TWI784175B - Method for forming optical wall by laser engraving an opening and optical wall structure - Google Patents

Abstract

The invention provides an optical wall structure, which includes a substrate, a first wall layer, a laser shielding copper layer and a second wall layer. The first wall layer is formed on a working surface of the substrate and defines a first opening exposing the working surface. The laser shielding copper layer is formed not on a side wall surrounding the first opening but on a top surface of the first wall layer. The second wall layer is formed on the laser shielding copper layer and defines a second opening. The second wall layer has a cross-section area smaller than the first wall layer. The second opening has a contour wider that the first opening, and the second opening exposes a part of the laser shielding layer. The present invention also provides a method for forming optical wall by laser engraving an opening.

Description

Method for Forming Optical Retaining Wall by Laser Opening and Structure of Optical Retaining Wall

The invention relates to a manufacturing method and structure of a photoelectric mechanism, in particular to a manufacturing method and structure for forming a retaining wall on the photoelectric mechanism.

The existing light sensor includes a light-emitting unit and a light-sensing unit. After the light emitted by the light-emitting unit is reflected by the object to be detected, the light-sensing unit can receive and output a sensing signal. In order to prevent the light emitted by the light-emitting unit from being directly transmitted to the photosensitive unit, the existing light sensor will set a barrier between the light-emitting unit and the photosensitive unit, so that the light-emitting unit can only emit light in a predetermined direction, and the photosensitive unit can only sense the light. Detect light from a predetermined direction, thereby increasing the reliability of the light sensor.

The retaining walls of existing photosensors are mostly formed by molding methods such as injection molding, but this process has its disadvantages: (1) It is easy to have glue overflow, thus reducing the yield; (2) It is easy to affect the accuracy due to mold shift, and it is not conducive to miniaturization; (3) It is necessary to make molds for different retaining wall shapes, thus increasing the cost.

In view of this, the main purpose of the present invention is to provide a photoelectric mechanism manufacturing process that can improve precision and reduce cost.

In order to achieve the above and other objects, the present invention provides a method for forming an optical barrier by laser opening, comprising: providing a substrate having a working surface; forming a first wall membrane on the working surface, the first wall membrane having a first wall area and a first non-wall area; Before the first wall film is laser engraved, a second wall film is formed on the first wall film, the second wall film has a second wall area and a second non-wall film area, the second wall area is located on the first wall area, and the cross-sectional area of the second wall area is not larger than that of the first wall area; The first and second non-blocking wall areas are removed by using a laser beam, and the first and second blocking wall areas are retained, wherein the first and second blocking wall areas enclose a window that exposes the working surface.

In order to achieve the above and other objectives, the present invention also provides an optical barrier structure, which includes a substrate, a first barrier layer, a laser shielding copper layer and a second barrier layer, the substrate has a working surface, the first A retaining wall layer is formed on the working surface, and the first retaining wall layer encloses a first opening of a bare working surface; the laser shielding copper layer is formed on an upper surface of the first retaining wall layer but not formed on the enclosure The side wall of the first opening; the second retaining wall layer is formed on the laser shielding copper layer, and the second retaining wall layer encloses a second opening, and the cross-sectional area of the second retaining wall layer is smaller than that of the first retaining wall layer , the contour of the second opening is larger than that of the first opening, and the second opening exposes a part of the laser shielding copper layer.

The retaining wall formed by the above method has high precision, reduces the processing cost, and improves the freedom of circuit design of the photoelectric mechanism. Even if the position or shape of the window is modified, it is not necessary to remake or modify the mold as in the prior art. Moreover, by forming a laser shielding copper layer between the barrier wall layers, multiple layers of barrier wall layers can have different profiles in one laser engraving operation, thereby greatly improving the degree of design freedom.

The present invention is a method for forming an optical barrier by opening a window with a laser and its optical barrier structure. The optical barrier structure can be applied to a light-emitting device, a photosensitive device, or a device that has both light-emitting and photosensitive functions, such as the prior art. The light sensor described above can be applied to but not limited to remote controllers and side distance meters.

One embodiment of the method for forming an optical barrier by laser opening is described below with reference to FIGS. 1 to 12 .

Please refer to Fig. 1, at first provide a substrate 10, it has a working surface 11, this substrate 10 can be the circuit board that prefabricated with the circuit or the lead frame that LED is used, for example, substrate 10 has insulating substrate and is formed on The circuit structure and electrical contacts of the insulating substrate, such as epoxy resin, glass cloth (woven glass), polyester or other materials commonly used in making circuit board substrates.

