Patent Description:
Patent Literature <NUM> discloses a glass panel unit. The glass panel unit of Patent Literature <NUM> includes a first glass panel, a second glass panel, a frame-shaped seal arranged between the first glass panel and the second glass panel to bond the first and second glass panels hermetically, and a gas adsorbing device. The gas adsorbing device includes a first electrode, a second electrode, and a gas adsorbing portion.

The first electrode has a first inside portion located inside a vacuum space surrounded with the first and second glass panels and the seal, and a first outside portion located outside the vacuum space. The second electrode has a second inside portion located inside the vacuum space and a second outside portion located outside the vacuum space. The gas adsorbing portion has a gas adsorbent including a getter and is connected between the first inside portion and the second inside portion.

In the glass panel unit of Patent Literature <NUM>, the first outside portion and the second outside portion protrude from an end surface of the glass panel unit. Therefore, if an external terminal is connected to the first and second outside portions protruding from the end surface of the glass panel unit, the terminal and the glass panel unit are easily movable relative to each other, thus making a connecting portion between the first and second outside portions and the terminal disconnected easily. Patent Literature <NUM> describes an insulating glass element.

An object of the present disclosure to provide a glass panel unit that reduces the chances of an electric wire extended being disconnected.

A glass panel unit according to the present invention includes a first panel, a second panel, a seal, a connecting void, and an electric wire. The first panel includes a first glass pane. The second panel includes a second glass pane and is arranged to face the first panel. The seal has a frame shape and hermetically bonds respective peripheral edge portions of the first panel and the second panel to create an internal space between the first panel and the second panel. The connecting void is provided for a portion of at least one of the first panel and the second panel. The electric wire is extended from the internal space to the connecting void by passing through the seal. The connecting void is at least one through hole provided through at least one of the first panel and the second panel. The internal space includes a first space to be a hermetically sealed space and a second space to be exhaust space. The seal includes a part which has a frame shape and separates the first space from the external environment and a boundary wall that separates the first space from the second space. The through hole being provided for a portion facing the second space of at least one of the first panel and the second panel. The electric wire being extended from the first space to the through hole by passing through the seal.

Embodiments of a glass panel unit according to the present disclosure will now be described. Note that the embodiments to be described below are only exemplary ones of various embodiments of the present disclosure and should not be construed as limiting.

<FIG> and <FIG> illustrate a (final product of) glass panel unit <NUM> according to a first embodiment. The glass panel unit <NUM> according to the first embodiment is a "vacuum-insulated glazing (or glass) (VIG) unit. " The VIG unit is a type of multi-pane glazing unit including at least one pair of glass panels and having an evacuated space (or a vacuum space) between the pair of glass panels.

The glass panel unit <NUM> includes a first panel <NUM>, a second panel <NUM>, a seal <NUM>, boundary walls <NUM>, an evacuated space <NUM>, and electric wires <NUM>. In the first embodiment, the glass panel unit <NUM> further includes a gas adsorbent <NUM> and a plurality of the pillars <NUM>.

The seal <NUM> has a frame shape and hermetically bonds respective peripheral edge portions of the first panel <NUM> and the second panel <NUM> to create an internal space <NUM> (including the evacuated space <NUM>) between the first panel <NUM> and the second panel <NUM>.

The boundary walls <NUM> hermetically bond the first panel <NUM> and the second panel <NUM> together to partition the internal space <NUM> into a first space <NUM> that is the hermetically sealed evacuated space <NUM> and second spaces <NUM>, which are spatially separated from the first space <NUM>.

The first panel <NUM> has first through holes <NUM> provided through portions, corresponding to the second spaces <NUM>, of the first panel <NUM>. The first through holes <NUM> serve as connecting voids. The second panel <NUM> has second through holes <NUM> provided through portions, corresponding to the second spaces <NUM> and facing the first through holes <NUM>, of the second panel <NUM>. In the first embodiment, the boundary walls <NUM> surround the first through holes <NUM> and the second through holes <NUM> when viewed in the direction in which the first panel <NUM> and the second panel <NUM> face each other.

The electric wires <NUM> are extended from the internal space <NUM> to the connecting voids (first through holes <NUM>) by passing through the seal <NUM>.

The (final product of the) glass panel unit <NUM> is obtained by subjecting an assembly <NUM> shown in <FIG> and <FIG> to a predetermined process. The predetermined process will be outlined later.

The assembly <NUM> includes the first panel <NUM>, the second panel <NUM>, a first part <NUM> of a hot glue, the internal space <NUM>, second parts <NUM> of the hot glue, an exhaust path <NUM> that allows the first space and one of the second spaces to communicate with each other, an exhaust port <NUM>, the gas adsorbent <NUM>, and the plurality of pillars <NUM>.

The first panel <NUM> includes a first glass pane <NUM> that defines a planar shape of the first panel <NUM> and a coating <NUM>.

The first glass pane <NUM> is a rectangular flat plate and has a first surface (i.e., the lower surface in <FIG>) and a second surface (i.e., the upper surface in <FIG>), which are provided on both ends in a thickness direction to be parallel to each other. The first and second surfaces of the first glass pane <NUM> are both flat surfaces. Examples of materials for the first glass pane <NUM> include soda lime glass, high strain point glass, chemically tempered glass, alkali-free glass, quartz glass, Neoceram, and thermally tempered glass.

