CN1591093A - Optical interference type display panel and manufacturing method thereof - Google Patents

Abstract

The present invention provides an optical interference display panel and a manufacturing method thereof, wherein the optical interference display panel comprises a substrate, an optical interference reflection structure and a non-light-transmitting protective structure. The optical interference reflection structure comprises a plurality of color-changing pixel units formed on the substrate. The non-light-transmitting protective structure is bonded to the substrate using an adhesive material, and the optical interference reflection structure is encapsulated therebetween. The non-light-transmitting protective structure blocks and absorbs light, so that the light cannot be emitted outward through the defects of the optical interference reflection structure. In addition, the non-light-transmitting protective structure and the adhesive material also protect the optical interference reflection structure from being damaged by the external environment.

Description

Optical interference type display panel and manufacturing method thereof

technical field

The invention relates to a flat display and a manufacturing method thereof, in particular to an optical interference type display panel and a manufacturing method thereof.

Background technique

Due to the characteristics of small size and light weight, the flat panel display has great advantages in the portable display device and the display market for small space applications. In addition to liquid crystal displays (Liquid Crystal Display, LCD), organic electro-luminescent displays (Organic Electro-Luminescent Display, OLED) and plasma flat panel displays (Plasma Display Panel, PDP), etc. A flat display mode has been proposed.

This kind of display formed by light interference type variable color pixel unit array is characterized by low power consumption, fast response (Response Time) and bi-stable (Bi-Stable) characteristics in essence, and will be applicable to display Panel, especially in the application of portable products, such as mobile phone (Mobile Phone), personal digital assistant (PDA), portable computer (Portable Computer) and so on.

Please refer to US Patent No. 5,835,255, which discloses an Array of Modulation for visible light, which is a color-variable pixel unit, and is used as a flat-panel display. Please refer to FIG. 1A , which is a schematic cross-sectional view of a color-changing pixel unit in the prior art. Each color-variable pixel unit 100 is formed on a substrate 110 and includes two walls 102 and 104 , and a cavity 108 is formed between the two walls 102 and 104 supported by a support 106 . The distance between the two walls 102, 104, ie the width of the chamber 108 is D. The wall 102 is a light incident electrode, which has light absorption rate and can absorb part of visible light. The wall 104 is a light reflective electrode, which can be deformed by voltage driving.

Generally, white light is used as the incident light source of the color-changing pixel unit 100 , and the white light is composed of light rays of different wavelengths (Wave Length, represented by λ) in the visible light spectrum range. When the incident light passes through the wall 102 and enters the chamber 108, only the incident light meeting the wavelength limit in formula 1.1 will produce constructive interference in the cavity 108 and be reflected and output, where N is a natural number. in other words,

2D=Nλ ₁ (1.1)

When the double length 2D of the chamber 108 satisfies an integer multiple of the incident light wavelength _λ1 , the incident light wavelength _λ1 can be made to produce constructive interference in the chamber 108, and the reflected light of the wavelength _λ1 is output. At this time, the observer's eyes observe along the direction of the incident light incident wall 102, and can see the reflected light with a wavelength of _λ1 . Therefore, the color-changing pixel unit 100 is in an "on" state, that is, it is bright. status.

FIG. 1B is a schematic cross-sectional view of the color-changing pixel unit 100 in FIG. 1A after voltage is applied. Please refer to FIG. 1B , driven by the voltage, the wall 104 will deform due to the electrostatic attraction, and collapse toward the wall 102 . At this time, the distance between the two walls 102, 104, that is, the length of the chamber 108 is not zero, but d, and this d can be equal to zero.

That is to say, D in the formula 1.1 will be replaced by d, among all the wavelengths of the light in the incident light, only the wavelength (λ ₂ ) conforming to the formula 1.1 can produce constructive interference in the cavity 108, through the reflection of the wall 104 output through the wall 102 . In this color-changing pixel unit 100, the wall 102 is designed to have a higher light absorption rate for light with a wavelength of _λ2 , so all light rays in the incident light are filtered out, and the wall 102 along the incident light An observer looking in that direction will not see any light being reflected. Therefore, at this time, the color-changing pixel unit 100 is in an “off” state, that is, a dark state.

