JP2020019657A - Production method of unit for light control panel, and light control panel - Google Patents

Abstract

To provide a production method of a unit for a light control panel comprising a plurality of individual transparent device substrate pieces cut from a large-sized transparent glass substrate with reflection films formed on both surfaces thereof with high precision, which are firmly laminated with high precision.SOLUTION: A metal reflection film or the like is film-formed on an entire surface of one side of a glass substrate. After the metal reflection film has been removed along cut lines of contours of individual device substrate pieces, a slight adhesive sheet is stuck the entire metal reflection film or the like formed on the opposite surface. A glass surface is split along the cut lines. After the individual device substrate pieces have been separated from the slight adhesive sheet, the individual device substrate pieces are joined by an organic adhesive or by metal bonding between metal layers of the uppermost layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method of manufacturing a device device substrate having a reflective film with high productivity, and more particularly to a method of firmly joining a plurality of the device devices, particularly to an optical device for forming a three-dimensional image in the air. The present invention relates to a method for manufacturing a light control panel unit to be used, and a light control panel using the unit.

A method has been proposed in which optical information from a display or the like is imaged in the air by passing through a light control panel, instead of a general direct-view type display that directly recognizes moving images and still images (see Patent Document 1). . The light control panel has a unit in which a reflective film is formed at regular intervals in a transparent substrate, and has a structure in which two units are orthogonal to each other. The detailed principle is described in patent documents and the like.

As a method of manufacturing the unit, a plurality of transparent synthetic resin substrates or glass plates having a constant thickness with a metal reflecting surface formed on one side are arranged via a transparent adhesive layer so that the metal reflecting surface is arranged in one direction. It is described that the method includes a step of forming a laminate by stacking a plurality of sheets and a step of cutting the laminate so that a cut surface perpendicular to the metal reflection surface is formed.
As another method, a method of manufacturing a unit using total reflection due to a difference in refractive index between a transparent substrate and an air layer without using an adhesive between the transparent substrates has been proposed (Patent Document 2).

JP 2015-172782 JP 2017-53922

Patent Document 1 discloses a method in which the entire sheet having a reflective layer is bonded and laminated, and cut out at a required dimension perpendicularly to the reflective surface. A large amount of labor is required for stable production. For example, when a glass substrate is used as a transparent substrate, it is necessary to have an adhesive strength that can withstand stress generated by cutting the glass, heat and cooling water. Further, in the case of a transparent resin substrate, it can be cut more easily than a glass substrate, but there are problems with the durability of the reflection surface and the flatness of the surface due to the moisture expansion and thermal expansion of the resin.

  In Patent Document 2, input image information is transmitted using total reflection due to a difference in refractive index between an air layer and a glass layer without bonding individual device substrates. The full firing angle is about 41 degrees, and it is not reflected at any higher angle. In addition, when a reflective film is formed on one surface, or when there is no reflective film, the glass surfaces may be joined together without an adhesive, and it is difficult to obtain a stable reflective surface.

  One of the important characteristics in the light control panel is transmission of image information without distortion or the like. Therefore, there should be no foreign matter such as dust or bubbles on the reflection surface of the unit. However, when a device having no reflective film on both sides or one side is used, there is a high possibility that dirt may enter or bubbles may remain. In the unit manufacturing methods disclosed in Patent Documents 1 and 2, there is basically no correction method even if the presence of foreign matter is known after completion, and extremely clean such that there is no optical foreign matter such as dust between individual device substrates during manufacturing. High cleanliness is required for the manufacturing environment and materials used. These cause a large cost increase.

The present invention has been made in view of such circumstances, and has a basic structure in which reflective films are formed on both surfaces of a substrate. In order to minimize foreign matter on the reflective surface, a reflective film is formed on both sides of a large-sized substrate by a vacuum process, and individual device substrates are cut out from the large-sized substrate efficiently. It provides a way to:

In the present invention, reflective films are formed on both surfaces of a transparent glass substrate by a vacuum film forming method such as sputtering. However, it is not easy to cut out an individual device from a glass substrate having a metal film on both sides, and the present invention employs a structure in which at least one metal reflection film is removed along a cutting line. That is, after forming a reflective film or the like on one side, the metal such as the reflective film is removed along the cutting line by a photolithographic method or the like. This method includes a photolithographic method, a laser ablation method, a method of mechanically scraping a metal, and the like, and the present invention is not limited by the method.
Next, a reflective film is formed on the opposite surface of the large glass substrate having the patterned reflective film and the like by a vacuum film forming method such as sputtering.