The coating <NUM> is formed on the first surface of the first glass pane <NUM>. The coating <NUM> may be an infrared reflective film, for example. The coating <NUM> has electrical conductivity. Note that the coating <NUM> does not have to be an infrared reflective film but may also be a film with desired physical properties. Optionally, the first panel <NUM> may consist of the first glass pane <NUM> alone. In short, the first panel <NUM> includes the first glass pane <NUM> to say the least.

The second panel <NUM> includes a second glass pane <NUM> that defines the planar shape of the second panel <NUM>. The second glass pane <NUM> is a rectangular flat plate and has a first surface (i.e., the upper surface in <FIG>) and a second surface (i.e., the lower surface in <FIG>), which are provided on both ends in the thickness direction to be parallel to each other. The first and second surfaces of the second glass pane <NUM> are both flat surfaces.

The second glass pane <NUM> may have the same planar shape and planar dimensions as the first glass pane <NUM>. That is to say, the second panel <NUM> has the same planar shape as the first panel <NUM>. In addition, the second glass pane <NUM> has the same thickness as the first glass pane <NUM>. Examples of materials for the second glass pane <NUM> include soda lime glass, high strain point glass, chemically tempered glass, alkali-free glass, quartz glass, Neoceram, and thermally tempered glass.

The second panel <NUM> consists of the second glass pane <NUM> only. That is to say, the second glass pane <NUM> is the second panel <NUM> itself. Optionally, the second panel <NUM> may have a coating on either surface thereof. The coating is a film having desired physical properties such as an infrared reflective film. In that case, the second panel <NUM> is made up of the second glass pane <NUM> and the coating. In short, the second panel <NUM> includes the second glass pane <NUM> to say the least.

The second panel <NUM> is arranged to face the first panel <NUM>. Specifically, the first panel <NUM> and the second panel <NUM> are arranged such that the first surface of the first glass pane <NUM> and the first surface of the second glass pane <NUM> face each other and are parallel to each other.

The first part <NUM> of the hot glue is arranged between the first panel <NUM> and the second panel <NUM> to hermetically bond the first panel <NUM> and the second panel <NUM> together as shown in <FIG>. The first part <NUM> is a part that will serve as the seal <NUM>. In this manner, an internal space <NUM> surrounded with the first part <NUM>, the first panel <NUM>, and the second panel <NUM> is formed.

The first part <NUM> is formed of a hot glue (i.e., a first hot glue having a first softening point). The first hot glue may be a glass frit, for example. The glass frit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include bismuth-based glass frits, lead-based glass frits, and vanadium-based glass frits.

The first part <NUM> is arranged to form a rectangular frame shape in a plan view as shown in <FIG>. When viewed in plan, the dimensions of the first part <NUM> are smaller than those of the first glass pane <NUM> or the second glass pane <NUM>. The first part <NUM> is formed along the outer periphery of the upper surface of the second panel <NUM> (i.e., the first surface of the second glass pane <NUM>). That is to say, the first part <NUM> is formed to surround almost the entire area on the second panel <NUM> (i.e., the entire area of the first surface of the second glass pane <NUM>).

The first panel <NUM> and the second panel <NUM> are hermetically bonded together via the first part <NUM> by once melting the first hot glue of the first part <NUM> at a predetermined temperature (first melting temperature) Tm1, which is equal to or higher than the first softening point.

The second parts <NUM> of the hot glue are arranged in the internal space <NUM>. The second parts <NUM> are partitions for partitioning the internal space <NUM> into a first space <NUM> to be a hermetically sealed space (i.e., a space to define an evacuated space <NUM> by being hermetically sealed when the glass panel unit <NUM> is completed) and second spaces <NUM>, one of which will be an exhaust space (i.e., a space communicating with the exhaust port <NUM>). The second parts <NUM> are parts that will serve as the boundary walls <NUM>. The second parts <NUM> are formed such that the first space <NUM> is larger than any of the second spaces <NUM>.

The second parts <NUM> are formed of a hot glue (i.e., a second hot glue having a second softening point). The second hot glue may be a glass frit, for example. The glass frit may be a low-melting glass frit, for example. Examples of the low-melting glass frits include bismuth-based glass frits, lead-based glass frits, and vanadium-based glass frits. The second hot glue is the same as the first hot glue. The second softening point is equal to the first softening point.

The exhaust port <NUM> is a hole that allows one of the second spaces <NUM> to communicate with the external environment. The exhaust port <NUM> is used to exhaust a gas from the first space <NUM> via the second space <NUM> and the exhaust path <NUM>. The exhaust port <NUM> is provided through the second panel <NUM> to allow the second space <NUM> to communicate with the external environment. Specifically, the exhaust port <NUM> is located at a corner portion of the second panel <NUM>. Note that although the exhaust port <NUM> is provided through the second panel <NUM> in the first embodiment, the exhaust port <NUM> may be provided through the first panel <NUM>. In the first embodiment, a second through hole <NUM> to be described later also serves as the exhaust port <NUM>.

