JP2017102417A - Lens with reflector and method for producing the same, and printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens with a reflector that can reduce mounting costs, prevents damage to a lens part, and can form a light emitter having excellent illuminance.SOLUTION: The present invention provides a lens with a reflector 1 that is used for a light emitter of a sensor and has a cylindrical reflector 2 predominantly composed of synthetic resin, and a lens part 3 housed in a hole of the reflector and predominantly composed of transparent synthetic resin, where the inner peripheral surface of the reflector has light reflective properties.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens with a reflector, a manufacturing method thereof, and a printed circuit board.

  A sensor using light may be mounted on the printed wiring board. Examples of the sensor include a photo interrupter and a photoreflective device. These sensors include a light emitting unit that emits irradiation light and a light receiving unit that detects the irradiation light, and the light receiving unit detects a change in the irradiation light that occurs when the object is present. Existence and position can be determined.

  Generally, the light emitting unit includes a light source such as a light emitting diode (LED) mounted on a printed wiring board, a lens unit that improves the directivity of light generated from the light source, and a lens holder that holds the lens unit. It consists of. The light emitting part is required to reduce the mounting cost, suppress the scratch on the lens part, and improve the illuminance.

  As a component constituting the light emitting unit, for example, a lens-holder complex including a synthetic resin lens unit and a synthetic resin lens holder has been proposed (see Japanese Patent Application Laid-Open No. 2014-112227). This lens-holder complex is bonded to the printed wiring board so as to surround the LED to form a light emitting portion. According to the above document, the lens-holder complex does not require a step of bonding the lens portion and the lens holder, and thus can reduce the mounting cost.

JP 2014-112227 A

  However, when the conventional lens-lens holder complex is used in the light-emitting portion, it cannot sufficiently meet the demands for suppressing damage to the lens portion and improving illuminance.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a reflector-equipped lens that can reduce the mounting cost, hardly damage the lens portion, and can form a light emitting portion with excellent illuminance.

  A lens with a reflector according to one aspect of the present invention made to solve the above problems is a lens with a reflector used in a light emitting part of a sensor, a cylindrical reflector mainly composed of a synthetic resin, and the reflector And a lens portion mainly composed of a transparent synthetic resin, and the inner peripheral surface of the reflector has light reflectivity.

  A printed circuit board according to another aspect of the present invention, which has been made to solve the above problems, includes a printed wiring board, a light emitting diode mounted on the printed wiring board, and the printed circuit board surrounding the light emitting diode. The above-mentioned lens with a reflector adhered to a wiring board is provided.

  A method for manufacturing a lens with a reflector according to still another aspect of the present invention made to solve the above-described problem is a method for manufacturing a lens with a reflector used in a light emitting part of a sensor, and a synthetic resin as a main component. A reflector injection molding step for injection molding a cylindrical reflector, and a lens portion injection molding step for injection-molding a lens portion mainly contained in a transparent synthetic resin, which is received in the hole of the reflector. The inner peripheral surface has light reflectivity, and the reflector injection molding step and the lens portion injection molding step are performed by a multicolor molding method.

  The lens with a lifter according to one embodiment of the present invention and the manufacturing method thereof can provide a lens with a lifter that can reduce the mounting cost, can hardly scratch the lens part, and can form a light emitting part with excellent illuminance. A printed circuit board according to another embodiment of the present invention includes a light-emitting portion that can reduce manufacturing costs, hardly damage the lens portion, and has excellent illuminance.

It is a typical top view showing a lens with a reflector of a 1st embodiment of the present invention. It is a typical end view in the A1-A1 line of FIG. It is a typical end view which shows the metal mold | die for reflectors used for manufacture of the lens with a reflector of FIG. It is a typical end view which shows the metal mold | die for lens parts used for manufacture of the lens with a reflector of FIG. It is a typical end view which shows 1 process of the manufacturing method of the lens with a reflector of FIG. FIG. 5 is a schematic end view showing the next step of FIG. 4 in the method for manufacturing the lens with a reflector of FIG. 1. FIG. 6 is a schematic end view showing a step subsequent to FIG. 5 in the method for manufacturing the lens with a reflector in FIG. 1. It is a typical end view showing a lens with a reflector of a 2nd embodiment of the present invention. It is a typical end view which shows the metal mold | die for reflectors used for manufacture of the lens with a reflector of FIG. It is a typical end view which shows the metal mold | die for lens parts used for manufacture of the lens with a reflector of FIG. It is a typical end view showing a lens with a reflector of a 3rd embodiment of the present invention. FIG. 10 is a schematic end view showing a reflector mold used for manufacturing the reflector-equipped lens of FIG. 9. FIG. 10 is a schematic end view showing a lens part mold used for manufacturing the reflector-equipped lens of FIG. 9. It is a typical end view showing a lens with a reflector of a 4th embodiment of the present invention. It is a typical end view which shows the metal mold | die for reflectors used for manufacture of the lens with a reflector of FIG. It is a typical end view which shows the metal mold | die for lens parts used for manufacture of the lens with a reflector of FIG. It is a typical end view showing the printed circuit board of a 5th embodiment of the present invention.

[Description of Embodiment of the Present Invention]
A lens with a reflector according to one aspect of the present invention is a lens with a reflector used for a light emitting part of a sensor, and is accommodated in a cylindrical reflector mainly composed of a synthetic resin and a hole of the reflector, and is a transparent composite. A lens portion mainly composed of a resin, and the inner peripheral surface of the reflector has light reflectivity.

  Since the reflector-equipped lens can be mounted at the same time when the light emitting portion is formed on the printed wiring board, the mounting cost can be reduced. Further, in the lens with a reflector, since the lens portion is housed in the hole of the cylindrical reflector, the lens portion is hardly damaged during and after mounting. Furthermore, since the inner peripheral surface of the reflector has light reflectivity, the reflector-equipped lens can suppress absorption and irregular reflection of light generated by a light source such as an LED, thereby reducing the illuminance of the light emitting portion to be formed. Can be improved. Here, the “main component” is a component having the largest content, for example, a component having a content of 50% by mass or more. “Transparent” is a concept including colored and transparent in addition to colorless and transparent. Specifically, it means that the total light transmittance measured in accordance with JIS-K7375: 2008 “Plastics—How to obtain total light transmittance and total light reflectance” is 70% or more.