As mentioned above, driven by the voltage, the wall 104 will deform due to the electrostatic attraction, and collapse toward the wall 102, so that the color-changing pixel unit 100 switches from the "on" state to the "off" state. And when the color-changing pixel unit 100 is to be switched from the "off" state to the "on" state, the voltage used to drive the deformation of the wall 104 must be removed first, and then rely on its own deformation recovery force to lose the electrostatic attraction The force acting wall 104 will return to the original state as shown in FIG. 1A , so that the color-changing pixel unit 100 presents an "on" state.

However, the above-mentioned light reflective electrode (wall 104) is a thin film layer (Membrane), and its material is generally metal material, and is usually manufactured by sacrificial layer technology in Micro Electro Mechanical System (MEMS). The thickness of the light reflective electrode is very thin, if there is a mistake in the manufacturing process, or if it is touched by a little external force, it may be damaged.

For example, when the photo-reflective electrode is touched during the manufacturing process or during the handling process, holes may be formed in the light-reflective electrode, and the color-changing pixel unit with the hole cannot reflect at the position of the hole. Rays of incoming light. Moreover, the user can see things behind the light interference display panel through the hole, such as the circuit board in the display, and even other light sources. When the color-changing pixel unit with the hole is operated in the dark state, the light from other light sources behind it may pass through the hole, so that the color-changing pixel unit shows a bright state instead. Even, the light from the original incident light source may be reflected by the things behind the light interference display panel after passing through the hole, and the reflected light is directly reflected without being screened by the color-changing pixel unit , which also causes a bright state.

The contrast of a display panel is generally defined as the ratio of the brightness of the bright state to the brightness of the dark state when it operates. Since the entire interferometric display panel is composed of several color-variable pixel units, these color-variable pixel units with holes causing bright spot defects will reduce the contrast of the display panel and degrade the display quality of the display panel.

Contents of the invention

The purpose of the present invention is to provide an optical interference type display panel and its manufacturing method, which are used to improve the problem of hole defects in the optical interference type reflective structure.

Another object of the present invention is to provide an optical interference display panel and a manufacturing method thereof for improving the contrast of the optical interference display panel.

Another object of the present invention is to provide a light interference type display panel and a manufacturing method thereof, which are used to protect the light interference type reflective structure therein from being damaged by the external environment.

Another object of the present invention is to provide an optical interference display panel and its manufacturing method, which are used to improve the display quality, reliability and service life of the optical interference display panel.

In order to achieve the above object, the present invention provides an optical interference display panel and a manufacturing method thereof. The optical interference display panel includes a substrate, an optical interference reflective structure and a non-transmissive protective structure. The light interference reflective structure includes several color-variable pixel units and is formed on the substrate. The non-light-transmitting protection structure is bonded to the substrate by an adhesive material, and the light interference reflective structure is wrapped between the two. The non-light-transmitting protective structure blocks and absorbs the light, so that the light cannot go out through the defect of the light interference reflective structure. In addition, the non-light-transmitting protective structure and the adhesive material also protect the light interference reflective structure from being damaged by the external environment.

According to a preferred embodiment of the present invention, the material of the plate protection structure is a non-transparent material or a light-absorbing material, such as a metal material or a non-transparent polymer material. The non-light-transmitting polymer material can be a polymer material added with dye, such as plastic added with black dye.

The light interference reflective structure includes several color-changing pixel units. The adhesive material seals the periphery of the bonding surface of the non-light-transmitting protective structure and the substrate. The appearance of the non-light-transmitting protective structure is a flat plate structure. The adhesive material is ultraviolet glue, thermosetting glue or other adhesives. Furthermore, spacers are added to the adhesive material. In another preferred embodiment, the shape of the protective structure can also be a "ㄇ"-shaped structure.

