JP2006120768A - Transfer method of thin-film element, and thin-film circuit device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for realizing high performance thin-film circuit device by effectively transferring thin-film elements to a substrate and with high accuracy according to the circuit configuration. <P>SOLUTION: The transfer method of thin film element comprises a bonding agent coating process to form a thin-film element 16 and a bonding agent layer 18 having photo-curing properties to an adhesive layer 14 near a thin-film element 16 to a carrier substrate 10, including a light transparent adhesive layer 14 formed to a light-transmitting substrate 12 and a light-shielding thin-film element 16 on the adhesive layer 14; a light irradiation process for hardening the adhesive agent layer 18, except for the region shielded from the light with the thin film element 16 through the irradiation of the light 1 of the wavelength sensed by the adhesive agent layer 18 from the side of the light-transmitting substrate 12; a bonding process for bonding the thin-film element 16 and the substrate 20 to be transferred by means of the non-sensitive bonding agent layer 18 shielded from light with the thin-film element 16 with the carrier substrate 10 stuck fast to the substrate 20; and a method of removing, from the substrate 20 as the destination of transfer, the adhesive layer 14, unwanted adhesive agent layer 18 and light-transmitting substrate 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for transferring a thin film element formed on a translucent substrate to another substrate to be transferred and a thin film circuit device using the transferred thin film element.

  Forming a functional element such as a thin film transistor on a silicon substrate or a glass substrate, and transferring the functional element onto a relatively low heat resistant substrate such as a resin substrate to realize a thin film circuit device mounted with a thin film element Is being considered. This is because a thin film transistor having good characteristics cannot be manufactured using a substrate having relatively low heat resistance such as a resin substrate. For this reason, a method of transferring a functional element having a required characteristic using a substrate having good heat resistance and crystallinity to a resin substrate or the like has been studied.

  Furthermore, a method of forming a wiring conductor having a predetermined shape on a substrate and then transferring the wiring conductor onto another substrate to be transferred has been studied. In the formation of the wiring conductor by such transfer, a technique for reliably transferring is required to prevent occurrence of transfer failure.

  On the other hand, when transferring onto a substrate to be transferred such as a resin substrate, an adhesive layer having a characteristic that the adhesiveness is reduced by ultraviolet irradiation or heat treatment is used to prevent transfer failure and disconnection of wiring conductors. The method is shown (for example, refer patent document 1). FIG. 9 is a process cross-sectional view illustrating this transfer method.

  First, an adhesive layer 320 whose adhesive strength is reduced by light irradiation is formed on one surface of a transparent resin film 310. Next, a metal foil is stuck on the adhesive layer 320. Further, this metal foil is etched into a predetermined pattern using a photoetching method. Thereby, a state in which the wiring conductor 330 is formed on the adhesive layer 320 as shown in FIG. 9A is obtained.

  Next, as shown in FIG. 9B, the wiring conductor 330 is embedded in the transfer substrate 340 on which the wiring conductor is to be formed. This embedding is performed by using an insulating sheet made of a semi-cured resin as the substrate to be transferred 340, and superposing and bonding the transfer substrate 340 and the resin film 310 on which the wiring conductor 330 is formed.

  Next, as shown in FIG. 9C, the adhesive layer 320 is converted into a non-adhesive layer 320a by irradiating light 350 such as ultraviolet rays from the resin film 310 side. As a result, the wiring conductor 330 and the non-adhesive layer 320a can be easily separated.

  Next, as shown in FIG. 9D, the resin film 310 is peeled from the transferred substrate 340 together with the non-adhesive layer 320a to form a thin film circuit in which the wiring conductor 330 is embedded in the transferred substrate 340. . Thereafter, the circuit board is formed by thermally curing the transfer substrate 340.

  9 shows an example in which the wiring conductor 330 is completely embedded in the transferred substrate 340. However, the wiring conductor 330 may be embedded so as not to peel from the transferred substrate 340. Yes.

  In this forming method, polyester, polyimide, polypropylene, or the like is used as the material of the resin film 310, and acrylic, silicone, or epoxy photocurable resin is used as the material of the adhesive layer 320.

  Similarly, adjusting the adhesive force of the adhesive layer applied to the transfer sheet is also shown as a method for solving the problem of transfer failure and dimensional error. In this method, a metal layer is formed in a transfer sheet comprising a resin film, an adhesive layer provided on one surface of the resin film, and a metal layer on a circuit pattern formed on the adhesive layer. The adhesive strength of the non-surface is set smaller than the adhesive strength of the surface on which the metal layer is formed. By setting in this way, it is possible to effectively prevent positional displacement of the conductor circuit, entrainment of bubbles, etc. when the conductor circuit is transferred by superimposing the insulating substrate and the transfer sheet (for example, Patent Document 2). reference).

  Furthermore, using a circuit transfer tape in which a wiring conductor made of a metal foil is formed on the surface of an adhesive tape, the surface on which the wiring conductor is formed is pressure-bonded to an insulating substrate, and the wiring conductor is bonded to the insulating substrate for transfer. Shows a method of irradiating light from the adhesive tape side of the circuit transfer tape to crosslink the photocrosslinking adhesive and reducing the adhesive force to bond (for example, see Patent Document 3).

