JP5463328B2 - Method for joining package parts and thermosetting resin composition used in the method - Google Patents

Description

  The present invention relates to a method for joining package parts having solder balls and a thermosetting resin composition used in the method.

As electronic devices become smaller and thinner, package parts having solder balls (so-called ball grid array package: BGA package) are used. Further, such a BGA package is also required to have a fine pitch. However, when a fine pitch BGA package is joined to a mounting substrate, there is a problem that the strength of the joint portion is weak only with solder balls. For this reason, usually, the joint portion is reinforced by filling and curing an underfill material between the BGA package and the mounting substrate. However, since it takes time to fill and cure the underfill material, there is a problem in terms of production cost.
On the other hand, a method has been proposed in which an adhesive containing a flux agent is printed in advance on a mounting substrate, and a package component is mounted on a printed portion (see Patent Document 1).

JP-A-4-280443

However, the method using an adhesive described in Patent Document 1 also has a problem in terms of production cost because it requires a separate printing process for the adhesive, which takes time and requires special equipment.
Accordingly, the present invention provides a bonding method for package components capable of ensuring the bonding strength between a package component having solder balls and a mounting substrate by a simple method, and a thermosetting resin composition used in the method. The purpose is to do.

In order to solve the above-described problems, the present invention provides the following method for joining package parts and a thermosetting resin composition used in the method.
That is, the bonding method of the package component of the present invention is a bonding method of a package component in which a package component having solder balls is bonded to a mounting substrate, which is made of a thermosetting resin composition, and the thickness is the height of the solder ball A film forming step of forming a resin composition film that is 20% or more and 90% or less with respect to the dimensions, and a solder ball of the package component is immersed in the resin composition film, whereby the thermosetting resin composition is A resin composition attaching step to be attached to the solder balls; a mounting step in which the package component to which the thermosetting resin composition is attached is mounted on a bonding land of the mounting substrate; and a mounting substrate on which the package component is mounted A reflow step of melting the solder balls by heating the solder balls and bonding the solder balls to the bonding lands of the mounting substrate. , The thermosetting resin composition, a thickness of the tack force at 2N / ^{m 2} or more 14N / ^{m 2} or less in the case of forming a film of 0.2 mm, a viscosity of 20 Pa · s or more at a temperature 40 ° C. 3000 Pa · s or less, the minimum viscosity is 1 Pa · s or less when the temperature is raised from a temperature of 40 ° C. to the melting point of the solder at a rate of 0.1 ° C./second, and 0 from the temperature of 40 ° C. to the melting point of the solder The method is characterized in that the viscosity at the melting point of the solder after being heated at a temperature rising rate of 1 ° C./second is 10,000 Pa · s or more .
In the method for bonding package parts according to the present invention, it is preferable that a solder paste printing step of printing a solder paste on a bonding land of the mounting board is further provided before the mounting step.

The thermosetting resin composition of the present invention is a thermosetting resin composition used in the method for bonding package parts, and has a tack force of 2 N / m ² or more and 14 N when a film having a thickness of 0.2 mm is formed. / M ² or less, the viscosity at a temperature of 40 ° C. is from 100 Pa · s to 3000 Pa · s, and the minimum viscosity when the temperature is raised from the temperature of 40 ° C. to the melting point of the solder at a heating rate of 0.1 ° C./second. Is 1 Pa · s or less, and the viscosity at the melting point of the solder after being heated from the temperature of 40 ° C. to the melting point of the solder at a temperature rising rate of 0.1 ° C./second is 10000 Pa · s or more. Is.
In addition, the other thermosetting resin composition of the present invention has a tack force of 2 N / m ² or more and 14 N / m ² or less when a film having a thickness of 0.2 mm is formed, and a viscosity at a temperature of 40 ° C. is 20 Pa. S to 100 Pa · s, the minimum viscosity is 1 Pa · s or less when the temperature is raised from a temperature of 40 ° C. to the melting point of the solder at a temperature rising rate of 0.1 ° C./second, and from a temperature of 40 ° C. The viscosity at the melting point of the solder after being heated up to the melting point of the solder at a heating rate of 0.1 ° C./second is 10000 Pa · s or more.
The thermosetting resin composition of the present invention needs to contain an epoxy resin, an organic acid, and a thixotropic agent.
Moreover, it is preferable that the thermosetting resin composition of this invention further contains a monofunctional glycidyl group containing compound.

In the method for bonding package components of the present invention, as described below, it is possible to secure the bonding strength between the package component having solder balls and the mounting substrate by a simple method.
That is, in the method for bonding package parts of the present invention, before mounting the package parts having solder balls on the mounting substrate, the solder balls of the package parts are immersed in a resin composition film having a predetermined thickness, A curable resin composition is adhered to the solder balls. By doing in this way, the said thermosetting resin composition can be made to adhere only to the solder ball of the said package component, and the adhesion amount of the said thermosetting resin composition can also be made uniform. Therefore, since there is too much adhesion amount of the thermosetting resin composition in the package component, there is no fear that the package component cannot be peeled off from the resin composition film. Since the adhesion amount of the thermosetting resin composition is too small, there is no possibility of causing a problem that the bonding strength between the package component and the mounting substrate cannot be ensured.
Moreover, in the joining method of the package components of this invention, after mounting the package components to which the said thermosetting resin composition adhered to the said mounting substrate, the reflow process is performed. Thus, using the heat in the reflow process, the thermosetting resin composition is wetted and spread on the solder balls, and after the thermosetting resin composition is wetted and spread, By curing the object, the bonding strength between the package component and the mounting substrate can be ensured.
In this manner, even when the joint portion is not reinforced using an underfill material or the like, it is possible to secure the joint strength between the package component having the solder ball and the mounting substrate by a simple method.

