Induction Bonding Solar Panel

Induction Bonding Solar Panel With High Frequency Heating System

Quick Answer

Induction bonding of solar panel shingles heats the stainless steel substrate of the shingle, and that heat melts the polymer encapsulant. The melted encapsulant bonds two overlapping shingles together. In the HLQ case, a 3″ × 10.25″ section of a 21″ solar panel shingle was bonded at a 3″ overlap at 130 °C. The equipment was a DW-UHF-4.5kW (300 kHz as stated) with a custom 4-turn coil of 1/4″ × 1/2″ rectangular copper tubing measuring 24″ × 2 1/4″. The water-cooled coil sat on the topside of the sample for stationary heating and was pressed against the shingle to apply bonding pressure. The tests gave excellent bond formation with no encapsulant bubbling and only a slight change in surface texture.

Table of Contents

What is Induction Bonding of Solar Panels?

Induction bonding of solar panels uses an induction coil to heat the metal substrate inside a solar panel shingle. The polymer encapsulant in contact with the hot substrate melts, so two overlapping shingles bond together. The polymer is not heated by the coil directly; only the stainless steel substrate is. The same principle is used in induction bonding plastic and other polymer-to-metal joints.

Induction bonding solar panel: encapsulated coil pressed on the shingle on a wood surface

Key Applications

HLQ solar panel, polymer and rubber induction bonding cases compared by temperature, time, frequency and equipment

HLQ case Temperature Time Frequency Equipment
Solar panel shingle overlap (this page) 130 °C Several time-voltage settings tested 300 kHz (as stated) DW-UHF-4.5kW
Solar flex circuit soldering 500 °F (260 °C) 10 s 278 kHz (as stated) DW-UHF-4.5kW
Metal braid in plastic catheter tube 250 °F (121 °C) 3.5 s 306 kHz (as stated) DW-UHF-4.5kW
Steel clips into rubber seals 250–350 °F (121–177 °C) 1.5 s 400 kHz (as stated) DW-UHF-4.5kW
Rubber gaskets to steel gas tank 320 °F (160 °C) 6.5 s 200 / 231 kHz DW-UHF-10kW

Suitable Materials

Metal part (heated) Polymer / non-metal (bonded) HLQ source
Stainless steel substrate of a solar panel shingle Polymer encapsulant This page
Wires on solar flex circuits Solder Plus Paste 63NC-A (soldering) Solar panel soldering case
Steel gas tank assembly Rubber gaskets Rubber-to-steel case
Metal braid Plastic catheter tube Catheter tube case

Working Principle

Induction bonding solar panel principle: coil on the 3 in shingle overlap heats the stainless steel substrate and melts the polymer encapsulant

The DW-UHF-4.5kW feeds a remote heat station containing one 0.66 µF capacitor. The station drives a custom coil of 4 turns of 1/4″ × 1/2″ rectangular copper tubing, measuring 24″ × 2 1/4″. With the coil on the topside of the 3″ overlap, the stainless steel substrate is heated in place (stationary heating) until the polymer encapsulant melts at 130 °C. The water-cooled coil is pressed against the shingle at the same time, which helps the bond form. For coil options, see induction heating coil design.

Technical Specifications

Parameter HLQ case data
Objective To heat the stainless steel substrate of a solar panel shingle in order to melt the polymer encapsulant, allowing two shingles to bond together with a 3″ (76.2 mm) overlap
Material 3″ × 10.25″ (76.2 × 260.35 mm) section of a 21″ (533.4 mm) solar panel shingle
Temperature 130 °C
Frequency 300 kHz (as stated)
Equipment DW-UHF-4.5kW power supply with a remote heat station containing one 0.66 µF capacitor
Coil Custom-made: 4 turns of 1/4″ × 1/2″ (6.35 × 12.7 mm) rectangular copper tubing, measuring 24″ × 2 1/4″ (609.6 × 57.15 mm)
Heating method Stationary heating with the coil on the topside of the sample
Pressure Applied by pressing the water-cooled coil against the shingle
Test settings Several time-voltage settings
Results Excellent bond formation with the absence of encapsulant bubbling and only slight surface texture change