  After forming a reflective film on the back surface, individual device substrates are cut out from the large glass substrate by cutting. Examples of a cutting method include a laser ablation method, water jet, and cutting with a wheel-shaped tool, and the present invention is not limited by the method. However, the individual device substrate has a thickness of about 0.5 mm and a width of about 2 mm, and the ease of handling after being cut from a large glass substrate greatly affects productivity.

  In the present invention, a slightly adhesive polymer sheet is attached to the surface of the large glass substrate on which the reflective film is formed over the entire surface. As a cutting method, a kerf (new) is formed by a wheel-shaped tool, and then a bending stress is applied to form a crack to process the individual device substrate. Even in this state, it is fixed with a slightly adhesive sheet, and handling is easy.

  In the present invention, the individual device substrates obtained in this manner are laminated and joined together. However, since the reflection surfaces are formed on both sides of the device substrate, the device substrates have an advantage over foreign substances such as dust. high. In addition, the reflection characteristics can be checked using the individual device substrate alone. Furthermore, by forming a pattern for precision processing by a photolithographic method, fine dimensional processing of an individual device substrate can be easily performed, and post-processing after lamination can be recommended.

  Since the individual device substrate according to the present invention has a reflective film on both surfaces, it can be bonded by a colorless transparent or opaque organic adhesive as a bonding method between the substrates, and furthermore, a metal made of a low melting point metal formed on the reflective film. Joining by bonding is possible.

  As the bonding with the organic adhesive, a UV-curable adhesive, a thermosetting adhesive, and a combination thereof are used. As the material of the adhesive, many materials such as acrylic, epoxy, and silicon can be used. Basically, before lamination, the adhesive is cured by applying UV light or heat after coating on one or both surfaces of the individual device substrate, thereby producing a laminate unit. As a coating method, a precise amount of coating can be performed at high speed by a jet dispenser or the like.

When a B-stage adhesive is used, the adhesive is applied to one side of a large substrate by a method such as screen printing or a jet dispenser, and dried at a predetermined temperature. In this state, the individual device substrate is cut, but the B-stage adhesive has no tackiness at all and is not affected by the cutting process. In this state, by stacking the individual device substrates and heating them under pressure, the curing reaction proceeds from the B stage, and highly reliable bonding between the substrates is completed.

  In order to transmit image information with high accuracy, the parallelism between the individual device substrates as well as the quality of the reflection surface is important. Parallelism is important not only in the height direction (approximately 2 mm) of the individual device substrate but also in the length direction (depending on the image size), and the variation in parallelism between each substrate increases the cumulative value as a whole In some cases.

  In order to realize highly accurate parallelism between the substrates, in the present invention, organic polymer particles, glass fibers, and ceramic particles can be mixed as spacers in the organic adhesive. That is, when pressure is applied during curing of the adhesive, the distance between the substrates becomes constant due to the particles. Particles include organic polymer and silica particles. In the case of organic polymer particles, for example, an accuracy of 5.00 μm ± 0.05 μm can be used, and high parallelism can be realized. Inorganic spacers such as silica and glass fibers have a large Young's modulus and are not deformed by pressure, and the gap size is determined by the larger particle size.

  The particle size used can be less than 1 μm or more than 500 μm. However, when the thickness is thin, the curability, management of fillers and foreign substances, and when the thickness is large, not only the curability but also the curing shrinkage and the aperture ratio deteriorate. In addition, it can be determined according to the type of the organic adhesive used. Generally, it is 1 μm to 20 μm, and preferably about 10 μm. Although the effect can be confirmed from 0.01 wt% with respect to the solid content of the adhesive, the optimum amount including the type of the adhesive can be determined. The specific gravity of the inorganic particles is about 2.5, and that of the organic polymer is about 1.2.

  In the present invention, a transparent adhesive having a high transmittance is used as the organic adhesive and the diameter of the spacer between the individual device substrates is changed so that the organic adhesive can be aligned without lowering the aperture ratio. By changing the pitch, optical interference with the pixel pitch of the display as the image information source can be prevented. Further, the same effect can be obtained even when the spacer diameter is the same and the thickness of the glass light guide is different. The display, which is the image information source, is often configured with a grid of several hundred μm, which may cause optical interference with the grid of the high-definition light control panel. By changing it, optical interference can be prevented.

