TWI784922B - Led lamp, method of making led lamp, and method for encapsulating led device - Google Patents

Abstract

An LED lamp, a method of making an LED lamp and a method for encapsulating an LED device are provided. The LED lamp is formed from a die substrate wherein the substrate has formed thereon a semiconductor material, an electrode for the application of a bias across the semiconductor material for causing light to be emitted therefrom, and an adhesive that bonds the die substrate to a support substrate, wherein the adhesive is a polymerized siloxane polymer having a thermal conductivity of greater than 0.1 watts per meter kelvin (W/(m．K)) wherein the adhesive is not light absorbing, wherein the siloxane polymer has silicon and oxygen in the polymer backbone, as well as aryl or alky groups bound thereto, and wherein the adhesive further comprises particles having an average particle size of less than 100 microns.

Description

LED lamp, manufacturing method of LED lamp and secret of LED device sealing method

This invention relates to LED lamps. In particular, the invention relates to an LED lamp comprising a die substrate formed on a semiconductor material; electrodes for applying a bias voltage across the semiconductor material to cause light to be emitted therefrom; and bonding the die substrate to a support substrate Adhesives. The present invention also relates to a method for manufacturing an LED lamp and a method for sealing an LED device.

Light emitting diode (LED) lighting systems are becoming more widely used in place of traditional lighting. Light-emitting diode lamps (an example of solid-state lighting) can be tuned to the precise color desired due to lower energy usage, increased stability, and longer lifetime, ability to be used in a wider variety of applications than fluorescent lighting advantages over traditional lighting such as incandescent light bulbs, halogen lighting, or fluorescent lighting. In some embodiments, a single LED die/die is within the lamp, and in other embodiments, multiple LEDs are within the same lamp. The housing of the LED lamp can be manufactured to the same specifications as the incandescent bulb, thus allowing it to be used where the incandescent bulb is used.

Light-emitting diodes (LEDs) are solid-state devices that convert electrical energy into light, and a Generally have at least one semiconductor material with n-doped and p-doped parts. Organic light-emitting diodes are also known. When a bias voltage is applied across the semiconductor material, holes and electrons are ejected into the active layer where they recombine to generate light. Light is emitted from the active layer and can be directed primarily in one direction, or in any direction, depending on the type of LED.

LEDs can provide white light by a single LED, such as by a blue or violet LED, with a phosphor that shifts the light closer to perceived white light. LEDs may be provided in a single color, such as red, green or blue, or may be provided as different colored LEDs in the same lamp combined to provide white light. Examples of LEDs may include red LEDs using GaAsP and green LEDs using GaP, and nitride semiconductor LEDs forming green, blue, or ultraviolet light. As LEDs become brighter, heat dissipation becomes an increasing concern because heat buildup can degrade LED performance.

LED lamps comprising crosslinkable polymer compositions are disclosed in US 2009221783, US2012123054, WO20100267, US 2011171447 and JP 2004225005.

It is known that polymer compositions are insufficient in properties such as thermal stability.

One object of the present invention is to provide LED lamps.

Another object of the present invention is to provide a method for manufacturing an LED lamp.

The third object of the present invention is to provide a sealing method for LED devices.

The invention is based on forming an LED lamp formed from a die substrate on which a semiconductor material is formed; electrodes for applying a bias voltage across the semiconductor material to cause light to be emitted therefrom; and bonding the die substrate to the supporting substrate Adhesive.

In the present invention, the adhesive has a thermal conductivity greater than 0.1 W/m. Kerven (W/(m.K)) polymerized siloxane polymer, wherein the adhesive does not absorb light, wherein the siloxane polymer has silicon and oxygen in the polymer main chain, and aryl groups bonded to it or an alkyl group, and wherein the adhesive further includes particles with an average particle size of less than 100 microns.

According to the present invention, the manufacturing method of an LED lamp includes the following steps: forming a light-emitting diode by providing a semiconductor material and doping the semiconductor material on a first substrate; providing a supporting substrate; and providing an adhesive formed of a siloxane polymer. An adhesive composition, the adhesive composition further includes particles with an average particle size of less than 100 microns and a catalyst. A bonding agent composition is deposited to bond the first substrate to the supporting substrate. By applying temperature and/or light, the crosslinking groups of the siloxane polymer are activated to further polymerize the siloxane polymer and harden the polymer while bonding the die substrate and the packaging substrate together.

In a method of encapsulating an LED device comprising light emitting diodes, a semiconductor material is provided on a first substrate and it is doped. Provided is a composition comprising a sealant, the sealant composition comprising a siloxane polymer having silicon and oxygen in the polymer backbone, and an aryl group or an alkyl group bonded thereto, and Combined functional crosslinking groups, the adhesive composition further includes particles and catalysts with an average particle size of less than 10 microns. An encapsulant composition is deposited to encapsulate the light emitting diodes, and temperature and/or light are applied to activate the crosslinking groups of the silicone polymer to further polymerize the silicone polymer and harden the polymer.

The above-mentioned polymerized and hardened silicone polymers generally have at least 96% mass after polymerization compared to before polymerization. Typically, silicone polymers do not absorb greater than 25% of the visible light incident thereon.

gain a considerable advantage. Therefore, the thermal conductivity of the adhesive is high, and the adhesive is thermally stable. An excellent shelf life is also achieved, in particular storage prior to use. Typically, there is minimal increase in viscosity (cross-linking) during storage, and storage, shipping, and subsequent application by the customer can all be carried out in the absence of solvents, avoiding solvent capture in layers subsequently formed in the final product , shrinkage during polymerization and mass loss over time during device use.

Example embodiments will be more clearly understood from the following description taken in conjunction with the accompanying drawings.

10, 10a, 10b: electrodes

12: n-doped gallium nitride region

13: p-doped gallium nitride region

14: Sapphire substrate

16, 40, 42, 44: substrate

17: Adhesive layer

19, 20, 30: Package substrate

22: Die Attach Adhesive

24, 51: grain

25, 45: line bonding

28: Phosphorescent layer

29: Sealant layer

35: Phosphorescent material

37:Second sealing layer

41: Semiconductor materials

43: Adhesive

46: Silicone particle adhesive

47, 48: Electrical connection area

49: Silicone material

50: Package substrate

52: Covering the substrate

53: Silicone sealant

55: Conformal layer

FIG. 1 illustrates an example of a light-emitting diode formed on a light-transmissive substrate.

FIG. 2 illustrates an example of a light emitting diode formed on a light reflective substrate.

Figure 3 is an illustration of an LED with a front transparent encapsulant.

4 is an illustration of an LED within a cavity of a package with encapsulant within the cavity.

Figure 5 illustrates LED flip-chip packaging.

Figure 6 shows a plot of refractive index versus wavelength for different particle loadings.

Figure 7 is a graph of transmittance versus particle loading.

Figure 8 illustrates the mass change of siloxane polymer during thermally induced polymerization.

Figure 9 illustrates the thermal stability of silicone materials after deposition and polymerization.

Figures 10a-10d illustrate additional examples of LED encapsulation.

Various example embodiments will be described more fully hereinafter with reference to the accompanying drawings in which some example embodiments are shown. Inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this description will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to as being "on," "connected to," or "coupled to" another element or layer, the element or layer can be directly on the other element or layer. A layer is on, directly connected to, or coupled to another element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. Floor. Like numbers refer to like elements throughout. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It should also be understood that although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, such elements, components, regions, layers and/or sections Should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the inventive concept.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. should enter It is to be further understood that the term "comprises" or "comprises" when used in this specification specifies the presence of stated features, regions, integers, steps, operations, elements and/or components, but does not exclude one or more other features, regions , integers, steps, operations, elements, components and/or the presence or addition of groups thereof.

Additionally, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another as illustrated in the drawings. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the drawings. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. Thus, the exemplary term "lower" may thus encompass an orientation of "lower" as well as "upper" depending on the particular orientation of the drawings. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "under" can encompass both an orientation of above and below.

It should be noted that, as used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It should also be understood that when the terms "comprises" and/or "comprising" are used in this specification, it specifies the presence of stated features, steps, operations, elements and/or components, but does not exclude the addition of one or more other features, Steps, operations, component assemblies and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should be further understood that terms (such as those defined in commonly used dictionaries) should be interpreted to have meanings consistent with their meanings in the relevant art and in the context of the present invention, and will not be interpreted ideally unless expressly so defined herein. over-form interpret the meaning.

The lowercase letters used in the formulas of the following monomers and polymers especially denote integers.

Silicone particle materials as disclosed herein can be used in any desired LED device, however, as a first example, a GaN LED can be used. GaN-based LEDs are a specific type of light emitting device known as solid-state light sources, which have many advantages such as compactness, low power consumption, long lifetime, contain no mercury, have high efficiency, and have low service rates. GaN LEDs are available in different forms and combinations for lighting applications, such as a) a combination of three types of monochromatic LEDs (blue, green, red); b) a combination of blue LEDs and yellow phosphor powder; c) UV LEDs Combination with three-color red-green-blue fluorescent powder, and other combinations and implementations.

Based on complementary color theory, white light can be obtained using blue LEDs through the combination of YAG:Ce fluorescent materials with yttrium-aluminum-garnet structure. Since the light emitted from YAG is yellow-green, the resulting white light is characterized by a high color temperature and a cool tint such that the color scale is not satisfactory for all uses. Therefore, green, yellow or red phosphor powders can be added to obtain white light with different color temperatures (cool to warm) and improved color rendering. Other phosphorescent hosts, in particular those based on silicates, sulfates, nitrosilicates and pendoxo-nitrosilicates, can be used to improve color rendering.

More specifically, white LEDs can use 450nm-470nm blue gallium nitride (GaN) LEDs covered by a yellowish phosphor/scintillator coating, which can be made of YAG:Ce treated with cerium. Made of yttrium aluminum garnet crystals. Since yellow light stimulates the red and green cones of the human eye, the resulting mixture of blue light emitted from the GaN LED and yellow light emitted from the phosphor appears as white light. Other combinations of LEDs and phosphors can also produce the appearance of white light. Combinations of LEDs can give the appearance of white light, such as Homoepitaxially grown ZnSe on a ZnSe substrate whose active region emits blue light and emits yellow light from the substrate. Additionally, combinations of red, green, and blue LEDs are known to produce white light with or without phosphors. Also possible are tungstate, carbonitride, molybdate and selenide phosphors, and quantum dots.

The combination of YAG phosphor and blue LED is a common combination for situations where high color rendering index (CRI) and warm color temperature are not required. Alternatively, silicate phosphors are possible, eg silicate phosphors that emit green, yellow and orange (such as 507nm to 600nm) from UV violet and blue light sources. For LED applications that require warm and saturated red colors, such as displays or residential/retail lighting, red and/or green phosphors may be required. Nitride phosphors (or oxynitride phosphors) are possible. Red nitride phosphors can emit colors such as between 620 nm and 670 nm. Also possible are, for example, aluminate phosphors emitting light in the green or yellow spectrum, such as 516 nm to 560 nm.

As can be seen in Figure 1, on a sapphire substrate 14, n-doped gallium nitride regions 12 are shown. An n-type semiconductor region can be created by doping GaN, for example, with silicon or oxygen. A p-doped gallium nitride region 13 is also illustrated. A p-type semiconductor region can be produced by, for example, doping GaN with magnesium. Electrodes 10a and 10b are illustrated and are used to provide a bias voltage across the GaN semiconductor region to cause the LED to emit light, in this example light is emitted in all directions.

