JP3255796B2 - Semiconductor device mounting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a semiconductor device, and more particularly to an improvement in a technique for mounting a semiconductor device face down using a conductive adhesive.

[0002]

2. Description of the Related Art Conventionally, as a method of mounting a semiconductor device on a circuit board by face-down, a projecting contact made of a solder alloy is previously formed on an electrode pad of the semiconductor device by a plating technique, and this projecting contact is formed. Although a method of soldering to a connection electrode of a circuit board has been used, in recent years, a method of connecting a semiconductor device to a circuit board using a conductive adhesive has been used.

As a method of mounting a semiconductor device using such a conductive adhesive, for example, US Pat. No. 4,661,192.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, there is a technique for simply connecting a semiconductor device to a circuit board by face down using a conductive adhesive. Hereinafter, a conventional mounting technique of a semiconductor device will be described with reference to the drawings.

FIG. 3 is a view showing a part of a mounting process of a semiconductor device and showing a process of transferring a conductive adhesive to a projecting contact of the semiconductor device. FIG. 4 is a cross-sectional view of a main part of a semiconductor device mounted body formed by the above-described steps.

3 and 4, reference numeral 9 denotes a semiconductor device, 10 denotes a terminal electrode formed on a predetermined portion of the semiconductor device 9, 11 denotes a projecting contact formed on the terminal electrode 10,
12 is a coating film formed by applying a conductive epoxy resin, 13 is a support base, 14 is a circuit board, 15 is a connection electrode on the circuit board 14, and 16 is a conductive epoxy resin transferred to the projecting contact 10. This is the transfer unit.

An outline of a conventional method for mounting a semiconductor device using a conductive adhesive configured as described above will be described below.

First, a coating film 10 of a conductive epoxy resin is formed on a support base 13, and as shown in FIG.
1 is lowered, and both are brought into contact with each other.
Then, the tip of the projecting contact 11 of the semiconductor device 9 is brought into contact with the conductive epoxy resin coating film 12 formed on the support base 13, thereby transferring the conductive epoxy resin to the projecting contact 11.

After that, the semiconductor device 9 having the transfer portion 16 of the conductive epoxy resin adhered on the protruding contact 11 is positioned and mounted on the connection electrode 15 on the circuit board 14, and then the conductive epoxy resin is cured. Thereby, as shown in FIG. 4, a package of the semiconductor device 9 using the conductive epoxy resin is obtained.

[0009]

However, in the above-described method for mounting a semiconductor device, since the conductive epoxy resin is used as the conductive adhesive, the semiconductor device 9 is not used.
The time required for curing the conductive epoxy resin after mounting on the circuit board 14 is long, and there is a problem that the productivity of the mounted body of the semiconductor device 9 is lacking. That is, in general, the curing of the conductive epoxy resin requires about 150 ° C. heat and one hour or more.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor device mounting method capable of easily mounting a semiconductor device on a circuit board with good productivity. It is in.

[0011]

Means for Solving the Problems In order to achieve the above object, a solution taken by the present invention is to use a thermoplastic conductive adhesive as a resin constituting the conductive adhesive.

More specifically, the means adopted in the first aspect of the present invention is a method for mounting a semiconductor device having a projecting contact face-down on a circuit board by using a conductive adhesive in a face-down manner. Forming a coating film of a conductive adhesive on the support base; and heating the conductive adhesive on the support base to maintain the plastic state in a plastic state, thereby connecting the projecting contact of the semiconductor device to the conductive base on the support base. A step of transferring the thermoplastic conductive adhesive to the protruding contact by contacting the coating with the conductive adhesive, and maintaining the transfer portion of the conductive adhesive formed in the above step in a plastic state. A step of contacting the protruding contact with the connection electrode of the circuit board; and a step of cooling the conductive adhesive while the protruding contact of the semiconductor device is in contact with the connection electrode of the circuit board, and bonding the two. It is a method.

Means taken by the invention of claim 2 is claim 1
In the invention, the step of transferring the conductive adhesive to the projecting contact of the semiconductor device is a method of heating the semiconductor device to a temperature equal to or higher than a temperature at which the conductive adhesive becomes a plastic state.

[0014] The measures taken by the invention of claim 3 correspond to claim 1.
Alternatively, in the second aspect, the step of contacting the projecting contact of the semiconductor device with the connection electrode of the circuit board is a method of heating the semiconductor device to a temperature equal to or higher than a temperature at which the conductive adhesive becomes a plastic state.

[0015] The means adopted by the invention of claim 4 corresponds to claim 1.
Alternatively, in the second aspect, the step of contacting the projecting contact of the semiconductor device with the connection electrode of the circuit board is a method of heating the circuit board to a temperature equal to or higher than a temperature at which the conductive adhesive becomes a plastic state.

According to a fifth aspect of the present invention, there is provided a method according to the first, second, third or fourth aspect, wherein the conductive adhesive contains at least a thermoplastic resin and a conductive filler.

