Liquid Encapsulants

Encapsulants for electrical insulation and mechanical protection

AVAILABLE DIRECTLY AT CAPLINQ.COM

Liquid Encapsulants Underfills Optically Clear Materials Wafer Level Packaging

The table below gives a quick overview of our current leading products for liquid encapsulation. Please scroll below for the entire encapsulation range.

Leading Encapsulant Adhesives
	FIL7010C	FP 4470	FP 4450HF	FP4802	FP 4651	FP 4653	FP 4451TD	DAM 7010C
Color	Black	Black	Black	Black	Black	Black	Black	Black
Viscosity	25,000	42,000	32,000	80,000	>100,000	>100,000	300,000	92,500
Silica Filler %	80	75	73	72	82	86	73	80
Max filler size, um	120	50	25	50	50	75	200	120
SVHC	FREE	YES	YES	FREE	YES	YES	YES	FREE
Ionics level, ppm	<10	<2	<2	<5	<5	<10	<10	<10
Tg by TMA, °C	135 - 145	148	164	50	150	150	150	135 - 145
CTE1	16	18	21	20	11	7	21	16
CTE2	58	65	72	100	50	NA	65	63
Cure time, min(2 steps)	60 + 60	30 + 90	30 + 90	30 + 90	60 + 90	150 + 150	30 + 90	60 + 60
Cure temperature °C	100 + 150	125 + 165	125 + 165	125 + 165	125 + 165	110 + 150	125 + 165	100 + 150
Pot life at 25°C	1	3	4	0.33	2	1	10	1
Shelf life at -40°c, months	6	9	9	9	9	9	9	6
Encapsulant Type	FILL					DAM

