Sealing of electronic device using absorbing layer for glue line

In one embodiment of the invention, a first absorbing layer is on a substrate and/or a second absorbing layer is on a heat-activated adhesive. If the IR source that supplies IR radiation is present on the substrate-side, then the absorption percentage of the substrate is less than the absorption percentage of the first absorbing layer if present and less than the absorption percentage of the second absorbing layer if present. If the IR source that supplies IR radiation is present on the “encapsulation cover”-side, then the absorption percentage of the encapsulation cover is less than the absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. The substrate and the encapsulation cover have a low thermal conductivity.

BACKGROUND OF THE INVENTION

An organic electronic device such as, for example, an organic light emitting diode (“OLED”) display, an OLED light source for area illumination, an organic light sensor array, an organic transistor array, or an organic solar cell array require protection from oxygen and moisture in the atmosphere, and therefore employ some form of encapsulation. One common procedure to encapsulate the organic electronic device is to sandwich it between a substrate and an encapsulation cover, and an adhesive around the perimeter of the device holds together the substrate and the encapsulation cover such that there is a continuous perimeter seal around the device.

Typically, the substrate and the encapsulation cover are sealed together using UV-curable adhesive or thermal-cure adhesive. In many cases, use of the thermal-cure adhesive would be advantageous. Thermal-cure adhesive provides many advantages such as good performance and predictable results due to the maturity of the technology. The thermal-cure adhesive needs to be heated to a high temperature in order to cure it. Because of the thickness of the substrate and/or the encapsulation cover (e.g., the thickness can vary from tens of microns to over one millimeter), the substrate and/or the encapsulation cover can be efficient absorbers of the infrared (“IR”) radiation supplied to cure the thermal-cure adhesive and therefore a substantial part of the IR radiation supplied to cure the thermal-cure adhesive can be absorbed by these components thus these components are exposed to high temperatures. The absorption of the supplied IR radiation can damage, for example, the organic active layers of the electronic device, the substrate, and/or the encapsulation cover. In the case of the substrate and/or the encapsulation cover, the heating to the high temperatures can cause these components to become warped.

For the foregoing reasons, there exists a need to encapsulate the organic electronic device using thermal-cure adhesive without damaging components of the encapsulated device such as the organic active layers, the substrate, and/or the encapsulation cover.

SUMMARY

An embodiment of an encapsulated organic electronic device is described that includes: a substrate, an organic electronic device on the substrate, and a heat-activated adhesive that is on the substrate and surrounds a perimeter of the organic electronic device. The electronic device also includes an encapsulation cover that is on the heat-activated adhesive. A first absorbing layer is between the substrate and the heat-activated adhesive and is in proximity to the adhesive. In addition or alternatively, a second absorbing layer is between the encapsulation cover and the adhesive and is in proximity to the adhesive. If an IR source that supplies IR radiation is on a substrate-side, then an IR radiation absorption percentage of the substrate is less than an absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. If another IR source is on an “encapsulation cover”-side, then an absorption percentage of the encapsulation cover is less than an absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present.

DETAILED DESCRIPTION

In an embodiment of this invention, a first absorbing layer is on a substrate and/or a second absorbing layer is on a heat-activated adhesive. If the IR source that supplies IR radiation is present on a substrate-side, then an absorption percentage of the substrate is less than an absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. If the IR source that supplies IR radiation is present on an “encapsulation cover”-side, then an absorption percentage of the encapsulation cover is less than an absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. The substrate and the encapsulation cover have a low thermal conductivity. When the substrate and the encapsulation cover are brought together so as to seal the organic electronic device, the first absorbing layer if present is in proximity to the heat-activated adhesive and the second absorbing layer if present is in proximity to the heat-activated adhesive. Because the absorbing layer(s) that are present have a higher absorption percentage than the substrate and/or the encapsulation cover, more of the IR radiation reaches the absorbing layer(s) and since the absorbing layer(s) are in proximity to the heat-activated adhesive, more IR radiation is transferred to the heat-activated adhesive.