According to another preferred embodiment of the present invention, the non-transparent protective structure is a combination of a substrate and a non-transparent thin film layer, and the non-transparent thin film layer is located on the side of the substrate close to the color-changing pixel unit or on the opposite side side. The material of the non-transparent film layer can be a metal film or a light-absorbing film. The light-absorbing film can be a polymer film or a dye film, and is coated on the substrate. Even, the light-absorbing film can also be a multi-layer film, and the multi-layer film formed by metal, metal oxide or other materials absorbs and blocks light.

In the manufacturing method of the present invention, the first electrode and the sacrificial layer are sequentially formed on a substrate, and then openings are formed in the first electrode and the sacrificial layer to be suitable for forming supports therein. A support is formed in the opening, and then a second electrode is formed on the sacrificial layer and the support. Then remove the sacrificial layer by a structure release etching process (ReleaseEtch Process) to form a chamber. Next, the non-light-transmitting protection structure and the substrate are bonded together by an adhesive material, and a pressing process may be applied during the bonding to make the non-light-transmission protection structure and the substrate more tightly bonded. In addition, if a thermosetting adhesive is used as the adhesive material, a heating process can be added so that the thermosetting adhesive can be heated and fixed.

The light interference type display panel of the present invention provides a non-light-transmitting protective structure bonded to the substrate, and covers the light interference type reflection structure in it, so as to prevent light from being emitted outward through the defect of the light interference type reflection structure, causing light interference The problem of the bright spot defect of the type display panel. Therefore, the present invention solves the problem of the bright spot defect, so as to improve the contrast performance of the light interference display panel.

Furthermore, the non-light-transmitting protective structure can prevent the light interference reflective structure from being directly touched by external force, and the light interference reflective structure is sealed by the adhesive material used for bonding, which can effectively avoid the influence of the external environment. For example, water molecules, dust or oxygen in the air will generate electrostatic attraction or oxidize its metal film when it comes into contact with the light interference reflective structure, thereby destroying its optical or electrical properties. Therefore, the present invention can improve the display quality of the optical interference display panel, reduce the occurrence rate of defects, and prolong its service life.

Description of drawings

The technical solutions and other beneficial effects of the present invention will be apparent through the detailed description of specific embodiments of the present invention below in conjunction with the accompanying drawings.

In the attached picture,

FIG. 1A is a schematic cross-sectional view of a color-changing pixel unit in the prior art;

FIG. 1B is a schematic cross-sectional view of the color-changing pixel unit 100 in FIG. 1A after voltage is applied;

Figure 2A is a schematic cross-sectional view of a preferred embodiment of the present invention;

Figure 2B is a schematic cross-sectional view of another preferred embodiment of the present invention;

Figure 2C is a schematic cross-sectional view of another preferred embodiment of the present invention; and

3A and 3B show a manufacturing method according to a preferred embodiment of the present invention.

Detailed ways

In order to improve the problem of hole defects in the light interference reflective structure, the present invention proposes a light interference reflective structure.

The light interference type display panel of the present invention comprises a substrate, a light interference type reflection structure and a non-light-transmitting protection structure. The light interference reflective structure includes several color-variable pixel units and is formed on the substrate. The non-light-transmitting protection structure is bonded to the substrate by an adhesive material, and the light interference reflective structure is wrapped between the two. The non-light-transmitting protective structure blocks and absorbs the light, so that the light cannot go out through the defect of the light interference reflective structure. In addition, the non-light-transmitting protective structure and the adhesive material also protect the light interference reflective structure from being damaged by the external environment.

FIG. 2A is a schematic cross-sectional view of a preferred embodiment of the present invention. The optical interference reflective structure is composed of several color-variable pixel units. For the convenience of illustration, only one variable pixel unit 100 is used to represent the optical interference reflective structure in the optical interferometric display panel of the present invention in the illustrations and figures. As shown in FIG. 2A , a flat panel protection structure 200 a is bonded to a substrate 110 by an adhesive material 202 , wherein the substrate 110 is, for example, a glass substrate or a pair of visible light transparent substrates. In this way, the plate protection structure 200a can reduce the chance of external force touching the color-changing pixel unit 100 .

