WO2018025479A1

WO2018025479A1 - Optical lens

Info

Publication number: WO2018025479A1
Application number: PCT/JP2017/020030
Authority: WO
Inventors: 充富田
Original assignee: 日本電気硝子株式会社
Priority date: 2016-08-01
Filing date: 2017-05-30
Publication date: 2018-02-08
Also published as: JP2018021946A

Abstract

Provided is an optical lens that allows easy checking of a position thereof during implementation and that has excellent long-term stability. An optical lens 1 having an optical axis direction y is characterized by being provided with: a substrate 2 having a first lens forming surface 2a, an upper surface 2d and a bottom surface 2c that are connected to the first lens forming surface 2a, and a first lens part 3 formed on the first lens forming surface 2a; and a metallization layer 5 formed on the bottom surface 2c of the substrate 2, wherein the bottom surface 2c of the substrate 2 has first and second edge parts 2c1, 2c2 opposing each other in a direction x perpendicular to the optical axis direction y, and the metallization layer 5 is not formed, on the bottom surface 2c and in the vicinities of the first and second edge parts 2c1, 2c2.

Description

Optical lens

The present invention relates to an optical lens.

In recent years, optical communication devices have attracted attention with the demand for higher speed communication. Optical lenses are used in such optical communication devices.

For example, Patent Document 1 below discloses an optical module in which a lens member is fixed on a mounting substrate with an adhesive. It is known that the optical axis height of the lens member can be aligned by using an adhesive having high adhesiveness for mounting the lens member. The following Patent Document 2 discloses a lens member in which a lens is incorporated in a metal barrel. A metallized layer is formed on the side surface of the lens barrel.

JP 2008-026462 A JP 2008-203418 A

In the optical module described in Patent Document 1, an adhesive containing an organic substance is used in a hermetically sealed optical module casing. Therefore, long-term stability may be impaired due to the influence of gas generated by the volatilization of organic substances contained in the adhesive.

The light emitted from the light source is slightly absorbed by the lens member even if the lens member is transparent. Thereby, the lens member generates heat. When the energy density of the irradiated light is high, the lens member becomes high temperature even with slight light absorption. In the optical module of Patent Document 1, the adhesive is heated and softened to the lens member that has reached a high temperature, and the lens member may be displaced. Further, the lens member may be peeled off from the mounting substrate.

In recent years, there has been a demand for further miniaturization of lens members. In the case of the lens barrel of the lens member described in Patent Document 2, for example, a size of about 1 mm ³ or less is required. It is very difficult to incorporate a lens in such a small lens barrel with high accuracy.

Even when the lens member of Patent Document 2 is a glass-only molded body that does not include a metal lens barrel, a metallized layer is formed on the side surface of the lens member. In this lens member manufacturing process, the metallized layer is continuously formed on the side surfaces of a plurality of lens members arranged in close contact with each other. In each lens member, the metallized layer reaches the edge of the surface on which the metallized layer is formed. Therefore, when the position of the lens member is confirmed by the camera after the lens member is arranged on the mounting substrate, the position of the edge portion may be difficult to be recognized by the reflected light from the metallized layer at the edge portion. Thus, it may be difficult to confirm the position of the lens member.

Furthermore, when forming the metallized layer, in the step of arranging small lens members without gaps, the lens members may be chipped or cracked due to contact between the lens members. Long-term stability may be impaired by crack growth or the like.

An object of the present invention is to provide an optical lens capable of easily confirming a position at the time of mounting and having excellent long-term stability.

The optical lens according to the present invention is an optical lens having an optical axis direction, and has a lens forming surface, a top surface and a bottom surface connected to the lens forming surface, and a lens portion formed on the lens forming surface. And a metallized layer formed on the bottom surface of the substrate, the bottom surface of the substrate having first and second edge portions facing each other in a direction perpendicular to the optical axis direction. In the bottom surface, the metallized layer is not formed in the vicinity of the first and second edge portions.

In the present invention, the length of the region where the metallized layer is not formed in the direction perpendicular to the optical axis direction is preferably 5% or more and 20% or less of the length in the same direction of the bottom surface.

