JP6774727B2 - Method for manufacturing joint reinforcing composition and joint reinforcing portion - Google Patents

Description

The present invention relates to a composition for reinforcing a joint and a method for manufacturing a joint reinforcing portion.

When a material to be joined such as an electronic component is mounted on a substrate, solder bonding using a solder alloy is performed.

In recent years, substrates and materials to be joined such as electronic components used in electronic devices have been further miniaturized and made thinner, and many micro-sized materials to be joined are mounted on the substrate. Along with this, the region to be soldered is also required to be fine and miniaturized. In such electronic devices, especially automobile electronic devices to which further functions will be added in the future, small and many materials to be bonded are mounted on the in-vehicle substrate mounted on the electronic devices. It is expected that the reliability required for fine and fine solder joints (hereinafter referred to as "fine joints") will be further increased.

Conventionally, for those that are finely bonded such as package parts, from the viewpoint of reliability, the solder joint between the substrate and the material to be joined is reinforced by filling and curing the resin by a method such as underfilling. Was there. However, the finer the components mounted on the board, the closer each solder joint and the board and the material to be joined become closer. Therefore, for example, in the case of so-called capillary underfill in which resin is filled after solder joining, soldering is performed. There is a problem that it takes time to fill the resin between the joints.

Further, a resin may be applied first to join the material to be joined, and an epoxy resin is often used as this resin (Patent Document 1). However, since epoxy resin has the property of easily reacting with it depending on the type of organic acid or amine used in combination with it, the reaction between the two starts from the stage where they are mixed, causing deterioration of shelf life and increase in viscosity of the mixture. , The reinforcing effect of the joint may be hindered.

Japanese Unexamined Patent Publication No. 2016-23299

INDUSTRIAL APPLICABILITY The present invention provides a joint reinforcing composition capable of achieving a good shelf life and viscosity without selecting an activator to be used, forming a good joint portion and exerting a reinforcing effect thereof without trouble even in fine bonding. An object of the present invention is to provide a method for manufacturing a joint reinforcing portion using this.

(1) The bonding reinforcing composition of the present invention contains (A) a thermosetting resin and (B) an activator, and the thermosetting resin (A) is a maleimide compound (A-1) having a maleimide skeleton. ) Is included.

(2) In the configuration described in (1) above, the maleimide compound (A-1) is characterized by having a plurality of maleimide groups at the terminal or side chain.

(3) In the configuration according to (1) or (2) above, as the maleimide compound (A-1), at least one of the maleimide compounds represented by the following general formulas (1) and (2) is used. Its characteristic is to include it.

(Wherein, Y represents a dimer diamine residue or aliphatic diamine residue derived from polymerized fatty acid having 36 or 54 carbon, Z is an imide compound residue consisting of the reaction of tetracarboxylic acid dianhydride with a primary amine Represents a group, where P represents an integer from 0 to 10.)

(Wherein, R ₈ R ₁ to Represents any of hydrogen, hydroxyl, methyl or ethyl, X represents no organic group intervening, or C, H, any organic group consisting of O. )

(4) The composition according to any one of (1) to (3) above, wherein the bonding reinforcing composition of the present invention further contains (C) a curing agent.

(5) In the configuration according to any one of (1) to (4) above, the curing agent (C) is at least selected from imidazole compounds, imidazole salts, peroxides, melamine and amines. Its characteristic is that it is one kind.

(6) In the configuration according to any one of (1) to (5) above, the bonding reinforcing composition of the present invention is used for reinforcing the solder bonding between the substrate and the material to be bonded, and the substrate is said to be reinforced. The characteristic of the metal for joining, which forms a joint portion for soldering the material to be joined, is that the viscosity of the metal for joining at the time of solder melting is 10 Pa · s or less, and the viscosity at 300 ° C. is 100 Pa · s or more. To do.

