Electronic component, method for producing same, and sealing material paste used in same
09728341 · 2017-08-08
Assignee
Inventors
- Takashi NAITO (Tokyo, JP)
- Shinichi Tachizono (Tokyo, JP)
- Kei Yoshimura (Tokyo, JP)
- Yuji Hashiba (Tokyo, JP)
- Motomune Kodama (Tokyo, JP)
- Masanori Miyagi (Tokyo, JP)
- Takuya AOYAGI (Tokyo, JP)
- Yuichi Sawai (Tokyo, JP)
- Tadashi Fujieda (Tokyo, JP)
- Takeshi Tsukamoto (Tokyo, JP)
- Hajime Murakami (Tokyo, JP)
Cpc classification
Y02P70/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B32B17/10018
PERFORMING OPERATIONS; TRANSPORTING
H01L2924/0002
ELECTRICITY
Y02E10/542
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B32B37/12
PERFORMING OPERATIONS; TRANSPORTING
B32B3/06
PERFORMING OPERATIONS; TRANSPORTING
Y02E10/549
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01L2924/0002
ELECTRICITY
B32B17/10119
PERFORMING OPERATIONS; TRANSPORTING
B32B38/0008
PERFORMING OPERATIONS; TRANSPORTING
B32B7/14
PERFORMING OPERATIONS; TRANSPORTING
H10K50/8426
ELECTRICITY
H01L2924/00
ELECTRICITY
H01M14/00
ELECTRICITY
B32B2457/206
PERFORMING OPERATIONS; TRANSPORTING
H01G9/2077
ELECTRICITY
C08K2201/008
CHEMISTRY; METALLURGY
B32B37/18
PERFORMING OPERATIONS; TRANSPORTING
H01L2924/00
ELECTRICITY
B32B17/06
PERFORMING OPERATIONS; TRANSPORTING
Y10T428/239
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
C03C8/24
CHEMISTRY; METALLURGY
H01M14/00
ELECTRICITY
B32B17/06
PERFORMING OPERATIONS; TRANSPORTING
B32B38/00
PERFORMING OPERATIONS; TRANSPORTING
B32B37/18
PERFORMING OPERATIONS; TRANSPORTING
B32B37/12
PERFORMING OPERATIONS; TRANSPORTING
B32B7/14
PERFORMING OPERATIONS; TRANSPORTING
B32B3/06
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An electronic component has an organic member between two transparent substrates, in which outer peripheral portions of the two transparent substrates are bonded by a sealing material containing to melting glass. The low melting glass contains vanadium oxide, tellurium oxide, iron oxide and phosphoric acid, and satisfies the following relations (1) and (2) in terms of oxides. The sealing material is formed of a sealing material paste which contains the low melting glass, a resin binder and a solvent, the low melting glass containing vanadium oxide, tellurium oxide, iron oxide and phosphoric acid, and satisfies the following relations (1) and (2) in terms of the oxides. Thereby, thermal damages to an organic element or an organic material contained in the electronic component can be reduced and an electronic component having a glass bonding layer of high reliability can be produced efficiently.
V.sub.2O.sub.5+TeO.sub.2+Fe.sub.2O+P.sub.2O.sub.5≧90(mass %) (1)
V.sub.2O.sub.5>TeO.sub.2>Fe.sub.2O.sub.3>P.sub.2O.sub.5 (mass %) (2)
Claims
1. A sealing material paste comprising: a low melting glass; a resin binder; and a solvent, wherein the low melting glass contains vanadium oxide, tellurium oxide, iron oxide and phosphorous oxide, and satisfies the following relations (1) and (2) in terms of oxides:
V.sub.2O.sub.5+TeO.sub.2+Fe.sub.2O.sub.3+P.sub.2O.sub.5≧90 (mass %) (1)
V.sub.2O.sub.5>TeO.sub.2>Fe.sub.2O.sub.3>P.sub.2O.sub.5 (mass %) (2).
2. The sealing material paste according to claim 1, wherein the low melting glass further contains one or more of tungsten oxide, molybdenum oxide, manganese oxide, zinc oxide, barium oxide, strontium oxide and calcium oxide, and satisfies the following relation (3) in terms of oxides
WO.sub.3+MoO.sub.3+MnO.sub.2+ZnO+BaO+SrO+CaO≦10 mass % (3).
3. The sealing material paste according to claim 1, wherein the low melting glass comprises 35 to 50 mass % of V.sub.2O.sub.5, 20 to 35 mass % of TeO.sub.2, 10 to 20 mass % of Fe.sub.2O.sub.3, and 4 to 15 mass % of P.sub.2O.sub.5 in terms of oxides.
4. The sealing material paste according to claim 1, containing filler particles, wherein the filler particles are one or more of zirconium phosphotungstate (Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2), niobium oxide (Nb.sub.2O.sub.5) and β-eucryptite (LiAlSiO.sub.4).
5. The sealing material paste according to claim 4, wherein the filler particles are zirconium phosphotungstate (Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2), and further contain iron tungstate (FeWO.sub.4) and zirconium phosphate (ZrO(PO.sub.4).sub.2).
6. The sealing material paste according to claim 4, wherein a content of the filler particles is greater than zero and less than or equal to 35 parts by volume based on 100 parts by volume of a powder of the low melting glass.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1)
(2)
(3)
(4)
(5)
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(7)
(8)
(9)
(10)
(11)
(12)
(13)
DESCRIPTION OF EMBODIMENTS
(14) The present invention is described as below.
