A pretreatment method and system for improving defects of copper indium gallium selenide photovoltaic flexible assembly

Abstract

The present application relates to the technical field of photovoltaic flexible assembly, and particularly relates to a pretreatment method and system for improving defects of copper indium gallium selenide photovoltaic flexible assembly, which comprises the following steps: step one, welding of chip string; step two, heat pressing of the chip string to expose defective chips; step three, curling test of the heat-pressed chip string to expose damaged chips; and step four, connection of positive and negative electrode lead-out ends of the chip string, light irradiation power generation detection of the chip string, and judgment of whether the chips have defects according to the detection result. The present application sequentially adds the process steps of heat pressing, curling test and chip detection before laying of the photovoltaic flexible assembly, so as to facilitate early identification of defects of the chips and avoid the situation that the chips cannot be replaced after packaging into the assembly.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module technology, and in particular to a pretreatment method and system for improving defects in copper indium gallium selenide (CIGS) photovoltaic flexible modules. Background Technology

[0002] The existing manufacturing process of CIGS flexible modules is as follows: Figure 1 As shown: First, the chip cells are connected in series to form a battery string. Then, encapsulation material is applied. After application, the string is placed in a laminator (high temperature, high pressure) for lamination. After lamination, the module is inspected for defects. Common defects in CIGS flexible modules include the following:

[0003] 1. After the flexible component is rolled up, some chips with defects in the film layer will delaminate or be damaged, resulting in increased resistance and reduced current (because it is a series circuit, the decrease in current of a single chip will lead to current limiting of the entire chip series, and the output power of the component will drop significantly).

[0004] 2. After the battery chips are laminated, local short circuits (burrs, sharp points) may occur under pressure, causing local short circuits and generating high temperatures, which poses a significant safety hazard to the components.

[0005] The existing conventional process involves identifying and judging defective modules at the module testing station. Modules with either of the two types of defects are either downgraded in power (defect 1) or downgraded (defect 2). Defect 1, in particular, has a higher probability of occurrence and causes significant power loss. Using this existing conventional process, if the flexible module already has defects before installation, continuing with subsequent installation and encapsulation not only fails to guarantee the yield of the finished flexible module but also wastes resources in subsequent processes. Therefore, to reduce production losses and improve the yield of finished flexible modules, it is necessary to modify the existing production process to identify defects in photovoltaic modules before installation and encapsulation, thereby facilitating timely improvement of defects in flexible photovoltaic modules. Summary of the Invention

[0006] In view of this, the purpose of this invention is to propose a pretreatment method and system for improving defects in copper indium gallium selenide photovoltaic flexible modules, so as to solve the problem that existing processes cannot detect chip defects in advance.

[0007] To achieve the above objectives, the present invention provides a pretreatment method for improving defects in copper indium gallium selenide (CIGS) photovoltaic flexible modules, comprising the following steps:

[0008] Step 1: Perform chip serial soldering;

[0009] Step 2: Perform thermal pressing on the chip string to expose defective chips;

[0010] Step 3: Perform a curling test on the hot-pressed chip string to expose any damaged chips;

[0011] Step 4: Connect the positive and negative leads of the chip string, perform light-power generation test on the chip string, and determine whether the chip has defects based on the test results.

[0012] Preferably, the hot pressing process parameters in step two are: temperature 130-170℃, pressure 50-100KPa, and pressurization time 30-300s.

[0013] Preferably, in step two, the hot pressing is performed using a laminator, and the contact surfaces of the hot-pressed chip strings are provided with a flexible silicone layer. The flexible silicone layer is made of silicone material (soft and elastic), which, in addition to simulating the laminator environment, also protects the chip surface from damage during the hot pressing process.

[0014] As an optional implementation, the curling test in step three involves setting a suitable roll based on the curvature radius of the photovoltaic flexible module, and setting a flexible silicone layer on the outer surface of the roll, and performing the curling test 1-3 times through the roll.

[0015] Preferably, during the curling test, the light-receiving surface of the chip string faces inward.

[0016] Preferably, in step four, the detection of the chip string is performed by illuminating the light-receiving surface of the chip string with a light source to identify chip defects.

[0017] Optionally, the method for identifying chip defects may employ human eye recognition, infrared detection device recognition, or EL detection device for detection and identification.

[0018] The light source includes halogen lamps and xenon lamps.

[0019] The preprocessing method also includes the steps of laying and laminating the photovoltaic flexible module sequentially after performing light-emitting power generation detection on the chip string.

[0020] The present invention also provides a pretreatment system for improving defects in copper indium gallium selenide photovoltaic flexible modules, including a chip string bonding platform. The pretreatment system further includes a hot pressing device for exposing chip defects, a curling device for testing chip strings to expose chip damage, and a chip testing device for performing light-emitting power generation detection on the chip strings.

[0021] One end of the chip string is vacuum-adsorbed as the starting end of the chip string, and then an automatic winding device is used to wind the chip string.