  The transparent synthetic resin as the main component of the lens part may be crosslinked. Since the transparent synthetic resin as the main component of the lens part is crosslinked, the heat resistance of the lens part can be improved and reflow resistance can be imparted. As a result, the lens with a reflector can be mounted on the printed wiring board before the reflow process, so that the mounting cost can be further reduced.

  The synthetic resin as the main component of the reflector is preferably polyphthalamide. Polyphthalamide has excellent heat resistance and does not collapse when irradiated with ionizing radiation. Therefore, the heat resistance of the reflector can be improved by using polyphthalamide as the main component synthetic resin of the reflector, and the transparent synthetic resin as the main component of the lens part can be easily and reliably crosslinked by irradiation with ionizing radiation. it can. As a result, reflow resistance can be easily and reliably imparted to the lens with a reflector.

  The transparent synthetic resin as the main component of the lens part may be polyamide, cyclic polyolefin, or a combination thereof. The above-mentioned resin is excellent in the balance between transparency and high refractive index and high workability by injection molding or the like. Therefore, when the transparent synthetic resin as the main component of the lens part is the above-described synthetic resin, a lens part having a desired focal length and excellent in transparency can be easily and reliably formed. Moreover, since the above-mentioned resin can be cross-linked by irradiation with ionizing radiation, reflow resistance can be easily and reliably imparted to the lens portion.

  The total light reflectance of the inner peripheral surface of the reflector is preferably 80% or more. Thus, the illumination intensity of the light emission part formed can be improved more by making the said total light reflectance more than the said minimum. Here, “total light reflectance” refers to a value measured in accordance with JIS-K7375: 2008 “Plastics—How to obtain total light transmittance and total light reflectance”.

  The inner diameter of the reflector is preferably constant in the axial direction. As described above, since the inner diameter of the reflector is constant in the axial direction, an increase in the outer diameter can be easily suppressed even when a relatively large light source is used for forming the light emitting portion. Here, the “inner diameter of the reflector” means a diameter of a perfect circle having the same area as the inner area of the reflector in a cross section orthogonal to the axial direction. Further, “the inner diameter is constant in the axial direction” means that the difference between the maximum inner diameter and the minimum inner diameter is within 3% of the average inner diameter.

  The inner peripheral surface of the reflector is preferably tapered. Thus, the inner peripheral surface of the reflector is tapered, so that the mold release property of the mold and the reflector can be improved when the reflector is formed by injection molding. Further, by adhering the end of the reflector having the smaller inner diameter to the printed wiring board, the reflector serves as a concave mirror, and as a result, the illuminance and directivity of the light emitting unit can be further improved.

  A printed circuit board according to another aspect of the present invention includes a printed wiring board, a light emitting diode mounted on the printed wiring board, and the above-described reflector that is bonded to the printed wiring board so as to surround the light emitting diode. A lens.

  Since the printed circuit board uses the above-described lens with a reflector, the manufacturing cost can be reduced, the lens portion of the light emitting portion is hardly damaged, and the illuminance is excellent.

  A method for manufacturing a lens with a reflector according to still another aspect of the present invention made to solve the above-described problem is a method for manufacturing a lens with a reflector used in a light emitting part of a sensor, and a synthetic resin as a main component. A reflector injection molding step for injection molding a cylindrical reflector, and a lens portion injection molding step for injection molding a lens portion that is contained in a hole of the reflector and is mainly composed of a transparent synthetic resin. The inner peripheral surface has light reflectivity, and the reflector injection molding step and the lens portion injection molding step are performed by a multicolor molding method.

  The manufacturing method of the lens with a reflector can reduce a mounting cost by performing a reflector injection molding process and a lens part injection molding process by a multicolor molding method, and a light emitting part that is hard to be scratched and has excellent illuminance. A lens with a reflector that can be formed can be manufactured easily and reliably.

[Details of the embodiment of the present invention]
Hereinafter, a lens with a reflector according to an embodiment of the present invention and a manufacturing method thereof will be described in detail with reference to the drawings. In the present embodiment, in the axial direction of the lens with a reflector, the side that adheres to the printed wiring board may be referred to as a “light source side”, and the opposite side of the light source side may be referred to as an “outgoing side”.

[First Embodiment]
<Lens with reflector>
The reflector-equipped lens 1 shown in FIGS. 1 and 2 includes a rectangular tube-shaped reflector 2 and a transparent lens portion 3 accommodated in a hole of the reflector 2.

  The lens with reflector 1 is used in a light emitting unit of a sensor that detects the presence or absence of an object and its position using light. Specifically, the reflector-equipped lens 1 is bonded to the printed wiring board so as to surround a light source such as an LED mounted on the printed wiring board, thereby forming a light emitting portion together with the light source. Since the reflector-equipped lens 1 can simultaneously bond the reflector 2 and the lens unit 3 to the printed wiring board, the mounting cost can be reduced. Moreover, since the lens part 3 is accommodated in the hole of the reflector 2, the lens part 3 with a reflector is hard to be damaged at the time of mounting and after mounting.

[Reflector]
The reflector 2 has synthetic resin as a main component, and the inner peripheral surface has light reflectivity. Thus, since the inner peripheral surface of the reflector 2 has light reflectivity, absorption and irregular reflection of the light generated by the light source by the reflector 2 can be suppressed, and the illuminance of the formed light emitting portion can be improved. The color of the inner peripheral surface of the reflector 2 is a white color such as white, milky white, or grayish white from the viewpoint of improving light reflectivity.