(15)
(16) In the electronic component shown in
(17)
(18) The present invention has a feature that the low melting glass contained in the sealing materials 5, 5′ contains vanadium oxide, tellurium oxide, iron oxide and phosphorous oxide and satisfies the following relations (1) and (2) in terms of oxides:
V.sub.2O.sub.5+TeO.sub.2+Fe.sub.2O.sub.3+P.sub.2O.sub.5≧90 (mass %) (1)
V.sub.2O.sub.5>TeO.sub.2>Fe.sub.2O.sub.3>P.sub.2O.sub.5 (mass %) (2)
(19) In this specification, the chemical formulas used in numerical formulas represent compositions (numerical values) of the oxides on the mass basis.
(20) The low melting glass satisfying the conditions efficiently absorbs a wavelength of a laser upon laser irradiation and is heated and easily softened and fluidized. That is, heating can be restricted only to desired portions by using the low melting glass and the laser, and the outer peripheral portions of the two transparent substrates 1 and 2 can be bonded at high reliability without giving thermal damages to the organic member 3.
(21) The effective wavelength of the laser used is in a range from 400 to 1100 nm which is absorbed efficiently in the low melting glass and transmits the transparent substrate. When the wavelength is 400 nm or more, the transparent substrate and the organic element or the organic material inside thereof can be prevented from degradation by heating. On the other hand, when the wavelength is at 1100 on or less, the laser tends to be absorbed in the low melting glass, and to show a good softening and fluidizing property. Further, even when a water-containing portion is present, undesired effect on the glass by heating can be prevented.
(22) It is important that the low melting glass contains V.sub.2O.sub.5 by the greatest amount in terms of oxides, by which the glass absorbs a wavelength in a range from 400 to 1100 nm and is heated. Also the transition point T.sub.g and the softening point T.sub.s of the low melting glass can be lowered and the glass can be softened and fluidized by laser irradiation at a wavelength in a range from 400 to 1100 nm.
(23) TeO.sub.2 and P.sub.2O.sub.5 are important ingredients for vitrification. If the material is not glass, it cannot be softened and fluidized at a low temperature. Further, it cannot be readily softened and fluidized also by the laser irradiation. P.sub.2O.sub.5 has a larger vitrifying effect than TeO.sub.2 and is effective for decreasing thermal expansion. However, if the content is more than that of TeO.sub.2, the moisture resistance and water resistance are deteriorated to increase the transition point T.sub.g and the softening point T.sub.s. On the other hand, as the TeO.sub.2 content is increased, while the transition point T.sub.g and the softening point T.sub.s can be lowered, the heat expansion coefficient tends to be larger. If it is excessively large, the low melting glass may sometimes be fractured before softening and fluidization due to thermal shock by the laser irradiation.
(24) Fe.sub.2O.sub.3 is an ingredient that absorbs the laser at the wavelength in the range from 400 to 1100 nm like V.sub.2O.sub.5. When it is contained by an appropriate amount together with V.sub.2O.sub.5, the laser sealed portion of high airtightness and sealability can be obtained even after atmospheric sintering. Further, since Fe.sub.2O.sub.3 is an ingredient that acts on P.sub.2O.sub.5 to improve the moisture resistance and the water resistance of the low melting glass and decrease the thermal expansion, it is necessary that an appropriate amount of Fe.sub.2O.sub.3 is larger than the content of P.sub.2O.sub.5. Further, when the amount is decreased to less than the content of TeO.sub.2, the softening and the fluidizing property of the low melting glass can be kept and crystallization thereof by heating can be prevented.
(25) Respective roles of V.sub.2O.sub.5, TeO.sub.2, Fe.sub.2O.sub.3 and P.sub.2O.sub.5 and advantageous effects thereof described above are developed effectively when the total content of them is 90 mass % or more. If this is less than 90 mass %, the bonded portion of the high reliability (bondability, adhesivity, moisture resistance, water resistance, etc.) by the laser irradiation cannot be obtained.
(26) Further, one or more of tungsten oxide, molybdenum oxide, manganese oxide, zinc oxide, barium oxide, strontium oxide, and calcium oxide is preferably contained as the ingredient of the low melting glass and it is desired to satisfy the following relation (3) in terms of oxides.
WO.sub.3+MoO.sub.3+MnO.sub.2+ZnO+BaO+SrO+F+CaO≦10 mass % (3)
(27) When the total content of them is 10 mass % or less, it is possible to lower the transition point T.sub.g and the softening point T.sub.s, to decrease the heat expansion coefficient, or to suppress the crystallization.
(28) It is effective for further preventing or suppressing crystallization to contain WO.sub.3, MoO.sub.3, ZnO, BaO, SrO and CaO, for improving the moisture resistance and the water resistance to contain MnO.sub.2, BaO, SrO and CaO, for decreasing the heat expansion coefficient to contain ZnO, and for decreasing the temperature of the transition point T and the softening point T.sub.s to contain MoO.sub.3. On the other hand, MnO.sub.2 is an ingredient that promotes crystallization, BaO, SrO and CaO are ingredients that increase the transition point T.sub.g and the softening point T.sub.s, MoO.sub.3, BaO, SrO and CaO are ingredients that increase the heat expansion coefficient, and MoO.sub.3 and ZrO are ingredients that lower the moisture resistance and she water resistance.
(29) Accordingly, containing WO.sub.3, MoO.sub.3, MnO.sub.2, ZnO, BaO, SrO and CaO has advantages and disadvantages respectively, and the ingredients and the contents thereof should be determined while taking a sufficient consideration for the characteristics of the basic composition consisting of V.sub.2O.sub.5, TeO.sub.2, Fe.sub.2O.sub.3 and P.sub.2O.sub.5.