  It is difficult to uniquely determine the optimal alignment pitch and arrangement. That is, the pitch including the black matrix on the display side is various, and the installation angle and the arrangement pitch of the light control panel to be installed for the matrix can be various combinations. Therefore, the optimum combination is actually performed by cut and try. Also, the light control panel is configured by combining two units, but a panel in which the arrangement pitch in each unit is changed can be used.

Next, a description will be given of the lamination between individual device substrates utilizing the joining of the tin-based metal layers formed on the reflection film according to the fourth to seventh aspects.
In the present invention, a tin-based metal layer, which is a low-melting metal, is formed on a metal reflective film, and the metal is melt-bonded to obtain a light control panel unit in which individual device substrates are metal-bonded. Can be.

  Generally, an aluminum alloy or a silver alloy is used as a metal reflection film, but it is extremely difficult to directly join these metals. In the present invention, a tin-based metal layer having a thickness of 0.5 to 30 μm is formed as an uppermost layer on the metal reflection film to form an individual device substrate, and the tin-based metal surface is reduced to reduce the distance between the individual device substrates. Fusion bonding. As a film forming method, a process such as vacuum film forming method such as sputtering, electroplating, hot-dip plating, printing of cream solder, and reflow melting can be used.

  When the tin-based metal film is melt-bonded, for example, a metal layer such as copper or nickel can be formed between the two metals in order to improve the wettability of the reflection film, the aluminum alloy film, and the tin-based alloy. These metals, for example, an aluminum alloy film, a copper film, and a tin-based alloy can be continuously formed in a vacuum.

  In order to join flat individual device substrates, the thickness of the tin-based alloy film is 0.5 μm or more, preferably 1 μm or more, and it is necessary to use a method other than sputtering, such as electroplating or molten solder using a molten tin bath. It is also possible to use a process in which plating and tin-based solder cream are reflowed after printing, and the present invention is not limited to this method. In addition, the tin-based metal layer can be formed on a large-sized substrate, and the melting process after molten solder plating, tin-based solder cream printing, and application with a jet dispenser is not limited to large-sized substrates. It can also be performed on an individual device substrate.

  Many lead metals include tin alone (melting point: 231 ° C), BiSn42 (Sn42) (melting point: 139 ° C), Sn-3Ag-0.5Cu (melting point: 217 ° C), InSn48 (melting point: 119 ° C). Free solder is provided, and the present invention can be used for joining individual device substrates.

  As one of the actual joining methods, as described in claim 4, the tin-based metal surface is reduced and melted to bond with each other. The tin-based metal surface has an oxide film with a thickness of several nm, and it is necessary to remove this oxide film. In general, a reducing material called flux is used. Since the flux removes these oxide films by a corrosion reaction, it is necessary that there is no residue after the treatment in order to ensure reliability. However, since the bonding between the individual device substrates has a structure in which two surfaces are closed at the time of bonding, the selection of the flux is extremely important.

In the present invention, the use of a conventional flux is not limited, but in view of such a situation, a reduction process using formic acid gas is effective. That is, a vacuum is created with the required number of individual device substrates stacked in the chamber, the temperature is raised to near the melting point of the tin-based metal, and formic acid is introduced into the vacuum chamber using nitrogen as a carrier gas in this state. Formic acid gas also penetrates between individual device substrates and decomposes at about 160 ° C to become active hydrogen and carbon dioxide (CO2). Active hydrogen reduces tin oxide on the tin-based metal surface to form metallic tin (Sn) and water (H2O). In this state, when pressure is applied to the stack of individual device substrates, the molten metals are joined by metal bonding. As a result, formic acid is converted into CO2 and H2O by the thermal decomposition and reduction reactions, and does not remain as a corrosive compound. In addition, since bonding is performed in a vacuum environment, air bubbles are not easily generated, and a highly reliable bonding surface can be realized.

  In the present invention, a low melting point cream solder can be applied on a substrate by printing or dispenser in an appropriate amount and used for bonding. In this case, the parallelism and the gap size between the individual device substrates are determined when the cream solder is melted. Depends on pressure. As described in claim 6, in order to achieve parallelism and gap size, 0.01% by weight or more of glass particles, metal particles, and ceramic particles having a diameter of 1 to 30 μm are contained in the solder cream. it can.