Instead of sapphire substrates, it is possible to use SiC substrates (on which InGaN semiconductors are formed), such as Cree, Inc. LEDs. Alternatively, a GaN substrate with a doped GaN semiconductor region on it is also possible, such as LEDs from Soraa, Inc., or a Si substrate with a GaN semiconductor on it, such as Bridgelux Inc. , Inc.) or OSRAM (Osram, Inc.) LED. The use of silicon substrates has the advantage of using large wafer sizes (such as 6-inch wafers, 8-inch wafers or larger) benefits.

As can be seen in FIG. 2 , a substrate 16 of SiC or Cu is provided, with regions 13 of p-doped GaN and regions 12 of n-doped GaN thereon. Electrode 10 is also illustrated. A bias voltage applied between the substrate 16 and the electrodes 10 causes the LED to emit light. As can be seen in Figure 2, the light is mainly directed in an upward direction. In the example of FIG. 2, p-doped regions are provided closest to the die substrate, while in the example of FIG. 1, n-doped regions are provided closest to the die substrate.

As illustrated in FIGS. 1 and 2 , a die attach adhesive layer 17 is provided to attach the substrate (sapphire, SiC, Cu, GaN, Si, etc.) to a support or packaging substrate 19 . LED die attach adhesive is preferably but not necessarily thermally conductive (eg, may have greater than 0.5 watts per meter. Kelvin (W/(m.K) in case of optical reflection), preferably greater than 4.0 watts /m.Kervin and preferably greater than 10.0 W/m.Kervin thermal conductivity. Depending on the material and concentration chosen, much higher thermal conductivity (such as greater than 25.0 W/m.G Erwin or greater than 50.0 W/m. Kelvin) is also possible. However, if the adhesive or sealant is transparent, the thermal conductivity is usually greater than 0.1 W/m. Kelvin (eg 0.1 W /m.Kelvin to 0.5W/m.Kelvin, or such as greater than 0.2W/m.Kelvin, such as greater than 0.5W/m.Kelvin). Whether as an adhesive or a seal As an agent, the silicone material can be deposited as a fluid, such as a liquid or a gel, such as dispensed by methods such as syringe deposition or screen printing. Other deposition methods can be used, such as spin coating, dipping, inkjet, curtain coating Cloth, Drip, Roller, Gravure, Reverse Offset, Extrusion Coating, Slot Coating, Spray Coating, Flexo, etc.

The LED die attach adhesive can be electrically insulating or conductive. In the example of Figure 2, since the die substrate is one of the electrodes, the LED die attach adhesive should also be conductive, such as having a value less than 1×10 ^-3 Ω. The resistivity of m is preferably less than 1×10 ^-5 Ω. m, or even less than 1×10 ^-7 Ω. The resistivity of m. In the example of FIG. 1, the LED die attach adhesive can be electrically insulating or conductive. If conductive, the resistivity may be within the range as described above with respect to FIG. 2 . If it is electrically insulated, the resistivity can be greater than 1×10 ³ ohms. Meters, such as greater than 1 × 10 ⁵ Euro. Meters, or even greater than 1×10 ⁹ Euro. meter.

The LED die attach material is preferably not optically absorptive in the visible spectrum (or, for example, in the spectrum in which the LED emits light, such as ultraviolet light). The die attach layer is transmissive to visible (or UV) light, wherein at least 80%, preferably at least 85%, and more preferably 90% of the visible light normally incident thereon is transmitted. It is also possible to transmit 92.5%, or even 95% or more of visible light. If a transparent die attach material is used, a reflective layer on the support substrate or packaging substrate may be provided to reflect light if necessary to improve the brightness of the light output from the LED lamp.

In an alternative example, the LED die attach material is highly reflective. The die attach material is reflective to help redirect light towards the package substrate or support substrate to be directed out of the package, thus improving the brightness of the LED lamp. Preferably, in this example, 85% or more of light is reflected by the LED die attach layer, or 90% or more, or even 95% or more of visible light. Die attach material can be placed not only under the die, but also around the sides of the die to reflect light emanating from the sides of the device.

Silicone particle materials as disclosed herein can also be provided on the front side of the LED as a barrier layer or encapsulant. As can be seen in FIG. 3 , die 24 is attached to package substrate 20 via die attach adhesive 22 . In this example, the die attach adhesive may be as described above, or may be a conventional die attach adhesive such as those made from metal solder, glass frit, polymer epoxy, etc. . Die 24 is a simplified illustration of an LED device with a layer of semiconductor material on the die substrate, and wire bonds 25 electrically connect the die to the packaging substrate. If necessary, a phosphor layer 28 is also provided to shift the wavelength of the light emitted by the LED from a first wavelength of light to a second wavelength of light. Preferably, the first light The two wavelengths are within the visible spectrum, however, the first wavelength of light may be within the visible spectrum, or outside the visible spectrum, such as UV light.

It is also possible that no phosphor is present, so that no phosphor layer 28 is provided. If a phosphorescent layer 28 is provided, then according to this example, the phosphor is provided within a silicone material as disclosed herein, optionally including particles, but preferably not. An encapsulant layer 29 is provided with or without phosphor layer 28 to surround and protect the LED device on the packaging substrate. If the phosphor layer 28 is not provided, or is provided without phosphor, it is possible to provide a phosphor material within the encapsulant layer 29 if necessary. Both the phosphorescent layer 28 and the sealant layer 29 may be equipped with a phosphorescent material as necessary. Encapsulant layer 29 may be made from a silicone material as disclosed herein, with or without particles added thereto.

An alternative example is shown in Figure 4, which illustrates a packaging substrate 30 having a die 32 bonded thereto via a bonding layer. As mentioned with respect to FIG. 3, the bonding layer can be a silicone particle composition as disclosed herein, or another type of die attach material. Die 32 is a simplified view of an LED device, preferably having p-doped regions and n-doped regions, semiconductor material such as doped GaN disposed on a substrate such as sapphire, SiC, Cu, Si, GaN, and the like. If necessary, a first sealing layer with phosphorescent material 35 is provided and/or a second sealing layer 37 is provided. The phosphorescent material 35 and the second sealing layer 37 may be as described above with respect to layers 28 and 29 of FIG. 3 .

Illustrated in FIG. 5 is a flip chip package for an LED device in which a semiconductor material 41 (eg GaN) is provided on a transparent substrate 40 (eg sapphire). In a flip-chip package, the semiconductor material 41 and electrical connection areas 47 are bonded facing towards the substrate 42, which in this case is a silicon substrate with circuitry and electrical connection areas 48 thereon. The electrical connection areas or pad areas on substrate 40 and substrate 42 are connected via conductive silicone particle adhesive 46 as disclosed herein. When necessary, the basis for The siloxane material 49 disclosed herein is electrically insulating and it provides improved adhesion and CTE properties. The silicone material 49 may have no granular material or may have particles such as oxide or nitride particles that do not provide conductive properties. The silicone particle adhesive 46 can be provided by screen printing, pin deposition or other suitable methods. The silicone material 49 may be a low molecular weight silicone or provided in liquid form with added solvent to fill the areas between the substrates via capillary action. The silicone particle adhesive 46 can be cured before adding the silicone material 49, or both materials can be cured together. Curing can optionally be via UV light or heat.

Additionally, as illustrated in FIG. 5, wire bonds 45 connect the circuitry on the silicon substrate 42 to the package substrate/support substrate substrate 44, which may be a ceramic substrate or other desired material. Adhesive 43 connects substrate 42 to substrate 44 and may be a silicone particle material as disclosed herein, preferably thermally conductive. Silicone material 49 may be optically transmissive in the visible (or UV) spectrum, or may be optically reflective for visible or UV light. If transmissive, a reflective layer may be provided on the substrate 42 to reflect light back in the other opposite direction to increase the efficiency of the LED lamp.

More specifically, with regard to the above-mentioned silicone particle composition, the composition is produced in the presence of a silicone polymer. Preferably, the polymer has a silica backbone with aryl (or alkyl) substituents and functional crosslinking substituents. The filler material is mixed with the silicone polymer. The filler material is preferably a granular material comprising particles having an average particle size of 100 microns or less, preferably 10 microns or less. A catalyst is added which reacts with the functional crosslinking groups in the silicone polymer when heat or UV light (or other activation method) is provided to the composition. Monomeric (or oligomeric) coupling agents are included in the composition, preferably having functional crosslinking groups that are also reactive upon application of heat or light as in silicone polymers. depends on composition Depending on the end use of the product, additional materials such as stabilizers, antioxidants, dispersants, adhesion accelerators, plasticizers, softeners and other possible components may also be added. Although solvents may be added, in a preferred embodiment the composition is solvent-free and a solvent-free viscous fluid, and the composition is stored and shipped as such.

As noted above, compositions made as disclosed herein include silicone polymers.

For the manufacture of siloxane polymers, a first compound of the following formula is provided: SiR ¹ _a R ² _4-a

wherein a is 1 to 3, R ¹ is a reactive group, and R ² is an alkyl or aryl group.

Also provided is a second compound having the formula: SiR ³ _b R ⁴ _c R ⁵ _4-(b+c)

Wherein R ³ is a crosslinking functional group, R ⁴ is a reactive group, and R ⁵ is an alkyl or aryl group, and wherein b=1 to 2, and c=1 to (4-b).

Together with the first compound and the second compound an optional third compound is provided for polymerization therewith. The third compound may have the following chemical formula: SiR ⁹ _f R ¹⁰ _g

wherein R ⁹ is a reactive group, and f=1 to 4, and wherein R ¹⁰ is an alkyl or aryl group and g=4-f.

The first compound, the second compound and the third compound may be provided in any order, and an oligomeric partially polymerized version of any of these compounds may be provided in place of the monomers mentioned above.

The first compound, the second compound and the third compound, as well as any compounds described below, if such compounds have more than one single type of "R" group, such as multiple aryl or alkyl groups, or multiple reactive group, or a plurality of cross-linking functional groups, etc., then independently select a plurality of R groups to be the same or different at each occurrence. For example, if the first compound is SiR ¹ ₂ R ² ₂ , multiple R ¹ groups are independently selected to be the same or different from each other. Likewise, multiple ^R2 groups are independently selected to be the same or different from each other. The same is true for any other compound mentioned herein unless expressly stated otherwise.

A catalyst is also provided. The catalyst can be a base catalyst, or other catalysts as mentioned below. The provided catalyst should be capable of polymerizing the first compound and the second compound together. As noted above, the order of adding the compounds and catalyst can be in any desired order. The various components provided together are polymerized to produce a silicone polymer material having the desired molecular weight and viscosity. After polymerization, particles, such as microparticles, nanoparticles, or other desired particles, are added, along with other optional components, such as coupling agents, catalysts, stabilizers, adhesion promoters, and the like. The components of the composition can be combined in any desired order.

More specifically, in one example, a siloxane polymer is prepared by polymerizing a first compound and a second compound, wherein the first compound has the formula: SiR ¹ _a R ² _4-a

wherein a is 1 to 3, R ¹ is a reactive group, and R ² is an alkyl or aryl group, and the second compound has the following chemical formula: SiR ³ _b R ⁴ _c R ⁵ _4-(b+c)

Wherein R ³ is a crosslinking functional group, R ⁴ is a reactive group, and R ⁵ is an alkyl or aryl group, and wherein b=1 to 2, and c=1 to (4-b).

