TWI446083B - Optical filter element and method for manufacturing same, camera module and portable electronic device - Google Patents

Description

Filter element and manufacturing method thereof, camera module and portable electronic device

The present invention relates to a filter element, a method of manufacturing the same, a camera module using the filter element, and a portable electronic device using the same.

With the development of camera technology, the combination of lens modules and various portable electronic devices such as mobile phones, video cameras, computers, etc., has been favored by many consumers, so the market demand for miniaturized lens modules has increased.

At present, the miniaturized lens module uses a precision mold and other processes to manufacture micro-optical components, and then electrically connects, packages, and then cuts the image sensor made of the silicon wafer to obtain a camera module. However, as the lens module is becoming more and more miniaturized, the current process is increasingly unable to meet the precision requirements of micro-optical components, and the processes of yellow light, lithography, etching, etc., which are often used in the process, have a great influence on the environment.

In view of the above, it is necessary to provide a filter element that can better adapt to the trend of miniaturization of the lens module, and that is inexpensive and environmentally friendly, a manufacturing method thereof, a camera module using the filter element, and A portable electronic device using the camera module.

A filter element comprising a transparent substrate and a membrane filter disposed on the transparent substrate a light sheet, wherein: further comprising a metal film layer coated on the surface of the film filter, the geometric center of the metal film layer is further provided with a light passing hole for illuminating external light The film filter.

A method of manufacturing a filter element, comprising: providing a transparent substrate; coating at least one layer of ceramic powder on the transparent substrate, and initially hardening each layer of ceramic powder by laser hardening; ceramic powder after preliminary hardening a UV hardening resin is disposed on the geometric center of the upper surface of the body, and the UV hardening resin is hardened; the surface of the initially hardened ceramic powder is plated with a metal thin film layer by continuous sputtering, and the thickness of the metal thin film layer is less than or equal to curing The thickness of the UV-curable resin; the UV-curing resin is wiped with alcohol to form a light-passing hole; the transparent substrate is placed in a high-temperature environment to deeply harden the ceramic powder, and the temperature in the high-temperature environment is higher than the temperature at which the laser is initially hardened. The ceramic powder is completely removed to form a cavity having the transparent substrate as a base and the metal thin film layer as a wall; and a thin film filter is formed inside the cavity by ion plating.

A camera module includes a lens module and a sensor disposed opposite to the lens module, further comprising: a filter element disposed at an end of the lens module near the object side, and The lens modules are on the same optical axis.

A portable electronic device includes an electronic device body and a camera module disposed on the electronic device body, the camera module including a filter element.

Compared with the prior art, the filter element and the manufacturing method thereof provided by the present invention eliminate the need for a camera module at the wafer level by using a ceramic powder as a sacrificial material to harden the ceramic powder by laser method. The process of manufacturing the filter element provided by the invention can better adapt to the trend of the lens module to be more miniaturized, the process is simple, and the cost is low. The invention is also inexpensive and environmentally friendly, and the invention also relates to a camera module using the filter element and a portable electronic device using the same.

10‧‧‧ Filter elements

11‧‧‧Transparent substrate

12, 27‧‧‧ film filter

13, 25‧‧‧ metal film layer

14, 26‧‧ ‧ light hole

131, 251‧‧‧ chromium nitride coating

132, 252‧‧‧ copper film

133, 253‧‧‧Stainless steel film layer

20‧‧‧Transparent substrate

21, 21a‧‧‧Ceramic powder layer

22‧‧‧Laser head

23, 23a‧‧‧Preliminary hardening layer of ceramic powder

24‧‧‧UV hardening resin

40‧‧‧Electronic devices

30, 42‧‧‧ camera module

31‧‧‧ Filter elements

32‧‧‧Lens module

33‧‧‧ Sensors

41‧‧‧Electronic device body

1 is a schematic structural view of a filter element provided in an embodiment of the present invention.

2 is a flow chart showing a method of manufacturing a filter element provided in an embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a camera module provided in an embodiment of the present invention.

4 is a schematic diagram of a portable electronic device provided in an embodiment of the present invention.

The invention will now be described in further detail with reference to the accompanying drawings.

Referring to FIG. 1 , a filter element 10 according to an embodiment of the present invention includes a transparent substrate 11 , a thin film filter 12 , a metal thin film layer 13 , and a light passing hole 14 .

The transparent substrate 11 is a glass substrate. It can be understood that the transparent substrate 11 can be made of any light transmissive material, and can function to allow light emitted by an external light source to penetrate the transparent substrate 11.

The thin film filter 12 is an infrared light cut filter disposed on the transparent substrate 11 and has an inverted T-shaped cross section. It can be understood that the thin film filter 12 can also be an ultraviolet cut filter or the like. Other types of thin film filters, and which can be formed into other shapes according to actual needs, such as a cross section which may be a rectangular or square shape which is the same width as the transparent substrate 11.