Also, apply a UV-curing adhesive on the wiring conductor formed on the transparent film, and irradiate ultraviolet rays from the opposite side of the transparent film so that only the wiring conductor portion has adhesiveness, and then mold this wiring conductor. A method of pressure-transferring onto a body is also shown (for example, see Patent Document 4).
Japanese Patent Laid-Open No. 10-173316 Japanese Patent Laid-Open No. 10-178255 JP 2004-88039 A Japanese Patent Laid-Open No. 62-232990

  In the first and second examples, at least a part of the wiring conductor is embedded in the substrate, and it is easy to manufacture a single-layer circuit substrate. However, it is difficult to repeatedly perform transfer on the same substrate to constitute a highly functional thin film circuit device.

  The third example is a technique for transferring a metal foil, and it seems that it is difficult to transfer a thin film element, such as a thin film capacitor or a thin film resistor, which is very thin compared to the metal foil using this technique. It is. Furthermore, it is difficult to transfer the image on the same substrate.

  Further, in the fourth example, ultraviolet rays are irradiated through a transparent film, and an ultraviolet curing adhesive excluding a region portion shielded from light by a wiring conductor is cured to lose adhesiveness, and then adhered to a molded body. Although it is pressure-transferred, there is no particular description about the method for peeling the transparent film from the circuit pattern. In this example, only the wiring conductor formed with the conductive paste is formed on the transparent film, so even if the transparent film is peeled off after pressure transfer, the wiring conductor is unlikely to remain on the transparent film side. I think that the. However, this method cannot once transfer various thin film elements formed on another substrate as in the present invention to a carrier substrate.

  With the recent thinning and high functionality of portable electronic devices, thinner electronic circuits are formed by forming resistors and capacitors using thin film technology and thick film technology, compared to the conventional electronic circuits that mount chip components. The realization of One method for realizing such an electronic circuit is to manufacture a thin film circuit by a transfer method. However, it is difficult to manufacture a thin film circuit device that satisfies these requirements by the transfer method according to the conventional technique.

  The present invention solves the above-mentioned conventional problems, and various thin film-like elements formed by thin film technology or thick film technology are efficiently and accurately transferred to a substrate according to the circuit configuration to achieve high performance. It is an object to provide a method for realizing a thin film circuit device.

  In order to solve the above-described problems, the thin film element transfer method of the present invention comprises a light-transmitting adhesive layer formed on one surface of a light-transmitting substrate and a light-shielding thin film adhered to the adhesive layer. An adhesive coating process for forming at least a photocurable adhesive layer on the thin film element and the adhesive layer in the vicinity of the thin film element and a carrier substrate having the element, and the adhesive layer is exposed from the translucent substrate side. A light irradiation step of curing the adhesive layer excluding the region shielded by the thin film element by irradiating light of a wavelength to be lighted, and an unexposed light shielded by the thin film element by closely contacting the carrier substrate and the transfer substrate Adhesion process for adhering thin film element and transferred substrate with adhesive layer, adhesive layer and adhesive layer excluding bonding area between thin film element and transferred substrate, and translucent substrate are removed from transferred substrate Process.

  By this method, a thin film element formed on another substrate can be adhered to the carrier substrate, and then the thin film element can be transferred to a set position on the transfer substrate. Therefore, as a thin film element, for example, a resistor, a capacitor, a piezoelectric element, a sensor, or a thin film transistor formed by a thin film technique or a thick film technique can be transferred to a transfer substrate.

  Further, in the above method, the adhesive layer is made of a material having a characteristic of reducing the adhesive force when irradiated with light, and the thin film element is adhered by irradiating light sensitive to the adhesive layer in the light irradiation step. It is good also as a method of reducing the adhesive force of an area | region part. By irradiating the adhesive layer with light using such an adhesive material, the adhesive layer can be more easily separated from the thin film element after the thin film element is transferred to the transfer substrate.

  Further, in the above method, the photosensitive wavelength of the adhesive layer and the photosensitive wavelength of the adhesive layer have different characteristics. In the light irradiation step, after the first light irradiation for reducing the adhesive strength of the adhesive layer, the adhesion is performed. It is good also as a method of performing the 2nd light irradiation which hardens an agent layer. By performing two-stage light irradiation using the pressure-sensitive adhesive layer and the adhesive layer having such characteristics, the adhesive force between the light-sensitive pressure-sensitive adhesive layer and the adhesive layer can be ensured. Therefore, after the thin film element is transferred onto the transfer substrate, the adhesive layer and the unnecessary adhesive layer can be reliably separated together with the translucent substrate.

  In the above method, the thin film element may be a method using an element having light reflectivity. Further, the thin film element may be a method using an element provided with a metal layer. Further, the sum of the amount of incident light from the translucent substrate side and the amount of reflected light reflected from the thin film element may be equal to or greater than the exposure amount for reducing the adhesive strength of the adhesive layer. Furthermore, when performing light irradiation from the translucent substrate side, you may make it irradiate the light quantity smaller than the exposure amount for an adhesion layer to lose adhesive force.