  Although it does not specifically limit as an average outer diameter of the reflector 2, For example, they are 2 mm or more and 10 mm or less. Moreover, the average inner diameter of the reflector 2 is not particularly limited, but is, for example, 1 mm or more and 5 mm or less. Furthermore, although it does not specifically limit as average thickness of the reflector 2, For example, they are 0.5 mm or more and 3 mm or less. Furthermore, although it does not specifically limit as an axial direction average length of the reflector 2, For example, they are 1 mm or more and 5 mm or less. Here, the “outer diameter of the reflector” means a diameter of a perfect circle having the same area as the inner region of the outer periphery of the reflector 2 in a cross section orthogonal to the axial direction.

  The average inner diameter of the reflector 2 is constant in the axial direction. As described above, since the average inner diameter of the reflector 2 is constant in the axial direction, it is easy to suppress an increase in the outer diameter of the lens 1 with a reflector even when a relatively large light source is used for the light emitting portion.

  The synthetic resin as the main component of the reflector 2 is not particularly limited as long as it can be molded by injection molding or the like, and may be a crosslinked synthetic resin or a non-crosslinked synthetic resin. However, when the transparent synthetic resin as the main component of the lens portion 3 is cross-linked as described later, the synthetic resin as the main component of the reflector 2 is preferably one that has excellent heat resistance and does not collapse upon irradiation with ionizing radiation. . When the transparent synthetic resin as the main component of the lens unit 3 is cross-linked, the heat resistance of the reflector 2 can be improved by using such a synthetic resin as the main component of the reflector 2. Further, the transparent synthetic resin as the main component of the lens portion 3 can be easily and reliably crosslinked by irradiation with ionizing radiation. As a result, reflow resistance can be easily and reliably imparted to the lens 1 with a reflector. As such a synthetic resin, specifically, polyphthalamide which is a kind of polyamide is preferable.

  The lower limit of the total light reflectance on the inner peripheral surface of the reflector 2 is preferably 80%, more preferably 85%, and still more preferably 90%. On the other hand, although it does not specifically limit as an upper limit of the total light reflectance of the internal peripheral surface of the reflector 2, For example, it is 95%. When the total light reflectance of the inner peripheral surface of the reflector 2 is smaller than the lower limit, the illuminance of the light emitting part to be formed may not be sufficiently improved.

  The reflector 2 usually contains a white pigment in order to improve light reflectivity. Examples of the white pigment include titanium dioxide, potassium titanate, zirconium dioxide, zinc sulfide, zinc oxide, magnesium oxide, alumina, aluminum hydroxide, and glass fiber. As a minimum of content of a white pigment in reflector 2, 5 mass% is preferred and 10 mass% is more preferred. On the other hand, as an upper limit of content of the white pigment in the reflector 2, 40 mass% is preferable and 30 mass% is more preferable. When the content of the white pigment in the reflector 2 is smaller than the above lower limit, the light reflectivity of the inner peripheral surface becomes insufficient, and the illuminance of the formed light emitting part may not be sufficiently improved. Conversely, when the content of the white pigment in the reflector 2 exceeds the above upper limit, the strength of the reflector 2 may be reduced.

  The reflector 2 may contain an additive in addition to the synthetic resin and the white pigment. Examples of the additive include an antioxidant, an ultraviolet absorber, a visible light absorber, a weather resistance stabilizer, a copper damage inhibitor, a flame retardant, a lubricant, a conductive agent, a plating agent, and a filler. Examples of the filler include inorganic whisker such as basic magnesium sulfate whisker, zinc oxide whisker and potassium titanate whisker, inorganic filler such as montmorillonite, synthetic smectite and carbon fiber, cellulose, kenaf, aramid fiber, organic clay, etc. Can be mentioned. Thus, the desired characteristic of the reflector 2 can be improved because the reflector 2 contains the additive. Although it does not specifically limit as an upper limit of content of the said additive in the reflector 2, For example, it is 30 mass%.

[Lens part]
The lens unit 3 has a transparent synthetic resin as a main component. The lens unit 3 is a substantially plate-like member having a first surface on the emission side and a second surface on the light source side. The first surface is planar. A part of the surface of the second surface bulges around the central portion to form a convex portion 3a. The lens unit 3 is accommodated in the vicinity of the exit side end in the hole of the reflector 2, and the first surface constitutes the flat bottom surface of the lens 1 with a reflector together with the exit side end surface of the reflector 2. That is, the first surface and the exit side end surface of the reflector 2 are flush with each other. As described above, by forming the flat bottom surface of the lens 1 with reflector by the reflector 2 and the lens unit 3, unevenness on the bottom surface of the lens 1 with reflector can be reduced, and as a result, adhesion of dust and the like can be suppressed. . In the lens 1 with a reflector, since the convex portion 3a of the lens portion 3 functions as a convex lens, the directivity of light generated from the light source of the light emitting portion to be formed can be improved by the convex portion 3a. Moreover, since the lens part 3 is accommodated in the hole of the lifter 2, it is hard to be damaged at the time of mounting and after mounting.

  Furthermore, the lens 1 with a reflector has the following advantages compared with the lens 11 with a reflector according to a second embodiment to be described later, that is, with the light source side and the emission side of the lens unit 3 reversed. That is, in the lens with reflector 1, the convex portion 3a is not easily damaged because the convex portion 3a is not exposed when the light emitting portion is formed. In addition, the lens with reflector 1 does not need to increase the average length in the axial direction of the reflector 2 in order to position the apex of the convex portion 3a closer to the light source side than the virtual surface including the emission side end face of the reflector 2. , It is easy to reduce the axial average length (average height).

  The maximum thickness of the lens portion 3, that is, the minimum distance between the apex of the convex portion 3a and the first surface is, for example, not less than 0.4 mm and not more than 2 mm. Moreover, the average thickness of the region other than the convex portion 3a of the lens portion 3 is, for example, 0.2 mm or more and 1 mm or less. Furthermore, the diameter when the convex portion 3a is viewed in plan is, for example, not less than 0.5 mm and not more than 3 mm. Furthermore, the radius of curvature of the convex portion 3a is, for example, not less than 0.4 mm and not more than 2 mm.