[0022] The beneficial effects of this invention are as follows: By adding hot-pressing, curling testing, and chip inspection steps sequentially before the installation of flexible photovoltaic modules, this invention facilitates the early identification of chip defects and avoids situations where chips cannot be replaced after the modules are packaged. Specifically, the hot-pressing process exposes chips with hidden defects; the curling test exposes damaged chips; and the chip inspection process identifies chips with serious defects in advance, preventing irreparable damage after module packaging and the resulting reduction in power output and product quality. This improved pre-processing technology reduces production losses and increases the yield rate of flexible photovoltaic modules. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of the conventional process for producing flexible photovoltaic modules.

[0025] Figure 2 This is a process flow diagram of the present invention;

[0026] Figure 3 This is a partial schematic diagram of the preprocessing system of the present invention.

[0027] The diagram is marked as follows:

[0028] 1. Hot pressing device; 2. Chip string; 3. Flexible silicone layer; 4. Roll; 5. Light source; 6. Infrared detection device. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0030] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] like Figure 2 and Figure 3 As shown, a pretreatment method for improving defects in copper indium gallium selenide (CIGS) photovoltaic flexible modules includes the following steps:

[0032] Step 1: Perform chip serial soldering;

[0033] Step 2: Perform thermal pressing on the chip string to expose defective chips;

[0034] Step 3: Perform a curling test on the hot-pressed chip string to expose any damaged chips;

[0035] Step 4: Connect the positive and negative leads of the chip string, perform light-power generation test on the chip string, and determine whether the chip has defects based on the test results;

[0036] Step 5: Lay out the flexible photovoltaic modules;

[0037] Step 6: Lamination and encapsulation.

[0038] Compared to existing conventional processes, this invention adds three steps: chip string hot pressing, chip string curling test, and chip string inspection. Chip string hot pressing simulates laminator packaging conditions to pre-process the battery chip string and expose chips with hidden defects. Chip string curling test simulates the actual use environment of flexible components to expose damaged chips. Chip inspection connects the positive and negative leads of the chip string, allows the photovoltaic chips to generate electricity through illumination, and identifies and judges problematic chips, then replaces severely defective chips. This avoids the regrettable situation where the packaged components cannot be repaired, leading only to power reduction and product downgrading.

[0039] In this invention, different process parameters are used depending on the type of chip, primarily due to the differences in CIGS chip packaging materials. As a preferred embodiment, the hot-pressing process parameters in step two are: temperature 130-170℃, pressure 50-100KPa, and pressurization time 30-300s. To ensure that heavy metal elements in the CIGS chip do not harm human health, a polymer composite material is used for pre-packaging in the final stage of chip manufacturing before the CIGS chip is put into the packaging process. Different application scenarios and different lifespan requirements lead to different pre-packaging materials, which in turn results in process variations. For example, the materials used for 3-year, 10-year, and 25-year warranties are different; the materials used for marine and desert environments also differ significantly (focusing on waterproofing versus resistance to thermal fatigue); there are also differences between military and civilian products, etc.

[0040] The hot pressing process can be performed using a laminator. To prevent damage during hot pressing, a flexible silicone layer is provided on the contact surface of the hot-pressed chip string. The flexible silicone layer is made of silicone material (soft and elastic). During the hot pressing process, in addition to simulating the laminator environment, it also protects the chip surface from damage.

[0041] As an optional implementation, step three, the curling test, involves setting up a suitable roller based on the curvature radius of the flexible photovoltaic module, and applying a flexible silicone layer to the outer surface of the roller. The curling test is then performed 1-3 times. During implementation, the curling test can be performed manually or automatically using a vacuum adsorption structure with holes at the leftmost end of the chip string. This allows the starting end of the chip string to be grasped, and the automatic curling device can then smoothly complete the curling. Preferably, during the curling test, the light-receiving surface of the chip string faces inward. This inward bending method of the CIGS thin-film photovoltaic module makes it easier to expose film defects, which are related to internal stress. This method also makes it easier to expose areas with poor interlayer adhesion earlier. The curling must be performed on the chip string; individual chips cannot be curled. Furthermore, the chip string uses a stacking technology, and some defects occur in the overlapping areas of adjacent chips after stacking. These areas are relatively thick and are prone to film cracking and damage when external pressure is applied.

[0042] In this invention, the roll can be a roll with a fixed diameter, the diameter of which is designed with the radius of curvature based on the flexible component product; this facilitates the simulation of flexible component curling and exposes chip defects in advance. The flexible silicone material layer covering the outer surface of the roll can effectively protect the surface of the chip string and avoid significant compression damage. For flexible components longer than 1 meter, the diameter is 300mm-500mm; for flexible components shorter than 1 meter, the diameter is 500mm-1000mm. The specific selection parameters depend on warranty requirements and application scenarios, with the main considerations being service life and environmental factors with drastic temperature changes.