(7) The method for manufacturing a joint reinforcing portion of the present invention includes a step of providing a metal for joining at at least one predetermined position on the substrate and the material to be joined, and the above (7) at a predetermined position of the substrate or the material to be joined. By the step of applying the bonding reinforcing composition according to any one of 1) to (6), the step of placing the material to be bonded at a predetermined position on the substrate and heating it, and heating. The metal for joining is melted to form a joining portion for joining the substrate and the material to be joined, and the joining made of a cured product of the joining reinforcing composition is formed in at least one of a region abutting the joining portion and a region in the vicinity thereof. Its characteristic is that it includes a step of forming a reinforcing portion.

The joint reinforcing composition and the method for producing a joint reinforcing portion of the present invention realize a good shelf life and viscosity without selecting an activator to be used, and form a good joint portion and reinforce it without hassle even in fine bonding. It can be effective.

The graph which showed the heating profile condition in the solder bondability test which concerns on the composition for joint reinforcement of an Example and a comparative example. The graph which showed the viscosity measured in the rheometer test concerning the composition for joint reinforcement of Example 1 and Comparative Example 2.

An embodiment of the composition for reinforcing the joint and the method for producing the joint reinforcing portion of the present invention will be described in detail below.

1. 1. Bond Reinforcing Composition The bonding reinforcing composition according to the present embodiment contains (A) a thermosetting resin and (B) an activator.

(A) Thermosetting Resin As the thermosetting resin (A) used in the bonding reinforcing composition of the present embodiment, (A-1) a maleimide compound having a maleimide skeleton is preferably used. As the maleimide compound (A-1), a compound having a plurality of maleimide groups at the terminal or side chain is preferably used.
Such a maleimide compound (A-1) is excellent in heat resistance, insulating property, moisture resistance and low dielectric property, and is difficult to react with the activator (B). Therefore, the joint reinforcing composition of the present embodiment can suppress an increase in its viscosity, and the joint reinforcing portion formed by using the composition can realize good heat resistance, insulation and moisture resistance.

As the maleimide compound (A-1), for example, a polyfunctional aliphatic maleimide compound or a polyfunctional aromatic maleimide compound is preferably used. Further, as the polyfunctional aliphatic compound, a maleimide compound (A-1) represented by the following general formula (1) is preferably used.

(Wherein, Y represents a dimer diamine residue or aliphatic diamine residue derived from polymerized fatty acid having 36 or 54 carbon, Z is an imide compound residue consisting of the reaction of tetracarboxylic acid dianhydride with a primary amine Represents a group, where P represents an integer from 0 to 10.)

The maleimide compound (A-1) represented by the general formula (1) is obtained by reacting, for example, a diamine derived from a dimer acid having 36 or 54 carbon atoms with a maleic anhydride to obtain bismaleamic acid. Obtained by dehydration ring closure.

Examples of the maleimide compound (A-1) represented by the general formula (1) include 2- [8- (3-hexyl-2,6-dioctylcyclohexyl) octyl] pyromeriticdiimide oligomer. As commercially available products, for example, BMI-689, BMI-1500, BMI-1700, BMI-3000, and BMI-5000 (all manufactured by Designer Moleculars Inc.) are preferably used.

Further, as the polyfunctional aromatic maleimide compound, the maleimide compound (A-1) represented by the following general formula (2) is preferably used.

(Wherein, R ₈ R ₁ to Represents any of hydrogen, hydroxyl, methyl or ethyl, X represents no organic group intervening, or C, H, any organic group consisting of O. )

The maleimide compound (A-1) represented by the general formula (2) can be obtained, for example, by dehydration imidization of an aromatic diamine and maleic anhydride.

Examples of the maleimide compound represented by the general formula (2) include 4,4'-diphenylmethane bismaleimide, bisphenol A diphenyl ether bismaleimide, 2,2-bis [4- (4-maleimide phenoxy) phenyl] propane, and 3 , 3'-Dimethyl-5,5'-diethyl-4, 4'-diphenylmethane bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenylsulfone bismaleimide and the like. Examples of commercially available products include BMI, BMI-70, and BMI-80 (all manufactured by KAI Kasei Co., Ltd.).

