JP2009088435A - Photoreflector, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoreflector equipped with a shading member which can prevent leakage of light from a light emitting element to a light receiving element on the surface of a substrate even if the substrate for mounting the light emitting element and the light receiving element is thin. <P>SOLUTION: The photoreflector 30 including a substrate 32 on which an electrode pattern on the light emission side and an electrode pattern on the light reception side are formed, a light emitting element 42 and a light receiving element 44 arranged, respectively, on the light emission side electrode pattern and the light reception side electrode pattern, a sealing member 46 on the light emission side and a sealing member 48 on the light reception side for sealing the light emitting element 42 and the light receiving element 44, respectively, from above with translucent resin, and a shading frame 62 partitioning between the sealing members 46 and 48 is provided, on the upper surface of the substrate 32, with a shading layer 61 which covers the electrode pattern on the light emission side and the electrode pattern on the light reception side, respectively, and to which the lower end of the shading frame 62 is stuck tightly with no gap. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photo reflector that includes a light emitting element and a light receiving element and detects an object to be detected in a non-contact manner, and a method for manufacturing the photo reflector.

  Conventionally, as this type of photo reflector, those shown in FIGS. 9 and 10 are known. The photo reflector 16 has a light emitting element 22 and a light receiving element 24 attached to a substrate 20 on which an electrode pattern 18 is provided. The photo reflector 16 surrounds the light emitting element 22 and the light receiving element 24 and shields the light from the elements. The light shielding frame 26 is provided on the substrate 20 (see Patent Document 1). In the photo reflector 16, the light emitting element 22 and the light receiving element 24 are arranged so as to be closer to each other, light from the outside is shielded by the outer peripheral wall 26a of the light shielding frame 26, and between the elements by the intermediate wall 26b. It is configured to shield light.

  Usually, the substrate 20 in the photoreflector 16 is a substrate made of glass epoxy resin such as FR4 or BT resin widely used for this type of circuit board. When the substrate 20 made of such a material is used, the substrate 20 may transmit light to some extent and light may be transmitted through the substrate 20. As described above, when light is transmitted through the substrate 20 or transmitted through the substrate 20, the light receiving element 24 detects the light and causes a malfunction. In particular, in the case of an extremely small size photo reflector, the above problem appears more remarkably, and it is necessary to prevent slight light leakage.

In order to prevent such light leakage on the substrate, the present applicant provides a groove-like recess 3a between the light emitting element 2 and the light receiving element 4 on the surface of the substrate 3 as shown in FIG. The light-transmitting sealing members 6 and 8 that seal the light-emitting element 2 and the light-receiving element 4 in the 3a are partitioned, and a part of the light-shielding member 10 surrounded by the outer peripheral surface of the substrate 3 is formed. A photo reflector 1 having a fitted structure has been proposed (see Patent Document 2).
JP 2001-156325 A JP 2007-13050 A

  However, according to the photoreflector 1 having the structure shown in Patent Document 2, the concave portion 3a for fitting the lower end portion of the light shielding member 10 into the substrate 3 is provided as a light shielding measure between the light emitting element 2 and the light receiving element 4. Must be formed. For this reason, it is necessary to give the substrate 3 a certain thickness. However, if the thickness of the substrate 3 is increased, even if the light emitting element 2 and the light receiving element 4 are reduced in size and thickness, the reduction in the thickness of the entire photo reflector 1 is limited.

  Further, when the substrate 3 is formed of a material such as epoxy resin, the recess 3a for fitting the lower end portion of the light shielding member 10 can be formed relatively easily, but it is thin and flexible like a flexible substrate. When using a substrate having the above, the concave portion 3a cannot be formed. For this reason, in the photo reflector formed of the thin board | substrate, there exists a problem that an effective light leakage countermeasure cannot be performed.

  Accordingly, an object of the present invention is to provide a light shielding member capable of easily and reliably preventing light leakage from the light emitting element to the light receiving element on the substrate surface even when the substrate on which the light emitting element and the light receiving element are mounted is thin. And a method of manufacturing the same.

  In order to solve the above problems, a photo reflector of the present invention includes a substrate on which a light emitting side electrode pattern and a light receiving side electrode pattern are formed, a light emitting element disposed on the light emitting side electrode pattern and the light receiving side electrode pattern, and A light emitting element, a light emitting side sealing member and a light receiving side sealing member, and a light emitting side sealing member and a light receiving side seal; In a photoreflector provided with a light shielding frame that partitions the stop member, the light emitting side electrode pattern and the light receiving side electrode pattern are covered on the upper surface of the substrate, and the lower end of the light shielding frame is closely adhered to the photo reflector The light shielding layer is provided.

