JP2010045107A - Method for manufacturing optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical semiconductor device manufacturing method capable of easily manufacturing a high-resolution and high-performance optical semiconductor device without using a mold.
A light-emitting element 2 and a light-receiving element 3 are mounted on a collective substrate 1, the electrodes are connected to electrode terminals on the collective substrate 1, the entire surface is sealed with a translucent resin layer 5, and light is emitted. A part of translucent resin layer 5 is cut so that the surface and the light receiving surface are the upper surface of convex portion 5a to form convex portion 5a, and between light emitting element 2 and light receiving element 3, and the light emitting element A groove reaching the substrate is formed in the translucent resin layer 5 around the light receiving element, and the light-shielding resin is coated so as to cover the periphery of the translucent resin layer 5 including the inside of the groove, the light-shielding groove 5b, and the separation groove 5c. Cover with layer 6. Then, after the upper surface of the light-shielding resin layer 6 is ground so that the protruding surface of the convex portion 5a of the translucent resin layer is exposed, the light-shielding resin layer 6 is separated into individual pieces.
[Selection] Figure 1

Description

  In the present invention, the light emitting element and the light receiving element are arranged with the light emitting surface and the light receiving surface aligned in the same direction, and the light emitted from the light emitting element is reflected by the object and detected by the light receiving element, The present invention relates to a method of manufacturing an optical semiconductor device that detects an object. More specifically, the present invention relates to a method of manufacturing an optical semiconductor device that can easily manufacture a high-resolution optical semiconductor device that can accurately read a fine pattern such as a barcode without using a mold.

An optical semiconductor device called a so-called photoreflector, in which a conventional light emitting element and light receiving element are arranged in the same direction and the light emitted from the light emitting element is reflected by an object and detected by the light receiving element, is produced to some extent. In the case of performing, the double mold method is used. That is, a light emitting element and a light receiving element are die-bonded on a substrate, and each electrode of the light emitting element and the light receiving element is connected to an electrode terminal (wiring) on the substrate by wire bonding or the like and sealed with a translucent resin. Therefore, a primary mold is performed. Then, except the light emitting surface and the light receiving surface of the light emitting element and the light receiving element, the periphery of the translucent resin layer covering the light emitting element and the light receiving element is molded again with a light shielding resin (secondary mold). ), Light from the outside or light from a light emitting element other than that reflected by the object is not directly incident on the light receiving element. At this time, a photo reflector that requires high resolution employs a structure in which a light shielding wall is formed between the light reflectors so that light from the light emitting elements does not directly reach the light receiving elements (see, for example, Patent Document 1).
JP 2006-38572 A

  As described above, when the double mold method is used, two types of molds are required for one type of product, and in the case of mass production with a small number of products, it is possible to recover the mold production costs. However, in the case of high-mix low-volume production, there is a problem that the mold cost increases and the cost of the optical semiconductor device (photo reflector) increases.

  For example, an optical semiconductor device such as a photoreflector that simply detects the presence or absence of an object does not require so much precision regarding the positional relationship between the light emitting element and the light receiving element when manufacturing the optical semiconductor device. In optical semiconductor devices that require high resolution, such as fine bar code detection, the influence of noise is eliminated as much as possible, and the light reflected by the object is reliably received by the light receiving element. This is very important, and it is necessary to manufacture the product with considerable precision so that noise and the like do not enter. A high-resolution optical semiconductor device that requires such precision is preferably manufactured by a double molding method by mold molding, but the size of the outer shape differs slightly depending on the intended use, and the light emitting surface and light receiving surface If there is a difference in the presence or absence of lens formation, the mold must be changed one by one. As described above, the double mold method requires two molds for one product. Since the mold cost is very expensive, there is a problem that the cost is very high in the case of multi-product small-volume production.

  The present invention has been made to solve such a problem, and provides an optical semiconductor device manufacturing method capable of easily manufacturing a high-resolution and high-performance optical semiconductor device without using a mold. The purpose is to provide.

  A method of manufacturing an optical semiconductor device according to the present invention includes mounting a plurality of sets of light emitting elements and light receiving elements on a collective substrate, connecting electrodes of the light emitting elements and light receiving elements to electrode terminals on the collective substrate, A plurality of sets of light emitting elements and light receiving elements are sealed with a translucent resin layer so as to be integrally covered, and the light emitting surface and the light receiving surface of the set of light emitting elements and light receiving elements are formed in a convex protruding shape. While cutting a part of the translucent resin layer, between the light emitting element and the light receiving element of each set of the light emitting element and the light receiving element, and at the boundary portion of each set of the light emitting element and the light receiving element After forming a groove reaching the substrate in the light transmitting resin layer, the light transmitting resin layer is covered so as to cover the periphery of the light transmitting resin including the inside of the groove, and the convexity of the light transmitting resin layer is formed. The protruding surface of the mold is exposed The upper surface of the light shielding resin layer is ground, and then the light shielding resin layer at the boundary of each set of the light emitting element and the light receiving element is disposed on the side wall of each pair of the light emitting element and the light receiving element. It is characterized by being cut into pieces by cutting so as to remain.