  The transparent synthetic resin as the main component of the lens unit 3 is preferably crosslinked. Thus, the transparent synthetic resin of the main component of the lens part 3 is cross-linked, whereby the heat resistance of the lens part 3 can be improved and reflow resistance can be imparted. As a result, the reflector-equipped lens 1 can be mounted before the reflow process, so that the mounting cost can be further reduced.

  When the transparent synthetic resin as the main component of the lens part 3 is crosslinked, the storage elastic modulus at a high temperature (for example, 270 ° C.) of the lens part 3 increases as the degree of crosslinking increases. Therefore, the storage elastic modulus at high temperature of the lens unit 3 is an index of the degree of crosslinking of the transparent synthetic resin. When the transparent synthetic resin as the main component of the lens part 3 is crosslinked, the lower limit of the storage elastic modulus at 270 ° C. of the lens part 3 is preferably 0.1 MPa, and more preferably 1 MPa. On the other hand, the upper limit of the storage elastic modulus at 270 ° C. of the lens unit 3 is not particularly limited, but is, for example, 50 MPa. When the storage elastic modulus at 270 ° C. of the lens unit 3 is smaller than the lower limit, the reflow resistance of the lens unit 3 may not be sufficiently improved. Here, the “storage modulus” is a term (real term) constituting a complex modulus representing the relationship between stress and strain when sinusoidal vibration strain is applied to a viscoelastic body. The value measured by (DMS). More specifically, it refers to a value measured at room temperature (25 ° C.) to 10 ° C./min using “DVA-200” manufactured by IT Measurement Control Co., Ltd. as a viscoelasticity measuring device.

  The lower limit of the refractive index of the lens unit 3 is preferably 1.4, and more preferably 1.45. On the other hand, the upper limit of the refractive index of the lens unit 3 is not particularly limited, but is 1.8, for example. When the refractive index of the lens unit 3 is smaller than the lower limit, the directivity of light emitted from the light emitting unit may not be sufficiently improved. Here, the “refractive index” refers to a value measured in accordance with JIS-K7142: 2008 “Plastic—How to obtain a refractive index”.

  The lens unit 3 may be colored and transparent. Thus, the wavelength of the light irradiated from the light emitting part can be adjusted by making the lens part 3 colored and transparent so that only a specific wavelength can be transmitted.

  As the transparent synthetic resin as the main component of the lens unit 3, polyamide, cyclic polyolefin, and a combination thereof are preferable. The above-mentioned resin is excellent in the balance between transparency and high refractive index and high workability by injection molding or the like. Therefore, since the transparent synthetic resin as the main component of the lens unit 3 is the above-described synthetic resin, the lens unit 3 having a desired focal length and excellent in transparency can be easily and reliably formed. Moreover, since the above-mentioned resin can be cross-linked by irradiation with ionizing radiation, it can easily and reliably impart reflow resistance to the lens unit 3.

  Polyamide is a synthetic resin having an amide bond in the repeating unit of the main chain, and is obtained by condensing an amine component such as diamine and an acid component such as dicarboxylic acid. The polyamide is preferably amorphous and has a high glass transition point. Such polyamides have ring structures such as aromatic rings and alicyclic rings as disclosed in, for example, JP-A Nos. 62-121726, 63-170418, and 2004-256812. It can obtain by using the monomer which has. The polyamide may be a copolyamide using two or more types of amine components or two or more types of acid components.

Specific examples of the polyamide include, for example, a polyamide comprising terephthalic acid and an isomer mixture of 2,2,4-trimethylhexamethylenediamine and 2,4,4-trimethylhexamethylenediamine,
A polyamide comprising isophthalic acid and 1,6-hexamethylenediamine,
A polyamide comprising terephthalic acid and / or isophthalic acid and 1,6-hexamethylenediamine,
A polyamide comprising isophthalic acid, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, and lauric lactam or caprolactam;
A polyamide comprising 1,12-dodecanedioic acid or 1,10-dodecanedioic acid, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, and lauric lactam or caprolactam as optional monomer components;
A polyamide comprising isophthalic acid, 4,4′-diaminodicyclohexylmethane, and lauric lactam or caprolactam;
A polyamide comprising 1,12-dodecanedioic acid and 4,4′-diaminodicyclohexylmethane,
And a copolyamide composed of a mixture of terephthalic acid and isophthalic acid, 3,3′-dimethyl-4,4′-diamidicyclohexylmethane, and lauric lactam.

  The polyamide may be a mixture of two or more polyamides. In this case, crystalline polyamide may be included as long as it is transparent after mixing. Specific examples of trade names for the polyamide include Grillamide TR-55 and TR-90 (manufactured by Ms Chemie Japan).

  Cyclic polyolefin is a kind of polyolefin and is obtained by polymerizing a monomer containing a cyclic olefin monomer. Examples of the cyclic olefin monomer include those described in JP-A-8-20692, and cyclopentene, 2-norbornene, and tetracyclododecene compounds are preferable.

  The lens unit 3 may contain an additive in addition to the transparent synthetic resin. As said additive, the thing etc. which do not reduce transparency and a refractive index among the additives illustrated with the reflector 2, for example are mentioned. Moreover, when making the lens part 3 colored and transparent, the lens part 3 may contain a pigment as said additive. Thus, the desired characteristic of the lens part 3 can be improved because the lens part 3 contains the said additive. Although it does not specifically limit as an upper limit of content of the said additive in the lens part 3, For example, it is 25 mass%.

<Manufacturing method of lens with reflector>
The manufacturing method of the lens with a reflector includes a reflector injection molding step of injection molding a cylindrical reflector mainly composed of a synthetic resin, and a lens portion that is accommodated in the hole of the reflector and mainly composed of a transparent synthetic resin. A lens part injection molding process for injection molding, and the reflector injection molding process and the lens part injection molding process are performed by a multicolor molding method. Thus, the manufacturing method of the said lens with a reflector can manufacture the said lens with a reflector easily and reliably by performing the said reflector injection molding process and the said lens part injection molding process by a multicolor molding method.