Encapsulant Adhesives
Product	Apps and Attributes	Viscosity at 25°C (mPa.s)	Filler Type (Content)	Max Filler Size, um	Hardener type	Tg by TMA (°C)	CTE α1(ppm/°C)	CTE α2(ppm/°C)	Cure time (min)	Cure Temp °C
Dam
Loctite ECCOBOND 7010C DAM	Protection of bare IC, Well defined height	92,500	Silica (80%)	120	SVHC free	140	16	63	60 - 60	100 + 150
Loctite ECCOBOND EO 7029	Smartcard encapsulation and die attach	48,000	-	-	-	110	66	181	5	150
Loctite ECCOBOND FP4451TD	BGA and memory encapsulation. Highest aspect ratio for Tall Dam	300,000	Silica (73%)	200	Anhydride	150	21	65	30 + 90	125+165
Loctite ECCOBOND FP4451	Discontinued - No longer available	300,000	Silica (72%)	-	Anhydride	155	22	-	30 + 90	125+165
Fill
Loctite ECCOBOND 7010C FIL	Potting or encapsulation protection for stress sensitive components	25,000	Silica (80%)	120	SVHC free	140	16	58	60 + 60	100 + 150
Loctite ECCOBOND FP0087	Stress-sensitive devices and severe automotive environments	20,000 at 20 rpm	Silica (76%)	N/A	Anhydride	175	18	69	60 + 60	125 + 180
Loctite ECCOBOND FP4450	Discontinued - No longer available	44,000	Silica (73%)	120	Anhydride	155	22	72	30 + 90	125+165
Loctite ECCOBOND FP4450HF	Automotive, BGA, memory, COB, SIP and SmartCard	32,000 at 20 rpm	Silica (73%)	25	Anhydride	164	19	71	30 + 90	125+165
Loctite ECCOBOND FP4470	BGA, CSP, and full array on low temperature co-fired ceramic (LTCC)	48,000	Silica (75%)	50	Anhydride	148	18	65	30 + 90	125+165
Loctite ECCOBOND FP4650	High purity and low thermal expansion	325,000	Silica (83%)	-	-	140	15	-	60 + 120	120 + 160
Loctite ECCOBOND FP4651	Automotive, BGA, memory, COB, SIP, SmartCard and chip array ceramic packages	130,000 at 20 rpm	Silica (82%)	50	Anhydride	150	12	50	60 + 90	125+165
Locite ECCOBOND FP4653	Chocolate breakable on pre-scored ceramic substrate	85,000	Silica (86%)	-	-	150	7	-	120 + 120	110 + 150
Loctite ECCOBOND FP4654	Discontinued - No longer available	32,000 at 20 rpm	Silica (80%)	50	Anhydride	146	13	53	30 + 90	125+165
Loctite ECCOBOND FP4802	BGA, CSP and full array on low temperature co-fired ceramic (LTCC)	80,000 at 10 rpm	Silica (72%)	50	Phenolic	50	20	100	30 + 90	125+165
Loctite STYCAST A316-48	Automotive grade potting material with High Tg for sensors and control modules	50,000	Oxide	-	Amine	145	55	155	30 + 120	100
Glob Top
Loctite ABLESTIK ME 995-1-4	Thermally conductive glob top	205,000	Silica	-	-	110	45	-	60	150
Loctite ECCOBOND EN 3838T	Low temperature cure PCB protection	6,700	-	-	-	2	57	217	8	130
Loctite ECCOBOND EO 1016	Encapsulation of smart cards and watch ICs	62,000	Alumina	N/A	Amine	126	46	140	20	150
Loctite ECCOBOND FP4323	COB and plastic PGA encapsulation	220,000 at 2 rpm	Silica (65%)	-	-	174	28	-	240 or 60	150 or 170
Loctite ECCOBOND FP4460	Automotive, BGA, memory, COB, SIP and SmartCard	300,000 at 10 rpm	Silica (75%)	120	Anhydride	173	20	70	180	150
Loctite ABLESTIK 8387BM	Discontinued - No longer available	14,000	PTFE, Silica	10	Hybrid Epoxy	122	88	168	5 or 60	150 or 100
Loctite ECCOBOND 50300HT	Wire bonded bare die encapsulation	130,000	Silica (68%)	150	Anhydride	140	20	-	60 + 60	120 + 150
Loctite ECCOBOND 50300-1	Wire bonded bare die encapsulation	100	Silica(70%)	-	-	140	20	-	120	150
Loctite ECCOBOND 50300LT	Wire bonded bare die encapsulation	55	Silica (69%)	-	-	140	20	-	120	150
Loctite ECCOBOND 50400-1	Wire bonded bare die on epoxy laminates	40,000 at 20 rpm	Silica(70%)	150	Amine	140	20	-	60 + 60	120 + 150
Loctite ECCOBOND FP4660	CSP and low stress applications	120,000 at 5 rpm	Silica (80%)	120	Anhydride	135	13	56	30 + 90	125+165
Loctite ECCOBOND UV8800M	Discontinued - No longer available	2,500 - 4,000 at 5 rpm	Silica (54%)	21	-	29	41	135	2 seconds	315 - 400 nm (UV)
Loctite ECCOBOND UV8800M-X	Discontinued - No longer available	3,400	-	-	-	47	48	149	30 sec	100 mW/cm2
Loctite ECCOBOND UV 9052	UV cure for inkjet applications	41,000	-	-	-	-	-	-	5 - 10 sec	0.5 - 1 J
Loctite ECCOBOND UV 9060F	Protection of WLCSP and BGA	11,000	-	-	-	75	81	198	5 - 25 sec	300 w/In
Loctite EO7021	CSP, BGA and SmartCard encapsulation	17,000 at 5 rpm	-	-	-	125	67	187	60 or 5	120 or 150
Loctite SI 5088	UV and moisture cure for gasketing and sealing on glass, metals and ceramics	65,000	Unfilled	-	Silicone	-	3	-	Mix	Mix
Loctite SI 5293	UV cure silicone for PCB protection	-	-	-	Silicone	-40	300	-	-	-
Loctite STYCAST 2851FT	Solvent free encapsulant	85,000	-	-	-	-	31	-	60	120
Loctite STYCAST SC3613	LED display coating and IC hybrid passivation	3,500	Unfilled	-	Silicone	-	-	-	30 + 60	120 + 150
Loctite STYCAST U2500	For transformer PCBs and insulation apps	6,000	Polyurethane	-	-	-53	155	-	240	60

Do you have UV cured silicons with high refractive index?