FIG. 1shows a cross-section of an embodiment of an encapsulated organic electronic device106according to the present invention. InFIG. 1, an organic electronic device112is on a substrate109. As used within the specification and the claims, the term “on” includes when devices, components, or layers are in physical contact and when devices, components, or layers are separated by one or more intervening layers. Optionally, an absorbing layer115ais on the substrate109. A heat-activated adhesive118is on the substrate109, or on the absorbing layer115aif present. Optionally, an absorbing layer115bis on the heat-activated adhesive118. The absorbing layer115aif present, the heat-activated adhesive118, and the absorbing layer115bif present are all around the perimeter of the organic electronic device112. At least one of the absorbing layers115a, bis present in the encapsulated organic electronic device106. One or more IR sources supply localized IR radiation127that is absorbed by the absorbing layer115aif present and the absorbing layer115bif present and the resulting heat is transferred from the absorbing layer(s) to the heat-activated adhesive118in order to cure it. These components are described in greater detail below.

The substrate109supports the organic electronic device112and protects the organic electronic device (e.g., the organic layers) from moisture and oxygen. The substrate109is transparent or opaque (e.g., if the IR source that supplies IR radiation is not on the substrate-side, then the substrate109can be opaque). The substrate109can be comprised of, for example, glass, quartz, or plastic; preferably, the substrate109is comprised of glass. The preferred thickness of the substrate109depends on the material used and the specific application of the device; for example, the thickness of the substrate109can range from tens of microns to approximately one millimeter. The substrate109has low thermal conductivity. For example, the thermal conductivity of the substrate109is within the range of about 0.1 W/mK to about 10 W/mK. If the IR source that supplies IR radiation is present on the substrate-side, then the IR radiation absorption percentage of the substrate109is less than the absorption percentage of the absorbing layer115aif present and the absorption percentage of the absorbing layer115bif present. Preferably, the absorption percentage of the IR radiation of the substrate109is less than 50%, and more preferably, it is less than 10%. Materials such as, for example, glass have the desirable absorption percentage.

Organic Electronic Device112:

The organic electronic device112is a device that, for example, includes an anode, a cathode, and at least one organic layer between the anode and the cathode; the at least one organic layer includes an organic active layer. Alternatively, rather than an anode and a cathode, the contacts can be a source, drain, and gate. Examples of organic electronic devices are an OLED display, an OLED light source for area illumination, an organic light sensor array, an organic transistor array, or an organic solar cell array.

One or both of the absorbing layers115a,bare present in the encapsulated organic electronic device106. The absorbing layers115a,babsorb at least a substantial percentage of the received IR radiation; for example, the absorbing layers115a,babsorb at least 50% of the IR radiation received, preferably, they absorb at least 70% of the IR radiation. The absorbing layers115a,bhave good adhesion to the substrate109, the encapsulation cover121, and/or the heat-activated adhesive118. If the heat-activated adhesive118has a high thermal conductivity, then the absorbing layer(s)115a,bcover at least a portion of the heat-activated adhesive118; otherwise, if the heat-activated adhesive118has a low thermal conductivity, then the absorbing layer(s)115a,bcover at least a substantial portion of the heat-activated adhesive118.

Also, the absorbing layer(s)115a,bcan be made of materials whose surface properties can be modified prior to encapsulation to increase absorption and/or reduce reflection of the IR radiation. Examples of such modification include exposure to light and/or chemicals, or mechanical action such as physically roughening the material.

In addition, anti-reflection coatings or layers can be deposited on one or both absorbing layers115a,bin order to, for example, minimize reflection of the IR radiation.

The heat-activated adhesive can be a thermal-cure epoxy (e.g., a thermal-cure organic epoxy or a thermal-cure organo-metallic epoxy in which the epoxy is single component or multi-component), a compound that is initially in a fluid phase (e.g., liquid or paste) and is converted by heat to a solid amorphous or crystalline phase compound (e.g., a silicon-based compound), glass, glass-frit, a solder (e.g., a metal or an alloy), or a glue that is at least partially cured by heat.