Next, please refer to FIG. 2, use a laminator to laminate a light-curable or heat-curable first barrier film 20 on the working surface 11, the dotted line shown in the figure represents the first barrier film 20 The boundary between a first wall area 21 and a first non-wall area 22, the first wall area 21 is, for example, ring-shaped, and at least a part of the first non-wall area 22 is surrounded by the first wall area 21 between. In the state shown in FIG. 1 , the first barrier film 20 is not fully cured, and at this moment, the first barrier region 21 and the first non-retainer region 22 have no substantial difference in chemical structure; After a barrier film 20 is formed on the working surface 11, it can be further cured by light or heat. Before being laminated on the working surface 11, the first barrier film 20 is pre-formed on a carrier film, for example, and the carrier film is removed after the first barrier film 20 is laminated on the working surface 11, so The carrier film can be polyethylene terephthalate (PET) or other polyester films, polyimide films, polyamideimide films, polypropylene films, polystyrene films. In a possible implementation, the first barrier film 20 is black and can absorb most of the light. In other possible implementation manners, the first retaining wall membrane may also be formed by coating uncured retaining wall slurry on the working surface by screen printing or other coating methods, and then curing it.

As shown in FIG. 3 , a laser shielding copper layer 30 is formed on the upper surface 201 of the first barrier film 20 by electroless plating, sputtering or other methods.

Next, as shown in FIG. 4 , a photoresist layer 31 is formed on the laser shielding copper layer 30 , and the photoresist layer 31 is selectively irradiated and exposed.

Next, as shown in FIG. 5 , the portion of the photoresist layer 31 opposite to the first non-blocking wall region 22 is selectively removed with a developer, exposing the underlying laser shielding copper layer 30 .

Then, as shown in FIG. 6, the portion of the laser-shielded copper layer 30 facing the first non-wall region 22 is selectively removed with an etchant, exposing the first wall layer 20 underneath, especially the exposed bottom layer. The first non-retaining wall area 22.

As shown in Figure 7, remove the photoresist layer.

As shown in FIG. 8, before the first wall film 20 is laser engraved and pre-cured, a light-curable or heat-curable second wall film 40 is formed on the first wall film 20. , wherein a part of the second barrier film 40 also covers the laser shielding copper layer 30 . Similar to the first wall film 20, the second wall film 40 also has a second wall area 41 and a second non-wall area 42, the second wall area 41 is located above the first wall area 21, and The cross-sectional area of the second wall area 41 is not larger than that of the first wall area 21 , that is, the profile of the second wall area 41 is equal to or smaller than that of the first wall area 21 . Similarly, before being laminated on the first wall film 20, the incompletely cured second wall film 40 is pre-formed on a carrier film, and the second wall film 40 is formed on the first wall film After 20, it can be further cured by light or heat. The carrier film can be removed after the second wall film 40 is laminated on the first wall film 20. The carrier film can be polyethylene terephthalic acid Polyester (PET) or other polyester film, polyimide film, polyamideimide film, polypropylene film, polystyrene film. In a possible implementation, the second barrier film 40 is also black to absorb most of the light. In other possible implementation manners, the second barrier wall membrane may also be formed by coating the uncured barrier wall slurry on the first barrier wall membrane by screen printing or other coating methods, and then curing.

As shown in Figure 9, a laser engraving machine is used to emit a laser beam to selectively remove the first and second non-blocking wall areas 22, 42, wherein, although part of the laser beam penetrates the second non-blocking wall Wall area 42, but because it is shielded by the laser shielding copper layer 30, it can no longer go deeper, thereby retaining the first wall area 21 under the laser shielding copper layer 30, forming the state shown in Figure 10, and staying The first and second retaining wall areas 21 and 41 are respectively used as the first and second retaining wall layers 20A and 40A, the first retaining wall layer 20A encloses a first opening 601, and the second retaining wall layer 40A encloses a The combination of the second window 602 and the first and second windows 601 and 602 forms a window 60 that can expose the working surface 11 . In this embodiment, the cross-sectional area of the second retaining wall layer 40A is smaller than that of the first retaining wall layer 20A, and the profile of the second opening 602 is larger than that of the first opening 601. or other agencies.

Next, as shown in Fig. 11, photoelectric units 70 are formed on the working surface 11 in the window 60. The number of photoelectric units 70 can be determined according to requirements, and the photoelectric units 70 are one of light-emitting units and photosensitive units, and the second 1. The barrier formed by the combination of the second barrier layer 20A, 40A and the laser shielding copper layer 30 is higher than the photoelectric unit 70 to block light. The photoelectric unit 70 can form an electrical connection with the circuit structure or electrical contacts on the substrate 10. The electrical connection is realized by, for example, wire bonding; when the photoelectric unit is a flip-chip LED or other appropriate situations , the wire bonding step can be omitted. The light-emitting unit is, for example, LED, and the photosensitive unit is, for example, CCD or CMOS. The light-emitting unit is used to emit light, and the photosensitive unit is used to sense light. The light can be visible light or invisible light, such as infrared light.

