Tag Archives: Adhesives

New – Battery Fabrication Product Brochure

10th March 2020

Inseto is pleased to announce the release of our new product brochure outlining the range of products used to produce cell, prismatic and advanced batteries, including battery interconnection equipment for ultrasonic bonding, torsional welding and mechanical testing of welds, plus related wire bonding consumable products.

In addition, we also provide Silicon, Glass and Fused Silica wafers and coating equipment for advanced battery technology, plus adhesives for bonding and sealing applications.

See Inseto at the forthcoming Battery Tech Expo at Silverstone Circuit on 26 March 2020 (date moved to 2 & 3 December 2020), where our experts will be available to answer your application specific questions and requirements.

Inseto Battery Fabrication Brochure

Please download a copy HERE

The Heat’s Off

13th December 2019

DELO MONOPOX TC2270, a new specialist adhesive ideal for chip bonding – and other applications where electrically insulated heat transfer is required – is now available from Inseto.

Andover, United Kingdom – Inseto, a leading technical distributor of equipment and materials, is now supplying DELO’s new MONOPOX TC2270, a thermally conductive, electrically insulating adhesive, which is ideal for bonding silicon die and other applications where rapid heat transfer is essential.

For example, heat build-up is a common reason for integrated circuit failure and the efficient dissipation of heat in power semiconductors, as used increasingly in automotive applications, is a considerable challenge. With a specific thermal conductivity of 1.7 W/mK, DELO MONOPOX TC2270 ensures efficient heat transfer between die and packaging. It is also cheaper than silver epoxy, which has the often-unwanted property of being electrically as well as thermally conductive.

Supplied in 10ml syringes, DELO MONOPOX TC2270 boasts many other benefits too. For instance, the minimum curing temperature is 60oC in about 90 minutes, which means it can be used with temperature sensitive materials with little risk of introducing stress or causing warpage. In addition, it is a one-part adhesive, so no mixing is required and storage is at -18oC, a temperature accommodated by standard commercially available freezers; whereas most die-attach adhesives need to be stored in industrial freezers at much lower temperatures, such as -40oC.

Once cured, DELO MONOPOX TC2270 delivers a die shear strength of 60N/mm2 and has an end-application use range of -40 to +150oC, which is more than adequate for most silicon-based semiconductors.

Eamonn Redmond, Sales Manager of Inseto, comments: “The adhesive’s chemistry includes aluminium nitride, which ensures heat is quickly transferred away from the die, thus increasing the potential lifetime of the chip. Also, the fact that it is readily available in 10ml syringes means that users reduce the risk of having to dispose of out-of-date adhesive.”

In addition to its good shear strength, DELO MONOPOX TC2270 boasts a relatively high flexibility (11% compared to the less than 2% exhibited by most epoxies), making it ideal for bonding larger die. It also has a very low water absorption figure of just 0.1% and, once cured, volume resistivity is greater than 1xE14 Ohm cm and its surface resistance is greater than 1xE13 Ohms.

DELO MONOPOX TC2270 has an anticipated shelf life of six months. The datasheet for this adhesive, along with others from the DELO MONOPOX one-part, heat-cured epoxies range, can be viewed online at Inseto’s website, which also contains the datasheets of other adhesive types (chemistries, curing methods etc.) and an extensive Knowledge Base library of articles and guidance notes.

Redmond concludes: “The TC2270 is an extremely useful adhesive in the world of microelectronics and in any application where heat must be transferred without establishing an electrical connection.” Inseto is DELO Industrial Adhesives’ exclusive distributor in the UK and Ireland. Other products available through Inseto include an extensive range of UV cured or light activated epoxies, light cured acrylates, light / heat cured epoxies, dual curing materials, light / anaerobic curing adhesives, 2-part polyurethanes, 1- & 2-part epoxies, cyanoacrylates and single part silicones.

For further information on these products please visit: https://www.inseto.co.uk/adhesives.php.

How to Choose the Right Adhesive (IKB-035)

Choosing an Adhesive: There are many factors that go into choosing the right adhesive for a particular application. This document offers guidelines on how to proceed with this sometimes tricky process.

