1. LPKF Laser Direct Structuring System
Speciality Products and Services Group
Electrical functionalisation of non conductive 3D Structures
Electrical tracks produced on 3D structures - allowing SMT assembly, die attach, wire bonding etc.
LPKF – Laser Direct Structuring
of 3D devices.
Metallised Fingers for Robotic Hand

2. LPKF Laser Direct Structuring System
Tyndall Fabrication Process
3D Design and drawing.
3D part fabrication.
Conductive layer design and drawing.
Part Coating – ProtoPaint epoxy layer.
Laser Direct structuring as per design.
Copper plating
Post processing – NiAu plating, Flip chip bonding, SMT, wire bonding etc.

3. LPKF Laser Direct Structuring System
Fabrication Principle

4. LPKF Laser Direct Structuring System
3D Design
In-house 3D design of parts
Autocad used to produce .step files which can be imported to LPKF system.
Autocad used to produce .dwg files for fabrication in mechanical workshop.

5. LPKF Laser Direct Structuring System
3D Part Fabrication
In-house mechanical workshop fabrication from 3D designs.
Parts fabricated from metals or plastic materials.
3D designs can be used to fabricate parts using standard 3D printers

6. LPKF Laser Direct Structuring System
Conductive layer design
Autocad produces .stp files with both the 3D part and associated conductive layer.
LPKF system used .stp file to laser write the conductive layer on a ProtoPaint epoxy layer which is applied to 3D part surface.

7. LPKF Laser Direct Structuring System
Part Coating – ProtoPaint epoxy layer.
Spray coating of 3D part surface.
Multiple layer build up to produce a smooth surface finish.
Low temperature oven bake to cure epoxy.
Coating on conductive and non conductive materials.
Possible materials include metals, plastics, glass, FR4 etc.

8. LPKF Laser Direct Structuring System
Laser Direct Structuring – Laser writing
LPKF system laser etches the conductor design in the top surface of the ProtoPaint epoxy.
The laser removes some of the epoxy material exposing metal particles in the ProtoPaint layer.
These metal particles can act as a seed layer for deposition of Cu layer.

9. LPKF Laser Direct Structuring System
Laser Direct Structuring – Protopaint
Metal particles exposed by the laser
Copper, palladium, Chromium and Magnesium Seed Layer

10. LPKF Laser Direct Structuring System
Copper plating
Electroless copper plating of seed layer exposed by laser etching of the ProtoPaint top surface.
Layer thickness is a time-temperature dependent build up of copper.

11. LPKF Laser Direct Structuring System
Copper plating

12. LPKF Laser Direct Structuring System
Copper plating
Test coupons used to check track resistance and isolation between tracks.
Different track and gap widths were designed to look at the effect of this on electrical measurements.
Typical track resistance of <1 ohm
Typical isolation of > 2K ohm
Part Type
Plating Thickness
Track Resistance Ω
Fingers Resistance Ω
200 µm TG
9 µm
0.8
Open Circuit >2000
0.9
1.0
500 µm TG
5 µm
0.5
100 µm TG
6 µm
0.6
3 µm
1.4

13. LPKF Laser Direct Structuring System
Post Processing - Solder
Copper plating provides a solderable finish
Allowing post process SMT assembly, solder flip chip etc.
Solder ball Placement
Element ID
size x (um)
size y (um)
SIZE X (inch)
SIZE Y (inch)
Area 10-4 (inch square)
Mil-883-J Requirement (Kg)
Measured Shear Force (Kg)
SMT 1
1200
500
0.0472
0.0197
9.30
0.37
3.12
SMT 2
2.72
SMT 3
4.12
SMT 4
3.08

14. LPKF Laser Direct Structuring System
Post Processing - Solder
Solderable finish allows for in house Laser Assisted Solder Jetting (SB²)

15. LPKF Laser Direct Structuring System
Post Processing - NiAu Plating
NiAu Plating on the copper surface
Increased solderability
Wire bondable finish
Bond
No.
Strength
(gf)
Military Standard (gf)
(1)
5.35
3.00
(2)
6.45
(3)
8.30
(4)
4.55
(5)
5.90
(6)
5.65
(7)
9.10
(8)
4.95
(9)
5.15
(10)
6.20

16. LPKF Laser Direct Structuring System
Post Processing - NiAu Plating

17. LPKF Laser Direct Structuring System
Post Processing - NiAu Plating – Assisted Solder Jetting (SB²)

18. Demonstrator 1 – Antenna on housing
LPKF Laser Direct Structuring System
Demonstrator 1 – Antenna on housing
Antenna fabricated directly on surface of 3D printed component housing.

19. Demonstrator 2 – Chemical Sensor
LPKF Laser Direct Structuring System
Demonstrator 2 – Chemical Sensor
PCB Equivalents
Flip chip over hole based micro electrode chemical sensor
3D substrate Demonstrator
Silicon based Micro electrode arrays.
Complete Design and Fabrication in Tyndall
Machined plastic substrate
Silicon Sensor die

20. Demonstrator 2 – Chemical Sensor
LPKF Laser Direct Structuring System
Demonstrator 2 – Chemical Sensor
Electrodes
Protopaint application
Laser Patterning
Copper plating
Machined plastic substrate
Solder flip chip
Underfill sealing of sensor

21. Email: ken.rodgers@tyndall.ie Email: finbarr.waldron@tyndall.ie
LPKF Laser Direct Structuring System
Contact Information
Ken Rodgers
Phone:
Finbarr Waldron
Phone: