JP5121559B2 - Semiconductor device, display device, and portable device - Google Patents

Description

  The present invention relates to a semiconductor device having a nonvolatile memory, a display device (liquid crystal display, organic EL display, etc.) and a portable device (notebook personal computer, mobile phone, portable information terminal, etc.) using the same.

  In a display device such as a liquid crystal display or an organic EL display, a thin film transistor (TFT) and a display element are formed on a transparent insulating substrate, and the display element is driven by the TFT. In recent years, attention has been focused on a technique of not only driving a display element with a TFT but also providing the TFT with a function of a nonvolatile memory. With this technology, a TFT for driving a display element and a TFT for a non-volatile memory can be simultaneously formed on an insulating substrate in the same manufacturing process, and the display device can be reduced in size and power consumption can be reduced. It becomes.

  For example, Patent Document 1 discloses a TFT for a nonvolatile memory as shown in FIG. In FIG. 12, a TFT memory 90 includes a polysilicon layer 92 having a source 92a, a channel 92b, and a drain 92c formed on a substrate 91, and a gate oxide film (insulating) formed on the polysilicon layer 92. A plurality of granular silicon particles 94 that capture the charge of carriers are injected into the gate oxide film 93 and are contained therein.

When writing information in the TFT memory 90, an appropriate positive voltage is applied to the control gate 96, and electrons are injected from the channel side into the silicon particle 94 by "Fowler-Nordbeim" tunneling. When erasing the information in the TFT memory 90, an appropriate positive voltage is applied to the drain 92c, contrary to the time of writing.
JP 2002-110829 A

  However, it has been found that the nonvolatile memory TFT of Patent Document 1 cannot withstand application to a display device. Specifically, when used as a display device, illumination such as a backlight is necessary. However, when this illumination light hits silicon particles, the trapped charge is activated and flows out of the silicon particles, so that the stored information is stored. It was found that it cannot function as a nonvolatile memory because it is lost.

  For this reason, experiments were conducted using not only silicon particles but also other charge holding films, and various memory holding films without being restricted by the charge holding film, but the solution of such charge leakage was not achieved.

  In addition, the storage element in which stored information is lost due to the incidence of light is not limited to the TFT, and there are various other types.

  Therefore, the present invention has been made in view of such circumstances, and provides a semiconductor device capable of preventing loss of stored information due to incidence of light.

The semiconductor device of the present invention includes an insulating substrate, a non-volatile memory formed on the insulating substrate, a light-shielding body and an optical sheet provided so as to overlap at least an arrangement area of the information storage holding unit in the non-volatile memory. The optical sheet is provided so as to protrude from the arrangement area of the light shield, and has a luminance increasing characteristic such that the luminance of the emitted light increases when the emission angle with respect to the normal of the optical sheet is within ± 60 degrees. The traveling direction of incident light from the outside is aligned.

  The light blocking body is disposed between the optical sheet and the information storage holding unit. Alternatively, the optical sheet is disposed between the light shield and the information storage holding unit.

  For example, a light-shielding body is overlaid on the surface of the optical sheet.

  In addition, the optical sheet has a condensing function only for light that passes through the optical sheet in one direction, and the light shielding body and the information storage holding unit are arranged on the side where the condensing function of the optical sheet occurs. Has been.

  For example, the optical sheet is a prism sheet in which one surface is a prism surface formed by arranging a large number of microprisms and the other surface is a smooth surface.

  Further, at least one surface of the optical sheet has an adhesive action.

  For example, the optical sheet has a laminated structure in which a plurality of optical sheets are stacked.

  In addition, a backlight module is provided on at least one of the front side and the back side of the insulating substrate, and the light shielding body and the optical sheet are disposed between the insulating substrate and the backlight module.

  The nonvolatile memory is a charge holding type. Alternatively, the information storage holding unit of the nonvolatile memory includes a thin film semiconductor element formed on the insulating substrate as a storage element.

  On the other hand, the display device of the present invention is a display device comprising the semiconductor device of the present invention, wherein a thin film semiconductor element is formed on an insulating substrate of the semiconductor device, and the thin film semiconductor element is stored in the nonvolatile memory of the semiconductor device. The thin film semiconductor element is used for driving the display element.

  For example, the non-volatile memory of the semiconductor device stores a gamma correction value used for controlling the display device or a voltage correction value of the electrode of the counter substrate constituting the display device.

  Moreover, you may provide the said light-shielding body and an optical sheet in the front side and back side of the said insulated substrate, respectively.

  A portable device of the present invention includes the display device of the present invention.

  In such a semiconductor device of the present invention, the light shield and the optical sheet are provided so as to overlap at least the arrangement area of the information storage holding unit in the nonvolatile memory. The light blocking body blocks light from entering the information storage holding unit. Further, the optical sheet covers the light shielding body and aligns the traveling direction of incident light from the outside. With this optical sheet, it goes without saying the traveling direction of light incident in the normal direction of the optical sheet, and the traveling direction of light incident obliquely is aligned so as to approach the normal direction. The incident light whose traveling direction is aligned does not enter the periphery of the light shielding body and is reliably blocked by the light shielding body. For this reason, incident light to the information storage holding unit is reduced, and loss of stored information from the information storage holding unit can be prevented. If the optical sheet is omitted and only the light shielding body is disposed, light that has entered obliquely or light that has sneak into the light can easily enter without avoiding the light shielding body. It is not possible to prevent the loss of stored information from the information storage holding unit.

Further, the optical sheet has a luminance increasing characteristic such that the luminance of the emitted light increases when the emission angle with respect to the normal of the optical sheet is within ± 60 degrees. In this case, most of the incident light of the optical sheet is emitted within an emission angle within ± 60 degrees with respect to the normal of the optical sheet, and the traveling direction of the light transmitted through the optical sheet is aligned well, so that the incident light is made by the light shielding body. The light can be reliably blocked.

  Here, the luminance increase angle means an angle at which the luminance increases in some cases as compared to the case where there is no optical sheet. If the luminance in the normal direction is 1 when there is no optical sheet, it becomes about 1.5 to 2 when the optical sheet is used. As for the relationship between the luminance increase rate and the luminance increase angle, for example, when the luminance in the normal direction is 1.5, the luminance increase angle is in a wide range of about ± 60 degrees, and when there is no optical sheet, Brightness increases. For example, when the luminance in the normal direction is 2, the luminance increase angle is about ± 30 degrees. When the light shield is much larger than the memory holder, or when the distance between the light shield and the memory holder is short, an optical sheet having a wide luminance increase angle of ± 60 degrees can be used. In addition, when the light shield is the same size as the memory holding unit, or when the distance between the light shield and the memory holding unit is long, it is necessary to use an optical sheet having a narrow luminance increase angle of ± 30 degrees.

  In addition, the light blocking body is disposed between the optical sheet and the information storage holding unit. In this case, since the traveling direction of the light incident obliquely or wrapping around by the optical sheet is aligned, the incident light with the aligned traveling direction is incident on the light shielding body. Incident light or sneak-in light is difficult to enter by avoiding the light shield, and the light can be effectively blocked by the light shield.

  Alternatively, the optical sheet is disposed between the light shield and the information storage holding unit. In this case, the light incident obliquely or wrapping around by the light shielding body is not necessarily blocked, and these light can enter the optical sheet while avoiding the light shielding body. However, even if the traveling direction of the light is directed to the information storage holding unit, the optical sheet is changed so that the traveling direction approaches the normal direction of the optical sheet, so that the light enters the information storage holding unit. It becomes difficult to do. Further, in the configuration in which the information storage holding unit of the nonvolatile memory is provided on a transparent insulating substrate in a display device such as a liquid crystal display or an organic EL display, the size of the light shielding body is limited. When the sheets are overlapped, the optical sheet is uneven at the part where the light shielding body is present and the part where the light shielding body is absent, and the effect of aligning the traveling direction of light by the optical sheet is impaired. However, since the size of the optical sheet is not limited, when the optical sheet is overlaid on the insulating substrate and the light shielding body is overlaid on the optical sheet, the optical sheet becomes flat without being uneven. The effect can be kept.

