Disclosure of Invention
The application provides a modified organic silicon resin for preparing a conductive adhesive, the conductive adhesive and a preparation method thereof, which aim to solve the problem that the bonding effect of a common addition type organic silicon conductive adhesive on most materials is not ideal.
In a first aspect, the present application provides a modified silicone resin for preparing a silicone conductive adhesive, where the structural formula of the modified silicone resin is:
wherein Me is H or CH3, m is an integer of 100-10000, and n is an integer of 1-5.
In the first aspect, the modified silicone resin is specifically a series of acryloxy-modified silicone resins containing a plurality of polar groups. The acryloxy modified organic silicon resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to a bonded substrate can be improved, the better falling resistance of a crystal device is achieved, and the mechanical reliability of the crystal device is improved.
In the first aspect, the modified silicone resin has a characteristic absorption peak of a carbon-oxygen single bond in a wavelength range of 8um ± 0.5um, a characteristic absorption peak of a carbon-oxygen double bond in a wavelength range of 6um ± 0.5um, and a stretching vibration absorption peak of a carbon-hydrogen bond in a wavelength range of 3um ± 0.5 um. The modified silicone resin is said to contain acryloxy groups.
In a second aspect, embodiments herein provide a method of preparing a modified silicone resin, the method comprising;
placing acrylic resin terminated by acryloyloxy and hydrogen-containing silicone oil in a reaction solvent, and carrying out addition reaction under the action of an inhibitor and a catalyst;
extracting the modified organic silicon resin from the reaction product.
In a second aspect, the properties of hydrogen-containing silicone oils are altered by grafting an acryloxy-terminated acrylic resin into the hydrogen-containing silicone. The obtained modified organic silicon resin contains a plurality of polar groups and has strong bonding strength. The acryloxy modified organic silicon resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to a base material can be improved, the better anti-falling performance of a crystal device is achieved, and the mechanical reliability of the crystal device is improved. Meanwhile, the flexibility of the conductive adhesive can be kept.
In an alternative implementation of the second aspect, the reaction temperature of the addition reaction is from 100 ℃ to 200 ℃.
In an alternative implementation of the second aspect, the extraction of the modified silicone resin from the reaction product comprises: distilling the reaction solvent and the small molecular reactant from the reaction product at low pressure; adsorbing the residual catalyst by adding activated carbon; filtering to remove the active carbon to obtain the modified organic silicon resin liquid.
In an alternative implementation of the second aspect, the molar ratio of H groups in the hydrogen-containing silicone oil to acryloxy groups in the acrylic resin terminated with acryloxy groups is 8:1-1:1. By controlling the molar ratio of the introduced acryloxy groups to the hydrogen groups, the flexibility of the modified silicone resin system can be maintained while the acryloxy groups and the polar functional groups are introduced to improve the bonding strength.
In an alternative implementation of the second aspect, the acrylic resin terminated with an acryloxy group has the formula:
wherein n is an integer of 1 to 5.
In an alternative implementation manner of the second aspect, the hydrogen-containing silicone oil has a structural formula:
wherein Me is H or CH3, and m is an integer of 100-10000.
In a third aspect, the present application further provides a conductive adhesive, including: 0.5-5 parts of the modified organic silicon resin provided by the first aspect, 5-15 parts of methyl vinyl MQ silicon resin, 0-90 parts of micron-sized silver powder, 1-50 parts of nano-sized low-temperature sintered silver powder, 0.1-1 part of 3- (methacryloyloxy) propyl trimethoxy silane, 0.1-1 part of borate coupling agent, 1-10 parts of solvent, 0.1-0.5 part of inhibitor and 0.1-0.5 part of platinum catalyst.
Wherein, the methyl vinyl MQ silicone resin comprises vinyl and a monofunctional siloxane chain link R 3 SiO 1/2 With tetrafunctional siloxane linkages SiO 4/2 The network polysiloxane of (2).
In a third aspect, on the one hand, the acryloxy modified organic silicon resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to the base material can be improved, better falling resistance of the crystal device is achieved, and the mechanical reliability of the crystal device is improved. Meanwhile, the flexibility of the conductive adhesive can be kept. On the other hand, the nanoscale low-temperature sintered silver powder is introduced into the conductive adhesive, so that the nanoscale low-temperature sintered silver powder in the adhesive can be partially welded with the bonded metal base material during high-temperature curing, and the cohesion of the conductive adhesive and the bonding performance of the conductive adhesive and the bonded base material are greatly improved.