(30) Based on the premise of satisfying the conditions described above, a particularly effective compositional ranges of the low melting glass are 35 to 50 mass % of V.sub.2O.sub.5, 20 to 35 mass % of TeO.sub.2, 10 to 20 mass % of Fe.sub.2O.sub.3, 4 to 15 mass % of P.sub.2O.sub.5, and 0 to 10 mass % of one or more of WO.sub.3, MoO.sub.3, MnO.sub.2, ZnO, BaO, SrO and CaO in total in terms of oxides.
(31) V.sub.2O.sub.5 at 35 mass % or more can provide easy softening and fluidization by the laser irradiation at the wavelength in a range from 400 to 1100 nm. When the content is 50 mass % or less, reliability such as the moisture resistance, the water resistance, etc. is improved. When TeO.sub.2 is at 20 mass % or more, the glass is less crystallized, the transition point T.sub.g and the softening point T.sub.s are lowered and reliability such as the moisture resistance and the water resistance is further improved. When TeO.sub.2 is at 35 mass % or less, the low melting glass can be prevented from fracture before the softening and fluidization by heat shock under the laser irradiation since the heat expansion coefficient is not increased excessively.
(32) When Fe.sub.2O.sub.3 is at 10 mass % or more, the reliability such as the moisture resistance and the water resistance is improved. In addition, an effect of decreasing the thermal expansion can be obtained. Further, a glass bonded portion of high reliability can be obtained in the laser sealing step after atmospheric sintering. When Fe.sub.2O.sub.5 is at 20 mass % or less, crystallization can be suppressed. When P.sub.2O.sub.5 is at 4 mass % or more, the glass is less crystallized. In addition, the glass tends to be softened and fluidized by the laser irradiation. When P.sub.2O.sub.5 is at 15 mass % or less, the transition point T.sub.g and the softening point. T.sub.s are lowered and the glass can be softened and fluidized readily by the laser irradiation. Further, the reliability such as the moisture resistance and the water resistance is also improved.
(33) Further, it is effective for the above-mentioned low melting glass that the transition point T.sub.g is 350° C. or lower and the softening point T.sub.s is 410° C. or lower. As will, be described specifically later, the transition point T.sub.g and the softening point T.sub.s referred to herein are temperature characteristics by a differential thermal analysis (DTA), in which the transition point T.sub.g is a starting temperature of the first endothermic peak and the softening point T is a temperature of a second endothermic peak. If the transition point T.sub.g exceeds 350° C., large residual strains may sometimes occur under laser sealing accompanying rapid heating and cooling. Further, if the softening point T.sub.s exceeds 410° C., the glass is less softened and fluidized readily under laser irradiation. Further, it is effective that the low melting glass has a heat expansion coefficient at 30 to 250° C. of 100×10.sup.−7/° C. or less. If the heat expansion coefficient exceeds 100×10.sup.−7/° C., cracks may sometimes occur by the heat shock under the laser irradiation.
(34) Further, in the present invention, the sealing material 5 in the electronic component illustrated in
(35) For the effect of lowering the heat expansion coefficient of the sealing material 5, it is most effective to contain the filler particles of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2. Further, it is particularly effective that the filler particle contains iron tungstate (FeWO.sub.4) and zirconium phosphate (ZrO(PO.sub.4).sub.2). Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles containing FeWO.sub.4 and ZrO(PO.sub.4).sub.2 can absorb a laser at a wavelength in a range from 400 to 1100 nm and can generate heat. In view of the above, the low melting glass and the filler can be heated simultaneously by the laser irradiation, which provides a significant advantage capable of providing effective laser sealing and obtaining a glass bonded portion of high reliability.
(36) When the content of the filler particles in the sealing material 5 is 35 parts by volume or less based on 100 parts by volume of the low melting glass, the softening and fluidizing property of the low melting glass in the sealing material can be maintained and a firm bonding can be obtained under the laser irradiation.
(37) Further, in the electronic component of the invention illustrated in
(38) Further, in the electronic component of the present invention illustrated in
(39) As described above, the present invention is generally applied effectively to a display containing an organic light emitting diode, a dye-sensitized solar cell containing an organic dye, and a solar cell containing a photoelectronic conversion element and being bonded by a resin, for example. Further, the present invention is not restricted only to the electronic component described above but is applicable also to a case in which an element and a material of low heat resistance is used to the inside of the electronic component and is not restricted only to the electronic component described above.
(40) Further, the present invention provides a sealing material paste containing a powder of the low melting glass, a resin binder and a solvent. The particle diameter of the low melting glass is preferably 3 μm or less as a mean particle diameter. Ethyl cellulose or nitrocellulose is preferred as the resin powder, and butyl carbitol acetate is preferred as the solvent. Instead of the resin binder and the solvent, α-terpineol which is a high viscosity solvent can also be used. Further, the sealing material paste may also contain the filler particles. The particle diameter of the filler particle as a mean particle diameter is preferably larger than the mean particle diameter of the low melting glass. When the content of the filler particles is 35 parts by volume or less based on 100 parts by volume of the powder of the low melting glass, firm bonding is obtained.
(41) Then, a method for producing the electronic component of the present invention is to be described.
(42) A producing method for the electronic component illustrated in
(43) As illustrated in
(44) Then, the other transparent substrate 2 formed with one or more organic member 3 is prepared as illustrated in
(45) Then, the surface of the transparent substrate 1 formed with the sealing material 5 and the surface of the transparent substrate 2 formed with the organic member 3 are opposed, positions of the two transparent substrates 1 and 2 are adjusted, and the organic member 3 is disposed in an inner space surrounded by the transparent substrates 1, 2 and the sealing material 5, as illustrated in
(46) A method of producing the electronic component illustrated in
(47) As illustrated in
(48) The spacer 6 on which the sealing materials 5 and 5′ is formed is disposed and secured at the outer peripheral portions of a space between the transparent substrate 1 and the other transparent substrate 2 formed with one or more of organic members 3 are opposed, as illustrated in
(49) As described above, the electronic component and the producing method thereof, as well as the sealing material paste used therefor according to the present invention, an electronic component can be produced efficiently without giving thermal damages to the organic element or the organic material disposed in the electronic component. In addition, a glass bonding layer excellent in bondability, gas barrier property (airtightness), and moisture resistance and water resistance can be obtained.
