KR20220073969A - Solder paste composition for power semiconductor package - Google Patents

Abstract

The present invention discloses a solder paste composition suitable for a pressureless sintering type because it has excellent thermal conductivity, heat resistance, and heat dissipation characteristics, and can dramatically shorten process time and temperature.
The solder paste composition according to the present invention includes a metal powder; an epoxy resin containing a nitrogen atom and a lone pair of electrons; hardener; metal complexes; catalyst; and additives.

Description

Paste composition for soldering of a power semiconductor package {SOLDER PASTE COMPOSITION FOR POWER SEMICONDUCTOR PACKAGE}

The present invention relates to a solder paste composition for a power semiconductor package that can maximize the physical properties of a SiC semiconductor chip, including a glycidyl amine-based epoxy resin and a metal complex.

A power semiconductor is a device that converts, transforms, stabilizes, distributes and controls power, and improves energy efficiency and stably controls voltage changes in the power delivery and control process. It provides stability and reliability.

For power semiconductors, Si-based semiconductor devices are mainly used.

Recently, as the demand for high-output and high-efficiency power semiconductors increases as the eco-friendly automobile and renewable energy markets increase, the need for WBG (wide band gap) compound semiconductors based on silicon carbide (SiC), gallium nitride (GaN), etc. This is a strengthening trend.

Among WBG (wide band gap) compounds, SiC has a very excellent dielectric breakdown field strength of about 10 times that of Si and a band gap of about 3 times that of Si.

SiC can control the P-type and N-type required for device manufacturing in a wide range, and its thermal conductivity is 4.9 W/mK compared to 1.5 W/mK of Si, which is about three times better.

In addition, since SiC has a melting point of 300°C or higher, it operates stably even at high operating temperatures.

In addition, according to the research results, when the conventional Si IGBT (Insulated Gate Bipolar Transistor) power semiconductor is changed to a SiC power semiconductor, the volume is reduced to about 50% or less and the energy efficiency is increased by about 85% or more.

Accordingly, it is expected that SiC power semiconductors will be essentially used instead of conventional Si IGBT power semiconductors for high-voltage, high-current, high-power applications.

The power semiconductor may be used alone, but is usually applied to a product in the form of a module including the power semiconductor.

In the power semiconductor package or module, a power semiconductor chip bonded by solder is positioned on DBC (Direct Bonding Copper) in which copper is directly bonded to upper and lower portions of a ceramic substrate. A metal base plate is bonded to the lower portion of the DBC through solder.

Since the power semiconductor package in which SiC is applied to the power semiconductor chip has a significantly higher operating temperature than the conventional power semiconductor package to which Si is applied, a technique for increasing thermal conductivity in the package and improving resistance to thermal stress is required.

In addition, a technology capable of maximizing the excellent physical properties of SiC in a power semiconductor package is required.

In this regard, the bonding material of the power semiconductor chip should basically meet the physical properties of high adhesion, high heat dissipation, resistance to repeated thermal shock, and not re-melting even at high operating temperature, and commercially fairness and price competitiveness. should have

As a bonding material for the power semiconductor chip, a solder paste composition such as Ag-Pb or Sn-Ag-Cu (SAC) is mainly used, but it has several problems when applied to a power semiconductor package to which SiC is applied.

Because solder paste compositions such as Ag-Pb and Sn-Ag-Cu (SAC) are re-melted at about 180° C. and defects such as cracks occur, they are suitable for use in high-voltage, high-current, high-temperature power semiconductors. don't

In addition, lead lead solder materials or SAC materials cause interfacial delamination, stress concentration, and permanent creep deformation due to thermal fatigue in the thin film layer as the power on/off is repeated.

In addition, Cu/Sn/Cu transient liquid phase bonding (TLP) is a multilayer interface, and cracks frequently occur, causing reliability problems.

On the other hand, as a process technology of the solder paste composition, there are soldering, eutectic bonding, pressure sintering, pressureless sintering, and the like.