  According to the present invention, there is provided a method for bonding package components capable of ensuring the bonding strength between a package component having solder balls and a mounting substrate by a simple method, and a thermosetting resin composition used in the method. it can.

It is the schematic which shows the package components and resin composition film | membrane used for this invention. In this invention, it is the schematic which shows the state which immersed the solder ball of the package components in the resin composition film | membrane. In this invention, it is the schematic which shows the state before mounting the package components to which the thermosetting resin composition was made to adhere to a mounting substrate. In this invention, it is the schematic which shows the state after mounting the package component which adhered the thermosetting resin composition on the mounting board | substrate, and performing the reflow process.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a method for joining package parts of the present invention will be described with reference to the drawings. 1-4 is a figure for demonstrating the joining method of the package components of this invention.
The package component bonding method of the present invention is a package component bonding method for bonding a package component 1 having solder balls 11 to a mounting substrate 2 as shown in FIGS. , A resin composition attaching step, a mounting step, and a reflow step.
The package component 1 is a package component having solder balls 11, and has the solder balls 11 on the lands 13 on one surface of the package substrate 12. The diameter of the solder ball is not particularly limited, but is preferably 0.1 mm or more and 0.8 mm or less, and more preferably 0.2 mm or more and 0.7 mm or less. When the diameter of the solder ball is less than the lower limit, the solder ball is too small and it tends to be difficult to join the package component to the mounting substrate. Since the bonding strength between the package component and the mounting substrate can be ensured only by bonding, it is not necessary to adopt the method for bonding package components of the present invention. The pitch of the solder balls is not particularly limited, but is preferably 0.2 mm or more and 1.5 mm or less, and more preferably 0.4 mm or more and 1.3 mm or less. If the pitch of the solder balls is less than the above lower limit, it is difficult to mount the package parts, and it is difficult to control the adhesion amount of the thermosetting resin composition. On the other hand, when the above upper limit is exceeded, the bonding strength between the package component and the mounting substrate can be ensured only by bonding with the solder ball, so there is no need to adopt the method for bonding package components of the present invention. .
Although the size of the package component 1 is not particularly limited, for example, it is preferable that the length of one side of the package component 1 is 5 mm or more and 30 mm or less. Further, the number of solder balls per package component 1 is not particularly limited, but is preferably 200 or more and 1000 or less, for example.
The solder used for this invention is not specifically limited, A well-known solder can be used suitably. Also, the melting point of the solder used in the present invention is not particularly limited, but usually it is preferably 130 ° C. or higher and 250 ° C. or lower.

In the film forming step, as shown in FIG. 1, a resin composition film 3 having a thickness (T) of 20% or more and 90% or less with respect to the height dimension (H) of the solder ball is formed. If the thickness (T) of the resin composition film is less than the lower limit, the bonding strength between the package component and the mounting substrate becomes insufficient due to the insufficient amount of the thermosetting resin composition attached to the package component, If the upper limit is exceeded, the amount of the thermosetting resin composition adhering to the package component is too large, and there is a possibility that the package component cannot be peeled off from the resin composition film.
As a thermosetting resin composition used for this invention, a well-known thermosetting resin composition can be used suitably, and especially the thermosetting resin composition of this invention mentioned later can be used suitably.
The method of forming the resin composition film 3 is not particularly limited, but a method of forming the resin composition film 3 as shown in FIG. 1 by applying the thermosetting resin composition on the support 4 is adopted. can do. Examples of the coating apparatus used in such a case include a roll coater, a curtain coater, a spray coater, a dip coater, a bar coater, an applicator, a screen printer, a die coater, a lip coater, a comma coater, and a gravure coater. Among these, a roll coater and a die coater are more preferable, and a roll coater is particularly preferable from the viewpoint of film thickness uniformity and ease of application to a chip mount apparatus.

In the resin composition attaching step, as shown in FIG. 2, the solder balls 11 of the package component 1 are immersed in the resin composition film 3 to attach the thermosetting resin composition to the solder balls 11.
When the solder balls 11 of the package component 1 are immersed in the resin composition film 3, it is preferable that the solder balls 11 are in contact with the support 4. In this way, since the thickness of the resin composition film 3 is uniform, the amount of the thermosetting resin composition that adheres to the solder balls 11 can be made uniform.