As the maleimide compound (A-1), bisphenol A diphenyl ether bismaleimide is particularly preferably used.
Further, the maleimide compound (A-1) may be used alone or in combination of a plurality of types, but when the polyfunctional aromatic maleimide compound is used, it may be used in combination with the polyfunctional aliphatic maleimide compound. More preferred.

The blending amount of the maleimide compound (A-1) is preferably 10% by weight to 100% by weight with respect to the total amount of the thermosetting resin (A). The blending amount thereof is more preferably 20% by weight to 90% by weight, and particularly preferably 30% by weight to 80% by weight.
When the polyfunctional aromatic maleimide compound and the polyfunctional aliphatic maleimide compound are used in combination, the blending ratio thereof is 5:95 to 95: 5 (polyfunctional aromatic maleimide compound: polyfunctional aliphatic maleimide compound).

Further, as the thermosetting resin (A), for example, an epoxy resin, an unsaturated polyester resin, or a phenol resin other than the maleimide compound (A-1) as long as the effect of the bonding reinforcing composition of the present embodiment is not impaired. , Rossin resin, acrylic resin, maleic acid resin, butyral resin and other thermosetting resins can also be used.

The blending amount of the thermosetting resin (A) is preferably 5% by weight to 95% by weight with respect to the total solid content of the bonding reinforcing composition according to the present embodiment. The blending amount thereof is more preferably 20% by weight to 90% by weight, and particularly preferably 30% by weight to 80% by weight.

(B) Activator As the activator (B), for example, an amine salt (inorganic acid salt or organic acid salt) such as a hydrogen halide of an organic amine, an organic acid, an organic acid salt, or an organic amine salt may be blended. Can be done. More specifically, diphenylguanidine hydrobromide, cyclohexylamine hydrobromide, diethylamine salt, acid salt, succinic acid, adipic acid, sebacic acid and the like can be mentioned. Of these, adipic acid is particularly preferably used. In addition, these can be used individually by 1 type or in combination of a plurality of types.

The bonding reinforcing composition of the present embodiment contains the maleimide compound (A-1) as the main thermosetting resin (A), whereby the thermosetting resin (A) and the activator (B) are mixed. By suppressing the reaction, the increase in viscosity can be suppressed and a good shelf life can be realized. Further, since the active force of the activator (B) can be maintained in a high state, a bonding metal is provided on a substrate coated with the bonding reinforcing composition and heated to form a bonding portion and a bonding reinforcing portion. Good meltability of the bonding metal can be realized even when forming and.
Since the increase in viscosity can be suppressed, the bonding reinforcing composition of the present embodiment can be suitably used even if it is solvent-free.

The blending amount of the activator (B) is preferably 3% by weight to 50% by weight with respect to the total solid content of the bonding reinforcing composition. The blending amount thereof is more preferably 5% by weight to 30% by weight, and particularly preferably 8% by weight to 20% by weight.

(C) Curing Agent (C) Curing Agent can be further added to the bonding reinforcing composition of the present embodiment. By using the curing agent (C) in combination, the hardness and elastic modulus of the formed joint reinforcing portion can be increased.
Examples of the curing agent (C) include imidazole compounds, imidazole compounding, peroxides, melamines and amines. Of these, imidazole compounds are particularly preferably used. In addition, these can be used individually by 1 type or in combination of a plurality of types.

Examples of the imidazole compound include imidazole, benzoimidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and the like. Examples thereof include 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole.

Examples of the imidazole salts include hydrochlorides of imidazole compounds, isocyanuric acid adducts, polyvalent carboxylic acid adducts, and the like.

Examples of the peroxides include organic peroxides such as ketone peroxides, diacyl kill peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peroxides, and percarbonates. Can be mentioned.

Examples of the melamine include melamine and melamine derivatives.

Examples of the amines include dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine. Amine and the like can be mentioned.

As the curing agent (C), any other than the above can be used as long as it promotes the thermosetting of the thermosetting resin (A).