Among them, metal sintering provides a film in a solid state, exhibits high adhesive strength, high thermal conductivity of 150 ~ 300W/mK, and high melting point, and is known as the best alternative.

The pressure sintering method has the effect of reducing the time and process temperature required for bonding the power semiconductor chip by applying a pressure of about 30 MPa to the semiconductor chip and expanding the contact area of the metal powder.

However, the pressurized sintering method causes damage to the semiconductor chip due to pressurization, is difficult to see as a mass-produceable technology, and is limited to very expensive power modules.

Metal sintering using a pressure free sintering method is the most ideal method, but sintering takes about 200 minutes or more and has a limitation in that mass productivity is insufficient due to a high process temperature.

Among the pressureless sintering methods, the method using copper has disadvantages in that an inert gas atmosphere must be applied to the bonding process and an alternative is difficult due to oxidation problems during use.

Therefore, there is a demand for a paste composition technology for a non-pressurized sintering type solder that can replace the conventionally used solder paste composition, has high thermal conductivity and heat resistance, and can be applied to a SiC-based power semiconductor package.

An object of the present invention is to provide a paste composition for soldering a power semiconductor package having excellent thermal conductivity, heat resistance, and heat dissipation characteristics.

It is also an object of the present invention to provide a paste composition for non-pressurized sintering type solder, which can dramatically reduce process time and temperature.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the appended claims.

The solder paste composition according to the present invention includes a metal powder; an epoxy resin containing a nitrogen atom and a lone pair of electrons; hardener; metal complexes; catalyst; and additives.

The solder paste composition according to the present invention has excellent thermal conductivity, heat resistance, and heat dissipation characteristics.

In addition, the solder paste composition according to the present invention can significantly shorten the process time and process temperature, so it is suitable for the pressureless sintering type.

In addition, the solder paste composition according to the present invention does not re-melt even at a high temperature of 300° C. or higher after completion of heat treatment (reflow) despite the low processing temperature, so there is an advantage in that the operating temperature of the SiC or GaN semiconductor package can be increased.

In addition, the solder paste composition according to the present invention has a specific resistance and thermal conductivity close to that of pure silver after heat treatment, and thus has the advantage of maintaining package performance with little change in package resistance even after a thermal cycle test.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 is an FT-IR spectrum of a silver complex according to the present invention.
2 is an SEM image of the surface of the solder paste composition having different catalyst contents according to the present invention after curing at 165° C./10 min and 220° C./20 min.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

In the following, that an arbitrary component is disposed on the "upper (or lower)" of a component or "upper (or below)" of a component means that any component is disposed in contact with the upper surface (or lower surface) of the component. Furthermore, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

In addition, when it is described that a component is “connected”, “coupled” or “connected” to another component, the components may be directly connected or connected to each other, but other components are “interposed” between each component. It should be understood that “or, each component may be “connected,” “coupled,” or “connected,” through another component.

Hereinafter, a paste composition for a solder of a power semiconductor package according to some embodiments of the present invention will be described.

The solder paste composition of the power semiconductor package of the present invention can replace the conventional solder paste composition such as SAC, and improves the long process time and high process temperature, which are the disadvantages of the conventional pressureless sintering paste composition, and provides excellent Provides thermal conductivity and heat resistance.

The solder paste composition of the present invention includes a metal powder, an epoxy resin containing a nitrogen atom and a lone pair (lewis base), a curing agent, a metal complex, a catalyst, and an additive.

The metal powder constituting the solder paste composition provides high thermal conductivity, and preferably contains silver (Ag).

The metal powder is a base component of the solder paste composition, and accounts for 80 wt% or more.

In the conventional semiconductor package field to which the solder paste composition of the present invention belongs, mainly epoxy-based resins have been used. In particular, bisphenol A-based epoxy or a mixture of bisphenol A-based epoxy and bisphenol F-based epoxy was mainly used.

