Name: LOCTITE ABLESTIK ATB 120U
Brand: Henkel Belgium NV
SKU: ABLESTIK ATB120U

Main features

Non conductive
Thin bondline
Fast cure

Product Description

LOCTITE® ABLESTIK ATB 120U Non conductive adhesive film is formulated for use in wafer lamination and chip on chip processes. It combines process ease with the proven reliability of Henkel materials. It is the most transparent film available for high volume applications and is widely used for glass attach in smart phones (bonding the finger print sensor “under glass”).This 2 in 1 format is designed for base die and die to die (>1x1mm) applications, moving to thing wafer (<100um). It is a product with good workability, excellent flow ability on the substrate and a good candidate when using a Si spacer die for CoC processes.

LOCTITE® ABLESTIK ATB 120U Non conductive adhesive film has a thickness of 20um but is also available in 10, 30 and 40um. It can be used to absorb CTE mismatch between substrates but the extend to which it can be effective will depend on the bond area. The bigger the parts, the bigger the mismatch and stress. Even flexible adhesives won’t behave that flexible when thin bond lines need to absorb stress in larger bond areas. For example the glass wind shield in cars is bonded with flexible PUR adhesive with ±2-3mm bond line thickness to absorb movements. So from a Die attach film perspective, a 20um bond line will give half the stress compared to 10um!

LOCTITE® ABLESTIK ATB 120U is a medium modulus die attach film on dicing tape with 20um transparent thermoset epoxy layer that is DBG (Dicing before grinding) compatible. This means that (contrary to the "normal" process) the wafer is half cutted and the die separation happens during the backside grinding process.

Cure Schedule

30 minute ramp to 120°C + 30 minutes @ 120°C

Packaging

Please select Package Type and Pieces per roll.

LINQPAKInsulatedboxesforCooledSupplyChainTransport

English (Packaging & logistics)

TDS, SDS & Technical Documents

Technical Specifications

General Properties

Adhesive Thickness

20 µm

Film Thickness

85 µm

Total Thickness

105 μm

Work life @25°C

720 hours

Thermal Properties

Thermal Conductivity

0.21 W/m.K

Additional Information

Transparent non-conductive die attach film

LOCTITE ABLESTIK ATB 120U

LOCTITE ABLESTIK ATB 120U is a transparent, non-conductive rubberized epoxy die attach film for wafer lamination and die-to-die stacking. The standard construction uses a 20 um adhesive layer on an 85 um polyolefin carrier for 8 in and 12 in wafers. It is also positioned for glass-to-IC attach in fingerprint sensor assemblies, where optical transmission and controlled thin bondline geometry are important evaluation factors.

TransparentNon-conductive20 um adhesive film8 in and 12 in wafersGap filling abilityL2/260C performance

Application and format

Built for wafer-level film handling and stacked-die assembly

ATB 120U combines a dry film format with a transparent thermoset adhesive layer. The supplied construction supports controlled wafer lamination, die pickup, and subsequent chip attach while keeping the adhesive thickness defined before final cure.

Wafer lamination and die attach

Formulated for wafer lamination processes with a 20 um adhesive layer on an 85 um polyolefin carrier. The standard film is available for 8 in and 12 in wafers.

Die-to-die and chip-on-chip

The documented package application is die-to-die stacking. The film is also used in base-die and die-to-die parts above 1 x 1 mm and can be evaluated in chip-on-chip flows with thin wafers below 100 um, including Si spacer die configurations.

Fingerprint sensor glass attach

Henkel positions ATB 120U for glass-to-IC attach in fingerprint sensor assemblies, providing a transparent film option for bonding glass to the sensor-die stack.

Bondline design note: The 20 um film thickness is one mechanical design variable when substrates have different CTEs. Actual joint stress also depends on bond area, substrate properties, adhesive modulus, geometry, and thermal excursion. Related ATB film formats are available in 10, 30, and 40 um adhesive thicknesses; validate the selected thickness in the intended assembly.