The gas adsorbent <NUM> is arranged in the first space <NUM>. Specifically, the gas adsorbent <NUM> has an elongate shape and provided at a longitudinal end of the second panel <NUM> so as to extend along a shorter side of the second panel <NUM>. That is to say, the gas adsorbent <NUM> is arranged at an end of the first space <NUM> (evacuated space <NUM>). This may make the gas adsorbent <NUM> much less conspicuous. In addition, this also reduces the chances of the gas adsorbent <NUM> obstructing exhausting the gas from the first space <NUM>.

The gas adsorbent <NUM> is used to adsorb unnecessary gases (such as a residual gas). The unnecessary gases are released from the first part <NUM> and the second parts <NUM> when the first part <NUM> and the second parts <NUM> are heated to the first melting temperature Tm <NUM>, for example.

The gas adsorbent <NUM> includes a getter. The getter is a material having the property of adsorbing molecules, of which the size is smaller than a predetermined size. The getter may be an evaporative getter, for example. The evaporative getter has the property of releasing the adsorbed molecules when heated to a predetermined temperature (activation temperature) or more. This allows, even if the adsorption ability of the evaporative getter has declined once, the evaporative getter to recover its adsorption ability by heating the evaporative getter to the activation temperature or more. The evaporative getter may be either zeolite or an ion-exchanged zeolite (e.g., zeolite exchanged with copper ions).

The gas adsorbent <NUM> includes a powder of this getter. Specifically, the gas adsorbent <NUM> is formed by applying a solution in which a powder of the getter is dispersed. This allows the gas adsorbent <NUM> to have a reduced size. In that case, the gas adsorbent <NUM> may still be arranged even in a narrow, evacuated space <NUM>.

The plurality of pillars <NUM> is used to maintain a predetermined gap distance between the first panel <NUM> and the second panel <NUM>. That is to say, the plurality of pillars <NUM> serves as a spacer for maintaining a desired gap distance between the first panel <NUM> and the second panel <NUM>.

The plurality of pillars <NUM> are placed in the first space <NUM>. Specifically, the pillars <NUM> are placed at respective intersections of a rectangular (or square) grid. The plurality of pillars <NUM> may have an interval of <NUM>, for example. However, this is only an example and should not be construed as limiting. Rather, the size, number, spacing, and placement pattern of the pillars <NUM> may be selected appropriately.

The pillars <NUM> are made of a transparent material in this embodiment. Alternatively, the pillars <NUM> may also be made of an opaque material as long as the size of the pillars <NUM> is sufficiently small. The material for the pillars <NUM> is selected such that the pillars <NUM> will not be deformed in the internal space forming step (to be described later). The material for the pillars <NUM> is selected so as to allow the pillars <NUM> to have a softening point (softening temperature) higher than the first softening point of the first hot glue and the second softening point of the second hot glue, for example.

In such an assembly <NUM>, the first space <NUM> is turned into the evacuated space <NUM> by exhausting, at a predetermined temperature (exhaust temperature) Te, the gas from the first space <NUM> through a path made up of the exhaust path <NUM>, one of the second spaces <NUM>, and the exhaust port <NUM> and allowing the gas to be exhausted into the external environment. The exhaust temperature Te is set at a temperature higher than the getter activation temperature of the gas adsorbent <NUM>. This enables not only exhausting the gas from the first space <NUM> but also letting the getter recover its adsorption ability at a time.

In addition, as shown in <FIG>, the evacuated space <NUM> is surrounded with the seal <NUM> and the boundary walls <NUM> by deforming the second parts <NUM> (see <FIG>) and thereby forming the boundary wall <NUM> that close the exhaust path <NUM>. That is to say, in the first embodiment, the seal <NUM> defines the outer peripheral edges of the evacuated space <NUM> and the boundary walls <NUM> define the inner peripheral edges of the evacuated space <NUM>. The second parts <NUM> include the second hot glue. Therefore, if the second hot glue is once melted by locally heating the second parts <NUM>, the second parts <NUM> may be deformed to form the boundary walls <NUM>.

The second parts <NUM> are deformed to close the exhaust path <NUM> as shown in <FIG>. The boundary walls <NUM> that have been formed by deforming the second parts <NUM> in this manner spatially separate the evacuated space <NUM> from the second spaces <NUM>. The seal <NUM> surrounding the evacuated space <NUM> is made up of the boundary walls <NUM> and a part <NUM> other than the boundary walls <NUM>.

The (final product of the) glass panel unit <NUM> thus obtained includes the first panel <NUM>, the second panel <NUM>, the seal <NUM>, the evacuated space <NUM>, the second space <NUM>, the gas adsorbent <NUM>, and the plurality of pillars <NUM> as shown in <FIG>.

The evacuated space <NUM> is formed by exhausting the gas from the first space <NUM> through one of the second spaces <NUM> and the exhaust port <NUM> as described above. In other words, the evacuated space <NUM> is the first space <NUM>, of which the degree of vacuum is equal to or less than a predetermined value. The predetermined value may be <NUM> Pa, for example. The evacuated space <NUM> is perfectly hermetically sealed by the first panel <NUM>, the second panel <NUM>, and the seal <NUM>, and therefore, is separated from the second spaces <NUM> and the exhaust port <NUM>.