In an alternative embodiment of the third aspect, the inhibitor is selected from any one or more of diallyl maleate, diethyl fumarate, alkynols, 1-ethynyl-1-cyclohexanol.
In an alternative implementation manner of the third aspect, the platinum catalyst is one or more of chloroplatinic acid-type catalyst and Karster platinum-gold catalyst.
In a fourth aspect, the present application further provides a preparation method of the conductive adhesive, including:
weighing 0.5-5 parts by weight of the modified organic silicon resin, 5-15 parts by weight of methyl vinyl MQ silicon resin, 0-90 parts by weight of micron-sized silver powder, 1-50 parts by weight of nano-sized low-temperature sintered silver powder, 0.1-1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 0.1-1 part by weight of borate ester coupling agent, 1-10 parts by weight of solvent, 0.1-0.5 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst, wherein the weight of the modified organic silicon resin is the same as that of the modified organic silicon resin in the claim 1;
sequentially adding the weighed modified organic silicon resin, methyl vinyl MQ silicon resin, micron-sized silver powder, nano-sized low-temperature sintered silver powder, an inhibitor and part of solvent into a stirrer, and stirring for reaction for 2-4 hours;
putting the stirred materials into a three-roller grinding machine for grinding and dispersing to obtain mixed materials;
dissolving the weighed platinum catalyst, 3- (methacryloyloxy) propyl trimethoxy silane and borate coupling agent in the residual solvent, adding the solution into the mixed material, grinding and dispersing the mixture by a grinder, and adding the mixture into a stirrer to stir to obtain a mature material;
and adjusting the viscosity of the cured material to a target value, filtering, and defoaming in vacuum to obtain the conductive adhesive.
In the fourth aspect, the acryloxy modified organic silicon resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to a base material and the high and low temperature resistance of the conductive adhesive can be improved, the better anti-falling performance of a crystal device is achieved, and the mechanical reliability of the crystal device is improved. Meanwhile, the flexibility of the conductive adhesive can be kept. On the other hand, the nanoscale low-temperature sintered silver powder is introduced into the conductive adhesive, so that the nanoscale low-temperature sintered silver powder in the adhesive can be partially welded with the adhered base material during high-temperature curing, and the cohesion of the conductive adhesive and the adhesion of the conductive adhesive and the base material are greatly improved.
Detailed Description
In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort shall fall within the protection scope of the present application.
As shown in fig. 1A, the conductive adhesive 104 and the object to be bonded (the base 102) form a bonding structure. In the adhesive joint structure, an electric double layer exists at the interface of the adhesive and the bonded object, and the electrostatic attraction action of the electric double layer is the action of the adhesive joint. When the adhesive is peeled off from the surface of the adherend, a potential difference is generated between the adhesive and the surface of the adherend. When the peeling distance is increased to a certain limit value, a discharge phenomenon will occur between the adhesive and the bonded object, and the instantaneous discharge energy at the moment is equal to the bonding work of the bonding structure. Based on this, the bonding work can be calculated by calculating the instantaneous discharge energy, and the size of the bonding work can represent the size of the bonding force or the bonding strength. Wherein the work of bonding can be calculated according to the following formula:
wherein Wa represents the work of adhesion, Q represents the surface density of electric charges, ε represents the dielectric constant of the medium, and h represents the discharge distance.
As can be seen from the above method for calculating the bonding work, when the dielectric constant and the discharge distance of the medium are constant, the larger the surface density of the electric charge is, the larger the instantaneous discharge energy is, that is, the bonding work is. And because the stronger the polarity of the adhesive, the higher the surface density of the electric charge, the stronger the polarity of the adhesive, the greater the bonding work, and the stronger the bonding strength.
The application relates to a modified organic silicon resin, a preparation method of the modified organic silicon resin, a conductive adhesive containing the modified organic silicon resin and a preparation method of the conductive adhesive. Wherein the modified organic silicon resin is specifically acryloxy modified organic silicon resin containing a plurality of polar groups. The acryloxy modified organic silicon resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to a base material can be improved, the better falling resistance performance of a crystal device is achieved, and the mechanical reliability of the crystal device is improved.