However, bisphenol A-based epoxy has a large free volume and has a high coefficient of thermal expansion of 55 to 75 ppm/°C, and there is a limit in lowering the thermal expansion coefficient of bisphenol A-based epoxy even when highly impregnated with thermally conductive powder.

In addition, bisphenol A-based epoxy has a higher viscosity than glycidyl amine-based epoxy, so there is a limitation in adding a large amount of thermally conductive powder.

In particular, in the power semiconductor package in the present invention, the coefficient of thermal expansion is one of very important requirements for reliability.

For lifetime and reliability evaluation, the power semiconductor package is typically exposed to a thermal cycle of high temperature and low temperature for a period of time or recovery.

After the thermal cycle, the requirement that no cracks occur in the power semiconductor package must be met.

If the thermal expansion coefficient of any component among the power semiconductor package components has a large difference from the thermal expansion coefficient of other components, or if the thermal expansion coefficient of any component is very large, the component having a large thermal expansion coefficient or a component having a large difference in the thermal expansion coefficient is It can cause catastrophic problems such as cracking by thermal cycling.

For the above reasons, it is preferable to include a glycidyl amine-based epoxy resin in the solder paste composition of the power semiconductor package according to an embodiment of the present invention.

A glycidyl amine-based epoxy resin is an epoxy resin that contains one or more nitrogen atoms and contains a lone pair of electrons.

In the epoxy resin, in addition to nitrogen, oxygen or the like also has a lone pair of electrons.

The epoxy resin provides low modulus properties to relieve mechanical stress applied to the power semiconductor package by thermal shock. Accordingly, the epoxy resin ensures sufficient durability and reliability even at a high operating temperature of the power semiconductor chip.

Glycidyl amine epoxy resin contains at least one of Triglycidyl p-aminophenol (TGPAP), Tetraglycidyl diaminodiphenylmethane (TGDDM), Triglycidyl m-aminophenol (TGMAP), Tetraglycidyl diaminodiphenylsulfone (TGDDS), Diglycidyl Aniline and Diglycidyl-o-Toluidine can do.

The epoxy resin constituting the solder paste composition may be included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the metal powder.

When the content of the epoxy resin is less than 1 part by weight, it may be insufficient to relieve the mechanical stress applied to the power semiconductor package, and it may be insufficient to ensure durability and reliability of the power semiconductor package.

On the other hand, when the content of the epoxy resin exceeds 5 parts by weight, the weight of the solder layer increases as the content of the resin increases, and there is a disadvantage in that only the manufacturing cost increases without improving durability and reliability.

The curing agent preferably includes an acid anhydride curing agent.

The acid anhydride-based curing agent is, for example, nadic maleic anhydride, dodecyl succinic anhydride, maleic anhydride, succinic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride ( HHPA), tetrahydrophthalic anhydride, pyromellitic dianhydride, cyclohexanedicarbonyl anhydride, methyl tetrahydrophthalic anhydride (MeTHPA), methyl hexahydrophthalic anhydride (MeHHPA), nadic methyl anhydride (NMA), hydrolyzed methyl nadic anhydride, phthalic anhydride, nadic anhydride, and the like.

The mixing ratio of the epoxy resin and the curing agent constituting the solder paste composition may be 1:1 to 1:2 by weight.

When the mixing ratio of the epoxy resin and the curing agent is out of the range of the weight ratio of 1:1 to 1:2, the exothermic reaction due to the curing reaction does not occur properly, so curing at low temperature and welding between the metal powder are not sufficiently performed. it may not be

On the other hand, in the solder paste composition developed in the present invention, curing and welding between silver powder are harmoniously performed at a low temperature of 250° C. or less by exothermic reaction heat caused by the curing reaction of the epoxy resin and the curing agent and heat applied from the outside. Accordingly, it is possible to form a welding phase of high curing density and continuous silver powder.

In addition, the process time and temperature can be dramatically shortened, so there is an advantage suitable for the pressureless sintering type.