We don't have any high refractive index materials that cure with UV. The reason is because the UV activators needed to cure the material limit the transmission of the material. Furthermore, the UV exposure to the silicone damages the silicone itself, making it go yellow which further reduces the transmission.UV-cured silicones are usually not suitable for high transmission, high refractive applications.

What are PCB/Component protection encapsulants?

PCB protection encapsulants are used to protect passive components such as capacitors and resistors from dust, moisture and mechanical impact. LOCTITE ECCOBOND 3838T, a black color epoxy with low modulus to minimize stress on chip cap and UV9060F, a light blue UV acrylate with moisture cure that cures in shadowed areas are the first PCB protection encapsulants that come to mind.

Alternative, more or less colorless, options can be the tried and proven ABP 6892, the clear silicones 8035 and STYCAST SC 3613 and finally the UV/Heat Dual cure LOCTITE 3217. Quite a lot of options depending on your package.

It is also likely that you would need a DAM if you want the encapsulant to stay on the PCB. In this case we can recommend the black ABP 8420 epoxy or the black ABP 8142B silicone. Other potential candidates can be the more thixotropic LOCTITE 3621 red epoxy and LOCTITE 3217 that can be uv cured before the fill operation.

What causes bubbles in my Encapsulant?

You might be tempted to think that in the off chance you see bubbles in the encapsulant, the material is the one to blame. Sometimes this might be the case but most often than not it isn't. To be more precise, outgassing can be an issue in solvent based materials. The moisture from the solvent evaporates and bubbles are formed. BUT this cannot really be the case in most encapsulants such as FP4450 and FP4451TD that are 100% solid systems without any solvents. Outgassing levels are very, very low - which is also why they are used in aerospace and defence applications. In these cases the bubbles are coming from the SUBSTRATE rather than from the encapsulant.

Many laminate substrates are very moisture sensitive and absorb a lot of moisture over time (especially in uncontrolled humidity environments where the temperatures are warm). When you apply encapsulants such as FP4450 to these substrates, what you are seeing is not outgassing from the material, but rather, moisture escaping from the laminate and being trapped between the epoxy without being able to escape. But fret not. This can be avoided with prebaking.

What is substrate prebaking??

Prebaking is a preheating process that removes the moisture from substrates that have been previously exposed to humidity. Any laminate left exposed for a long period of time should be "prebaked" to remove moisture prior to application

Typical "prebaking cycles" are 100C for 1 hr or similar - it should be above 100C to let the moisture evaporate
Once the substrates are prebaked you can follow the recommended dispense and curing steps on the TDS
If you don't want to prebake, you can store the substrates in a "dry box" which is a nitrogen environment once arrived to keep moisture from absorbing
If you don't want to prebake or store in a dry box (you should and you should) then you CAN try to also do a lower temperature step-cure like 30mins @ 125C + 90mins @ 165C (advise the TDS depending on the specific material).

How do I know when my product is fully cured?

We expect that all the materials are fully cured after the recommended cure schedules in the TDS. You could perform DSC cure kinetics on the material, to ensure that the material is completely cured.

How many Volts can liquid encapsulants typically withstand?

Typical silica filled encapsulants will withstand 500 to 1000 volts/mil (20 to 40 kV/mm). So if, for example, 1400V is the operating voltage, the gap between electrodes should be around 3 mil or 75micron. Therefore, we need to verify the gap between the electrodes (not the thickness of the encapsulant) to make a judgement if the encapsulant can protect against this voltage .