As the particle diameter increases, the gap size between the individual device substrates increases, and the ratio of the glass substrate that transmits image information to the opening area increases. That is, since the aperture ratio is deteriorated, the gap size is preferably as small as possible, and preferably 1 to 10 μm.
When the thickness of the tin-based metal layer can be precisely formed with a thickness of 1 to 10 μm, for example, by electroplating or a vacuum film forming process, no spacer is required.

  According to the present invention, a metal reflective film is formed on both sides of a large-sized substrate, and individual device substrates are cut out, and the parallelism and gap size between the individual device substrates are stacked with high accuracy. This has an extremely great effect in that not only can the mechanical dimensional processing and optical transmission characteristics and the like of the individual device substrate alone be managed, but also the yield can be prevented from deteriorating due to foreign matter during lamination.

  Also, the present invention provides a method of cutting an individual device substrate from a large glass substrate having a metal reflection film formed on both sides, by removing the metal reflection film from one side of the glass substrate, thereby ensuring high dimensional accuracy and cutting (braking). To prevent poor appearance.

  In the present invention, as a bonding method between individual device substrates, not only an organic adhesive but also a tin-based metal is formed on a reflective film, and a process of bonding the tin-based metal by metal bonding is adopted. . As a result, a light control panel unit made of all inorganic materials can be realized, and can be used in a high-temperature and high-humidity environment, such as in a vehicle.

1 shows a method for manufacturing an individual device substrate having reflective films on both surfaces according to an embodiment of the present invention. 4 shows a structure having a tin-based metal on a reflective film according to another embodiment of the present invention. 4 shows an example of lamination bonding using a spacer-mixed adhesive according to an embodiment of the present invention. It is a junction schematic diagram between the individual devices which have a tin metal film on both surfaces in embodiment in this invention. This is a surface analysis of a tin plating film, and shows a change in the spectrum of oxygen atoms. This is a surface analysis of a tin plating film, and shows a change in the spectrum of tin atoms.

  A specific embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a general method of manufacturing an individual device substrate according to the present invention. Fig. 1- (a)
As described above, a reflective metal film 2a is formed on one surface of the glass substrate 1. As the glass substrate 1, various kinds of glasses such as soda glass and borosilicate glass can be used. As the reflection films 2a and 2b, aluminum-based or silver-based, and further, a reflection-enhancing film treatment or the like can be used. Specific examples include aluminum-neodymium alloy (Al-Nd), silver-palladium-copper alloy (Ag-Pd-Cu: APC alloy made of Fluor metal). For transmission of image information, the transmission spectrum is preferably flat in the visible region (380 nm to 780 nm). The film thickness is not limited because it does not require conductivity, but is about 10 nm to 20 nm, and may be more. Although not shown, a transparent film such as a silicon dioxide (SiO2) film may be formed between the reflection films 2a and 2b and the glass substrate 1 in order to secure adhesion to the glass substrate 1. .

FIG. 1- (b) shows that the formed reflection film 2a is removed along the cutting line portion, and further the reflection film 2b is formed on the opposite surface. The removing method may be a photolithographic method or a laser ablation method, or may be mechanically shaved using, for example, a carbide head.
In the present invention, the reflective metal films 2a and 2b are formed on both surfaces of the substrate, and the individual device substrate 10 is cut out. However, if the metal films 2a and 2b are present on both sides, the glass substrate 1 cannot be cut accurately. This is because a strain (new) is mechanically or thermally generated on the surface of the glass substrate 1, and the glass substrate 1 is cut by growing the new.

  Next, a reflective film 2b is formed on the surface opposite to the patterned surface 2a. In a vacuum film forming process such as sputtering, a film is not formed on the surface opposite to the film forming surface, so that there is no need to protect the patterning surface, and the process load is small. When the reflective surface 2a is patterned by mechanical or laser ablation, the reflective surfaces 2a and 2b may be patterned after film formation.

In this state, the slightly adhesive film 3 is bonded to the reflection surface 2b. When performing full cut by laser ablation, the film 3 is unnecessary, but generally, as described above, scribes along the cut line to generate a strain, which is grown to produce an individual device substrate. Braking to 10. Since the individual device substrate 10 has a width of about 2 mm and a thickness of about 0.5 mm, it may become individual at the time of scribing, and the slightly adhesive film 3 avoids complicated situations and improves work productivity. Can be done.
For example, a surface protection film SPV series (manufactured by Nitto Denko) and an ELEP holder series (manufactured by Nitto Denko), which can be easily peeled off by ultraviolet irradiation, can be used. In the present invention, various films can be used. .