In the mounting process, as shown in FIG. 3, the package component 1 to which the thermosetting resin composition is attached is mounted on the bonding land 21 of the mounting substrate 2.
The mounting substrate 2 includes an insulating base material 22 and bonding lands 21 formed on the insulating base material 22. Various components such as the package component 1 are mounted on the bonding land 21.
As a device used in the mounting process, a known chip mount device can be used as appropriate. In the present invention, it is necessary to perform a resin composition adhesion step before the mounting step. Therefore, as an apparatus used for the mounting process, it is preferable to use an apparatus that can perform the resin composition adhesion process after picking up the component and mounting it on the mounting substrate 2.
As a material of the bonding land 21, a known conductive material (such as copper or silver) can be used as appropriate. Moreover, as the insulating base material 22, a well-known insulating base material (a glass epoxy base material, a polyimide base material, etc.) can be used suitably.

In the reflow process, by heating the mounting substrate 2 on which the package component 1 is mounted, the solder balls 11 are melted, and the solder balls 11 are bonded to the bonding lands 21 of the mounting substrate as shown in FIG.
As an apparatus used for the reflow process, a known reflow furnace can be appropriately used.
The heating temperature in the reflow process is not limited because it varies depending on the melting point of the solder. For example, the heating temperature is preferably higher by 10 ° C. than the melting point of the solder, and more preferably higher by 15 ° C. than the melting point of the solder.
The temperature increase rate in the reflow process is preferably 0.2 ° C./second or more and 2.0 ° C./second or less, and more preferably 0.4 ° C./second or more and 1.8 ° C./second or less. If the heating rate is less than the lower limit, the thermosetting resin composition may be cured before the solder melts. On the other hand, if the upper limit is exceeded, the wetting and spreading of the thermosetting resin composition is insufficient. It tends to be.

According to the above embodiment, the following effects can be obtained.
That is, the thermosetting resin composition can be attached only to the solder balls 11 of the package component 1, and the adhesion amount of the thermosetting resin composition can be made uniform. Therefore, since there is too much adhesion amount of the thermosetting resin composition in the package component 1, there is no possibility that the package component 1 cannot be peeled off from the resin composition film 3, but on the other hand, the package component 1 Therefore, there is no possibility that the bonding strength between the package component 1 and the mounting substrate 2 cannot be ensured because the adhesion amount of the thermosetting resin composition is too small.
Further, as shown in FIG. 3, the heat-curable resin composition 31 after adhering to the solder balls 11 of the package component 1 is wetted and spread on the solder balls 11 by using heat in the reflow process. After the curable resin composition 31 wets and spreads, the thermosetting resin composition 31 is cured to form a cured thermosetting resin composition 32 as shown in FIG. Bonding strength with the substrate 2 can be ensured.
In this way, even when the joint portion is not reinforced using an underfill material or the like, the joint strength between the package component 1 having the solder balls 11 and the mounting substrate 2 can be secured by a simple method.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements and the like within a scope that can achieve the object of the present invention are included in the present invention.
For example, in the embodiment, a solder paste printing step of printing a solder paste (not shown) on the bonding lands 21 of the mounting substrate 2 may be performed before the mounting step. By such a printing process, the bonding strength between the package component 1 having the solder balls 11 and the mounting substrate 2 can be further improved.
As a solder paste used in such a case, a known solder paste can be used as appropriate.

Next, the thermosetting resin composition of the present invention will be described. That is, the thermosetting resin composition of the present invention is a thermosetting resin composition used in the method for bonding package parts.
In the thermosetting resin composition of the present invention, when a film having a thickness of 0.2 mm is formed, the tack force is 2 N / m ² or more and 14 N / m ² or less (preferably 4 N / m ² or more). 12 N / m ² or less). If the tack force is less than the above lower limit, when the package component is mounted on the land, the holding force temporarily decreases, so that not only is the position easily misaligned during the reflow process, but also the solder ball of the thermosetting resin composition. When the upper limit is exceeded, when the thermosetting resin composition is adhered to the package component, the package component is removed from the resin composition film. There arises a problem that it cannot be peeled off. The tack force can be measured in accordance with the method described in JIS-Z3284. Specifically, the tack force tester (manufactured by Marco, trade name “TK-1”) and the diameter is 5.1 mm. It can be measured using a test probe.

