JP5651327B2 - Glass welding method - Google Patents

Description

  The present invention relates to a glass welding method for producing a glass welded body by welding glass members together.

  As a conventional glass welding method in the above technical field, a glass layer containing a laser light-absorbing pigment is baked on one glass member along the planned welding region, and then the other glass is placed on the glass member via the glass layer. A method is known in which one glass member and the other glass member are welded by overlapping the members and irradiating a laser beam along the planned welding region (see, for example, Patent Document 1).

JP-T-2006-524419

  However, when glass members are welded together by laser light irradiation, cracks may occur in the glass members.

  Then, this invention is made | formed in view of such a situation, and it aims at providing the glass welding method which can manufacture a reliable glass welded body.

  As a result of intensive studies in order to achieve the above object, the present inventor, as shown in FIG. 11, shows that the glass member is cracked in the welding of the glass members by the irradiation of the laser beam. When the temperature of the glass layer exceeded the melting point Tm at the time of irradiation, it was ascertained that this was due to the rapid increase in the laser light absorption rate of the glass layer. That is, in the glass layer disposed between the glass members, light scattering exceeding the absorption characteristics of the laser light absorbing pigment occurs due to the particle property of the glass frit and the like, and the laser light absorption rate is low. (For example, it looks whitish under visible light). Therefore, as shown in FIG. 12, when the laser beam is irradiated with the laser power P such that the temperature of the glass layer is higher than the melting point Tm and lower than the crystallization temperature Tc, particles are melted due to melting of the glass frit. For example, the absorption characteristics of the laser light-absorbing pigment appear remarkably, and the laser light absorption rate of the glass layer increases rapidly (for example, it looks blackish or greenish under visible light). As a result, absorption of laser light more than expected occurs in the glass layer, and cracks occur in the glass member due to heat shock due to excessive heat input.

  The present inventor has further studied based on this finding and has completed the present invention. That is, the glass welding method according to the present invention is a glass welding method for manufacturing a glass welded body by welding a first glass member and a second glass member, and includes a glass containing a laser light absorbing material and glass powder. A first heat input amount in a state in which the layer is disposed on the first glass member so as to be along the planned welding region, and the second glass member is superimposed on the first glass member via the glass layer. When the glass layer is melted by irradiating the first laser beam having a predetermined welding area along the region to be welded, and the melting rate of the glass layer in the direction intersecting the traveling direction of the first laser beam exceeds a predetermined value By switching from the first heat input amount to the second heat input amount smaller than the first heat input amount, the glass layer is irradiated by irradiating the first laser beam having the second heat input amount along the planned welding region. Melted first glass member Characterized in that it comprises a step of welding the second glass member.

  In this glass welding method, when the glass layer is melted by irradiating the first laser beam along the planned welding region, the first laser beam having the first heat input amount is irradiated along the planned welding region. When the melting rate of the glass layer in the direction crossing the traveling direction of the first laser beam exceeds a predetermined value, the heat input amount is switched to reduce the second heat input amount smaller than the first heat input amount. By irradiating the first laser beam having a heat input amount along the planned welding region, the glass layer is melted, and the first glass member and the second glass member are welded. At the time of melting of the glass layer, if the melting rate of the glass layer exceeds a predetermined value, the laser light absorption rate of the glass layer rapidly increases, but thereafter, the glass layer has a second heat input amount smaller than the first heat input amount. Since the first laser beam is irradiated, the glass layer is prevented from being in an excessive heat input state. By switching the amount of heat input, even if the first glass member and the second glass member are welded by the irradiation of the first laser beam, the glass member is damaged, for example, a crack occurs in the glass member. Can be prevented. Therefore, according to this glass welding method, it is possible to prevent a crack from occurring in the first glass member and the second glass member, and to manufacture a highly reliable glass welded body. The “heat input amount” is an energy density that the first laser beam has in its irradiation region. The “melting rate of the glass layer” is the ratio of the “width of the molten portion of the glass layer” to the “total width of the glass layer” in the direction intersecting the traveling direction of the first laser beam.

  In the glass welding method according to the present invention, it is preferable to switch from the first heat input amount to the second heat input amount by reducing the irradiation power of the first laser light. In this case, since the heat input amount is switched due to a decrease in irradiation power, it is possible to surely switch from the first heat input amount to the second heat input amount.