The first compound may have 1 to 3 alkyl or aryl groups (R ² ) bonded to silicon in the compound. Combinations of different alkyl groups, combinations of different aryl groups or combinations of both alkyl and aryl groups are possible. In the case of an alkyl group, the alkyl group preferably contains 1 to 18, more preferably 1 to 14 and especially more preferably 1 to 12 carbon atoms. Shorter alkyl groups are envisioned, such as 1 to 6 carbons (eg, 2 to 6 carbon atoms). The alkyl group can be branched with one or more, preferably two C1 to C6 alkyl groups at the alpha position or the beta position. Specifically, the alkyl group is a lower alkyl group containing 1 to 6 carbon atoms, which optionally carries 1 to 3 substituents selected from methyl and halogen. Methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and tert-butyl are especially preferred. Cycloalkyl groups are also possible, such as cyclohexyl, adamantyl, norbornene or norbornyl.

If R is aryl, aryl may be phenyl, which optionally carries ¹ to 5 substituents selected from halogen, alkyl or alkenyl on the ring, or naphthyl, which optionally carries on the ring structure Carries 1 to 11 substituents selected from haloalkyl or alkenyl, optionally fluorinated (including perfluorinated or partially fluorinated). If the aryl group is a polycyclic aryl group, the polycyclic aryl group can be, for example, anthracene, naphthalene, phenanthrene, tetracene, which can carry 1-8 substituents as appropriate or can also optionally contain 1 to 12 substituents An alkyl, alkenyl, alkynyl, or aryl group of carbons is "spaced apart" from the silicon atom. Monocyclic structures such as phenyl groups can also be spaced from silicon atoms in this manner.

The siloxane polymer is prepared by polymerizing, preferably base catalyzed, between a first compound and a second compound. Optional additional compounds as set forth below may be included as part of the polymerization reaction.

The first compound may have any suitable reactive group R ¹ , such as hydroxyl, halogen, alkoxy, carboxyl, amine or acyloxy. If, for example, the reactive group in the first compound is an -OH group, more specific examples of the first compound may include silanediols, especially diphenylsilanediol, dimethylsilanediol , diisopropylsilanediol, di-n-propylsilanediol, di-n-butylsilanediol, di-tert-butylsilanediol, diisobutylsilanediol, phenylmethylsilanediol and dicyclohexylsilanediol.

The second compound may have any suitable reactive group R ⁴ , such as hydroxyl, halogen, alkoxy, carboxyl, amine or acyloxy, which may be the same as or different from the reactive group in the first compound. In one example, the reactive group is not -H in either the first compound or the second compound (or any compound that participates in polymerization to form a silicone polymer - such as the third compound, etc.), such that the resulting silicone The alkane polymer is free of any or substantially any H groups directly incorporated into the Si in the siloxane polymer. ^The group R5, if present entirely in the second compound, is independently alkyl or aryl, such as for the group R2 in the first ^compound . ^The alkyl or aryl group R5 may be the same as or different from the group R2 in the first ^compound .

The cross-linking reactive group R ³ of the second compound can be any functional group that can be cross-linked by acid, base, free radical or thermally catalyzed reaction. Such functional groups may be selected from, for example, any epoxy, oxetane, acrylate, alkenyl, alkynyl, vinyl and Si-H groups.

In the case of an epoxy group, it may be a cyclic ether having three ring atoms that can be crosslinked using acid, base and thermally catalyzed reactions. Examples of such epoxides containing crosslinking groups are glycidoxypropyl and (3,4-epoxycyclohexyl)ethyl, to name a few.

In the case of a propylene oxide group, it can be a cyclic ether with four ring atoms that can be crosslinked using acid, base and thermally catalyzed reactions. Examples of such propylene oxide-containing silanes include 3-(3-ethyl-3-oxetanylmethoxy)propyltriethoxysilane, 3-(3-methyl-3-oxetanylmethyl Oxy)propyltriethoxysilane, 3-(3-ethyl-3-oxetanylmethoxy)propyltrimethoxysilane or 3-(3-methyl-3-oxetanylmethoxy base) propyltrimethoxysilane (to name a few).

In the case of alkenyl groups, such groups may have preferably 2 to 18, more preferably 2 to 14 and especially more preferably 2 to 12 carbon atoms. The olefinic (ie, two carbon atoms bonded to a double bond) group is preferably located at position 2 or higher relative to the Si atom in the molecule. Branched alkenyl branched preferably at alpha or beta position with one and more preferably two C1 to C6 alkyl, alkenyl or alkynyl, optionally fluorinated or perfluorinated alkyl, alkenyl or alkynyl groups .

In the case of an alkynyl group, it may have preferably 2 to 18, more preferably 2 to 14 and especially more preferably 2 to 12 carbon atoms. Alkyne group (that is, to the two carbon atoms) are preferably located at positions 2 or higher relative to Si atoms or M atoms in the molecule. Branched chain alkynyl is preferably branched at the alpha position or the beta position with one and more preferably two C1 to C6 alkyl, alkenyl or alkynyl, optionally perfluorinated alkyl, alkenyl or alkynyl groups.

In the case of mercapto, it may be any organosulfur compound containing a carbon-bonded sulfhydryl group. Examples of mercapto-containing silanes are 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

The reactive group in the second compound may be an alkoxy group. The alkyl residue of an alkoxy group may be straight-chain or branched. Preferably, the alkoxy group consists of lower alkoxy groups having 1 to 6 carbon atoms (such as methoxy, ethoxy, propoxy and tert-butoxy). Specific examples of the second compound are silanes, especially such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane , 3-(trimethoxysilyl)propyl methacrylate, 3-(trimethoxysilyl)propyl acrylate, (3-glycidyloxypropyl)trimethoxysilane or 3-glycidyloxy Propyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane.

The third compound may be provided together with the first compound and the second compound for polymerization therewith. The third compound may have the following chemical formula: SiR ⁹ _f R ¹⁰ _g

Wherein R ⁹ is a reactive group, and f=1 to 4, and R ¹⁰ is an alkyl or aryl group, and g=4-f.

One such example is tetramethoxysilane. Other examples include, inter alia, phenylmethyldimethoxysilane, trimethylmethoxysilane, dimethyldimethoxysilanesilane, vinyltrimethoxysilane, allyltrimethoxysilane, methyltrimethoxysilane Oxysilane, Methyltriethoxysilane, Methyltripropoxysilane, Propylethyltrimethoxysilane, Ethyltriethoxysilane, Vinyltrimethoxysilane, Vinyltriethoxysilane silane.

Although the polymerization of the first compound and the second compound can be carried out using an acid catalyst, a base catalyst is preferred. The base catalyst used in the base-catalyzed polymerization between the first compound and the second compound can be any suitable basic compound. Examples of such basic compounds are, inter alia, any amine, such as triethylamine, and any barium hydroxide, such as barium hydroxide, barium hydroxide monohydrate, barium hydroxide octahydrate. Other basic catalysts include magnesium oxide, calcium oxide, barium oxide, ammonia, ammonium perchlorate, sodium hydroxide, potassium hydroxide, imidazole or n-butylamine. In a particular example, the base catalyst is Ba(OH) ₂ . The base catalyst may be provided in a weight % of less than 0.5% relative to the first compound and the second compound together, or in a lower amount, such as in a weight % of less than 0.1%.

Polymerization can be carried out in a melt phase or in a liquid medium. The temperature is in the range of about 20°C to 200°C, usually about 25°C to 160°C, especially about 40°C to 120°C. Generally, polymerizations are carried out at ambient pressure and the maximum temperature is set by the boiling point of any solvent used. Polymerization can be performed under reflux conditions. Other pressures and temperatures are also possible. The molar ratio of the first compound to the second compound may be 95:5 to 5:95, especially 90:10 to 10:90, preferably 80:20 to 20:80. In a preferred embodiment, the molar ratio of the first compound to the second compound (or second compound plus other compounds involved in the polymerization reaction - see below) is at least 40:60, or even 45:55 or higher.

In one example, the first compound has an -OH group as a reactive group group and the second compound has an alkoxy group as a reactive group. Preferably, the total number of -OH groups is no greater than the total number of reactive groups (e.g. alkoxy groups) in the second compound with respect to the amount of first compound added, and is preferably less than (or The total number of reactive groups in the second compound plus any other compound added with the alkoxy group, such as added tetramethoxysilane or other third compound involved in the polymerization reaction (as mentioned herein) . In cases where alkoxy groups outnumber hydroxyl groups, all or substantially all -OH groups will react and be removed from the siloxane, such as methanol (if the alkoxysilane is a methoxysilane), ethanol (if the alkoxysilane Base silane is ethoxysilane) and so on. Although the number of -OH groups in the first compound and the number of reactive groups (preferably other than -OH groups) in the second compound may be substantially the same, it is preferred that the reactive The total number of groups exceeds in number the -OH groups in the first compound by 10% or more, preferably by 25% or more. In some embodiments, the number of reactive groups of the second compound exceeds the -OH groups of the first compound by 40% or more, or even 60% or more, 75% or more, or up to 100% or more . Methanol, ethanol and other by-products of the polymerization reaction (depending on the selected compounds) are removed after polymerization, preferably evaporated in a drying chamber.

The silicone polymer obtained has any desired (weight average) molecular weight, such as 500 grams/mole to 100,000 grams/mole. The molecular weight can be at the lower end of this range (e.g., 500 g/mole to 10,000 g/mole or more preferably 500 g/mole to 8,000 g/mole) or the molecular weight of the organosiloxane material can be at the upper end of this range ( Such as 10,000 g/mol to 100,000 g/mol or more preferably 15,000 g/mol to 50,000 g/mol). It may be desirable to mix a polymeric organosiloxane material having a lower molecular weight with an organosiloxane material having a higher molecular weight.

Depending on the end desired use of the polymer, the silicone polymer obtained can be Then combine with additional components. Preferably, the silicone polymer is combined with a filler to form a composition, such as a particulate filler having an average particle size of less than 100 microns, preferably less than 50 microns, including particles less than 20 microns. Additional components may be part of the composition, such as catalysts or curing agents, one or more coupling agents, dispersants, antioxidants, stabilizers, adhesion accelerators, and/or other desired components, depending on the silicone material the final desired use. In one example, a reducing agent that can reduce the oxidized surface to its metallic form is included. The reducing agent can remove oxidation from the particle, where the particle is a metal particle with surface oxidation, and/or remove oxidation, such as from a metal bond pad or other metal or conductive area that has oxidized, to improve the silicone particle material and its Electrical connection between deposited or adhered surfaces. Reducing or stabilizing agents may include ethylene glycol, β-D-glucose, polyethylene oxide, glycerol, 1,2-propylene glycol, N,N dimethylformamide, poly-sodium acrylate (PSA), β-cyclodextrin of polyacrylic acid, dihydroxybenzene, polyvinyl alcohol, 1,2-propanediol, hydrazine, hydrazine sulfate, sodium borohydride, ascorbic acid, hydroquinone family, gallic acid, pyrogallol, ethylene diol Aldehydes, Acetaldehyde, Glutaraldehyde, Aliphatic Dialdehyde Family, Paraldehyde, Tin Powder, Zinc Powder, Formic Acid. Additives such as stabilizers, for example antioxidants such as Irganox (as mentioned below) or diazine derivatives may also be added.