  Here, the collective substrate means a large substrate on which a plurality of sets of light emitting elements and light receiving elements can be formed simultaneously. As the light emitting element and the light receiving element, a bare chip formed from a semiconductor wafer is generally used, but it may be packaged in the form of an element such as a chip type element. In short, it is sufficient if it is formed so as to emit or receive light, and the shape of its appearance is not limited. The light receiving element means any element other than a photodiode and a phototransistor as long as it can detect light. Further, the electrode terminal means a portion that relays the electrodes of the light emitting element and the light receiving element (including a lead in the case of the element), and includes a wiring and the like.

  According to the present invention, a light emitting element and a light receiving element are mounted on a collective substrate (die bonding), and the electrode is connected to an electrode terminal (wiring) formed on the collective substrate, and then the whole is made of a translucent resin. Since the light emitting surface of the light emitting element and the light receiving surface of the light receiving element are the upper surfaces of the narrow convex portions, and the side walls of the convex portions are covered with a light shielding resin. The light emitted from the light emitting element is emitted only from the upper surface through the convex part, and only the reflected light from the object is received by the light receiving element, and the light from the light emitting element directly enters the light receiving element, or the disturbance light Can be prevented from entering the light receiving element directly, and the pattern of the object can be accurately recognized without noise. Moreover, a set of light emitting elements and light receiving elements is continuously arranged on the collective substrate, and generally, after die bonding and wire bonding, a translucent resin is poured over the entire surface of the collective substrate and sealed, After that, a part of the translucent resin is ground by grinding to form a convex part, and the light-shielding resin is poured into the whole again, and the upper surface of the light-shielding resin is ground so that the upper surface of the convex part is exposed. Therefore, a very precise optical semiconductor device (photo reflector) can be manufactured only by pouring and grinding the resin twice.

  As a result, for example, a high-resolution optical semiconductor device that can accurately read a fine pattern such as a barcode can be manufactured at a very low cost without being manufactured by a double mold using a mold. Therefore, it is possible to immediately cope with a specification change by the user, and it is possible to produce a variety of products in a small amount and in a short period of time even in the production of small quantities.

  Next, a method for manufacturing an optical semiconductor device (photo reflector) of the present invention will be described with reference to the drawings. FIG. 1 is a perspective explanatory view showing a manufacturing process of one photo reflector according to an embodiment of the present invention. FIG. 2 shows a case where a plurality of photo reflectors are manufactured on a collective substrate to be actually manufactured. An illustration is shown.

  First, as shown in FIG. 1A, a plurality of sets of light emitting elements 2 and light receiving elements 3 are mounted on the collective substrate 1, and electrodes (not shown) of the light emitting elements 2 and the light receiving elements 3 are mounted. It connects with an electrode terminal (wiring) (not shown) on the collective substrate 1. The collective substrate 1 is made of, for example, an organic substrate, and is connected to an electrode terminal or wiring to be connected to an electrode of the light emitting element 2 or the light receiving element 3 (or an electrode terminal or lead of the element in the case of an element), or to an external circuit. Electrode terminals and wiring to be formed are formed, which is a large substrate for manufacturing a plurality of photo reflectors together. Actually, as schematically shown in FIG. 2, a set of bare chips of the light emitting element 2 and the light receiving element 3 is die-bonded on the collective substrate 1 in a matrix, and one electrode of each is attached to the collective substrate 1. The other electrode is connected to an electrode terminal (wiring) (not shown) by bonding the wire 4.

  Next, as shown in FIG. 1B, the light emitting element 2, the light receiving element 3, and the wire 4 are covered with a translucent resin layer 5. As the translucent resin, for example, an epoxy resin can be used. As shown in FIG. 2, the translucent resin layer 5 is formed with a dam 7 having a height of, for example, about 0.5 mm around the collective substrate 1. It becomes flat in height and the translucent resin layer 5 is formed.

  Next, as shown in FIG. 1C, the light-emitting element 2 and the light-receiving element of the translucent resin layer 5 so that the light-emitting surface and the light-receiving surface of the light-emitting element 2 and the light-receiving element 3 are the upper surface of the convex portion 5a. Grind both sides with, for example, a flat end mill 8 so as to remain at a height of, for example, about 0.2 to 0.3 mm along the direction connecting the light emitting element 2 and the light receiving element 3 to the upper part of the element 3. The convex part 5a is formed.

  Thereafter, as shown in FIG. 1D, between the light emitting element 2 and the light receiving element 3 and around the set of the light emitting element 2 and the light receiving element 3 (not shown in FIG. 1D) (FIG. 2). A groove reaching the substrate 1 is formed in the translucent resin layer 5 in the boundary portion of each set of the light emitting element 2 and the light receiving element 3 shown in FIG. A groove between the light emitting element 2 and the light receiving element 3, that is, the light shielding groove 5b, is a groove for forming a light shielding wall between the light emitting element 2 and the light receiving element 3, and has a width of about 0.2 to 0.3 mm. In the groove around the element, that is, the separation groove 5c, the thickness removed by cutting for separation into individual pieces, and the light-shielding resin layer 6 embedded in the groove remains around each photo reflector after cutting. Such a width, that is, a width of about 0.3 to 0.6 mm is formed. The light shielding grooves 5b and the separation grooves 5c are formed deep so as to reach about half the thickness of the collective substrate 1.