  By adopting such a method, the adhesive strength of the region where the thin film element is adhered is reduced, but the adhesive force between the adhesive layer and the adhesive layer can be kept relatively large. Become. Therefore, after the thin film element is transferred to the transfer substrate, the adhesive layer and the adhesive layer can be reliably separated together with the translucent substrate. That is, the thin film element has a light shielding property and generally has a light reflecting property. On the other hand, the adhesive layer is light transmissive, and light incident on the adhesive layer is not reflected. Therefore, when light was irradiated from the translucent substrate side, the amount of incident light from the translucent substrate side and the amount of reflected light reflected from the surface of the thin film element were added to the adhesive layer in the area where the thin film element adhered. The amount of light acts to expose the adhesive layer. However, only the amount of incident light from the translucent substrate side acts on the adhesive layer in contact with the adhesive layer. By utilizing this difference in the amount of light acting on each pressure-sensitive adhesive layer, the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer in the region of the thin film element is reduced, but the adhesiveness with the adhesive layer can be maintained.

  Further, in the above method, using a plurality of carrier substrates in which thin film-like elements having different characteristics are adhered to different translucent substrates, these thin-film elements are transferred to different positions on the same substrate to be transferred. It is good also as a method. Furthermore, the method may further include a step of forming a wiring conductor that connects a plurality of thin-film elements transferred onto the transfer substrate. Alternatively, the substrate to be transferred has a multilayer wiring structure, and electrode terminals are formed on the surface portion of the surface of the substrate to be transferred, excluding the region where the thin film-like element is transferred, and the wiring conductor may be connected to the electrode terminals. .

  The thin film circuit device of the present invention has a configuration using the thin film element transferred to the transfer substrate by the above thin film element transfer method.

  Thus, thin film elements having different characteristics can be transferred onto the surface of the same substrate to be transferred, so that thin film circuit devices can be manufactured with high yield and high productivity. For example, in a conventional thin film circuit device, when a thin film resistor or a thin film capacitor is fabricated on the same substrate, the previously fabricated thin film element has characteristics variation or pattern deformation during the subsequent thin film device fabrication process. May occur. However, in the present invention, these thin film-like elements are formed on different substrates and then transferred, so that such a defect does not occur. As a result, a thin film circuit device with good yield and good productivity can be realized.

  The thin film element transfer method of the present invention is a complex thin film element in which thin film elements having various different characteristics are arranged on different carrier substrates and transferred to a set position on a substrate to be transferred. There is a great effect that the circuit device can be easily manufactured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, since the same code | symbol is attached | subjected about the same component requirement, description may be abbreviate | omitted.

(First embodiment)
FIG. 1 and FIG. 2 are process cross-sectional views illustrating a thin film element transfer method according to the first embodiment of the present invention.

  First, a carrier substrate 10 for transfer as shown in FIG. In order to produce the carrier substrate 10 for transfer, an adhesive layer 14 is first provided on one main surface of the translucent substrate 12. The adhesive layer 14 is desirably made of a material that is non-photosensitive and has a slightly weaker adhesive force than usual. On this adhesive layer 14, at least a light-shielding thin film element 16 is adhered and disposed. Thereby, the carrier substrate 10 for transfer shown in FIG. 1A is obtained.

  The thin film element 16 may be a circuit pattern made of a simple wiring conductor, or may be a passive element such as a resistance element or a capacitor element, or a functional element such as a thin film transistor, sensor, light emitting element, or light receiving element. . These can be formed on the adhesive layer 14 by forming a necessary thin film by vapor deposition, sputtering, chemical vapor deposition (CVD), or the like, and through a photolithography process and an etching process. Alternatively, these may be formed on another element forming substrate and transferred onto the adhesive layer 14. For example, if the thin film element 16 is formed on the element forming substrate, and the thin film element 16 is attached to the adhesive layer 14, then the element forming substrate is removed with a predetermined chemical solution, etching gas, or the like. It is possible to obtain an adhesive state on the top. In this case, it is necessary to select a material so that the thin film element 16, the adhesive layer 14, and the translucent substrate 12 are not attacked by a chemical solution or an etching gas that corrodes the element formation substrate. For example, when a magnesium oxide (MgO) substrate is used as the element formation substrate, the MgO substrate can be removed by being attacked by a phosphoric acid solution. Therefore, when a piezoelectric element or other thin film element is formed on the MgO substrate, The thin film element 16 may be made of a material that is not affected by these elements. In addition, when a silicon substrate is used as the element formation substrate, the silicon substrate can be removed by being attacked not only by a chemical solution such as a hydrofluoric acid solution or an alkaline solution, but also by dry etching containing fluorine gas, chlorine gas, etc. Similarly, a material that is not affected by these may be used as the element 16. In particular, when removing by dry etching, it is easy not to be exposed to gas, so the degree of freedom in material selection can be increased.

  Next, as shown in FIG. 1B, an adhesive layer 18 is applied on the thin film element 16 and the adhesive layer 14 in the vicinity thereof. The adhesive layer 18 is made of a material that is cured by irradiation with light such as ultraviolet rays.