  In the glass welding method according to the present invention, it is preferable to switch from the first heat input amount to the second heat input amount by increasing the traveling speed of the first laser beam on the glass layer. In this case, since the heat input amount is switched by increasing the traveling speed of the first laser beam, it is possible to surely switch from the first heat input amount to the second heat input amount. Moreover, since the switching is performed by increasing the traveling speed, it is possible to shorten the time required for fixing the glass layer. The “advance speed of the first laser light relative to the glass layer” means the relative advance speed of the first laser light, and when the first laser light is fixed and the glass layer moves, glass is moved. The case where the first laser beam moves while the layer is fixed includes the case where each of the first laser beam and the glass layer moves.

  In the glass welding method according to the present invention, it is preferable to switch from the first heat input amount to the second heat input amount when a predetermined time has elapsed from the start of irradiation with the first laser beam. In this case, it is possible to easily switch from the first heat input amount to the second heat input amount by a simple method of controlling the predetermined time obtained in advance. In addition, in the case of glass layers having the same configuration, if the irradiation conditions of the first laser beam are the same, the predetermined time can be made substantially the same, so that a plurality of glass layers having the same configuration are melted continuously or simultaneously. Can be easily performed, and manufacturing efficiency can be improved.

  In the glass welding method according to the present invention, it is preferable to switch from the first heat input to the second heat input when the intensity of the heat radiation emitted from the glass layer rises to a predetermined value. In this case, it is possible to accurately switch the amount of heat input by detecting the intensity of heat radiation having such a relationship that the glass layer gradually increases as the melting rate of the glass layer increases.

  In the glass welding method according to the present invention, when the intensity of the reflected light of the first laser beam reflected by the glass layer is reduced to a predetermined value, the first heat input amount is switched to the second heat input amount. preferable. In this case, it is possible to accurately switch the amount of heat input by detecting the intensity of reflected light having such a relationship that it gradually decreases as the melting rate of the glass layer increases.

  According to the present invention, a highly reliable glass welded body can be manufactured.

It is a perspective view of the glass welded body manufactured by one Embodiment of the glass welding method which concerns on this invention. It is a perspective view for demonstrating the glass welding method for manufacturing the glass welded body of FIG. It is a perspective view for demonstrating the glass welding method for manufacturing the glass welded body of FIG. It is sectional drawing for demonstrating the glass welding method for manufacturing the glass welded body of FIG. It is sectional drawing for demonstrating the glass welding method for manufacturing the glass welded body of FIG. It is a top view for demonstrating the glass welding method for manufacturing the glass welded body of FIG. It is a figure which shows the temperature distribution in laser irradiation. It is a figure which shows the switching timing of the irradiation conditions of a laser beam. It is a figure which shows another switching timing of the irradiation conditions of a laser beam. It is a figure which shows another switching timing of the irradiation conditions of a laser beam. It is a graph which shows the relationship between the temperature of a glass layer, and a laser beam absorptance. It is a graph which shows the relationship between a laser power and the temperature of a glass layer.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a perspective view of a glass welded body manufactured by an embodiment of a glass welding method according to the present invention. As shown in FIG. 1, the glass welded body 1 includes a glass member (first glass member) 4 and a glass member (second glass member) through a glass layer 3 formed along the planned welding region R. ) 5 is welded. The glass members 4 and 5 are, for example, rectangular plate-shaped members having a thickness of 0.7 mm made of alkali-free glass, and the welding planned region R is set in a rectangular ring shape along the outer edges of the glass members 4 and 5. Yes. The glass layer 3 is made of, for example, low-melting glass (vanadium phosphate glass, lead borate glass, etc.), and is formed in a rectangular ring shape along the planned welding region R.

  Next, the glass welding method for manufacturing the glass welded body 1 mentioned above is demonstrated.

  First, as shown in FIG. 2, a paste layer 6 is formed on the surface 4 a of the glass member 4 along the planned welding region R by applying a frit paste by a dispenser, screen printing, or the like. The frit paste is, for example, a powdery glass frit (glass powder) 2 made of low-melting glass (vanadium phosphate glass, lead borate glass, etc.), or a laser light absorbing pigment (laser) that is an inorganic pigment such as iron oxide. A light absorbing material), an organic solvent such as amyl acetate, and a binder that is a resin component (such as acrylic) that is thermally decomposed at a temperature lower than the softening point of glass. The frit paste may be obtained by kneading a glass frit (glass powder) obtained by powdering a low-melting glass to which a laser light absorbing pigment (laser light absorbing material) is added in advance, an organic solvent, and a binder. That is, the paste layer 6 includes the glass frit 2, the laser light absorbing pigment, the organic solvent, and the binder.