When the heat-activated adhesive118is exposed to IR radiation, if the absorbing layer115ais present, the heat-activated adhesive118may react with the absorbing layer115ato produce an intermixed layer between the absorbing layer115aand the heat-activated adhesive118; and if the absorbing layer115bis present, the heat-activated adhesive118may react with the absorbing layer115bto produce another intermixed layer between the heat-activated adhesive118and the absorbing layer115b.

The heat-activated adhesive118can at least substantially absorb the IR radiation, or alternatively, the heat-activated adhesive118at least partially absorbs the IR radiation or only minimally absorbs the radiation. By using one or both absorbing layers115a,b, the heat-activated adhesive118can be chosen primarily for its bonding capability rather than its IR absorbing capability.

Optionally, a two-stage sealing process can be used where in an earlier stage, prior to completely curing the heat-activated adhesive118, the adhesive is spot-cured. For example, the corners of the seal frame of the larger substrate (e.g., this is the substrate before singulation on which are multiple electronic devices) can be spot-cured, a pattern on the seal frame of the larger substrate can be spot-cured, or the corners of the seal frame of each individual electronic device can be spot-cured. Spot-curing can be used to, for example, minimize or avoid warpage.

The encapsulation cover121covers the organic electronic device112and protects the device from oxygen and moisture. The encapsulation cover121is transparent or opaque (e.g., if the IR source that supplies IR radiation is not on the “encapsulation cover”-side, then the encapsulation cover121can be opaque). The encapsulation cover121can be comprised of, for example, glass, quartz, or plastic; preferably, the encapsulation cover121is comprised of glass. The preferred thickness of the encapsulation cover121depends, in part, on the material used and the specific application of the device; for example, the thickness of the encapsulation cover121can range from 10 micrometers to 5 millimeters, preferably, the thickness ranges from 0.1 millimeters to 1.0 millimeters. The encapsulation cover121has low thermal conductivity. For example, the thermal conductivity of the encapsulation cover121is within the range of 0.1 W/mK to 10 W/mK. If an IR source that supplies IR radiation is present on the “encapsulation cover”-side, then the absorption percentage of the IR radiation of the encapsulation cover121is less than the absorption percentage of the absorbing layer115aif present and the absorption percentage of the absorbing layer115bif present. Preferably, the absorption percentage of the IR radiation of the encapsulation cover121is less than 50%, preferably, less than 10%. Materials such as, for example, glass have the desirable absorption percentage.

The IR source supplies the IR radiation127that is absorbed by the absorbing layer(s)115a,b. The IR source can be, for example, a localized IR source such as an IR laser (e.g., a semiconductor laser, a gas laser (e.g., a carbon dioxide laser), or a metal vapor laser), an IR LED, a hot object (e.g., a heated filament, a heated bar, or a patterned hot plate/stamp/stencil that is pressed against the substrate109and/or the encapsulation cover121over the areas in which the heat-activated adhesive is present). The IR radiation is applied to the entire seal frame (e.g., the heat-activated adhesive118) by, for example, moving the electronic device (e.g., in this case, the electronic device is placed on an x-y stage and the stage moves the device under a fixed localized IR source), moving the localized IR source, or by scanning optics.

Alternatively, the IR source can be an IR flood source. In one configuration, the flood source is an areal IR source that supplies IR radiation in the x-y direction, and IR absorbing or reflecting masks are employed so that the IR radiation is localized/patterned so that substantially only the heat-activated adhesive118and/or the absorbing layer is exposed to the IR radiation127. In another configuration, the flood source is a scanned linear source; the scanned linear source supplies a line of IR radiation. Again, masks are employed to produce localized IR radiation so that substantially only the heat-activated adhesive118and/or the absorbing layer is exposed to the IR radiation127. The IR radiation is sweeped across the entirety of the device (including across the seal frame) by either moving the electronic device across the scanned linear source (e.g., the electronic device is on an x-y stage and the device is moved across a fixed linear source), or by moving the scanned linear source across the electronic device (e.g., the electronic device is in a fixed position and the linear source is moved across the electronic device).

Alternatively, the IR source can be a patterned IR source that supplies patterned IR radiation. Masks and/or optics can be used so that the supplied IR radiation is patterned. The patterned IR source can step from one electronic device to another, or alternatively, the devices are moved across a fixed patterned IR source. Alternatively, the IR source can supply a pulsed beam that is scanned in order to cure the seal frame.