  For example, a light shield is formed on the surface of the optical sheet. In this case, since the light shielding body is integrated with the optical sheet, the number of parts can be reduced, the manufacturing cost can be reduced, and the manufacturing process can be simplified. More specifically, the light shielding body can be formed simply by applying a black paint to the optical sheet, and the light shielding body can be manufactured inexpensively and easily.

  Further, an optical sheet that has a light condensing function only for light transmitted in one direction and does not have a light converging function for light transmitted in the other direction can be used. In this case, the incident light to the information storage holding unit is blocked by disposing the light shielding body and the storage holding unit on the side where the light collecting action of the optical sheet is generated, thereby preventing the loss of the stored information from the information storage holding unit. Can do.

  For example, the optical sheet is a prism sheet in which one surface is a prism surface formed by arranging a large number of microprisms and the other surface is a smooth surface. The optical sheet is obtained by arranging microprisms, microlenses, and the like on a transparent or opaque sheet, for example, and has an advantage of being inexpensive and easy to process. The optical sheet is a general term for sheets having an optical function, such as a diffusion sheet, a reflection sheet, a lens sheet, and a polarizing sheet. Among these, the prism sheet has the highest effect of aligning the traveling direction of light. In this prism sheet, when light in various directions enters the smooth surface, the traveling directions of these lights are aligned on the prism surface, and the light having the aligned traveling directions is emitted from the prism surface. Further, when light having a uniform traveling direction enters the prism surface, the traveling direction of the light is changed or diverged, and the light is emitted from the smooth surface. Therefore, the method of using the optical sheet differs depending on the orientation of the prism surface and the smooth surface.

  Further, since at least one surface of the optical sheet has an adhesive action, the optical sheet can be attached without using an adhesive tape or the like, and the number of parts such as the adhesive tape can be reduced. Further, the optical sheet can be stuck without any gap, and light leakage from the gap can be eliminated.

  For example, when the optical sheet has a laminated structure in which a plurality of optical sheets are stacked, the light traveling direction can be more strictly controlled, and the light shielding effect by the light shielding body can be improved. Further, the light traveling direction may be controlled by overlapping optical sheets of the same type and the same characteristics, or by overlapping optical sheets of different types or characteristics.

  The nonvolatile memory is of a charge holding type, and includes, for example, a thin film semiconductor element as an information storage holding unit on an insulating substrate. Such a charge retention type memory or thin film semiconductor element is difficult to retain stored information in a situation where light is incident, so that it effectively blocks incident light by a combination of a light shielding body and an optical sheet. This makes it practical.

  For example, in the case of including a backlight module provided on at least one of the front side and the back side of the insulating substrate, the light shielding body and the optical sheet are disposed between the insulating substrate and the backlight module. Thereby, the light of the backlight module is blocked by the light shielding body and the optical sheet, and this light does not enter the information storage holding portion of the nonvolatile memory on the insulating substrate. In addition, if the optical sheet is overlaid on the entire area of the backlight module, the direction of the light emitted from the backlight module can be substantially aligned with the normal direction of the optical sheet, and the brightness in this direction can be increased. The power consumption of the module can be reduced.

  On the other hand, in the display device of the present invention, a thin film semiconductor element is formed on the insulating substrate of the semiconductor device of the present invention, the thin film semiconductor element is used as a storage element of an information storage holding portion of a nonvolatile memory of the semiconductor device, and the thin film A semiconductor element is used for driving a display element. Accordingly, a thin film semiconductor element for driving a display element and a thin film semiconductor element for a non-volatile memory can be simultaneously formed on an insulating substrate in the same manufacturing process, and the display device can be reduced in size and power consumption can be reduced. Is possible. In addition, since light incident on the thin film semiconductor element for nonvolatile memory is blocked by the light shield and the optical sheet, it is possible to prevent the outflow of charges from the thin film semiconductor element, that is, loss of stored information. Examples of display devices that require a thin film semiconductor element for driving a display element and a thin film semiconductor element for a nonvolatile memory include a liquid crystal display and an organic EL display.

  For example, a nonvolatile memory of a semiconductor device stores a gamma correction value used for controlling the display device or a voltage correction value of an electrode on the counter substrate that constitutes the display device.

  In addition, when light is incident on the front side and the back side of the insulating substrate, incident light on the front side and the back side can be blocked by providing a light blocking body and an optical sheet on the front side and the back side, respectively.

  Moreover, since the portable apparatus of this invention is equipped with the display apparatus of the said invention, there exists the same effect. Examples of portable devices include notebook computers, cellular phones, and portable information terminals.

  The various configurations of the present invention can be combined with each other.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view schematically showing Embodiment 1 of the semiconductor device of the present invention. The semiconductor device 1 of the present embodiment is assumed to be applied to a display device such as a liquid crystal display or an organic EL display, and is included in the display panel. For this reason, light from inside or outside the display device enters the semiconductor device 1.

  Further, the semiconductor device 1 has a charge retention type nonvolatile memory, and if light enters the nonvolatile memory, the charge of the nonvolatile memory flows out and the stored information is lost.

  For this reason, the semiconductor device 1 has an insulating substrate 2, a nonvolatile memory 4 formed on the insulating substrate 2, and information storage and holding of the nonvolatile memory 4 so that light is not incident on the nonvolatile memory. A lower light-shielding body 5 that covers the lower side of the unit 3, an upper light-shielding body 6 that covers the upper side of the information storage holding unit 3 of the nonvolatile memory 4, and a lower optical sheet 7 that is disposed further below the lower light-shielding body 5. And an upper optical sheet 8 disposed further above the upper light shield 6.

  The nonvolatile memory 4 is sandwiched and covered between the lower light-shielding body 5 and the upper light-shielding body 6, and is also covered with the lower optical sheet 7 and the upper optical sheet 8, and these light-shielding bodies 5 and 6 and the optical The incident light to the information storage holding unit 3 of the nonvolatile memory 4 is effectively blocked by the sheets 7 and 8.

  Next, the insulating substrate 2, the non-volatile memory 4, the light shields 5 and 6, and the optical sheets 7 and 8 will be individually described in detail.

  The insulating substrate 2 is a transparent substrate having insulating properties. The material of the insulating substrate 2 is, for example, a plastic substrate such as a glass substrate, acrylic resin, polycarbonate resin, polysulfone resin, polymethylpentene resin, polyarylate resin, polyimide resin, or phenol resin.

  The transparent substrate is used because the semiconductor device 1 is included in the display panel of the display device, so that light can be transmitted through the insulating substrate 2 and an image can be displayed by the transmitted light. This is to prevent the light from being blocked by the light and the image display from being impaired. For example, in the case of a liquid crystal display, light from the backlight module is transmitted through the insulating substrate 2. In the case of an organic EL display, light from the display element passes through the insulating substrate 2.

  However, since the insulating substrate 2 is transparent, if the non-volatile memory 4 on the insulating substrate 2 is not shielded, light from the display panel itself or external light enters the non-volatile memory 4 and the non-volatile memory The stored information is lost. For this reason, light shielding of the non-volatile memory 4 by the light shielding bodies 5 and 6 and the optical sheets 7 and 8 is required.

  Next, the nonvolatile memory 4 has an information storage holding unit 3. In the nonvolatile memory 4 of FIG. 1, a semiconductor layer 9, an information storage holding unit 3, and a gate electrode 10 are sequentially stacked on an insulating substrate 2. In the semiconductor layer 9, a channel region and a source region and a drain region on both sides thereof are formed, and these regions are disposed immediately below the gate electrode 10. The nonvolatile memory 4 is a charge holding type MONOS type memory, and is composed of three layers in which the information storage holding unit 3 is sandwiched between silicon nitride films.

  In such a nonvolatile memory 4, the stored information is lost due to incident light, so that the light shielding by the light shielding bodies 5 and 6 and the optical sheets 7 and 8 is necessary.

  Note that the nonvolatile memory 4 is not limited to the configuration or type shown in FIG. 1, and is applicable to the present embodiment as long as the stored information is lost due to incident light.

