Polymer optoelectronic device made of thermoplastic material and packaging method thereof

Abstract

The present invention provides a polymer optoelectronic device made of thermoplastic material and a packaging method thereof. The polymer optoelectronic device is encapsulated with three layers of thermoplastic material: an upper layer comprising a polymer flat sheet, a middle layer comprising a light-absorbing film, and a lower layer comprising a optoelectronic device structure. The thermal expansion coefficients of the upper, middle, and lower layers differ by no more than 10%, preferably no more than 5%, and more preferably no more than 3%. Because the polymer optoelectronic device is manufactured using a precision injection molding process using thermoplastic material, it is easier to mass-produce, has lower product costs, faster production speeds, and greater versatility than conventional optoelectronic devices made from glass.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a polymer optoelectronic device made of thermoplastic material and a packaging method thereof. Background Art

[0002] With the widespread use of smartphones, research into optoelectronic devices (such as lens modules and image sensors) for smartphones has rapidly advanced. Smartphones are high-volume, highly integrated electronic systems that place high demands on the performance, size, reliability, and uniformity of individual components (including optoelectronics). Due to the limited internal space of smartphones, optoelectronic devices within smartphones are becoming increasingly miniaturized and modularized. This requires precise, rapid, reliable, and mass-produced processing and packaging technologies to achieve these miniaturized optoelectronic devices.

[0003] At present, conventional optoelectronic devices are made of glass materials. Although glass materials have excellent optical properties, the processing speed, yield and cost of glass-based optical devices are still difficult to meet the needs of a large number of smartphones. Therefore, optoelectronic devices based on polymer materials have been widely developed. Using precision injection molding technology, polymer optoelectronic devices can be processed in batches with precision, speed and high uniformity. Conventional packaging methods for polymer optoelectronic devices include: hot press bonding, dispensing packaging, ultrasonic welding, and laser welding. The above methods have shortcomings in the packaging of polymer optoelectronic devices used in smartphones:

[0004] (1) Hot-press bonding is slow and can easily cause deformation of polymer optoelectronic devices;

[0005] (2) Glue dispensing packaging has weak bonding strength; the fusion area is wide, and the fusion area after dispensing is easy to spread to the functional area of the optical device, affecting the function of the device;

[0006] (3) Ultrasonic welding requires the design and processing of special welding lines; the welding area is wide, and the fusion area after ultrasonic welding is easy to spread to the functional area of the optical device, affecting the function of the device; at the same time, ultrasonic vibration energy is easy to damage the micro-nano structure of the optical device;

[0007] (4) Laser welding: Conventional laser welding point scanning method generates stress in the welding area, causing deformation of polymer optical devices and affecting device function.

[0008] Micro-nano polymer optical devices used in smartphones urgently need optical devices produced by precise, fast, reliable, and highly uniform batch packaging methods. Summary of the Invention

[0009] To address the above-mentioned problems, the present invention provides a polymer photovoltaic device made of thermoplastic material. The polymer photovoltaic device is encapsulated by three layers of thermoplastic material, wherein the upper layer is a polymer flat sheet, the middle layer is a light-absorbing film, and the lower layer is a photovoltaic device structural layer. The thermal expansion coefficients of the materials of the upper, middle, and lower layers differ by no more than 10%, preferably no more than 5%, and more preferably no more than 3%. The upper and lower layers of the three thermoplastic materials are transparent but not absorb welding laser light, while the middle layer absorbs welding laser light that passes through the upper and / or lower layers, thereby welding and encapsulating the three layers together. The photovoltaic device structural layer includes no fewer than five photovoltaic device units, each formed in the photovoltaic device structural layer by a precision injection molding process. Each photovoltaic device unit has a size of less than 6 mm x 6 mm, the thickness of the upper and lower layers is no more than 0.6 mm, and the thickness of the middle layer is no more than 100 μm.

[0010] In one embodiment, the size of the upper layer, the middle layer and the lower layer is not less than 1 cm x 1 cm.

[0011] In one embodiment, the optoelectronic device unit is a scattering light device with a size no greater than 4 mm x 4 mm, a thickness of no greater than 0.3 mm for the upper layer and the thickness of no greater than 0.3 mm for the lower layer, and a thickness of no greater than 50 μm for the middle layer.