  The manufacturing method of the lens with a reflector may further include an ionizing radiation irradiation step of irradiating the lens portion with ionizing radiation after the lens portion injection molding step. Thus, the transparent synthetic resin which is a main component of the said lens part can be bridge | crosslinked because the manufacturing method of the said lens with a reflector is equipped with the said ionizing radiation irradiation process. As a result, the heat resistance of the lens portion can be improved, and reflow resistance can be imparted to the lens with a reflector.

[Reflector injection molding process]
In this step, a cylindrical reflector mainly composed of synthetic resin is injection molded. FIG. 3A shows a reflector mold Y1 used in this step. The reflector mold Y1 includes a primary mold X1 as an upper mold and a common mold X2 as a lower mold, and a cylindrical cavity C1 is formed between the primary mold X1 and the common mold X2. Yes. By injecting the resin composition for reflector molding into the cylindrical cavity C1 of the reflector mold Y1, and cooling and solidifying it, a cylindrical reflector Z1 can be formed as shown in FIG.

  The reflector molding resin composition contains the above-described synthetic resin as a main component in the reflector and contains an additive as necessary.

  The injection molding temperature of the reflector can be appropriately changed depending on the melting point of the synthetic resin used, and is, for example, 200 ° C. or higher and 330 ° C. or lower.

[Lens part injection molding process]
In this step, a lens portion mainly composed of a transparent synthetic resin is injection molded. FIG. 3B shows the lens part mold Y2 used in this step. The lens part mold Y2 includes a secondary mold X3 as an upper mold and a common mold X2 as a lower mold. In the lens part mold Y2, the lens-shaped cavity C2 with a reflector is formed between the common mold X2 and the secondary mold X3.

  In this step, after the reflector injection molding step, the primary mold X1 and the reflector Z1 are released, and the reflector Z1 and the common mold X2 are kept in close contact with each other in the reflector Z1 and the common mold X2. Fit type X2. As a result, as shown in FIG. 5, a cylindrical reflector Z1 molded in the reflector injection molding process is partially filled between the common mold X2 and the secondary mold X3. Further, a lens-shaped cavity C3 is formed in a portion where the reflector Z1 between the common mold X2 and the secondary mold X3 is not filled. The lens portion Z2 can be formed as shown in FIG. 6 by injecting the lens portion-forming resin composition into the lens portion-shaped cavity C3 of the lens portion mold Y2 and cooling and solidifying the resin composition. Simultaneously with the formation of the lens portion Z2, the reflector Z1 and the lens portion Z2 are integrated by heat fusion, and the lens Z3 with reflector is obtained.

  The lens part molding resin composition contains the transparent synthetic resin described above in the lens part as a main component, and optionally contains an additive. Moreover, when the transparent synthetic resin which is a main component of a lens part is bridge | crosslinked by the ionizing radiation irradiation process mentioned later, the said resin composition for lens part shaping | molding may contain a crosslinking adjuvant.

Examples of the crosslinking aid include oximes such as p-quinonedioxime and p, p′-dibenzoylquinonedioxime;
Acrylates or methacrylates such as ethylene dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, cyclohexyl methacrylate, mixtures of acrylic acid and zinc oxide, allyl methacrylate;
Vinyl monomers such as divinylbenzene, vinyltoluene and vinylpyridine;
Allyl compounds such as hexamethylene diallyl nadiimide, diallyl itaconate, diallyl phthalate, diallyl isophthalate, diallyl monoglycidyl isocyanurate, triallyl cyanurate, triallyl isocyanurate (TAIC);
And maleimide compounds such as N, N′-m-phenylenebismaleimide and N, N ′-(4,4′-methylenediphenylene) dimaleimide.

  When the main component of the lens part molding resin composition is polyamide, TAIC is preferable as the crosslinking aid from the viewpoint of further improving heat resistance.

  When the said lens part shaping | molding resin composition contains the said crosslinking adjuvant, as a minimum of content of the said crosslinking adjuvant, 0.1 mass% is preferable and 0.5 mass% is more preferable. On the other hand, as an upper limit of content of the said crosslinking adjuvant, 25 mass% is preferable and 15 mass% is more preferable. When the content of the crosslinking aid is smaller than the lower limit, the transparent synthetic resin that is the main component of the lens part may be insufficiently crosslinked. Conversely, if the content of the crosslinking aid exceeds the upper limit, the moldability of the lens part molding resin composition may be reduced.

  As a commercial product of the lens part molding resin composition, “Teralink (registered trademark)” manufactured by Sumitomo Electric Fine Polymer Co., Ltd. can be suitably used. This Terralink is a crosslinkable thermoplastic resin composition mainly composed of polyamide, cyclic polyolefin, or a combination thereof.

  The injection molding temperature of the lens part can be appropriately changed depending on the melting point of the synthetic resin to be used.

[Ionizing radiation irradiation process]
In this step, after the lens portion injection molding step, the lens portion is irradiated with ionizing radiation to crosslink the transparent synthetic resin that is the main component of the lens portion. By this step, the heat resistance of the lens portion can be improved and reflow resistance can be imparted.

  Examples of the ionizing radiation include γ-rays, electron beams, X-rays, neutron beams, high-energy ion beams, and the like, and electron beams are preferable. Moreover, as a minimum of the irradiation dose of ionizing radiation, 100 kGy is preferable and 300 kGy is more preferable. On the other hand, the upper limit of the irradiation dose is preferably 1,000 kGy, more preferably 700 kGy. When the said irradiation dose is smaller than the said minimum, there exists a possibility that the crosslinking reaction of the said transparent synthetic resin may not fully advance. On the contrary, when the said irradiation dose exceeds the said upper limit, there exists a possibility that the said transparent synthetic resin may decompose | disassemble. Therefore, by setting the irradiation dose within the above range, crosslinking can be sufficiently advanced while suppressing the decomposition of the transparent synthetic resin.