[0043] In this invention, as a preferred embodiment, the detection of the chip string in step four involves illuminating the illuminated surface of the chip string with a light source to identify chip defects. The method for identifying chip defects can be human eye detection, infrared detection, or EL detection. The light source can be a halogen lamp, xenon lamp, etc. Using a light source (halogen lamp, xenon lamp, etc.) to simulate sunlight, the illuminated surface of the chip string is irradiated for 3-5 seconds. The chip defect is then identified using an infrared detection device. Defect points have higher resistance and are easily heated, making them detectable by the infrared detection device (or human eye). A power supply can be used instead of a light source, and an EL detection device can also be used for infrared detection; relatively speaking, some defects are clearer when detected by infrared. The purpose of using an infrared detection device is to distinguish the temperature differences between normal and abnormal chips (temperature differences are caused by differences in resistance values). The core function is to identify temperature differences; for example, the temperature of a normal chip is generally between 40-70℃, while the temperature of a problematic chip will generally reach above 150℃; a few can even exceed 200℃. Such overheated chips can cause the polymer material outside the flexible component to melt, leading to insulation failure and serious risks.

[0044] As a feasible approach, when a defective chip string is identified, the battery string is powered on, a handheld infrared detector is used to scan the chip string, the chip is identified and marked, and then the chip is replaced.

[0045] The present invention also provides a pretreatment system for improving defects in copper indium gallium selenide (CIGS) photovoltaic flexible modules, including a chip string bonding platform. The pretreatment system further includes a hot pressing device for exposing chip defects, a curling device for testing the chip strings to expose chip damage, and a chip inspection device for performing light-emitting power generation detection on the chip strings. The chip inspection device may employ an infrared thermal imager.

[0046] To facilitate the automatic curling of the chip string, one end of the chip string is vacuum-adsorbed as the starting end, and then an automatic curling device is used to curl the chip string.

[0047] The following examples will illustrate this.

[0048] Example

[0049] A pretreatment method for improving defects in copper indium gallium selenide (CIGS) photovoltaic flexible modules specifically includes the following steps:

[0050] Step 1: String soldering the chips. The string soldering process uses existing technology and will not be described in detail here.

[0051] Step 2: Hot-press the chip string to expose defective chips; use a laminator for hot pressing, and the contact surface of the hot-pressed chip string is equipped with a flexible silicone layer; the hot pressing process parameters are: temperature 150℃, pressure 80KPa, and pressing time 180s.

[0052] Step 3: Perform a curling test on the hot-pressed chip string to expose damaged chips. Specifically, set up a 300mm diameter roll (for desert environments and materials with a 25-year warranty), manually complete the curling, and expose damaged chips by simulating the usage environment of flexible components. Once discovered, replace and process them in a timely manner.

[0053] Step 4: Connect the positive and negative leads of the chip string, and generate electricity through sunlight. Use an infrared detection device to identify and determine faulty chips, then replace severely defective chips. This avoids the regrettable situation where the packaged components are irreparable, requiring only power reduction and product downgrading. In this embodiment, the infrared detection device is a FLIR T911202 infrared thermal imager.

[0054] Step 5: Lay out the flexible photovoltaic modules.

[0055] Step 6: Lamination and encapsulation.

[0056] In actual production applications, this pretreatment method can identify defective chips in advance and replace them to improve the yield of CIGS photovoltaic modules.

[0057] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0058] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A pretreatment method for improving defects in copper indium gallium selenide (CIGS) photovoltaic flexible modules, characterized in that, Includes the following steps: Step 1: Perform chip serial soldering; Step 2: Perform thermal pressing on the chip string to expose defective chips; Step 3: Perform a curling test on the hot-pressed chip string to expose any damaged chips; Step 4: Connect the positive and negative leads of the chip string, perform light-power generation test on the chip string, and determine whether the chip has defects based on the test results; The hot pressing process parameters in step two are: temperature 130-170℃, pressure 50-100KPa, and pressing time 30-300s. In step three, the curling test involves setting a suitable roller based on the curvature radius of the photovoltaic flexible module and setting a flexible silicone layer on the outer surface of the roller. The roller is used to perform the curling test 1-3 times. During the curling test, the light-receiving surface of the chip string faces inward. In step four, the chip string is inspected by illuminating the light-receiving surface of the chip string with a light source to identify chip defects.

2. The pretreatment method for improving defects in copper indium gallium selenide photovoltaic flexible modules according to claim 1, characterized in that, In step two, hot pressing is performed using a laminator, and the contact surface of the hot-pressed chip string is provided with a flexible silicone layer.

3. The pretreatment method for improving defects in copper indium gallium selenide photovoltaic flexible modules according to claim 1, characterized in that, The method for identifying chip defects employs human eye recognition, infrared detection, or EL detection.

4. The pretreatment method for improving defects in copper indium gallium selenide photovoltaic flexible modules according to claim 1, characterized in that, The light source includes halogen lamps and xenon lamps.

5. The pretreatment method for improving defects in copper indium gallium selenide photovoltaic flexible modules according to claim 1, characterized in that, The preprocessing method also includes the steps of laying and laminating the photovoltaic flexible module sequentially after performing light-emitting power generation detection on the chip string.

6. The pretreatment method for improving defects in copper indium gallium selenide photovoltaic flexible modules according to claim 1, characterized in that, The preprocessing method employs a preprocessing system including a chip string bonding platform, which further includes a hot pressing device for exposing chip defects, a curling device for testing the chip string to expose chip damage, and a chip testing device for performing light-emitting power generation detection on the chip string.

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