Quite often, the last thing to be considered in a new project is the adhesive. After all, how difficult can it be to glue two things together? If it was really that simple, this document would not exist, and unemployment figures would increase (but probably not dramatically – there aren’t too many people who make a living from selling “glue” (legally, that is)).

The factors that influence the choice of an adhesive can be broken up into three categories:

Pre-Cure

Cure

Post-Cure

Some factors could fit into more than one category, equally there will be some debate as to which category a property belongs!

It is usually a matter of eliminating possibilities to see what is left – for example, to bond two very large items, a heat-cured adhesive will not usually be chosen. Think of the oven size required to bond the various components that make up the wing of an airplane.

Pre-Cure

In no particular order, here are some factors that should be considered at the pre-cure stage when choosing an adhesive:

Surfaces are bonded, not materials – an adhesive bonds to the surface! So is the surface plated? Does it oxidise easily, like copper?

Some materials should be avoided at all costs, e.g. PTFE (aka Teflon), most Polyethylenes (PE) – there is a reason adhesive bottles are made from PE!

If it is not possible to choose a material that is easy to bond to, then consideration must be given to pre-treatment. This can range from simple batch plasma cleaning to expensive in-line plasma ovens. Other possibilities include flaming, corona treatment, and sand-blasting.

Cleanliness – do the surfaces need to be cleaned? Always a vital consideration, and highly recommended by Inseto.

Storage of the adhesive a) at the customer’s facility, and b) in a cleanroom (not always needed) – recommended adhesive storage temperatures range from RT (∼23°) all the way down to -40°C. At the lower extreme, an industrial freezer is required, so lots of £’s need to be spent. Adhesives that need -18ºC storage can be stored in commercially available freezers, so all Purchasing Managers will be happier with this choice!

Adhesives that need to be stored below 0ºC require specialised transport, packed in large Styrofoam boxes containing ∼10Kgs of dry ice. There are only two courier companies willing to transport these, so transport costs can be very high.

Conditioning time – any adhesive stored in a fridge or freezer will need to be thawed to room temperature before it can be used. The technical data sheet will advise this conditioning time, but do not, under any circumstances, force the thawing, for example, by placing the adhesive container on a radiator! This will induce moisture into the adhesive, and cause a lot of problems both during and after cure.

Processing time, or pot life – this can vary widely from adhesive to adhesive. Generally Inseto offers adhesives with working a life of 48 hours to 12 months!

Mixing – if a two-part adhesive is chosen, the resin will need to be mixed homogeneously with the hardener. For small to medium volume applications, this can be achieved by purchasing the adhesive in a “twin-pack” – it looks a little bit like the barrels of a shotgun! For high volume applications, the adhesive will be supplied in large (10L / 20L) containers, and expensive, specialised mixing equipment is required to dispense from these.

Viscosity – too low, and the adhesive can’t be controlled; too high, and it won’t move after leaving the container. Horses for courses. Also, care needs to be taken when choosing an adhesive based solely on its viscosity. Look at the small print on the data sheet to see how the viscosity has been measured. Unless the test method is identical to another adhesive that might be under consideration, any comparison is invalid.

Flowing behaviour – this is not defined in any data sheet! It’s very difficult to quantity, but it can have a big effect on processing. Basically, what happens to the applied adhesive as the ambient temperature increases?

Application of the adhesive – manual or automatic? This is usually determined by the quantity to be assembled. For small volumes, a manual process is usually sufficient. For larger volumes, repeatability is key, so an automatic process is usually required.

The next factor is the method of application – dispense, jet, stamp, screen / stencil print, spray, brush? Each has its own advantages and disadvantages, and sometimes the nature of the adhesive will rule some in / out. For example, moisture sensitive adhesives should only be dispensed.

Finally in this section, it is important to consider how the waste, or unused adhesive, can be disposed. The easiest way is to somehow cure what is left in the container and then dispose of it in normal household waste – a cured adhesive is a plastic! But there will always be some unused adhesive that must be disposed, and engaging the services of a specialist disposal company can be expensive.