Furthermore, in this embodiment, the adhesive material 202 seals the periphery of the bonding surface between the plate protection structure 200a and the substrate 110, so that the color-changing pixel unit 100 is isolated from the external environment, so as to avoid the intrusion of water molecules, dust or oxygen in the air And the color variable pixel unit 100 is damaged.

As mentioned above, if the water molecules in the air enter the chamber 108 of the color-changing pixel unit 100, since the distance D of the chamber 108 is quite small, the electrostatic attraction force of the water molecules will be relatively large, resulting in the color-changing pixel unit 100 The problem that the switch cannot be switched smoothly. If oxygen contacts the metal film in the color-changing pixel unit, such as the light incident electrode and the light-reflecting electrode, because the metal film is very easy to oxidize, oxygen will oxidize the metal film, thereby destroying the optical and electrical properties of the color-changing pixel unit 100 .

The adhesive material in the present invention can isolate the color-changing pixel unit from the outside when bonding the protective structure and the substrate. The higher the degree of isolation, the better the effect of preventing the color-changing pixel unit from being damaged by the outside. According to a preferred embodiment of the present invention, when the adhesive material bonds the protection structure and the substrate in a sealed manner to completely seal the color-changing pixel unit therein, the reliability and service life of the color-changing pixel unit can be greatly improved. improve.

In this embodiment, the material of the plate protection structure 200a is a non-transparent material or a light-absorbing material, such as a metal material or a non-transparent polymer material. The non-light-transmitting polymer material can be a polymer material added with dye, such as plastic added with black dye.

Furthermore, the adhesive material 202 uses ultraviolet glue or thermosetting glue. However, other adhesive materials suitable for bonding the flat plate protection structure 200a and the substrate 110 can also be used in the present invention, and are not limited by this embodiment.

It should be noted that, when the tablet protection structure 200 a is bonded to the substrate 110 , a pressing process is usually performed, and a force is applied to make the tablet protection structure 200 a and the substrate 110 more tightly bonded together. In order to prevent the plate protection structure 200a from crushing the wall 104 of the color-changing pixel unit 100 during lamination, or to prevent the protection structure from being displaced or tilted toward the substrate by an external force later, the present invention can be used on the adhesive material 202 Add a spacer to it.

The adhesive material 202 with spacers can not only prevent the panel protection structure 200 a from crushing the color-changing pixel unit 100 during pressing, but also maintain a fixed distance between the panel protection structure 200 a and the substrate 110 . In this preferred embodiment, the size of the spacer is about 100 μm, while the size of the color-changing pixel unit 100 is usually less than 1 μm, so the plate protection structure 200a is separated from the wall 104 by a considerable distance, and the above-mentioned pressure will not occur. bad question.

FIG. 2B is a schematic cross-sectional view of another preferred embodiment of the present invention. The plate protection structure 200 b is a combination of a substrate 212 and a non-transparent film layer 214 , and the non-transparent film layer 214 is located on the side of the substrate 212 close to the color-changing pixel unit 100 or the opposite side thereof.

According to a preferred embodiment of the present invention, the non-transparent film layer 214 is located on the side of the substrate 212 adjacent to the color-changing pixel unit 100, so that the non-transparent film layer 214 can not only block the incident light from the side of the substrate 212, Avoid light penetrating the defects of the color-changing pixel unit 100 to cause bright spot defects, and also directly absorb or not reflect the light incident from the defects of the color-changing pixel unit 100 , avoiding the light being reflected by the substrate 212 to generate bright spot defects.

The material of the non-transparent film layer can be a metal film or a light-absorbing film. The light-absorbing film can be a polymer film or a dye film, and is coated on the substrate. Even, the light-absorbing film can also be a multi-layer film, and the multi-layer film formed by metal, metal oxide or other materials absorbs and blocks light.

FIG. 2C is a schematic cross-sectional view of another preferred embodiment of the present invention. In this embodiment, the protective structure provided by the present invention is a "ㄇ"-shaped protective structure 200c, and the "ㄇ"-shaped protective structure 200c is a flat plate structure with extended side walls. Similarly, the "ㄇ"-shaped protective structure 200c is bonded to the substrate 110 by the adhesive material 202, which not only reduces the chance of external force touching the color-changing pixel unit 100, but also prevents the intrusion of water molecules, dust or oxygen in the air. And the color variable pixel unit 100 is damaged.