FIG. 2ashows a first configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the absorbing layer115ais on the substrate109around the perimeter of the organic electronic device112, and the heat-activated adhesive118is on the absorbing layer115aaround the perimeter of the organic electronic device112. The encapsulation cover121is on the heat-activated adhesive118. In one scenario, the absorbing layer115ais deposited on the substrate109around the perimeter of the organic electronic device112. The heat-activated adhesive118is deposited on the encapsulation cover121such that when the substrate109and the encapsulation cover121are brought together so as to seal the organic electronic device112, the heat-activated adhesive118is around the perimeter of the organic electronic device112. Alternatively, instead of depositing the absorbing layer115aon the substrate109and depositing the heat-activated adhesive118on the encapsulation cover121, the absorbing layer115aand the heat-activated adhesive118can be deposited on other components and in other sequences. For example, in another scenario, the absorbing layer115acan be deposited on the substrate109and the heat-activated adhesive118can be deposited on the absorbing layer115a. In yet another scenario, the heat-activated adhesive118can be deposited on the encapsulation cover121and the absorbing layer115acan be deposited on the heat-activated adhesive118.

The absorbing layer115acan be deposited using selective or non-selective deposition techniques. For example, the absorbing layer115acan be deposited using selective deposition techniques such as, for example, any printing technique that is suitable for depositing the layer in a patterned manner with adequate precision; examples of such printing techniques include screen printing, ink-jet printing, or dispensing through a needle of a syringe. Alternatively, the absorbing layer115acan be deposited using non-selective uniform deposition techniques such as spin coating, thermal evaporation, sputtering, or chemical vapor deposition; if a non-selective deposition technique is used, then a subsequent removal or patterning step (e.g., laser ablation or photolithography process) is employed to remove the absorbing material from certain areas. Similarly, the heat-activated adhesive118can be deposited using selective deposition techniques (e.g., any printing technique that is suitable for depositing the adhesive in a patterned manner with adequate precision; examples of such printing techniques include screen printing, ink-jet printing, or dispensing through a needle of a syringe), or alternatively, deposited using non-selective deposition techniques (e.g., spin coating, thermal evaporation, sputtering, or chemical vapor deposition) and a subsequent removal step.

InFIG. 2a, the IR source is localized IR source124located on the substrate-side of the encapsulated electronic device106and it supplies IR radiation127that is at least substantially transmitted through the substrate109and is at least substantially absorbed by the absorbing layer115a. Due to the proximity of the absorbing layer115ato the heat-activated adhesive118, the heat absorbed by the absorbing layer115ais at least partially transferred to the heat-activated adhesive118. So that a greater percentage of the supplied IR radiation is absorbed by the absorbing layer115arather than the substrate109, the absorption percentage of the IR radiation of the substrate109is less than the absorption percentage of the absorbing layer115a; preferably, the absorption percentage of the substrate109is less than 50%, and more preferably, it is less than 10%. The substrate109and the encapsulation cover121have low thermal conductivity.

FIG. 2bshows a second configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the heat-activated adhesive118is on the substrate109around the perimeter of the organic electronic device112, and the absorbing layer115bis on the heat-activated adhesive118around the perimeter of the organic electronic device112. The encapsulation cover121is on the absorbing layer115b. In one scenario, the heat-activated adhesive118is deposited on the substrate109around the perimeter of the organic electronic device112, and the absorbing layer115bis deposited on the heat-activated adhesive118around the perimeter of the organic electronic device112. Alternatively, instead of depositing the heat-activated adhesive118on the substrate109and then the absorbing layer115bon the heat-activated adhesive118, the heat-activated adhesive118and the absorbing layer115bcan be deposited on other components and in other sequences. For example, in another scenario, the heat-activated adhesive118is deposited on the substrate109around the perimeter of the organic electronic device112, and the absorbing layer115bis deposited on the encapsulation cover121such that when the substrate109and the encapsulation cover121are brought together so as to seal the organic electronic device112, the absorbing layer115bis around the perimeter of the organic electronic device112. In yet another scenario, the absorbing layer115bcan be deposited on the encapsulation cover121and the heat-activated adhesive118can be deposited on the absorbing layer115band these two are deposited such that when the substrate109and the encapsulation cover121are brought together so as to seal the organic electronic device112, the absorbing layer115band the heat-activated adhesive118are around the perimeter of the organic electronic device112.