The blending amount of the curing agent (C) is preferably 0.5% by weight to 50% by weight with respect to the total solid content of the bonding reinforcing composition. The blending amount thereof is more preferably 1% by weight to 30% by weight, and particularly preferably 3% by weight to 10% by weight.
It should be noted that the bonding reinforcing composition of the present embodiment can suppress the reaction of the components in the composition and its progress even when the curing agent (C) is blended within the above range due to its composition. , Good viscosity can be maintained.

(D) Tixo agent (D) Tixo agent can be further added to the bonding reinforcing composition of the present embodiment. Examples of the chixo agent (D) include, but are not limited to, castor oil, hydrogenated castor oil, fatty acid amides, and oxyfatty acids. In addition, these can be used individually by 1 type or in combination of a plurality of types.
The blending amount of the thixo agent (D) is preferably 0.1% by weight to 10% by weight with respect to the total solid content of the bonding reinforcing composition. The blending amount thereof is more preferably 0.5% by weight to 5% by weight, and particularly preferably 1% by weight to 3% by weight.

(E) Antioxidant An antioxidant (E) can be further added to the bonding reinforcing composition of the present embodiment. Examples of the antioxidant (E) include hindered phenol compounds (including semi-hindered compounds), phenolic antioxidants, bisphenol antioxidants, polymer antioxidants, triazole antioxidants, and phosphorus oxidation. Inhibitors, sulfur compounds (dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, dilauryl sulfide, 2-mercapto Benz imidazole, 2-mercaptomethylbenzimidazole, 2-mercaptobenzothiazole, dibenzothiazil disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetrakis (2-ethylhexyl) thiuram disulfide, N, N'-diphenylthiourea, (Zinc salt dithiocarbamate, Nt-butyl-2-benzothiazolyl sulfenamide, zinc butylxanthogenate, etc.) and the like can be mentioned. These can be used alone or in combination of two or more.
The blending amount of the antioxidant (E) is preferably 0.01% by weight to 10% by weight with respect to the total solid content of the bonding reinforcing composition. The blending amount thereof is more preferably 0.1% by weight to 8% by weight, and particularly preferably 1% by weight to 5% by weight.

(F) Solvent A solvent (F) can be further added to the bonding reinforcing composition of the present embodiment. As the solvent (F), for example, isopropyl alcohol, ethanol, acetone, toluene, xylene, ethyl acetate, ethyl cellosolve, butyl cellosolve, glycol ether and the like can be used, but the solvent is not limited thereto. In addition, these can be used individually by 1 type or in combination of a plurality of types.
The blending amount of the solvent (F) is preferably 0% by weight to 90% by weight with respect to the total amount of the bonding reinforcing composition. The blending amount thereof is more preferably 10% by weight to 80% by weight, and particularly preferably 20% by weight to 50% by weight.

Further, other resins and additives such as halogens, matting agents, defoaming agents and fillers may be added to the bonding reinforcing composition of the present embodiment.
The blending amount thereof is preferably 0.1% by weight to 10% by weight with respect to the total solid content of the bonding reinforcing composition. The blending amount thereof is more preferably 0.5% by weight to 5% by weight, and particularly preferably 1% by weight to 3% by weight.

The bonding reinforcing composition of the present embodiment can be suitably used for reinforcing the solder bonding of both the solder-bonded substrate and the material to be bonded, which are used in electronic devices and the like.

The bonding reinforcing composition of the present embodiment is used to reinforce the solder bonding between the substrate and the material to be bonded, and when the metal for bonding solder melts to form a joint portion for solder bonding the substrate and the material to be bonded. The viscosity of the solder is preferably 10 Pa · s or less, and the viscosity at 300 ° C. is 100 Pa · s or more. As a method for measuring this viscosity, for example, a rheometer is used, and the bonding reinforcing composition and the powdered bonding metal are placed in a container attached to the rheometer and measured. The bonding reinforcing composition may be applied to at least one of the substrate and the material to be bonded so as to be in contact with the metal for bonding when the bonding reinforcing portion is formed. In this case, the bonding is performed during heating. Since it comes into contact with the metal for joining to improve its meltability and also plays a role of assisting the formation of the solder joint, the viscosity is measured in the state of being combined with the metal for joining. The measurement conditions at that time are heating from room temperature to 300 ° C. under a heating condition of 5 ° C./min, a gap of 0.50 mm, and a frequency of 1 Hz.