The seal <NUM> not only surrounds the evacuated space <NUM> entirely but also hermetically bonds the first panel <NUM> and the second panel <NUM> together. The seal <NUM> includes the part <NUM> which has a frame shape and (spatially) separates the first space <NUM> from the external environment and the boundary walls <NUM> that separate the first space <NUM> from the second spaces <NUM>. The boundary walls <NUM> are formed by deforming the second parts <NUM>.

Next, a method for manufacturing the glass panel unit <NUM> according to the first embodiment will be described with reference to <FIG>.

A method for manufacturing the glass panel unit <NUM> according to the first embodiment includes at least a glue arrangement step, a glass composite producing step, an internal space forming step, an evacuation step, and an evacuated space forming step. The method may further include other process steps, which are optional ones. This method will now be described step by step sequentially.

In the first embodiment, first, a substrate forming step is performed although not shown. The substrate forming step is the process step of forming the first panel <NUM> and the second panel <NUM>. Specifically, the substrate forming step includes making the first panel <NUM> and the second panel <NUM>, for example. In addition, the substrate forming step may further include cleaning the first panel <NUM> and the second panel <NUM> as needed.

Next, the process step of providing first through holes <NUM>, second through holes <NUM>, and an exhaust port <NUM> (hereinafter referred to as an "exhaust port providing step") is performed. This process step includes providing first through holes <NUM> through portions, corresponding to the second spaces <NUM>, of the first panel <NUM>. In the first embodiment, two first through holes <NUM>, namely, one first through hole <NUM> and the other first through hole <NUM>, are provided (see <FIG>). This process step also includes providing second through holes <NUM> through portions, corresponding to the second spaces <NUM>, of the second panel <NUM>. In the first embodiment, two second through holes <NUM>, namely, one second through hole <NUM> and the other second through hole <NUM>, are provided (see <FIG>). The one second through hole <NUM> also serves as the exhaust port <NUM>. Optionally, the exhaust port <NUM> may be provided through the first panel <NUM>. That is to say, the exhaust port <NUM> may be provided through at least one of the first panel <NUM> or the second panel <NUM>.

Next, electric wires <NUM> are arranged (see <FIG>). In the first embodiment, each electric wire <NUM> is arranged to extend from a portion corresponding to the first space <NUM> to an associated one of the first through holes <NUM> (<NUM>, <NUM>) serving as connecting voids. One end, facing the first space <NUM>, of each electric wire <NUM> is electrically connected to the coating <NUM> (see <FIG>).

In addition, each of the first through holes <NUM> (<NUM>, <NUM>) is also provided with a cylindrical member <NUM> having electrical conductivity (see <FIG>). The other end, facing an associated connecting void (first through hole <NUM>), of each electric wire <NUM> is electrically connected to the cylindrical member <NUM> (see <FIG>). An electrically conductive member <NUM> is formed of the electric wire <NUM> and the cylindrical member <NUM>.

Next, as shown in <FIG>, the glue arrangement step is performed. The glue arrangement step is the process step of arranging a hot glue on either the first panel <NUM> or the second panel <NUM>. Specifically, the glue arrangement step includes forming, on the second panel <NUM>, a first part <NUM> of the hot glue, which will serve as the seal <NUM>, and second parts <NUM> of the hot glue, which will serve as boundary walls <NUM>. The glue arrangement step includes applying, onto the second panel <NUM> (i.e., the first surface of the second glass pane <NUM>), a material (first hot glue) for the first part <NUM> and a material (second hot glue) for the second parts <NUM> by using a dispenser, for example.

In the first embodiment, one second part <NUM> is formed to surround the second through hole <NUM> almost entirely (see <FIG>). The circumference of the second part <NUM> is partially discontinued to form the exhaust path <NUM>. Meanwhile, the other second part <NUM> is formed to surround the second through hole <NUM> (see <FIG>). The second part <NUM> has a continuous circumference and forms no exhaust paths.

Optionally, the glue arrangement step may include calcining the respective materials for the first part <NUM> and the second parts <NUM> while drying these materials. For example, the glue arrangement step may include heating the second panel <NUM> on which the material for the first part <NUM> and the material for the second parts <NUM> are applied and may also include heating the first panel <NUM> along with the second panel <NUM>. That is to say, the first panel <NUM> may be heated under the same condition as the second panel <NUM>. This may reduce the difference in the degree of warpage between the first panel <NUM> and the second panel <NUM>.

Subsequently, a pillar forming step is performed. Specifically, the pillar forming step includes forming a plurality of pillars <NUM> in advance and placing the plurality of pillars <NUM> at predetermined locations on the second panel <NUM> by using a chip mounter, for example. Optionally, the plurality of pillars <NUM> may be formed by photolithography and etching techniques. In that case, the plurality of pillars <NUM> may be made of a photocurable material, for example. Alternatively, the plurality of pillars <NUM> may also be formed by a known thin film forming technique.

Next, a gas adsorbent forming step is performed. Specifically, the gas adsorbent forming step includes forming the gas adsorbent <NUM> by applying a solution, in which a getter powder is dispersed, onto a predetermined location on the second panel <NUM> and drying the solution. Note that the glue arrangement step, the pillar forming step, and the gas adsorbent arrangement step may be formed in an arbitrary order.