Liquid resins are used in two main ways in encapsulations processes: glob top and dam & fill alternatively known as frame & fill

Epoxy Mold Compound vs Liquid Encapsulation

There are two main ways to encapsulate a semiconductor device: transfer molding a thermosetting Epoxy Mold Compound (EMC) or using liquid encapsulation directly on the Printed Circuit Board (PCB). Encapsulation in EMC is better than liquid encapsulation for applications that require higher filler content, and for the same reason, volume for volume, EMC is usually cheaper than liquid.

Liquid encapsulation, on the other hand, has a high flexibility and low through put

Liquid casting is however much more flexible. EMC requires are large significant investment in molding machines and mold plates for specific devices which must produce large quantities before there is a return on that investment. Liquid encapsulation on the other hand has a high flexibility and low through put: meaning that it is best suited for a multiple diverse low quantity orders.

In general liquid encapsulation is used for LEDs and potting or encapsulating electronics in bare die mounting on printed circuit boards (PCB), otherwise known as chip on board (COB).

Another advantage of potting and encapsulating devices in liquids is that in general, the result is flatter and thinner than devices encapsulated by a transfer molding process around a lead-frame with EMC. The space requirements for devices will continue getting more and more stringent as the component density of devices increases. This trend makes encapsulation and potting in liquids a sure bet for the future.

Transfer molding EMC may also cause wire sweep: where the pressure of the flowing molten compound shifts the fine-pitched bonding wires connecting a die. Wire sweep can cause shorts and mutual inductance. Liquid encapsulation is applied from above and does not disturb bonding wires. That’s why it is the industry standard for larger or extra sensitive dies and chips.

Liquid resin encapsulation via the glob top process is a single step application process but is less precise than dam & fill

Liquid Epoxy: Viscosity and Thixotropy

Bare die may be mounted to the PCB with die attach but that’s not enough to protect them or their connecting wires from moisture, mechanical stress, temperature, and chemical corrosion. That’s why it makes sense to insulate and encapsulate them with a protective potting layer of liquid encapsulant.

The low viscosity of liquid encapsulants is good for flat smooth finishes.

In non-Newtonian thixotropic encapsulants thixotropy refers to the temporarily lower viscosity of an epoxy gel when shear, pressure, or temperature is applied. This means that they can be gel-like when at rest, but flow like a liquid when agitated.

Being able to control the viscosity of liquid encapsulants means you can dial in how far they will spread over a surface area, and also how high they will build up to. This is important in Glob Top encapsulation where devices are literally encapsulated by a “Glob” from above.

Dam & Fill or Frame & Fill is a two step encapsulation process that is a little like 3d printing

Glob Top vs Dam & Fill

Glob Top is a process of encapsulation by using a fluid encapsulant gel with higher viscosity so that it fully encapsulates a device without flowing beyond the necessary area. As mentioned, by controlling the temperature, shear, and pressure, the viscosity and flow of liquid can be adjusted so that the final surface area and height of the “Glob” can be controlled quite effectively.

Dam & Fill on the other hand refers to a two-step process of encapsulation, where a ring or frame of higher viscosity liquid encapsulant is applied as a “Dam” around a device, and then a lower viscosity liquid “fill” is used to then fully encapsulate a device. The liquid used to build the frame or dam usually has more abrasive filler and a higher viscosity at rest than the liquid used for the fill.

Dam & Fill is a more selective protective coating and can be framed to cover areas in specific shapes, and is for example also used for optical bonding. In optical bonding the frame or dam is used to create a space between the glass and the display or touch screen. Then an optically clear fill is used as an adhesive and fixative.

Liquid Encapsulation for LEDs and Optoelectronic devices:

Optically clear liquid encapsulation is also used for LED devices, and encapsulate optical or optoelectronic devices that require both a high level of light transmittance as well as a good level of mechanical protection. In a similar process to Glob Top encapsulation, a literal glob of clear encapsulant is dropped directly into place on top of the LED. In another production process, optically clear liquid encapsulant is used to cast LED’s final body. Phosphor, colored dyes, and diffusant concentrates can be added to the liquid encapsulant to alter its optical properties.