Cross-linking silicone or non-silicon resins and oligomers can be used to enhance the cross-linking between silicone polymers. The functionality of the added cross-linked oligomer or resin is selected by the functionality of the silicone polymer. If, for example, epoxy-based alkoxysilanes are used during polymerization of the silicone polymer, epoxy-functional oligomers or resins may be used. The epoxy oligomer or resin can be any difunctional, trifunctional, tetrafunctional or higher functional epoxy oligomer or resin. Examples of such epoxy oligomers or resins may be 1,3-bis-2-(3,4-epoxycyclohexyl)ethyl 1,1,3,3-tetramethyldisiloxane, 1, 3-Diglycidoxypropyl 1,1,3,3-tetramethyldisiloxane, bis(3,4-epoxycyclohexylmethyl) adipate, 3,4-cyclohexanecarboxylate Oxycyclohexyl methyl ester, 1,4-cyclohexanedimethanol diglycidyl ether, bisphenol A diglycidyl ether, 1,2-cyclohexanedicarboxylate diglycidyl ether, to name a few.

A curing agent added to the final formulation is any compound that can initiate and/or accelerate the curing process of the functional groups in the silicone polymer. These curing agents may be thermally and/or UV activated (eg thermal acid in case of thermally activated polymerization or photoinitiator in case of UV activated). The crosslinking groups in the silicone polymers as described above are preferably epoxy, propylene oxide, acrylate, alkenyl or alkynyl. The curing agent is selected based on the crosslinking groups in the silicone polymer.

In one embodiment, curing agents for epoxy and propylene oxide groups may be selected from nitrogen-containing curing agents that exhibit blocked or reduced activity, such as primary and/or secondary amines. The definition "primary or secondary amine exhibiting blocked or reduced reactivity" shall mean either incapable or having only a very low ability to react with the resin components due to chemical or physical blocking, but may The reactivity of the amine is regenerated after release of the amine, for example by melting it at elevated temperature, by removing the sheath or coating, by the action of pressure or ultrasound or other energy types, initiating the separation of the resin components The amines of the curing reaction.

Examples of heat-activatable curing agents include at least one organoborane or a complex of a borane and at least one amine. The amine can be any type that complexes the organoborane and/or borane and can decomplex to release the organoborane or borane if necessary. Amines can include a variety of structures, such as any primary or secondary amine or polyamines containing primary and/or secondary amines. Organoboranes may be selected from alkylboranes. An example of such a particularly preferred borane is boron trifluoride. Suitable amine/(organo)borane complexes are available from commercial suppliers such as King Industries, Air products, and ATO-Tech. source.

Other thermally activated curing agents for epoxy groups are thermal acid generators, which release strong acids at high temperatures to catalyze the crosslinking reaction of epoxy groups. Such thermal acid generators can be, for example, any onium salts with complex anions of the BF ₄ ^- , PF ₆ ^- , SbF ₆ ^- , CF ₃ SO ₃ ^- and (C ₆ F ₅ ) ₄ B ^-type , such as sulfonium salts and iodonium salt. Commercial examples of such thermal acid generators are K-PURE CXC-1612 and K-PURE CXC-1614 manufactured by Kings Industries.

Additionally, in the case of polymer-containing epoxides and/or propylene oxides, curing agents, co-curing agents, catalysts, initiators or other additives designed to participate in or facilitate the curing of the adhesive formulation may be used, such as Acid anhydride, amine, imidazole, mercaptan, carboxylic acid, phenol, dicyandiamide, urea, hydrazine, hydrazine, amino-formaldehyde resin, melamine-formaldehyde resin, quaternary ammonium salt, quaternary phosphonium salt, triaryl sulfide onium salts, diaryliodonium salts, diazonium salts, and the like.

For acrylates, alkenyl and alkyne crosslinking group curing agents can be heat or UV activated. Examples of thermal activation are peroxides and azo compounds. Peroxides are compounds containing labile oxygen-oxygen single bonds that are readily resolved into reactive free radicals via hemolytic cleavage. Azo compounds have R-N=N-R functional groups that can be decomposed into nitrogen gas and two organic radicals. In both cases, free radicals can catalyze the polymerization of acrylate, alkenyl and alkyne linkages. Examples of peroxides and azo compounds are two-tert-butyl peroxide, 2,2-bis(tert-butyl peroxy)butane, tert-butyl peracetate, 2,5-bis( tert-butylperoxy)-2,5-dimethyl-3-hexyne, dicumyl peroxide, benzoyl peroxide, di-tert-amyl peroxide, peroxybenzoic acid Tertiary butyl ester, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-carboxamidinopropane) dihydrochloride, diphenyldiazene, Diethyl azodicarboxylate and 1,1'-azobis(cyclohexanecarbonitrile), to name a few.

Photoinitiators are compounds that decompose into free radicals when exposed to light and thus can promote the polymerization of acrylate, alkenyl, and alkynyl compounds. Commercial examples of such photoinitiators are Irgacure 149, Irgacure 184, Irgacure 369, Irgacure 500, Irgacure 651, Irgacure 784, Irgacure, manufactured by BASF. Jiagu 819, Yanjiagu 907, Yanjiagu 1700, Yanjiagu 1800, Yanjiagu 1850, Yanjiagu 2959, Yanjiagu 1173, Yanjiagu 4265.

One method of incorporating a curing agent into the system is to attach the curing agent or a functional group that can act as a curing agent to the silane monomer. Therefore, the curing agent will accelerate the curing of the silicone polymer. Examples of these types of curing agents attached to silane monomers are γ-imidazolylpropyltriethoxysilane, γ-imidazolylpropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3 -Mercaptopropyltriethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride, 3-(trimethoxysilyl)propylsuccinic anhydride, 3-aminopropyltrimethoxy Silane and 3-Aminopropyltriethoxysilane (to name a few).

The accelerator can then be part of the composition and can be any suitable compound that can enhance the adhesion between the cured product and the surface of the coated product. The most commonly used adhesion accelerators are functional silanes, which contain alkoxysilanes and 1 to 3 functional groups. Examples of adhesion promoters used in die attach products may be octyltriethoxysilane, mercaptopropyltriethoxysilane, cyanopropyltrimethoxysilane, 2-(3,4-cyclo Oxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(trimethoxysilyl)propyl methacrylate, 3-(trimethyl (oxysilyl)propyl acrylate, (3-glycidyloxypropyl)trimethoxysilane or 3-glycidyloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane Oxysilane and 3-Acryloxypropyltrimethoxysilane.

The polymeric siloxane formed will have a [Si-O-Si-O]n repeating backbone, on which The organofunctionality depends on the silicon-containing starting material. However, it is also possible to achieve [Si-O-Si-C]n or even [Si-O-Me-O]n (where Me is a metal) backbone.

To obtain the [Si-O-Si-C] backbone, a chemical with the following formula: R ² _3-a R ¹ _a SiR ¹¹ SiR ¹ _b R ² _3-b

wherein a is 1 to 3, b is ¹ to ³ , R is a reactive group as explained above, R is alkyl, alkenyl, alkynyl, alcohol, carboxylic acid, dicarboxylic acid, aryl, poly Aryl, polycycloalkyl, heterocyclic aliphatic, heterocyclic aromatic, and R ¹¹ is independently alkyl or aryl, or an oligomer whose molecular weight is less than 1000 grams/mole; The first compound, the second compound and the third compound or any combination thereof are polymerized together.

Examples of such compounds are 1,2-bis(dimethylhydroxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(dimethoxymethylsilane base) ethane, 1,2-bis(methoxydimethylsilyl)ethane, 1,2-bis(triethoxysilyl)ethane, 1,3-bis(dimethylhydroxysilane base) propane, 1,3-bis(trimethoxysilyl)propane, 1,3-bis(dimethoxymethylsilyl)propane, 1,3-bis(methoxydimethylsilyl) Propane, 1,3-bis(triethoxysilyl)propane, 1,4-bis(dimethylhydroxysilyl)butane, 1,4-bis(trimethoxysilyl)butane, 1, 4-bis(dimethoxymethylsilyl)butane, 1,4-bis(methoxydimethylsilyl)butane, 1,4-bis(triethoxysilyl)butane, 1,5-bis(dimethylhydroxysilyl)pentane, 1,5-bis(trimethoxysilyl)pentane, 1,5-bis(dimethoxymethylsilyl)pentane, 1 ,5-bis(methoxydimethylsilyl)pentane, 1,5-bis(triethoxysilyl)pentane, 1,6-bis(dimethylhydroxysilyl)hexane, 1 ,6- Bis(trimethoxysilyl)hexane, 1,6-bis(dimethoxymethylsilyl)hexane, 1,6-bis(methoxydimethylsilyl)hexane, 1,6 -Bis(triethoxysilyl)hexane, 1,4-bis(trimethoxysilyl)benzene, bis(trimethoxysilyl)naphthalene, bis(trimethoxysilyl)anthracene, bis(trimethyl Oxysilyl)phenanthrene, bis(trimethoxysilyl)norbornene, 1,4-bis(dimethylhydroxysilyl)benzene, 1,4-bis(methoxydimethylsilyl)benzene and 1,4-bis(triethoxysilyl)benzene (to name a few).

In one embodiment, in order to obtain the [Si-O-Si-C] backbone, a compound having the formula R ⁵ _3-(c+d) R ⁴ _d R ³ _c SiR ¹¹ SiR ³ _e R ⁴ _f R ⁵ _3-(e+f)

Wherein ^R3 is a crosslinking functional group, ^R4 is a reactive group, and ^R5 is an alkyl, alkenyl, alkynyl, alcohol, carboxylic acid, dicarboxylic acid, aryl, polyaryl, polycycloalkyl , heterocyclic aliphatic group, heterocyclic aromatic group, R ¹¹ is independently alkyl or aryl, and wherein c=1 to 2, d=1 to (3-c), e=1 to 2, and f =1 to (3-e), or oligomers thereof with a molecular weight of less than 1000 g/mole, polymerized together with the first compound, the second compound, the third compound, or any combination thereof as mentioned herein .

Examples of such compounds are 1,2-bis(vinyldimethoxysilyl)ethane, 1,2-bis(ethynyldimethoxysilyl)ethane, 1,2-bis(ethynyl Dimethoxy)ethane, 1,2-bis(3-glycidoxypropyldimethoxysilyl)ethane, 1,2-bis[2-(3,4-epoxycyclohexyl) Ethyldimethoxysilyl]ethane, 1,2-bis(propylmethacrylatedimethoxysilyl)ethane, 1,4-bis(vinyldimethoxysilyl)benzene, 1,4- Bis(ethynyldimethoxysilyl)benzene, 1,4-bis(ethynyldimethoxysilyl)benzene, 1,4-bis(3-glycidyloxypropyldimethoxysilyl) ) benzene, 1,4-bis[2-(3,4-epoxycyclohexyl)ethyldimethoxysilyl]benzene, 1,4-bis(propyl methacrylate dimethoxysilyl) Benzene (to name a few).