Thereafter, the glass composite producing step is performed. The glass composite producing step is the process step of producing a glass composite by arranging the second panel <NUM> with respect to the first panel <NUM> such that the second panel <NUM> faces the first panel <NUM> with the first through holes <NUM> aligned with the second through holes <NUM> as shown in <FIG>. The glass composite includes the first panel <NUM>, the second panel <NUM>, and the hot glue (in the first part <NUM> and the second parts <NUM>). In the first embodiment, the first through hole <NUM> and the second through hole <NUM> face each other and the first through hole <NUM> and the second through hole <NUM> face each other.

The first panel <NUM> and the second panel <NUM> are arranged and laid one on top of the other such that the first surface of the first glass pane <NUM> and the first surface of the second glass pane <NUM> face each other and are parallel to each other. The hot glue comes into contact with the first panel <NUM> and the second panel <NUM>, thus forming the glass composite.

Then, the internal space forming step is performed. The internal space forming step is the process step of heating the glass composite to melt the hot glue and thereby form the first part <NUM> that will serve as the seal <NUM> and the second parts <NUM> (partitions) that will be boundary walls <NUM>. Specifically, the internal space forming step includes bonding the first panel <NUM> and the second panel <NUM> together to prepare the assembly <NUM>. That is to say, the internal space forming step is the process step of hermetically bonding the first panel <NUM> and the second panel <NUM> together with the first part <NUM> and the second parts <NUM> (i.e., a bonding step).

The seal <NUM> is a frame-shaped member for hermetically bonding the respective peripheral edge portions of the first panel <NUM> and the second panel <NUM> to form the internal space <NUM> between the first panel <NUM> and the second panel <NUM>. The first part <NUM> serves as the seal.

The second parts <NUM> (partitions) partition the internal space <NUM> into the first space <NUM> that is hermetically sealed except the exhaust path <NUM> and the second spaces <NUM> that are spatially separated from the first space <NUM> and communicate with the first through holes <NUM> and the second through holes <NUM>. The second parts <NUM> hermetically bond the first panel <NUM> and the second panel <NUM> together. One second part <NUM> has the exhaust path <NUM>. The other second part <NUM> has no exhaust paths but is a boundary wall <NUM> (<NUM>) that serves as a seal.

The internal space forming step includes once melting the first hot glue at a predetermined temperature (first melting temperature) Tm1 equal to or higher than the first softening point and thereby hermetically bonding the first panel <NUM> and the second panel <NUM> together. Specifically, the glass composite is arranged in a melting furnace and heated to the first melting temperature Tm1 for a predetermined period (first melting period) tm1.

The first melting temperature Tm <NUM> and the first melting period tm1 are set such that the first panel <NUM> and the second panel <NUM> are hermetically bonded with the first part <NUM> and the second parts <NUM> but that the exhaust path <NUM> is not closed with one of the second parts <NUM>. That is to say, the lower limit of the first melting temperature Tm1 is the first softening point, while the upper limit of the first melting temperature Tm1 is set such that the exhaust path <NUM> is not closed by that one of the second parts <NUM>. For example, if the first softening point and the second softening point are <NUM>, then the first melting temperature Tm1 is set at <NUM>. Also, the first melting period tm1 may be <NUM> minutes, for example. Note that in the internal space forming step, a gas is released from the first part <NUM> and the second parts <NUM> but is adsorbed into the gas adsorbent <NUM>.

In the internal space forming step, the first part <NUM> and second parts <NUM> yet to be softened of the glass composite soften and the first part <NUM> and second parts <NUM> thus softened bond the first panel <NUM> and the second panel <NUM> together. As a result, the assembly <NUM> shown in <FIG> and <FIG> is obtained.

Next, the evacuation step is performed. The evacuation step is the process step of evacuating the first space <NUM> by exhausting the gas from the first space <NUM>. Specifically, the evacuation step is the process step of evacuating the first space <NUM> by exhausting, at a predetermined temperature (exhaust temperature) Te, the gas from the first space <NUM> via the exhaust path <NUM>, one of the second spaces <NUM>, and the exhaust port <NUM> (second through hole <NUM>).

Although not shown, the evacuation step is performed with an exhaust port portion, a closing member, a clip, and a vacuum pump (not shown) used. The vacuum pump is connected to an exhaust port portion which s hermetically connected to the second through hole <NUM>. The closing member closes the first through hole <NUM>. The clip is used to clamp the exhaust port portion and the closing member such that the exhaust port portion and the closing member are close to each other. The first space may be evacuated by exhausting the gas from the first space with the vacuum pump operated in such a state.

The evacuation step includes exhausting the gas from the first space <NUM> at an exhaust temperature Te for a predetermined period (exhaust period) te through the exhaust path <NUM>, the one of the second spaces <NUM>, and the exhaust port <NUM>.

The exhaust temperature Te is set at a temperature higher than the getter activation temperature (of <NUM>, for example) of the gas adsorbent <NUM> but lower than the first softening point and the second softening point (of <NUM>, for example). The exhaust temperature Te may be <NUM>, for example.