[Second Embodiment]
<Lens with reflector>
The lens 11 with a reflector in FIG. 7 includes a rectangular cylindrical reflector 12 and a transparent lens portion 13 accommodated in a hole of the reflector 12. The lens 11 with reflector, the reflector 12 and the lens unit 13 can be the same as the lens 1 with reflector, the reflector 2 and the lens unit 3 of the first embodiment except for the position of the lens unit 13.

[Lens part]
The lens unit 13 is a substantially plate-like member having a first surface on the light source side and a second surface on the emission side. The first surface is planar. A part of the surface of the second surface bulges around the central portion to form a convex portion 13a. That is, the lens unit 13 corresponds to a lens unit 3 according to the first embodiment in which the light source side and the emission side are reversed. The lens unit 13 is accommodated in the vicinity of the exit side end in the hole of the reflector 12. Since the lens part 13 is accommodated in the hole of the lifter 12, it is difficult to be damaged during and after mounting. The vertex of the convex portion 13 a is located on the light source side from the virtual surface including the emission-side end surface of the reflector 12. The minimum distance between the apex of the convex portion 13a and the virtual surface can be set to 0.05 mm to 1 mm, for example. In this way, the convex portion 13a can be made less likely to be damaged by disposing the lens portion 13 so that the vertex of the convex portion 13a is located on the light source side from the virtual surface.

  The lens 11 with a reflector can increase the distance from a light source such as an LED to the convex portion 13a as compared with the lens 1 with a reflector of the first embodiment. For this reason, the lens with reflector 11 uses a material having a relatively low refractive index for the lens unit 13 and can easily improve the directivity of light emitted from the light emitting unit even when the focal length is increased.

<Manufacturing method of lens with reflector>
The manufacturing method of the lens with a reflector includes a reflector injection molding step of injection molding a cylindrical reflector mainly composed of a synthetic resin, and a lens portion that is accommodated in the hole of the reflector and mainly composed of a transparent synthetic resin. A lens part injection molding process for molding, and the reflector injection molding process and the lens part injection molding process are performed by a multicolor molding method. The manufacturing method of the lens with a reflector may further include an ionizing radiation irradiation step of irradiating the lens portion with ionizing radiation. The manufacturing method of the lens with a reflector can be the same as the manufacturing method of the lens with a reflector of the first embodiment except for a mold used in the reflector injection molding step and the lens part injection molding step.

[Reflector injection molding process]
FIG. 8A shows a reflector mold Y11 used in this step. The reflector mold Y11 includes a primary mold X11 as an upper mold and a common mold X12 as a lower mold, and a cylindrical cavity C11 is formed between the primary mold X11 and the common mold X12. Yes.

[Lens part injection molding process]
FIG. 8B shows the lens part mold Y12 used in this step. The lens part mold Y12 includes a secondary mold X13 as an upper mold and a common mold X12 as a lower mold. In the lens part mold Y12, the lens-shaped cavity C12 with a reflector is formed between the common mold X12 and the secondary mold X13.

[Third Embodiment]
<Lens with reflector>
The lens 21 with a reflector in FIG. 9 includes a rectangular cylindrical reflector 22 and a transparent lens portion 23 accommodated in the hole of the reflector 22. The lens 21 with reflector, the reflector 22 and the lens unit 23 can be the same as the lens 1 with reflector, the reflector 2 and the lens unit 3 of the first embodiment except for the shape.

[Reflector]
The inner peripheral surface of the reflector 22 is tapered. That is, the inner diameter of the reflector 22 gradually increases from the light source side to the emission side. Thus, when the reflector 22 is formed by injection molding, the mold and the releasability of the reflector 22 can be improved because the inner peripheral surface of the reflector 22 is tapered. In addition, by adhering the light source side end of the lens with reflector 21 to the printed wiring board, the reflector 22 serves as a concave mirror, and as a result, the illuminance and directivity of the light emitting unit can be further improved.

  The inner diameter of the reflector 22 on the emission side is, for example, 2 mm or more and 8 mm or less. Further, the inner diameter of the reflector 22 on the light source side is, for example, not less than 0.5 mm and not more than 5 mm. Furthermore, although it does not specifically limit as an axial direction average length of the reflector 2, For example, they are 1 mm or more and 5 mm or less. Furthermore, the average thickness on the exit side of the reflector 22 is, for example, not less than 0.2 mm and not more than 1 mm. Furthermore, the average thickness on the light source side of the reflector 22 is, for example, not less than 0.5 mm and not more than 2.5 mm. Further, the taper ratio of the reflector 22 is, for example, 0.3 or more and 1 or less. Here, the “taper ratio of the reflector” refers to a value obtained by (the inner diameter of the reflector on the emission side−the inner diameter on the light source side of the reflector) / the average length in the axial direction of the reflector.

[Lens part]
The lens portion 23 is a substantially square frustum-shaped member having an upper surface on the light source side and a bottom surface on the emission side. In the lens portion 23, a part of the upper surface is recessed into a columnar shape such as a columnar shape or a quadrangular columnar shape to form a light source accommodating space 23b, and a part of the bottom surface is raised around the central portion to project the convex portion 23a. Is forming. The convex portion 23 a is located on the light source side with respect to the virtual surface including the emission-side end surface of the reflector 22. The distance between the vertex of the convex portion 23a and the virtual surface can be set to, for example, 0.05 mm or more and 1 mm or less. In this way, the convex portion 23a can be made harder to be damaged by arranging the lens portion 23 so that the vertex of the convex portion 23a is located on the light source side from the virtual surface.

<Manufacturing method of lens with reflector>
The manufacturing method of the lens with a reflector includes a reflector injection molding step of injection molding a cylindrical reflector mainly composed of a synthetic resin, and a lens portion that is accommodated in the hole of the reflector and mainly composed of a transparent synthetic resin. A lens part injection molding process for molding, and the reflector injection molding process and the lens part injection molding process are performed by a multicolor molding method. The manufacturing method of the lens with a reflector may further include an ionizing radiation irradiation step of irradiating the lens portion with ionizing radiation. The manufacturing method of the lens with a reflector can be the same as the manufacturing method of the lens with a reflector of the first embodiment except for a mold used in the reflector injection molding step and the lens part injection molding step.