(50) Hereinafter, the present invention is to be described more specifically by way of examples. However, the present invention is not restricted to the descriptions of the examples referred to therein but they may be combined appropriately.
EXAMPLE 1
(51) In this example, compositions and characteristics of low melting glasses contained in a sealing material were investigated. Tables 1 to 4 show examples and Table 5 shows comparative examples. For manufacturing low melting glasses illustrated in Tables 1 to 5, reagents of V.sub.2O.sub.5, TeO.sub.2, Fe.sub.2O.sub.3, P.sub.2O.sub.5, WO.sub.3, MoO.sub.3, MnO.sub.2, ZnO, SrCO.sub.3, BaCO.sub.3 and CaCO.sub.3 manufactured by Kojundo Chemical Laboratory Co., Ltd. were used as raw materials. The materials were used and blended and mixed by predetermined amounts so as to be 300 g in total, charged in a platinum crucible, and heated to 900° C. and melted at a temperature elevation rate of 5 to 10° C./min by an electric furnace. They were kept for 2 hours while stirring at that temperature in order to form homogeneous glasses. Then, the crucible was taken out and the molten glass was cast onto a stainless steel sheet previously heated to 150 to 200° C. to prepare low melting glass.
(52) The prepared low melting glass was pulverized by a jet mill to a mean particle diameter of 3 μm or less. By using the powder, a transition point (T.sub.g), a yield point (M.sub.s), a softening point (T.sub.s), and a crystallization temperature (T.sub.cry) were measured by performing differential thermal analysis (DTA) to 500° C. at a temperature elevation rate of 5° C./min. An alumina (Al.sub.2O.sub.2) powder was used as a standard sample.
(53)
(54) Thermal strain was removed from the prepared low melting glass within a temperature range of T.sub.g to M.sub.g and fabricated into a square pole of 4×4×20 mm. Using the pole, a heat expansion coefficient at 30 to 250° C., a transition temperature T.sub.G, and a deformation temperature A.sub.T were measured by a thermal expansion meter. The temperature elevation rate was set to 5° C./min. A quartz glass cylinder of φ5×20 mm was used as a control sample.
(55)
(56) In
(57) A saturated pressure cooker test (at a temperature of 120° C. and a humidity of 100% Rh, and under a pressure 202 kPa) was used for moisture resistance test of the prepared low melting glass, and a sample which applied a mirror-like finishing to a surface thereof for the evaluation of thermal expansion was used as a sample for evaluating the moisture resistance. For the evaluation of the moisture resistance, an saturated pressure cooker test was performed for three days, and evaluated as “◯” in a case where a gloss on the surface of the mirror finished glass was maintained, as “Δ” (a triangle) in a case where the gloss was lost, and as “×” in a case where the glass was fractured.
(58) A sintered glass body was obtained by applying a compaction molding to a glass powder which is pulverized by a let mill in a hand press (1 ton/cm.sup.2), and sintering a molded body at a temperature near the softening point in atmospheric air for 2 hours. The softening and fluidizing property of the prepared low melting glass was evaluated applying various types of lasers to the sintered glass body though a transparent substrate.
(59)
(60) The size of a compact molded glass body was φ20×1 to 2 mm. A sintered glass body after sintering shrank to about 90%. The sintered glass body 8 was placed on a transparent substrate 1 and a laser 7 was caused to transfer at a velocity of 3 mm/sec from a rear side to the sintered glass body 8 under the irradiation. A slide glass was used for the transparent substrate 1. For the laser 7, a semiconductor laser at a wavelength of 405 nm, a second harmonic wave of YAG laser at 532 nm, a semiconductor laser at 630 nm, a semiconductor laser at 805 nm, and a YAG laser at 1064 nm were used.
(61) The softening and fluidizing property was evaluated as “◯” when the laser irradiated portion of the compact molded glass body 8 was fluidized, as “□” when the compact molded glass body was fluidized but crack was generated, as “Δ” when the compact molded glass body was softened, as “∇” (an inverted triangle) when the compact molded glass body was softening but cracks were generated, and as “×” when the compact molded glass body was neither fluidized nor softened. The softening and fluidizing property of the laser irradiated portion of the compact molded glass body 8 was judged under observation by an optical microscope through the transparent substrate 1.
(62) As can be seen from Examples G1 to 33 shown in Tables 1 to 3 and Comparative Examples G34 to 44 shown in Table 4, the low melting glasses in Examples G1 to 33 showed softening point T.sub.s lower than that of the low melting glasses in Comparative Examples G42 and 44, showed heat expansion coefficient smaller than that of the low melting glasses of Comparative Examples G36 to 39, 41 to 43, and 44 and, further, showed better moisture resistance than that of any of low melting glasses in the comparative examples. Further, the low melting glasses in Examples G1 to 33 showed good softening and fluidizing property by irradiation of any laser.