In one embodiment, the formula R ¹ _a R ² _b R ³ _3-(a+b) Si-O-SiR ² ₂ -O-Si R ¹ _a R ² _b R ³ _3-(a+b) ^A siloxane monomer wherein R1 is ^a reactive group as explained above, R2 is an alkyl or aryl group as explained above, ^R3 is a crosslinking functional group as explained above, and a=0 to 3 , b=0 to 3, polymerized with the previously mentioned silanes or added as additives to the final formulation. Examples of such compounds are 1,1,5,5-tetramethoxy-1,5-dimethyl-3,3-diphenyltrisiloxane, 1,1,5,5-tetramethoxy 1,3,3,5-tetraphenyltrisiloxane, 1,1,5,5-tetraethoxy-3,3-diphenyltrisiloxane, 1,1,5,5 -Tetramethoxy-1,5-divinyl-3,3-diphenyltrisiloxane, 1,1,5,5-tetramethoxy-1,5-dimethyl-3,3 -Diisopropyltrisiloxane, 1,1,1,5,5,5-hexamethoxy-3,3-diphenyltrisiloxane, 1,5-dimethyl-1,5- Diethoxy-3,3-diphenyltrisiloxane, 1,5-bis(mercaptopropyl)-1,1,5,5-tetramethoxy-3,3-diphenyltrisiloxane Oxane, 1,5-divinyl-1,1,5,5-tetramethoxy-3-phenyl-3-methyltrisiloxane, 1,5-divinyl-1,1, 5,5-tetramethoxy-3-cyclohexyl-3-methyltrisiloxane, 1,1,7,7-tetramethoxy-1,7-divinyl-3,3,5, 5-tetramethyltetrasiloxane, 1,1,5,5-tetramethoxy-3,3-dimethyltrisiloxane, 1,1,7,7-tetraethoxy-3, 3,5,5-tetramethyltetrasiloxane, 1,1,5,5-tetraethoxy-3,3-dimethyltrisiloxane, 1,1,5,5-tetramethoxy Base-1,5-[2-(3,4-epoxycyclohexyl)ethyl]-3,3-diphenyltrisiloxane, 1,1,5,5-tetramethoxy-1, 5-(3-glycidyloxypropyl)-3,3-diphenyltrisiloxane, 1,5-dimethyl-1,5-dimethoxy-1,5-2-(3 ,4-epoxycyclohexyl)ethyl]-3,3-diphenyltrisiloxane, 1,5-dimethyl-1,5-dimethoxy-1,5-(3-glycidyl oxypropyl)-3,3-diphenyltrisiloxane (to name a few).

An additive added to the composition (after polymerizing the siloxane material as indicated above) may be a silane compound having the formula: R ¹ _a R ² _b SiR ³ _4-(a+b)

Where R1 is ^a reactive group, such as hydroxyl, alkoxy or acetyloxy, R2 is an alkyl or aryl group, ^R3 is a crosslinking ^compound , such as epoxy, propylene oxide, alkenyl, acrylic Ester or alkynyl, a=0 to 1 and b=0 to 1.

Examples of such additives are tris-(3-glycidoxypropyl)phenylsilane, tris-[2-(3,4-epoxycyclohexyl)ethyl]phenylsilane, tris-(3-methyl Acryloxy)phenylsilane, Tris-(3-acryloxy)phenylsilane, Tetrakis-(3-glycidyloxypropyl)silane, Tetrakis-[2-(3,4-epoxy Cyclohexyl)ethyl]silane, tetrakis-(3-methacryloxy)silane, tetrakis-(3-acryloxy)silane, tris-(3-glycidyloxypropyl)-p-tolylsilane , Tris-[2-(3,4-epoxycyclohexyl)ethyl]p-tolylsilane, Tris-(3-methacryloxy)p-tolylsilane, Tris-(3-acryloxy ) p-tolylsilane, tris-(3-glycidyloxypropyl)hydroxysilane, tris-[2-(3,4-epoxycyclohexyl)ethyl]hydroxysilane, tris-(3-methylpropene Acryloxy)hydroxysilane, Tris-(3-acryloxy)hydroxysilane.

The additive can also be any organic or silicone polymer, which may or may not react with the primary polymer matrix, thus acting as a plasticizer, softener or matrix modifier, such as silicone. The additives may also be inorganic polycondensates such as SiOx, TiOx, AlOx, TaOx, HfOx, ZrOx, SnOx, polysilazanes.

The particulate filler may be a conductive material such as carbon black, graphite, graphene, gold, silver, copper, platinum, palladium, nickel, aluminum, silver-plated copper, silver-plated aluminum, bismuth, tin, bismuth-tin alloys, silver-plated Fiber, nickel-plated copper, silver-nickel-plated copper, gold-plated copper, gold-nickel-plated copper, or polymers that can be gold-plated, silver-gold, silver, nickel, tin, platinum, titanium, such as polyacrylate, Polystyrene or silicone, but not limited to. The filler can also be a semiconductor material, such as silicon, n-type or p-type doped silicon, GaN, InGaN, GaAs, InP, SiC, but not limited thereto. Furthermore, the filler may be quantum dots or plasmonic particles or phosphor particles. Other semiconductor particles or quantum dots, such as Ge, GaP, InAs, CdSe, ZnO, ZnSe, _TiO2 , ZnS, CdS, CdTe, etc. are also possible.

The filler may be particles, which are any suitable metal or semi-metal particles, such as those selected from gold, silver, copper, platinum, palladium, indium, iron, nickel, aluminum, carbon, cobalt, strontium, zinc, molybdenum, titanium, Tungsten, silver-plated copper, silver-plated aluminum, bismuth, tin, bismuth-tin alloys, silver-plated fibers, or alloys or combinations thereof. Metal particles, as well as semimetals and metalloids, are envisioned as transition metal particles (whether early transition metals or late transition metals). Particles of semimetals or metalloids are envisioned, such as arsenic, antimony, tellurium, germanium, silicon, and bismuth.

Alternatively, it may be a non-conductive material such as silicon dioxide, quartz, aluminum oxide, aluminum nitride, aluminum nitride coated with silicon dioxide, barium sulfate, aluminum oxide trihydrate, boron nitride, and the like. Fillers can be in the form of particles or flakes, and can be micron or nano sized. It is possible for the filler to include particles of ceramic compounds which are nitrides, oxynitrides, carbides and oxycarbides of metals or semimetals. In particular, the filler may be particles of silicon, zinc, aluminum, yttrium, ytterbium, tungsten, titanium silicon, titanium, antimony, calcium, nickel, nickel cobalt, molybdenum, magnesium, manganese, lanthanides, Ceramic particles of oxides of iron, indium tin, copper, cobalt aluminum, chromium, cesium or calcium.

Also possible are particles comprising carbon and selected from carbon black, graphite, graphene, diamond, silicon carbonitride, titanium carbonitride, carbon nanobuds and carbon nanotubes. The filler particles can be carbide particles, such as iron carbide, silicon carbide, cobalt carbide, carbon Tungsten carbide, boron carbide, zirconium carbide, chromium carbide, titanium carbide or molybdenum carbide. The particles may alternatively be nitride particles such as aluminum nitride, tantalum nitride, boron nitride, titanium nitride, copper nitride, molybdenum nitride, tungsten nitride, iron nitride, silicon nitride, indium nitride, Gallium Nitride or Carbon Nitride.

Particles of any suitable size can be used depending on the end application. In many cases, small particles are used with an average particle size of less than 100 microns, and preferably less than 50 microns or even 20 microns. Submicron particles are also envisioned, such as those smaller than 1 micron, or for example 1 nm to 500 nm, such as smaller than 200 nm, such as 1 nm to 100 nm, or even smaller than 10 nm. In other examples, particles are provided having an average particle size of 5 nm to 50 nm, or 15 nm to 75 nm, less than 100 nm, or 50 nm to 500 nm. Particles that are not elongated, such as substantially spherical or square, or flakes with a flattened disk appearance (with smooth or rough edges) are possible, as are elongated whiskers, cylinders, wires, and other elongated particles, such as those with 5: 1 or larger, or particles with an aspect ratio of 10:1 or larger. Very elongated particles with extremely high aspect ratios, such as nanowires and nanotubes are also possible. The high aspect ratio of the nanowires or nanotubes can be 25:1 or greater, 50:1 or greater, or even 100:1 or greater. The average particle size of nanowires or nanotubes refers to the smallest dimension (width or diameter), since the length can be quite long, even up to several centimeters long. As used herein, the term "average particle size" refers to the D50 value at the cumulative volume distribution curve at which 50% by volume of the particles have a diameter smaller than the stated value.

The particles may be a mixture of particles as mentioned elsewhere herein, wherein a first set of particles having an average particle size greater than 200 nm is provided together with a second set of particles having an average particle size less than 200 nm, e.g., wherein the average particle size of the first set The particle size is greater than 500 nm and the average particle size of the second set is less than 100 nm (eg, the average particle size of the first set is greater than 1 micron, the particle size of the second set is less than 50 nm, or even less than 25 nm). The melting point of the smaller particles is lower than that of the larger particles, and the smaller particles are smaller than Melting or sintering at the temperature at which particles of the same material of the same size are melted or sintered. In one example, the smaller particles have an average particle size of less than 1 micron and melt or sinter at a temperature less than the bulk temperature of the same material. Depending on the selected particle material and average particle size, melting and sintering temperatures will vary.

As an example, very small silver nanoparticles can be melted below 120°C and sintered at even lower temperatures. Thus, if desired, the melting or sintering temperature of the smaller particles can be at or below the polymer solidification temperature to form a melting or sintering linking the larger particles together prior to complete crosslinking and curing of the silicone polymer material. Web of Particles. In one example, the smaller particles are melted or sintered with the larger particles at a temperature below 130°C, such as below 120°C, or even sintered at a temperature below 110°C, while the silicone material is sintered at a higher temperature undergoes substantial crosslinking at temperatures such as substantially sintering or melting below 110°C, but substantially polymerizing above 110°C (or, for example, substantially sintering or melting below 120°C (or 130°C) but at Substantial polymerization at greater than 120°C (or 130°C). Sintering or melting of the smaller particles prior to substantial polymerization of the silicone material allows the formed metal "mesh" to have greater interconnectivity, which increases the final conductivity of the cured layer. Substantial sintering or substantial polymerization of the smaller particles prior to melting reduces the amount of metal "grid" formed and reduces the conductivity of the final solidified layer. Of course, it is also possible to provide only particles with a smaller average particle size (e.g. sub-micron size), which still achieve lower sintering and melting points compared to the same bulk (or the same particles, e.g., with an average particle size greater than 1 micron). benefit.

To enhance coupling with fillers and silicone polymers, coupling agents can be used. This coupling agent will increase the bond between the filler and the polymer and thus can increase the thermal and/or electrical conductivity of the final product. The coupling agent can be any silane monomer with the following formula: R ¹³ _h R ¹⁴ _i SiR ¹⁵ _j

wherein R ¹³ is a reactive group such as halogen, hydroxyl, alkoxy, acetyl or acetyloxy, R ¹⁴ is alkyl or aryl, and R ¹⁵ is such as epoxy, anhydride, cyano, Functional groups of propylene oxide, amine, mercapto, allyl, alkenyl or alkynyl; h=0 to 4, i=0 to 4, j=0 to 4 and h+i+j=4.

The coupling agent can be mixed directly with the filler, silicone polymer, curing agent, and additives when making the final product or the filler particles can be treated with the coupling agent before it is mixed with the particles.