According to a sixth aspect of the present invention, there is provided a method as set forth in the first, second, third, fourth or fifth aspect of the present invention, wherein the projecting contact of the semiconductor device has a two-step projecting shape.

[0018]

According to the above method, in the first aspect of the present invention, the conductive adhesive transferred to the protruding contact of the semiconductor device is used.
The projecting contact of the semiconductor device and the connection electrode of the circuit board are fixed. At this time, since the conductive adhesive is made of a thermoplastic resin, the conductive adhesive is hardened only by cooling, and both are bonded. Therefore, unlike the thermosetting resin, it does not require a long time for curing by the reaction, and the time required for the process is reduced. Moreover, in order to maintain the thermoplastic resin in a plasticized state, it is not necessary to maintain the thermoplastic resin at a temperature as high as when the thermosetting resin is cured. The stress is also extremely small, and the reliability of the mounted semiconductor device is improved.

According to the second aspect of the present invention, when the conductive adhesive is transferred to the protruding contact of the semiconductor device, the protruding contact is heated to a temperature higher than a temperature at which the semiconductor device becomes plastic, so that the protruding contact is made of thermoplastic conductive adhesive. The temperature is maintained at a temperature at which the agent can be transferred, and the transfer is performed smoothly.

According to the third or fourth aspect of the present invention, when the projecting contact of the semiconductor device is brought into contact with the connection electrode of the circuit board, the semiconductor device or the circuit board is heated to a thermoplastic temperature or higher, so that the thermoplastic conductive material is heated. The conductive adhesive is maintained in a plastic state, and the adhesive also adheres to the connection electrode side. At this time, heating can be performed using a tool for holding the semiconductor device or a support member for the circuit board, and the configuration of the device is simplified.

According to the fifth aspect of the present invention, the function of the conductive adhesive is easily ensured by the thermoplastic resin and the conductive filler.

According to the sixth aspect of the present invention, since the projecting contact has a two-step projecting shape, cooling of the thermoplastic conductive adhesive can be completed in a shorter time.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a mounting process of a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings.

1A to 1C are process diagrams for explaining a method of mounting a semiconductor device in an embodiment, and FIG. 2 is a cross-sectional view of a main part of a mounted body of the semiconductor device manufactured by the mounting method of FIG. It is.

In FIGS. 1 and 2, 1 is a coating film of a thermoplastic conductive adhesive in a plastic state, 2 is a heated support base, 3 is a semiconductor device, and 4 is formed on a terminal electrode of the semiconductor device. 5 is a heating / suction tool for heating and sucking the semiconductor device 3, 6 is a circuit board, 7 is a connection electrode on the circuit board 6, and 8 is a transfer portion of a thermoplastic conductive adhesive. It is. Here, the thermoplastic conductive adhesive 1 is a thermoplastic resin such as a polyester resin containing a conductive filler such as Ag.

A method of mounting the semiconductor device configured as described above and a mounted body thereof will be described below with reference to the drawings.

First, as shown in FIG. 1A, a coating film 1 made of a plasticized thermoplastic conductive adhesive is formed on a support base 2. At this time, the support base 2 is heated to a temperature equal to or higher than the temperature at which the thermoplastic conductive adhesive becomes a plastic state.

Then, as shown in FIG. 1B, while the semiconductor device 3 having the projecting contacts 4 is attracted by the heating / suction tool 5, the projecting contacts 4 are coated with the conductive adhesive coating film 1 in a plastic state. Contact. At this time, the semiconductor device 3 is heated by the heating and suction tool 2 to a temperature equal to or higher than a temperature at which the conductive adhesive becomes a plastic state. Thereafter, when the semiconductor device 3 is pulled up by the heating and suction tool 5, a part of the thermoplastic conductive adhesive is transferred onto the projecting contact 4,
The transfer section 8 is formed.

Next, as shown in FIG.
The semiconductor device 3 is lowered while sucking the semiconductor device 3 with the suction tool 5, and the protruding contact 4 having the transfer portion 8 of the conductive adhesive formed at the tip is aligned with the connection electrode 7 on the circuit board 6. To bring them into contact. At this time, since the transfer portion 8 of the conductive adhesive is heated and is in a plastic state, the conductive adhesive adheres to the surface of the connection electrode 7.

Thereafter, when the heating / suction tool 5 is separated from the semiconductor device 3, the transfer portion 8 of the thermoplastic conductive adhesive is cooled and hardened, and as shown in FIG. And the connection electrode 7 of the circuit board 6 are bonded by a transfer portion 8 of a thermoplastic conductive adhesive. That is, a semiconductor device package is obtained.

In the above embodiment, since the semiconductor device and the circuit board are joined by using a thermoplastic conductive adhesive which has been plasticized in advance, the conductive adhesive is shortened when the semiconductor device is mounted on the circuit board. Can be cured in time. Therefore, the productivity of the semiconductor device package using the conductive adhesive is improved and the cost is reduced.