  The nonvolatile memory 4 continuously stores the stored storage information, but the storage time is not clearly defined. For example, it may be considered that the storage information retention time is longer than that of the DRAM, or that the storage information can be retained for a certain time or more. The retention time of stored information depends on the characteristics of the memory, but may be one hour or more or ten years or more. Depending on the purpose of use, the storage information may be held for about one hour or one day, and a refresh operation such as additional writing may be performed as necessary to enable long-term storage.

  For example, as the non-volatile memory 4, in addition to the charge holding type memory, a memory such as FeRAM using a ferroelectric material, a memory such as MRAM using a magnetic material, a memory such as PRAM or RRA using a resistance value, etc. And memory using carbon nanotubes. Regardless of the type of memory, problems such as the loss of stored information due to light irradiation, or the failure of normal reading of stored information due to noise current or the like can occur.

  In particular, the charge retention type memory is likely to cause problems such as loss of stored information due to light irradiation, or failure of normal reading of stored information due to noise current or the like. For this reason, the light shielding by the light shielding bodies 5 and 6 and the optical sheets 7 and 8 is significant. As a charge retention type non-volatile memory, there are EPROM or EEPROM or flash memory with a floating gate as a charge storage layer, MONOS or SONOS with a silicon nitride film as a charge retention film, nanodots that retain charges in particles such as silicon or metal Memory etc. are mentioned.

  FeRAM, PRAM, RRAM, and MRAM generally have a structure in which the gate electrode 10 and the information storage holding unit 3 are spatially separated as shown in FIG. In the nonvolatile memory 4 </ b> A of FIG. 2, the semiconductor layer 9 is formed on the insulating substrate 2, the gate insulating film 11 and the gate electrode 10 are sequentially stacked in one part of the semiconductor layer 9, and in the other part of the semiconductor layer 9. The lower wiring electrode part 12, the information storage holding part 3, and the upper wiring electrode part 13 are sequentially laminated. In the semiconductor layer 9, a gate electrode 10 and source and drain regions on both sides thereof are formed. These regions are arranged immediately below the gate electrode 10, and the source region or the drain region is a lower wiring electrode portion. 12 is connected.

  In such FeRAM, PRAM, RRAM, and MRAM, when the information storage holding unit 3 is irradiated with light, the stored information is lost. Therefore, the information storage holding unit 3 is configured by the light shields 5 and 6 and the optical sheets 7 and 8. It is necessary to shield the light.

  Further, although not shown, an insulating film is preferably formed between the upper light shield 6 and the upper wiring electrode portion 13. By forming the upper wiring electrode portion 13 in this insulating film, the degree of freedom in design increases. Further, if an insulating film is formed also on the upper wiring electrode portion 13, the nonvolatile memory 4 and the like can be protected by this insulating film.

  Next, the lower light-shielding body 5 and the upper light-shielding body 6 cover the upper and lower sides of the information storage holding unit 3, respectively, for example, incident light from outside such as indoor lighting or sunlight, and the back of the display device. Blocks incident light from light modules and display elements. When the nonvolatile memory 4 is incorporated in the display device as a component, the light from the outside and the light from the backlight or the display element are on the upper and lower sides, regardless of whether the nonvolatile memory 4 is mounted face-up or face-down. Since it enters from the side, the light shielding body is provided on both the upper side and the lower side.

  At least one of the lower light-shielding body 5 and the upper light-shielding body 6 has an extension length of the light-shielding body from the information storage holding unit 3 as shown in FIGS. When the distance between them is H, the protrusion length L and the distance H are set so that the protrusion degree defined by L / H is 0.1 or more.

  As a result, the light blocking effect by the light blocking body is significantly improved. The protrusion degree L / H is basically preferably larger and is not limited. For example, the protrusion degree L / H may be set in the range of 0.1 to 10,000. It is preferable to set to 1-100. Further, as shown in the upper side light shield 6 in FIG. 2, the protrusion degree L / H of the light shield may be different between the right side and the left side of the information storage holding unit 3. In this case, the smaller protrusion degree L / H determines the blocking effect of incident light on the information storage holding unit 3.

  In addition, the optical characteristics of the light blocking bodies 5 and 6 are not limited as long as the light shielding bodies 5 and 6 can attenuate the intensity of light applied to the information storage holding unit 3. For example, it is preferable that the average value of the transmittance of light having a wavelength of 300 to 700 nm is 50% or less, and it is more preferable that the average value of the transmittance is smaller. Most preferred is a transmittance of 0.01% or less. This is because more effective light shielding is possible in an environment where strong light is incident.

  Furthermore, although the thickness of the light-shielding bodies 5 and 6 is not specifically limited, It is preferable to set in the range of 3 nm-1 mm. Thereby, an increase in the thickness of the semiconductor device 1 can be suppressed while ensuring a sufficient light shielding property. The thickness of the lower light-shielding body 5 and the upper light-shielding body 6 may be the same as or different from each other.

  The light shielding bodies 5 and 6 are made of, for example, only a light shielding material or a base material containing a light shielding material. The light shielding material is, for example, a black pigment, such as carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, It can be selected from activated carbon, ferrite (nonmagnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, complex oxide black pigment, and anthraquinone organic black pigment.

  The light shielding material may be metal particles or a metal film. The metal particles or metal film includes, for example, periodic table group 1 elements such as lithium, sodium, potassium, rubidium, and cesium; periodic table group 2 elements such as magnesium, calcium, strontium, and barium; scandium, yttrium, and lanthanoid elements (lanthanum, Group 3 elements of the periodic table such as cerium, actinide elements (actinium, etc.); Group 4 elements of the periodic table, such as titanium, zirconium, hafnium; Group 5 elements of the periodic table, such as vanadium, niobium, tantalum; Periodic table group 6 elements; manganese, technetium, rhenium and other periodic table group 7 elements; iron, ruthenium, osmium and other periodic table group 8 elements; cobalt, rhodium, iridium and other periodic table group 9 elements; nickel, palladium, Periodic table group 10 elements such as platinum; circumferences of copper, silver, gold, etc. Group 11 element; Periodic table group 12 element such as zinc, cadmium, mercury; Periodic group 13 element such as aluminum, gallium, indium, thallium; Periodic group 14 element such as tin, lead; Period such as antimony, bismuth, etc. Examples include Group 15 elements. On the other hand, examples of alloys include stainless steel, copper-nickel alloy, brass, nickel-chromium alloy, iron-nickel alloy, zinc-nickel alloy, gold-copper alloy, tin-lead alloy, silver-tin-lead alloy, nickel. -Chrome-iron alloy, copper-manganese-nickel alloy, nickel-manganese-iron alloy, etc.

  The formation method of the light shielding bodies 5 and 6 is not particularly limited, and examples thereof include a method of applying a tape or a sheet (hereinafter referred to as “tape or the like”), a method of applying a paint or resin containing a light shielding material, and the like. The formation methods of the light shielding bodies 5 and 6 may be the same or different from each other. For example, you may form by the method of sticking a tape etc. to one of the light-shielding bodies 5 and 6, and may form the other by another method.

  As described above, there are various materials and manufacturing methods for the light shielding body, but there are no particular limitations on the materials and the manufacturing method, and any material can be used as long as the desired light shielding effect is obtained.

  Next, the lower optical sheet 7 and the upper optical sheet 8 are disposed further outside the lower light shielding body 5 and the upper light shielding body 6. In other words, the lower light shield 5 is disposed between the lower optical sheet 7 and the nonvolatile memory 4, and the upper light shield 6 is disposed between the upper optical sheet 8 and the nonvolatile memory 4.

  The lower optical sheet 7 and the upper optical sheet 8 are, for example, prism sheets having a prism surface and a smooth surface on which a large number of microprisms are arranged, and have a condensing function on the prism surface side, from the smooth surface to the prism surface. Align the traveling direction of the transmitted light. This prism sheet is made of, for example, a polycarbonate film. As shown in FIG. 3, a large number of V-shaped stripe grooves are arranged in parallel on the surface to form a prism surface 20a, and a smooth surface 20b is formed on the back surface. Formed. For example, the angle α of the V-shaped stripe groove is set to 90 °.