In the thermosetting resin composition of the present invention, the viscosity (rheometer viscosity) at a temperature of 40 ° C. is required to be 20 Pa · s or more and 3000 Pa · s or less. When the viscosity at a temperature of 40 ° C. is less than 20 Pa · s, the holding power is temporarily reduced when the package component is mounted on the land, so that not only is the position easily displaced during the reflow process, but the thermosetting resin composition. Insufficient bonding strength to the solder balls makes it impossible to secure a sufficient bonding strength. On the other hand, when it exceeds 3000 Pa · s, when the thermosetting resin composition is attached to the package component, The problem that it cannot peel off from a resin composition film | membrane arises. Further, from the viewpoint of handling properties of the thermosetting resin composition, the viscosity at a temperature of 40 ° C. is more preferably 500 Pa · s or more and 2000 Pa · s or less. Further, from the viewpoint of the bonding strength between the package component having solder balls and the mounting substrate, the viscosity at a temperature of 40 ° C. is more preferably 20 Pa · s to 100 Pa · s. In addition, the viscosity in this invention can be measured with a viscoelasticity measuring apparatus. Specifically, the viscosity can be measured under predetermined conditions using a rheometer (manufactured by HAAKE, trade name “MARS-III”).
In the thermosetting resin composition of the present invention, it is necessary that the minimum viscosity is 1 Pa · s or less when the temperature is increased from a temperature of 40 ° C. to the melting point of the solder at a temperature increase rate of 0.1 ° C./second. . When the minimum viscosity is higher than 1 Pa · s, wetting and spreading of the thermosetting resin composition to the solder balls becomes insufficient. Moreover, it is more preferable that the minimum viscosity is 0.1 Pa · s or more and less than 1 Pa · s from the viewpoint of spreading the thermosetting resin composition onto the solder balls.
In the thermosetting resin composition of the present invention, the viscosity at the melting point of the solder after being heated from the temperature of 40 ° C. to the melting point of the solder at a temperature rising rate of 0.1 ° C./second is 10,000 Pa · s or more. is necessary. If the viscosity is 10,000 Pa · s or more, it can be determined that the thermosetting resin composition is sufficiently cured. In addition, when measuring the viscosity at the melting point of the solder in this way, in order to stably measure the viscosity, the temperature is measured after the temperature of the thermosetting resin composition is kept constant for a predetermined time (for example, 10 minutes). May be.

In the thermosetting resin composition of the present invention, the Brookfield viscosity (BF viscosity) at a temperature of 25 ° C. is preferably 0.8 × 10 ³ mPa · s or more and 100 × 10 ³ mPa · s or less. From the viewpoint of the bonding strength between the package component having a solder ball and the mounting substrate, the BF viscosity at a temperature of 25 ° C. is more preferably 0.8 × 10 ³ mPa · s or more and 5 × 10 ³ mPa · s or less. .
Further, in the thermosetting resin composition of the present invention, the thixo ratio is not particularly limited, but is preferably 2 or more and 4.5 or less.

The thermosetting resin composition of the present invention preferably contains an epoxy resin, an organic acid, and a thixotropic agent. As described above, when the epoxy resin and the organic acid are used in combination, the reaction start temperature can be set in a range suitable for the packaging method of the present invention, so the viscosity in the thermosetting resin composition satisfies the above condition. It tends to be easy to adjust to meet. In addition, since the organic acid acts as a curing agent for the epoxy resin and also acts as a flux component for removing the oxide film on the solder surface, it is possible to improve the strength of the solder joint. Furthermore, by adjusting the content of the thixotropic agent, the viscosity of the thermosetting resin composition can be adjusted so as to satisfy the above conditions.
As an epoxy resin used for this invention, a well-known epoxy resin can be used suitably. Examples of such epoxy resins include bisphenol A type, bisphenol F type, biphenyl type, naphthalene type, cresol novolak type, phenol novolak type and the like. These epoxy resins may be used individually by 1 type, and may mix and use 2 or more types. Further, these epoxy resins preferably contain a liquid at normal temperature, and when a solid at normal temperature is used, it is preferably used in combination with a liquid at normal temperature. Of these epoxy resin molds, the cured bisphenol A type and the liquid bisphenol F are preferable from the viewpoint that the cured product is effective against drop impact and has good wettability in the reflow process up to the melting point of the solder. Type and liquid hydrogenated bisphenol A type are preferred.
As content of the said epoxy resin, it is preferable that it is 50 to 98 mass% with respect to 100 mass% of thermosetting resin compositions, and it is more preferable that it is 70 to 94 mass%. . If the content of the epoxy resin is less than the lower limit, sufficient strength for fixing the package parts cannot be obtained, and thus the resistance to drop impact tends to decrease. On the other hand, if the content exceeds the upper limit, the thermosetting resin The contents of the organic acid and the thixotropic agent in the composition are reduced, and the rate at which the epoxy resin is cured is delayed. At the same time, in the reflow process, the package parts are liable to be displaced and tend to have poor conduction.

The thermosetting resin composition of the present invention preferably further contains a monofunctional glycidyl group-containing compound. In the thermosetting resin composition of the present invention, by replacing a part of the epoxy resin with such a monofunctional glycidyl group-containing compound, various properties such as curability of the thermosetting resin composition are maintained. Meanwhile, the viscosity of the thermosetting resin composition can be adjusted to a more suitable range.
As the monofunctional glycidyl group-containing compound used in the present invention, a known monofunctional glycidyl group-containing compound can be appropriately used. Examples of such monofunctional glycidyl group-containing compounds include methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, 2- Methyl octyl glycidyl ether, methoxy polyethylene glycol monoglycidyl ether, ethoxy polyethylene glycol monoglycidyl ether, butoxy polyethylene glycol monoglycidyl ether, phenoxy polyethylene glycol monoglycidyl ether, p-tertiary butyl phenyl glycidyl ether, sec-butyl phenyl glycidyl ether, n -Butylphenyl glycidyl ether Phenylphenol glycidyl ether, cresyl glycidyl ether, dibromo cresyl glycidyl ether. These monofunctional glycidyl group-containing compounds may be used singly or in combination of two or more. Among these monofunctional glycidyl group-containing compounds, phenyl glycidyl ether is particularly preferable from the viewpoint of easy viscosity adjustment.
When the monofunctional glycidyl group-containing compound is used, the content thereof is preferably 5% by mass or more and 40% by mass or less, and preferably 10% by mass or more and 30% by mass with respect to 100% by mass of the thermosetting resin composition. % Or less is more preferable. If the content of the monofunctional glycidyl group-containing compound is less than the lower limit, the effect of adjusting the viscosity of the thermosetting resin composition tends to be difficult to obtain. On the other hand, if the content exceeds the upper limit, the thermosetting resin composition There is a tendency that various properties such as curability of the resin deteriorate.