In the process of sintering, the metalo-organic compound becomes binder burnout as the organic material is blown away, thereby forming a welding in the space between the metals and forming a network.

That is, the metal complex induces low-temperature sintering and welding at the metal powder interface, and forms an intermetallic connection made of two or more kinds of metals, thereby providing a low heat resistance path for heat transfer.

In the FT-IR spectrum, the metal complex has a vibrational peak of the metal-oxygen group at a wavelength of 881 to 429cm ^-1 in the FT-IR spectrum, and a -C=O asymmetric stretching vibrational peak exists at a wavelength of 1505 to 1510cm ^-1 .

The bond of the metal complex absorbs the energy when it receives infrared energy and vibrates. At this time, depending on the type of atom or the type of bond, a unique vibration is generated when it receives infrared rays, and through this, it is possible to analyze the atoms and bonds of a chemical substance.

When the bond vibrates, a change in the magnitude of the dipole moment appears, and the efficiency of absorbing infrared radiation depends on the strength of the dipole moment.

The carbonyl group (C=O) has a greater dipole moment than C=C because of its greater electronegativity. Accordingly, the carbonyl group absorbs infrared rays better and shows a strong peak.

The FT-IR spectrum shows two types of vibration, stretching vibration and bending vibration.

Stretching vibration is a method in which the bond length between atoms is lengthened and shortened, and bending vibration is a method in which the position of atoms with respect to the original bond axis changes, that is, the bond angle between atoms is changed.

Even in stretching vibration, when atoms move in the same phase, they are symmetrical, and when they move in different phases, they are asymmetric.

These vibration peaks appear greatest when stretching vibrations.

In addition, the carbonyl group (C=O) does not have a bond angle between atoms, so only stretching vibrations occur.

1 is an FT-IR spectrum of a silver complex according to the present invention.

As shown in FIG. 1, the FT-IR spectrum contains a -C=O asymmetric stretching vibrational peak at about 1508cm ^-1 and an Ag complex having a metal-O group vibrational peak at a wavelength between about 881 and 429cm ^-1 . It is preferable to do

The metal complex compound constituting the solder paste composition may be included in an amount of 0.1 to 1.1 parts by weight based on 100 parts by weight of the epoxy resin.

When the metal complex compound satisfies 0.1 to 1.1 parts by weight, necking and welding can occur even at a low temperature at the interface between the metal particles. Here, the necking refers to a phenomenon that expands to both sides when pulled at a softening temperature.

On the other hand, when the metal complex compound exceeds 1.1 parts by weight, there is a problem in that thermal conductivity and adhesive strength are remarkably reduced due to a decrease in dispersibility and an increase in viscosity due to an excess of the metal complex compound.

The catalyst functions to accelerate the curing reaction of the epoxy resin containing a nitrogen atom and a lone pair of electrons and an acid anhydride-based curing agent.

The catalyst preferably includes an imidazole-based catalyst.

The catalyst constituting the solder paste composition is preferably included in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the epoxy resin.

When the catalyst satisfies 0.01 to 2.0 parts by weight, the curing reaction time is not delayed and further activation of the curing agent can be induced.

Through activation of the acid anhydride curing agent by the imidazole catalyst, an esterification reaction between the epoxy resin and the curing agent is primarily induced.

And, curing occurs competitively through esterification and etherification (ROR') reaction by the hydroxyl group of the epoxy resin and reaction by homopolymerization of the remaining epoxy.

Table 1 below shows the results of differential scanning calorimetry (DSC) analysis of the solder paste composition for each catalyst content measured at a rate of 10° C./min.

[Table 1]

Referring to Table 1, as the content of the imidazole catalyst increases, it can be seen that the esterification peak occurs at a gradually lower temperature, and the etherification peak occurs at an almost constant temperature regardless of the content.

In addition, the total heat generated during the curing reaction tends to decrease as the content of the catalyst increases. This means that the conversion rate decreases as the catalyst content increases.