  The lower optical sheet 7 is arranged with its prism surface facing the information storage holding unit 3, and when light in a random traveling direction from the backlight module or the display element enters, the traveling direction of this light is aligned. And exit. Since the light whose traveling direction is aligned is effectively blocked by the lower light-shielding body 5, the amount of incident light from the backlight module or display element to the information storage holding unit 3 is significantly reduced. The upper optical sheet 8 is arranged with its prism surface facing the non-volatile memory 4. When incident light in a random traveling direction from indoor lighting or sunlight enters, the traveling direction of this light is changed. Align and emit. The light whose traveling direction is aligned is effectively blocked by the upper light shield 6, so that the amount of light incident on the information storage unit 3 from the indoor lighting or sunlight is significantly reduced. Accordingly, even if light from the outside and light from the backlight or the display element are incident from the upper side and the lower side, the incident light is effectively blocked, and the amount of incident light on the information storage holding unit 3 is significantly reduced. .

  The optical sheets 7 and 8 are not limited to prism sheets, and may be other types of sheets, films, panels, and the like as long as the light traveling direction can be aligned in a predetermined direction. For example, a lenticular sheet in which a large number of semi-cylindrical lenses are formed in parallel, a Fresnel lens sheet that functions as a convex lens or a concave lens, a micro lens sheet in which a large number of micro convex or concave micro lenses are formed on the surface, and a bundle of optical fibers A sheet, a lens or prism attached to the tip of an optical fiber, bundled into a sheet, a polarizer, or the like can be applied. These are formed with irregularities having specific optical characteristics only on one side, but may be formed with irregularities having the same or different optical characteristics on both sides. For example, a two-dimensional prism sheet in which microprisms perpendicular to each other are formed on both sides is preferable as an optical sheet. Further, the light condensing action may be realized as a partially different refractive index distribution while keeping the surface shape flat.

  The optical sheets 7 and 8 have high mechanical strength such as polycarbonate, polyethylene terephthalate, and acrylic resin, have high light transmittance, and are easily molded by compression molding, roll pressing, injection molding, UV curable resin, etc. It can be easily created by transferring. In addition, in the case of a microlens sheet formed with a large number of convex or concave microlenses, it can be formed by printing in addition to these molding methods.

  Moreover, although the optical sheet 7 and 8 is used as a single unit, a plurality of optical sheets may be used in a stacked manner, and a plurality of the same or different types may be used as required. . By stacking a plurality of sheets, it is possible to align in any traveling direction of light.

  Next, the arrangement relationship between the lower light shielding body 5 and the upper light shielding body 6, and the lower optical sheet 7 and the upper optical sheet 8 will be described.

  In FIG. 1, the information storage holding unit 3 of the nonvolatile memory 4 is covered with a lower light shield 5 and an upper light shield 6, and the lower light shield 5 and the upper light shield 6 are further covered with a lower optical sheet 7 and an upper optical sheet. 8 is covered.

  4A and 4B show the positional relationship between the lower light-shielding body 5 and the lower optical sheet 7 in FIG. The lower optical sheet 7 is a prism sheet or the like that aligns the light traveling direction as described above, and the prism surface that produces a light collecting effect while suppressing the divergence angle in the light traveling direction is the information in the nonvolatile memory 4. It is arranged to face the memory holding unit 3. That is, the prism surface of the lower optical sheet 7 having a light condensing function is directed to the information storage holding unit 3. When light in a random traveling direction from the backlight module or the display element is incident on the lower optical sheet 7, the lower optical sheet 7 aligns the traveling direction of the light so as to face the normal direction of the optical sheet 7. For this reason, most of the light emitted from the prism surface of the lower optical sheet 7 is emitted within a certain emission angle ± θ degrees with respect to the normal line of the lower optical sheet 7, and is reliably ensured by the lower light shielding body 5. It is interrupted and no longer enters the periphery of the lower light-shielding body 5 and enters. Thereby, the incident light to the information storage holding unit 3 can be effectively reduced, and loss of stored information from the information storage holding unit 3 can be prevented.

  Similarly, with respect to the upper light shield 6 and the upper optical sheet 8, when incident light from the outside such as a room lamp or sunlight enters, the upper optical sheet 8 causes the incident light to travel in the normal direction of the optical sheet 8. The light is surely blocked by the upper light shield 6.

  If the optical sheets 7 and 8 are omitted and only the light shields 5 and 6 are arranged, the light incident obliquely or the light that has come around enters the light shields 5 and 6 without entering the light shields 5 and 6. It becomes easy, the shielding effect by the light shielding bodies 5 and 6 is lowered, and loss of stored information from the information storage holding unit 3 cannot be prevented.

  The optical sheets 7 and 8 may be other types such as a lenticular sheet and a microlens sheet as described above, but the light collecting effect is suppressed by suppressing the divergence angle in the light traveling direction. It is arranged so that the surface where the error occurs is directed to the memory holding unit 3. Further, a part of the insulating substrate 2 may be made opaque, and this opaque part may be used as the lower light shielding body 5.

  Subsequently, the positional relationship among the lower light shielding body 5, the lower optical sheet 7, and the information storage holding unit 3 will be described in more detail.

  First, as shown in FIG. 5, the distance from the lower light shield 5 to the information storage holding unit 3 is set to H. This distance H corresponds to the thickness of the insulating substrate 2 and the semiconductor layer 9 interposed between the lower light-shielding body 5 and the information storage holding unit 3. Since the insulating substrate 2 and the semiconductor layer 9 are transparent bodies having translucency, it can be said that the thickness of the transparent body is equal to the distance H. Further, since the semiconductor layer 9 is sufficiently thinner than the insulating substrate 2, the thickness H of the transparent body is regarded as the thickness of the insulating substrate 2, and the refractive index of the transparent body (insulating substrate 2) is n.

  Further, the protruding length of the lower light-shielding body 5 from the information storage holding unit 3 is L.

  Furthermore, the luminance increase angle of the lower optical sheet 7 is defined as θ. The luminance increase angle θ is the angle θ in the luminance increase characteristic such that the luminance of the emitted light increases when the emission angle with respect to the normal line of the lower optical sheet 7 is within ± θ degrees.

  When the thickness H and refractive index n of the transparent body, the protruding length L of the lower light-shielding body 5, and the luminance increase angle θ of the lower optical sheet 7 are defined in this way, the following equation (1) derived from Snell's law: ) Is satisfied, most of the light emitted from the prism surface of the lower optical sheet 7 is reliably blocked by the lower light shielding body 5. That is, incident light to the information storage holding unit 3 is effectively blocked by the lower light shielding body 5 and the lower optical sheet 7.

尚、半導体層９が絶縁基板２と比べて十分薄く、透明体の厚みを絶縁基板２の厚みとみなしたが、半導体層９が絶縁基板２と比べて十分厚い場合は、透明体の厚みを半導体層９の厚みとみなし、半導体層９の屈折率をｎとしても良い。

In addition, although the semiconductor layer 9 was sufficiently thin compared to the insulating substrate 2 and the thickness of the transparent body was regarded as the thickness of the insulating substrate 2, when the semiconductor layer 9 was sufficiently thick compared to the insulating substrate 2, the thickness of the transparent body was reduced. The thickness of the semiconductor layer 9 is considered, and the refractive index of the semiconductor layer 9 may be n.

In addition, if there is a plurality of transparent bodies such as the semiconductor layer 9 and the insulating substrate 2 between the information storage holding unit 3 and the lower light-shielding body 5 and there is a plurality of transparent bodies, the refractive index of each transparent body If n ₁ , n ₂ , n ₃ ,..., n _n and the thickness of each transparent body is H ₁ , H ₂ , H ₃ ,..., H _n , the following equation (2) derived from Snell's law is obtained. When it is satisfied, most of the light emitted from the prism surface of the lower optical sheet 7 is reliably blocked by the lower light-shielding body 5.