In the present invention, a light shielding film or a light absorbing film may be formed on the upper surface of the base material so as to overlap at least the entire surface of the metallized layer in plan view. In this case, it is preferable that the light-shielding film or the light absorption film is also formed outside the outer peripheral edge of the metallized layer in plan view.

According to the present invention, it is possible to provide an optical lens capable of easily confirming the position at the time of mounting and having excellent long-term stability.

FIG. 1 is a schematic bottom view showing an optical lens according to the first embodiment of the present invention. FIG. 2 is a schematic front view showing the optical lens according to the first embodiment of the present invention. FIG. 3 is a schematic bottom view showing an optical lens of a comparative example. FIG. 4 is a schematic front view showing an optical lens according to a first modification of the first embodiment of the present invention. FIG. 5 is a schematic bottom view showing an optical lens according to a second modification of the first embodiment of the present invention. FIGS. 6A and 6B are schematic cross-sectional views for explaining an example of the manufacturing method of the optical lens according to the first embodiment of the present invention. FIG. 7 is a schematic plan view for explaining an example of the manufacturing method of the optical lens according to the first embodiment of the present invention. FIG. 8 is a schematic side view for explaining an example of the manufacturing method of the optical lens according to the first embodiment of the present invention. FIG. 9 is a schematic front view showing an optical lens according to the second embodiment of the present invention. FIG. 10 is a schematic plan view showing an optical lens according to the second embodiment of the present invention. FIG. 11 is a schematic plan view showing an optical lens according to the third embodiment of the present invention.

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Moreover, in each drawing, the member which has the substantially the same function may be referred with the same code | symbol.

(First embodiment)
FIG. 1 is a schematic bottom view showing an optical lens according to the first embodiment of the present invention. FIG. 2 is a schematic front view showing the optical lens according to the first embodiment. In FIG. 1 and FIG. 2, a metallized layer to be described later is indicated by hatching. The same applies to FIGS. 3 to 5, 8, and 9 to be described later.

As shown in FIG. 1, the optical lens 1 according to the present embodiment has an optical axis direction y. The optical lens 1 includes a base material 2 having first and second

lens forming surfaces

2a and 2b facing each other in the optical axis direction y. A first lens portion 3 is formed on the first lens forming surface 2a, and a second lens portion 4 is formed on the second lens forming surface 2b. In the present embodiment, the first and

second lens portions

3 and 4 are convex lenses. In addition, the optical lens 1 should just have at least 1 lens part.

The substrate 2 has a bottom surface 2c connected to the first and second

lens forming surfaces

2a and 2b. The bottom surface 2c includes first and second edge portions 2c1 and 2c2 that face each other in a direction x perpendicular to the optical axis direction y. The bottom surface 2c has third and fourth end edges 2c3 and 2c4 connecting the first and second end edges 2c1 and 2c2. The third edge 2c3 is located on the first lens forming surface 2a side, and the fourth edge 2c4 is located on the second lens forming surface 2b side. The direction x is a direction parallel to the bottom surface 2c.

As shown in FIG. 2, the base material 2 has an upper surface 2d that faces the bottom surface 2c. The upper surface 2d has first and second edge portions 2d1 and 2d2 that face each other in the direction x. In the present embodiment, the first edge portions 2d1 and 2c1 of the upper surface 2d and the bottom surface 2c overlap each other in plan view. The second end edges 2d2 and 2c2 of the upper surface 2d and the bottom surface 2c also overlap.

Here, the dimension along the direction x of the optical lens 1 is defined as the width, and the dimension along the direction z perpendicular to the optical axis direction y and the direction x is defined as the height. At this time, in this embodiment, the optical lens 1 has a width of 1 mm and a height of 1 mm. The size of the optical lens 1 is not particularly limited.

The base material 2 can be comprised with glass, ceramics, a semiconductor, resin, etc., for example. But it is preferable that the base material 2 consists of glass. Examples of the glass used for the substrate 2 include B ₂ O ₃ —ZnO—La ₂ O ₃ glass, TeO ₂ —B ₂ O ₃ —WO ₃ —La ₂ O ₃ glass, and the like.

The transmittance of light having a wavelength of 400 nm to 1600 nm of the substrate 2 is preferably 70% or more, more preferably 80% or more, further preferably 90% or more, particularly preferably 95% or more, and most preferably 99% or more. When the transmittance is less than 70%, the light collection efficiency tends to decrease due to light scattering and absorption.