  Subsequently, the paste layer 6 is dried to remove the organic solvent, and the paste layer 6 is heated to remove the binder, whereby the glass layer 3 is formed on the surface 4a of the glass member 4 along the planned welding region R. Secure. In addition, the glass layer 3 fixed to the surface 4a of the glass member 4 is in a state in which light scattering exceeding the absorption characteristics of the laser light absorbing pigment occurs due to the particle property of the glass frit 2 and the laser light absorption rate is low. (For example, it looks whitish under visible light).

  Subsequently, as shown in FIG. 3, the glass member 5 is superposed on the glass member 4 to which the glass layer 3 is fixed via the glass layer 3. Then, as shown in FIGS. 4 to 6, the focused spot is aligned with the irradiation start position A in the planned welding region R of the glass layer 3, and irradiation with the laser beam (first laser beam) L <b> 1 is started. Irradiation is advanced along the planned welding area R in the direction indicated by the arrow in the figure.

  By the way, as shown in FIG. 7, the laser beam L1 has a temperature distribution in which the temperature in the central portion in the width direction (the direction substantially orthogonal to the traveling direction of the laser beam L1) is high and the temperature decreases toward both ends. doing. For this reason, as shown in FIG. 6, the melting rate of the glass layer 3 (the ratio of the width of the melted portion of the glass layer 3 to the total width of the glass layer 3 in the direction substantially orthogonal to the traveling direction of the laser beam L1). There is a predetermined distance from the irradiation start position A, which is substantially zero, to the stable region start position B where the melting rate gradually increases and becomes a stable region where the melting rate is close to 100%, and from the irradiation start position A to the stable region start position. Up to B, the glass layer 3 is an unstable region where the melting of the glass layer 3 is performed in part in the width direction.

In this unstable region, since the glass layer 3 is not melted over the entire width direction, the laser light absorption rate is not completely increased. Therefore, as shown in FIG. 8, the laser beam L1 is a strong irradiation condition that causes crystallization when irradiated to the glass layer 3 in the stable region, for example, the first irradiation power of the laser beam L1 is 10 W Irradiation starts with the amount of heat input. The amount of heat input can be expressed by the following formula (1). In this embodiment, since the traveling speed and the spot diameter are constant, the amount of heat input changes depending on the irradiation power. Yes.
Heat input (J / mm ² ) = Power density (J · S / mm ² ) ÷ Progress speed (S) (1)

  Thereafter, when the glass layer 3 reaches a stable region starting position B and becomes a stable region in which the glass layer 3 is melted over the entire width direction, the temperature of the glass layer 3 becomes equal to or higher than the melting point Tm in the width direction. Thus, the absorption characteristic of the laser light absorbing pigment appears remarkably, the laser light absorption rate of the glass layer 3 increases rapidly over the entire width direction, and the melting rate approaches 100% (for example, dark or green under visible light). Looks like). Thereby, absorption of the laser beam L1 more than expected occurs in the glass layer 3, and heat input to the glass layer 3 becomes excessive.

  Therefore, as shown in FIG. 8, after a predetermined time X when the melting rate of the glass layer 3 becomes nearly 100% (or immediately before), that is, the glass layer 3 exceeds the melting point Tm in the entire width direction, and the laser beam is emitted. Immediately after the absorption rate suddenly increases, switching is performed to lower the irradiation power of the laser beam L1 from the irradiation power 10W to the irradiation power 8W, and the second heat input amount of the irradiation power 8W from the first heat input amount of the irradiation power 10W. The amount of heat input is switched. In the present embodiment, the predetermined time X is obtained in advance for each configuration of the glass layer 3, and from the first heat input to the second heat input by a simple method of controlling the predetermined time X obtained in advance. Switching. Further, in the case of glass layers having the same configuration, the melting degree is substantially the same for the same heat input, so that the predetermined time X can be made substantially the same if the irradiation conditions of the laser light L1 are the same.