The material of the "ㄇ"-shaped protective structure 200c is also a non-transparent material or a light-absorbing material, or a combination of a "ㄇ"-shaped substrate and a non-transparent film layer. In this way, the "ㄇ"-shaped protective structure 200c can not only block the incidence of external light, so as to avoid the defects of bright spots caused by light penetrating through the defect of the color-changing pixel unit, but also directly absorb or not reflect the light incident from the defect of the color-changing pixel unit. light, to avoid the light being reflected by the substrate to produce bright spot defects.

In addition, as shown in the embodiment of FIG. 2A and FIG. 2B , a combination of a "ㄇ"-shaped substrate and a non-transparent film layer can also be provided to achieve the effect and function of the "ㄇ"-shaped protective structure 200c.

3A to 3B show the manufacturing method of the preferred embodiment of FIG. 2A. As mentioned above, for the sake of convenience, only one variable pixel unit is used to represent the optical interference reflective structure in the explanation and the figure. Referring to FIG. 3A , an electrode 310 and a sacrificial layer 311 are sequentially formed on a substrate 309 , and then an opening 312 is formed in the electrode 310 and the sacrificial layer 311 to be suitable for forming a support 306 therein. Next, a support 306 is formed in the opening 312 , and then an electrode 314 is formed on the sacrificial layer 311 and the support 306 .

Please refer to FIG. 3B, remove the sacrificial layer 311 shown in FIG. 3A by a structure release etching process (Release Etch Process) to form a cavity 316 (position of the sacrificial layer 311), the length D of the cavity 316 is the sacrificial layer 311 thickness of. Next, the non-transparent flat plate protection structure 304 is bonded to the substrate 309 with the adhesive material 308 , and a pressing process may be performed during bonding to make the non-transparent flat plate protection structure 304 and the substrate 309 more closely bonded. In addition, if thermosetting glue is used as the adhesive material 308 , a heating process can be added so that the thermosetting glue can be fixed by heat.

The above description explains the manufacturing method of the optical interference display panel with the flat protective structure, and the manufacturing method of the optical interference display panel with the "ㄇ" font protective structure in Fig. 2C is also the same as that shown in Fig. 3A and Fig. 3B The manufacturing method shown is quite similar, so it is only briefly described below.

First, a light interference reflective structure is formed on a substrate, including a first electrode, a second electrode and a support between the two electrodes. Then, the “ㄇ”-shaped protective structure and the substrate are bonded together with an adhesive material. Similarly, when bonding, a pressing process can be applied to make the "ㄇ"-shaped protective structure and the substrate more tightly bonded. In this way, the optical interference display panel with the "ㄇ"-shaped protective structure in FIG. 2C can be manufactured.

The light interference type display panel of the present invention provides a non-light-transmitting protective structure bonded to the substrate, and covers the light interference type reflection structure in it, so as to prevent light from being emitted outward through the defect of the light interference type reflection structure, causing light interference The problem of the bright spot defect of the type display panel. Therefore, the present invention improves the problem of the bright spot defect and improves the contrast performance of the light interference display panel.

Furthermore, the non-light-transmitting protective structure can prevent the light interference reflective structure from being damaged by direct contact with external force, and the light interference reflective structure is sealed by the adhesive material used for bonding, which can effectively prevent the external environment, such as air The water molecules, dust or oxygen in the glass will generate electrostatic attraction or oxidize its metal film when it comes into contact with the light interference reflective structure, thus destroying its optical or electrical properties. Therefore, the present invention can improve the display quality of the optical interference display panel, reduce the occurrence rate of defects, and prolong its service life.

As mentioned above, for those of ordinary skill in the art, other various corresponding changes and modifications can be made according to the technical scheme and technical concept of the present invention, and all these changes and modifications should belong to the appended claims of the present invention scope of protection.