The metallized layer 5 is formed on the bottom surface 2c of the substrate 2. The metallized layer 5 has an outer peripheral edge 5g. The optical lens 1 is bonded to a mounting substrate for an optical device or the like via the metallized layer 5. The optical lens 1 can be bonded to a mounting substrate or the like by melting the metallized layer 5 by, for example, laser light irradiation. In the present embodiment, the metallized layer 5 is a laminated metal film in which a plurality of metal films are laminated. More specifically, the metallized layer 5 is a laminated metal film in which a Cr layer, a Pd layer, and an AuSn alloy layer are laminated in this order from the bottom surface 2c side. A Ni layer, a Ti layer, or a Pt layer may be used instead of or in addition to the Pd layer. In addition, the kind of metal which comprises the metallization layer 5 is not limited above.

The thickness of the metallized layer 5 is preferably 0.2 μm or more, and more preferably 0.5 μm or more. Thereby, a sufficient bonding force can be obtained. The thickness of the metallized layer 5 is preferably 2.0 μm or less. Thereby, the inclination of the optical lens 1 at the time of joining can be suppressed.

The arithmetic average roughness (Ra) of the bottom surface 2c of the substrate 2 is preferably 0.005 μm or more, more preferably 0.007 μm or more, and further preferably 0.010 μm or more. Thereby, the contact area between the bottom surface 2c and the metallized layer 5 can be increased, and the bonding force can be further increased. Even if the thickness of the metallized layer 5 is reduced, the bonding force can be sufficient, so that the inclination of the optical lens 1 during bonding can be suppressed.

The arithmetic average roughness (Ra) of the bottom surface 2c of the substrate 2 is preferably 2.0 μm or less, more preferably 1.5 μm or less, and even more preferably 1.0 μm or less. As a result, problems such as difficulty in press molding of the first and

second lens portions

3 and 4 hardly occur.

The arithmetic average roughness (Ra) of the upper surface 2d of the substrate 2 is preferably 2.0 μm or less, more preferably 1.5 μm or less, and even more preferably 1.0 μm or less. In this case, problems such as difficulty in press molding of the first and

second lens portions

3 and 4 hardly occur. In addition, in this specification, arithmetic mean roughness (Ra) shows arithmetic mean roughness (Ra) prescribed | regulated in JISB0601: 2013.

The bottom surface 2c includes a first metallized layer non-formation region A1 located in the vicinity of the first edge 2c1, and a second metallization layer non-formation region A2 located in the vicinity of the second edge 2c2. Have. The metallized layer 5 is not formed in the first and second metallized layer non-forming regions A1 and A2. In the present embodiment, the metallized layer 5 does not reach the third and fourth edge portions 2c3 and 2c4.

The feature of the present embodiment is that the metallized layer 5 is formed on the bottom surface 2c, and the bottom surface 2c has first and second metallized non-formation regions A1 and A2. As a result, the position can be easily confirmed at the time of mounting, and the long-term stability is excellent. Details of this effect will be described below.

The optical lens 1 is arranged on a mounting substrate by a transport collet, for example, when mounted on a mounting substrate for an optical device. After being placed on the mounting substrate, the position of the optical lens 1 is confirmed by the camera from the upper surface 2d side. In general, the position of the object is confirmed based on the luminance difference between the object whose position is to be confirmed and its surroundings. For example, a portion where the luminance difference exceeds a certain threshold is recognized as the outer periphery of the object. Note that in this specification, luminance refers to the intensity of light received by a camera. Below, this embodiment and the following comparative example are compared about the ease of performing the position confirmation by a camera.

FIG. 3 is a schematic bottom view showing an optical lens of a comparative example. In the optical lens 101 of the comparative example, the metallized layer 105 reaches the first and second end edges 2c1 and 2c2 of the bottom surface 2c of the base material 2. The metallized layer 105 reflects light strongly. When the optical lens 101 is imaged by the camera from the upper surface side of the substrate 2, the reflected light from the metallized layer 105 that has passed through the substrate 2 is also received by the camera. In the camera, the portion where the metallized layer 105 is formed and the periphery thereof are recognized as portions where the luminance is uniformly high. The high luminance portion includes the first and second end edges 2c1 and 2c2 of the bottom surface 2c, the first and second end edges of the top surface, and the periphery thereof. Therefore, the brightness difference between the first and second end edge portions 2c1 and 2c2 of the bottom surface 2c and the first and second end edge portions of the upper surface and the periphery thereof does not increase, and the position of the optical lens 101 is confirmed. hard.