That is, the bonding reinforcing composition of the present embodiment has a viscosity of 10 Pa · s or less at the melting temperature of the bonding metal forming the bonding portion for solder bonding the substrate and the material to be bonded, which is exemplified below. preferable. When, for example, Sn-3Ag-0.5Cu solder alloy is used as the bonding metal, the viscosity of the bonding metal at the time of melting (melting temperature: about 217 ° C to about 220 ° C) is 10 Pa · s or less, and 300 ° C. The viscosity of the solder is preferably 100 Pa · s or more. When, for example, Sn-58Bi solder alloy is used as the bonding metal, the viscosity of the bonding metal at the time of melting (about 138 ° C.) is 10 Pa · s or less, and the viscosity at 300 ° C. is 100 Pa · s or more. Is preferable.
By setting the viscosity of the joint reinforcing composition of the present embodiment to the above range, it is possible to provide a joint reinforcing portion having a good hardness after heating while keeping the viscosity up to a certain temperature low.

2. Method for Manufacturing Joint Reinforcement Part Next, a method for manufacturing the joint reinforcement portion using the joint reinforcement composition of the present embodiment will be described. The application of the joint reinforcing composition of the present invention and the method for manufacturing the joint reinforcing portion using the same are not limited to this manufacturing method.

The method for manufacturing the joint reinforcing portion of the present embodiment includes, for example, a step of providing a metal for joining at at least one predetermined position on the substrate and the material to be joined, and the present embodiment at a predetermined position of the substrate or the material to be joined. A step of applying the bonding reinforcing composition of the above, a step of placing the material to be bonded in a predetermined position on the substrate and heating the same, and a step of melting the metal for bonding by heating to melt the substrate and the coating. This includes a step of forming a joint portion for joining the joint material and forming a joint reinforcing portion made of a cured product of the joint reinforcing composition at at least one of the positions where the joint material is in contact with the joint portion and its vicinity thereof. Each step will be described below.

First, regarding the step of providing a metal for bonding at at least one predetermined position on the substrate and the material to be bonded, the metal for bonding includes, for example, an alloy containing tin and lead, tin and lead, and at least one of silver, bismuth and indium. Alloys containing seeds, alloys containing tin and silver, alloys containing tin and copper, alloys containing tin, silver and copper, alloys containing tin and bismuth, and the like can be used. In addition to these, for example, a solder alloy in which tin, lead, silver, bismuth, indium, copper, zinc, gallium, antimony, gold, palladium, germanium, nickel, chromium, aluminum, phosphorus and the like are appropriately combined can be used. it can. It is possible to use elements other than those listed above in the combination.
Among these, alloys containing tin, silver and copper, such as tin-lead alloys, tin-silver alloy solders, tin-silver-copper alloys, tin-silver-copper-bismuth alloys, tin-silver-copper -Indium alloys and tin-silver-copper-bismuth-indium alloys are preferably used. Among these, Sn-3Ag-0.5Cu alloy, Sn-58Bi and the like are particularly preferably used.

Examples of the method of providing the bonding metal on the substrate include mounting of a solder ball made of the metal, plating, coating of a solder paste composition, and the like. The bonding metal is provided on the substrate. Any method can be used as long as it can be used without limitation. Further, a ball grid array package (BGA package) in which solder balls are provided in advance may be used.
The position where the metal for joining is provided is appropriately determined depending on the type of the material to be joined, the application of the substrate, the circuit design, and the like. Further, the metal for joining may be provided on at least one of the substrate and the material to be joined.