  The method of manufacturing a photoreflector according to the present invention includes a step of forming a light emitting side electrode pattern and a light receiving side electrode pattern on a substrate, and a light emitting element and a light receiving element are mounted on the light emitting side electrode pattern and the light receiving side electrode pattern, respectively. A step of forming a light shielding layer covering the light emitting side electrode pattern and the light receiving side electrode pattern on the substrate, and an integration of a translucent resin that seals the light emitting element and the light receiving element on the light shielding layer Forming a sealing body, and cutting between the light emitting element and the light receiving element of the sealing body over the upper surface of the light shielding layer to seal the light emitting element and the light receiving side sealing member A step of dividing the element into a light-receiving side sealing member that seals the element; and a partition between the light-emitting side sealing member and the light-receiving side sealing member on the light-shielding layer; Sealing member and light receiving Characterized by comprising a light shielding frame body which covers the outer peripheral side surface of the sealing member and a step of molding.

  According to the photo reflector of the present invention, the light shielding layer provided so as to cover the light emitting side electrode pattern and the light receiving side electrode pattern prevents light leakage from the light emitting element to the light receiving element on the substrate, and The outer peripheral side surfaces of the respective sealing members that seal the light emitting element and the light receiving element can be shielded from external light by the light shielding frame formed in close contact with the light shielding layer. As described above, since the surfaces other than the upper surface of the light emitting element and the light receiving element necessary for detecting the object to be detected are completely shielded from light, it is possible to provide a photo reflector having a detection accuracy free from the influence of noise due to light leakage or the like. It becomes possible.

  Further, according to the method of manufacturing a photoreflector according to the present invention, after the step of forming a light-shielding layer with a light-shielding resin on the substrate on which the light-emitting element and the light-receiving element are mounted, the light-emitting side sealing is performed on the light-shielding layer. A light shielding frame that covers the outer peripheral side surfaces of the body and the light receiving side sealing body is manufactured by the step of filling with the light shielding resin. As described above, the light shielding layer partially shields the light emitting element and the light receiving element, and further covers the outer peripheral side surfaces of the respective sealing members that seal the light emitting element and the light receiving element. There is no processing to dice a part. Further, since the light shielding layer and the light shielding frame are formed of the same light shielding resin, the adhesion is good and light leakage does not occur.

  Furthermore, since the light emitting side electrode pattern and the light receiving side electrode pattern on which the light emitting element and the light receiving element are mounted are completely covered on the substrate by the light shielding layer, the light emitting side electrode pattern and the light receiving side electrode due to secular change or the like An effect of preventing pattern corrosion and peeling can also be obtained.

  Embodiments of a photo reflector according to the present invention will be described below in detail with reference to the accompanying drawings. Here, FIG. 1 is a perspective view of a photo reflector of the present invention, FIG. 2 is a plan view of the photo reflector, and FIG. 3 is a cross-sectional view of the photo reflector. The photo reflector 30 in this embodiment includes a substrate 32, a light emitting element 42 and a light receiving element 44 mounted on the substrate 32, and a light emitting side sealing member 46 that seals the light emitting element 42 and the light receiving element 44. The light-receiving side sealing member 48, and the light-shielding member 60 including a light-shielding layer 61 and a light-shielding frame body 62 that shield light so that light does not leak from the surroundings of the sealing members 46 and 48.

  The substrate 32 is formed in a thin and flat quadrangular shape using glass epoxy resin such as FR4 or BT resin. A light-emitting side electrode pattern 34 and a light-receiving side electrode pattern 36 are formed on the surface of the substrate 32, and external connection terminals 38 having through holes shaped like a longitudinally cut cylindrical inner side surface on opposite side surfaces. Are provided in two places, and a back side electrode pattern 40 that is electrically connected to the light emitting side electrode pattern 34 and the light receiving side electrode pattern 36 via the external connection terminal 38 is formed on the back side. The light-emitting side electrode pattern 34 and the light-receiving side electrode pattern 36 in the present embodiment are configured by die-bonding electrode portions 34a and 36a and wire-bonding electrode portions 34b and 36b, respectively.

  The light emitting element 42 is made of, for example, a light emitting diode, and the light receiving element 44 is made of, for example, a photodiode. Each of them is die-bonded to the electrode portions 34a and 36a for die bonding, and is wire-bonded to the electrode portions 34b and 36b for wire bonding.