(63) The low melting glasses in Examples G1 to 33 contained vanadium oxide, tellurium oxide, iron oxide and phosphorous oxide, in which the content of V.sub.2O.sub.5, TeO.sub.2, Fe.sub.2O.sub.3 and P.sub.2O.sub.5 in total was 90 mass % or more in terms of oxides and they were in a relation of V.sub.2O.sub.3>TeO.sub.2>Fe.sub.2O>P.sub.2O.sub.5 (mass %). Further, one or more of tungsten oxide, molybdenum oxide, manganese oxide, zinc oxide, barium oxide, strontium oxide and calcium oxide may also be contained as glass ingredients and they were in the following relation in terms of oxides. WO.sub.3+MoO.sub.2+MnO.sub.2+ZnO+BaO+SrO+CaO≦10 mass %
(64) A particularly effective compositional range on the premise of satisfying the conditions is 35 to 50 mass % of V.sub.2O.sub.5, 20 to 35 mass % of TeO.sub.2, 10 to 20 mass % of Fe.sub.2O.sub.3, 4 to 15 mass % of P.sub.2O.sub.5, and 0 to 10 mass % of one or more of WO.sub.3, MoO.sub.3, MnO.sub.2, ZnO, SrO, BaO and CaO in total in term of oxides.
(65) Further, the low melting glasses in Examples G1 to 33 was efficiently absorbed a laser at a wavelength in the range from 400 to 1100 nm and was heated. In addition, since the softening point T.sub.s was as low as 410° C. or lower, they showed a good softening and fluidizing property. Further, since the transition point T.sub.g was as low as 350° C. or lower and the heat expansion coefficient was relatively small as 100×10.sup.−7/° C. or less, they were less cracked due to heat shocks by the laser irradiation.
EXAMPLE 2
(66) In this example, a laser sealing experiment was performed by using the low melting glass in Example G12 shown in Table 2 and a slide glass as a transparent substrate. A sealing material paste was prepared by using a powder of the low melting glass of G12 pulverized to a mean particle diameter of 3 μm or less by a jet mill, a resin binder and a solvent. Nitrocellulose was used as the resin binder and butyl carbitol acetate was used as the solvent.
(67) The sealing material paste was used and coated to the outer peripheral portion of a transparent substrate by a dispenser method as illustrated in
(68) As illustrated in
(69) For the airtightness (gas barrier property), a helium leak test was performed and the sample was evaluated as “◯” when leak did not occur and as “×” when leak occurred. Further, for the bondability, a peeling test was performed and evaluated as “◯” when the transparent substrate or the sealing material was fractured, and evaluated as “×” when peeling occurred readily from the interface between the transparent substrate and the sealing material. When the thickness of the sintered film was 20 μm or less, the airtightness and the bondability were satisfactory by using any laser. However, good airtightness and bondability could not sometimes be obtained depending on the laser used at the sintered film thickness of 30 μm. A YAG laser was used for the wavelength of 532 nm and 1064 nm and it is considered that good airtightness and bondability could be obtained since the power is higher than that of other semiconductor layers. Since the semiconductor laser is extremely inexpensive compared with the YAG laser, use of the semiconductor laser is preferred for laser sealing and the thickness of the bonded layer is preferably 20 μm or less.
(70) However, when the laser was applied from both surfaces of the transparent substrates 1 and 2, good airtightness and bondability were obtained even at the thickness of the sintered film of 30 μm. That is, in a case where the thickness of the bonded layer is large, such a method may be possibly used sufficiently as a countermeasure.
(71)
(72) In a wavelength region from 300 to 2000 nm, the transmittance was lower as the wavelength was shorter and the transmittance was lowered as the thickness of the sintering film was larger. Since low melting glasses of other examples shown in Tables 1 to 3 also have identical transmittance curves, it is apparent that an identical effect can be obtained.
EXAMPLE 3
(73) In this example, the laser sealing experiment was performed in the same manner as in Example 2 by using a polycarbonate for the transparent substrate. Since the heat resistance of the polycarbonate is lower than that of the low melting glass of G12, a semiconductor laser at a wavelength of 805 nm was used when sintering was applied previously to the transparent substrate. When the laser was used, a sintered coating film of G12 was obtained while scarcely heating the polycarbonate. In order to decrease foaming, the sealing material paste was prepared only from α-terpineol as a high viscosity solvent and the glass powder of G12 without using the resin binder.
(74) As illustrated in
EXAMPLE 4
(75) In this example, a laser sealing experiment identical with that of Example 2 was performed by using a borosilicate glass substrate having a heat expansion coefficient of 50×10.sup.−7/° C. as a transparent substrate, Example G19 shown in Table 2 as the low melting glass contained in the sealing material, and zirconium phosphotungstate (Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2), niobium oxide (Nb.sub.2O.sub.5) and β-eucryptite (LiAlSiO.sub.4) as the filler particles for decreasing the heat expansion coefficient of the sealing material.
(76) First, a sealing material paste was prepared by using a powder of the low melting glass of G19 pulverized to a mean particle diameter of 3 μm or less by a jet mill, the filler particles of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2, Nb.sub.2O.sub.5 or LiAlSiO.sub.4 with a mean particle diameter of about 5 μm, a resin binder, and a solvent. Further, the content of the filler particles was set to 15, 25, 35 and 45 parts by volume based on 100 parts by volume of the low melting glass of G19 respectively. The density of the low melting glass G19 used was 3.67 g/cm.sup.3, the density of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 was 3.80 g/cm.sup.3, the density of Nb.sub.2O.sub.5 was 4.57 g/cm.sup.3, and the density of LiAlSiO.sub.4 was 2.42 g/cm.sup.3. Further, ethyl cellulose was used as the resin binder and butyl carbitol acetate was used as the solvent. The sealing material paste was used and coated to the outer peripheral portion of the transparent substrate by the screen printing method as illustrated in
(77) As illustrated in
(78) If the filler particles were not contained in the sealing material 5, the difference of thermal expansion between the glass substrate used for the transparent substrate 1 and 2 and the Low melting glass G19 was large, cracks occurred and no satisfactory airtightness could be obtained. However, in spite of the occurrence of the cracks, the bondability was satisfactory. When the filler particles of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2, Nu.sub.2O.sub.5 or LiAlSiO.sub.4 were contained, the heat expansion coefficient as the sealing material 5 decreased and good airtightness could be obtained. This is because the difference of the thermal expansion from that of the glass substrate used as the transparent substrates 1 and 2 was decreased and occurrence of the cracks was prevented. Further, good bondability was also obtained when the content of the filler particles was up to 35 parts by weight. However, if the content of the filler particles increased to 45 parts by volume, the bondability was deteriorated although good airtightness was maintained. This is because the content of the low melting glass G19 for bonding the transparent substrates 1 and 2 decreased if the filler particles were excessive.