As the organic acid used in the present invention, a known organic acid can be appropriately used. Among these organic acids, it is preferable to use a dibasic acid having an alkylene group from the viewpoint of excellent solubility with an epoxy resin and from the viewpoint that crystals are hardly precipitated during storage. Examples of the dibasic acid having such an alkylene group include adipic acid, 2,5-diethyladipic acid, 2,4-diethylglutaric acid, 2,2-diethylglutaric acid, 3-methylglutaric acid, 2- Examples include ethyl-3-propylglutaric acid and sebacic acid. Among these, adipic acid is preferable.
As content of the said organic acid, it is preferable that they are 1 mass% or more and 25 mass% or less with respect to 100 mass% of thermosetting resin compositions, and it is more preferable that they are 5 mass% or more and 20 mass% or less. . If the content of the organic acid is less than the lower limit, the curing rate tends to be poor due to a delay in the speed of curing the epoxy resin, while if the upper limit is exceeded, the thermosetting resin composition is cured. The insulation reliability of the film tends to decrease.

As the thixotropic agent used in the present invention, a known thixotropic agent can be appropriately used. Examples of such a thixotropic agent include fatty acid amide and hydrogenated castor oil. Among these, fatty acid amide is preferable from the viewpoint of adhesion when the thermosetting resin composition is adhered to the solder balls of the package component and the component is mounted on the bonding land.
The thixotropic agent content is preferably 0.5% by mass or more and 10% by mass or less, and preferably 1% by mass or more and 5% by mass or less with respect to 100% by mass of the thermosetting resin composition. More preferred. If the content of the thixotropic agent is less than the above lower limit, thixotropy cannot be obtained, and when the solder balls of the package parts are immersed in the resin composition film, the thermosetting resin composition does not adhere sufficiently, and on the bonding land. On the other hand, when the upper limit is exceeded, the insulation reliability of the cured film that makes it difficult for the thermosetting resin composition to wet and spread on the solder balls tends to decrease. It is in.

  The thermosetting resin composition of the present invention, if necessary, in addition to the epoxy resin, the organic acid and the thixotropic agent, an epoxy resin curing agent, a surfactant, a coupling agent, an antifoaming agent, a powder surface treatment An additive such as an agent, a reaction inhibitor, and an anti-settling agent may be contained. The content of these additives is preferably 0.01% by mass or more and 10% by mass or less, and 0.05% by mass or more and 5% by mass or less with respect to 100% by mass of the thermosetting resin composition. More preferably. If the content of the additive is less than the lower limit, the effect of each additive tends to be difficult to achieve. On the other hand, if the content exceeds the upper limit, the bonding strength due to the thermosetting resin composition tends to decrease.

EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these examples.
[Example 1]
Epoxy resin A (bisphenol A type epoxy resin, manufactured by DIC, trade name “EPICLON 860”) 91% by mass, thixotropic agent (fatty acid amide, Nippon Kasei Co., Ltd., trade name “Sripacks E”) 2% by weight, organic acid ( 5% by mass of adipic acid (manufactured by Kanto Denka Kogyo Co., Ltd.), 1% by mass of a surfactant (manufactured by BYK Japan Japan, trade name “BYK361N”) and an antifoaming agent (trade name “Floren AC-303”, manufactured by Kyoeisha Chemical Co., Ltd.) ) 1% by mass was put into a container and mixed using a rough machine to obtain a thermosetting resin composition. And the obtained thermosetting resin composition was apply | coated with the applicator (for 100 micrometers) on a support body, and the resin composition film | membrane was obtained. The thickness of the obtained resin composition film was 0.09 mm.
Next, a BGA package (size: 17 mm × 17 mm, solder ball height: 0.3 mm, solder ball pitch: 0.5 mm) using a chip mount device (manufactured by YAMAHA, trade name “YV100Xg-F”) , Solder melting point: 217 ° C., solder composition: 96.5Sn / 3Ag / 0.5Cu), and a BGA package solder ball is immersed in the obtained resin composition film to obtain a thermosetting resin composition Objects were attached to the solder balls. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 30%. Thereafter, the BGA package to which the thermosetting resin composition was adhered was mounted on the bonding land of the mounting substrate.
Next, the mounting board on which the BGA package is mounted is heated to a temperature of 240 ° C. in a reflow furnace (trade name “TNP” manufactured by Tamura Corporation) to melt the solder balls and join the BGA package and the mounting board. .
[Example 2]
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the thickness of the resin composition film was 0.27 mm. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 90%.