Claims (21)

1, a kind of light interference type display panel is characterized in that, comprises at least:

One first substrate;

One non-printing opacity protection structure utilizes an adhesion material and this first substrate to bind; And

One light interference reflection structure is between this first substrate and this protection structure;

Wherein this non-printing opacity protection structure produces fleck defect in order to prevent this light interference reflection structure of light penetration.

2, light interference type display panel according to claim 1 is characterized in that, this light interference reflection structure comprises at least:

One first electrode;

One second electrode becomes to be arranged in parallel with this first electrode approximately; And

One stilt forms a chamber between this first electrode and this second electrode.

3, light interference type display panel according to claim 1 is characterized in that, this non-printing opacity protection structure is a slab construction or " ㄇ " font structure.

4, light interference type display panel according to claim 1 is characterized in that, the material of this non-printing opacity protection structure is a non-light transmissive material or a light absorbent.

5, light interference type display panel according to claim 1 is characterized in that, this non-printing opacity protection structure comprises at least:

One second substrate; And

One non-light transmission film layer is positioned on this second substrate.

6, light interference type display panel according to claim 5 is characterized in that, this non-light transmission film layer is between this second substrate and this light interference reflection structure.

7, light interference type display panel according to claim 5 is characterized in that, this non-light transmission film layer is a metallic film or an extinction film.

8, light interference type display panel according to claim 1 is characterized in that, this first substrate and this protection sealing structure bind, and are subjected to the destruction of external environment to prevent this interference of light reflection configuration.

9, light interference type display panel according to claim 1; it is characterized in that; the material of this adhesion material comprises a separation material, utilizes this separation material to make and keeps a preset distance between this protection structure and this first substrate, to avoid this this interference of light reflection configuration of protection structure contact injury.

10, light interference type display panel according to claim 1 is characterized in that, the material of this adhesion material comprises a UV glue or a hot-setting adhesive.

11, a kind of manufacture method of light interference type display panel comprises following steps at least:

One first substrate is provided;

Form a light interference reflection structure on this first substrate; And

Utilize a non-printing opacity protection structure and this first substrate to bind, make this interference of light reflection configuration between this non-printing opacity protection structure and this first substrate;

Wherein this non-printing opacity protection structure produces fleck defect in order to prevent this light interference reflection structure of light penetration.

12, manufacture method according to claim 11 is characterized in that, this step that forms this light interference reflection structure comprises at least:

Form one first electrode on this first substrate;

Form a sacrifice layer on this first electrode;

Forming several first is opened within this sacrifice layer and this first electrode;

Form a stilt in each among these first openings;

Form one second electrode on this sacrifice layer and these stilts; And

Remove this sacrifice layer with a structure release etch processing procedure etching.

13, manufacture method according to claim 11 is characterized in that, this non-printing opacity protection structure is a slab construction or " ㄇ " font structure.

14, manufacture method according to claim 11 is characterized in that, the material of this non-printing opacity protection structure is a non-light transmissive material or a light absorbent.

15, manufacture method according to claim 11 is characterized in that, this non-printing opacity protection structure comprises at least:

One second substrate; And

One non-light transmission film layer is positioned on this second substrate.

16, manufacture method according to claim 15 is characterized in that, this non-light transmission film layer is between this second substrate and this light interference reflection structure.

17, manufacture method according to claim 15 is characterized in that, this non-light transmission film layer is a metallic film or an extinction film.

18, manufacture method according to claim 11 is characterized in that, this first substrate and this protection sealing structure bind, and are subjected to the destruction of external environment to prevent this interference of light reflection configuration.

19, manufacture method according to claim 11 is characterized in that, the step of this bonding comprises utilizes an adhesion material to bind this protection structure and this first substrate.

20, manufacture method according to claim 19; it is characterized in that; the material of this adhesion material comprises a separation material, utilizes this separation material to make and keeps a preset distance between this protection structure and this first substrate, to avoid this this interference of light reflection configuration of protection structure contact injury.

21, manufacture method according to claim 19 is characterized in that, the material of this adhesion material comprises a UV glue or a hot-setting adhesive.

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