(79) Further, when Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 was used among the filler particles of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2, Nb.sub.2O.sub.5 and LiAlSiO.sub.4, this was dispersed most uniformly in the low melting glass G19 and showed a high bonding force as well. This is considered to be attributable to that the wettability with the low melting glass G19 is satisfactory and the density was close to that of the glass.
(80) In view of the above, it is considered that the content of the filler particles contained in the sealing material 5 is preferably 3.5 parts by volume or less based on 100 parts by volume of the low melting glass 100 in order to bond the transparent substrates 1 and 2 airtightly and firmly by the laser. In this example, Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2, Nb.sub.2O.sub.5 and LiAlSiO.sub.4 were selected and investigated as the filler particles. However, they are not restrictive but cordielite, zirconium phosphate, zirconium silicate, etc. having small heat expansion coefficient may also be used possibly.
EXAMPLE 5
(81) It was found in view of Example 4 that the use of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 was preferred among the filler particles of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2Nb.sub.2O.sub.5, and LiAlSiO.sub.4. Then, in this example, Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles that can be heated by the laser irradiation were investigated. A small amount of iron tungstate (FeWO.sub.4) and zirconium phosphate (ZrO(PO.sub.4).sub.2) were precipitated in the Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles. Precipitation of FeWO.sub.4 and ZrO(PO.sub.4).sub.2 in the Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles was confirmed by X-ray diffractometry. It was found that FeWO.sub.4 could absorb the laser and cause the Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles to generate heat. ZrO(PO.sub.4).sub.2 is an auxiliary precipitation product formed by precipitation of FeWO.sub.4 in the Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles. An experiment identical with that in Example 4 was performed by using Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles containing FeWO.sub.4 and ZrO(PO).sub.2 and the low melting glass G16 in Table 2. The content of the filler particles was set to 35 parts by volume based on 100 parts by volume of the low melting glass of G16.
(82) As a result of the investigation identical with that in Example 4 by using the Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler particles containing FeWO.sub.4 and ZrO(PO.sub.4).sub.2, the substrates were bonded more firmly than in the case of using the Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 filler alone. Further, as a result of the investigation when the transfer velocity of the laser was increased, good bondability was obtained up to a velocity of 30 mm/sec in a case of using the filler particles of this example, while the substrates could be bonded at a velocity up to 15 mm/sec in a case of using the filler particles of Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 alone. The low melting glass was heated so far upon the laser irradiation, but there may be a possibility that the heat was deprived by the filler particles. It is considered that the softening and fluidizing property of the sealing material was improved greatly by the laser irradiation and the laser transfer velocity could be increased remarkably by efficient heating of both the low melting glass and the filler particles. This can greatly contribute to the improvement of the productivity of the electronic components and decrease of thermal damages to the inside of the electronic component.
EXAMPLE 6
(83) If the distance between the transparent substrates 1 and 2 was 100 μm or more, even when the laser was applied from both surfaces by the producing method shown in Example 2, no satisfactory airtightness and bondability could be obtained since cracks occurred in the sealing material 5 or the softening and fluidizing property of the low melting glass contained in the sealing material 5 was insufficient. In view of the above in this embodiment, the transparent substrates 1 and 2 were bonded by way of a spacer 6 interposed therebetween as illustrated in
EXAMPLE 7
(84) In this example, a display having a lot of organic light emitting diode (OLED) disposed therein was manufactured and evaluated. The OLED display has a structure illustrated in
(85) In view of the above, it was found that the present invention is applicable effectively to the OLED display. It will be apparent that the invention is applicable also to electronic components such as lighting equipment in which OLED is mounted.
EXAMPLE 8
(86) In this example, a dye-sensitized solar cell containing an organic dye was manufactured and evaluated. Generally, molecules of an organic dye are formed to the surface of a number of titania (TiO.sub.2) nanoparticles in the solar cell. When the dye is irradiated with light, excited electrons are injected into TiO.sub.2 and reach an electrode while diffusing in the nanoparticles. On the other hand, electrons are injected at the counter electrode into an electrolyte to reduce iodine (I). Thus, electric power can be generated. Since the dye-sensitized solar cell does not use vacuum, low temperature process, and silicon, this is effective for cost reduction but involves a significant problem in view of the reliability. A sealing technique is the key to the improvement of the reliability. Since the organic dye and the electrolyte of law heat resistance are used, sealing has to be performed at a temperature lower than the heat resistant temperature of them and resin sealing is generally used. However, resin sealing involves a significant problem that long time reliability cannot be ensured.
(87) The present invention was trially applied to the sealing of the dye-sensitized solar cell in the same manner as in Example 7. A white board glass of high transmittance was used as the transparent substrates 1 and 2. The sealing material 5 was formed to the transparent substrate 1 by using the sealing material paste and under the sintering condition identical with those of Example 6. A cell containing a number of organic dyes, etc. was formed or disposed to the transparent substrate 2, and the outer peripheral portions of the transparent substrates 1 and 2 were bonded by laser irradiation in the same manner as in Example 7. They could be bonded firmly and the bondability was good. Further, also in the high temperature and high humidity test (saturated pressure cooker test) in the same manner as in Example 7, good airtightness was kept with no problems. In addition, the bondability after the high temperature and high humidity test was also good. Further, corrosion with iodine was not observed at the bonded portion as well. However, the electrode was corroded with iodine. In view of the above, the low melting glass according to the present invention is possibly applicable also to the coating of the electrode, etc. in addition to the sealing of the dye-sensitized solar cell.