Cure

An adhesive is cured by one or more of the following methods: heat, light, moisture (sometimes mistakenly called air curing – it’s actually the moisture in the air that causes the adhesive to cure), mixing a resin and hardener, or, in the case of anaerobic adhesives, the absence of oxygen and the presence of metal.

Sometimes the cycle time dictates which adhesive is chosen. For example, the automotive industry and the mobile phone industry both require a large number of parts to be made in the shortest possible timeframe. So if one part needs to be assembled every 5 seconds, an adhesive that needs 30 minutes to cure will not be used – think of the size of the oven that would require!

Sometimes the materials being bonded dictate the adhesive. It is not possible (under normal circumstances) to bond two opaque parts together using a light-cured adhesive – how does the light get to the adhesive? When bonding to Polycarbonate, it is usually not possible to use a UV adhesive, as most grades of Polycarbonate block UV light (the trick in this instance is to use an adhesive that also contains a VISIBLE light photoinitiator). In addition, some plastics can’t withstand a high level of heat, so the adhesive needs to be cured at 60°C – 80°C maximum.

High intensity light is generally the fastest way to cure an adhesive. Cure times range from 1 second to 60 seconds, depending on the adhesive. The downside is material cost – due to the high cost of photoinitiators, this type of adhesive tends to be expensive. Having said that, the process cost, which is considerably more important than material cost as it is a true reflection of the cost of manufacture, is ALWAYS lower for light-cured adhesives, if the volumes are high enough.

The slowest curing mechanism is moisture. The cure rate for these adhesives is 2mm every 24 hours, so, depending on the geometry of the parts being bonded, the actual cure time can be days! Some, but not all, moisture cured adhesive can have their cure rate accelerated by adding heat, or increasing the moisture content in the ambient atmosphere

Between these two extremes lie heat-cured, cold-cured, and anaerobic-cured adhesives. Usually, anaerobic curing is the fastest of these, anywhere between 15 seconds and 5 minutes. Heat-cured adhesives will usually cure anywhere between 60°C and 180°C, while cold-cured adhesives cure at room temperature after mixing. The cure schedule for most cold-cured adhesives can be accelerated by using heat – as a general rule-of-thumb for epoxies, every 10°C rise in temperature reduces the cure time by half. The reverse is also true, so be careful when curing cold-cured adhesives in the wintertime when some ambient temperatures can drop below 20°C.

When using a heat-cured adhesive, remember to include the heating-up time for the assembly. If a technical data sheet states that an adhesive cures at 120°C for 30 minutes, curing only starts when the adhesive reaches 120°C. This is especially critical when bonding metal, as it can act as a heat sink and remove heat from the adhesive.

One final point concerning the curing of heat-cured adhesives: Be very careful of curing at the bottom edge of the process window. For example, if a data sheet gives a minimum cure temperature of 80°C, it is usually for a good reason – below this, the adhesive just will not cure, no matter how long it remains in the oven. If the oven is set to 80°C, it is almost 100% guaranteed that not all areas within the oven are actually at this temperature. So if the parts to be bonded are placed in one of these areas, the adhesive will never cure. It is better to set the oven to cure at 82°C -84°C to ensure that the adhesive cures.

Post Cure

There is potentially a very long list of “things” that the cured adhesive must provide. It is worth noting that despite the technical values that appear on a data sheet, these usually apply only to the adhesive, and the adhesive will behave very differently when it is bonding two parts together. The complete assembly must be tested by the customer to ensure reliability. After all, one customer’s aluminium might be a very different (grade of) aluminium than another customer is using.

Here are some of these “things”, again in no particular order!

Bond strength – this is usually one of the first factors considered when choosing an adhesive! How strong must the join be? Most customers will reply “as strong as possible”. There are two elements to “bond strength”: cohesive bond strength, and adhesive bond strength.