  Next, as shown in FIG.1 (c), the light 1 of the wavelength which the adhesive bond layer 18 exposes is irradiated from the translucent board | substrate 12 side. Except for the region shielded from light by the thin film element 16 by this light irradiation, the adhesive layer 18 is cured to become a cured adhesive layer 181.

  Next, as shown in FIG. 1D, the adhesive layer 18 in which the region shielded from light by the thin film element 16 becomes the cured adhesive layer 181 is brought into close contact with the transfer substrate 20 together with the carrier substrate 10. In this state, the adhesive layer 18 in the region shielded from light by the thin film element 16 is cured. This curing may be performed by irradiating light having a wavelength at which the adhesive layer 18 is exposed from the transferred substrate 20 side as long as the transferred substrate 20 has translucency. Further, when the substrate 20 to be transferred is an opaque substrate, it may be cured by heating. As a result, the region shielded from light by the thin film element 16 is also cured to become a cured adhesive layer 181, and the thin film element 16 and the transferred substrate 20 are firmly bonded.

  Next, as shown in FIG. 2, the translucent substrate 12 is separated. At this time, the cured adhesive layer 181 other than the region where the adhesive layer 14 and the thin film element 16 are bonded is also separated together with the translucent substrate 12. As a result, the thin film element 16 bonded and fixed by the cured adhesive layer 181 is transferred to the transfer substrate 20. Thereafter, if necessary, another thin film element is transferred. In addition, a wiring conductor is formed for connection to these transferred thin-film elements, other electronic components, or electrode terminals provided on the transferred substrate 20. However, it is not illustrated in the present embodiment. The transferred substrate 20 is, for example, a glass substrate, a resin substrate such as an epoxy resin or a polyimide resin, and a circuit pattern may be formed in advance. Further, the circuit pattern may have a multilayer wiring configuration.

  The translucent substrate 12 may be either a flexible film or a rigid sheet, but has good light transmittance such as ultraviolet rays for making the adhesive layer 18 a cured adhesive layer 181. It is necessary to select the material. For example, polyester, polyimide, polypropylene, or the like can be used as the material for the translucent substrate 12. Further, as the adhesive for forming the adhesive layer 18, a thermosetting type, a photocurable type, and a combined heat / light type epoxy resin type adhesive can be used.

  In addition, a plurality of thin film elements can be transferred to the substrate at one time using a series of steps shown in FIGS.

(Second Embodiment)
3 and 4 are process cross-sectional views illustrating a thin film element transfer method according to the second embodiment of the present invention. The carrier substrate 30 includes a translucent substrate 12, an adhesive layer 32 formed on the translucent substrate 12, and a thin film element 16 adhered on the adhesive layer 32. The thin film element 16 can be manufactured by a manufacturing method in which various elements similar to those described in the first embodiment are appropriately set.

  The steps shown in FIGS. 3A and 3B are the same as those in FIGS. 1A and 1B described in the thin film element transfer method of the first embodiment. In the form, the adhesive layer 32 is different from the adhesive layer 14 of the first embodiment. That is, the present embodiment is characterized in that the pressure-sensitive adhesive layer 32 and the adhesive layer 34 are made of materials that are significantly different in wavelength or sensitivity to be exposed. As shown in FIG. 3B, an adhesive layer 34 is formed on the thin film element 16 of the carrier substrate 30 and the adhesive layer 32 in the vicinity thereof, and the adhesive layer 34 and the adhesive layer 32 are photosensitive. However, it uses materials with different photosensitive wavelengths. For example, the sensitivity can be changed by adding not only a resin material having ultraviolet curing properties but also a resin material having thermosetting properties as the adhesive layer 34. Furthermore, if a resin material having an ultraviolet curing property is selected, the photosensitive wavelength of the adhesive layer 32 can be made different. In this case, if the peak wavelength of the adhesive layer 34 is shortened with respect to the peak wavelength to which the adhesive layer 32 is exposed, light irradiation can be performed more easily.

  Next, as shown in FIG. 3C, the light 2 that the adhesive layer 32 sensitizes is irradiated from the translucent substrate 12 side. By this light irradiation, the pressure-sensitive adhesive layer 32 is exposed to a light-sensitive pressure-sensitive adhesive layer 321 that has lost its adhesiveness. However, since the thin film element 16 is also held by the adhesive layer 34, it is likely to fall off the translucent substrate 12. This phenomenon does not occur. On the other hand, the adhesive layer 34 hardly changes with the light 2.

  Next, as shown in FIG. 3D, light 3 is further irradiated from the translucent substrate 12 side. Since the light 3 at this time is a wavelength at which the adhesive layer 34 is exposed to light and cured, the region other than the region of the adhesive layer 34 that is shielded from light by the thin-film element 16 is exposed to light and cured, and cured adhesive. It becomes the agent layer 341. The pressure-sensitive adhesive layer 32 that is in contact with the adhesive layer 34 becomes a light-sensitive pressure-sensitive adhesive layer 321 by irradiation with light 2. Therefore, when the adhesive layer 34 is cured by irradiation with the light 3, the cured adhesive layer 341 adheres to the photosensitive adhesive layer 321. As a result, as shown in FIG. 3D, when the light 3 is irradiated, the light-sensitive adhesive layer 321 and the cured adhesive layer 341 are bonded, and the thin film element 16 and the light-sensitive adhesive layer 321 are bonded. Is in a state where it is not sticky and can be separated. Further, the adhesive layer 34 in the region shielded from light by the thin film element 16 remains unexposed.