Processing

Wafer lamination, chip attach, and heat cure

The process window below preserves the documented ATB 120U lamination, attach, and cure conditions. These are guideline conditions and should be validated with the actual wafer, die geometry, equipment, oven loading, and assembly flow.

Wafer backside lamination
65 to 70 degC
40 psi
1 ft/min

Chip attach
100 to 120 degC
0.5 to 2 kg-f
1 to 2 seconds

Primary cure
30 minute ramp to 120 degC
then 30 minutes at 120 degC

Alternate cure
30 minute ramp to 90 degC + 30 minutes at 90 degC + 30 minute ramp to 120 degC + 30 minutes at 120 degC

Dicing Before Grinding compatibility: ATB 120U can be used in DBG workflows in which the wafer is partially diced before backside grinding and final die separation occurs during grinding. Confirm the dicing depth, grinding process, film handling, die pickup, and downstream cure with the actual wafer construction.

Storage and handling

Protect the film from moisture and contamination

Optimal storage: 5 degC. Keep unused film in the original sealed moisture-resistant package until needed. Partially used reels should be stored under dry conditions at 5 degC. Material removed from the package can become contaminated during use and should not be returned to the original container. Work life is 30 days at 25 degC; shelf life from date of manufacture is 274 days at 5 degC.

Optical performance evidence

ATB 120U transmittance compared with other ATB films

The supplied comparison evaluates optical transmission across infrared, red, orange, yellow, green, blue, and purple wavelength bands for bare glass and several ATB films before cure, after cure, and after cure plus 8 hours at 175 degC.

ATB 120U optical transmittance comparison with other Henkel ATB films before cure, after cure, and after cure plus 8 hours at 175 degC — ATB 120U transmittance versus selected ATB films across wavelength bands and processing states.

What the comparison means

Within the displayed comparison, ATB 120U remains among the highest-transmission films across most longer-wavelength bands before cure, after cure, and after the stated 175 degC thermal exposure. The largest differences between films appear in the blue and purple regions, where transmission is more sensitive to formulation and conditioning.

For fingerprint sensor stacks, this supports evaluating ATB 120U when the adhesive lies in the optical path. The chart is comparative performance evidence for the specific films, wavelength bands, and conditions shown. It does not establish a universal optical specification for every film thickness, glass construction, cure profile, or sensor design.

Important limitation: The supplied evidence does not include ATB 120US2 in this optical comparison, so no ATB 120U versus ATB 120US2 optical ranking is made.

ATB 120U transmittance by visible wavelength band

Exact values below are taken from the supplied ATB 120U wavelength table. The table image does not state specimen thickness, cure state, or measurement method.

Wavelength band	Range	ATB 120U transmittance
Red	610-700 nm	95.71%
Orange	590-610 nm	94.98%
Yellow	570-590 nm	94.01%
Green	500-570 nm	86.61%
Blue	450-500 nm	73.69%
Purple	400-450 nm	46.58%

Data-use disclaimer: These transmittance values and comparative plots are performance data under the conditions associated with the supplied evidence. They are not guaranteed product specifications. Customers should validate optical transmission through the actual adhesive thickness, glass stack, cure profile, wavelength range, sensor architecture, and environmental conditioning used in production.

ATB film optical comparison

How transmission changes across related ATB film grades

The six supplied spectral plots compare transmission versus wavelength after cure and after the environmental or thermal conditions shown in each graph, including 1000 hours at 125 degC, 1000 hours at 85 degC/85% RH, MSL3, and TC1000. The plots are arranged in two fixed rows of three so the grades can be compared visually without separating the graph from its interpretation.

U grades

ATB 110U

High transmission is retained through much of the visible and near-infrared region. The largest condition-related change is concentrated near the short-wavelength transmission edge, so blue and near-UV performance should be checked at the wavelength used by the optical path.

ATB 120U

ATB 120U retains high transmission at longer visible and near-infrared wavelengths across the displayed conditions. The stronger change occurs near the short-wavelength edge, so transmission should be validated at the actual sensor wavelength and after the intended reliability exposure.