Further, the substrate is not limited to those used for mounting and mounting electronic components such as printed wiring boards, silicon wafers, and ceramic package substrates, and can be used as substrates. Further, as the material to be bonded, for example, an electronic component or the like which is bonded on a substrate can be mentioned. The joining may or may not be accompanied by an electrical joining.

Next, regarding the step of applying the bonding reinforcing composition of the present embodiment to a predetermined position of the substrate or the material to be bonded, the position to apply the composition for bonding reinforcing is the type of the material to be bonded and the use of the substrate. And, although it is appropriately determined depending on the circuit design and the like, for example, the region where the metal for joining is provided, the periphery thereof, the vicinity of the corner portion of the substrate and the material to be joined, and the like can be mentioned. Considering the reinforcement of the formed joint and the improvement of the meltability of the metal for joining at the time of forming the joint, it is preferable that the metal is applied to at least one of the region where the metal is provided and its periphery.
Examples of the method for applying the joint reinforcing composition include a method of applying with a spin coater, a dispenser, a jet dispenser, a roller and the like, screen printing, metal mask printing and the like.
The amount and thickness of the bonding reinforcing composition to be applied are appropriately adjusted depending on the size and height of the bonding metal, but it is preferably at least thicker than the height dimension of the bonding metal.

Further, regarding the step of placing the material to be joined at a predetermined position on the substrate and heating it, the position of the material to be joined is appropriately determined depending on the type of the material to be joined, the application of the substrate, the circuit design, and the like. It is determined.
The heating conditions are appropriately determined depending on the type of the bonding metal, particularly the melting temperature. When, for example, a Sn—Ag—Cu based alloy is used as the bonding metal, the preheating conditions can be set to 60 to 120 seconds at a temperature of 150 ° C. to 180 ° C., and the peak temperature can be set to 220 ° C. to 260 ° C. ..
The substrate and the material to be joined may be heated by a so-called thermocompression bonding method in which the substrate and the material to be joined are heated while being pressure-bonded.
Examples of the device used for the heating include a reflow device, a thermocompression bonding device, and the like, and are appropriately selected depending on the heating conditions.

Then, the metal for joining is melted by the heating, and a joining portion for joining the substrate and the material to be joined is formed. Along with this, a joint reinforcing portion made of a cured product of the joint reinforcing composition is formed at at least one of the positions where the joint reinforcing composition is applied, for example, the position where the joint reinforcing composition is in contact with the joint portion and the vicinity thereof.
The joint reinforcing portion is formed by a space formed by the substrate, the joint material, and the joint portion (when an insulating layer is formed on the substrate, the insulating layer, the joint material, and the joint portion are formed. It is preferable that the space is formed so as to fill the space.

According to the method for manufacturing a joint reinforcing portion of the present embodiment, since the joint portion and the joint reinforcing portion are formed at the same time by heating, a good joint portion can be formed without hassle even in a fine joint, and the joint reinforcing portion is used. It can exert a reinforcing effect.
Further, since the joint reinforcing portion is formed by the joint reinforcing composition of the present embodiment, it is excellent in heat resistance, insulating property, moisture resistance and low dielectric property. Further, the joint reinforcing portion has an effect of reducing stress on the solder joint portion in the solder-bonded substrate and the material to be joined.

Further, the electronic circuit board having the joint reinforcing portion formed by the method for manufacturing the joint reinforcing portion of the present embodiment can be suitably used for an electronic device that requires higher reliability such as an electronic device for an automobile.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. The present invention is not limited to these examples.

Each component shown in Table 1 was kneaded to obtain each joint reinforcing composition according to Examples 1 to 5 and Comparative Examples 1 to 3. Unless otherwise specified, the values shown in Table 1 mean% by weight.