  Sealing members 46 and 48 made of a translucent resin are provided above the light emitting element 42 and the light receiving element 44, respectively. The sealing members 46 and 48 seal not only the light emitting element 42 and the light receiving element 44 but also all the wires connected thereto, the light emitting side electrode pattern 34 and the light receiving side electrode pattern 36.

  A characteristic feature of the present invention is that the light shielding member 60 is composed of a light shielding layer 61 formed by covering the upper surface of the substrate 32, and a light shielding frame 62 formed in close contact with the light shielding layer 61 without a gap. It is in the point. The light shielding layer 61 is formed on the entire upper surface of the substrate 32 so as to cover from the upper surface of the light emitting side electrode pattern 34 and the light receiving side electrode pattern 36 to the lower side of the outer peripheral surface of the light emitting element 42 and the light receiving element 44. Then, after light emitting side and light receiving side sealing members 46, 48 described later are formed on the light shielding layer 61, a light shielding frame 62 for shielding light by partitioning the sealing members 46, 48 is provided. It is formed.

  The light shielding layer 61 is provided to prevent light leakage on the substrate 32. The light shielding layer 61 is not particularly limited in form and material as long as it cuts visible light and infrared light. For example, a light-shielding resin paint having a thermosetting property mixed with a material such as carbon is fixed. Application may be performed so as to have a thickness, or the upper surface of the substrate 32 may be covered with a light shielding sheet.

  The light shielding frame 62 is formed so as to partition the sealing members 46 and 48 on the light shielding layer 61 and surround the outer peripheral surface of the sealing members 46 and 48 excluding the upper surface so as not to generate a gap. ing. The light shielding frame 62 has a mold disposed on the outer periphery of the substrate 32, and the mold is filled with the same light shielding resin as the light shielding layer 61 so that the upper surfaces of the sealing members 46 and 48 are exposed. And formed by heat curing.

  In the photoreflector 30 having the above configuration, the light shielding member 60 shields light between the light emitting element 42 and the light receiving element 44 and the periphery thereof, and can emit and receive light only in the planar direction (upper side in FIG. 1). In particular, since the lower end of the partition wall portion 50 of the light shielding frame 62 is in close contact with the upper surface of the light shielding layer 61, the light transmitted from the light emitting element 42 to the substrate 32 is shielded and reaches the light receiving element 44. It is effectively preventing.

  Further, since the light emitting side electrode pattern 34 and the light receiving side electrode pattern 36 are completely covered on the substrate 32 by the light shielding layer 61, the light emitting side electrode pattern 34 and An effect of preventing corrosion or peeling of the light receiving side electrode pattern 36 is also obtained.

  Next, a method for manufacturing the photo reflector 30 will be described with reference to FIGS. First, as shown in FIG. 4, the light emitting side electrode pattern 34, the light receiving side electrode pattern 36, the external connection terminal 38, and the back side electrode pattern 40 (see FIG. 3) is formed. Next, the light emitting element 42 and the light receiving element 44 are die-bonded on the electrode portions 34a and 36a, and are connected to the electrode portions 34b and 36b by wires.

  Next, as shown in FIG. 5, a light shielding layer 61 in which a light shielding resin is applied is formed on the upper surface of the substrate 32. The light shielding layer 61 is formed by covering the light emitting side electrode pattern 34 and the light receiving side electrode pattern 36 so as to cover a part of the outer peripheral surface of the light emitting element 42 and the light receiving element 44.

  After the light-shielding resin by the application is cured, as shown in FIG. 6, an integral sealing body 45 that seals the light-emitting element 42 and the light-receiving element 44 together with the light-transmitting resin is formed. The sealing body 45 is formed in a rectangular parallelepiped shape so as to cover the entire upper surface of the substrate 32. Thereafter, as shown in FIG. 7, the sealing body 45 is divided by dicing and the periphery is cut to form the sealing members 46 and 48. The dicing is preferably performed so that the upper surface of the light shielding layer 61 is slightly shaved so as not to reach the substrate 32.

  Finally, as shown in FIG. 8, the light shielding frame 62 is filled by filling light shielding resin between the sealing members 46 and 48 in the mold provided along the outer peripheral surface of the substrate 32. Form. The light shielding frame 62, the light shielding layer 61, and the sealing members 46 and 48 are made of a homogeneous resin such as an epoxy resin, and therefore have good adhesion. Therefore, the sealing members 46 and 48 can be formed in close contact with each other by the light shielding frame 62 and the light shielding layer 61, and light leakage from the light emitting element 42 to the light receiving element 44 can be prevented almost completely. it can.