  Next, as shown in FIG. 4A, the carrier substrate 30 in such a state is brought into close contact with the transfer substrate. At this time, no adhesive or the like needs to be applied to the transfer substrate 36. The adhesive layer 34 in the non-photosensitive area is cured in the closely contacted state. At this time, if the transferred substrate 36 has translucency, the light 3 may be irradiated from the transferred substrate 36 side to be cured. Alternatively, heat curing may be performed. By this curing, the adhesive layer 34 in this region also becomes a cured adhesive layer 341, and the thin film element 16 is bonded to the transfer substrate 36 by the cured adhesive layer 341. On the other hand, the region that has already become the cured adhesive layer 341 does not change even if it is in close contact with the transfer substrate 36 and is irradiated with light 3 or heated, and does not adhere to the transfer substrate 36.

  After the thin film element 16 is bonded to the transfer substrate 36 in this way, the translucent substrate 12 is separated as shown in FIG. At this time, the light-sensitive adhesive layer 321 and the cured adhesive layer 341 adhered to the light-sensitive adhesive layer 321 together with the translucent substrate 12 are also separated. As a result, a state in which the thin film element 16 is transferred to the transfer substrate 36 by the cured adhesive layer 341 is obtained. Moreover, since the cured adhesive layer 341 for transfer exists only in the lower region of the thin film element 16, another thin film element can be transferred to the surface of the substrate to be transferred 36 by the same method. . Therefore, since the wiring conductor which connects them can be easily formed, a predetermined thin film circuit device can be easily produced using the transferred thin film element.

(Third embodiment)
5 and 6 are process cross-sectional views illustrating a thin film element transfer method according to the third embodiment of the present invention.

  The steps shown in FIGS. 5A and 5B are the same as those shown in FIGS. 1A and 1B described in the thin film element transfer method of the first embodiment. In the form, the adhesive layer 42 and the adhesive layer 44 are different from the adhesive layer 14 and the adhesive layer 18 of the first embodiment, respectively. The carrier substrate 40 is composed of a translucent substrate 12, an adhesive layer 42 formed on the translucent substrate 12, and the thin film element 16 adhered on the adhesive layer 42. The thin film element 16 can be manufactured by a manufacturing method in which various elements similar to those described in the first embodiment are appropriately set.

  That is, in the present embodiment, the adhesive layer 42 has a characteristic that the adhesive force is reduced by receiving the set amount of light, and in the region where the thin film element 16 is adhered, the adhesive layer 42 is from the translucent substrate 12 side. It has a characteristic that the adhesiveness is lowered by the light amount obtained by adding the incident light amount and the reflected light amount reflected from the thin film element 16. For this reason, the thin film-like element 16 is configured to have not only a light shielding property but also a light reflecting property. For the adhesive layer 44, a resin material that is cured by the amount of incident light irradiated from the translucent substrate 12 side is selected.

  As shown in FIG. 5C, the light 4 is irradiated from the light-transmitting substrate 12 side to the configuration including the pressure-sensitive adhesive layer 42 and the adhesive layer 44. By the irradiation of the light 4, the adhesive layer 44 is cured to become a cured adhesive layer 441. On the other hand, regarding the adhesive layer 42, the effect of irradiation with the light 4 is different between the region in contact with the adhesive layer 44 and the region in contact with the thin film element 16 as follows. Since the thin film element 16 has light reflectivity, the adhesive layer 42 in this region is reflected from the surface of the thin film element 16 in addition to the amount of light 4 from the translucent substrate 12 side, and the adhesive layer. 42 receives the amount of reflected light returning into 42. As a result, the adhesive layer 42 becomes a photosensitive adhesive layer 421 that has been exposed to light and has lost its adhesiveness. On the other hand, in the region in contact with the adhesive layer 44, the light 4 from the translucent substrate 12 side enters the adhesive layer 44 and there is almost no reflected light reflected on the adhesive layer 42 side. For this reason, the adhesive layer 42 in this region maintains a state where the adhesiveness is maintained. That is, the adhesive layer 42 and the cured adhesive layer 441 in this region are in a bonded state.

  As a result, as shown in FIG. 5 (c), the adhesive layer 42 and the cured adhesive layer 441 are bonded, and the thin film element 16 and the photosensitive adhesive layer 421 are no longer sticky and can be separated. It is in a state. Further, the adhesive layer 44 in the region shielded from light by the thin film element 16 is maintained in an unexposed state.