  Thereafter, laser irradiation is performed with an irradiation power of 8 W, which is the second heat input amount, and irradiation to the glass layer 3 with the laser light L1 is continued until the irradiation start position A is returned along the planned welding region R, and the glass member 4 and The welding with the glass member 5 is terminated. Thereby, the glass layer 3 and its peripheral part (surface 4a, 5a part of the glass members 4 and 5) fuse | melt and resolidify, and the glass member 4 and the glass member 5 are welded (in welding, the glass layer 3 May melt and the glass members 4 and 5 may not melt), and the glass welded body 1 is manufactured. If necessary, the laser irradiation may be overlapped so that the unstable region is re-irradiated with the laser beam L1 to be a stable region.

  By performing such control of switching the amount of heat input and welding the glass member 4 and the glass member 5, overheating of the glass layer 3 is suppressed and generation of heat cracks in the glass members 4 and 5 is prevented. . In addition, the glass layer 3 after the welding is brought into a state in which the absorption property of the laser light absorbing pigment is remarkably exhibited and the laser light absorption rate is high (for example, visible) due to the collapse of the particle property due to the melting of the glass frit 2. It looks blackish or greenish under the light).

  As described above, in the glass welding method for manufacturing the glass welded body 1, when the glass layer 3 is melted by irradiating the laser beam L <b> 1 along the planned welding region R, the first heat input amount is provided. The amount of heat input when the glass layer 3 is melted by irradiating the laser beam L1 along the planned welding region R and the melting rate of the glass layer 3 in the direction substantially perpendicular to the traveling direction of the laser beam L1 becomes close to 100%. Are switched, and the glass layer 3 is melted by irradiating the laser beam L1 having the second heat input amount smaller than the first heat input amount along the planned welding region R, and the glass member 4 and the glass member 5 To weld. When the glass layer 3 is melted, if the melting rate of the glass layer 3 is close to 100%, the laser light absorption rate of the glass layer 3 is rapidly increased. Thereafter, the second input less than the first heat input amount is obtained. Since the laser beam L1 having a heat quantity is irradiated, the glass layer 3 is prevented from being in an excessive heat input state. With such switching of the heat input amount, even if the glass member 4 and the glass member 5 are welded by the irradiation of the laser beam L1, the glass members 4 and 5 are damaged, for example, cracks are generated in the glass members 4 and 5. Can be prevented. Therefore, according to this glass welding method, it becomes possible to prevent the glass members 4 and 5 from being damaged and to manufacture the highly reliable glass welded body 1.

  In the glass welding method described above, the first heat input amount is switched to the second heat input amount by reducing the irradiation power of the laser light L1. Since the amount of heat input is switched by such a decrease in irradiation power, it is possible to reliably switch from the first heat input amount to the second heat input amount.

  Further, in the glass welding method described above, the melting rate is close to 100% when a predetermined time X has elapsed from the start of irradiation with the laser light L1, and the first heat input amount is switched to the second heat input amount. For this reason, it is possible to easily switch from the first heat input amount to the second heat input amount by a simple method such as controlling the predetermined time X at which the melting rate is nearly 100%, which is obtained in advance. In addition, in the case of the glass layer having the same configuration, if the irradiation conditions of the laser beam L1 are the same, the predetermined time X can be made substantially the same, so that a plurality of glass layers 3 having the same configuration are melted continuously or simultaneously. Therefore, the manufacturing efficiency when manufacturing the plurality of glass welded bodies 1 can be greatly improved.

  By the way, in the organic EL package or the like, since the container itself is small, the glass members 4 and 5 that are made thinner are used. Therefore, the material of the glass members 4 and 5 should be less likely to be cracked. Low expansion glass is often selected. At this time, in order to match the linear expansion coefficient of the glass layer 3 with the linear expansion coefficient of the glass members 4 and 5 (that is, to lower the linear expansion coefficient of the glass layer 3), a filler made of ceramics or the like is added to the glass layer 3. In a large amount. If the glass layer 3 contains a large amount of filler, the laser light absorption rate of the glass layer 3 will change much more before and after the irradiation with the laser light L1. Therefore, the glass welding method described above is particularly effective when low expansion glass is selected as the material of the glass members 4 and 5.

  The present invention is not limited to the embodiment described above.