On the other hand, in the present embodiment shown in FIGS. 1 and 2, since the metallized layer 5 is not formed in the first metallized layer non-forming region A1, in the vicinity of the first edge 2c1, Light is not reflected by the metallized layer 5. Thereby, the brightness | luminance difference between 1st edge part 2d1, 2c1 of the upper surface 2d and the bottom face 2c, and its circumference | surroundings can be enlarged. Accordingly, the positions of the first edge portions 2d1 and 2c1 can be easily recognized. Similarly, since the metallized layer 5 is not formed in the second metallized layer non-forming region A2, the positions of the second edge portions 2d2 and 2c2 can be easily recognized. Therefore, the position of the optical lens 1 at the time of mounting can be easily confirmed.

The length of the first metallized layer non-forming region A1 along the direction x from the first edge 2c1 is preferably 5% or more of the length along the direction x of the bottom surface 2c. The length of the second metallized layer non-forming region A2 along the direction x from the second edge 2c2 is preferably 5% or more of the length along the direction x of the bottom surface 2c. Thereby, the position of the optical lens 1 at the time of mounting can be confirmed more reliably.

The length of the first metallized layer non-forming region A1 along the direction x from the first edge 2c1 is preferably 20% or less of the length along the direction x of the bottom surface 2c, preferably 10% or less. It is more preferable that The length along the direction x from the second end edge 2c2 of the second metallized layer non-forming region A2 is preferably 20% or less of the length along the direction x of the bottom surface 2c, and is preferably 10% or less. It is more preferable that Thereby, the bonding force of the optical lens 1 to the mounting substrate or the like can be increased.

The length of the shortest portion along the direction x from the first edge 2c1 of the first metallized layer non-forming region A1 is preferably 10 μm or more and 200 μm or less, preferably 20 μm or more, More preferably, it is 100 μm or less. The length of the shortest portion along the direction x from the first edge 2c2 of the second metallized layer non-formation region A2 is preferably 10 μm or more and 200 μm or less, preferably 20 μm or more and 100 μm or less. It is more preferable that Thereby, the position of the optical lens 1 at the time of mounting can be confirmed more reliably, and the bonding force at the time of mounting can be increased.

Since the optical lens 1 can be bonded to the mounting substrate through the metallized layer 5, it can be mounted without using an adhesive containing an organic substance. Therefore, the optical lens 1 is excellent in long-term stability when mounted.

The ratio of the area of the metallized layer 5 to the area of the bottom surface 2c when viewed from the bottom surface 2c side of the substrate 2 is preferably 36% or more, and more preferably 50% or more. Thereby, the bonding force of the optical lens 1 to the mounting substrate or the like can be increased. The ratio of the area of the metallized layer 5 to the area of the bottom surface 2c is preferably 95% or less, and more preferably 90% or less. Thereby, the position of the optical lens 1 at the time of mounting can be easily confirmed. In order to increase the bonding force of the optical lens 1 to the mounting substrate or the like, it is preferable to bond the optical lens 1 while applying a load. By limiting the ratio of the area of the metallized layer 5 to the area of the bottom surface 2c to 95% or less as in the present invention, the metallized layer 5 can be optically bonded even when bonded to a mounting substrate or the like while applying a load to the optical lens 1. It is possible to prevent leakage from the lens 1.

The base material 32 may be chamfered like the 1st modification of 1st Embodiment shown in FIG. The base material 32 has

side surfaces

32e and 32f that are connected to the bottom surface 32c and the first lens forming surface 32a and that face each other. In the first modification, the chamfered portion of the bottom surface 32c and the portion where the side surfaces 32e and 32f are connected are the first and second end edge portions 32c1 and 32c2. In the first modified example, since the chamfer is chamfered, chipping of the base material 32 hardly occurs.