  Next, as shown in FIG. 5D, the carrier substrate 40 in such a state is brought into close contact with the transfer substrate 46. At this time, no adhesive or the like need be applied to the transfer substrate 46. The adhesive layer 44 in the non-photosensitive area is cured in the state of being in close contact. At this time, if the transferred substrate 46 has translucency, the light 4 may be irradiated from the transferred substrate 46 side to be cured. Alternatively, heat curing may be performed. By this curing, the adhesive layer 44 in this region also becomes a cured adhesive layer 441, and the thin film element 16 is bonded to the transfer substrate 46 by the cured adhesive layer 441. On the other hand, the region that has already become the cured adhesive layer 441 does not change even when it is in close contact with the transfer substrate 46 and is irradiated with light 4 or heated, and does not adhere to the transfer substrate 46.

  After the thin film element 16 is bonded to the transfer substrate 46 as described above, the translucent substrate 12 is separated as shown in FIG. At this time, the adhesive layer 42 together with the translucent substrate 12, the cured adhesive layer 441 adhered to the adhesive layer 42, and the photosensitive adhesive layer 421 in the region of the thin film element 16 are also separated. As a result, a state where the thin film element 16 is transferred to the transfer substrate 46 by the cured adhesive layer 441 is obtained. In addition, since the cured adhesive layer 441 for transfer exists only in the lower region of the thin film element 16, another thin film element can be transferred to the surface of the substrate 46 to be transferred by the same method. . Therefore, since the wiring conductor which connects them can be easily formed, a predetermined thin film circuit device can be easily produced using the transferred thin film element.

  If the thin film element has light reflectivity, the sum of the amount of incident light from the translucent substrate side and the amount of reflected light reflected from the thin film element reduces the amount of exposure for reducing the adhesive strength of the adhesive layer. What is necessary is just to make it above, Furthermore, when performing light irradiation from the translucent board | substrate side, it should be made to irradiate by setting appropriately the light quantity smaller than the exposure amount for an adhesion layer to lose adhesive force. Also good. Even if such a light amount is irradiated, the substantial light amount is different between the adhesive layer in the thin film element region and the adhesive layer in the other region, and the adhesive force of the adhesive layer in the thin film element region is further increased. It can also be reduced.

(Fourth embodiment)
7 and 8 are process cross-sectional views illustrating a thin film element transfer method according to the fourth embodiment of the present invention. The thin film element transfer method according to the present embodiment is characterized in that different thin film elements formed on different carrier substrates are transferred onto the same substrate.

  First, a method for transferring the first thin film element will be described. FIG. 7A is a cross-sectional view of the carrier substrate 50 manufactured through the same process as that shown in FIG. 5A and in which the first thin film element 56 is adhered to the translucent substrate 52 by the adhesive layer 54. FIG. In the present embodiment, a plurality of first thin film elements 56 are arranged on the carrier substrate 50. The first thin film element 56 is, for example, a thin film capacitor, a thin film resistor, a thin film transistor, a printing resistor, a printed capacitor, a sensor, or a wiring conductor.

  Next, as shown in FIG. 7B, an adhesive layer 58 is applied on the first thin film element 56 to be transferred and the adhesive layer 54 in the vicinity thereof. In the present embodiment, the case where the pressure-sensitive adhesive layer 54 and the adhesive layer 58 are formed using the same material structure as the material used in the third embodiment will be described.

  Next, as shown in FIG. 7C, similarly to the third embodiment, the light 5 such as ultraviolet rays is locally applied from the translucent substrate 52 side to the region of the first thin film element 56 to be transferred. Irradiate. By the irradiation of this light 5, the adhesive layer 54 in the region of the first thin film element 56 to be transferred becomes a photosensitive adhesive layer 541 that has been exposed to light and has lost its adhesiveness. On the other hand, the adhesive layer 54 in the region in contact with the adhesive layer 58 does not lose its adhesiveness when irradiated with the light 5. In addition, the adhesive layer 58 in this region is cured by irradiation with the light 5 to become a cured adhesive layer 581 and adheres to the adhesive layer 54.

  As shown in FIG. 7D, the carrier substrate 50 in such a state is brought into close contact with the transfer substrate 60. In this case, it is desirable to use a transparent film such as a polyethylene terephthalate (PET) resin for the light-transmitting substrate 52 in order to facilitate adhesion. At this time, no adhesive or the like need be applied to the transfer substrate 60. The adhesive layer 58 in the non-photosensitive area is cured in the state of being in close contact. At this time, if the transferred substrate 60 has translucency, the light 5 may be irradiated from the transferred substrate 60 side to be cured. Alternatively, heat curing may be performed. By this curing, the adhesive layer 58 in this region also becomes a cured adhesive layer 581, and the first thin film element 56 is bonded to the transfer substrate 60 by the cured adhesive layer 581. On the other hand, the region that has already become the cured adhesive layer 581 does not change even if it is in close contact with the transfer substrate 60 and is irradiated with light 5 or heated, and does not adhere to the transfer substrate 60.