Adhesive bond strength is defined as the bond strength of the adhesive to the materials being bonded. In every case, this has to be tested in the specific application under discussion. No two materials give the same bond strength, so an adhesive that bonds well to stainless steel might be terrible with aluminium. Even within a generic material such as Polycarbonate, care needs to be taken. There are in excess of 100 grades of Polycarbonate available, and each will probably bond differently! Generally, the technical data sheet will point in the right direction, so it’s a very good starting point, but only a starting point.

Cohesive bond strength is more straightforward, it is the inherent strength of the adhesive, and is independent of the materials that it is bonding. It will be specified on the data sheet, and is measured simply by curing a test coupon of the adhesive and then pulling it apart until it breaks! The force required to break it is the strength of the adhesive, called the tensile shear strength (sometime just the tensile strength).

Flexibility – there are different ways to indicate the flexibility of an adhesive: elongation, Young’s Modulus, sometimes shore hardness. Elongation is the easiest to both measure and visualise – it is calculated in the same test that determines the tensile strength of the adhesive. The percentage that the test coupon has strength when it breaks is the elongation, also specified in the data sheet – simple!

Temperature resistance – this will usually be specified on a data sheet, and depending on the application, will be more or less important to each customer. For those working in the military, aerospace and automotive fields, the temperature range of interest will be from -40°C or -55°C to +125ºC or +150ºC. For commercial applications, it will be much narrower, usually from -20°C to +80°C.

For tests such as temperature cycling and thermal shock, no data sheet will state “our adhesives survive” these tests. The temperature rating specified on the data sheet is a very good guideline (for example, an adhesive that is only rated to 80°C should not be considered for an application that must work up to 120°C.), but it not an absolute guarantee. Again, the complete assembly must be tested to ensure these requirements are met.

Chemical resistance – there are so many different chemicals that could possibly come in contact with the bonded assembly that it is absolutely impossible to test for all of them. Most application areas will have their own set of chemicals that the adhesive must survive. For example, in the automotive industry, this set usually consists of petrol, diesel, AdBlue, engine oil, brake fluid acetone, and maybe DI water. However, the mobile phone industry will have a completely different set of fluids, coffee, alcohol and water being the most frequent!

As a general guideline when choosing an adhesive for an application that needs a high chemical resistance, keep away from flexible adhesives. These tend to have a less rigid molecular chain once cured, so it is easier for chemicals to penetrate the adhesive and attack the bond. Hard, rigid adhesives generally offer the best chemical resistance.

Applications that will see changes in temperature over their lifetime need to consider how the adhesive expands and contracts with these temperature changes. Two very important characteristics of the adhesive need to be consider here – the glass transition temperature (Tg) of the adhesive, and the coefficient of thermal expansion (CTE) of the adhesive. These are directly related to each other.

The Tg is defined as the temperature at which the mechanical and physical properties of the adhesive start to change. Below the Tg, the adhesive network is in a solidified, relatively immobile condition. Above the Tg, the polymer chains of the adhesive may move slightly relative to each other, independent of the degree of cross-linking (i.e. curing). This may cause the adhesive to “soften” slightly above the Tg, but the degree of softening varies according to the adhesive.

In an ideal world, the chosen adhesive should have a Tg in excess of the operating temperature of the end application. As the Tg is exceeded, the adhesive softens, even if it is only very slightly. As the operating temperature comes back down below the Tg, the adhesive will harden slightly. Doing this thousands of times during the lifetime of the application will induce stress into the adhesive, causing the join to fail more quickly than it should.

CTE is defined as how the size of an object changes with changes in temperature, and is usually expressed in parts per million (ppm). Technical data sheets should contain two CTE values – ∝1 for the CTE below the Tg, and ∝2 for the CTE above the Tg. They will nearly always be significantly different values!

When bonding similar materials together, e.g. glass to glass, CTE is not an issue as both materials will expand and contract at the same rate. However, when bonding dissimilar materials such as glass and aluminium, the trick is to choose an adhesive with a CTE that is somewhere in between the CTE’s of the glass and the aluminium – around 4ppm for glass and 23ppm for aluminium. While it may not sound much, this can be a huge difference for large pieces.