  For example, in the above embodiment, the melting rate becomes nearly 100% when the predetermined time X has elapsed from the irradiation start position A of the laser beam L1, and the first heat input amount is switched to the second heat input amount. As shown in FIG. 9, when the intensity of the heat radiation emitted from the glass layer 3 rises to a predetermined value Q, the first heat input amount may be switched to the second heat input amount. In this case, it is possible to accurately switch the amount of heat input by detecting the intensity of heat radiation having such a relationship that the glass layer 3 gradually increases as the melting rate of the glass layer 3 increases. Further, as shown in FIG. 10, when the intensity of the reflected light of the laser light L1 reflected by the glass layer 3 decreases to a predetermined value P, the first heat input amount is switched to the second heat input amount. May be. In this case, it is possible to accurately switch the amount of heat input by detecting the intensity of reflected light having such a relationship that it gradually decreases as the melting rate of the glass layer 3 increases.

  Further, in the above embodiment, the amount of heat input to the glass layer 3 is controlled by changing the irradiation power of the laser beam L1, but as shown in the above formula (1), the laser beam L1 The amount of heat input to the glass layer 3 may be switched by increasing the relative irradiation speed of the laser light L1 (that is, the traveling speed of the laser light L1 relative to the glass layer 3) while keeping the irradiation power constant. . In this case, since the heat input amount is switched by increasing the traveling speed of the laser light L1, it is possible to surely switch from the first heat input amount to the second heat input amount. Moreover, since the switching is performed by increasing the traveling speed, the time required for welding the glass member 4 and the glass member 5 can be shortened. Note that when the heat input is switched by increasing the traveling speed, the speed acceleration process is often included, so the timing at which the switching should be performed (when the predetermined time X has elapsed, or when the heat radiation light or reflected light is changed). It is preferable from the viewpoint of inhibiting crystallization of the glass layer 3 that the switching control of the advancing speed is started before the strength reaches a predetermined value, and the switching is completed at the timing when the switching should actually be performed.

  Moreover, in the said embodiment, although the laser beam L1 is made to advance with respect to the fixed glass members 4 and 5, the laser beam L1 should just advance relatively with respect to each glass member 4 and 5. FIG. The glass members 4 and 5 may be moved while the laser beam L1 is fixed, or the glass members 4 and 5 and the laser beam L1 may be moved.

  In the above embodiment, the heat input is switched when the melting rate is a predetermined value such as 100%. However, if the glass layer 3 is appropriately melted, for example, the melting rate is 90%. At this time, the amount of heat input may be switched to reliably suppress crystallization of the glass layer 3. If the heat input amount is switched while the melting rate is low, the absorption rate of the laser light after the switching becomes insufficient, and it may not be possible to maintain the melting treatment of the glass layer. The predetermined value of the melting rate for carrying out is preferably 80%.

  The irradiation with the laser beam L1 may be performed from the glass member 4 side or from the opposite side of the glass member 4.

  DESCRIPTION OF SYMBOLS 1 ... Glass welded body, 2 ... Glass frit (glass powder), 3 ... Glass layer, 4 ... Glass member (1st glass member), 5 ... Glass member (2nd glass member), A ... Irradiation start position, B: Stable region start position, R: Planned welding region, L1: Laser beam (first laser beam).

Claims (6)

A glass welding method for producing a glass welded body by welding a first glass member and a second glass member,
A step of arranging a glass layer containing a laser light absorbing material and glass powder on the first glass member so as to follow the planned welding region,
Irradiating a first laser beam having a first heat input amount along the planned welding region in a state where the second glass member is superimposed on the first glass member via the glass layer. When the melting rate of the glass layer in a direction intersecting the traveling direction of the first laser beam exceeds a predetermined value, the first heat input amount is changed from the first heat input amount. The glass layer is melted by irradiating the first laser beam having the second heat input amount along the planned welding region by switching to a smaller second heat input amount. And a step of welding the member and the second glass member.   The glass welding method according to claim 1, wherein the first heat input amount is switched to the second heat input amount by reducing the irradiation power of the first laser light.   The glass welding method according to claim 1, wherein the first heat input amount is switched to the second heat input amount by increasing a traveling speed of the first laser light with respect to the glass layer.   2. The glass welding method according to claim 1, wherein the first heat input is switched to the second heat input when a predetermined time has elapsed from the start of irradiation of the first laser light.   2. The glass welding method according to claim 1, wherein when the intensity of heat radiation light emitted from the glass layer increases to a predetermined value, the first heat input amount is switched to the second heat input amount.   The first heat input amount is switched to the second heat input amount when the intensity of the reflected light of the first laser light reflected by the glass layer decreases to a predetermined value. The glass welding method as described.

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