ここで、先に述べたように情報記憶保持部３からの下側遮光体５のはみ出し長さＬと透明体の厚み（距離）Ｈで表されるはみ出し度Ｌ／Ｈが０．１以上となるように、はみ出し長さＬ及び距離Ｈが設定されると、下側遮光体５による遮光効果が格段に向上する。従って、上記式（１）又は（２）を満たし、かつはみ出し度Ｌ／Ｈを０．１以上に設定することにより、情報記憶保持部３に対する入射光をより確実に遮断することができる。

Here, as described above, the protrusion degree L / H expressed by the protrusion length L of the lower light-shielding body 5 from the information storage holding unit 3 and the thickness (distance) H of the transparent member is 0.1 or more. As described above, when the protrusion length L and the distance H are set, the light shielding effect by the lower light shielding body 5 is remarkably improved. Therefore, by satisfying the above formula (1) or (2) and setting the protrusion degree L / H to 0.1 or more, the incident light to the information storage holding unit 3 can be more reliably blocked.

  Further, as apparent from the above formulas (1) and (2), the brightness increase angle θ of the optical sheet is small, the refractive index n of the transparent body between the light shielding body and the memory holding portion is large, and the thickness H of the transparent body Is thin, the effect of blocking the incident light by the lower light-shielding body 5 and the lower optical sheet 7 can be obtained even if the protruding length L of the lower light-shielding body 5 is short.

  However, the above formulas (1) and (2) are based on the assumption that light passes through the interface of one or more transparent bodies without being reflected once. There is a possibility that this premise is sufficiently satisfied, but even if reflection occurs at the interface of the transparent body, the amount of reflected light is smaller than the amount of transmitted light, so the above formulas (1) and (2) If is satisfied, a light shielding effect is produced. Even if the light-shielding effect is slightly reduced, if the protrusion length L of the lower light-shielding body 5 is increased, the reduction in the effect can be supplemented.

  Of course, the upper light-shielding body 6 and the upper optical sheet 8 also satisfy the above formula (1) or (2) and the protrusion degree L / H is set to 0.1 or more so that the incident on the information storage holding unit 3 is achieved. The light can be blocked more reliably.

  Next, a modification of this embodiment will be described.

  FIG. 4C shows a hybrid sheet 17 </ b> A formed by laminating the lower light-shielding body 5 on the prism surface of the lower optical sheet 7. In such an arrangement, it is not necessary to separately provide a light shield, and the number of parts is reduced. As a result, manufacturing cost can be reduced and manufacturing becomes easy. Further, the hybrid sheet 17A can be manufactured, for example, by simply applying black to the prism surface of the optical sheet, and has advantages such as being inexpensive and easy to process.

  FIG. 4D shows a hybrid sheet 17B in which the lower optical sheet 7 and the lower light shield 5 are integrated. The hybrid sheet 17 </ b> B is obtained by forming a lower light-shielding body 5 by including a light-shielding material in a part of the lower optical sheet 7. Even with such an arrangement, it is not necessary to separately provide a light shielding body, the number of parts is reduced, manufacturing costs can be reduced, and manufacturing processes can be simplified. Further, the hybrid sheet 17B can reduce the thickness of two sheets to one sheet thickness as compared with the configuration in which the optical sheet 7 and the light shielding body 5 are separated from each other. Can be made thinner and thinner.

  In the configurations of FIGS. 4C and 4D, as in the configuration of FIG. 4A, the above formula (1) or (2) is satisfied, and the protrusion degree L / H is 0.1 or more. By setting to, incident light to the information storage holding unit 3 can be blocked more reliably.

  Further, if the optical sheet has a small luminance increase angle θ, a large refractive index n of the transparent body between the light shielding body and the memory holding portion, and a small thickness H of the transparent body, the protrusion length L of the lower light shielding body 5 is reduced. Even if is short, the blocking effect of the incident light by the lower light shielding body 5 and the lower optical sheet 7 can be obtained.

  Of course, the same structure as FIG.4 (b) and FIG.4 (c) is applicable also to the upper side light-shielding body 6 and the upper side optical sheet 8. FIG.

  In FIG. 4E, the information storage holding unit 3, the lower light shielding body 5, and the lower optical sheet 7 are arranged in this order. In other words, the lower optical sheet 7 is disposed between the lower light shield 5 and the information storage holding unit 3. In such an arrangement, light incident obliquely or wraparound light is not blocked by the lower light shielding body 5, and these light can be incident avoiding the lower light shielding body 5. However, even if the traveling direction of the light is directed to the information storage holding unit 3, the traveling direction is changed by the lower optical sheet 7 so that the traveling direction approaches the normal direction of the optical sheet 7. It becomes difficult to enter the memory holding unit 3.

  Here, in order to maintain the optical characteristics of the lower optical sheet 7 with respect to incident light constant, it is necessary to ensure the flatness of the lower optical sheet 7. However, since the light-shielding area by the lower light-shielding body 5 is limited to the part of the information storage / holding unit 3, when the lower optical sheet 7 is overlapped with the lower light-shielding body 5 as shown in FIG. Depending on the presence or absence of the side light shield 5, the lower optical sheet 7 may be uneven, and it becomes difficult to maintain the flatness of the lower optical sheet 7.

  On the other hand, if it arrange | positions as shown in FIG.4 (e), the planarity of the lower side optical sheet 7 is securable irrespective of the presence or absence of the lower side light-shielding body 5. FIG.

  Of course, the same configuration as in FIG. 4D can also be applied to the upper light shield 6 and the upper optical sheet 8.

  FIG. 4F shows a hybrid sheet 17 </ b> C formed by laminating the lower light-shielding body 5 on the smooth surface of the lower optical sheet 7. Even in such an arrangement, as in FIG. 4E, even if the incident light is incident avoiding the lower light shielding body 5, the traveling direction of the incident light is changed by the lower optical sheet 7, Incident light is less likely to enter the information storage holding unit 3. Further, there is no need to provide a separate light shielding body, the number of parts is reduced, manufacturing costs can be reduced, and manufacturing processes can be simplified. Furthermore, the hybrid sheet 17C can be manufactured, for example, by simply applying black to the smooth surface of the optical sheet, and has the advantage of being inexpensive and easy to process.

  By the way, in the arrangement configuration of FIGS. 4A to 4D, it is necessary to arrange the light shields 5 and 6 inside the display panel, and in the arrangement configurations of FIGS. 6 can be arranged outside the display panel.

  For example, in a display device such as a liquid crystal display or an organic EL display, the display elements and drive circuits of the display panel are formed on a transparent substrate. 4A to 4D, the insulating substrate 2 is mounted on the transparent substrate of the display panel, or the transparent substrate is also used as the insulating substrate 2, and the top of the insulating substrate 2 is used. The non-volatile memory 4 is formed, and the light shielding bodies 5 and 6 and the optical sheets 7 and 8 are formed on the lower side and the upper side thereof. In this case, the light shielding bodies 5 and 6 and the optical sheets 7 and 8 can be laminated on a transparent substrate. In such a laminated structure, the light shields 5 and 6 and the optical sheets 7 and 8 can be disposed close to the information storage holding unit 3, so that light can avoid the light shields 5 and 6 and the optical sheets 7 and 8. There is almost no incident around the information storage holding unit 3, and the incident light can be effectively blocked.

  4E and 4F, the light shields 5 and 6 can be arranged and formed outside the transparent substrate of the display panel, and components for fixing the display panel, display device exteriors, and the like can be provided. The light shielding bodies 5 and 6 can be used together, and the manufacturing cost can be reduced.

  Furthermore, the light shielding bodies 5 and 6 may be distributed to both the inside and the outside of the display panel so as to obtain a higher light shielding effect.