The absorbing layer115bcan be deposited using the selective or non-selective deposition techniques described earlier for the deposition of the absorbing layer115a. Similarly, the heat-activated adhesive118can be deposited using the selective or non-selective deposition techniques described earlier.

InFIG. 2b, the IR source is localized IR source124located on the substrate-side of the encapsulated electronic device106and it supplies IR radiation127that is at least substantially transmitted through the substrate109, and at least some of this radiation may be absorbed by the heat-activated adhesive118. The IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the absorbing layer115band due to the absorbing layer's proximity to the heat-activated adhesive118, the heat is at least substantially transferred back to the heat-activated adhesive118. The substrate109has the absorption and thermal conductivity properties described earlier forFIG. 2a.

FIG. 2cshows a third configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the absorbing layer115ais on the substrate109around the perimeter of the organic electronic device112; the heat-activated adhesive118is on the absorbing layer115aaround the perimeter of the organic electronic device112; and the absorbing layer115bis on the heat-activated adhesive118around the perimeter of the organic electronic device112. The encapsulation cover121is on the absorbing layer115b. In one scenario, the absorbing layer115ais deposited on the substrate109around the perimeter of the organic electronic device112; the heat-activated adhesive118is deposited on the absorbing layer115aaround the perimeter of the organic electronic device112; and the absorbing layer115bis deposited on the heat-activated adhesive118around the perimeter of the organic electronic device112.

Alternatively, instead of depositing the absorbing layer115aon the substrate109, depositing the heat-activated adhesive118on the absorbing layer115a, and depositing the absorbing layer115bon the heat-activated adhesive118, the absorbing layer115a, the heat-activated adhesive118, and the absorbing layer115bcan be deposited on other components and in other sequences. For example, in another scenario, the absorbing layer115bcan be deposited on the encapsulation cover121, the heat-activated adhesive118can be deposited on the absorbing layer115b, and the absorbing layer115acan be deposited on the heat-activated adhesive118and all three sealing components are deposited such that when the substrate109and the encapsulation cover121are brought together so as to seal the organic electronic device112, the three sealing components are around the perimeter of the organic electronic device112. In yet another scenario, the absorbing layer115acan be deposited on the substrate109, the heat-activated adhesive118can be deposited on the absorbing layer115a, and the absorbing layer115bcan be deposited on the encapsulation cover121such that when the substrate109and the encapsulation cover121are brought together so as to seal the organic electronic device112, the absorbing layer115bis around the perimeter of the organic electronic device112. In another scenario, the absorbing layer115acan be deposited on the substrate109, the absorbing layer115bcan be deposited on the encapsulation cover121, and the heat-activated adhesive118can be deposited on the absorbing layer115b. The absorbing layer115band the heat-activated adhesive118are deposited such that when the substrate109and the encapsulation cover121are brought together so as to seal the organic electronic device112, these two sealing components are around the perimeter of the organic electronic device112.

The absorbing layers115a,bcan be deposited using the selective or non-selective deposition techniques described earlier for the deposition of the absorbing layer115a. Similarly, the heat-activated adhesive118can be deposited using the selective or non-selective deposition techniques described earlier.

InFIG. 2c, the IR source is localized IR source124located on the substrate-side of the encapsulated electronic device106and it supplies IR radiation127that is at least substantially transmitted through the substrate109and is at least substantially absorbed by the absorbing layer115a. Due to the proximity of the absorbing layer115ato the heat-activated adhesive118, the heat absorbed by the absorbing layer115ais at least partially transferred to the heat-activated adhesive118. In addition, the IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the absorbing layer115band due to this absorbing layer's proximity to the heat-activated adhesive118, the heat is at least substantially transferred back to the heat-activated adhesive118. Alternatively, the absorbing layer115bcan be an IR reflective layer that reflects the IR radiation transmitted through the adhesive back to the adhesive and/or the absorbing layer115a. The substrate109has the absorption and thermal conductivity properties described earlier forFIG. 2a.