This may prevent the first part <NUM> and the second parts <NUM> from being deformed. In addition, the getter of the gas adsorbent <NUM> is activated and the molecules (of a gas) that have been adsorbed into the getter are released from the getter. Then, the molecules (i.e., the gas) released from the getter are exhausted through the first space <NUM>, the exhaust path <NUM>, the one of the second spaces <NUM>, and the exhaust port <NUM>. Thus, in the internal space forming step, the gas adsorbent <NUM> recovers its adsorption ability.

The exhaust period te is set to create an evacuated space <NUM> with a desired degree of vacuum (e.g., a degree of vacuum of <NUM> Pa or less). The evacuation period te may be set <NUM> minutes, for example.

Optionally, the evacuation step may start being performed either after, or during, the internal space forming step, whichever is appropriate. In the latter case, the evacuation step is performed in parallel with the internal space forming step.

Next, the evacuated space forming step (sealing step) is performed. The evacuated space forming step is the process step of sealing the first space <NUM> by closing the exhaust path <NUM> with the partitions deformed while keeping the first space <NUM> evacuated and thereby turning the first space <NUM> into a hermetically sealed evacuated space <NUM>.

Specifically, in the first embodiment, the evacuated space forming step is the process step of forming a boundary wall <NUM> (<NUM>) (see <FIG>) that surrounds the evacuated space <NUM> by deforming the second part <NUM> as a partition and closing the exhaust path <NUM>. The evacuated space forming step includes locally heating the second part <NUM> to a predetermined temperature (second melting temperature) equal to or higher than the second softening point. For the purpose of this local heating, an irradiator configured to emit a laser beam may be used, for example. The irradiator may irradiate the second part <NUM> with a laser beam through the second panel <NUM> from outside of the assembly <NUM>. Note that the local heating may be performed with any member other than the irradiator and the method of local heating is not limited to any particular one.

In the first embodiment, the gas is continuously exhausted in the evacuated space forming step with the same vacuum pump as the one used in the evacuation step still used in the evacuated space forming step. However, this is only an example and should not be construed as limiting. Alternatively, the gas does not have to be exhausted continuously in the evacuated space forming step with the same vacuum pump as the one used in the evacuation step used continuously, as long as a desired degree of vacuum may be maintained.

In this manner, a glass panel unit <NUM> is obtained. As shown in <FIG>, the electric wire <NUM> is arranged to extend from the internal space <NUM> to the connecting void (first through hole <NUM>) by passing through the seal <NUM>. This allows the electric wire <NUM> to be extended out of the glass panel unit <NUM> to supply the internal space <NUM> with electricity.

For example, as shown in <FIG>, a bolt <NUM> may be passed through each second through hole <NUM> (<NUM>, <NUM>) and the tip of the bolt <NUM> protruding through an associated first through hole <NUM> (<NUM>, <NUM>) may be screwed into a nut <NUM>. The bolt <NUM> comes into contact with the cylindrical member <NUM> and thereby is electrically connectible to the electrically conductive member <NUM>. Interposing an external electric wire, terminal, or any other member between either the head of the bolt <NUM> or the nut <NUM> and the surface of glass panel unit <NUM> allows the external electric wire, terminal, or any other member to be electrically connected to the head of the bolt <NUM>, the nut <NUM>, and eventually the electrically conductive member <NUM>.

In this case, the bolt <NUM> is arranged in each of the connecting voids (first through holes <NUM>) and hardly protrudes from the outer surface of the glass panel unit <NUM>. In addition, the electric wire <NUM> is not extended out of the connecting void and does not protrude from the outer surface of glass panel unit <NUM>, and therefore, is hardly disconnected.

Optionally, the internal space <NUM> may be supplied with electricity through the electrically conductive member <NUM> provided for the first through hole <NUM> and the electrically conductive member <NUM> provided for the first through hole <NUM> to allow this glass panel unit <NUM> to serve as a defroster. Alternatively, unless the coating <NUM> is provided, for example, the electrically conductive member <NUM> provided for the first through hole <NUM> and the electrically conductive member <NUM> provided for the first through hole <NUM> may be made electrically conductive with each other via a heater wire, instead of the coating <NUM>. Still alternatively, an antenna, not the heater wire, may be connected to the electrically conductive member <NUM> provided for the first through hole <NUM> and the electrically conductive member <NUM> provided for the first through hole <NUM>.

Next, a glass panel unit <NUM> according to a second embodiment will be described with reference to <FIG> and <FIG>. Note that the second embodiment is mostly the same as the first embodiment described above, and therefore, some features of the second embodiment that are shared in common with the first embodiment will not be described all over again to avoid redundancy.

In the first embodiment described above, the connecting voids are through holes (including the first through holes <NUM> and the second through holes <NUM>). In the second embodiment, on the other hand, the connecting void is a cutout <NUM>. The cutout <NUM> is provided through a portion of the first panel <NUM>.

A terminal <NUM> is connected to one end, extended into the connecting void (cutout <NUM>), of the electric wire <NUM>. This allows an external electric wire to be connected to the electric wire <NUM> more easily.

