Solar Cell Tab Lead Connection and Resin Sealing
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Solution Overview
Problem
The existing manufacturing process for solar cell modules requires separate steps for tab lead connection and resin sealing at different temperatures, leading to increased manufacturing time, handling frequency, and potential stress-induced failures like cracks in solar cells.
Innovation Solution
The method involves using a vacuum laminator with independent pressure control and a heating stage to simultaneously connect tab leads to solar cells and seal with resin at a low temperature, employing a pressurizing film, conductive adhesive films with protruding particles, or thermosetting adhesive layers on tab leads to ensure reliable connections without resin spread.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tab lead connection and resin sealing are performed as separate steps at different temperatures, then connection reliability is improved, but manufacturing time and handling frequency increase
Solution Approach 1:
The patent combines the tab lead connection step and resin sealing step into a single simultaneous operation. The stacked structure includes the solar cell, adhesive layer, tab lead, and resin layer, which are processed together in one heating cycle to achieve both connection and sealing functions simultaneously, thereby reducing manufacturing time and handling frequency while maintaining connection reliability.
2Productivity
If tab lead connection and resin sealing are performed simultaneously at low temperature, then manufacturing time is reduced, but adhesive resin may spread to non-connection areas causing connection failure
Solution Approach 1:
The patent introduces a release paper layer as an intermediary between the adhesive layer and the resin layer. This release paper prevents the resin from directly contacting and spreading to non-connection areas during the simultaneous heating process, while still allowing the adhesive to properly bond the tab lead to the solar cell. The release paper is later removed after serving its protective function.
Solution Approach 2:
The release paper functions as a thin film barrier that controls resin flow during the heating process. This thin film structure allows the resin to be contained within the connection area while permitting the necessary thermal and pressure transmission for adhesive bonding to occur simultaneously.
3Strength
If high temperature is used for tab lead connection, then connection strength is improved, but internal stress accumulates in solar cells causing cracks
Solution Approach 1:
The patent changes the temperature parameter from high temperature (240°C or higher) to low temperature (about 150°C) by using a low-melting-point adhesive material. This parameter change allows the tab lead connection to be formed at a temperature that does not cause significant internal stress accumulation in the solar cell, thereby preventing cracks while still achieving reliable connection strength.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for reliable thermo-compression bonding of tab leads and resin sealing at a low temperature, reducing manufacturing costs and stress on solar cells, while maintaining connection reliability and efficiency.
Implementation Method 1
a vacuum laminator including a pressure-reducing unit and a heating plate when thermo-compression bonding is performed
Implementation Method 2
a heating plate when thermo-compression bonding is performed
Implementation Method 3
a pressure-reducing unit and a heating plate when thermo-compression bonding is performed
Data Source
AI summary
In manufacturing of a solar cell module in which a solar cell having a surface electrode to which a tab lead is connected is sealed with a resin, the step of connecting the tab lead and the step of sealing the solar cell with the resin are performed simultaneously at a relatively low temperature that is used for the resin sealing step. To perform these steps simultaneously, the solar cell having the surface electrode to which the tab lead is connected with an adhesive is resin-sealed using a vacuum laminator to manufacture the solar cell module. The vacuum laminator used includes a first chamber and a second chamber partitioned by a flexible sheet. The internal pressures of these chambers can be controlled independently, and a heating stage for heating is provided in the second chamber.