[Example 3]
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the thickness of the resin composition film was 0.18 mm. The ratio of the thickness of the resin composition film to the solder ball height of 100% is 60%.
[Example 4]
As a mounting substrate, a solder paste TLF-204 (solder composition: Sn / 3.0Au / 0.5Cu, manufactured by Tamura Seisakusho Co., Ltd.) having a thickness of 0.15 mm is previously printed on a connection land of the mounting substrate. The BGA package and the mounting substrate were bonded in the same manner as in Example 3 except that they were used. The ratio of the thickness of the resin composition film to the solder ball height of 100% is 60%.
[Examples 5 to 7]
A thermosetting resin composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 1. And the obtained thermosetting resin composition was apply | coated with the applicator (for 200 micrometers) on a support body, and the resin composition film | membrane was obtained. The thickness of the obtained resin composition film was 0.18 mm.
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the resin composition film obtained as described above was used instead of the resin composition film used in Example 1. The ratio of the thickness of the resin composition film to the solder ball height of 100% is 60%.

[Comparative Example 1]
Except that the thickness of the resin composition film was 0.36 mm, an attempt was made to join the BGA package and the mounting substrate in the same manner as in Example 1. However, the BGA package could not be peeled from the resin composition film after the solder balls of the BGA package were immersed in the resin composition film. Note that the ratio of the thickness of the resin composition film to the height dimension of the solder ball of 100% is more than 100%.
[Comparative Example 2]
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the thickness of the resin composition film was 0.03 mm. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 10%.

[Comparative Example 3]
Rosin resin (Harima Kasei Co., Ltd., trade name “Hariphenol 512”) 60 mass%, thixotropic agent (fatty acid amide, Nihon Kasei Co., Ltd., trade name “Sripacks E” 3 mass%, organic acid (adipic acid, Kanto Denka) 10% by mass, manufactured by Kogyo Co., Ltd., trade name “BYK361N”, and 1% by mass of an antifoaming agent (trade name “Floren AC-303”, manufactured by Kyoeisha Chemical Co., Ltd.) An organic solvent (hexyl diglycol) 25% by mass was put into a container and mixed using a raking machine to obtain a flux resin composition, and the obtained flux resin composition was applied to a support on an applicator (300 μm). The resin composition film thus obtained was 0.27 mm in thickness.
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the resin composition film obtained as described above was used instead of the resin composition film used in Example 1. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 90%.
[Comparative Example 4]
Other than using a solder paste (solder composition: Sn / 3.0Au / 0.5Cu, manufactured by Tamura Seisakusho Co., Ltd.) having a thickness of 0.15 mm in advance on the connection land of the mounting board as the mounting board. In the same manner as in Comparative Example 3, the BGA package and the mounting substrate were joined. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 90%.

[Reference Example 1]
A thermosetting resin composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 2. And the obtained thermosetting resin composition was apply | coated with the applicator (for 100 micrometers) on a support body, and the resin composition film | membrane was obtained. The thickness of the obtained resin composition film was 0.09 mm.
An attempt was made to join the BGA package and the mounting substrate in the same manner as in Example 1 except that the resin composition film obtained as described above was used instead of the resin composition film used in Example 1. However, the BGA package could not be peeled from the resin composition film after the solder balls of the BGA package were immersed in the resin composition film. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 30%.
[Reference Examples 2 to 4]
A thermosetting resin composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 2. And the obtained thermosetting resin composition was apply | coated with the applicator (for 100 micrometers) on a support body, and the resin composition film | membrane was obtained. The thickness of the obtained resin composition film was 0.09 mm.
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the resin composition film obtained as described above was used instead of the resin composition film used in Example 1. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 30%.

<Evaluation of joining method of resin composition and package parts>
Resin composition performance (tack force, rheometer viscosity, BF viscosity, thixo ratio), workability when mounting package components, and performance of joints between package components and mounting substrate (resistance value, number of drop impacts) Was evaluated or measured by the following method. The obtained results are shown in Tables 1 and 2. In Comparative Example 1 and Reference Example 1, since the BGA package could not be peeled from the resin composition film, the performance of the joint portion between the package component and the mounting substrate could not be measured.
(I) Tack force Tack force tester (manufactured by Marco, trade name “TK-1”) and a test probe having a diameter of 5.1 mm are used and a resin composition film (thickness: 0.2 mm) according to JISZ3284. ) Tack force was measured.
(Ii) Rheometer viscosity Resin while increasing the temperature from a temperature of 40 ° C. to the melting point of the solder at a temperature increase rate of 0.1 ° C./second using a rheometer (manufactured by HAAKE, trade name “MARS-III”) The viscosity of the composition was measured. From the obtained results, the viscosity at a temperature of 40 ° C., the minimum viscosity when the temperature is raised from the temperature of 40 ° C. to the melting point of the solder at a temperature rising rate of 0.1 ° C./second, and the viscosity at the melting point of the solder after the temperature rise. Asked.
(Iii) Brookfield viscosity (BF viscosity)
Using a viscometer RVT type manufactured by Brookfield, the BF viscosity of the resin composition at a temperature of 25 ° C. was measured at a spindle rotation speed of 50 rpm.
(Iv) Thixo ratio Using a viscometer RVT type manufactured by Brookfield, the BF viscosity (η5) of the resin composition at a spindle rotation speed of 5 rpm and a temperature of 25 ° C., and the resin composition at a spindle rotation speed of 50 rpm and a temperature of 25 ° C. The BF viscosity (η50) of each product was measured. And thixo ratio ((eta) 5 / (eta) 50) was computed from these measured values.
(V) Workability at the time of mounting the package component After the chip components (made by YAMAHA, trade name “YV100Xg-F”) are used to immerse the solder balls of the package component in the resin composition film, the resin composition It was evaluated whether it was possible to remove the package component from the material film. When the package part could be peeled from the resin composition film, it was determined as “pass”, and when the package part could not be peeled from the resin composition film, it was determined as “fail”.
(Vi) Resistance Value Using a digital multimeter (manufactured by Agilent, trade name “34401A”), the resistance value at the joint between the package component and the mounting substrate was measured. In addition, about the thing whose resistance value became 1000 MΩ or more, it was determined as “impossible to measure”.
(Vii) Number of drop impacts The number of drop impacts was measured as follows using a sample obtained by bonding a package component to a mounting substrate. That is, a sample was fixed to a jig, a conductive wiring (for resistance value measurement) was connected, and an initial resistance value was measured using a digital multimeter (manufactured by Agilent, trade name “34401A”). And the operation | work of dropping the sample from 100 cm in height and measuring the resistance value while giving an impact was repeated. The number of times until the resistance value during dropping became four times the initial resistance value was defined as the number of drop impacts. Further, those having a resistance value of 1000 MΩ or more were determined as “impossible to measure”.