FIG. 2dshows a fourth configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the absorbing layer115ais on the substrate109around the perimeter of the organic electronic device112, and the heat-activated adhesive118is on the absorbing layer115aaround the perimeter of the organic electronic device112. The encapsulation cover121is on the heat-activated adhesive118. The sealing components (e.g., the absorbing layer115aand the heat-activated adhesive118) can be deposited on the various components (e.g., the substrate109, the absorbing layer115a, the heat-activated adhesive118, and the encapsulation cover121) in the combinations described earlier forFIG. 2a.

InFIG. 2d, the IR source is localized IR source130located on the “encapsulation cover”-side of the encapsulated electronic device106and it supplies IR radiation127that is at least substantially transmitted through the encapsulation cover121, and at least some of this radiation may be absorbed by the heat-activated adhesive118. The IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the absorbing layer115aand due to the absorbing layer's proximity to the heat-activated adhesive118, the heat is at least substantially transferred back to the heat-activated adhesive118. So that a greater percentage of the supplied IR radiation is absorbed by the heat-activated adhesive118and/or the absorbing layer115arather than the encapsulation cover121, the absorption percentage of the IR radiation of the encapsulation cover121is less than the absorption percentage of the absorbing layer115a; preferably, the absorption percentage of the encapsulation cover121is less than 50%, and more preferably, it is less than 10%. The encapsulation cover121and the substrate109have low thermal conductivity.

FIG. 2eshows a fifth configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the heat-activated adhesive118is on the substrate109around the perimeter of the organic electronic device112; and the absorbing layer115bis on the heat-activated adhesive118around the perimeter of the organic electronic device112. The encapsulation cover121is on the absorbing layer115b. The sealing components (e.g., the heat-activated adhesive118and the absorbing layer115b) can be deposited on the various components (e.g., the substrate109, the heat-activated adhesive118, the absorbing layer115b, and the encapsulation cover121) in the combinations described earlier forFIG. 2b.

InFIG. 2e, the IR source is localized IR source130located on the “encapsulation cover”-side of the encapsulated electronic device106and it supplies IR radiation127that is at least substantially transmitted through the encapsulation cover121and is at least substantially absorbed by the absorbing layer115b. Due to the proximity of the absorbing layer115bto the heat-activated adhesive118, the heat absorbed by the absorbing layer115bis at least partially transferred to the heat-activated adhesive118. The encapsulation cover121has the absorption and thermal conductivity properties described earlier forFIG. 2d.

FIG. 2fshows a sixth configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the absorbing layer115ais on the substrate109, the heat-activated adhesive118is on the absorbing layer115a, and the absorbing layer115bis on the heat-activated adhesive118and all are around the perimeter of the organic electronic device112. The encapsulation cover121is on the absorbing layer115b. The sealing components (e.g., the absorbing layer115a, the heat-activated adhesive118, and the absorbing layer115b) can be deposited on the various components (e.g., the substrate109, the absorbing layer115a, the heat-activated adhesive118, the absorbing layer115b, and the encapsulation cover121) in the combinations described earlier forFIG. 2c.

InFIG. 2f, the IR source is localized IR source130located on the “encapsulation cover”-side of the encapsulated electronic device106and it supplies IR radiation127that is at least substantially transmitted through the encapsulation cover121and is at least substantially absorbed by the absorbing layer115band due to the proximity of the absorbing layer115bto the heat-activated adhesive118, the heat absorbed by the absorbing layer115bis at least partially transferred to the heat-activated adhesive118. In addition, the IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the absorbing layer115aand due to this absorbing layer's proximity to the heat-activated adhesive118, the heat is at least substantially transferred back to the heat-activated adhesive118. Alternatively, the absorbing layer115acan be an IR reflective layer that reflects the IR radiation transmitted through the adhesive back to the adhesive and/or the absorbing layer115b. The encapsulation cover121has the absorption and thermal conductivity properties described earlier forFIG. 2d.

