high fidelity tape transfer printing based on chemically induced adhesive strength modulation - heat transfer printing film
Pad, two-step process (i. e.
Pick up print)
In order to achieve heterogeneous integration, the manufacturing of functional electronic systems has been widely used.
In order to ensure a reliable process, strong pick-up adhesion and weak or no printing adhesion are required.
However, it is a challenge to meet the requirements of switchable stamp bonding.
Here we introduce a simple, hi-fi process, namely, tape transfer printing (TTP)
, Is achieved by chemical-induced vigorous modulation in the adhesive strength of the tape.
We describe the working mechanism of the adhesion modulation that controls this process, and transfer the printing of several types of materials and equipment through Hi-Fi tape, including Si particle array, photoelectric detector array to demonstrate this method and EMGEMG)
Sensors, from their preparation substrate to various foreign substrates.
The high fidelity tape transfer printing of the assembly on the surface of the curve is also shown. Ultra-
Thin Si particle arrays were made using SOI wafers with 1.
25 μm thick top layer of single crystal Si.
Clean the SOI wafer with acetone, IPA and DI water, then bake under 110C for 2 minutes and dehydrate on the hot plate.
An Si square of 250 μm × 250 μm was formed by etching with exposure and reaction ions (RIE).
The wafer is immersed in a buffer oxide etching agent (BOE, 1:6)
Weaken the etching for 15 minutes. Photoresist (PR)
Anchoring is formed by rotating the coating and photography to prevent future floating of Si during subsequent weakening release.
Then completely immerse the Si pellets in the concentrated hf (HF, 49%)
Two hours to remove the remaining SiO, resulting in complete induction under etching. Ultra-
Thin Si-based photoelectric detectors were made using a SOI wafer with a top layer of 1.
25 μm thick single crystal Si.
The main manufacturing steps include selective doping to produce active regions and harvesting thin devices by sacrificing the weakening of buried oxides.
Similar practices have been reported elsewhere.
Specifically, the use of the spin on the glass forms a SiO-doping shield of 600 nm thick on the SOI wafer (
And patterned based on standard exposure and etching.
Because the SOI wafer is p-type (Resistivity: 11. 5u2009Ωu2009cm)
, Phosphorus-based spin-on-dopant (
Used for the doping process at 950 °c to form two n-back-to-back-p-p-n diodes.
The top Si device is patterned into a 250 μm × 250 μm square array by reaction ion etching (RIE)
Use sulfur chloride (SF)gas.
The photoelectric detector is anchored through the anti-photoresist to prevent floating in the hf (
HF, concentration 49%)
Then there is the SiO weakening etching process, similar to the process described in Si Particle Manufacturing.
To prepare the EMG sensor, wash the slides with acetone, IPA and DI water, then bake for 2 min at 110 °c for dehydration.
Then the PI pioneer liquid is coated on the glass by rotation
Casting and film curing at 250 °c for 1 hour.
The Ag layer of 300nm was deposited on PI by electronic deposition method
The beam evaporates.
The electrodes were patterned by photographic and wet etching.
The PI is used as a supporting structure, the pattern is drawn by RIE under O plasma, and the metal electrode is used as a mask.
Using the EMG sensor with 3 M 3850 to pick up the Ag/PI structure from the glass substrate.
Before printing, thin SiO (50nm)
The layer is deposited on the tape by e-
The beam evaporates.
Thin Ecoflex (~500u2009μm)
Rotate the coating on the glass substrate and solidify at 90 °c for 5 minutes.
Since then, the Ecoflex film has been exposed to ultraviolet ozone (UVO)
The treatment of producing oh termination base on the surface of Ecoflex film.
The tape is laminated on the Ecoflex substrate and heated at 70 °c for 10 minutes to form a firm bonded bond between the SiO and Ecoflex substrates on the PI.
In order to retrieve the tape, the sample is immersed in acetone, then the tape is immediately stripped from the substrate and the EMG sensor is left on the thin Ecoflex.
In the form of a thin ribbon cable, the electrode pad connected to one side of the mesh and the ACF on the printed circuit board (PCB)
On the other hand, an electrical connection to an external amplifier is provided for signal acquisition.
At these connection points, the ACF is solidified on a flat iron for 1 minute to form a strong mechanical joint.
Finally, the EMG sensor with ACF cable bonding was carefully stripped from the glass substrate.
The surface of the curve with different radius of curvature is cleaned and coated with thin (
Thickness 100 μ μm)Ecoflex.
After picking up the Si particle array, the adhesive tape is connected consistently with the surface of the curve and follows the transfer printing process.
The measurement of the EMG signal is carried out with the approval of the Institutional Review Committee (
Protocol number: 14139-01)
University of Houston.
All experiments were conducted in accordance with relevant guidelines and regulations.
The theme is a common one.
The author of the paper.
The study was conducted with the subject's informed signing of consent.