Next, as shown in FIG. 12, glue is dispensed in the window 60. The glue 80 is a light-transmitting glue, such as transparent glue or fluorescent glue, to protect the photoelectric unit 70 and/or to emit light. light of a preselected wavelength, that is, the prepared optical barrier structure has a substrate 10, a first barrier layer 20A with a first opening 601, and a first barrier layer 20A formed on the upper surface of the first barrier layer 20A but not The laser shielding copper layer 30 formed on the side wall surrounding the first opening 601, a second barrier layer 40A with the second opening 602, a photoelectric unit formed on the working surface 11 and located in the opening 60 70 , and a colloid 80 formed in the window 60 .

It should be noted that the foregoing embodiments only take two layers of retaining wall layers as an example. In other possible implementations of the present invention, more layers of retaining wall layers can also be formed by a similar multi-layer stacking method. For example, in In the embodiment shown in FIG. 13 , the prepared optical barrier structure has a substrate 10, a first barrier layer 20A with a first opening 601, and an upper surface of the first barrier layer 20A but The laser shielding copper layer 30 not formed on the sidewall surrounding the first opening 601, a second barrier layer 40A with the second opening 602, and a second barrier layer 40A formed on the upper surface but not formed The laser shielding copper layer 35 surrounding the side wall of the second opening 602, a third barrier layer 50A with the third opening 603, and a photoelectric unit 70 formed on the working surface 11 and located in the opening 60 , and a colloid 80 formed in the window 60 .

In summary, by forming a laser shielding copper layer between the retaining wall layers, multiple layers of retaining wall layers can have different profiles in one laser engraving operation, thereby greatly increasing the degree of freedom in design.

In other possible implementation manners, the laser intensity in the central area and the peripheral area of the laser beam can be adjusted so that the central area of the laser beam has a strong penetrating ability, so that the laser shielding copper layer is not set. Down, it can also form a stepped or gradually expanding window.

10: Substrate 11: Working surface 20: First Wall Membrane 20A: The first retaining wall layer 201: upper surface 21: The first wall area 22: The first non-retaining wall area 30, 35: laser shielding copper layer 31: photoresist layer 40:Second wall membrane 40A: Second retaining wall layer 41: Second retaining wall area 42: The second non-retaining wall area 50A: The third retaining wall layer 60: open window 601: First window opening 602: second window opening 603: The third window 70: photoelectric unit 80: colloid

1 to 12 are schematic diagrams of the manufacturing method of the first embodiment of the present invention.

Fig. 13 is another embodiment of the optical barrier structure of the present invention.

10: Substrate

11: Working surface

20A: The first retaining wall layer

30:Laser masking copper layer

40A: Second retaining wall layer

60: open window

601: First window opening

602: second window opening

70: photoelectric unit

80: colloid

Claims (7)

A method for forming an optical barrier by laser opening, comprising: providing a substrate with a working surface; forming a first barrier film on the working surface, the first barrier film having a first barrier wall area and a first non-wall area; before the first wall film is laser engraved, a second wall film is formed on the first wall film, and the second wall film has a first Two retaining wall areas and a second non-retaining wall area, the second retaining wall area is located on the first retaining wall area, and the cross-sectional area of the second retaining wall area is not larger than the first retaining wall area; The first and second non-retaining wall areas are removed by the beam of light, and the first and second retaining wall areas are retained, wherein the first and second retaining wall areas enclose a window that exposes the working surface; wherein the After the first barrier film is formed on the working surface, a laser shielding copper layer that exposes the first non-wall area but covers the first wall area is formed on the first barrier film, and the second barrier film When the wall film is formed on the first wall film, a part of the second wall film covers the laser shielding copper layer. The method for forming an optical barrier by laser opening as claimed in claim 1, wherein the cross-sectional area of the second barrier region is smaller than that of the first barrier region. The method for forming an optical barrier by opening a laser window as described in claim 1 further includes: after the first and second non-blocking wall regions are removed, forming at least one photoelectric barrier on the working surface in the window A unit, the photoelectric unit is one of a light emitting unit and a photosensitive unit. The method for forming an optical barrier by opening a laser window as described in claim 3 further includes: after disposing the at least one photoelectric unit in the window, dispensing glue in the window. The method for forming an optical barrier by laser window opening as described in claim 1, wherein the first barrier film is not fully cured when formed on the working surface, and the second barrier film is formed before the first barrier film , the first wall membrane is fully cured. An optical barrier structure, comprising: a base plate with a working surface; a first barrier layer formed on the working surface, the first barrier layer enclosing a first window, the working surface on the first A window is exposed; a laser shielding copper layer is formed on an upper surface of the first wall layer but not formed on the side walls surrounding the first window; and a laser shielding copper layer is formed on the copper layer The second retaining wall layer encloses a second opening, the cross-sectional area of the second retaining wall layer is smaller than that of the first retaining wall layer, and the profile of the second opening is larger than that of the first retaining wall layer. opening a window, and the second opening exposes a part of the laser shielding copper layer. The optical blocking wall structure as claimed in claim 6 further includes at least one photoelectric unit formed on the working surfaces in the first and second openings.

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