In certain embodiments, the modified silicone resin has the structural formula:
wherein Me is H or CH 3 M is an integer of 100 to 10000, and n is an integer of 1 to 5.
In some embodiments, the silicone resin can be prepared by an addition reaction between an acryl resin terminated with an acryloxy group and a hydrogen-containing silicone oil as reactants. Wherein, the acrylic resin terminated with acryloyloxy can be acrylic resin terminated with monofunctional methacryloyloxy group, and also can be acrylic resin terminated with bifunctional methacryloyloxy group; the hydrogen-containing silicone oil is the hydrogen-containing silicone oil containing terminal group H and side group H.
In certain embodiments, the acrylic resin terminated with acryloxy groups has the formula:
wherein n is an integer of 1 to 5.
In certain embodiments, the hydrogen-containing silicone oil has the formula:
wherein Me is H or CH 3 And m is an integer of 100 to 10000.
Fig. 2 is a flow chart of a method of preparing a modified silicone resin, as shown in fig. 2, shown in some embodiments of the present application, the method comprising:
s201, placing acrylic resin terminated by acryloyloxy and hydrogen-containing silicone oil in a reaction solvent, and carrying out addition reaction at 100-200 ℃ under the action of an inhibitor and a catalyst.
Alternatively, the molar ratio of the H group in the hydrogen-containing silicone oil to the acryloyloxy group in the acrylic resin terminated with acryloyloxy group is 8:1-1:1. By controlling the molar ratio of the introduced acryloxy group to the hydrogen group, the flexibility of the modified organic silicon resin system can be kept while the acryloxy group and the polar functional group are introduced to improve the bonding strength.
Alternatively, the reaction solvent is toluene.
Alternatively, the catalyst is a platinum catalyst, such as chloroplatinic acid or a platinum on castrate catalyst. The weight percentage of the catalyst in the whole reaction system is 0.1-1%.
Alternatively, the inhibitor is ethanol.
S202, extracting the modified organic silicon resin from the reaction product.
Specifically, a reaction solvent and a small molecular reactant are distilled from a reaction product at a low pressure; adsorbing the residual catalyst by adding activated carbon; filtering to remove the active carbon to obtain the modified organic silicon resin liquid.
In certain embodiments, the two terminal groups of the acrylic resin terminated with an acryloxy group are methacryloxy and acryloxy groups, respectively, having the formula:
wherein n is an integer of 1 to 5.
The structural formula of the hydrogen-containing silicone oil is as follows:
wherein Me is H or CH 3 And m is an integer of 100 to 10000.
In certain embodiments, during the addition reaction of the acrylic resin terminated with acryloxy groups with hydrogen-containing silicone oil described above, acryloxy groups may be added with pendant groups H, one or more terminal groups H, on the backbone of the hydrogen-containing silicone oil molecule. According to the difference of the position and the quantity of H which takes part in the reaction of the hydrogen-containing silicone oil, the reaction products are different. Specifically, the addition reaction formulae of the above acrylic resin terminated with acryloyloxy group and hydrogen-containing silicone oil are as shown in the following reaction formulae (1) to (7).
Reaction formula (1):
as can be seen from reaction formula (1), the C = C bonds of the methacryloxy groups and the acryloxy groups at both ends of the acrylic resin are opened and grafted to the pendant groups H of the hydrogen-containing silicone oil, respectively, to produce the modified silicone resin having the structural formula (1) described above.
Reaction formula (2):
as can be seen from reaction formula (2), the C = C bond of the methacryloxy group at one end of the acrylic resin is opened and grafted to the side group H of the hydrogen-containing silicone oil, and the C = C bond of the acryloxy group at the other end of the acrylic resin is opened and grafted to the end group H of the hydrogen-containing silicone oil, resulting in the modified silicone resin having the above structural formula (2).
Reaction formula (3):
as can be seen from reaction formula (3), the C = C bond of the methacryloxy group at one end of the acrylic resin is opened and grafted to the terminal group H of the hydrogen-containing silicone oil, and the C = C bond of the acryloxy group at the other end of the acrylic resin is opened and grafted to the side group H of the hydrogen-containing silicone oil, resulting in the modified silicone resin having the above structural formula (3).