[Reflector injection molding process]
FIG. 10A shows a reflector mold Y21 used in this step. The reflector mold Y21 includes a primary mold X21 as an upper mold and a common mold X22 as a lower mold, and a cylindrical cavity C21 is formed between the primary mold X21 and the common mold X22. Yes.

[Lens part injection molding process]
FIG. 10B shows a lens part mold Y22 used in this step. The lens part mold Y22 includes a secondary mold X23 as an upper mold and a common mold X22 as a lower mold. In the lens part mold Y22, the lens-shaped cavity C22 with a reflector is formed between the common mold X22 and the secondary mold X23.

[Fourth Embodiment]
<Lens with reflector>
The reflector-equipped lens 31 shown in FIG. 11 includes a rectangular tubular reflector 32 and a transparent lens portion 33 accommodated in a hole of the reflector 32. The lens 31 with reflector, the reflector 32 and the lens unit 33 can be the same as the lens 21 with reflector, the reflector 22 and the lens unit 23 of the third embodiment except for the shape of the lens unit 33.

[Lens part]
The lens portion 33 is a substantially square frustum-shaped member having an upper surface on the light source side and a bottom surface on the emission side. In the lens portion 33, a part of the upper surface is depressed in a substantially cylindrical shape to form a light source accommodating space 33b. In addition, a part of the bottom surface on the emission side of the light source accommodation space 33b is raised to the light source side around the center portion to form a convex portion 33a. The bottom surface of the lens unit 33 has a flat plate shape, and forms the flat bottom surface of the lens 31 with a reflector together with one end surface of the reflector 32. That is, the bottom surface and the emission side end surface of the reflector 32 are flush with each other. Thus, by forming the flat bottom surface of the lens 31 with reflector by the reflector 32 and the lens portion 33, the unevenness of the bottom surface of the lens 31 with reflector can be reduced, and as a result, adhesion of dust and the like can be suppressed. .

<Manufacturing method of lens with reflector>
The manufacturing method of the lens with a reflector includes a reflector injection molding step of injection molding a cylindrical reflector mainly composed of a synthetic resin, and a lens portion that is accommodated in the hole of the reflector and mainly composed of a transparent synthetic resin. A lens part injection molding process for molding, and the reflector injection molding process and the lens part injection molding process are performed by a multicolor molding method. The manufacturing method of the lens with a reflector may further include an ionizing radiation irradiation step of irradiating the lens portion with ionizing radiation. The manufacturing method of the lens with a reflector can be the same as the manufacturing method of the lens with a reflector of the first embodiment except for a mold used in the reflector injection molding step and the lens part injection molding step.

[Reflector injection molding process]
FIG. 12A shows a reflector mold Y31 used in this step. The reflector mold Y31 includes a primary mold X31 as an upper mold and a common mold X32 as a lower mold, and a cylindrical cavity C31 is formed between the primary mold X31 and the common mold X32. Yes.

[Lens part injection molding process]
FIG. 12B shows a lens part mold Y32 used in this step. The lens part mold Y32 includes a secondary mold X33 as an upper mold and a common mold X32 as a lower mold. In the lens part mold Y32, a lens-shaped cavity C32 with a reflector is formed between the common mold X32 and the secondary mold X33.

[Fifth Embodiment]
<Printed circuit board>
The printed circuit board 4 in FIG. 13 includes a printed wiring board 5, an LED 6 mounted on the printed wiring board 5, and the lens 1 with a reflector bonded to the printed wiring board 5 so as to surround the LED 6.

  The printed wiring board 5 mainly includes an insulating substrate and a conductive pattern laminated on at least one surface of the substrate. The printed wiring board 5 may further include a coverlay that is laminated on the surface of the conductive pattern opposite to the substrate. The said conductive pattern has a land part for mounting LED. Here, the “land portion” refers to a portion in which the wiring is expanded to a size that allows solder connection in order to perform solder connection when mounting a chip component in the middle of the wiring circuit in the conductive pattern.

  As the LED 6, a multi-color light emitting type or a single color light emitting type, and a surface mount type light emitting diode packaged with a chip type or a synthetic resin can be used. The LED 6 is mounted on the land portion of the conductive pattern.

<Method for manufacturing printed circuit board>
The printed circuit board includes, for example, an LED disposing step for disposing an LED on a printed wiring board, a lens adhering step for adhering the lens with a reflector to the printed wiring board so as to surround the LED, and the lens with a reflector. It can manufacture by the method provided with the reflow process process which performs a reflow process before an adhesion process or after a lens adhesion process with a reflector. When the transparent synthetic resin that is the main component of the lens portion of the lens with the reflector is cross-linked, the reflow treatment step may be performed after the lens attachment step with the reflector from the viewpoint of omitting the manual mounting work after the reflow. preferable.

[LED placement process]
In this step, the LED is disposed on the land portion of the printed wiring board. The method for disposing the LED on the printed wiring board is not particularly limited, and a conventionally known method can be used.

[Lens bonding process with reflector]
In this step, the lens with the reflector is bonded to the printed wiring board so as to surround the LED. The method for adhering the lens with a reflector is not particularly limited. For example, an adhesive having a thermosetting resin as a main component can be used. In this case, in order to harden the said adhesive agent, it is good to heat at 120 degreeC or more and 180 degrees C or less after adhesion | attachment.

[Reflow process]
In this step, reflow processing is performed to solder the LEDs. The reflow temperature is, for example, 200 ° C. or more and 300 ° C. or less. Moreover, as reflow time, it is 1 minute or more and 5 minutes or less, for example.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  The shape of the reflector is not limited to a quadrangular cylindrical shape as long as it is cylindrical, and may be another shape such as a cylindrical shape or a triangular cylindrical shape.