* 1 Aromatic bismaleimide compound manufactured by KAI Kasei Co., Ltd. * 2 Aromatic bismaleimide compound manufactured by KAI Kasei Co., Ltd. * 3 Aliphatic bismaleimide compound manufactured by Designer Moleculars Inc. * 4 Fat manufactured by Designer Moleculars Inc. Group bismaleimide compound * 5 Bisphenol F type epoxy resin manufactured by DIC Co., Ltd. * 6 Bifunctional naphthalene type epoxy resin manufactured by DIC Co., Ltd. * 7 Isocyanuric acid EO-modified diacrylate manufactured by Toa Synthetic Co., Ltd. * 8 Okamura Oil Co., Ltd. Eikosan diic acid * 9 Shikoku Kasei Co., Ltd. 2-phenyl-4-methyl-5-hydroxymethylimidazole * 10 Shin Nihon Rika Co., Ltd. Dibenzylidene sorbitol * 11 BASF Japan Co., Ltd. Hindered phenolic antioxidant Agent

1. 1. A copper film having a glass transition temperature of 100 μm was prepared, and each bonding reinforcing composition was printed on the copper film using an applicator so that the thickness was 100 to 200 μm. Each copper film after printing was heated under heating conditions (3 hours at a temperature of 180 ° C.) at which each printed joint reinforcing composition was sufficiently cured to form a cured film on each copper film. Next, each of the obtained cured films was peeled off from each copper film and cut into a size of 40 mm in length × 5 mm in width. Then, using Thermal Mechanical Analysis (hereinafter referred to as TMA), the glass transition temperature of each cured film was measured under the conditions of a temperature rising rate of 10 ° C./min and a temperature range of 30 to 300 ° C., and those having a temperature of 120 ° C. or higher. Was evaluated as ◯, and those below 120 ° C. were evaluated as ×. The results are shown in Table 2. The glass transition temperature was calculated based on the data obtained by TMA.

2. Solder bondability A BGA substrate (mounted on a solder ball having a Sn-3Ag-0.5Cu composition, 0.5 mm pitch, 228 pins) and an FR-4 plate on which a Cu electrode corresponding to the BGA substrate was formed were prepared. The Cu electrodes on the FR-4 substrate are coated with the respective bonding reinforcing compositions, and these are subjected to the heating profile conditions shown in FIG. 1 using a high temperature observation device (product name: SMT Scope, manufactured by Sanyo Seiko Co., Ltd.). Each test substrate was obtained by reflowing at.
Regarding the continuity of each test substrate (whether or not the solder joint is normal and conducting), the case where the continuity was obtained was evaluated as ◯, and the case where the continuity was not obtained was evaluated as x. The results are shown in Table 2.

3. 3. Viscosity Each joint reinforcing composition was placed in a container and allowed to stand at a temperature of 25 ° C. for 2 to 3 hours. After that, the lid of each container was opened, and each joint reinforcing composition in the container was stirred with a spatula for 1 to 2 minutes so as to avoid air contamination. Next, the container was placed in a viscometer (trade name: PCU105, manufactured by Malcolm Co., Ltd.) and stirred at a rotation speed of 10 rpm at a temperature of 25 ° C. for about 3 minutes. After that, the rotation was stopped, and after waiting until the temperature became constant, the temperature was adjusted and the mixture was stirred at a rotation speed of 10 rpm for 3 minutes, and the viscosity was measured. The results are shown in Table 2.

4. 10 ° C Shelf Life The viscosity of each joint reinforcing composition after kneading was measured. Next, each joint reinforcing composition was placed in a container and left at a temperature of 10 ° C. for 30 days, and the viscosity of each joint reinforcing composition after standing was measured. Regarding the viscosity before standing and the viscosity after leaving, the rate of change was calculated using the following formula, and those having a rate of change within ± 20% were designated as ◯, and those exceeding ± 20% were marked with x. The results are shown in Table 2. These viscosities were measured under the same conditions as the above viscosity test.
(Viscosity after leaving-Viscosity before leaving) / Viscosity before leaving x 100

5. The viscosity was measured and evaluated under the same conditions as the above 10 ° C. shelf life test except that each joint reinforcing composition placed in the -10 ° C. shelf life container was left at a temperature of -10 ° C. The results are shown in Table 2.