If the particles are treated with a coupling agent before use in the final formulation, different methods can be used, such as deposition from alcoholic solutions, deposition from aqueous solutions, bulk deposition onto fillers, and anhydrous liquid phase deposition. In deposition from an alcoholic solution, an alcohol/water solution is prepared and the pH of the solution is adjusted to slightly acidic (pH 4.5-5.5). The silane was added to this solution and mixed for a few minutes to allow partial hydrolysis. Next, filler particles are added and the solution is mixed from room temperature to reflux temperature for various time periods. After mixing, the particles were filtered, rinsed with ethanol and dried in an oven to obtain surface-treated particles with a coupling agent. Deposition from an aqueous solution is similar to deposition from an alcoholic solution, but pure water is used instead of alcohol as the solvent. If non-amine functionalization is used, the pH is adjusted again by acid. After mixing the particles with the water/silane mixture, the particles were filtered, rinsed and dried.

The bulk deposition method is a method in which a silane coupling agent is mixed with a solvent without any water or pH adjustment. The filler particles are coated with the silanol solution using different methods like spray coating and then dried in an oven.

In anhydrous liquid deposition, the silane is mixed with an organic solvent such as toluene, tetrahydrofuran or a hydrocarbon, the filler particles are refluxed in this solution and the additional solvent is removed by vacuum or filtration. The particles can also be subsequently dried in an oven, but this is sometimes not required due to the direct reaction between the particles and the filler under reflux conditions.

Examples of such silane coupling agents are bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, allyltrimethoxysilane, N-(2-aminoethyl)-3- Aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3- Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, (N-trimethoxysilylpropyl)polyethylenediimine, trimethoxysilylpropyldiethylenetri Amine, phenyltriethoxysilane, phenyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 1-trimethoxysilyl-2 (p, m-chloromethyl) phenylethane, 2- (3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, propylisocyanate triethoxysilane, bis[3-(triethoxy Silyl)propyl]tetrasulfide, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 2- (Diphenylphosphino)ethyltriethoxysilane, 1,3-divinyltetramethyldisilazane, hexamethyldisilazane, 3-(N-styrylmethyl-2- Aminoethylamino)propyltrimethoxysilane, N-(triethoxysilylpropyl)urea, 1,3-divinyltetramethyldisilazane, vinyltriethoxysilane and Vinyltrimethoxysilane (just to name a few).

Depending on the type of particles added, the siloxane-particle cured final product can be a thermally conductive layer or film, such as after final thermal or UV curing with greater than 0.5 watts/meter. Thermal conductivity of Kelvin (W/(m.K)). Depending on the particle type chosen, higher thermal conductivity materials are possible. The metal particles in the siloxane composition can produce a thermal conductivity greater than 2.0 W/m. Kerven, such as greater than 4.0 W/m. kelvin or something To greater than 10.0 W/m. Kerven's cured final film. Depending on the end application, higher thermal conductivities, such as greater than 50.0 W/m, may be required. Kerven, or even greater than 100.0 W/m. Kelvin. In other applications, however, the particles may be selected to produce materials with lower thermal conductivity where necessary, such as where the silicone particle material is an optional transmissive layer as mentioned above.

In addition, the final cured product may have a low resistivity, such as less than 1×10 ^-3 Ω, if necessary. m, preferably less than 1×10 ^-5 Ω. m, and preferably less than 1×10 ^-7 Ω. m. In addition, the sheet resistance of the deposited film is preferably less than 100,000, more preferably less than 10,000. However, many desired end uses of the material can have high resistivities.

In some cases, particularly where the composition will be used in devices requiring optical characteristics, it is more likely that the material will desirably be highly transmissive in the visible spectrum, although in some cases it may be desirable for the final cured silicone to have optically absorptive properties. Light in the visible spectrum (or in the spectrum in which the final device will be operated), or will desirably be highly reflective. As an example of a transparent material, a final cured layer having a thickness of 1 micron to 50 microns will transmit at least 85%, or preferably at least 90%, more preferably at least 92.5% and most preferably at least 95%, of visible light normally incident thereon. As an example of a reflective layer, the final cured layer can reflect at least 85% of light incident on it, preferably at least 95% of light incident on it at an angle of 90 degrees.

The materials of the invention may also contain stabilizers and/or antioxidants. These compounds are added to protect the material from degradation caused by reactions with oxygen induced by substances such as heat, light, or residual catalyst from raw materials.

Among the applicable stabilizers or antioxidants included herein are high molecular weight hindered phenols and polyfunctional phenols, such as sulfur and phosphorus containing phenols. Hindered phenols are well known to those skilled in the art and can be characterized as also containing Phenolic compounds of sterically bulky free radicals. Specifically, the tert-butyl group is generally substituted on the benzene ring at least one ortho position relative to the phenolic hydroxyl group. The presence of these sterically bulky substituted radicals near the hydroxyl group serves to slow down its stretching frequency and correspondingly its reactivity; this steric hindrance thus provides the phenolic compound with its stabilizing properties. Representative hindered phenols include: 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-benzene; tetrakis-3( 3,5-di-tert-butyl-4-hydroxyphenyl)-propionyl pentaerythritol; 3(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid octaalkyl esters; 4,4'-methylenebis(2,6-tert-butyl-phenol); 4,4'-thiobis(6-tert-butyl-o-cresol); 2,6- Di-tert-butylphenol; 6-(4-hydroxyphenoxy)-2,4-bis(n-octyl-thio)-1,3,5 triazine; 3,5-di-tert-butyl di-n-octylthio)ethyl-4-hydroxy-benzoate; and sorbitol hexa[3-(3,5-di-tert-butyl-4-hydroxy-phenyl)-propionate]. Commercial examples of antioxidants are, for example, Encanox 1035, Encanox 1010, Encanox 1076, Encanox 1098, Encanox 3114, Encanox PS800, Encanox, manufactured by BASF Kesi PS802, Yanjia Knox 168.

Depending on the end use of the product, the weight ratio between silicone polymer and filler is between 100:0 and 5:95. The ratio between silicone polymer and cross-linked silicone or non-silicon resin or oligomer is between 100:0 and 75:25. The amount of curing agent calculated from the amount of silicone polymer is 0.1% to 20%. The amount of adhesion accelerator is 0 to 10% based on the total amount of the formulation. Antioxidants are present in amounts of 0 to 5% based on the total weight of the formulation.

Silicone-particle compositions can be used in various fields. It can be used as electronic or optoelectronic packaging, LED and OLED front-end and back-end processing, 3D, photovoltaic and display metallization, soldering instead of solder bumps in semiconductor packaging, printed electronic devices, OLED low work function cathode Inks, ITO replacement inks, metal grids and others Adhesives or sealants in electrodes, high-resolution photovoltaic pastes, LMO cathode pastes, photovoltaics, power electronics and EMI, touch sensors and other displays, thermal or UV curable sealants or dielectrics ( Just to name a few).

Depending on the curing mechanism and the type of catalyst activation, the final formulation is usually cured by heating the material to a higher temperature. For example, if a thermal acid generator is used, the material is placed in an oven for a specified period of time. Also possible is curing by means of electromagnetic radiation, such as UV light.

The molecular weight of the siloxane polymer formed by polymerizing the first compound and the second compound is about 300 g/mole to 10,000 g/mole, preferably about 400 g/mole to 5,000 g/mole, and more preferably About 500 g/mol to 2,000 g/mol. The polymer is combined with particles of any desired size, preferably with an average particle size of less than 100 microns, more preferably less than 50 microns, or even less than 20 microns. The silicone polymer is added at 10% to 90% by weight, and the particles are added at 1% to 90% by weight. If the end use of the silicone material requires optical clarity, the particles may be ceramic particles added at a lower weight %, such as 1 to 20 weight %. If conductivity is required, such as when using siloxane materials in semiconductor packaging, the particles can be metal particles added at 60% to 95% by weight.

The polymerization of the first compound and the second compound is carried out, and the particles are mixed therewith to form a viscosity of 50 MPa-s to 100,000 MPa-s, preferably 1000 MPa-s to 75,000 MPa-s and more preferably 5000 MPa - Viscous fluids up to 50,000 MPa-s. Viscosity can be measured by a viscometer, such as a Brookfield viscometer or a Cole-Parmer viscometer, which rotates a disc or cylinder in a fluid sample and measures against Torque required to induce viscous resistance of motion. Can be any desired speed, such as 1rpm to 30rpm, preferably 5rpm, and preferably in the material Rotate while measuring at 25°C.

After polymerization, any additional desired components may be added to the composition, such as particles, coupling agents, curing agents, and the like. The composition is shipped to the customer as a viscous material in a container shipped at ambient temperature without cooling or freezing. As a final product, the material can be applied in a variety of applications as mentioned above, usually heat cured or UV cured to form a solid cured polymeric silicone layer.

Compositions as disclosed herein are preferably free of any substantial solvent. Solvents may be added extemporaneously, such as for mixing curing agents or other additives with the polymeric viscous material. In this case, for example, a curing agent is mixed with a solvent to form a fluid material that can then be mixed with a viscous silicone polymer. However, due to the need to ship the substantially solvent-free composition to the customer and subsequently apply it to the customer's device, the solvent that has been temporarily added is removed in the dry chamber. However, although the composition is substantially solvent-free, there may be traces of residual solvent that cannot be removed during the drying process. Removing this solvent by reducing shrinkage during the final curing process facilitates deposition of the compositions disclosed herein, minimizes shrinkage over time during device lifetime, and facilitates The thermal stability of the material.

Knowing the final application of the composition, the desired viscosity of the composition, and the particles to be included, it is possible to fine-tune the silicone polymer (starting compound, molecular weight, viscosity, etc.) so that when incorporated with particles and other components In the composition of the product, the desired final characteristics are achieved in terms of subsequent delivery to the customer. Due to the stability of the composition, it is possible to ship the composition at ambient temperature without any substantial change in molecular weight or viscosity, even a week or even a month after manufacture until end use by the customer.

example

The following silicone polymer examples are provided to illustrate the invention and are not intended to be restrictive.

The viscosity of the silicone polymer was measured by a Brookfield viscometer (spindle 14). The molecular weight of the polymer was measured by Agilent GPC.

Silicone polymer i: diphenylsilanediol (60 grams, 45 moles%), 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (55.67 grams, 36.7 moles %) and tetramethoxysilane (17.20 g, 18,3 mol%) filled a 500 ml round bottom flask with a stir bar and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.08 g of barium hydroxide monohydrate dissolved in 1 ml of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated off under vacuum. The silicone polymer has a viscosity of 1000 mPas and a Mw of 1100.

Silicone polymer ii: diphenylsilanediol (30 grams, 45 moles%), 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (28.1 grams, 37 moles %) and dimethyldimethoxysilane (6.67 g, 18 mole %) filled a 250 ml round bottom flask with a stir bar and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.035 grams of barium hydroxide monohydrate dissolved in 1 milliliter of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated under vacuum. The silicone polymer has a viscosity of 2750 mPas and a Mw of 896.

Silicone polymer iii: diphenylsilanediol (24.5 grams, 50 moles%), 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (18.64 grams, 33.4 moles %) and tetramethoxysilane (5.75 g, 16.7 mol%) filled with stirring 250ml round bottom flask with stirring rod and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.026 grams of barium hydroxide monohydrate dissolved in 1 mL of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated under vacuum. The silicone polymer has a viscosity of 7313 mPas and a Mw of 1328.

Silicone polymer iv: diphenylsilanediol (15 grams, 50 moles%), 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (13.29 grams, 38.9 moles %) and bis(trimethoxysilyl)ethane (4.17 g, 11.1 mol%) filled a 250 mL round bottom flask with a stir bar and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.0175 grams of barium hydroxide monohydrate dissolved in 1 mL of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated under vacuum. The silicone polymer has a viscosity of 1788 mPas and a Mw of 1590.