Recommended Model Selection

DW-UHF series data from the HLQ model table (100% duty cycle):

Model Power Max. input current Frequency Supply HLQ case
DW-UHF-4.5kW 4.5 kW 20 A 1.1–2.0 MHz 1-phase 220 V Solar panel shingle (case states 300 kHz); solar flex circuits (case states 278 kHz)
DW-UHF-6.0kW 6.0 kW 28 A 300–1100 kHz 1-phase 220 V –
DW-UHF-10kW 10 kW 15 A 100–500 kHz 3-phase 380 V Rubber gaskets to steel gas tank

Process Workflow

Solar shingle induction bonding process workflow

  1. Coil – a custom 4-turn coil of 1/4″ × 1/2″ rectangular copper tubing, 24″ × 2 1/4″.
  2. Overlap – the shingles are overlapped by 3″ according to requirements.
  3. Support – the shingles are placed on wood to simulate installation on a roofing surface.
  4. Coil on top – the water-cooled coil is placed on the topside of the sample and pressed against the shingle.
  5. Heat – stationary heating brings the stainless steel substrate to 130 °C.
  6. Settings – tests are performed at several time-voltage settings.
  7. Bond – the polymer encapsulant melts, giving uniform melt and adhesion.

Solar shingle bonding station layout with DW-UHF-4.5kW, remote heat station, water-cooled coil and wood support

Common Problems and Solutions

Problem Cause Solution (HLQ data)
Non-uniform melt Moving or uneven heating Stationary heating with the coil on the topside of the sample
Weak adhesion No contact pressure during melting Pressure applied by pressing the water-cooled coil against the shingle
Encapsulant bubbling Unsuitable heating settings Tests at several time-voltage settings; no bubbling in the HLQ result
Surface damage Excess heat Only slight surface texture change at the tested settings
Results differ from field installation Unrealistic test support Shingles placed on wood to simulate a roofing surface

Engineering Selection Guide

  • Solar shingle overlap bonding: DW-UHF-4.5kW (single-phase 220 V) with a coil sized to the overlap, as in the HLQ case.
  • Coil: a rectangular-tube coil matched to the overlap length (24″ × 2 1/4″ in the case) that can also apply pressure.
  • Temperature: the melting temperature of the encapsulant (130 °C in the case).
  • Settings: establish the time and voltage by testing on samples.
  • Data to send: panel or shingle construction, substrate metal, encapsulant, overlap size, temperature and cycle time.

Advantages and Limitations

Advantages Limitations
Excellent bond formation Requires a metal substrate in the shingle
No encapsulant bubbling Time and voltage must be set by testing
Only slight surface texture change The coil must be sized to the overlap
The water-cooled coil also applies the bonding pressure Water cooling is required

Why Choose HLQ?

  • Published solar panel bonding and soldering data.
  • Custom coils, including long rectangular-tube coils.
  • Compact single-phase DW-UHF systems.
  • Experience with polymer, rubber and plastic bonding to metal.

10 Core FAQs

1. What was bonded?

Two solar panel shingles, bonded together with a 3″ overlap.

2. What is heated by induction?

The stainless steel substrate of the shingle; its heat melts the polymer encapsulant.

3. What temperature is used?

130 °C.

4. What sample was tested?

A 3″ × 10.25″ section of a 21″ solar panel shingle.

5. Which equipment was used?

A DW-UHF-4.5kW power supply with a remote heat station containing one 0.66 µF capacitor, at 300 kHz as stated.

6. Which coil was used?

A custom-made coil of 4 turns of 1/4″ × 1/2″ rectangular copper tubing, measuring 24″ × 2 1/4″.

7. How is pressure applied?

The water-cooled coil is pressed against the shingle.

8. Why were the shingles placed on wood?

To simulate installation on a roofing surface.

9. What was the result?

Excellent bond formation, no encapsulant bubbling and only slight surface texture change.

10. What information is needed for a quotation?

Panel or shingle construction, substrate metal, encapsulant, overlap size, temperature and cycle time.

HLQ-Induction-Bonding-Solar-Panel-Brochure

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