Since the paste composition for solder in the present invention uses the heat of reaction and external heat of the epoxy resin and the curing agent, 2 parts by weight or less is preferable in view of the fact that the greater the heat of reaction is, the better. More preferably, 1.6 parts by weight or less is good.

These results can be confirmed through the SEM image of the surface after curing the solder paste composition with different catalyst content in FIG. 2 at 165° C./10 min and 220° C./20 min.

Referring to FIG. 2 , a network of continuous silver particles was formed when the amount was 2 parts by weight or less. More preferably, it can be seen that the welding between the silver particles occurs best at 1.7 parts by weight.

In addition, in Fig. 2, 1.1 parts by weight have a specific resistance of 3.87 x 10 ^-6 Ωcm, thermal conductivity 272W/mK, 1.7 parts by weight have a specific resistance of 4.21 x 10 ^-6 Ωcm, thermal conductivity 220W/mK, and 2.2 parts by weight have a specific resistance of 4.8 x 10 ^-6 Ωcm, thermal conductivity 187 W/mK, 3.1 parts by weight shows a specific resistance of 7.5 x 10 ^-6 Ωcm and a thermal conductivity of 71 W/mK, it can be seen that the content of the catalyst is an important factor.

The imidazole-based catalyst is, for example, 2-methylimidazole (2-methylimidazole, 2MZ), 2-undecylimidazole (2-undecylimidazole, C11-Z), 2-heptadecylimidazole (2 -heptadecylimidazole, C17Z), 1,2-dimethylimidazole (1,2-dimethylimidazole, 1.2DMZ), 2-ethyl-4-methylimidazole (2-ethyl-4-methylimidazole, 2E4MZ), 2- Phenylimidazole (2-phenylimidazole, 2PZ), 2-phenyl-4-methylimidazole (2-phenyl-4-methylimidazole, 2P4MZ), 1-benzyl-2-methylimidazole (1-benzyl-2 -methylimidazole, 1B2MZ), 1-benzyl-2-phenylimidazole (1-benzyl-2-phenylimidazole, 1B2PZ), 1-cyanoethyl-2-methylimidazole (1-cyanoethyl-2-methylimidazole, 2MZ) -CN), 1-cyanoethyl-2-ethyl-4-methylimidazole (1-cyanoethyl-2-ethyl-4-methylimidazole, 2E4MZ-CN), 1-cyanoethyl-2-undecylimida Sol (1-cyanoethyl-2-undecylimidazole, C11Z-CN), 1-cyanoethyl-2-phenylimidazolium trimellitate (1-cyanoethyl-2-phenylimidazolium trimellitate, 2PZCNS-PW), 2,4-di Amino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine (2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s- triazine, 2MZ-A), 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine (2,4-diamino-6-[2') -undecylimidazolyl-(1')]-ethyl-s-triazine, C11Z-A), 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl -s-triazine (2,4-diamino-6-[2'-ethyl-4'-methylimidazo lyl-(1')]-ethyl-s-triazine, 2E4MZ-A), 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-striazine isocycline Anuric acid adduct (2,4-diamino-6-[2'-metthylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2MA-OK), 2-phenyl-4,5-dihydride Roxymethylimidazole (2-phenyl-4,5-dihydroxymethylimidazole, 2PHZ-PW), 2-phenyl-4-methyl-5-hydroxymethylimidazole (2-phenyl-4-methyl-5-hydroxymethylimidazole, 2P4MHZ-PW).

The solder paste composition of the present invention preferably includes an additive in order to improve durability against thermal shock by reducing modulus.

The additive is an additive for reducing modulus, and provides an effect of alleviating thermal shock.

The modulus reducing additive may include at least one of ester, butadiene, acrylate, and glycol-based epoxy.

In addition, the modulus reducing additive may be added in the form of a core-shell powder by using at least one resin material among ester, butadiene, acrylate, and glycol-based epoxy.

For example, the modulus reducing additive may be added in the form of a powder including a rubber butadiene core and an acrylate shell.