In the first embodiment shown in FIG. 1, the metallized layer 5 does not reach the third and fourth edge portions 2c3 and 2c4 of the bottom surface 2c, but the second modification of the first embodiment shown in FIG. As described above, the metallized layer 45 may reach the third and fourth edge portions 2c3 and 2c4.

Hereinafter, an example of a method for manufacturing the optical lens 1 according to the first embodiment will be described.

(Production method)
FIG. 6A and FIG. 6B are schematic cross-sectional views for explaining an example of the manufacturing method of the optical lens according to the first embodiment. FIG. 7 is a schematic plan view for explaining an example of the manufacturing method of the optical lens according to the first embodiment. FIG. 8 is a schematic side view for explaining an example of the manufacturing method of the optical lens according to the first embodiment. In addition, the side surface in FIG. 8 shows the metallized layer formation surface mentioned later.

As shown in FIG. 6A, a mother substrate 2A having first and second main surfaces 2Aa and 2Ab is prepared. Next, press molding of the mother substrate 2A is performed using the

molds

7A and 7B. Thereby, as shown in FIG. 6B, a plurality of first lens portions 3 are formed on the first main surface 2Aa of the mother substrate 2A, and a plurality of second lens portions are formed on the second main surface 2Ab. 4 is formed.

The first and

second lens portions

3 and 4 may be formed in a portion other than the cross section shown in FIG. 6B, for example, as shown in FIG. In this case, dicing is performed along the dicing line II. Dicing may be performed using, for example, a dicing saw or the like, or may be performed by laser scribing. Thereby, a metallized layer forming surface is formed.

The metallized layer forming surface is a surface corresponding to the bottom surface 2c of the optical lens 1 of the first embodiment shown in FIG. Blasting or the like may be performed on the metallized layer forming surface so that the metallized layer forming surface has an arithmetic average roughness (Ra) within the above-described range.

Next, as shown in FIG. 8, a plurality of metallized layers 5 are formed on the metallized layer forming surface 2Ac. A plurality of metallized layers 5 are formed so that the outer peripheral edge 5g of each metallized layer 5 does not reach the outer peripheral edges of the dicing line II-II and the mother substrate 2A. The metallized layer 5 can be formed by, for example, a sputtering method or a vapor deposition method. At this time, for example, a resist pattern may be formed on the metallized layer forming surface 2Ac by a photolithography method, and the plurality of metallized layers 5 may be formed using the resist pattern.

Next, dicing is performed along the dicing line II-II. Dicing may be performed using, for example, a dicing saw or the like, or may be performed by laser scribing. Thereby, a plurality of optical lenses 1 can be obtained.

(Second Embodiment)
FIG. 9 is a schematic front view showing an optical lens according to the second embodiment. FIG. 10 is a schematic plan view showing an optical lens according to the second embodiment. In FIGS. 9 and 10, a light shielding film described later is indicated by broken-line hatching.

As shown in FIG. 9, the optical lens 11 is different from the first embodiment in that a light shielding film 16 is formed on the upper surface 2d of the substrate 2. Except for the above points, the optical lens 11 has the same configuration as the optical lens 1 according to the first embodiment.

For the light shielding film 16, for example, an appropriate metal or semiconductor can be used. Examples of metals include Cr, Ti, Ni, Al and the like. Examples of semiconductors include Ge and Si.

As shown in FIG. 10, the light shielding film 16 is formed so as to overlap the entire surface of the metallized layer 5 in plan view. Thereby, when the position is confirmed by the camera from the upper surface 2d side, the reflected light from the metallized layer 5 toward the camera side can be shielded by the light shielding film 16. Therefore, the luminance difference between the first and second end edges 2d1, 2c1, 2d2, and 2c2 of the top surface 2d and the bottom surface 2c shown in FIG. Therefore, the position of the optical lens 11 at the time of mounting can be confirmed more reliably.

The light shielding film 16 is preferably formed so as to overlap at least part of the first and second metallized layer non-forming regions A1 and A2 in plan view. More preferably, the light shielding film 16 is also formed outside the outer peripheral edge 5g of the metallized layer 5 in a plan view as in the present embodiment. As a result, the reflected light from the metallized layer 5 toward the camera can be more reliably shielded.