FIG. 2gshows a seventh configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the absorbing layer115ais on the substrate109, and the heat-activated adhesive118is on the absorbing layer115aand both these sealing components are around the perimeter of the organic electronic device112. The encapsulation cover121is on the heat-activated adhesive118. The sealing components (e.g., the absorbing layer115aand the heat-activated adhesive118) can be deposited on the various components (e.g., the substrate109, the absorbing layer115a, the heat-activated adhesive118, and the encapsulation cover121) in the combinations described earlier forFIG. 2a.

InFIG. 2g, the IR source is the localized IR source124located on the substrate-side and the localized IR source130located on the “encapsulation cover”-side of the encapsulated electronic device106. The IR source124located on the substrate-side supplies IR radiation127that is substantially transmitted through the substrate109and is at least substantially absorbed by the absorbing layer115a. Due to the proximity of the absorbing layer115ato the heat-activated adhesive118, the heat absorbed by the absorbing layer115ais at least partially transferred to the heat-activated adhesive118. The IR source130located on the “encapsulation cover”-side supplies IR radiation127that is at least substantially transmitted through the encapsulation cover121, and at least some of this radiation may be absorbed by the heat-activated adhesive118. From this source, the IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the absorbing layer115aand due to the absorbing layer's proximity to the heat-activated adhesive118, the heat is at least partially transferred back to the heat-activated adhesive118. So that a greater percentage of the supplied IR radiation is absorbed by the absorbing layer115arather than the substrate109, the absorption percentage of the IR radiation of the substrate109is less than the absorption percentage of the absorbing layer115a; preferably, the absorption percentage of the substrate109is less than 50%, and more preferably, it is less than 10%. So that a greater percentage of the supplied IR radiation is absorbed by the heat-activated adhesive118and/or the absorbing layer115arather than the encapsulation cover121, the absorption percentage of the IR radiation of the encapsulation cover121is less than the absorption percentage of the absorbing layer115a; preferably, the absorption percentage of the encapsulation cover121is less than 50%, and more preferably, it is less than 10%. The substrate109and the encapsulation cover121have low thermal conductivity.

FIG. 2hshows an eighth configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the heat-activated adhesive118is on the substrate109around the perimeter of the organic electronic device112, and the absorbing layer115bis on the heat-activated adhesive118around the perimeter of the organic electronic device112. The encapsulation cover121is on the absorbing layer115b. The sealing components (e.g., the heat-activated adhesive118and the absorbing layer115b) can be deposited on the various components (e.g., the substrate109, the heat-activated adhesive118, the absorbing layer115b, and the encapsulation cover121) in the combinations described earlier forFIG. 2b.

InFIG. 2h, the localized IR source124located on the substrate-side supplies IR radiation127that is substantially transmitted through the substrate109, and at least some of this radiation may be absorbed by the heat-activated adhesive118. The IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the absorbing layer115band due to the absorbing layer's proximity to the heat-activated adhesive118, the heat is at least partially transferred back to the heat-activated adhesive118. The IR source130located on the “encapsulation cover”-side supplies IR radiation127that is at least substantially transmitted through the encapsulation cover121and is at least substantially absorbed by the absorbing layer115b. Due to the proximity of the absorbing layer115bto the heat-activated adhesive118, the heat absorbed by the absorbing layer115bis at least partially transferred to the heat-activated adhesive118. The substrate109and the encapsulation cover121have the absorption and thermal conductivity properties described earlier forFIG. 2g.

FIG. 2ishows a ninth configuration of the embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. In this configuration, the absorbing layer115ais on the substrate109, the heat-activated adhesive118is on the absorbing layer115a, and the absorbing layer115bis on the heat-activated adhesive118, and all these sealing components are around the perimeter of the organic electronic device112. The encapsulation cover121is on the absorbing layer115b. The sealing components (e.g., the absorbing layer115a, the heat-activated adhesive118, and the absorbing layer115b) can be deposited on the various components (e.g., the substrate109, the absorbing layer115a, the heat-activated adhesive118, the absorbing layer115b, and the encapsulation cover121) in the combinations described earlier forFIG. 2c.