The metal thin film layer 13 is coated on the surface of the thin film filter 12. In this embodiment, the metal thin film layer 13 is a multi-layer structure, which is coated on the side of the transparent substrate 11 and the membrane filter. The surface of the light sheet 12 is a chromium nitride film layer 131, a copper film layer 132, and a stainless steel film layer 133 in this order from the surface of the film filter 12. Here, the chromium nitride film layer 131 is used as a light blocking layer, which prevents external stray light from entering the filter element, and the copper film layer 132 and the stainless steel film layer 133 are used as an electromagnetic interference preventing film. It can be understood that the metal thin film layer 13 can also be a single layer structure, and the material thereof can also be other metals having different functional uses, and the metal thin film layer 13 can also be coated only on the surface of the thin film filter 12.

The light passing hole 14 is disposed at a geometric center of the metal thin film layer 13 opposite to the transparent substrate 11 for irradiating external light into the thin film filter 12.

Referring to FIG. 2, a method for manufacturing a filter element according to the present invention includes the following steps.

(1) A transparent substrate 20 is provided.

The transparent substrate 20 is a glass substrate.

(2) Applying at least one layer of ceramic powder 21 on the transparent substrate, and each layer of the ceramic powder is preliminarily hardened by laser hardening.

The ceramic powder 21 is a mixture of aluminum phosphate, cerium oxide and water, which is applied onto the transparent substrate 20 by spin coating.

The transparent substrate 20 coated with the ceramic powder layer 21 is placed under a plurality of laser heads 22, and the ceramic powder layer 21 is preliminarily hardened to form a ceramic powder preliminary hardening layer 23 on the transparent substrate 20. The laser hardening temperature range may be [100 ° C, 200 ° C], and in the present invention, the laser hardening temperature is 130 ° C.

Applying a layer of the ceramic powder on the preliminary hardened layer 23 by spin coating The ceramic powder layer 21 is hardened by laser irradiation, and the purpose thereof is to make the filter element produced by the present invention reach a certain height, so this step can be repeated according to actual needs. Further, from the second ceramic powder layer 21, the range of laser hardening may be all ceramic powder layers, or may be a partial ceramic powder layer, which is determined according to the outer shape of the filter element to be actually produced. For example, when the shape of the filter element is cylindrical, the ceramic powder layer of each layer will be completely hardened, and when the shape of the filter element is stepped, the ceramic powder layer of each layer will be partially as needed. The hardened, partially hardened ceramic powder is cleaned and removed with pure water before the next layer of ceramic powder is applied.

In this embodiment, five layers of ceramic powder layers are co-coated on the transparent substrate 20. Starting from the second layer of ceramic powder layers, each layer of the ceramic powder body 21 is applied to the center of the ceramic powder layer. The hardened layer 23a of the ceramic powder is formed by laser hardening, and the unhardened ceramic powder 21a is removed by washing with pure water before the next layer of the ceramic powder layer is applied.

(3) A UV hardening resin 24 is provided on the geometric center of the upper surface of the ceramic powder preliminary hardened layer 23a, and the UV hardening resin 24 is cured.

(4) A metal thin film layer 25 is formed by continuous sputtering on the surface of the ceramic powder preliminary hardened layer 23a, and the thickness of the metal thin film layer 25 is less than or equal to the thickness of the cured UV hardening resin 24.

In this embodiment, the metal thin film layer 25 is coated on the side surface of the transparent substrate 20 and the surface of the ceramic powder preliminary hardening layers 23 and 23a, and is sequentially outward from the surface of the ceramic powder preliminary hardening layers 23 and 23a. The chromium nitride film layer 251, the copper film layer 252, and the stainless steel film layer 253 have a total thickness less than or equal to the thickness of the UV curable resin 24. Wherein, the chromium nitride film layer 251 is used as a light blocking layer, which can prevent the outside The coming stray light enters the filter element; the copper film layer 252 and the stainless steel film layer 253 are used as an anti-electromagnetic interference film. It is to be understood that the metal thin film layer 25 may also be applied only to the surface of the ceramic powder preliminary hardened layer 23a.

(5) The UV-curable resin 24 is erased with alcohol to form a light-passing hole 26.

(6) The ceramic substrate preliminary hardening layers 23 and 23a are deeply hardened by placing the transparent substrate 20 in a high temperature environment, and the temperature of the high temperature environment is higher than the temperature at which the laser is initially hardened; in the present invention, the high temperature environment It is provided by a high temperature furnace, and the temperature range in which the ceramic powder preliminary hardened layers 23 and 23a are hardened is [250 ° C, 1000 ° C]. In the present embodiment, preferably, the temperature at which the ceramic powder preliminary hardening layers 23 and 23a are subjected to deep hardening is 250 °C.

(7) The deep-hardened ceramic powder hardened layers 23 and 23a are all removed to form a cavity 50 having the transparent substrate 20 as a base and the metal thin film layer 25 being a wall.

