and obtaining photoelectric conversion characteristics. The results are shown in Table 1.

  As can be seen from the results in Table 1, when the difference in height of the pedestal is 0.1 mm or more, the height tolerance due to the shrinkage of the pedestal itself, the dimensional tolerance due to deformation, etc. increases, and the optical semiconductor accompanying warping of the bottom surface of the recess The tilt of the element could not be prevented. Further, in this case, since the deformation of the pedestal increases during long-term use, it is difficult to reliably keep the light receiving surface of the optical semiconductor element horizontal for a long time. Further, since the height of the pedestal is high, it is difficult to reduce the height of the optical semiconductor element storage package.

  In addition, when the pedestal is located at a position less than 0.5 mm from the inner surface of the recess, when the optical semiconductor element is mounted on the pedestal, the optical semiconductor element is not in contact with the insulating substrate portion on the inner surface of the recess due to the influence of mounting accuracy or the like. As a result, there was a problem that the optical semiconductor element was chipped or scratched to make the expensive optical semiconductor element defective. When the position of the pedestal exceeds 1 mm from the inner surface of the recess, the pedestal tends to tilt with the deformation of the insulating substrate, and the light receiving state tends to deteriorate.

  In addition, as the length of the insulating base in the long side direction increases, the degree of deformation of the insulating base increases, and the base itself tends to tilt with the deformation of the insulating base, and the light receiving state tends to deteriorate. It is disadvantageous to make the circuit board that constitutes devices such as a scanner, a multifunction printer, and a barcode reader incorporating an optical semiconductor device small.

  On the other hand, in the range of the present invention in which the difference in height of the pedestal is less than 0.1 mm and the distance from the pedestal to the inner surface of the recess is 0.5 to 1 mm, distortion occurs in the light receiving state. In addition, the light receiving accuracy of the optical semiconductor device was good.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulating base | substrate 1a ... Resin bonding material 1b ... Resin bonding material 2 ... Lead terminal 3 ... Translucent cover body 4 ... Optical semiconductor element 7 ... Base 8 ...・ Optical semiconductor devices

Claims (4)

A recess for accommodating and mounting a rectangular optical semiconductor element is formed on the top surface, and an insulating substrate having a rectangular mounting portion formed on the bottom surface of the recess, and the inside of the recess through the insulating substrate Lead terminals provided so as to be led out to the outside, and pedestals that are respectively attached to both ends on the short side of the mounting portion and that both ends on the short side of the optical semiconductor element are joined to the upper surface And a package for storing an optical semiconductor element. 2. The optical semiconductor element housing package according to claim 1, wherein a difference in height between the pedestals respectively joined to both ends on the short side is less than 0.1 mm. 3. The optical semiconductor element storage package according to claim 1, wherein the pedestal is attached at a position of 0.5 to 1 mm from the inner surface of the recess. The optical semiconductor element housing package according to any one of claims 1 to 3, wherein the optical semiconductor element housing package is housed in the recess, and the lower surfaces of both end portions on the short side are joined to the upper surface of the pedestal, and an electrode is the lead A light comprising: a rectangular optical semiconductor element electrically connected to a terminal; and a translucent cover attached to the upper surface of the insulating base so as to close the recess. Semiconductor device.

Images