Reaction formula (4):
as can be seen from reaction formula (4), the C = C bonds of the methacryloxy groups and the acryloxy groups at both ends of the acrylic resin are opened and grafted to both terminal groups H of the hydrogen-containing silicone oil, respectively.
Reaction formula (5):
as can be seen from the reaction formula (5), the methacryloxy group at one end of the acrylic resin is grafted to the terminal group H on the main chain of the hydrogen-containing silicone oil molecule, and the acryloxy group at the other end of the acrylic resin is grafted to the side group H on the main chain of the same hydrogen-containing silicone oil molecule, resulting in the modified silicone resin having the structural formula (5) above.
Reaction formula (6):
as can be seen from the reaction formula (6), the methacryloxy group at one end of the acrylic resin is grafted to the pendant group H on the main chain of the hydrogen-containing silicone oil molecule, and the acryloxy group at the other end of the acrylic resin is grafted to the terminal group H on the main chain of the same hydrogen-containing silicone oil molecule, resulting in the modified silicone resin having the structural formula (6) above.
Reaction formula (7):
as can be seen from the reaction formula (7), the methacryloxy groups and the acryloxy groups at both ends of the acrylic resin are grafted to the side group H and the end group H on the same main chain of the hydrogen-containing silicone oil molecule, and the modified silicone resin with the structural formula (7) is generated.
Fig. 3 is an infrared spectrogram of the modified silicone resin provided in the embodiment of the present application, as shown in fig. 3, a characteristic absorption peak of a carbon-oxygen single bond appears at a wavelength (8 um ± 0.5 um), a characteristic absorption peak of a carbon-oxygen double bond appears at a wavelength (6 um ± 0.5 um), and a stretching vibration absorption peak of a carbon-hydrogen bond appears at a wavelength (3 um ± 0.5 um), which indicates that an acryloyloxy group is introduced into the modified silicone resin.
As described above, on one hand, the acryloxy modified silicone resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to the base material can be improved, the better anti-falling performance of the crystal device is achieved, and the mechanical reliability of the crystal device is improved. Meanwhile, the flexibility of the conductive adhesive can be kept.
In certain embodiments, the electrically conductive adhesive specifically comprises: 0.5-5 parts of the modified organic silicon resin, 5-15 parts of methyl vinyl MQ silicon resin, 0-90 parts of micron-sized silver powder, 1-50 parts of nano-sized low-temperature sintered silver powder, 0.1-1 part of 3- (methacryloyloxy) propyl trimethoxy silane, 0.1-1 part of borate coupling agent, 1-10 parts of solvent, 0.1-0.5 part of inhibitor and 0.1-0.5 part of platinum catalyst.
Wherein, the methyl vinyl MQ silicone resin comprises vinyl and a single-functionality siloxane chain link R 3 SiO 1/2 With tetrafunctional siloxane linkages SiO 4/2 The network polysiloxane of (2).
It should be noted that, by introducing the nanoscale low-temperature sintered silver powder into the conductive adhesive, when the conductive adhesive is cured at a temperature above 250 ℃, the nanoscale low-temperature sintered silver powder in the adhesive can be partially welded with the adhered metal base material, so that the cohesive force of the conductive adhesive and the adhesive property of the conductive adhesive with the base material are greatly improved.
In certain embodiments, the inhibitor is selected from any one or more of diallyl maleate, diethyl fumarate, acetylenic alcohols, 1-ethynyl-1-cyclohexanol.
In certain embodiments, the platinum catalyst is one or more of a chloroplatinic acid catalyst, a platinum gold catalyst, or a platinum gold catalyst.
In certain embodiments, the solvent is selected from any one or more of alkane solvents, mineral spirits No. 200, mineral spirits No. 150, and mineral spirits No. D200.
Fig. 4 is a flow chart of a method of preparing a modified silicone resin, as shown in fig. 4, in some embodiments of the present application, the method comprising:
s401, weighing 0.5-5 parts by weight of modified organic silicon resin, 5-15 parts by weight of methyl vinyl MQ silicon resin, 0-90 parts by weight of micron-sized silver powder, 1-50 parts by weight of nano-sized low-temperature sintered silver powder, 0.1-1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 0.1-1 part by weight of borate coupling agent, 1-10 parts by weight of solvent, 0.1-0.5 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst.