By deepening the ceramic powder preliminary hardened layers 23 and 23a, the bonding force between the ceramic powder hardened layers 23 and 23a and the metal thin film layer 25 plated thereon can be weakened, and the ceramic powder can also be weakened. The bonding force between the hardened layers 23 and 23a and the transparent substrate 20 enables the ceramic powder hardened layers 23 and 23a to be easily removed in a subsequent cleaning process to form a transparent substrate 20 as a base. The metal thin film layer 25 is a cavity 50 having a light-passing hole 26 at its top end.

(8) A thin film filter 27 is formed inside the cavity 50 by ion plating.

In the present embodiment, the thin film filter 27 is an infrared light cut filter (IR-Cut) film. It can be understood that the type of the thin film filter 27 can be changed according to different requirements. For example, the thin film filter 27 can also be an ultraviolet cut filter.

In order to avoid coating the outer layer of the cavity 50 with the thin film filter 27 during ion assist plating, the outer layer of the cavity 50 may be coated by spin coating after the step (7) is completed. A layer of ceramic powder is then subjected to step (8). After the completion of the step (8), the ceramic powder coated on the outer layer of the cavity 50 is removed using pure water.

The invention also provides a camera module having the filter element and an electronic device using the same.

Referring to FIG. 3 , the camera module 30 of the present invention includes a filter element 31 , a lens module 32 , and a sensor 33 .

The filter element 31 may be any one of the filter elements provided in the above embodiments. The filter element 31 is disposed at an end portion of the lens module 32 near the object side, and is fixed to the lens module 32 by a UV curing resin.

The lens module 32 includes a plurality of lenses, and an optical axis of the lens module 32 coincides with an optical axis of the filter element 31.

The sensor 33 is disposed opposite to the lens module 32. External light is irradiated through the filter element 31, and then incident on the sensor 33 through the lens module 32.

It can be understood that, in the present invention, the type of the lens module 32 and the sensor 33 and the packaging manner may be any ones appearing in the prior art.

Referring to FIG. 4 , the electronic device 40 of the present invention includes a body 41 and a camera module 42 . The camera module 42 is disposed on the body 41 .

In this embodiment, the electronic device 40 is a mobile phone, and the camera module 42 can be any one of the camera modules provided in the foregoing embodiments.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. please. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

30‧‧‧ camera module

31‧‧‧ Filter elements

32‧‧‧Lens module

33‧‧‧ Sensors

Claims (12)

A filter element includes a transparent substrate and a thin film filter disposed on the transparent substrate, wherein the filter element further comprises a metal thin film layer disposed on an outer surface of the thin film filter The metal film layer is further provided with a light passing hole for irradiating external light into the film filter. The filter element of claim 1, wherein the transparent substrate is a glass substrate. The filter element of claim 2, wherein the metal thin film layer comprises a chromium nitride film layer, a copper film layer and a stainless steel film layer disposed in order from the film filter. The filter element of claim 3, wherein the film filter is an infrared light cut filter. A method of manufacturing a filter element, comprising: (1) providing a transparent substrate; (2) applying at least one layer of ceramic powder on the transparent substrate, and each layer of ceramic powder is initially hardened by laser hardening; 3) providing a UV hardening resin at a predetermined position on the upper surface of the ceramic powder after the preliminary hardening, and hardening the UV hardening resin; (4) plating the metal thin film on the surface of the preliminary hardened ceramic powder by continuous sputtering a layer, the thickness of the metal film layer is less than or equal to the thickness of the UV-curable resin after curing; (5) erasing the UV-curable resin with alcohol to form a light-passing hole; (6) placing the transparent substrate in a high-temperature environment for the ceramic The powder is subjected to deep hardening, and the temperature of the high temperature environment is higher than the temperature preliminarily hardened by laser; (7) the ceramic powder is completely removed to form a cavity with the transparent substrate as the bottom and the metal thin film layer as the wall; (8) A thin film filter is formed inside the cavity by ion plating. The method of manufacturing a filter element according to claim 5, wherein the method of manufacturing the filter element further comprises performing a ceramic powder coating step between the step (7) and the step (8), The step is for applying a ceramic powder to the outer layer of the cavity, and the ceramic powder is washed and removed with pure water after the completion of the step (8). The method for manufacturing a filter element according to claim 5, wherein the part or all of the ceramic powder layer is initially hardened by laser hardening from the second layer of ceramic powder. The hardened portion of the ceramic powder is washed and removed with pure water. The method of producing a filter element according to claim 7, wherein the ceramic powder layer is applied by a spin coating method. The method of manufacturing a filter element according to claim 8, wherein the laser hardening temperature range is [100 ° C, 200 ° C]. The method of manufacturing a filter element according to claim 9, wherein the ceramic powder has a hardening temperature range of [250 ° C, 1000 ° C] in the high temperature furnace. A camera module comprising a lens module and a sensor disposed opposite to the lens module, further comprising: a filter element according to any one of claims 1 to 4, wherein the filter element The component is disposed at an end of the lens module near the object side and is on the same optical axis as the lens module. A portable electronic device includes an electronic device body and a camera module as set forth in claim 11 of the electronic device body.