Next, as shown in FIG. 1- (d), scribing is performed from the patterned cut line portion. In this step, even if the individual device substrate 10 is partially cut into full pieces, the individual device substrate 10 is held by the slightly adhesive film 3, and as a result, the fixation to the stage surface is also stably held.
After all the scribes are completed, as shown in FIG. 1- (e), the film is set on the breaking stage B with the slightly adhesive film 3 facing upward, and a pressure F is applied from above. The surface of the breaking stage B is a relatively soft rubber-like substance, and the glass substrate 1 is distorted by the pressure F, so that the glass substrate 1 is finally divided into individual pieces. It is held by the adhesive film 3.

Thus, the individual device substrate 10 of the light control panel unit is completed. As described in claims 2 and 3, the individual device substrates 10 can be laminated and joined by the organic adhesive 6. FIG. 2 is a schematic diagram of the cross section. The adhesive 6 includes a spacer 7, whereby the gap distance between the individual device substrates becomes constant, the parallelism between the substrates is stabilized, and the deterioration of the image quality due to the reflection surface can be reduced.

If the light transmittance of the organic adhesive is high and the thickness is large, it is possible to form a high transmittance organic adhesive with the same thickness as the glass light guide 10 and use it as an image transmission body. it can. Also, by changing the thickness by the diameter of the spacer, optical interference due to the same pitch can be prevented. Similarly, by making the spacer diameter the same and changing the thickness of the glass light guide, it is possible to prevent optical interference by changing the alignment pitch.

  FIG. 3 shows an example in which individual device substrates 11 are stacked by metal bonding. For example, copper thin films 3a and 3b are formed on reflective films 2a and 2b, and tin-based metals 4a and 4b are further formed. I do. Alternatively, another metal thin film or the like (not shown) may be formed between the copper thin films 3a and 3b to reinforce the bonding strength. Since the reflective films 2a and 2b do not require conductivity, the film thickness is not limited, and may be about 10 nm to 20 nm or more. The copper thin films 3a, 3b should be thicker, in order to melt the tin-based metal films 4a, 4b formed on the upper part and provide them for bonding, and the thickness should be 100 nm or more, preferably 200 nm or more. It is determined by the method of joining the tin-based metals 4a and 4b.

When joining the individual device substrates 11, the tin-based metal films 4a and 4b need to have a sufficient thickness of 0.5 μm so as not to be affected by flatness such as undulation of the substrate surface. More preferably, it is 1 μm or more.
As described above, processes such as vacuum film formation, electroplating, molten solder plating, and reflow melting after printing of solder cream can be used as the film forming method.

  FIG. 4 is an example in which the individual device substrates 11 having the tin-based metal films 4a and 4b are joined to each other, and the required number of individual device substrates 11 are arranged on a stage S that can be heated. In the case of bonding by formic acid reduction, the entire stage S is set in a vacuum chamber and brought into a vacuum state. For example, the chamber vacuum is set to 20 to 100 Pa, and in this state, formic acid is introduced using nitrogen gas as a carrier gas. At a temperature of about 160 ° C., formic acid is decomposed into CO2 and active hydrogen H, and the active hydrogen reduces tin oxide (SnO2) on the tin film surface to form Sn and H2O. In this state, the tin metal films 4a and 4b are melted at a temperature of 231 ° C. or higher, and are joined by applying a pressure G.

  5 and 6 show the results of X-ray photoelectron spectroscopy analysis of the state of the plated tin surface and its lower part of about 2 nm (ULVAC-PHI, PHI-5000 VersaProbe, acceleration voltage 2 kV, Ar). Fig. 5 shows the change in the spectrum O1s of oxygen atoms, and Fig. 6 shows the change in the spectrum Sn3d of tin atoms. The outermost surface is an oxide film, but the lower part is metal tin without oxygen at all. Understand. Therefore, the surface is reduced to about 2 nm to form metallic tin, and a metal bond can be formed with each other.

  To lower the melting point of tin metal to 231 ° C., a tin alloy with a low melting point can be used. For example, an alloy of 58 parts by weight of bismuth (Bi) and 42 parts by weight of tin (Sn) is called BiSn42 and has a melting point of about 139 ° C. Therefore, bonding can be performed at a process temperature of about 160 ° C., which is the decomposition temperature of formic acid. It is not common to form such a tin alloy in a vacuum film formation, and a cream solder or a hot-dip plating process using a molten solder bath is used.