6. Rheometer test Using a rheometer (trade name: HAKKEMARS III, manufactured by Thermo Fisher Scientific, Inc.), each joint reinforcing composition was placed in an accessory container, and the viscosity at the temperature at which the viscosity increase started and the viscosity at 180 ° C. were measured. did. The results are shown in Table 2. Further, a graph of the viscosity measured for Example 1 and Comparative Example 2 is shown in FIG. The viscosity was measured by heating from room temperature to 300 ° C. under a temperature rising condition of 5 ° C./min to a gap of 0.50 mm and a frequency of 1 Hz. The temperature at which the viscosity increase starts refers to the temperature at which the viscosity starts to increase when the viscosity exceeds 1,000 Pa · s without a significant decrease in viscosity.

As described above, the bonding reinforcing composition of this example can realize a good shelf life and a good viscosity even when left at temperatures of 10 ° C. and -10 ° C. without selecting an activator to be used. At the same time, good meltability can be imparted to the solder balls forming the joint portion, and as a result, good joint reliability can be ensured.
Further, the bonding reinforcing composition of this example has a low viscosity of 0.1 to 10 Pa · s at 180 ° C. under the above conditions, and a high temperature of 160 ° C. or higher at which the temperature rises significantly. Therefore, a good viscosity can be realized even when the joint reinforcing portion is formed by using this.
Therefore, an electronic circuit board having a joint reinforcing portion formed of such a joint reinforcing composition can be suitably used for an electronic device that requires higher reliability, such as an automobile electronic device.

Claims (6)

It contains (A) a thermosetting resin, (B) an activator, and (C) a curing agent.
The thermosetting resin (A) contains a maleimide compound (A-1) having a maleimide skeleton.
The blending amount of the activator (B) is 3% by weight to 50% by weight with respect to the total solid content of the solder joint reinforcing composition.
The solder joint reinforcing composition, wherein the curing agent (C) is at least one selected from an imidazole compound, an imidazole salt, a melamine, and an amine. The composition for reinforcing a solder joint according to claim 1, wherein the maleimide compound (A-1) has a plurality of maleimide groups at the terminal or side chain. The solder joint reinforcing according to claim 1 or 2, wherein the maleimide compound (A-1) contains at least one of the maleimide compounds represented by the following general formulas (1) and (2). Composition.
(In the formula, Y represents a dimer diamine residue or an aliphatic diamine residue derived from a polymerized fatty acid having 36 or 54 carbon atoms.
Z represents an imide compound residue consisting of the reaction of tetracarboxylic acid dianhydride and a primary amine,
P represents an integer from 0 to 10. )
(Wherein, _{R 8 R 1} to Represents hydrogen, hydroxyl, either a methyl group or an ethyl group,
X represents any organic group that has no intervening organic group or consists of C, H, O. ) The composition for reinforcing solder joints according to any one of claims 1 to 3, wherein the maleimide compound (A-1) contains a polyfunctional aromatic maleimide compound and a polyfunctional aliphatic maleimide compound. Stuff. The blending ratio of the polyfunctional aromatic maleimide compound to the polyfunctional aliphatic maleimide compound is characterized by a weight ratio of 5:95 to 95: 5 (polyfunctional aromatic maleimide compound: polyfunctional aliphatic maleimide compound). The composition for reinforcing a solder joint according to claim 4. It is a method of manufacturing a joint reinforcing portion that reinforces the bonding between a substrate and a material to be bonded to be bonded on the substrate.
A step of providing a metal for joining at at least one predetermined position on the substrate and the material to be joined.
A step of applying the solder joint reinforcing composition according to any one of claims 1 to 5 to a predetermined position of the substrate or the material to be joined.
A step of placing the material to be joined in a predetermined position on the substrate and heating the material,
The metal for joining is melted by heating to form a joining portion for joining the substrate and the material to be joined, and a cured product of the composition for reinforcing solder joining is formed in at least one of a region abutting the joining portion and a region in the vicinity thereof. A method for manufacturing a joint reinforcing portion, which comprises a step of forming a joint reinforcing portion comprising the above.