Summary

As evidenced above, there are A LOT of things to take into account when choosing an adhesive! Like most things in life, there will be a compromise between some of these. It’s usually a good idea to create a list of “must have” properties, and “nice to have” properties – it can add clarity to the choosing process. Good luck!

For more detailed information on any of these topics, e-mail enquiries@inseto.co.uk

For further information on our full adhesives, please click HERE

Author

Date

Version

Author

Eamonn Redmond

Date

15 June 2017

Version

IKB035 Rev. 1

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Dual Cured Adhesives (IKB-012)

Dual cured adhesives: As joining and sealing applications become more and more complex, the demand for adhesives with multiple curing mechanisms is significantly increasing. This article provides an overview of the different dual curing adhesives manufactured by Delo, their hybrid chemistries, curing methods and typical applications.

Delo has developed an extensive portfolio of dual cured adhesives based on dissimilar chemistries, which offer significant advantages over more “traditional” adhesives, without sacrificing reliability, bond strength, or ease-of-use. Uses include industrial displays, automotive camera modules, electric motors, and even simple applications such as thread-locking.

When bonding components together, it is essential that the whole volume of the adhesive is fully cured, as uncured adhesive in the finished assembly may cause corrosion, or, in the case of optical products, interfere with the light path. For light cured adhesives (Ultra Violet & Visible Light), achieving full cure can be a problem due to shadow areas that the light can’t reach. Heat-cured adhesives do not suffer from this problem, but some components can be sensitive to temperatures even as low as 90-100°C. Two-part cold-cured adhesives such as epoxies and polyurethanes can overcome this issue, but the user then must suffer from the long curing times that these adhesives require, thereby increasing cycle times and reducing throughput.

Dual Curing Adhesives

Diverse Curing Mechanisms – What’s Available?

Dual-cured adhesives overcome these issues in different ways, depending on the chemistry of the adhesive. Currently, hybrid light + heat cured adhesives appear to be the preferred solution, but other chemistries such as light + humidity and light + anaerobic adhesives are gaining in popularity.

Diverse Curing Mechanisms for dual curing adhesives.

Light + Heat Cured Adhesives

These are based on two diverse chemistries, epoxy and acrylate. Epoxies tend to be hard once cured, offering increased resistance to chemical and temperature stresses due to the tight cross-linking of the polymer that occurs during cure. Acrylates are usually softer adhesives, enabling quicker curing and greater flexibility of the cured adhesive.

Using a combination of heat and light to cure these adhesives offers the user a very fast fixation by snap-curing the photoinitiator in the adhesive. Subsequent heat curing ensures that there is no uncured adhesive in any shadow zones that might exist in the assembly. This fast fixation also allows increased accuracy for the user – this is especially useful for companies that have invested heavily in high-accuracy placement machines, only to see that investment wasted due to movement of the parts being bonded during the heat-cure stage.

This heat-cured stage generally involves heating the parts up to around 100°C after the light cure process. However, for temperature-sensitive materials such as some plastics, modified epoxy adhesives are available that will cure at 60°C, combining defined processes and short cycle times, despite the low curing temperature of the adhesive. These are especially useful in applications such as automotive camera modules, or where the end product is subjected to chemical influences that would otherwise harm an acrylate adhesive. These dual-cured epoxies also exhibit very low outgassing (some are NASA-qualified) and low yellowing, making them ideal for applications with demanding optical requirements, such as LED assembly.

Dual-cured acrylates offer similar advantages to dual-cured epoxies, namely very fast fixing and full cure after subsequent heat curing, but these adhesives also exhibit excellent impact resistance and tension-equalising properties due to their flexible nature. These are ideally suitable for applications such as the assembly of rotary encoders, where optional fluorescing and colouring can be added to aid visual inspection.

Light + heat cured adhesives also offer increased flexibility in the manufacturing process. While heat-curing is mandatory for a small number of these adhesives, the majority offer independent curing mechanisms, allowing curing either by light, or by heat, or by a combination of the two.