  Next, as shown in FIG. 1E, the light-shielding resin layer 6 covers the periphery of the translucent resin 5 including the inside of the light-shielding grooves 5b and the separation grooves 5c. The light-shielding resin layer 6 is also formed in the state of the large collective substrate 1 shown in FIG. 2 by forming another dam (not shown) on the outer periphery of the dam 7, and in the same manner as the light-transmitting resin layer 5 described above. By coating the light-shielding resin, it flows into the light-shielding grooves 5b and the separation grooves 5c, fills the recessed portions, and flattens the surface. As this light-shielding resin, for example, epoxy resin mixed with light blocking powder such as carbon black can be used. The dam (not shown) is slightly cut from the transmissive resin layer 5 because the dam 7 used when applying the translucent resin is cut when the light shielding groove 5b and the separation groove 5c are formed. When the high light-shielding resin layer 6 is formed, it is easier to flatten the surface. Therefore, the outer periphery of the dam 7 is formed to be slightly higher (about 0.1 to 0.2 mm) than the dam 7. Is preferred.

  Thereafter, as shown in FIG. 1 (f), the upper surface of the light-shielding resin layer 6 is ground and flattened by, for example, a flat end mill, and the upper surface of the convex portion 5 a of the translucent resin layer 5 is flattened. Expose. Thereafter, the light-shielding resin layer 6 remains on the side wall of each pair (photoreflector) of the light emitting element 2 and the light receiving element 3 at the boundary portion (line S shown in FIG. 2) of each pair of the light emitting element 2 and the light receiving element 3. Cut into pieces and cut into pieces. As a result, the light-emitting surface and the light-receiving surface of the light-emitting element 2 and the light-receiving element 3 are the upper surfaces of the convex portions 5a formed by the translucent resin layer 5 on the light-emitting element 2 and the light-receiving element 3, and the others A photo reflector covered with a light-shielding resin layer 6 is obtained between the outer periphery of the light-emitting element and between the light-emitting element 2 and the light-receiving element 3.

  As described above, according to the present invention, the resin is applied twice for the translucent resin layer 5 and the light-shielding resin layer 6, and the grinding for forming the convex portion 5a of the translucent resin layer 5 is performed. And only by performing two times of grinding for flattening the upper surface of the light-shielding resin layer 6 and exposing the upper surface of the convex mold part 5a, without using a mold for double molding, A photo reflector having a precise dimensional configuration can be obtained. On the other hand, according to this photoreflector, the light emitted from the light emitting element 2 passes through the convex portion 5a, is emitted from the upper surface thereof, and is received when receiving the light reflected by the object and returning. Since it is formed so that only the light incident from the upper surface of the convex portion 5a on the element 3 can be received, the light from the light emitting element 2 reaches the light receiving element 3 directly and becomes noise, or external light directly It is suppressed that the light receiving element 3 enters and becomes noise, and an optical semiconductor device (photo reflector) with very high resolution is obtained.

  When reading a bar code using such an optical semiconductor device, scanning the bar code in a direction perpendicular to the extending direction of the convex part 5a makes the convex part 5a narrower. A fine barcode can be read.

It is a manufacturing-process figure which shows one Embodiment of the manufacturing method of the optical semiconductor device of this invention. FIG. 2 is an explanatory diagram of an example of manufacturing a plurality of optical semiconductor devices of FIG. 1 simultaneously using a large collective substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collective substrate 2 Light emitting element 3 Light receiving element 4 Wire 5 Translucent resin layer 5a Convex part 5b Light shielding groove 5c Separation groove 6 Light shielding resin layer 7 Dam 8 End mill S Cutting line

Claims (1)

  A plurality of sets of light emitting elements and light receiving elements are mounted on the collective substrate, electrodes of the light emitting elements and light receiving elements are connected to electrode terminals on the collective substrate, and the plural sets of light emitting elements and light receiving elements are integrated. Sealing with a translucent resin layer so as to cover, and cutting a part of the translucent resin layer so that the light emitting surface and the light receiving surface of the set of the light emitting element and the light receiving element have a convex protruding shape And a groove reaching the substrate between the light emitting element and the light receiving element of each set of the light emitting element and the light receiving element and between the light emitting element and the light receiving element and at a boundary portion of each set of the light emitting element and the light receiving element. Then, the light-transmitting resin layer is covered so as to cover the periphery of the translucent resin including the inside of the groove, and the convex protruding surface of the translucent resin layer is exposed. Grinding the upper surface of the light shielding resin layer, The light-shielding resin layer at the boundary portion of each set of the light-emitting element and the light-receiving element is separated into pieces by cutting so that the light-shielding resin layer remains on the side wall of each set of the light-emitting element and the light-receiving element. An optical semiconductor device manufacturing method.

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