  As described above, in the photo reflector of the present invention and the method of manufacturing the photo reflector, the gap is formed by the light shielding layer formed on the upper surface of the substrate and the light shielding frame formed on the light shielding layer. Therefore, light leakage from the light emitting element side to the light receiving element side on the substrate can be easily and effectively prevented. As a result, even if the photo reflector adopts a thin substrate that is difficult to process, it is possible to effectively suppress a decrease in detection sensitivity due to sufficient light leakage.

It is a perspective view of the photo reflector which concerns on this invention. It is a top view of the said photo reflector. It is sectional drawing of the said photo reflector. It is a perspective view which shows the process of forming an electrode pattern in a board | substrate and mounting a light emitting element and a light receiving element. It is a perspective view which shows the process of forming a light shielding layer on the said board | substrate. It is a perspective view which shows the process of forming an integrated sealing member on the said board | substrate. It is a perspective view which shows the process of dividing | segmenting the said integral sealing member into the light emission side and the light reception side sealing member. It is a perspective view which shows the process of filling light-shielding resin on the said light shielding layer, and forming a light-shielding frame. It is a perspective view which shows the structure of the conventional photo reflector. It is sectional drawing of the said conventional photo reflector. It is sectional drawing of the other conventional photo reflector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoreflector 2 Light emitting element 3 Substrate 3a Recessed part 4 Light receiving element 6 Sealing member 8 Sealing member 10 Light shielding member 16 Photoreflector 18 Electrode pattern 20 Substrate 22 Light emitting element 24 Light receiving element 26 Light shielding frame 26a Outer peripheral wall 26b Intermediate wall 30 Photo Reflector 32 Substrate 34 Light emitting side electrode pattern 34a, 34b Electrode part 36 Light receiving side electrode pattern 36a, 36b Electrode part 38 External connection terminal 40 Back side electrode pattern 42 Light emitting element 44 Light receiving element 45 Sealing body 46 Sealing member (light emitting side)
48 Sealing member (light receiving side)
50 Partition Wall 60 Light Shielding Member 61 Light Shielding Layer 62 Light Shielding Frame

Claims (5)

A substrate on which a light emitting side electrode pattern and a light receiving side electrode pattern are formed;
A light emitting element and a light receiving element respectively disposed on the light emitting side electrode pattern and the light receiving side electrode pattern;
A light emitting side sealing member and a light receiving side sealing member, each of which is sealed with a translucent resin above the light emitting element and the light receiving element, respectively;
In a photoreflector comprising a light shielding frame that partitions between the light emitting side sealing member and the light receiving side sealing member,
A photoreflector, wherein a light-shielding layer is provided on the upper surface of the substrate so as to cover each of the light-emitting side electrode pattern and the light-receiving side electrode pattern, and the lower end of the light-shielding frame is in close contact with the gap. The photoreflector according to claim 1, wherein the light shielding layer is formed on the substrate so as to expose an upper surface of the light emitting element and the light receiving element. The photoreflector according to claim 1, wherein the light shielding layer is formed of a thermosetting light shielding resin containing carbon. The photoreflector according to claim 1, wherein the light shielding layer is formed with a thickness at which the upper surfaces of the light emitting element and the light receiving element are exposed on upper surfaces of the light emitting side electrode pattern and the light receiving side electrode pattern. Forming a light emitting side electrode pattern and a light receiving side electrode pattern on a substrate;
Mounting a light emitting element and a light receiving element on the light emitting side electrode pattern and the light receiving side electrode pattern, respectively;
Forming a light shielding layer covering the light emitting side electrode pattern and the light receiving side electrode pattern on the substrate;
Forming an integral sealing body with a translucent resin that seals the light emitting element and the light receiving element on the light shielding layer;
A light emitting side sealing member that seals the light emitting element and a light receiving side sealing member that seals the light emitting element by cutting between the light emitting element and the light receiving element of the sealing body over the upper surface of the light shielding layer. Dividing the process into
A light shielding frame that partitions the light emitting side sealing member and the light receiving side sealing member on the light shielding layer and covers the outer peripheral side surfaces of the light emitting side sealing member and the light receiving side sealing member. A process for producing a photoreflector, comprising the step of:

Images