  Note that the hybrid sheets in FIGS. 4C, 4D, and 4F include an opaque light shielding member in a part of the optical sheets 7 and 8, respectively. The opaque light shielding body may contain a light shielding material, or the light shielding material may be applied to the optical sheet. The light shielding material is, for example, a black pigment, and the black pigment is, for example, carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, Choose from titanium black, cyanine black, activated carbon, ferrite (nonmagnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, complex oxide black pigment, anthraquinone organic black pigment it can. Alternatively, the light shielding material may be metal particles or a metal film. The metal particles or metal film includes, for example, periodic table group 1 elements such as lithium, sodium, potassium, rubidium, and cesium; periodic table group 2 elements such as magnesium, calcium, strontium, and barium; scandium, yttrium, and lanthanoid elements (lanthanum, Group 3 elements of the periodic table such as cerium, actinide elements (actinium, etc.); Group 4 elements of the periodic table, such as titanium, zirconium, hafnium; Group 5 elements of the periodic table, such as vanadium, niobium, tantalum; Chromium, molybdenum, tungsten, etc. Periodic table group 6 elements; manganese, technetium, rhenium and other periodic table group 7 elements; iron, ruthenium, osmium and other periodic table group 8 elements; cobalt, rhodium, iridium and other periodic table group 9 elements; nickel, palladium, Periodic table group 10 elements such as platinum; circumferences of copper, silver, gold, etc. Group 11 element; Periodic table group 12 element such as zinc, cadmium, mercury; Periodic group 13 element such as aluminum, gallium, indium, thallium; Periodic group 14 element such as tin, lead; Period such as antimony, bismuth, etc. Examples include Group 15 elements. The light shielding material may be an alloy, such as stainless steel, copper-nickel alloy, brass, nickel-chromium alloy, iron-nickel alloy, zinc-nickel alloy, gold-copper alloy, tin-lead alloy, silver-tin-lead alloy. Nickel-chromium-iron alloys, copper-manganese-nickel alloys, nickel-manganese-iron alloys, and the like.

  FIGS. 6A, 6 </ b> B, and 6 </ b> C are a plan view, a back view, and a cross-sectional view illustrating a liquid crystal display to which the semiconductor device of this embodiment is applied. In FIGS. 6A and 6B, the optical sheets 7 and 8 and the backlight module 16 are omitted for convenience of illustration.

  In FIG. 6, the insulating substrate 2 is a transparent substrate, on which another transparent counter substrate 14 is disposed so as to face the liquid crystal layer, the display element, and the display element between the insulating substrate 2 and the transparent counter substrate 14. A drive circuit or the like (not shown) is sandwiched. On the insulating substrate 2, not only the transparent counter substrate 14 but also the nonvolatile memory 4 and the upper light shielding body 6 are provided so as to overlap each other. In addition, a lower light shield 5, a lower optical sheet 7, and a backlight module 16 are sequentially disposed below the insulating substrate 2.

  The non-volatile memory 4 is mounted on the insulating substrate 2 and is disposed near one end of the transparent counter substrate 14 (near the end of the liquid crystal display). The lower light-shielding body 5 and the upper light-shielding body 6 cover the lower side and the upper side of the nonvolatile memory 4, and the lower optical sheet 7 and the upper optical sheet 8 are below and above the lower light-shielding body 5 and the upper light-shielding body 6. Is arranged.

  The nonvolatile memory 4 stores, for example, a gamma correction value used for controlling the liquid crystal display or a voltage correction value of the electrode of the counter substrate 14.

  Next, the insulating substrate 2, the backlight module 16, the transparent counter substrate 14, the light shielding bodies 5 and 6, and the optical sheets 7 and 8 will be described in detail individually.

  TFTs (not shown) for driving display elements are formed in an array on the insulating substrate 2, and a wiring cable (for example, a flexible printed board (for example) for transmitting and receiving pixel display signals to the TFTs. FPC), flexible flat cable (FFC), etc.) 15 are electrically connected. Therefore, not only the nonvolatile memory (a charge holding type MONOS type memory) 4 but also TFTs are formed on the insulating substrate 2. Both are formed using a thin semiconductor layer on the insulating substrate 2. The non-volatile memory 4 is different from the TFT in that it includes the information storage / holding unit 3, but can be simultaneously manufactured in the same manufacturing process as the TFT for driving the liquid crystal display element. Therefore, it is not necessary to add the nonvolatile memory 4 after the TFT is formed on the insulating substrate 2, which facilitates cost reduction and compactness.

  The backlight module 16 is disposed below the insulating substrate 2. The backlight module 16 includes, for example, a light source that emits light (a linear light source such as a cold cathode tube or a point light source such as a light emitting diode (LED)), and a light guide plate that converts the linear light source or the point light source into a surface light source. I have.

  The counter substrate 14 is a substrate for applying a voltage to the entire liquid crystal layer sandwiched between the insulating substrate 2 and the counter substrate 14. In addition, color filters such as RGB may be stacked on the counter substrate 14. Here, the counter substrate 14 is disposed so as to deviate from the upper position of the nonvolatile memory 4.

  In this liquid crystal display, the counter substrate 14 is arranged on the upper side of the insulating substrate 2 and the light of the backlight module 16 is irradiated from the lower side of the insulating substrate 2. It may be arranged so that the light of the backlight module 16 is irradiated from the lower side of the counter substrate 14. Such an arrangement can be freely changed depending on the design, and there is no restriction on which substrate is placed on the upper side. Similarly, the non-volatile memory 4 may be arranged on the lower side of the insulating substrate 2 instead of the upper side, and the vertical direction of the insulating substrate 2 is not limited. For example, the same effect can be obtained even when the upper and lower components of the upper optical sheet 7 are inverted.

  The light shields 5 and 6 are tapes or the like. For example, as shown in FIG. 7 (d), the upper light-shielding body 6 has the first adhesive layer 18b laminated on the lower surface of the black colored layer 18a, or the lower surface of the black colored layer 18a as shown in FIG. 7 (e). Is a single-sided adhesive tape in which a metal layer 18 e and a first adhesive layer 18 b are laminated, and is affixed to the insulating substrate 2 so as to cover the information storage holding unit 3 of the nonvolatile memory 4. At this time, it is preferable that the upper light shield 6 is attached to the non-volatile memory 4 so as to extend from above the wiring cable 15. Thereby, peeling of the wiring cable 15 can be suppressed.

  Even when the upper light-shielding body 6 is formed by applying a paint or resin containing a light-shielding material, the upper light-shielding body 6 is formed to extend from the information storage holding unit 3 of the nonvolatile memory 4 to the wiring cable 15. It is good. Even if it is a film | membrane of the light shielding material formed by application | coating of the coating material or resin, peeling of the wiring cable 15 can be suppressed.

  In addition, when a frame for covering and protecting the formation area of the information storage holding unit 3 is provided on the upper side of the insulating substrate 2, the upper light shielding body 6 of the double-sided adhesive tape is interposed between the frame and the insulating substrate 2. It is preferable to arrange and bond the insulating substrate 2. In this case, the upper light shield 6 plays both roles of adhesion and light shielding. As shown in FIG. 7A, the upper light-shielding body 6 is formed by laminating the first and second adhesive layers 18b and 18c on both surfaces of the black colored layer 18a, or as shown in FIG. 7B, the black colored layer 18a. The white colored layer 18d and the first adhesive layer 18b are laminated on the lower surface of the black colored layer 18a, and the second adhesive layer 18c is laminated on the upper surface of the black colored layer 18a, or the black colored layer 18a as shown in FIG. A double-sided adhesive tape in which a metal layer 18e, a white colored layer 18d, and a first adhesive layer 18b are laminated on the lower surface, and a second adhesive layer 18c is laminated on the upper surface of the black colored layer 18a.

  Moreover, you may apply the double-sided adhesive tape as shown to Fig.7 (a)-(c) to the lower side light-shielding body 5. FIG. By disposing the lower light shielding body 5 between the lower optical sheet 7 and the insulating substrate 2, the lower optical sheet 7 and the insulating substrate 2 can be bonded. In this case, the lower light shielding body 5 plays both roles of adhesion and light shielding.

  In the liquid crystal display shown in FIG. 6, it is particularly necessary to make the thickness of the tape used as the light shields 5 and 6 1 mm or less. In recent years, there has been a high demand for thin and light electronic devices, and the realization of thin and light is progressing. Therefore, it is necessary to form the light shields 5 and 6 as thin as possible. Considering the thickness of electronic parts such as chips and wiring cables, it is preferable that the light shielding bodies 5 and 6 be 1 mm or less. As a result, an increase in the thickness of the display display or the display panel can be suppressed.