Dual curing adhesives using light and heat curing mechanisms.

Light + Humidity Cured Adhesives

Light + humidity cured adhesives also enable a fast fixation by light, but the secondary curing mechanism in this instance is humidity, so there is no requirement for additional curing equipment. The majority of the assembly should be capable of being cured by light, to achieve optimum bond strength, but for applications such as mobile phone displays, where only the black border prevents light getting to the adhesive, then humidity curing at a rate of 2mm / day is the ideal secondary curing mechanism, enabling immediate handling after the initial light-cure process.

These are also single-part adhesives, and are free of isocyanates (no Health & Safety issues) and silicones (no impediment to subsequent adhesive bonding), unlike some acrylates. They are highly flexible, optically clear adhesives offering excellent climatic resistance, whilst also providing excellent bond strength on surfaces such as glass, PMMA, metal pins and most plastics.

Adhesive light curing equipment

Anaerobics

These are one-part adhesives that afford a relatively high temperature resistance (up to about 200°C) and tensile strength of about 15MPa. They cure in the absence of oxygen and the presence of a metal (though not all metals) and are frequently used for magnet bonding and thread-locking. Curing is at room temperature and, thanks to recent developments within the adhesives industry, any exposed adhesive (i.e. in contact with air) can be cured using UV light. Storage is at room temperature.

Dual curing adhesives using light and anaerobic curing methods to cure.

Conclusions

Dual-cured adhesives provide increased flexibility in the manufacturing process, giving end users more freedom when designing the manufacturing flow. They eliminate the unwanted possibility of uncured adhesive in the end product, and offer maximum placement accuracy when building complex assemblies on expensive equipment.

For further information on our full range of dual cured adhesives, please click HERE

Author

Date

Version

Author

Eamonn Redmond

Date

11 November 2016

Version

IKB012 Rev. 1

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Adhesives for PCBs (IKB-040)

We take a look at some of the ways adhesives are used for PCB and electronic assembly applications. (IKB-040)

PCB Adhesive: Component Fixing

Component fixing pre-reflow in PCB assembly. It is often necessary to tack small SMDs, such as resistors and capacitors, into place to prevent their movement during reflow, as even a minute drift away from the solder paste pads will compromise quality. The best type of adhesive to use here is a heat-cured, one-part epoxy. These offer high thermal resistance, as they need to withstand three reflow passes (the industry norm) at circa 220°C.

Placement of the adhesive is typically by automated dispenser before the board goes into the pick-and-place machine. A consideration here though is the time between the two activities. If it is likely to be a long time, you may need to assess the epoxy’s sensitivity to moisture.

Regarding storage, the latest one-part epoxies to join the market require a temperature of less than 10°C and some can be as low as -40°C. Curing temperatures vary from 60 to 150°C and curing time will typically be less than an hour.

PCB Adhesive: Socket Securing and Pin Coating/Sealing

This is done mainly to prevent moisture ingress and to reduce the risk of dendritic growth. There are two options available for securing/bonding pins/sockets. The first is to use a light-cured epoxy (see photo). These are popular as they cure very quickly in the presence of a high intensity light-source, making them ideal for high volume, rapid-turnaround production runs.The second option is to use a dual-curing (but again one-part) epoxy. High intensity light can be used for a rapid, initial cure, so that the board can be handled. This is then followed by heat curing – some of which can be time spent in the solder reflow oven – and will cure any epoxy ‘shadow zones’ (i.e. areas the light could not penetrate).

Adhesives for sealing and securing electronic components.

PCB Adhesive: Coil Fixing

The objective here is primarily to provide additional strength (see photo). Choke coils have a relatively higher mass than most electronic components, and bonding can protect against the effects of shock and vibration.

A two-part epoxy would be best to use, applied manually before soldering. There are no major curing issues, as the soldered joints will hold the coil in place while the adhesive cures (which is typically viscous and won’t run) at room temperature. Storage pre-use is typically at room temperature too.

Silicone encapsulation of PCB's. using high purity electronic grade silicone's.