InFIG. 2i, the localized IR source124located on the substrate-side supplies IR radiation127that is substantially transmitted through the substrate109and is at least substantially absorbed by the absorbing layer115aand due to the absorbing layer's proximity to the heat-activated adhesive118, the heat is at least partially transferred to the heat-activated adhesive118. The IR source130located on the “encapsulation cover”-side supplies IR radiation127that is at least substantially transmitted through the encapsulation cover121and is at least substantially absorbed by the absorbing layer115band due to the proximity of the absorbing layer115bto the heat-activated adhesive118, the heat absorbed by the absorbing layer115bis at least partially transferred to the heat-activated adhesive118. The IR radiation that is transmitted through the heat-activated adhesive118is at least substantially absorbed by the corresponding absorbing layer115a,band the heat is at least substantially transferred back to the heat-activated adhesive118. The substrate109and the encapsulation cover121have the absorption and thermal conductivity properties described earlier forFIG. 2g.

FIG. 3shows another embodiment of the system used to produce the encapsulated organic electronic device106according to the present invention. InFIG. 3, the IR flood source126is located on the substrate-side of the encapsulated electronic device106, and the IR flood source126supplies the IR radiation127. A mask130is on or above the substrate109(inFIG. 3, the mask is shown above) and is used to localize/pattern the IR radiation127so that substantially only the heat-activated adhesive118and/or the absorbing layer115ais exposed to the IR radiation127. The mask can either absorb or reflect the IR radiation127. In one configuration, the IR flood source126is an areal IR source that supplies IR radiation in the x-y direction. In another configuration, the IR flood source126is a scanned linear source; the scanned linear source supplies a line of IR radiation. The IR radiation is sweeped across the entirety of the seal frame by either moving the electronic device across the scanned linear source, or by moving the scanned linear source across the electronic device. Alternatively, the IR flood source126can be located on the “encapsulation cover”-side of the encapsulated electronic device106, and another mask is also on this side to localize/pattern the IR radiation127. In addition, alternatively, the IR flood sources and the corresponding masks can be located on both the substrate-side and the “encapsulated cover”-side of the electronic device106. The encapsulated electronic device106can be configured as shown inFIG. 3(in this configuration, the absorbing layer115ais on the substrate109, and the heat-activated adhesive118is on the absorbing layer115a; this configuration is similar to the configuration shown inFIG. 2a) or alternatively, it can be configured as shown inFIG. 2borFIG. 2c.

FIG. 4is a flowchart that shows an embodiment of a method to encapsulate the organic electronic device112according to the present invention. In block503, an organic electronic device112is fabricated on a substrate109. In block506, optionally, a first absorbing layer is deposited on the substrate or the encapsulation cover. In block509, the heat-activated adhesive is deposited on the first absorbing layer if present, the substrate, or the encapsulation cover. In block512, optionally, a second absorbing layer is deposited on the heat-activated adhesive, the substrate, or the encapsulation cover. The first absorbing layer if present, the heat-activated adhesive, and the second absorbing layer if present can be deposited in any of the various combinations described forFIGS. 2a–c. The absorbing layer(s) and the heat-activated adhesive can be deposited using any of the deposition techniques described earlier. In block515, the substrate and the encapsulation cover are brought closer together so as to encapsulate (i.e., seal) the organic electronic device. In block518, the localized IR radiation is applied to the heat-activated adhesive to cure it. The first absorbing layer if present and the second absorbing layer if present absorb the IR radiation and transfer the generated heat to the heat-activated adhesive in order to cure it. The IR source that supplies the IR radiation can be located on the substrate-side and/or the IR source can be located on the “encapsulation cover”-side. If the IR source is on the substrate-side, then an absorption percentage of the substrate is less than an absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. If the IR source is on the “encapsulation cover”-side, then an absorption percentage of the encapsulation cover is less than an absorption percentage of the first absorbing layer if present and less than an absorption percentage of the second absorbing layer if present. The substrate and the encapsulation cover have a low thermal conductivity.

As any person of ordinary skill in the art of organic electronic device fabrication will recognize from the description, figures, and examples that modifications and changes can be made to the embodiments of the invention without departing from the scope of the invention defined by the following claims.