  As is apparent from the results shown in Tables 1 and 2, according to the method for joining package parts (Examples 1 to 5) of the present invention, the package part having the solder balls and the mounting substrate can be formed by a simple method. It was confirmed that the bonding strength was secured. On the other hand, when the ratio of the thickness of the resin composition film to 100% of the solder ball height is 10% or 100% (Comparative Examples 1 and 2), and the flux resin composition having no thermosetting property When used (Comparative Examples 3 to 4), it was confirmed that the bonding strength between the package component having solder balls and the mounting substrate could not be ensured. Further, when the tack force and viscosity of the thermoplastic resin composition do not satisfy the conditions as the thermoplastic resin composition of the present invention (Reference Examples 1 to 4), the bonding between the package component having solder balls and the mounting substrate is performed. It was confirmed that the strength could not be secured. In Reference Example 2 and Reference Example 4, since the fluidity of the thermoplastic resin composition is insufficient in the reflow process, a resin film is interposed between the solder and the land surface, resulting in poor conduction. As a result, the resistance value is assumed to be 1000 MΩ or more.

[Example 8]
Epoxy resin A (bisphenol A type epoxy resin, manufactured by DIC, trade name “EPICLON 860”) 52 mass%, epoxy resin B (biphenylaralkyl type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., trade name “NC-3000”) 11 .3% by mass, monofunctional glycidyl group-containing compound (phenylglycidyl ether, manufactured by Nagase ChemteX Corporation, trade name “Denacol EX-141”), thixotropic agent (fatty acid amide, manufactured by Nippon Kasei Chemical Co., Ltd., trade name “Sripacs” E ") 0.5% by mass, organic acid (adipic acid, manufactured by Kanto Denka Kogyo Co., Ltd.) 4.2% by mass, surfactant (manufactured by BYK Japan Japan, trade name" BYK361N ") 1% by mass and antifoaming agent (Made by Kyoeisha Chemical Co., Ltd., trade name “Floren AC-303”) 1% by mass is charged into a container and mixed using a rake machine to heat cure. To obtain a resin composition. And the obtained thermosetting resin composition was apply | coated with the applicator so that it might become thickness shown in Table 3 on the support body, and the resin composition film | membrane was obtained.
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the resin composition film obtained as described above was used instead of the resin composition film used in Example 1. The ratio of the thickness of the resin composition film to the solder ball height dimension of 100% is 67%.

[Examples 9 to 12]
A thermosetting resin composition was obtained in the same manner as in Example 1 except that each material was blended according to the composition shown in Table 3. And the obtained thermosetting resin composition was apply | coated with various applicators so that it might become thickness shown in Table 3 on the support body, and the resin composition film | membrane was obtained.
The BGA package and the mounting substrate were joined in the same manner as in Example 1 except that the resin composition film obtained as described above was used instead of the resin composition film used in Example 1. The ratio of the thickness of the resin composition film to the solder ball height of 100% is 67% (Examples 9 and 10), 50% (Example 11), and 90% (Example 12), respectively.

<Evaluation of joining method of thermosetting resin composition and package parts>
Performance of thermosetting resin composition (tack force, viscosity, BF viscosity, thixo ratio), workability when mounting package parts, and performance of joint part between package parts and mounting substrate (resistance value, number of drop impacts) ) Was evaluated or measured by the above method. The obtained results are shown in Table 3.