[0012] In one embodiment, the upper layer, the middle layer and the lower layer are made of the same thermoplastic material, wherein the middle layer thermoplastic material is doped with carbon black.

[0013] In one embodiment, the upper layer, the middle layer and the lower layer are PC, COP or PMMA.

[0014] In one embodiment, the polymer optoelectronic device is an optoelectronic device for a smartphone, and the optoelectronic device unit is a lens module or an image sensor module of the smartphone.

[0015] In one embodiment, the present invention provides a packaging method for a polymer optoelectronic device, characterized in that the method comprises the following steps: Step 1: aligning the upper layer, the middle layer and the lower layer; Step 2: welding the upper layer, the middle layer and the lower layer using a laser, and applying welding pressure to the polymer optoelectronic device with a pressure mechanism before, during and after welding to keep the polymer optoelectronic device flat, and the welding is a single laser welding mode or a dual laser welding mode.

[0016] In one embodiment, the method further comprises: cutting the welded polymer optoelectronic device by laser to obtain optoelectronic device units.

[0017] In one embodiment, in dual laser welding mode, the upper and lower layers are laser welded synchronously and in parallel, so that the stress generated by welding is minimized.

[0018] In one embodiment, quartz substrates are respectively provided on the upper layer and the lower layer, and pressure is applied through the quartz substrates.

[0019] The polymer optoelectronic device, made of thermoplastic materials (e.g., PC, COP, PMMA) and manufactured through a precision injection molding process, is easier to mass-produce and process than conventional optoelectronic devices made from glass materials, resulting in lower product costs, faster production speeds, and greater versatility. Furthermore, polymer optoelectronic devices made from thermoplastic materials are less susceptible to breakage and device failure than those made from glass.

[0020] During the laser welding and packaging process of polymer optoelectronic devices made of thermoplastic materials, plastic stress is generated due to the following reasons: the plastic has poor thermal conductivity, laser welding produces temperature differences; the plastic is thin and easy to bend and deform.

[0021] In the laser welding packaging method of the present invention, all process parameters during the packaging process are precisely controllable. These process parameters include laser movement speed, laser power, laser focal length, laser width, welding pressure, and pressure holding time. This method enables precise, rapid, reliable, and highly uniform mass packaging of micro-nanopolymer optoelectronic devices for use in smartphones. Maintaining a constant pressure before, during, and after welding effectively prevents deformation and bending of the plastic during welding. Furthermore, when dual lasers are used for simultaneous welding, the upper and lower plastics deform synchronously, effectively preventing deformation and bending during welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is a schematic flow chart of a packaging method for a polymer optoelectronic device of the present invention; and

[0024] Figure 2 It is a schematic diagram of the structure of the photoelectric device unit in the lower photoelectric device structure layer of the polymer photoelectric device of the present invention. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions in this application, the present invention will be further described below in conjunction with the following embodiments. Obviously, the embodiments described are only part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of this application. The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] Example: Polymer optoelectronic devices and their packaging process

[0027] like Figure 1 and 2 As shown, the detailed packaging method includes three steps.

[0028] Step 1: Placement and precise alignment of a large-area sandwich structure. Polymer optoelectronic devices consist of three layers: an upper polymer flat sheet, a middle light-absorbing film, and a lower optoelectronic device structural layer. The placement and precise alignment of the sandwich structure are accomplished by inserting it into a customized mechanical tooling ("upper and lower quartz substrate (light-transmitting hard material) tooling"). The upper polymer flat sheet and the lower optoelectronic device structural layer are thermoplastic materials, such as PC, COP, and PMMA. The middle light-absorbing film is a homogeneous film doped with a light-absorbing material, such as PC, COP, or PMMA film material doped with carbon black.

[0029] Step 2: Laser welding of large-area sandwich structures. The welding process includes structural pressure application, laser welding, and structural pressure holding. By precisely controlling laser movement speed, laser power, laser focal length, laser width, welding pressure, and pressure holding time, the weld line width, strength, and uniformity are precisely controlled, reducing weld stress and maintaining the flatness of the optoelectronic device. Two illumination modes are used during the welding process: single laser welding mode and dual laser welding mode. The dual laser welding mode makes process parameters easier to control and reduces weld stress.

[0030] In some embodiments, a 4 cm diameter cylinder is used, the area of the workpiece is approximately 4 cm*6 cm, and the pressure is approximately 0.2 MPa.