  For example, SB6-HLGQ-20 (Sn-57Bi-0.4Ag + α) etc. can be used for cream solder based on BiSn42. Apply the appropriate amount to the board surface by silk printing or jet dispenser, and raise the board temperature. At a rate of 2 to 4 ° C / sec and a temperature of 170 to 200 ° C, reflow can be performed to form a tin alloy film. A spacer can be mixed into the cream solder to keep the parallelism and the gap size between the individual device substrates at the time of fusion bonding. The spacer may be made of metal particles, glass, ceramic, or the like, instead of an organic material. For example, in the trial production of the present invention, a silica-based particle, Shinshi Ball SW5.0 μm (manufactured by JGC Catalysts & Chemicals, Inc.) was used.

  The individual device substrates prepared in the preceding section can be stacked and bonded together by formic acid reduction bonding. At this time, since the tin-based metal film formed on the copper film by reflow is easy to form with a thick film, there is a high margin for absorbing variations in flatness of the substrate. Or just The surface of the copper film on one side is also a copper oxide film with a thickness of 2 to 3 nm, and is easily reduced by formic acid like the tin metal surface (data not shown).

  INDUSTRIAL APPLICATION This invention is applicable to the manufacturing method of the unit used for the light control panel used for the optical imaging apparatus which forms an image in the air, etc.

1 Glass substrate 2a ・ 2b Reflective film 3 Slight adhesive sheet 4a ・ 4b Copper thin film 5a ・ 5b Tin-based metal thin film 6 Adhesive 7 Spacer
8 Bonding part 10-piece device board 11-piece device board B Breaking stage D Scribing head F Breaking pressure G Joint pressurization S Heating pressurizing stage

Claims (7)

A metal reflective film is formed on the entire surface of one side of a large glass substrate, the metal reflective film is removed along the external cut line of the individual device substrate, and a slight adhesive sheet is bonded to the entire metal reflective film formed on the opposite surface. I do. After cutting the glass surface along the cut line and separating the individual device substrate from the micro-adhesive sheet, light is used to join the individual devices with an organic adhesive or to join the low melting point alloy layers provided on the top layer. A method of manufacturing a control panel unit, and a light control panel using the same.   Organic polymer particles with a diameter or cross-sectional diameter of 1 to 500 μm, or spacers made of glass fibers or ceramic particles, are cured by ultraviolet curing, thermosetting, B-stage, or a combination of these types of organic adhesive solids 2. The method for producing a light control panel unit according to claim 1, wherein the light control panel contains 0.01 wt% or more, and a light control panel using the same.   By changing the spacer diameter mixed in the organic transparent adhesive that bonds between individual devices between individual device substrates, or by changing the thickness of the glass light guide, the alignment pitch of the substrates is changed, and optical interference occurs. 3. The method for manufacturing a light control panel unit according to claim 2, wherein the image quality is prevented from being degraded by the light control panel, and the light control panel using the same.   A tin-based metal layer with a thickness of 0.5 to 30 μm is formed on the uppermost layer of the metal reflection film formed on the glass substrate surface to create an individual device substrate, and the tin-based metal surface is reduced to reduce the distance between the individual device substrates. 2. The method for manufacturing a light control panel unit according to claim 1, wherein the light control panel is laminated by fusion bonding, and a light control panel using the same.   The upper layer metal on the metal reflection film is a metal that can be metal-bonded with the metal reflection film and the tin-based solder, and an appropriate amount of tin-based solder cream is applied on the metal film, and tin is applied in a state where the individual device substrates are joined. 2. The method of manufacturing a light control panel unit according to claim 1, wherein the solder paste is laminated by melting and joining the solder pastes, and the light control panel using the same. The tin-based alloy solder cream contains 0.01wt% or more of glass, metal, or ceramic spacers dispersed in a diameter of 1 to 30μm to keep the stacking gap of individual device substrates constant, 6. The method for manufacturing a light control panel unit according to claim 5, wherein an alignment pitch between the light control panels is changed, and a light control panel using the same.   In a laminated body in which individual devices are joined with a tin-based metal, image quality degradation due to optical interference is prevented by changing the alignment pitch by changing the thickness of the glass light guide. Item 7. A method for manufacturing a light control panel unit according to any one of Items 4 to 6, and a light control panel using the same.

Images