On the other hand, an antenna (monopole antenna) <NUM> is connected to the other end, located in the first space <NUM>, of the electric wire <NUM>. In addition, a portion, facing the antenna <NUM>, of the coating <NUM> is provided with a cutout <NUM> as shown in <FIG>, thus reducing the chances of causing a decline in the reception sensitivity of the antenna <NUM>.

Next, a glass panel unit <NUM> according to a third embodiment will be described with reference to <FIG>. Note that the third embodiment is mostly the same as the first embodiment described above, and therefore, some features of the third embodiment that are shared in common with the first embodiment will not be described all over again to avoid redundancy.

In the third embodiment, the electric wire <NUM> includes two electric wires <NUM> and <NUM>, which are arranged in parallel with each other. These electric wires <NUM> and <NUM> form an electrical conductor pattern used to supply electricity to a heater, an antenna, a light-emitting element, or any other electrical device arranged in the evacuated space <NUM>. An external electric wire, a terminal, or any other member may be connected to any of these electric wires <NUM>, <NUM> through any of the first through holes <NUM> (connecting voids).

Next, a glass panel unit <NUM> according to a fourth embodiment will be described with reference to <FIG>. Note that the fourth embodiment is mostly the same as the third embodiment described above, and therefore, some features of the fourth embodiment that are shared in common with the third embodiment will not be described all over again to avoid redundancy.

The fourth embodiment includes not only every constituent element of the third embodiment but also a thick terminal connector <NUM> provided for the electric wires <NUM> and <NUM>. The thick terminal connector <NUM> is formed by depositing solder, a metallic plating, an Ag film electrode, or any other electrical conductor on the surface of each of the electric wires <NUM> and <NUM>. Providing the thick terminal connectors <NUM> allows an external electric wire, a terminal, or any other member to be connected to the electric wires <NUM> and <NUM> with more reliability through any of the first through holes <NUM> (connecting void).

Next, a glass panel unit <NUM> according to a fifth embodiment will be described with reference to <FIG>. Note that the fifth embodiment is mostly the same as the third embodiment described above, and therefore, some features of the fifth embodiment that are shared in common with the third embodiment will not be described all over again to avoid redundancy.

In the fifth embodiment, one end portion, facing the second space <NUM>, of one first through hole <NUM> serving as a connecting void is provided with a tapered recess <NUM>, of which the diameter increases as the distance to the second space <NUM> decreases.

A connector <NUM> including a cable <NUM> and electrical contact portions <NUM> is attached into the first through hole <NUM>. The connector <NUM> includes a tip portion, of which the diameter is almost equal to the diameter of the first through hole <NUM>. The tip portion is provided with electrical contact portions <NUM>. As the electrical contact portions <NUM>, an electrical contact portion <NUM> to be connected to the electric wire <NUM> and another electrical contact portion <NUM> to be connected to the electric wire <NUM> are provided separately from each other. Each of the electrical contact portions <NUM> is configured as a metallic plate with flexibility and has its size determined to be fitted into the tapered recess <NUM>. These two electrical contact portions <NUM> have electrical conductivity and are respectively electrically conductive with two electric wires in the cable <NUM>.

When the connector <NUM> is attached to the first through hole <NUM>, first, the electrical contact portions <NUM> are inserted into the first through hole <NUM>. The electrical contact portions <NUM> have flexibility, and therefore, may shrink to pass through the first through hole <NUM>. After having passed through the first through hole <NUM>, the electrical contact portions <NUM> are expanded along the tapered recess <NUM>. This allows the two electrical contact portions <NUM> to be firmly connected to the electric wires <NUM> and <NUM>, respectively. In addition, this also reduces the chances of the connector <NUM> being disconnected accidentally from the first through hole <NUM>.

Next, a glass panel unit <NUM> according to a sixth embodiment will be described with reference to <FIG>. Note that the sixth embodiment is mostly the same as the fifth embodiment described above, and therefore, some features of the sixth embodiment that are shared in common with the fifth embodiment will not be described all over again to avoid redundancy.

The sixth embodiment includes not only every constituent element of the fifth embodiment described above but also a step portion <NUM>, which is provided for an end portion, located adjacent to the external environment, of the first through hole <NUM> serving as a connecting void. The step portion <NUM> is provided locally for only a part of the circumference of the first through hole <NUM>.

In addition, the connector <NUM> includes an insert portion to be inserted into the step portion <NUM>. The insert portion forms part of an end portion, which will be located adjacent to the external environment and will face the step portion <NUM> when the insert portion is inserted into the first through hole <NUM>, of the connector <NUM>. Providing such a step portion <NUM> and insert portion locally for only a part of the circumference of the first through hole <NUM> allows the connector <NUM> to be inserted in a predetermined direction into the first through hole <NUM> and thereby allows associated electrical contact portions <NUM> to be connected to the electric wires <NUM> and <NUM>, respectively.

Next, a glass panel unit <NUM> according to a seventh embodiment will be described with reference to <FIG>. Note that the seventh embodiment is mostly the same as the first embodiment described above, and therefore, some features of the seventh embodiment that are shared in common with the first embodiment will not be described all over again to avoid redundancy.