The additive constituting the solder paste composition is preferably included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the metal powder.

When the content of the additive satisfies 0.5 to 5 parts by weight, it is possible to secure an appropriate modulus, thereby obtaining an effect of alleviating thermal and mechanical stress caused by a sudden temperature change.

When the FT-IR spectrum was analyzed before curing using the solder paste composition prepared by the present invention, characteristic peaks of the -C=O acid anhydride curing agent were observed at 1856.34cm ^-1 and 1777.82cm ^-1 .

-CO oxirane peaks were observed at 983.74 cm ^-1 , 912.55 cm ^-1 , and 897.87 cm ^-1 , and -COC oxirane characteristic peaks were observed at 808.07 cm ^-1 .

At 1721.02 cm ^-1 , a -C=O ester peak related to the dispersant was observed.

At 1634.48 cm ^-1 , a -C=NH amine peak related to the catalyst was observed.

And aromatic rings were observed at 1513,77 cm ^-1 , 1464.76 cm ^-1 , and 1406 cm ^-1 .

As described above, a detailed example of the solder paste composition of the power semiconductor package will be described as follows.

1. Preparation of paste composition for solder

With respect to 100 parts by weight of the silver powder, an epoxy resin, a curing agent, a dispersant, a core-shell powder (CSR), and other additives (parts by weight) are weighed, and then a homogeneous mixture is prepared using a rotational mixer or a rotational mixer.

Thereafter, silver powder is added by weighing and stirred for about 1 hour using a planetary mixer. And finally, a catalyst is added, and the paste composition for solder is prepared by stirring until completely dispersed using a 3-roll mill connected to a chiller. All compositions of Examples and Comparative Examples were prepared using the method described above.

2. Methods for evaluating physical properties and their results

1) Specific resistance: After coating the prepared composition with a tool and curing at 165° C. for 10 minutes and at 220° C. for 20 minutes, the sheet resistance was measured with a 4-terminal probe using Loresta-GX, and the thickness of the sample was measured. .

2) Thermal conductivity: The prepared composition was prepared by casting to a diameter of 12.5 mm and a thickness of 2 mm, and coated with graphite to complete a sample for measuring thermal conductivity.

The thermal diffusivity was measured using LFA (laser flash analysis) equipment, and λ (thermal conductivity) = a (thermal diffusivity) × C _p (specific heat) × ρ (density) was calculated by the formula.

3) Chip adhesion strength: A sample for measurement was prepared by dispensing the composition prepared on a copper substrate, placing a 1.4mm x 1.4mm SiC chip on it, and heat-treating it.

Shear strength was measured at room temperature using a die shear tester equipment.

4) Storage modulus: A sample for DMA measurement was prepared by casting molding using the prepared composition. The elastic modulus of the DAP bonding material was measured at room temperature and 200 °C using DMA (Dynamic Mechanical Analyzer) equipment. At a temperature increase rate of 5 °C/min, a static force of 110 mN and a dynamic force of 100 mN were applied to the sample at a cycle of 1 Hz. was added and measured.

5) Thermal cycle test: Using a package sample with a 2mm x 2mm SiC chip attached, the sample was measured under Test condition G according to JEDEC.

After 1000 cycles, samples were collected and X-ray CT, package resistance change rate, and adhesive strength were evaluated to evaluate whether or not they passed.

[Table 2]

[Table 3]

As shown in Table 3, when containing 1.1 parts by weight or less of an epoxy resin containing at least one nitrogen atom and having a lone pair, lewis base, and 1.1 parts by weight or less of a complex compound having a vibrational peak of the metal-O group, all 170 It showed thermal conductivity of W/mK or higher and adhesive strength of 1.6kgf/mm ² or higher.

And it can be seen that the thermal cycle (thermal cycle) test passed.