PCB Adhesive: Ferrite Bonding

Here, the bond might be ferrite-to-PCB or ferrite-to-ferrite (e.g. the two halves of a transformer integral to the board). Because at least one surface is metal, the best adhesive to use would be a one-part anaerobic, a common use for which is thread-locking. Curing is at room temperature in the absence of oxygen, so any visible adhesive (i.e. at the edge of the bond) will remain viscous/liquid and should be removed. However, recent anaerobic adhesives to join the market can also be UV cured, meaning the excess adhesive can be treated.

PCB Adhesive: Casting / Potting

This is typically for circuitry intended for use in harsh environments; to protect the PCB from moisture and contamination (see photo). The adhesive-of-choice would be a two-part epoxy, as they are relatively low cost and a significant volume might be required for some applications. Pre-use storage and curing (which takes about 24 hours) is at room temperature.

Potting of PCB's using epoxies for harsh environments.

For further information on other example electronic applications for our adhesives, please click HERE.

Author

Date

Version

Author

Eamonn Redmond

Date

01 October 2018

Version

IKB040 Rev. 1

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Encapsulation Adhesives

Encapsulation Adhesives Key Features

  • High purity adhesives for bare die encapsulation
  • Glob-top and daml & fill materials
  • Low CTE to prevent substrate warpage and breaking of wirebonds
  • High Tg to minimise stresses, both during and after cure
  • Excellent protection against mechanical stresses (temperature, vibration, etc.)
  • Very high chemical resistance, e.g. automotive fluids, printing inks, etc.
  • Option of heat-cured or UV-cured product ranges

Protecting bare silicon die is done in a variety of ways, by over-moulding in traditional semiconductor packaging, in metal hermetic packages, or by glob top adhesive encapsulation on organic substrates.

Depending on the die size, either a single-stage glob top is used or, for larger die, a two-stage process of damming the die with a high-viscosity adhesive and filling the enclosed space with a low-viscosity compatible adhesive.

For useful information on choosing the right glob top adhesive for encapsulation, or help in understanding the terminology, and processing and technical guidelines, please look at our Knowledge Base Fact Sheet here.

DELO’s family of heat-cured anhydride-curing epoxies offer significant advantages to the user:

  • Dam heights of 3mm and above
  • Simultaneous curing of Dam and Fill
  • Fast curing times of 20 minutes at 150°C
  • Optional low-temperature cure temperature at 100°C
  • Operating temperature range from -65°C to +180°C
  • Low CTE’s of < 25ppm for thermal mis-match compensation
  • High Tg’s of approx. 180°C, with decomposition temperatures in excess of 320°C
  • Excellent chemical and media resistance
  • Compliance with JEDEC MSL 1 requirements
  • Thermal shock resistance of > 1,000 cycles from -40°C to +150°C
  • High purity with < 10ppm ionic impurities
  • Low humidity sensitivity with < 0.1% water absorption

In addition, DELO offers UV-cured epoxies for:

  • Very fast curing (seconds)
  • Short cycle times = high volume assembly
  • Simultaneous curing of Dam & Fill
  • Operating temperature range from -40°C to +150°C
  • Excellent chemical and media resistance
  • High purity with < 10ppm of Na+, K+, Cl ions

Example Applications

Encapsulation & GlobTop Adhesive Product Range

Related Products

Knowledge Base Articles

Further Information

Contact Us

Tel: +44 (0)1264 334505

Email: enquiries@inseto.co.uk

Applications

Bonding, Glob-Top, Encapsulation, Z-Axis Bonding, Sealing, Potting, Protection Against Vibration, Conductive Electrical Connection, Dam & Fill

Industry Segments

Microelectronic / Hybrid Assembly, Semiconductor Assembly / Back-end Assembly etc., Fibre Optics, Photonic Assembly, Microwave Electronics, OEM Equipment Manufacturers, Precision Components & Assemblies, PCB Assembly, Electronic Component / Device Assembly, Smart Cards, Smart Labels, RFID, Automotive Electronics etc.

Region

Available from Inseto in the United Kingdom & Ireland

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