In the seventh embodiment, a cutout <NUM> serving as a connecting void is provided for one corner portion of the first panel <NUM> which has a rectangular shape in a plan view. This allows an external electric wire, a terminal, or any other member to be electrically connected to the electric wires <NUM> and <NUM> at the corner portion of the glass panel unit <NUM>.

Next, a glass panel unit <NUM> according to an eighth embodiment will be described with reference to <FIG>. Note that the eighth embodiment is mostly the same as the seventh embodiment described above, and therefore, some features of the eighth embodiment that are shared in common with the seventh embodiment will not be described all over again to avoid redundancy.

In the eighth embodiment, a cutout <NUM> serving as a connecting void is provided for a middle portion of one side of the first panel <NUM> which has a rectangular shape in a plan view. This allows an external electric wire, a terminal, or any other member to be electrically connected to the electric wires <NUM> and <NUM> at the middle portion of the one side of the glass panel unit <NUM>.

Next, some variations will be enumerated one after another.

In the embodiments described above, the glass panel unit <NUM> has a rectangular shape. However, this is only an example and should not be construed as limiting. Alternatively, the glass panel unit <NUM> may also have a circular, polygonal, or any other desired shape. That is to say, the first panel <NUM>, the second panel <NUM>, and the seal <NUM> do not have to be rectangular but may also have a circular, polygonal, or any other desired shape. Also, the respective shapes of the first panel <NUM>, the second panel <NUM>, the part <NUM> corresponding to the evacuated space <NUM>, and the boundary walls <NUM> do not have to be the ones used in the embodiments described above but may also be any other shapes that allow a glass panel unit <NUM> of a desired shape to be obtained. Note that the shape and dimensions of the glass panel unit <NUM> may be determined according to the intended use of the glass panel unit <NUM>.

Also, neither the first surface nor the second surface of the first glass pane <NUM> of the first panel <NUM> has to be a plane. Likewise, neither the first surface nor the second surface of the second glass pane <NUM> of the second panel <NUM> has to be a plane.

The first glass pane <NUM> of the first panel <NUM> and the second glass pane <NUM> of the second panel <NUM> do not have to have the same planar shape and planar dimensions. The first glass pane <NUM> and the second glass pane <NUM> do not have to have the same thickness, either. In addition, the first glass pane <NUM> and the second glass pane <NUM> do not have to be made of the same material, either.

Optionally, the first panel <NUM> may further include a coating having desired physical properties and formed on the second surface of the first glass pane <NUM>. Alternatively, the first panel <NUM> may include no coating <NUM>. That is to say, the first panel <NUM> may consist of the first glass pane <NUM> alone.

Optionally, the second panel <NUM> may further include a coating having desired physical properties. The coating may include, for example, at least one of a thin film formed on the first surface of the second glass pane <NUM> or a thin film formed on the second surface of the second glass pane <NUM>. Examples of the coating include an infrared reflective film and an ultraviolet reflective film, both of which reflect light having a particular wavelength.

In the embodiment described above, the internal space <NUM> is partitioned into a single first space <NUM> and a single second space <NUM>. However, this is only an example and should not be construed as limiting. Alternatively, the internal space <NUM> may also be partitioned into one or more first spaces <NUM> and one or more second spaces <NUM>.

In the embodiment described above, the second hot glue is the same as the first hot glue and the second softening point is equal to the first softening point. However, this is only an example and should not be construed as limiting. Alternatively, the second hot glue may also be a different material from the first hot glue. For example, the second hot glue may have a second softening point which is different from the first softening point of the first hot glue.

Furthermore, the first hot glue and the second hot glue do not have to be a glass frit but may also be a low-melting metal or a hot-melt adhesive, for example.

Claim 1:
A glass panel unit (<NUM>) comprising:
a first panel (<NUM>) including a first glass pane (<NUM>);
a second panel (<NUM>) including a second glass pane (<NUM>) and arranged to face the first panel (<NUM>);
a seal (<NUM>) having a frame shape and hermetically bonding respective peripheral edge portions of the first panel (<NUM>) and the second panel (<NUM>) to create an internal space (<NUM>) between the first panel (<NUM>) and the second panel (<NUM>);
a connecting void provided for a portion of at least one of the first panel (<NUM>) and the second panel (<NUM>); and
an electric wire (<NUM>) extended from the internal space (<NUM>) to the connecting void by passing through the seal (<NUM>, <NUM>);
wherein the connecting void is at least one through hole (<NUM> or/and <NUM>) provided through at least one of the first panel (<NUM>) and the second panel (<NUM>),
wherein the internal space (<NUM>) includes a first space (<NUM>) to be a hermetically sealed space and a second space (<NUM>) to be exhaust space,
wherein the seal (<NUM>) includes a part (<NUM>) which has a frame shape and separates the first space (<NUM>) from the external environment and a boundary wall (<NUM>) that separates the first space (<NUM>) from the second space (<NUM>),
wherein the through hole (<NUM> or/and <NUM>) being provided for a portion facing the second space (<NUM>) of at least one of the first panel (<NUM>) and the second panel (<NUM>), and
wherein the electric wire (<NUM>) being extended from the first space (<NUM>) to the through hole (<NUM> or/and <NUM>) by passing through the seal (<NUM>, <NUM>).