[0031] In some embodiments, the laser wavelength used for laser welding is an infrared wavelength, such as 980 nm. The specific laser wavelength can be selected based on the material properties, requiring that the upper and lower transparent materials do not absorb laser energy.

[0032] In some embodiments, the holding time after laser welding is set to 0.5 s.

[0033] In some embodiments, the laser welding power is 300W in total, and the output power is set to 80%.

[0034] Step 3: Laser cutting of large-area sandwich structures. The welded large-area sandwich structures are laser cut to obtain individual micro-nano optoelectronic device units, each with a size of less than 5.0 mm.

[0035] It should be understood that the present invention disclosed is not limited only to the specific method, scheme and material of description, because these all can change.It should also be understood that the term used herein is only for the purpose of describing specific embodiment scheme, rather than being intended to limit the scope of the present invention, and the scope of the present invention is only limited to the appended claims.

[0036] Those skilled in the art will also recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein.Such equivalents are also intended to be encompassed by the appended claims.

Claims

1. A polymer optoelectronic device made of thermoplastic material, characterized in that: The polymer optoelectronic device is encapsulated by three layers of thermoplastic material, the upper layer being a polymer flat sheet, the middle layer being a light-absorbing film, and the lower layer being an optoelectronic device structural layer, wherein the thermal expansion coefficients of the materials of the upper, middle, and lower layers differ by no more than 10%; The upper and lower layers of the three-layer thermoplastic material are capable of transmitting but not absorbing the welding laser, while the middle layer absorbs the welding laser that transmits the upper and / or lower layers so that the three layers are welded and sealed together; and The optoelectronic device structure layer includes no less than 5 optoelectronic device units, each of which is formed in the optoelectronic device structure layer through a precision injection molding process. The size of each optoelectronic device unit is less than 6 mm x 6 mm, the thickness of the upper layer and the lower layer is no more than 0.6 mm, and the thickness of the middle layer is no more than 100 µm; the light-absorbing film in the middle layer is a homogeneous film doped with light-absorbing material.

2. The polymer optoelectronic device according to claim 1, characterized in that The thermal expansion coefficients of the materials of the upper layer, middle layer and lower layer differ by no more than 5%.

3. The polymer optoelectronic device according to claim 2, characterized in that The thermal expansion coefficients of the materials of the upper layer, middle layer and lower layer differ by no more than 3%.

4. The polymer optoelectronic device according to claim 1, characterized in that The size of the upper layer, the middle layer and the lower layer is not less than 1 cm x 1 cm.

5. The polymer optoelectronic device according to claim 1, characterized in that The optoelectronic device unit is a scattered light device with a size of no more than 4 mm x 4 mm, a thickness of no more than 0.3 mm for the upper layer and the lower layer, and a thickness of no more than 50 μm for the middle layer.

6. The polymer optoelectronic device according to claim 1, characterized in that The upper layer, the middle layer and the lower layer are made of the same thermoplastic material, wherein the thermoplastic material of the middle layer is doped with carbon black.

7. The polymer optoelectronic device according to claim 1, characterized in that The upper layer, the middle layer and the lower layer are made of PC, COP or PMMA.

8. The polymer optoelectronic device according to any one of claims 1 to 7, characterized in that: The polymer optoelectronic device is an optoelectronic device for a smartphone, and the optoelectronic device unit is a lens module or an image sensor module of the smartphone.

9. The method for packaging a polymer optoelectronic device according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: Step 1: Align the upper layer, middle layer, and lower layer; Step 2: The upper layer, the middle layer and the lower layer are welded by laser, and welding pressure is applied to the polymer optoelectronic device by a pressure mechanism before, during and after welding to keep the polymer optoelectronic device flat. The welding is performed in a single laser welding mode or a dual laser welding mode.

10. The packaging method of a polymer optoelectronic device according to claim 9, characterized in that: The method further comprises: cutting the welded polymer optoelectronic device by laser to obtain optoelectronic device units.

11. The method for packaging a polymer optoelectronic device according to claim 9, wherein: In dual laser welding mode, the upper and lower layers are laser welded synchronously and in parallel, minimizing the stress generated by welding.

12. The method for packaging a polymer optoelectronic device according to claim 9, wherein: Quartz substrates are respectively arranged on the upper layer and the lower layer, and pressure is applied through the quartz substrates.

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