S402, sequentially adding the weighed modified organic silicon resin, methyl vinyl MQ silicon resin, micron-sized silver powder, nano-sized low-temperature sintered silver powder, an inhibitor and part of solvent into a stirrer, and stirring for reaction for 2-4 hours.
And S403, putting the stirred materials into a three-roll grinder, grinding and dispersing to obtain a mixed material.
In a more specific implementation manner, in S403, the material stirred in S402 is put into a three-roll grinder to be ground and dispersed, so as to obtain a mixed material a; and then, continuously grinding and dispersing the mixed material A for 3-5 times by a three-roll grinder, and keeping the distance between rolls at 15-25um to obtain a mixed material B.
S404, dissolving the weighed platinum catalyst, 3- (methacryloyloxy) propyl trimethoxy silane and borate coupling agent in the residual solvent, adding the solution into the mixed material obtained in the S403, grinding and dispersing the mixed material by a grinder, adding the ground material into a stirrer, and stirring the ground material to obtain a cured material.
S405, adjusting the viscosity of the curing material to a target value, filtering, and defoaming in vacuum to obtain the conductive adhesive.
The modified silicone resin and the preparation method thereof, the conductive adhesive and the preparation method thereof provided by the present application are described below by specific examples, and the performance test is performed on the conductive adhesive samples prepared in the examples.
Example 1
S101, according to the molar ratio of H group in the hydrogen-containing silicone oil to the acryloyloxy group in the acrylic resin of 8:1, putting the acrylic resin blocked by the bifunctional acryloyloxy group and the hydrogen-containing silicone oil containing the terminal group H and the side group H into toluene, heating to 150 ℃ under the action of ethanol (inhibitor) and Kanstedt platinum catalyst (catalyst), and carrying out addition reaction at 150 ℃.
S102, distilling a reaction solvent and a small molecular reactant from the reaction product at low pressure; adsorbing the residual catalyst by adding activated carbon; filtering to remove the active carbon to obtain semitransparent modified organic silicon resin liquid.
Example 2
Example 2 differs from example 1 in that the molar ratio of H groups in the hydrogen-containing silicone oil to acryloxy groups in the acrylic resin is 4:1.
Example 3
S1, weighing 2 parts by weight of the modified organic silicon resin prepared in the example 1, 10 parts by weight of methyl vinyl MQ silicon resin, 40 parts by weight of micron-sized silver powder, 8 parts by weight of nano-sized low-temperature sintered silver powder, 1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 1 part by weight of borate coupling agent, 4 parts by weight of solvent, 0.1 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst.
More specifically, the model of the methyl vinyl MQ silicon resin adopted in this embodiment is nibo ryegrass S0826H, the model of the micron-sized silver powder adopted is TC-505 silver powder produced by jieli, the model of the nano-sized low-temperature sintered silver powder adopted is LS0305 produced by metal of jigon Tian Gui, the solvent adopted is D150 solvent oil, and the inhibitor adopted is alkynol.
And S2, sequentially adding the weighed modified organic silicon resin, methyl vinyl MQ silicon resin, micron-sized silver powder, nanoscale low-temperature sintered silver powder, an inhibitor and 70% of solvent into a stirrer, and stirring for reaction for 2-4 hours.
S3, putting the stirred materials into a three-roller grinding machine for grinding and dispersing, and keeping the roller spacing at 10 mu m to obtain a mixed material A; and (3) continuously grinding and dispersing the mixed material A for 5 times by a three-roll grinder, and keeping the distance between the rolls at 25um to obtain a mixed material B.
And S4, dissolving the weighed platinum catalyst, 3- (methacryloyloxy) propyl trimethoxy silane and borate coupling agent in the residual 30% of solvent, adding the solution into the mixed material B, grinding and dispersing the solution by a grinder, adding the mixture into a stirrer, and stirring the mixture to obtain a mature material.
And S5, adjusting the viscosity of the cured material to a target value of 10000-30000mPa & S, filtering, and defoaming in vacuum to obtain the conductive adhesive.