In the present embodiment, the light shielding film 16 does not reach the first and second end edges 2d1 and 2d2 of the upper surface 2d. This makes it easier to confirm the position of the optical lens 11 during mounting.

Also in this embodiment, similarly to the first embodiment, the optical lens 11 can be mounted without using an adhesive containing an organic substance. Therefore, the optical lens 11 is excellent in long-term stability when mounted.

(Third embodiment)
FIG. 11 is a schematic plan view showing an optical lens according to the third embodiment. In FIG. 11, a light absorption film described later is indicated by broken line hatching.

As shown in FIG. 11, the optical lens 21 is different from the second embodiment in that a light absorbing film 26 is formed on the upper surface 2d of the substrate 2. Except for the above points, the optical lens 21 has the same configuration as the optical lens 11 according to the second embodiment.

For the light absorption film 26, for example, an appropriate semiconductor or nitride can be used. Examples of semiconductors include Ge and Si. Examples of nitrides include AlN, SiN, and CrN.

In the present embodiment, the light absorbing film 26 is disposed at the same position as the light shielding film 16 in the second embodiment. More specifically, the light absorption film 26 is formed so as to overlap the entire surface of the metallized layer 5 in plan view. Accordingly, when the position is confirmed by the camera from the upper surface 2d side, the reflected light from the metallized layer 5 toward the camera side is absorbed by the light absorption film 26. Therefore, it is possible to block the reflected light toward the camera side. Therefore, as in the second embodiment, the position of the optical lens 21 at the time of mounting can be confirmed more reliably.

The light absorbing film 26 is preferably formed so as to overlap at least part of the first and second metallized layer non-forming regions A1 and A2 in plan view. More preferably, as in the present embodiment, it is desirable that the light absorption film 26 is also formed outside the outer peripheral edge 5g of the metallized layer 5 in plan view. As a result, the reflected light from the metallized layer 5 toward the camera can be more reliably shielded.

In the present embodiment, the light absorption film 26 does not reach the first and second end edges 2d1 and 2d2 of the upper surface 2d. This makes it easier to check the position of the optical lens 21 during mounting.

Also in this embodiment, similarly to the first embodiment, the optical lens 21 can be mounted without using an adhesive containing an organic substance. Therefore, the optical lens 21 is excellent in long-term stability when mounted.

DESCRIPTION OF SYMBOLS 1 ... Optical lens 2 ...

Base material

2a, 2b ... 1st, 2nd lens formation surface 2c ... Bottom surface 2c1-2c4 ... 1st-4th edge part 2d ... Upper surface 2d1, 2d2 ... 1st, 2nd Edge portion 2A ... Mother substrates 2Aa, 2Ab ... First and second main surfaces 2Ac ... Metallized

layer forming surfaces

3, 4 ... First and second lens parts 5 ... Metalized layer 5g ... Outer

peripheral edges

7A, 7B ... Molded Mold 11 ... Optical lens 16 ... Light shielding film 21 ... Optical lens 26 ... Light absorption film 32 ... Base material 32a ... First lens forming surface 32c ... Bottom surface 32c1, 32c2 ... First and

second edge portions

32e, 32f ... Side 45 ... Metallized layer 101 ... Optical lens 105 ... Metallized layer

Claims

An optical lens having an optical axis direction,
A substrate having a lens forming surface, and an upper surface and a bottom surface connected to the lens forming surface, and having a lens portion formed on the lens forming surface;
A metallized layer formed on the bottom surface of the base material,
The bottom surface of the base material has first and second edge portions facing each other in a direction perpendicular to the optical axis direction, and the metallization is provided in the vicinity of the first and second edge portions on the bottom surface. An optical lens in which no layer is formed.
2. The optical lens according to claim 1, wherein a length of a region where the metallized layer is not formed in a direction perpendicular to the optical axis direction is not less than 5% and not more than 20% of a length in the same direction of the bottom surface. .
The optical lens according to claim 1, wherein a light shielding film or a light absorbing film is formed on the upper surface of the base material so as to overlap at least the entire surface of the metallized layer in a plan view.
4. The optical lens according to claim 3, wherein the light shielding film or the light absorbing film is also formed outside the outer peripheral edge of the metallized layer in a plan view.