  After the first thin film element 56 is bonded to the transfer substrate 60 in this way, the translucent substrate 52 is separated as shown in FIG. At this time, the adhesive layer 54 together with the translucent substrate 52, the cured adhesive layer 581 adhered to the adhesive layer 54, and the photosensitive adhesive layer 541 in the region of the first thin film element 56 are also separated. Thereby, the first thin film element 56 is transferred onto the set surface of the transfer substrate 60. The other first thin film element 56 disposed on the translucent substrate 52 is used when transferring to another transferred substrate.

  Next, a method for transferring the second thin film element to a predetermined position in the vicinity of the first thin film element 56 of the same substrate to be transferred 60 will be described.

  As shown in FIG. 8A, a carrier substrate 70 is prepared in which a second thin film element 76 is adhered on the surface of the translucent substrate 72 on which the adhesive layer 74 is provided. Note that the translucent substrate 72 and the adhesive layer 74 are preferably made of the same material as described above.

  Next, as shown in FIG. 8B, an adhesive layer 78 is applied on the second thin film element 76 to be transferred and the adhesive layer 74 in the vicinity thereof. Also in this case, the adhesive layer 74 and the adhesive layer 78 have the same material configuration as described above.

  Next, as shown in FIG. 8C, similarly to the case shown in FIG. 7C, light 6 such as ultraviolet rays is transmitted from the translucent substrate 72 side to the region of the second thin film element 76 to be transferred. Is irradiated locally. By the irradiation of the light 6, the adhesive layer 74 in the region of the second thin film element 76 to be transferred becomes a photosensitive adhesive layer 741 that has been exposed to light and has lost its adhesiveness. On the other hand, the adhesive layer 74 in the region in contact with the adhesive layer 78 does not lose its adhesiveness when irradiated with the light 6. In addition, the adhesive layer 78 in this region is cured by irradiation with the light 6 to become a cured adhesive layer 781 and is adhered to the adhesive layer 74.

  As shown in FIG. 8D, the carrier substrate 70 in such a state is brought into close contact with the transfer substrate 60. At this time, since the position where the second thin film element 76 is bonded to the transfer substrate 60 is often close to the first thin film element 56, the translucent substrate 72 is used for easy adhesion. For example, it is desirable to use a transparent film such as polyethylene terephthalate (PET) resin. Note that no adhesive or the like need be applied to the transfer substrate 60. The adhesive layer 78 in the non-photosensitive area is cured in the state of being in close contact. At this time, if the transfer substrate 60 has translucency, the light 6 may be irradiated from the transfer substrate 60 side to be cured. Alternatively, heat curing may be performed. By this curing, the adhesive layer 78 in this region also becomes a cured adhesive layer 781, and the second thin film element 76 is bonded to the transfer substrate 60 by the cured adhesive layer 781. On the other hand, the region that has already become the cured adhesive layer 781 does not change even if it is in close contact with the transfer substrate 60 and is irradiated with light 6 or heated, and does not adhere to the transfer substrate 60.

  After the second thin film element 76 is bonded to the transfer substrate 60 in this way, the translucent substrate 72 is separated. At this time, the adhesive layer 74 together with the translucent substrate 72, the cured adhesive layer 781 adhered to the adhesive layer 74, and the photosensitive adhesive layer 741 in the region of the second thin film element 76 are also separated. As a result, the second thin film element 76 is transferred onto the set surface of the transfer substrate 60. As a result, the first thin film element 56 and the second thin film element 76 are provided on the same plane of the transfer substrate 60, and the first thin film element 56, the second thin film element 76, A structure in which the surface of the substrate to be transferred 60 is directly exposed is obtained in a region other than the region where the film is transferred. Furthermore, when another thin film-like element is transferred onto the transfer substrate 60, the same steps as in FIGS. 7 and 8 may be repeated.

  The other second thin film element 76 disposed on the translucent substrate 72 is used when transferring to another substrate to be transferred.

  Next, as shown in FIG. 8E, a thin film circuit device can be obtained by forming a wiring conductor 80 including the first thin film element 56 and the second thin film element 76 and connecting them together. It is done. The wiring conductor 80 may be formed by a method such as mask vapor deposition or may be formed by printing. Further, a metal thin film may be formed on the entire surface by vapor deposition or the like, and then a pattern may be formed by a photolithography process and an etching process.

  At this time, the substrate to be transferred 60 may have a multilayer wiring configuration, electrode terminals may be provided at predetermined positions on the surface, and connection with these electrode terminals may be performed by the wiring conductor 80.

  As described above, a plurality of carrier substrates in which various thin film elements having different electrical characteristics, manufacturing processes, or materials are arranged on the respective transparent substrates are prepared, and the thin film elements are formed using these carrier substrates. Are sequentially transferred onto the substrate to be transferred, a complicated thin film circuit device can be easily formed.

  Conventionally, when thin film elements having various different characteristics are formed on the same substrate, the manufacturing process is complicated and the yield is deteriorated, so that the productivity cannot be improved. For example, when a process for forming a thin film capacitor is performed, the yield as a thin film circuit device may be reduced because it adversely affects other thin film elements that have already been formed, for example, the characteristics and pattern shape of thin film resistors. There were many. However, in the present invention, the separate thin film-like elements produced separately are sequentially transferred onto the same substrate, so that the manufacturing process is greatly simplified and the productivity can be improved. In addition, if the characteristics of the thin film element are checked and only good products are transferred while being arranged on the translucent substrate, a thin film circuit device can be realized with a higher yield.