Example 4
The difference between the embodiment 4 and the embodiment 3 is that the raw materials are weighed according to the following parts by weight: weighing 2 parts by weight of the modified silicone resin prepared in example 1 and 10 parts by weight of methyl vinyl MQ silicone resin,24 parts by weight of micron-sized silver powder and 24 parts by weight of silver powder Nano-scale low-temperature sintered silver powder1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 1 part by weight of borate coupling agent, 4 parts by weight of solvent, 0.1 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst.
Example 5
The difference between the embodiment 5 and the embodiment 3 is that the raw materials are weighed according to the following parts by weight: weighing 2 parts by weight of the modified silicone resin prepared in example 1 and 10 parts by weight of methyl vinyl MQ silicone resin,48 parts by weight of nano-scale low-temperature sintered type Silver powder1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 1 part by weight of borate coupling agent, 4 parts by weight of solvent, 0.1 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst.
Example 6
The difference between the embodiment 6 and the embodiment 3 is that the raw materials are weighed according to the following parts by weight: weighing2 parts by weight of Modified Silicone resin prepared in example 210 parts by weight of methyl vinyl MQ silicone resin,40 parts of micron-sized silver powder and 8 parts of silver powder Part nano-scale low-temperature sintered silver powder1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 1 part by weight of borate coupling agent, 4 parts by weight of solvent, 0.1 part by weight of inhibitor and 0.1-0 part by weight of solvent5 parts by weight of a platinum catalyst.
Example 7
The difference between the embodiment 7 and the embodiment 3 is that the raw materials are weighed according to the following parts by weight: weighing 2 parts by weight of the modified silicone resin prepared in example 2 and 10 parts by weight of methyl vinyl MQ silicone resin,24 parts by weight of micron-sized silver powder and 24 parts by weight of silver powder Nano-scale low-temperature sintered silver powder1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 1 part by weight of borate coupling agent, 4 parts by weight of solvent, 0.1 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst.
Example 8
The difference between the embodiment 8 and the embodiment 3 is that the raw materials are weighed according to the following parts by weight: 2 parts by weight of the modified silicone resin obtained in example 2, 10 parts by weight of a methyl vinyl MQ silicone resin, a,48 parts by weight of nano-scale low-temperature sintered type Silver powder1 part by weight of 3- (methacryloyloxy) propyl trimethoxy silane, 1 part by weight of borate coupling agent, 4 parts by weight of solvent, 0.1 part by weight of inhibitor and 0.1-0.5 part by weight of platinum catalyst.
The conductive adhesives prepared in examples 3-8 above were sequentially identified as samples 1-6. Adding type organosilicon conductive adhesive with 3303G brand produced by certain enterprises in Japan is taken as comparative example 1; an addition type silicone conductive paste of trade name XA-5940 manufactured by a certain company of Japan was used as comparative example 2. The performance of samples 1-6 and comparative examples 1-2 were tested according to the national standard GB/T35494, with the test items including the curing conditions, volume resistance, hardness, tensile rate, ceramic/glass shear strength, gold-plated carrier and silver-plated wafer tension, and 1 meter height drop resistance, and the test results are shown in Table 1.
TABLE 1
As can be seen from table 1, in comparison with comparative examples 1 and 2, samples 1, 2, 4 and 5 have superior adhesive strength, electrical conductivity, flexibility and drop resistance. In addition, different resin synthesis methods, different silver powder types and different acrylate modified silicone resin selections all affect the performance of the conductive adhesive.
According to the embodiments, the acryloxy modified organic silicon resin containing a plurality of polar groups is added into the conductive adhesive, so that the bonding strength of the conductive adhesive to the base material can be improved, the better anti-falling performance of the crystal device is achieved, and the mechanical reliability of the crystal device is improved. Meanwhile, the flexibility of the conductive adhesive can be kept. On the other hand, the nanoscale low-temperature sintered silver powder is introduced into the conductive adhesive, so that the nanoscale low-temperature sintered silver powder in the adhesive can be partially welded with the bonded metal base material during high-temperature curing, and the cohesion of the conductive adhesive and the bonding performance of the conductive adhesive and the bonded base material are greatly improved.
The above list of examples is merely illustrative of possible embodiments of the present invention and is not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the process of the present invention are intended to be included within the scope of the present invention.
The same and similar parts among the various embodiments in this specification may be referred to each other. The above-described embodiments of the present invention should not be construed as limiting the scope of the present invention.