  The reflector may have a multilayer structure including, for example, an outer layer and an inner layer laminated inside the outer layer. In this case, only the inner peripheral surface of the inner layer is required to have light reflectivity, and the outer layer is preferably formed of a material having no light reflectivity such as black. Thus, by forming the outer layer with a material that does not have light reflectivity, it is possible to suppress light outside the light emitting unit from being transmitted through the reflector and emitted from the inside of the light emitting unit.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<Manufacture of lens with reflector>
Lens part molding resin compositions A1 to A3 and reflector molding resin compositions B1 to B2 used in this example are shown below.

A1: “Teralink” by Sumitomo Electric Fine Polymer
A2: “CALIBRE 301-22” from Sumika Stylon Polycarbonate
A3: “Acrypet TF9” by Mitsubishi Rayon

  In addition, A1 is a crosslinkable resin composition which has polyamide as a main component and crosslinks by electron beam irradiation. A2 is a non-crosslinkable resin composition containing polycarbonate as a main component and not crosslinked by electron beam irradiation. A3 is a non-crosslinkable resin composition containing methacrylic resin as a main component and not crosslinked by electron beam irradiation.

B1: Polyphthalamide (9T nylon) ("Amodel 4422" from Solvay)
B2: Polyphthalamide (9T nylon) (Kuraray "Genesta TA112")

[Production Example 1]
A lens with a reflector was manufactured by using the resin composition A1 for molding a lens part and the resin composition B1 for reflector molding. The injection molding conditions were that the reflector was molded at 310 ° C. and the lens part was molded at 250 ° C. The shape of the lens with a reflector was the same as that of the first embodiment shown in FIGS. The size of the lens with the reflector is as follows: the average outer diameter of the reflector is 6 mm, the average inner diameter of the reflector is 3 mm, the maximum thickness of the lens part is 1 mm, the average thickness of the region other than the convex part of the lens part is 0.5 mm, and the convex part is The diameter in plan view was 2 mm, and the maximum thickness of the convex portion was 0.5 mm. The above-mentioned lens with a reflector was subjected to an electron beam irradiation process of 500 kGy to crosslink the terralink forming the lens part.

[Production Examples 2 to 8]
The reflector-equipped lenses of Production Examples 2, 5, and 6 were produced in the same manner as in Production Example 1 except that the molding materials shown in Table 1 were used as the molding materials for the lens part and the reflector. In addition, the lenses shown in Table 1 were used as molding materials for the lens portion and the reflector, and the same operation as in Production Example 1 was performed except that the electron beam irradiation was not performed. The lenses with reflectors in Production Examples 3, 4, 7 and 8 were manufactured. Manufactured.

<Evaluation>
By the following method, the presence or absence of the lens melting at the time of reflow of the lens with a reflector of manufacture examples 1-8, and the illumination intensity at the time of using for a light emission part were measured. The structures and measurement results of Production Examples 1 to 8 are shown in Table 1.

[Presence or absence of lens melting during reflow]
The lens with a reflector was heat-treated at 260 ° C. for 3 minutes corresponding to the reflow treatment. The appearance of the lens with the reflector after the heat treatment was visually observed, and the presence or absence of melting of the lens portion was evaluated.

  As is clear from Table 1, the lenses with reflectors of Production Examples 1 and 2 can impart reflow resistance by using a crosslinkable resin composition as the lens portion molding resin composition and performing electron beam irradiation processing. It was.

  The lens with a lifter according to one embodiment of the present invention and the manufacturing method thereof can provide a lens with a lifter that can reduce the mounting cost, hardly damage the lens unit, and can improve the illuminance of the light emitting unit. The printed circuit board which concerns on another one aspect | mode of this invention is equipped with the light emission part which is hard to be damaged to a lens part and is excellent in illumination intensity, reducing manufacturing cost.

1, 11, 21, 31 Lenses with reflectors 2, 12, 22, 32 Reflectors 3, 13, 23, 33 Lens portions 3a, 13a, 23a, 33a Convex portions 23b, 33b Light source accommodation space 4 Printed circuit board 5 Print Wiring board 6 LED
X1, X11, X21, X31 Common mold X2, X12, X22, X32 Primary mold X3, X13, X23, X33 Secondary mold Y1, Y11, Y21, Y31 Reflector mold Y2, Y12, Y22, Y32 Lens Die for part Z1 Reflector Z2 Lens part Z3 Lens with reflector C1, C11, C21, C31 Cylindrical cavity C2, C12, C22, C32 Lens-like cavity with reflector C3 Lens-like cavity

Claims (9)

A lens with a reflector used for the light emitting part of the sensor,
A cylindrical reflector composed mainly of synthetic resin;
A lens portion housed in a hole of the reflector and having a transparent synthetic resin as a main component,
A lens with a reflector, wherein the inner peripheral surface of the reflector has light reflectivity.   The lens with a reflector according to claim 1, wherein the transparent synthetic resin as a main component of the lens portion is crosslinked.   The lens with a reflector according to claim 2, wherein the synthetic resin as a main component of the reflector is polyphthalamide.   The lens with a reflector according to claim 1, wherein the transparent synthetic resin as a main component of the lens portion is polyamide, cyclic polyolefin, or a combination thereof.   The lens with a reflector according to any one of claims 1 to 4, wherein a total light reflectance of an inner peripheral surface of the reflector is 80% or more.   The lens with a reflector according to any one of claims 1 to 5, wherein an inner diameter of the reflector is constant in an axial direction.   The lens with a reflector according to any one of claims 1 to 5, wherein an inner peripheral surface of the reflector is tapered. A printed wiring board;
A light emitting diode mounted on the printed wiring board;
A printed circuit board comprising: the lens with a reflector according to claim 1, which is adhered to the printed wiring board so as to surround the light emitting diode. A method of manufacturing a lens with a reflector used in a light emitting part of a sensor,
A reflector injection molding process for injection molding a cylindrical reflector composed mainly of synthetic resin;
A lens part injection molding step for injection molding a lens part mainly contained in a transparent synthetic resin, which is accommodated in the hole of the lifter,
The inner peripheral surface of the reflector has light reflectivity,
A method for manufacturing a lens with a reflector, wherein the reflector injection molding step and the lens portion injection molding step are performed by a multicolor molding method.

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