  The translucent substrate may be a flat plate as long as it has a property of transmitting light having a wavelength that sensitizes the adhesive layer, but if a flexible sheet is used, the transfer workability is improved. So desirable. Further, this sheet may be used in the form of a roll.

  In the thin film device transfer method of the present invention, various thin film devices formed by thin film technology or thick film technology are efficiently and accurately transferred to a substrate according to the circuit configuration, and a high performance thin film circuit is obtained. Since the device can be realized, it is useful in the field of electronic equipment that is required to be small, thin, and highly functional.

Process sectional drawing explaining the transfer method of the thin film element concerning the 1st Embodiment of this invention Process sectional drawing explaining the transfer method of the thin film element concerning the embodiment Process sectional drawing explaining the transfer method of the thin film element concerning the 2nd Embodiment of this invention Process sectional drawing explaining the transfer method of the thin film element concerning the embodiment Process sectional drawing explaining the transfer method of the thin film element concerning the 3rd Embodiment of this invention Process sectional drawing explaining the transfer method of the thin film element concerning the embodiment Process sectional drawing explaining the transfer method of the thin film element concerning the 4th Embodiment of this invention Process sectional drawing explaining the transfer method of the thin film element concerning the embodiment Cross-sectional process diagram for explaining a conventional transfer method using an adhesive layer having a characteristic that the adhesiveness is reduced by ultraviolet irradiation or heat treatment

Explanation of symbols

1, 2, 3, 4, 5, 6, 350 Light 10, 30, 40, 50, 70 Carrier substrate 12, 52, 72 Translucent substrate 14, 32, 42, 54, 74, 320 Adhesive layer 16 Thin film Element 18, 34, 44, 58, 78 Adhesive layer 20, 36, 46, 60, 340 Transferred substrate 56 First thin film element 76 Second thin film element 80, 330 Wiring conductors 181, 341, 441 581,781 Cured adhesive layer 310 Resin film 320a Non-adhesive layer 321,421,541,741 Photosensitized adhesive layer

Claims (11)

With respect to a carrier substrate having a translucent adhesive layer formed on one surface of a translucent substrate and a light-shielding thin film element adhered on the adhesive layer, the thin film element and the vicinity thereof An adhesive application step of forming an adhesive layer having at least photocurability on the adhesive layer;
A light irradiation step of irradiating light of a wavelength at which the adhesive layer is exposed from the translucent substrate side and curing the adhesive layer excluding a region shielded by the thin film element; and
An adhesion step in which the carrier substrate and the transfer substrate are brought into close contact with each other and the thin film element and the transfer substrate are bonded by the non-photosensitive adhesive layer shielded from light by the thin film element;
A step of removing the adhesive layer and the adhesive layer excluding an adhesive region between the thin film-like element and the transferred substrate from the transferred substrate together with the translucent substrate. Transfer method. The pressure-sensitive adhesive layer is made of a material having a property of reducing the adhesive strength upon receiving light irradiation,
2. The thin film element transfer method according to claim 1, wherein in the light irradiation step, the adhesive force of the region where the thin film element is adhered is reduced by irradiating light that the adhesive layer is exposed to. . The photosensitive wavelength of the adhesive layer and the photosensitive wavelength of the adhesive layer have different characteristics,
The said light irradiation process WHEREIN: After performing the 1st light irradiation which reduces the adhesive force of the said adhesion layer, the 2nd light irradiation which hardens the said adhesive bond layer is performed. Method for transferring thin film element. 3. The method for transferring a thin film element according to claim 2, wherein the thin film element has light reflectivity. 5. The method for transferring a thin film element according to claim 4, wherein the thin film element comprises a metal layer. 5. The sum of the amount of incident light from the translucent substrate side and the amount of reflected light reflected from the thin film element is equal to or greater than an exposure amount for reducing the adhesive strength of the adhesive layer. The method for transferring a thin film element according to claim 5. The light quantity smaller than the exposure amount for the said adhesion layer to lose adhesive force is irradiated when light irradiation is performed from the said translucent board | substrate side, The any one of Claim 4-6 characterized by the above-mentioned. A method for transferring a thin film-like element as described. Using the plurality of carrier substrates obtained by adhering the thin film-like elements having different characteristics onto different translucent substrates, and transferring the thin-film elements to different positions on the same substrate. The method for transferring a thin film element according to any one of claims 1 to 7. 9. The method for transferring a thin film element according to claim 8, further comprising a step of forming a wiring conductor that connects the plurality of thin film elements transferred onto the transfer substrate. The substrate to be transferred has a multilayer wiring configuration, and electrode terminals are formed on the surface of the substrate to be transferred except for a region to which the thin film element is transferred, and the wiring conductor is also connected to the electrode terminals. The method for transferring a thin film element according to claim 9. A thin film circuit device using a thin film element transferred to a transfer substrate by the thin film element transfer method according to claim 1.

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