Silicone polymer v: Diphenylsilanediol (15 grams, 45 moles%), 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (13.29 grams, 35 moles %) and vinyltrimethoxysilane (4.57 g, 20 mol%) were filled in a 250 ml round bottom flask with a stir bar and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.018 grams of barium hydroxide monohydrate dissolved in 1 milliliter of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated off under vacuum. The silicone polymer has a viscosity of 1087 mPas and a Mw of 1004.

Silicone polymer vi: Diisopropylsilanediol (20.05 grams, 55.55 mol%), 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (20.0 grams, 33.33 mol%) mol%) and bis(trimethoxysilyl)ethane (7.3 g, 11.11 mol%) was filled in a 250 ml round bottom flask with a stir bar and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.025 grams of barium hydroxide monohydrate dissolved in 1 milliliter of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated off under vacuum. The silicone polymer has a viscosity of 150 mPas and a Mw of 781.

Silicone polymer vii: Diisobutylsilanediol (18.6 grams, 60 mol%) and 2-(3,4-epoxycyclohexyl) ethyl] trimethoxysilane (17.32 grams, 40 mol%) ear%) was filled with a 250 ml round bottom flask with a stir bar and reflux condenser. The flask was heated to 80°C under a nitrogen atmosphere and 0.019 grams of barium hydroxide monohydrate dissolved in 1 mL of methanol was added dropwise to the mixture of silanes. The silane mixture was stirred at 80° C. for 30 minutes during the reaction of the diphenylsilanediol with the alkoxysilane. After 30 minutes, the methanol formed was evaporated off under vacuum. The silicone polymer has a viscosity of 75 mPas and a Mw of 710.

Composition example

The following composition examples are provided to illustrate the invention and are not intended to be limiting.

Comparative example 1, silver-filled adhesive: silver flakes with an average size (D50) of 4 microns of siloxane polymer (18.3 grams, 18.3%) with epoxy groups as cross-linking functional groups were mixed using a high-shear mixer (81 grams, 81%) 3-Propyl methacrylate trimethoxysilane (0.5 grams, 0.5%) and Kings Industries K-PURE CXC-1612 Thermal acid generator (0.2%) was mixed together. The viscosity of the composition is 15000mPas.

Comparative example 2, alumina filled adhesive: use a three-roll mill to grind siloxane polymer (44.55 grams, 44.45%) with epoxy groups as cross-linking functional groups, and alumina with an average size (D50) of 0.9 microns (53 grams, 53%), 3-propyl methacrylate trimethoxysilane (1 grams, 1%), Yanjia Nox 1173 (1 grams, 1%) and Kings Industries K-PURE CXC-1612 heat Acid generator (0.45 g, 0.45%) was mixed together. The viscosity of the composition is 20000mPas.

Comparative Example 3, BN filled adhesive: use a three-roll mill to grind a siloxane polymer (60 grams, 60%) with an epoxy group as a crosslinking functional group, and boron nitride with an average size (D50) of 15 microns Flakes (35 g, 35%), Yanjia Nox 1173 (1.3 g, 1.3%), 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (3.4 g, 3.4%), and King’s Industrial K-PURE CXC-1612 Thermal Acid Generator (0.3 g, 0.3%) was mixed together. The viscosity of the composition is 25000mPas.

Comparative example 4, translucent material: a siloxane polymer (89 grams, 89%) having methacrylate as a functional group, fumed silica with an average size (D50) of 0.007 microns was made using a three-roll mill (5 grams, 5%), Yanjia Nox 1173 (2 grams, 2%) and Yanjiagu 917 photoinitiator (4 grams, 4%) were mixed together. The viscosity of the composition is 25000mPas.

Comparative Example 5, transparent material: diphenylsilanediol (20.0 grams, 92 millimoles), 9-phenanthrenyltrimethoxysilane (16.6 grams, 56 millimoles), 3-methacryloxy Propyltrimethoxysilane (9.2 g, 37 mmol) and BaO (25 mg) in methanol were placed in a 100 mL flask and refluxed for 1 h. Volatiles were evaporated under reduced pressure. A clear polymer resin (37 grams) was obtained.

Comparative Example 6, High Refractive Index Material: 8.6 grams of a polymer resin with a high refractive index prepared as described in Example X1 was dissolved in 5.7 grams of a ZrO nanoparticle solution in 1,2 _- propanediol monohydrate with a solids content of 50%. Blended in methyl ether acetate (PGMEA). 0.26 grams of photoinitiator (Darocur 1173 of BASF), 0.4 grams of oligomeric 3-methacryloxypropyltrimethoxysilane and 20 milligrams of surfactants (Bykchem (BYK-307 from BYK Chemie)) was added to the solution.

The obtained material was spin-coated on a 100 mm silicon wafer at 2000 rpm. The films were baked on a hot plate at 80°C for 5 minutes and UV cured at a dose of 3000 mJ/cm2. _The refractive index was tuned by changing the weight ratio of polymer resin to ZrO2 nanoparticles.

If the silicone composition as disclosed herein is disposed within the optical path of light emitted by the LED and is selected to be optically transmissive to visible (or UV) light, it may be based on the selected silicone particle material to choose the index of refraction. A refractive index of 1.25 to 2.0, such as 1.4 to 1.7 or other desired values (1.5 to 1.9, 1.25 to 1.45, etc.), can be provided, wherein the refractive index is measured at a wavelength of 632.8 nm. Higher refractive indices, for example higher than that of glass, such as 1.6 to 2.0, can be achieved by providing metal-containing monomers polymerized into the silicone polymer. As mentioned above, it is possible to obtain a [Si-O-Me-O]n (where Me is a metal) backbone. Especially metal containing monomers with metals such as titanium, tantalum, aluminum, zirconium, hafnium or selenium can help increase the refractive index. Such metal-containing monomers may be used instead of, or in addition to, the first, second or third compounds as mentioned above.

In addition, it is possible to increase the index of refraction based on particle selection (alternatively or in addition to incorporation of metals into silicone polymers as described above). Certain oxide particles, especially oxides such as titanium, tantalum, aluminum, zirconium, hafnium or selenium, can help increase the refractive index. Additionally, coupling agents that incorporate particles into the silicone polymer can be optionally modified to help increase the refractive index. As an example, mention may be made of a coupler of the formula: R ¹⁶ Ar) _i SiR ¹ _j

where i=1 or 2, and j=4-i, R ¹⁶ is a functional crosslinking group that undergoes crosslinking with the silicone polymer when heat or UV light is applied, Ar is an aryl group, and wherein R ¹ is Reactive groups such as hydroxyl, halo, alkoxy, carboxyl, amine or acyloxy.

Thus, the compound comprises a silicon atom bonded to one or two aryl groups with crosslinking substituents and the silicon atom is also bonded to two or three reactive groups, preferably alkoxy groups. The aryl group can be phenyl, naphthalene, phenanthrene, anthracene and the like. The R ₁₆ functional crosslinking group can be epoxy, acrylate, vinyl, allyl, acetylene, alcohol, amine, thiol, silanol, and the like. The coupling agent can also be selected to have metal atoms such as titanium, tantalum, aluminum, zirconium, hafnium, or selenium instead of silicon.

As can be seen in Figure 6, the refractive index of the cured silicone particle material as disclosed herein is plotted against the wavelength of light, and each plot has a different amount of particles that are part of the silicone material, with none Particles were added to the composition to 75% particle loading. As can be seen in Figure 6, a refractive index of 1.60 or greater in the visible spectrum can be achieved without particles, and in this example with particles. A refractive index of 1.70 or greater within the spectrum. As can be seen in Figure 7, the % transmission of the silicone material is plotted against the wavelength of light. As illustrated in this figure, different particle loadings from no particles to 75% are plotted, with a % transmittance of visible light greater than 90% (actually greater than 95%) within the visible spectrum. Therefore, even siloxane materials loaded with high % particles are extremely transparent and suitable for various optical applications, such as LED lights.

Given the disclosed methods and materials, stable compositions were formed. Part of the composition may be a siloxane polymer with a [-Si-O-Si-O]n repeating main chain, with alkyl or aryl groups on the main chain, and functional crosslinks on the main chain groups, and another part is particles mixed with siloxane material, wherein the average particle size of the particles is less than 100 microns, and the particles are any suitable particles, such as metal, semi-metal, semiconductor or ceramic particles. Compositions shipped to customers may have a molecular weight of 300 g/mole to 10,000 g/mole and a viscosity of 1000 MPa-s to 75000 MPa-s at a 5 rpm viscometer.

Viscous (or liquid) silicone polymers are substantially free of -OH groups, thus providing extended shelf life and allowing storage or shipping at ambient temperature if necessary. Preferably, the siloxane material has no -OH peaks detectable from FTIR analysis. Increased stability of the formed silicone material to allow storage prior to use with minimal increase in viscosity (crosslinking) during storage, such as less than 25% over a period of 2 weeks at room temperature, preferably over 2 weeks The period is less than 15%, and more preferably less than 10%. In addition, storage, shipping, and subsequent application by the customer can all be carried out in the absence of solvent (except for possible trace residues remaining after drying to remove solvent), avoiding solvent entrapment in layers subsequently formed in the final product , Shrinkage during polymerization, quality loss over time during device use, etc. No substantial crosslinking occurs during shipping and storage without the application of heat or UV light, preferably greater than 100°C.

When the composition was deposited and polymerized (for example by applying heat or UV light), little shrinkage or loss of mass was observed. In Figure 8, the x-axis is time in minutes, the left y-axis is the mass of the layer in terms of % of starting mass, and the right y-axis is temperature in degrees Celsius. As can be seen in Figure 8, the silicone particle mixture as disclosed herein was rapidly heated to 150°C and then held at 150°C for approximately 30 minutes. In this example, the silicone particles have a Si—O backbone with phenyl and epoxy groups, and the particles are silver particles. After thermal curing over this period, the mass loss was less than 1%. Desirably, mass loss is typically less than 4%, and generally less than 2%. In many cases, however, the difference in mass of the silicone particle composition between before and after curing is less than 1%. Curing temperatures are generally below 175°C, although higher curing temperatures are possible. Typically, the curing temperature will be 160°C or less, more typically 150°C or less. However, lower curing temperatures are possible, such as 125°C or lower.

As can be seen in Figure 9, no matter whether the composition disclosed above is used as an adhesive, a thermally conductive layer, a sealant, a patterned conductive layer, a patterned dielectric layer, a transparent layer, a light reflective layer, etc., once the composition is deposited and Polymerized and optionally hardened, the silicone particle layer or mass is extremely thermally stable. For example, after the in-situ material is heated to 600°C at a rate of 10°C per minute after hardening by thermal polymerization or UV polymerization, less than 4.0% is observed at both 200°C and 300°C, preferably Less than 2.0%, such as less than 1.0% mass loss (usually less than 0.5% mass loss is observed at 200°C, or as in the example of Figure 9, less than 0.2% mass loss is observed at 200°C). At 300° C., a mass loss of less than 1%, or more specifically less than 0.6%, was observed in the example of FIG. 9 . Similar results can be observed by heating the polymeric material at only 200°C, or 300°C for 1 hour. Less than 1% mass loss results are possible by heating the polymerized deposition material at or above 375°C for at least 1 hour. As can be seen in Figure 9, even in A mass loss of 5% or less was observed at temperatures greater than 500°C. Such thermally stable materials are desirable and in particular can be deposited at low temperatures (e.g. below 175°C, preferably below 150°C, or below 130°C for 30 minutes cure/bake time), or can be deposited by A thermally stable material as disclosed herein polymerized by UV light.