ATB 130U

ATB 130U also retains high transmission at longer visible and near-infrared wavelengths, while the condition-to-condition spread becomes more pronounced toward the blue and near-UV edge. Use the graph as grade-specific comparative evidence under the displayed conditions.

US grades

ATB 110US

The plot shows strong transmission through the longer visible and near-infrared region. Condition-related separation is concentrated closer to the short-wavelength edge, making the actual operating wavelength an important selection input.

ATB 120US

ATB 120US shows high transmission through the longer visible and near-infrared region, with larger aging-related movement near the short-wavelength edge. ATB 120US is a different commercial grade from ATB 120US2 and is not optical evidence for ATB 120US2.

ATB 125US

ATB 125US shows the same broad pattern of strong longer-wavelength transmission with greater condition sensitivity near the short-wavelength edge. The curve should remain tied to the conditions and grade identified in the graph.

How to use the comparison: Compare the position and movement of the short-wavelength transmission edge, not only the high-transmission plateau. The graphs are qualitative comparative evidence, so exact values should not be reconstructed from curve positions. ATB 120US and ATB 120US2 are different commercial grades.

ATB 120U versus ATB 120US2

Two 20 um transparent films with different process strategies

ATB 120U and ATB 120US2 share transparent 20 um adhesive-film formats on 85 um polyolefin carriers for 8 in and 12 in wafers, but their documented cure and handling windows are different. Use the comparison below to separate process-relevant differences from optical evidence.

Property or process	ATB 120U	ATB 120US2	Evaluation note
Technology	Rubberized epoxy	Epoxy film	Both are adhesive film technologies, but the TDS descriptions differ.
Appearance	Transparent	Transparent	Appearance alone does not establish equal spectral transmission.
Adhesive / carrier thickness	20 um / 85 um	20 um / 85 um	Same nominal thickness values in the supplied TDSs.
Wafer size	8 in and 12 in	8 in and 12 in	Both support the documented wafer sizes.
Cure strategy	30 minute ramp to 120 degC + 30 minutes at 120 degC	Skip-cure; cured at post-mold cure	This is the clearest process-level difference between the two films.
Work life at 25 degC	30 days	90 days	US2 has the longer documented work-life window.
Shelf life at 5 degC	274 days	365 days	US2 has the longer documented shelf-life window.
Wafer backside lamination	65 to 70 degC; 40 psi; 1 ft/min	65 degC; 30 psi; 1 ft/min	Process settings are similar in structure but not identical.
Chip attach	100 to 120 degC; 0.5 to 2 kg-f; 1 to 2 s	100 to 130 degC; 0.5 to 1.0 kg-f; 0.5 to 1.0 s	US2 has a broader listed attach-temperature range and shorter listed attach duration.
Tg	75 degC by TMA	41 degC by DMTA	Different test methods are reported, so treat this as contextual data rather than an apples-to-apples ranking.
CTE below Tg	62 ppm/degC	81 ppm/degC by TMA	Use with the actual bond area, stack geometry, and temperature range.
Tensile modulus at 25 degC	875 N/mm2 by DMTA	1,277 N/mm2 by DMTA	ATB 120U has the lower listed room-temperature modulus in these datasets.
Moisture absorption at saturation	1.5 wt.% at 85 degC/85% RH	1.8 wt.% after 85 degC/85% RH exposure	Values are close but should remain tied to their respective source wording and conditions.
Thermal budget at 175 degC	Not reported in supplied ATB 120U TDS	>4 hours	Do not infer an ATB 120U thermal-budget value from other tests.
Optical transmission evidence supplied	ATB 120U optical comparison and spectral plots supplied	No directly comparable ATB 120US2 optical dataset supplied	No direct optical ranking is made on this page.

Process strategy trade-offs

Cure versus skip-cure assembly flow

The dedicated-cure and skip-cure approaches trade assembly time against process robustness at different stages. ATB 120U represents the dedicated-cure approach. ATB 120US2 is documented as a skip-cure film that is cured during post-mold cure.