  For example, in FIG. 6C, in general, the thickness of the insulating substrate 2 and the counter substrate 14 on which the TFT is formed is about 0.7 mm. In the liquid crystal display, since an optical film (not shown) such as a polarizing film or an optical compensation film is attached to the insulating substrate 2 or the counter substrate 14, the thickness of these substrates becomes about 1 mm, A step of about 1 mm is formed at the end. Since the upper light shield 6 is disposed adjacent to the end of the counter substrate 14, when the thickness of the tape serving as the upper light shield 6 exceeds the height of the counter substrate 14, the upper light shield 6 is larger than the counter substrate 14. Projecting upwards obstructs thinning of the display panel. Further, since it is predicted that the display device will be further thinned in the future, it is desirable that the thickness of the upper light shield 6 is 1 mm or less.

  Further, although the thickness of the substrate including the TFT and the optical film is illustrated, a configuration in which various electronic components are mounted in the area of the nonvolatile memory 4 is also conceivable. When the tape to be the upper light shielding body 6 is bonded not only to the nonvolatile memory 4 but also to such an electronic component, the sum of the thickness of the upper light shielding body 6 and the height of the electronic component makes the height of the counter substrate 14 1 mm. Beyond that, there is a high possibility that the upper light-shielding body 6 protrudes above the counter substrate 14. For this reason, it is necessary to further reduce the thickness of the upper light shield 6 in accordance with the height of the electronic component. For example, if the step of the substrate is 1 mm and the height of the electronic component is 0.9 mm, it is necessary to suppress the thickness of the upper light shield 6 to 0.1 mm or less. Therefore, it is necessary to reduce the thickness of the tape used as the upper light-shielding body 6 in accordance with surrounding mounted components.

  Further, in the configuration in which the electronic component 37 is provided on the insulating substrate 2 as shown in FIG. 8, the upper light shielding body 6 extends from the information storage holding unit 3 of the nonvolatile memory 4 to the electronic component 37. It is preferable. Thereby, the suppression effect of the electrostatic breakdown of the electronic component 37 and the light shielding effect are obtained. The electronic component 37 is, for example, an IC chip, such as a package (for example, a mold package or a ceramic package). When the electronic component 37 is not packaged, the necessity of light shielding the electronic component 37 by the upper light shield 6 is great.

  Next, the lower optical sheet 7 is disposed below the lower light shielding body 5, aligns the traveling direction of light from the backlight module 16, and makes this light incident on the lower light shielding body 5. The upper optical sheet 8 is disposed on the upper side of the upper light shielding body 6, aligns the traveling direction of light from the outside, and makes this light incident on the upper light shielding body 6.

  Specifically, when the light from the backlight module 16 is incident on the lower optical sheet 7 in an oblique direction with respect to the normal line of the lower optical sheet 7, the traveling direction of the light is set to the normal direction. The light is emitted to the lower light shield 5 after being changed so that the light does not enter the nonvolatile memory 4 by going around the periphery of the lower light shield 5. At the same time, the lower optical sheet 7 condenses the light from the backlight module 16 so as to approach the direction of the normal, thereby increasing the luminance in the front direction of the display panel and increasing the display luminance.

  When light from the outside such as an indoor lamp or sunlight enters the upper optical sheet 8 in an oblique direction with respect to the normal line of the upper optical sheet 8, the traveling direction of this light is set to the normal direction. The light is emitted to the lower light shield 5 after being changed so that the light does not enter the nonvolatile memory 4 by going around the periphery of the lower light shield 5. At the same time, the upper optical sheet 8 increases the divergence angle of the light coming from the backlight module 16 via the lower optical sheet 7 to improve the display panel to a wide viewing angle or a specific viewing angle, and the viewing angle dependency. Can be eliminated.

  For example, it is desirable that the thickness of the optical sheets 7 and 8 is 1 mm or less. In recent years, electronic devices have become thinner and lighter, and there is a high demand for electronic components that have been reduced in thickness. For this reason, it is necessary to form the optical sheet as thin as possible. In consideration of the thickness of electronic components such as IC chips and wiring cables in the periphery of the nonvolatile memory, it is preferable that the optical sheet be 1 mm or less, thereby suppressing an increase in the thickness of the entire display device. .

  The optical sheet is not particularly limited as long as it collects light from one side or plays a role of narrowing the light divergence angle. As mentioned above, prism sheet, lenticular sheet, Fresnel lens sheet, micro lens sheet, optical fiber bundled into a sheet form, lens or prism attached to the end of an optical fiber, bundled into a sheet form A polarizer or the like can be applied.

  By selecting the type and usage pattern of these optical sheets, the light divergence angle can be reduced or enlarged in any direction, or reduced or enlarged only in a specific direction. For incident light from the backlight module 16 and the outside, the light traveling direction is aligned by the optical sheet, the light divergence angle is reduced, the light shielding effect by the light shielding body is enhanced, and the information storage holding unit 3 Decreases incident light. Further, for the display light emitted from the surface of the display panel to the outside, the viewing angle is increased by expanding the light divergence angle.

  Further, when a black matrix of display elements is used in the display panel, the light shields 5 and 6 can be formed together with the black matrix, thereby reducing the number of components.

  FIG. 9 is a plan view showing a mobile phone to which the liquid crystal display of FIG. 6 is applied.

  A cellular phone 21 shown in FIG. 9 has a main body housing 22 made of a colored synthetic resin having a wall thickness of 0.3 mm or more, and a liquid crystal display 23 is provided in an opening 22 a of the main body housing 22. In addition, a plurality of operation keys 24 are disposed in the lower part of the main body housing 22. The liquid crystal display panel 23 is configured as shown in FIG. 6, and the upper optical sheet 8 is disposed on the surface thereof. The non-volatile memory 4 is located in the vicinity of the end of the liquid crystal display 23 and is slightly off the opening 22a.

  In the mobile phone 21 having such a configuration, the light of the backlight module 16 is irradiated from the inside of the main body housing 22 to the opening 22a. After the traveling direction of the light is aligned by the lower optical sheet 7, Since this light is incident on the lower light-shielding body 5 (shown in FIG. 6), this light is reliably blocked by the lower light-shielding body 5 and does not enter the nonvolatile memory 4. As a result, loss of stored information from the information storage holding unit 3 of the nonvolatile memory 4 is prevented.

  Further, when the light of the backlight module 16 (shown in FIG. 6) passes through the upper optical sheet 8, the divergence angle is increased. Thereby, the viewing angle of the display panel is improved and widened.

  The semiconductor device of this embodiment or the liquid crystal display of FIG. 6 is not only a mobile phone, but also a terminal information device such as a PDA, a display device such as a personal computer monitor or a liquid crystal television, a monitor such as a car stereo or a car navigation system. Etc. can be applied.

  Next, since the verification experiment of the effect was performed about the semiconductor device of this embodiment, the result is demonstrated.

  Here, an experiment for demonstrating the effect of providing the lower optical sheet 7 and the effect of setting the luminance increase angle θ of the lower optical sheet 7 within 60 degrees will be described.

  In an experiment for examining the effect of providing the lower optical sheet, a semiconductor device 1B as shown in FIG. 10 was used. The nonvolatile memory 4B of the semiconductor device 1B is a nonvolatile memory having a MONOS structure. The transmittance of the lower light-shielding body 5 is 0.01% or less, and the shorter of the protruding length of the lower light-shielding body 5 from the information storage holding unit 3 is L, and the length of L is about 0. 0. 4 mm. Furthermore, since the thickness of the insulating substrate 2 is sufficiently larger than the semiconductor layer 9, the distance H between the lower light-shielding body 5 and the information storage holding unit 3 is set to 0.7 mm. Therefore, L / H = 4/7 = 0.57.

  As the lower optical sheet 7, the prism sheets having the characteristics of the luminance increase angle θ = 60 degrees, 45 degrees, and 25 degrees were exchanged and used.

  A backlight module was disposed below the lower optical sheet 7, and light from the backlight module was irradiated from below the lower optical sheet 7. This backlight module is of a type that uses a light source of an LED, guides the light of the LED by a light guide plate and spreads it in a planar shape, and spreads the spread light in a planar shape with little unevenness by a diffusion sheet. Adjust to light and irradiate this uniform light. Such a backlight module is of a configuration normally used in a liquid crystal display.

  Under such conditions, light of 8000 candela of the backlight module was irradiated from below the lower optical sheet 7, and the threshold change time of the information storage holding unit 3 of the nonvolatile memory 4 was evaluated. The result was as shown in FIG.

  The nonvolatile memory 4 used for the evaluation is a normal MONOS memory, and the storage state is identified by changing the threshold value by applying a voltage. When this memory is exposed to light, the threshold value indicating the storage state changes. The “threshold change time” refers to the amount of time shifted by voltage application as “1”, and when the threshold is lowered by light, the threshold is reduced by 10% with respect to the normalized value “1”. Indicates time. For example, in a P-type memory device, if the threshold value is −1V before voltage application and becomes + 9V after voltage application, the shifted amount is 10V. Since the shifted amount causes a slight error due to the variation in the characteristics of the memory element, the shifted amount is normalized to 1 regardless of whether the shifted amount is 9.5V or 10.5V. The time until the threshold is reduced by 10% with respect to the normalized value “1” as the threshold is lowered by light is the threshold change time.

  Referring to FIG. 11, it can be seen that the threshold change time becomes longer as the luminance increase angle of the lower optical sheet is smaller. This result means that the provision of the lower optical sheet 7 makes it difficult for problems such as loss of stored information to occur.

Further, comparing the state in which the prism sheet having the luminance increase angle of 60 degrees, 45 degrees, and 25 degrees is disposed with the state in which the prism sheet is not disposed, the threshold change time is about 4 × 10 ^{5 in the} state in which the prism sheet is not disposed. It can be seen that the stored information is lost immediately, as short as seconds. On the other hand, when a prism sheet having a luminance increase angle of 60 degrees is arranged, the threshold change time is reliably increased to 6 × 10 ⁵ seconds. Further, as the luminance increase angle is reduced to 45 degrees and 25 degrees, the threshold change time becomes longer as 1.0 × 10 ⁶ seconds and 1.5 × 10 ⁶ seconds, and the stored information is held for a longer time. I understand that. When the ratio of the threshold change time in the state where the prism sheet having the luminance increase angle of 60 degrees, 45 degrees and 25 degrees is arranged to the threshold change time in the state where the prism sheet is not arranged is obtained, 1.5 times. 5 times and 3.7 times.

  From such a demonstration experiment, it can be seen that a sufficient light shielding effect cannot be obtained only by providing the light shielding body, and that the light shielding effect is remarkably improved when the light shielding body and the optical sheet are used in combination. It can also be seen that the effect of the optical sheet can be obtained when the luminance increase angle of the prism sheet is 60 degrees or less. Even in the case of the luminance increase angle of 60 degrees, the threshold change time becomes long, and there is an effect by the optical sheet. Further, when it is necessary to make the threshold change time longer, it is particularly necessary to use a luminance increase angle of 25 degrees. Also, when used in a display device such as a mobile phone, it is necessary to suppress the viewing angle, and since the frequency of use outdoors is high, it is recommended to use 25 degrees with a narrower brightness increase angle because it is often exposed to sunlight. . Also, for example, a large-screen television used indoors is a 25-degree optical sheet with a narrow brightness rise angle that collects light in the normal direction, and then increases the brightness of the light that passes through the memory holding unit. If a 60 degree optical sheet with a wide angle is used, the viewing angle can be widened.

It is sectional drawing which shows roughly Embodiment 1 of the semiconductor device of this invention. It is sectional drawing which shows the modification of the non-volatile memory in FIG. It is sectional drawing which expands and shows an example of the optical sheet in FIG. (A)-(f) is a figure which shows the example of arrangement | positioning of a lower side light-shielding body, a lower side optical sheet, and an information storage holding | maintenance part. It is sectional drawing which expands and shows the lower side optical sheet in FIG. 1, a lower side light-shielding body, and an insulated substrate. (A), (b), and (c) are the top view, back view, and sectional drawing which illustrate the liquid crystal display to which the semiconductor device of FIG. 1 is applied. (A)-(e) is sectional drawing which illustrates a light-shielding body. It is a top view which adds an electronic component to the liquid crystal display of FIG. It is a top view which shows the mobile telephone to which the liquid crystal display of FIG. 6 is applied. It is sectional drawing which shows the structure of the semiconductor device used for verification experiment. It is a graph which shows the result of a demonstration experiment, ie, the relationship between a brightness | luminance rise angle and threshold value change time. It is sectional drawing which shows the structure of the conventional semiconductor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor device 2 Insulating substrate 3 Information storage holding part 4 Non-volatile memory 5 Lower light-shielding body 6 Upper light-shielding body 7 Lower optical sheet 8 Upper optical sheet 9 Semiconductor layer 10 Gate electrode 11 Gate insulating film 12 Lower wiring electrode part 13 Upper wiring electrode portion 14 Counter substrate 15 Wiring cable 16 Backlight module 17A, 17B, 17C Hybrid sheet 18a Black colored layer 18b First adhesive layer 18c Second adhesive layer 18d White colored layer 18e Metal layer 20a Prism surface 20b of prism sheet Smooth surface of sheet 21 Mobile phone 22 Main body casing 23 Liquid crystal display 24 Operation keys

Claims (16)

An insulating substrate;
A non-volatile memory formed on the insulating substrate;
A light-shielding body and an optical sheet provided to overlap at least an arrangement area of the information storage holding unit in the nonvolatile memory,
The optical sheet is provided so as to protrude from the arrangement area of the light shielding body, and has a luminance increasing characteristic such that the emission angle with respect to the normal of the optical sheet is within ± 60 degrees and the luminance of the emitted light is increased. A semiconductor device characterized by aligning the traveling direction of incident light from the outside.   The semiconductor device according to claim 1, wherein the light shielding body is disposed between the optical sheet and an information storage holding unit.   The semiconductor device according to claim 1, wherein the optical sheet is disposed between the light shield and the information storage holding unit.   The semiconductor device according to claim 1, wherein a light shielding member is formed on the surface of the optical sheet so as to overlap therewith. The optical sheet has a condensing function only for light that passes through the optical sheet in one direction,
5. The semiconductor device according to claim 1, wherein the light shielding body and the information storage holding unit are arranged on a side where the light collecting action of the optical sheet is generated.   6. The optical sheet according to claim 1, wherein the optical sheet is a prism sheet in which one surface is a prism surface formed by arranging a number of microprisms and the other surface is a smooth surface. The semiconductor device described in one.   The semiconductor device according to claim 1, wherein at least one surface of the optical sheet has an adhesive action.   The semiconductor device according to claim 1, wherein the optical sheet has a stacked structure in which a plurality of optical sheets are stacked. A backlight module provided on at least one of the front side and the back side of the insulating substrate;
The semiconductor device according to claim 1, wherein the light shielding body and the optical sheet are disposed between the insulating substrate and a backlight module.   The semiconductor device according to claim 1, wherein the information storage holding unit of the nonvolatile memory is a charge holding type.   The semiconductor device according to claim 1, wherein the information storage holding unit of the nonvolatile memory includes a thin film semiconductor element formed on the insulating substrate as a storage element. In a display device provided with the semiconductor device according to any one of claims 1 to 11,
A thin film semiconductor element is formed on an insulating substrate of the semiconductor device, the thin film semiconductor element is used as a storage element of an information storage holding portion of a nonvolatile memory of the semiconductor device, and the thin film semiconductor element is used for driving a display element. A display device including the semiconductor device.   The display device according to claim 12, wherein the nonvolatile memory of the semiconductor device stores a gamma correction value used for controlling the display device or a voltage correction value of an electrode of the counter substrate constituting the display device.   The semiconductor device according to claim 1, wherein the light shielding body and the optical sheet are respectively provided on a front side and a back side of the insulating substrate.   The display device according to claim 12, wherein the light shielding body and the optical sheet are provided on a front side and a back side of the insulating substrate, respectively.   A portable device comprising the display device according to any one of claims 12, 13, and 15.

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