There are many alternatives to LED lights with silicone materials as disclosed herein. For example, in Figure 10a, a die 51 may be bonded to an encapsulation substrate 50 and covered with a cover substrate 52, with or without particles or phosphors or other wavelength shifting elements, depending on the desired use of the lamp. Silicone encapsulant 53 for components is filled. Alternatively, as can be seen in Figure 10b, a conformal layer 55, which is a silicone material (with or without added particles as desired, and with or without phosphor as desired), may be applied. The area between conformal layer 55 and cover substrate 52 may also be filled with a silicone encapsulant (again with or without added particles). Alternatively, as can be seen in Figure 10c, only the die 51 is covered with a silicone material with optional particles and phosphor. In this embodiment, typically, the silicone material is added at the wafer level prior to die singulation. Alternatively, as can be seen in Figure 10d, a conformal layer 55 may be provided, such as a layer formed on the cover substrate 52 (or this may alternatively be a phosphor embedded within the cover substrate 52). As with other examples, the silicone may or may not have particles, but in such examples where the light from the LED passes through it, the encapsulant is preferably optically transmissive. In FIGS. 10 a - 10 d , the die is in each case the substrate material mentioned with respect to the previous examples, and may, if necessary, be attached to the encapsulation substrate via a silicone particle material as disclosed herein.

As can be seen from the above disclosure, the silicone particle composition as disclosed above can be used as an adhesive, a protective layer, part of a wavelength shifting layer, or a visible light directing lens (among other embodiments). If used as an adhesive, the material is preferably not in the visible spectrum Is optically absorptive, and preferably transmits or reflects at least 75%, but preferably greater than 80%, or greater than 85% or even higher, such as greater than 90% or 95%, of visible light incident thereon. As a wavelength shifting layer, phosphors, luminophores, scintillators or other chemical elements are incorporated and absorb light at one wavelength and emit light at a second, different wavelength. Such wavelength shifting elements may be part of a layer of the first silicone composition proximate to a second lens comprising a silicone composition in the absence of any wavelength shifting elements. Alternatively, the lens may include both a silicone composition and a wavelength shifting element such as a phosphor. It is also possible that the siloxane particle composition exists as a conductive material, such as for flip-chip die attach bumps, or for wire bonds connecting substrates. Conductive regions and patterned regions may also comprise silicone materials according to the invention.

The foregoing illustrates example embodiments and is not to be construed as limiting. Although a few example embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. Therefore, it is to be understood that the foregoing describes various example embodiments and should not be construed as limited to the particular embodiments disclosed and that modifications of the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims.

Industrial applicability

The disclosed compositions can be used, for example, as adhesives, thermally conductive layers, sealants, patterned conductive layers, patterned dielectric layers, transparent layers, light reflective layers in LED lamps and lamps. The LED light of the present invention has many uses, such as outdoor signage; LED pixel arrays for flat panel displays; LED backlights for LCD displays; indoor screens for public events and public transportation; outdoor screens, such as sports or other public events large screens; indoor and outdoor advertising screens; consumer electronics or for use in said articles LED lights on any equipment, device or mechanism; infrared LEDs, such as in remote controls; LEDs in traffic signals and road lighting; automobile taillights, headlights and interior lighting; flashlights; greenhouse lighting for indoor growing agricultural products; And in general, as an alternative (among other implementations) when using incandescent bulbs or fluorescent lighting. LED will dominate the lighting field in the foreseeable future and play an important role in energy saving, environmental protection, and improvement of quality of life.

reference list

patent documents

US 2009221783

US2012123054

WO20100267

US 2011171447

JP 2004225005

10a, 10b: electrodes

12: n-doped gallium nitride region

13: p-doped gallium nitride region

14: Sapphire substrate

17: Adhesive layer

19: Support substrate or packaging substrate

Claims (14)

An LED lamp comprising: a die substrate, wherein a semiconductor material is formed on the die substrate; electrodes for applying a bias voltage across the semiconductor material to cause light to be emitted from the semiconductor material; and an adhesive, Bonding the die substrate to the support substrate, wherein the adhesive has a thermal conductivity greater than 0.1 W/m. Polymerized siloxane polymers of Kelvin (W/(m.K)), and wherein said siloxane polymer has silicon and oxygen in and bonded to said polymer backbone aryl or alkyl, and wherein the adhesive further comprises particles; wherein the adhesive does not absorb light and transmits or reflects at least 80% of visible light incident thereon, and the siloxane polymer does not contain- OH groups, wherein the siloxane polymer is prepared by performing a polymerization reaction between a first compound and a second compound, wherein the particles are selected from the group consisting of gold, silver, copper, platinum, palladium, indium, iron, Nickel, aluminum, carbon, cobalt, strontium, zinc, molybdenum, titanium, tungsten, silver-coated copper, silver-coated aluminum, bismuth, tin, bismuth-tin alloys, silver-coated fibers, or alloys or combinations thereof, wherein the particles comprise average A first set of particles having a particle size greater than 500 nm and a second set of particles having an average particle size less than 100 nm, wherein the first compound has the formula: SiR ¹ _a R ² _4-a where a is 1 to 3, R ¹ is a reactive group, and R ² is an alkyl or aryl group, wherein the second compound has the following chemical formula: SiR ³ _b R ⁴ _c R ⁵ _4-(b+c) wherein R ³ is a crosslinking functional group, R ⁴ is a reactive group, and R ⁵ is an alkyl or aryl group, and wherein b=1 to 2, and c=1 to (4-b). The LED lamp as described in claim 1, wherein the siloxane polymer includes aryl groups bonded to silicon in the polymer main chain. The LED lamp described in claim 1 of the patent application, wherein the adhesive is a light reflective layer, and the light reflective layer reflects at least 80% of the light incident on it at an angle of 90 degrees. The LED lamp as described in claim 1 of the patent application, wherein the adhesive is a light reflective layer, and the light reflective layer reflects at least 90% of the light incident on it at an angle of 90 degrees. The LED lamp as described in claim 1 of the patent application, wherein the siloxane polymer includes an aryl group. The LED lamp described in claim 1 of the patent application, wherein the adhesive is thermally stable, and when heated to at least 200°C, the mass loss of the adhesive is less than 1%. In the LED lamp described in claim 1 of the patent application, the refractive index of the adhesive is 1.4 to 1.6. A method of manufacturing an LED lamp, comprising: forming a light-emitting diode by providing a semiconductor material on a first substrate and doping the semiconductor material; providing a supporting substrate; providing an adhesive composition, the adhesive composition comprising A siloxane polymer having silicon and oxygen in the polymer backbone, an aryl or an alkyl group bonded to the polymer backbone, and a functional cross bonded to the polymer backbone Linked groups, the thermal conductivity of the siloxane polymer is greater than 0.1 W/m. Kelvin (W/(m.K)), the adhesive composition further includes particles, catalysts; depositing the adhesive composition to bond the first substrate to the support substrate; and applying temperature and /or light to activate the functional crosslinking group of the silicone polymer to further polymerize the silicone polymer and harden the silicone polymer, and at the same time connect the first substrate and the support Substrates are joined together, wherein the polymerized and hardened silicone polymer has at least 96% mass after polymerization compared to before polymerization, and wherein the silicone polymer does not absorb more than 25% of the incident light on On visible light, the siloxane polymer does not contain -OH groups, wherein the siloxane polymer is prepared by performing a polymerization reaction between a first compound and a second compound, wherein the particles are selected from From gold, silver, copper, platinum, palladium, indium, iron, nickel, aluminum, carbon, cobalt, strontium, zinc, molybdenum, titanium, tungsten, silver-plated copper, silver-plated aluminum, bismuth, tin, bismuth-tin alloy, Silver-coated fibers or alloys or combinations thereof, wherein the particles comprise a first set of particles having an average particle size greater than 500 nm and a second set of particles having an average particle size less than 100 nm, wherein the first compound has the formula: SiR ¹ _a R ² _4-a wherein a is 1 to 3, R ¹ is a reactive group, and R ² is an alkyl or aryl group, wherein the second compound has the following chemical formula: SiR ³ _b R ⁴ _c R ⁵ _{4 -(b+c)} wherein R ³ is a crosslinking functional group, R ⁴ is a reactive group, and R ⁵ is an alkyl or aryl group, and wherein b=1 to 2, and c=1 to (4-b ). The manufacturing method of the LED lamp as described in item 8 of the scope of the patent application, wherein the resistivity of the polymerized and hardened siloxane polymer is less than 1×10 ^-3 Ω. m. The method for manufacturing an LED lamp as described in claim 8, wherein the polymerized and hardened siloxane polymer has a mass of at least 98% after polymerization compared to before polymerization. A method for sealing an LED device, comprising: forming a light-emitting diode by providing a semiconductor material on a first substrate and doping the semiconductor material; providing a sealant composition, the sealant composition comprising siloxane polymer The siloxane polymer has silicon and oxygen in the polymer main chain, an aryl group or an alkyl group combined with the polymer main chain, and a functional crosslinking group combined with the polymer main chain, The thermal conductivity of the siloxane polymer is greater than 0.1 W/m. Kelvin (W/(m.K)), the encapsulant composition further includes particles, catalysts; depositing the encapsulant composition to seal the light-emitting diodes; and applying temperature and/or light to activate The functional crosslinking group of the siloxane polymer to further polymerize the siloxane polymer and harden the siloxane polymer, wherein the siloxane polymer polymerized and hardened after polymerization having a mass of at least 96% compared to before polymerization, and wherein the silicone polymer does not absorb more than 25% of visible light incident thereon, the silicone polymer does not contain -OH groups, wherein the The siloxane polymer is prepared by polymerizing between a first compound and a second compound, wherein the particles are selected from the group consisting of gold, silver, copper, platinum, palladium, indium, iron, nickel, aluminum, carbon, Cobalt, strontium, zinc, molybdenum, titanium, tungsten, silver-coated copper, silver-coated aluminum, bismuth, tin, bismuth-tin alloys, silver-coated fibers, or alloys or combinations thereof, wherein the particles include particles having an average particle size greater than 500 nm A first set of particles and a second set of particles having an average particle size of less than 100 nanometers, wherein the first compound has the following chemical formula: SiR ¹ _a R ² _4-a where a is 1 to 3, R ¹ is a reactive group, And R ² is an alkyl or aryl group, wherein the second compound has the following chemical formula: SiR ³ _b R ⁴ _c R ⁵ _4-(b+c) wherein R ³ is a crosslinking functional group, R ⁴ is a reactive group group, and R ⁵ is alkyl or aryl, and wherein b=1 to 2, and c=1 to (4-b). The sealing method of an LED device as described in claim 11, wherein the sealant composition includes a photoinitiator, and ultraviolet light is applied to cure and harden the siloxane polymer. The method for sealing LED devices as described in claim 11, wherein the sealant composition includes a thermal curing agent, and the sealant composition is cured at a temperature lower than 150°C. The sealing method of an LED device as described in claim 13 of the patent application, wherein the curing temperature of the sealant composition is lower than 100°C.

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