[Table 4]

[Table 5]

From Table 5, it was confirmed that when the silver content was 100 parts by weight and the silver complex compound was 1.1 parts by weight or less, they all had high thermal conductivity of 200 W/mK or more, high adhesive strength, and passed the thermal cycle test.

On the other hand, it was confirmed that Comparative Example 1 without the silver complex exhibited low thermal conductivity of around 22 W/mK. This low level of thermal conductivity makes it unsuitable for dissipating the heat generated by the SiC chip.

In addition, in the case of Comparative Example 2 out of the curing agent content, Comparative Example 3 in which the catalyst exceeds 2.2 parts by weight, and Comparative Example 4 in which the silver complex compound exceeds 1.1 parts by weight, it was confirmed that the thermal conductivity and adhesive strength were significantly lowered, The cycle test also failed.

Comparative Example 4 was judged to be a result of a decrease in dispersibility and an increase in viscosity due to an excess of the silver complex.

[Table 6]

[Table 7]

Through Table 7, the mixing ratio of additives such as polyester dispersant and CSR affects the adhesive strength, thermal conductivity, and modulus of the solder paste composition, but regardless of the presence or absence of the dispersant, thermal conductivity of 100W/mK or more, 1kgf/mm ² or more It was confirmed that adhesive strength could be secured and that it was possible to pass the thermal cycle test.

Comparative Example 5 relates to a composition in which all additives are removed from the composition of Example 11.

As a result, in spite of the almost similar composition, Example 11 passed, while Comparative Example 5 failed in the thermal cycle test.

It was judged that this was because cracks occurred due to thermal and mechanical stress caused by rapid temperature due to high modulus.

Therefore, it was confirmed that an additive capable of reducing the modulus of butadiene, acrylate, polybutadiene, glycol-based epoxy, etc. is needed to secure an appropriate modulus.

[Table 8]

Referring to Table 8, the technology of the present invention can complete the process for about 32 minutes at 250° C. or less, thereby remarkably solving the problems of the prior art and reducing the process time at the same time, thereby contributing to mass productivity.

In addition, since it has a specific resistance and thermal conductivity close to that of silver even after heat treatment, there is an advantage in that package performance is maintained with little change in package resistance even after a thermal cycle test.

As described above, the present invention has been described with reference to the illustrated drawings, but the present invention is not limited by the embodiments and drawings disclosed in this specification, and various methods can be obtained by those skilled in the art within the scope of the technical spirit of the present invention. It is obvious that variations can be made. In addition, although the effects according to the configuration of the present invention have not been explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the configuration should also be recognized.

Claims (9)

metal powder;
an epoxy resin containing a nitrogen atom and a lone pair of electrons;
hardener;
metal complexes;
catalyst; and
Additive; Solder paste composition comprising.
According to claim 1,
The epoxy resin is a solder paste composition comprising a glycidyl amine-based epoxy resin.
According to claim 1,
The metal complex is a solder paste composition having a peak of a metal-oxygen group at a wavelength of 881 to 429 cm ^-1 in the FT-IR spectrum.
According to claim 1,
The metal complex compound is a paste composition for solder in which -C=O asymmetric stretching peaks exist at a wavelength of 1505 to 1510cm ^-1 in the FT-IR spectrum.
According to claim 1,
The metal powder is a solder paste composition comprising silver (Ag).
According to claim 1,
With respect to 100 parts by weight of the metal powder,
1 to 5 parts by weight of an epoxy resin containing a nitrogen atom and including a lone pair of electrons;
0.1 to 1.1 parts by weight of a metal complex,
0.01 to 2.0 parts by weight of a catalyst, and
0.5 to 5 parts by weight of an additive,
The epoxy resin: curing agent mixing ratio is 1:1 to 1:2 by weight of the solder paste composition.
According to claim 1,
The curing agent is a solder paste composition comprising an acid anhydride-based curing agent.
According to claim 1,
The catalyst is a solder paste composition comprising an imidazole-based catalyst.
According to claim 1,
The additive is a solder paste composition comprising an additive for reducing modulus.

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