  As is apparent from the results shown in Table 3, when the rheometer viscosity at a temperature of 40 ° C. is 30 to 100 Pa · s (Examples 8 to 12), the number of drop impacts increases, and the package component having solder balls It was confirmed that the bonding strength between the substrate and the mounting substrate could be further improved. In Examples 8 to 12, the BF viscosity at a temperature of 25 ° C. is also low in the range of 900 to 4800 mPa · s, and the fluidity is high. It is presumed that the bonding strength between the component and the mounting board is improved.

  The method for bonding package components of the present invention can be suitably used for a vehicle-mounted substrate or the like that particularly requires a bonding strength between a package component having solder balls and a mounting substrate.

DESCRIPTION OF SYMBOLS 1 ... Package component 11 ... Solder ball 12 ... Package board 13 ... Land 2 ... Mounting board 21 ... Bonding land 22 ... Insulating base material 3 ... Resin composition film 31 ... Thermosetting resin composition after adhesion 32 ... After hardening Thermosetting resin composition 4 ... Support

Claims (5)

A package component joining method for joining a package component having a solder ball to a mounting substrate,
A film forming step of forming a resin composition film comprising a thermosetting resin composition and having a thickness of 20% or more and 90% or less with respect to the height dimension of the solder ball;
A resin composition attaching step of immersing the solder balls of the package component in the resin composition film and attaching the thermosetting resin composition to the solder balls;
A mounting step of mounting the package component to which the thermosetting resin composition is attached on a bonding land of the mounting substrate;
A reflow step of melting the solder ball by heating the mounting substrate on which the package component is mounted, and bonding the solder ball to a bonding land of the mounting substrate;
With
The thermosetting resin composition is
When a film having a thickness of 0.2 mm is formed, the tack force is 2 N / m ² or more and 14 N / m ² or less,
The viscosity at a temperature of 40 ° C. is 20 Pa · s or more and 3000 Pa · s or less,
When the temperature is raised from a temperature of 40 ° C. to the melting point of the solder at a rate of temperature rise of 0.1 ° C./second, the minimum viscosity is 1 Pa · s or less, and
A method for joining package parts, characterized in that the viscosity at the melting point of the solder after the temperature is raised from a temperature of 40 ° C. to the melting point of the solder at a rate of 0.1 ° C./second is 10,000 Pa · s or more. The method of joining package parts according to claim 1,
Prior to the mounting step, the method further includes a solder paste printing step of printing a solder paste on the bonding lands of the mounting substrate. A packaging component joining method for joining a package component having a solder ball to a mounting substrate, comprising a thermosetting resin composition, wherein the thickness is 20% or more and 90% or less with respect to the height dimension of the solder ball. A film forming step of forming a resin composition film, and a resin composition attachment step of immersing the solder balls of the package component in the resin composition film to attach the thermosetting resin composition to the solder balls; A mounting step of mounting the package component to which the thermosetting resin composition is adhered on the bonding land of the mounting substrate; and heating the mounting substrate on which the package component is mounted to melt the solder balls. A reflow step of bonding the solder balls to the bonding lands of the mounting substrate, and a thermosetting resin used in a method for bonding package parts. A composition,
The thermosetting resin composition contains an epoxy resin, an organic acid, and a thixotropic agent.
When a film having a thickness of 0.2 mm is formed, the tack force is 2 N / m ² or more and 14 N / m ² or less,
The viscosity at a temperature of 40 ° C. is 100 Pa · s to 3000 Pa · s,
When the temperature is raised from a temperature of 40 ° C. to the melting point of the solder at a rate of temperature rise of 0.1 ° C./second, the minimum viscosity is 1 Pa · s or less, and
A thermosetting resin composition having a viscosity at a melting point of solder of 10,000 Pa · s or more after being heated from a temperature of 40 ° C. to a melting point of the solder at a heating rate of 0.1 ° C./second. A packaging component joining method for joining a package component having a solder ball to a mounting substrate, comprising a thermosetting resin composition, wherein the thickness is 20% or more and 90% or less with respect to the height dimension of the solder ball. A film forming step of forming a resin composition film, and a resin composition attachment step of immersing the solder balls of the package component in the resin composition film to attach the thermosetting resin composition to the solder balls; A mounting step of mounting the package component to which the thermosetting resin composition is adhered on the bonding land of the mounting substrate; and heating the mounting substrate on which the package component is mounted to melt the solder balls. A reflow step of bonding the solder balls to the bonding lands of the mounting substrate, and a thermosetting resin used in a method for bonding package parts. A composition,
The thermosetting resin composition contains an epoxy resin, an organic acid, and a thixotropic agent.
When a film having a thickness of 0.2 mm is formed, the tack force is 2 N / m ² or more and 14 N / m ² or less,
The viscosity at a temperature of 40 ° C. is 20 Pa · s or more and 100 Pa · s or less,
When the temperature is raised from a temperature of 40 ° C. to the melting point of the solder at a rate of temperature rise of 0.1 ° C./second, the minimum viscosity is 1 Pa · s or less, and
A thermosetting resin composition having a viscosity at a melting point of solder of 10,000 Pa · s or more after being heated from a temperature of 40 ° C. to a melting point of the solder at a heating rate of 0.1 ° C./second. In the thermosetting resin composition according to claim 3 or 4 ,
A thermosetting resin composition further comprising a monofunctional glycidyl group-containing compound.

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