Cure process

Example: ATB 120U

Advantages

Good dicing
Good gap filling
No deferred-cure thermal-budget concern

Process considerations

Longer assembly process time
Potential non-wetting on large die
Suck-back and overflow risk
Relatively higher warpage after cure

Skip-cure process

Example supplied: ATB 120US; ATB 120US2 is also documented as skip-cure

Advantages

Relatively high UPH because pre-bake and separate cure can be skipped
Broad die-attach process window
Easy die stacking

Process considerations

Potential wire-bonding issues, including NSOP or die shift
Higher risk of EMC penetration
Thermal-budget concern for multi-die stacking

Application note: These are process-level trade-offs. Their significance depends on die size, stack architecture, wire-bond sequence, molding compound, thermal exposure, and the actual assembly window, so the final process should be validated on the intended package.

Selection takeaway: ATB 120U uses a dedicated heat-cure sequence and has supplied optical evidence for fingerprint-sensor glass-attach evaluation. ATB 120US2 is designed around a skip-cure process with cure during post-mold cure, with a 90-day work life, 365-day shelf life, and a documented thermal budget greater than 4 hours at 175 degC. Compare the films on the actual assembly flow and required optical, mechanical, and reliability conditions.

Cured material properties

Mechanical, thermal, ionic, and moisture data

The following values are typical cured-material data and performance results for ATB 120U. Preserve the stated method, temperature, specimen, and conditioning when using these values for design screening.

Property	Value	Unit	Method / condition
Glass transition temperature	75	degC	TMA
CTE below Tg	62	ppm/degC	Cured material
CTE above Tg	238	ppm/degC	Cured material
Thermal conductivity	0.21	W/(m-K)	Cured material
Tensile modulus at -65 degC	2,330	N/mm2	DMTA
Tensile modulus at 25 degC	875	N/mm2	DMTA
Tensile modulus at 100 degC	40	N/mm2	DMTA
Tensile modulus at 150 degC	3.0	N/mm2	DMTA
Tensile modulus at 200 degC	1.0	N/mm2	DMTA
Tensile modulus at 250 degC	2.0	N/mm2	DMTA
Extractable ions: Cl-, F-, Na+, K+	<10 each	ppm	Cured material
Weight loss	<1	%	At 300 degC
Moisture absorption at saturation	1.5	wt.%	85 degC/85% RH
Die shear strength at 25 degC	40	kg-f	2.5 x 2.5 mm Si die frontside
Die shear strength at 260 degC	2	kg-f	2.5 x 2.5 mm Si die frontside

Typical data are reference values, not guaranteed product specifications. Package-level performance depends on the actual substrates, interfaces, bondline, die size, cure, conditioning, and test method.

Technical guidance

Translate film data into the actual package stack

Bondline and CTE mismatch

A thicker adhesive layer can provide more compliance for relative substrate movement, but stress does not scale universally with thickness alone. Bond area, die and substrate CTE, modulus, geometry, cure shrinkage, and temperature excursion all affect the final joint.

Optical validation window

Transmission is wavelength dependent and can change with thermal or environmental conditioning, especially near the short-wavelength edge. Validate the actual glass, adhesive thickness, cure profile, sensor wavelength, and aging conditions rather than relying on one averaged visible-transmission number.

ATB 120U versus US2

Use ATB 120U and ATB 120US2 as separate product records. The available US2 data support its skip-cure and thermal-budget positioning, but no directly comparable US2 optical curve is supplied here. Do not use the ATB 120US graph as a substitute for ATB 120US2 data.

Product evaluation support

Evaluate ATB 120U for your die attach stack

Krayden can help review ATB 120U film thickness, wafer-lamination and attach conditions, optical requirements, DBG or thin-wafer process considerations, and differences versus ATB 120US2 or other related ATB films. Use your actual die, glass, substrate, cure flow, wavelength range, and reliability requirements to define the validation plan.