(88) In view of the above, it was found that the present invention is applicable effectively to the dye-sensitized solar cell. Further, it is applicable also to electronic components of organic solar cells, not being restricted only to the dye-sensitized solar cell.
EXAMPLE 9
(89) In this example, a solar cell containing a lot of photoelectronic conversion elements and being bonded with a resin was manufactured and evaluated. A double-sided light receiving cell using a single crystal silicon substrate was used as the photoelectronic conversion element. The cells were connected in series by way of tab wires. Conventionally, they were bonded by an EVA sheet between two transparent substrates and fixed at ends by an aluminum frame and a resin sealing material. A white board glass of a high transmittance was generally applied for the transparent substrate. Most of subsequent accidents in the solar cells are caused by water permeating to the inside. The EVA sheet has no high gas barrier property (airtightness) and moisture gradually permeates for a long time and the moisture may possibly erode and disconnect the tab wires that connect cells, connection portions thereof, and electrodes formed to the cell. Accordingly, it is extremely important to prevent water permeation for ensuring the long time reliability of the solar cell. In this example, the white board glass was used as the transparent substrate and the EVA sheet was used as the bonding resin. Since the thickness of the both-sided light receiving cell used was about 250 μm including the thickness of the electrodes on both surfaces and the thickness of the attaching layer of the EVA sheet for both cell surfaces was about 250 μm, the substrates were bonded by way of the spacer as illustrated in
(90) In this example, while the description of this Example has been made about a solar cell using the both-sided light receiving Si cell and the EVA sheet, this is applicable generally to solar cells in which the cells and the transparent substrates are bonded and fixed by using the resin. For example, this is applicable also to the thin film solar cell.
(91) While the above descriptions have been made about the OLED display, the dye-sensitized solar cell and the Si solar cell applied with the invention, the invention is not restricted to them but is applicable generally to electronic components containing organic elements or organic materials of low heat resistance and can remarkably improve the reliability and the productivity of the electronic components.
(92) TABLE-US-00001 TABLE 1 Examples [Example] glass No. G1 G2 G3 G4 G5 G6 G7 G8 G9 G10 G11 Composition V.sub.2O.sub.5 50 50 50 50 48 47 47 47 46 46 45 (mass %) TeO.sub.2 32 30 30 21 32 30 30 23 28 23 32 Fe.sub.2O.sub.3 10 12 10 12 13 14 10 12 12 15 10 P.sub.2O.sub.5 8 8 6 10 7 9 9 10 7 13 4 WO.sub.3 4 5 3 3 3 3 MoO.sub.3 2 3 MnO.sub.2 3 ZnO 1 3 3 BaO 3 2 SrO 2 CaO Density (g/cm.sup.3) 3.59 3.57 3.72 3.45 3.65 3.60 3.62 3.48 3.59 3.46 3.68 DTA characteristic Transition point T.sub.g 263 268 257 315 265 278 274 325 292 336 285 temperature Yield point M.sub.g 280 290 276 330 284 297 293 350 310 362 305 (° C.) Softening point T.sub.s 322 334 315 373 326 341 338 389 356 397 353 Crystallization 448 441 423 475 445 448 462 472 444 485 449 temperature T.sub.cry Heat expansion coefficient (×10.sup.−7/° C.) 99 97 98 82 96 94 93 83 98 81 100 Heat expansion Transition 265 272 261 323 268 282 277 337 295 355 291 characteristic temperature T.sub.G temperature (° C.) Deformation 302 309 297 357 307 318 315 371 330 377 325 temperature A.sub.T Moisture resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ (120° C. - 100% Rh-202 kPa-3 days) Softening and 405 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ fluidizing 532 nm wavelenglh ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ property due 630 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ to laser 805 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ irradiation 1064 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘
(93) TABLE-US-00002 TABLE 2 Examples [Example] glass No. G12 G13 G14 G15 G16 G17 G18 G19 G20 G21 G22 Composition V.sub.2O.sub.5 45 45 45 45 45 45 45 44 43 43 43 (mass %) TeO.sub.2 30 30 30 30 27 25 20 29 30 30 28 Fe.sub.2O.sub.3 15 15 10 10 15 15 15 18 17 15 19 P.sub.2O.sub.5 10 7 9 7 10 10 10 9 10 12 10 WO.sub.3 3 3 3 5 2 MoO.sub.3 4 MnO.sub.2 ZnO 1 BaO 4 3 2 SrO 1 2 CaO 2 Density (g/cm.sup.3) 3.65 3.69 3.73 3.84 3.62 3.59 3.73 3.67 3.63 3.58 3.58 DTA characteristic Transition point T.sub.g 308 297 298 302 311 316 328 315 321 318 332 temperature Yield point M.sub.g 329 317 325 324 335 338 351 340 345 340 354 (° C.) Softening point T.sub.s 377 365 371 375 380 386 399 383 387 387 401 Crystallization 458 455 428 468 454 462 465 451 447 478 455 temperature T.sub.cry Heal expansion coefficient (×10.sup.−7/° C.) 93 94 99 100 88 86 97 88 90 87 87 Heat expansion Transition 315 304 305 310 318 321 331 331 326 302 355 characteristic temperature T.sub.G temperature (° C.) Deformation 357 345 347 351 359 362 378 363 367 340 377 temperature A.sub.T Moisture resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ (120° C. - 100% Rh-202 kPa-3 days) Softening and 405 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ fluidizing 532 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ property due 630 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ to laser 805 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ irradiation 1064 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘
(94) TABLE-US-00003 TABLE 3 Examples [Example] glass No. G23 G24 G25 G26 G27 G28 G29 G30 G31 G32 G33 Composition V.sub.2O.sub.5 43 42 41 40 40 40 39 38 38 37 35 (mass %) TeO.sub.2 25 27 30 35 30 25 25 30 30 33 30 Fe.sub.2O.sub.3 12 16 15 15 20 15 15 17 12 19 15 P.sub.2O.sub.5 10 10 9 4 10 10 12 15 10 11 10 WO.sub.3 4 3 3 10 5 5 MoO.sub.3 3 5 MnO.sub.2 5 ZnO 2 5 3 BaO 3 3 3 SrO 2 CaO 1 Density (g/cm.sup.3) 3.70 3.62 3.72 3.82 3.79 3.75 3.71 3.70 3.85 3.84 3.88 DTA characteristic Transition point T.sub.g 315 310 285 279 341 297 309 350 318 336 322 temperature Yield point M.sub.g 345 334 311 299 364 320 326 369 336 360 345 (° C.) Softening point T.sub.s 388 380 358 339 406 364 379 410 385 400 399 Crystallization 464 449 455 432 462 456 455 496 468 465 475 temperature T.sub.cry Heat expansion coefficient (×10.sup.−7/° C.) 99 89 88 100 86 96 92 87 93 90 91 Heat expansion Transition 321 317 289 286 349 305 316 353 320 342 326 characteristic temperature T.sub.G temperature (° C.) Deformation 362 359 337 322 386 350 358 385 362 379 368 temperature A.sub.T Moisture resistance ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ (120° C. - 100% Rh-202 kPa-3 days) Softening and 405 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ fluidizing 532 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ property due 630 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ to laser 805 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ irradiation 1064 nm wavelength ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘
(95) TABLE-US-00004 TABLE 4 Comparative examples [Example] glass No. G34 G35 G36 G37 G38 G39 G40 G41 G42 G43 G44 Composition V.sub.2O.sub.5 60 55 55 50 50 45 45 40 40 35 30 (mass %) TeO.sub.2 10 25 20 25 20 30 15 35 20 35 10 Fe.sub.2O.sub.3 10 10 10 5 10 15 5 P.sub.2O.sub.5 30 10 15 10 15 10 15 10 20 15 25 WO.sub.3 10 10 10 5 5 MoO.sub.3 3 5 MnO.sub.2 9 5 ZnO 5 5 BaO 5 2 3 5 5 5 10 SrO 2 CaO 1 Density (g/cm.sup.3) 3.10 3.38 3.42 3.55 3.64 3.88 3.71 3.96 3.77 3.94 3.65 DTA characteristic Transition point T.sub.g 315 283 278 283 305 285 315 293 343 302 354 temperature Yield point M.sub.g 336 301 298 302 324 311 340 309 370 318 380 (° C.) Softening point T.sub.s 399 345 340 348 373 353 388 358 416 364 425 Crystallization 425 442 396 487 419 >500 484 >500 >500 465 >500 temperature T.sub.cry Heat expansion coefficient (×10.sup.−7/° C.) 85 94 105 103 107 110 96 125 92 112 104 Heat expansion Transition 320 288 283 285 309 289 321 296 347 307 357 characteristic temperature T.sub.G temperature (° C.) Deformation 365 317 334 325 345 328 364 333 393 330 404 temperature A.sub.T Moisture resistance x x x Δ x x x Δ x Δ x (120° C. - 100% Rh-202 kPa-3 days) Softening and 405 nm wavelength Δ ∘ ∇ □ ∇ ∇ ∘ □ Δ □ x fluidizing 532 nm wavelength ∘ ∘ □ □ □ □ ∘ □ ∘ □ ∇ property due 630 nm wavelength x ∘ ∇ □ ∇ ∇ ∘ □ ∘ □ x to laser 805 nm wavelength x ∘ x Δ x x ∘ ∇ Δ □ x irradiation 1064 nm wavelength x ∘ x Δ x x ∘ ∇ x ∇ x
(96) TABLE-US-00005 TABLE 5 Thickness of sintered Thickness of sintered Thickness of sintered Thickness of sintered film: 5 μm film: 10 μm film: 20 μm film: 30 μm Airtightness Bondability Airtightness Bondability Airtightness Bondability Airtightness Bondability Wavelength of laser 405 nm ∘ ∘ ∘ ∘ ∘ ∘ x x irradiation 532 nm ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘ 630 nm ∘ ∘ ∘ ∘ ∘ ∘ x x 805 nm ∘ ∘ ∘ ∘ ∘ ∘ ∘ x 1064 nm ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘
(97) TABLE-US-00006 TABLE 6 15 parts by volume 25 parts by volume 35 parts by volume 45 parts by volume Filler particle Airtightness Bondability Airtightness Bondability Airtightness Bondability Airtightness Bondability Zr.sub.2(WO.sub.4)(PO.sub.4).sub.2 ∘ ∘ ∘ ∘ ∘ ∘ ∘ x Nb.sub.2O.sub.5 ∘ ∘ ∘ ∘ ∘ ∘ ∘ x LiAlSiO.sub.4 ∘ ∘ ∘ ∘ ∘ ∘ ∘ x
REFERENCE SIGNS LIST
(98) 1, 2: transparent substrate, 3: organic member, 5: sealing material, 6: spacer, 7, 7′: laser, 8: sintered glass body.