Further, since the semiconductor device is mounted on the circuit board using the conductive adhesive as described above, the thermal stress caused by the difference in the coefficient of thermal expansion between the semiconductor device and the circuit board can be suppressed to a very small value. A highly reliable semiconductor device package can be obtained.

In the present embodiment, when the semiconductor device 3 is mounted on the circuit board 6, the semiconductor device 3 is heated by the heating / suction tool 5, but the semiconductor device 3 is heated by the suction tool. Alternatively, only the adsorption may be performed. In this case, the circuit board 6 may be heated, and the thermoplastic conductive adhesive may be heated by another heating means such as irradiation of infrared rays.

In the above embodiment, a thermoplastic resin containing a conductive filler such as Ag in a polyester resin was used as the thermoplastic conductive adhesive. However, the conductive adhesive of the present invention is not limited to this embodiment. However, any material having thermoplasticity and conductivity may be used.

Further, in the above-mentioned embodiment, the shape of the projecting contact 4 is a simple columnar shape. However, by particularly forming the projecting contact 4 into a two-stage shape, the transfer portion 8 of the conductive adhesive can be cooled more quickly. The curing time can be shortened.

[0036]

As described above, according to the semiconductor device mounting method of the present invention, the semiconductor device and the circuit board are joined by using a thermoplastic conductive adhesive maintained in a plastic state in advance. When the semiconductor device is mounted on the circuit board, the conductive adhesive can be cured in a short time, so that the productivity of the semiconductor device package using the conductive adhesive can be improved.

Further, in the semiconductor device package obtained by the present invention, since a thermoplastic conductive adhesive is used for bonding the semiconductor device and the circuit board, a difference in thermal expansion coefficient between the semiconductor device and the circuit board is obtained. A highly reliable semiconductor device package can be obtained with little influence of the generated thermal stress.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a state of a semiconductor device and the like in a mounting process of a semiconductor device according to an embodiment.

FIG. 2 is a partial cross-sectional view of a semiconductor device package according to an embodiment.

FIG. 3 is a partial cross-sectional view showing a state when a conductive adhesive is transferred to a projecting contact of a semiconductor device in a conventional method for mounting a semiconductor device.

FIG. 4 is a partial cross-sectional view of a package obtained by a conventional method for mounting a semiconductor device.

[Explanation of symbols]

 Reference Signs List 1 coating film 2 support base 3 semiconductor device 4 projecting contact 5 heating / suction tool 6 circuit board 7 connection electrode 8 transfer section 9 semiconductor device 10 terminal electrode 11 projecting contact 12 coating 13 support base 14 circuit board 15 connection electrode 16 transfer section

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-199847 (JP, A) JP-A-5-136146 (JP, A) JP-A-6-77285 (JP, A) JP-A-5-77285 144878 (JP, A) JP-A-2-34949 (JP, A) JP-A-5-166879 (JP, A) JP-A-7-321162 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/60

Claims (6)

(57) [Claims] 1. A method for mounting a semiconductor device having a projecting contact on a circuit board face down using a conductive adhesive, wherein a coating film of a thermoplastic conductive adhesive is formed on a support base. Contacting the projecting contact of the semiconductor device with a coating of the conductive adhesive on the support base while heating the conductive adhesive on the support base to maintain the plastic state. Transferring the conductive adhesive to the semiconductor device, and contacting the projecting contact of the semiconductor device with the connection electrode of the circuit board while maintaining the transfer portion of the conductive adhesive formed in the above process in a plastic state; Cooling the conductive adhesive in a state where the protruding contact of the semiconductor device is in contact with the connection electrode of the circuit board, and bonding the two to each other. 2. The method for mounting a semiconductor device according to claim 1, wherein in the step of transferring the conductive adhesive to the projecting contact of the semiconductor device, the temperature of the semiconductor device is higher than a temperature at which the conductive adhesive is in a plastic state. A method for mounting a semiconductor device, comprising: 3. The method for mounting a semiconductor device according to claim 1, wherein, in the step of bringing the projecting contact of the semiconductor device into contact with a connection electrode of a circuit board, the semiconductor device is brought into a temperature at which the conductive adhesive is in a plastic state. A method for mounting a semiconductor device, comprising heating to the above temperature. 4. The method for mounting a semiconductor device according to claim 1, wherein, in the step of bringing the projecting contact of the semiconductor device into contact with the connection electrode of the circuit board, the circuit board is heated to a temperature higher than a temperature at which the conductive adhesive is in a plastic state. A semiconductor device mounting method, wherein the semiconductor device is heated to a predetermined temperature. 5. The method for mounting a semiconductor device according to claim 1, wherein the conductive adhesive contains at least a thermoplastic resin and a conductive filler. Method. 6. The method of mounting a semiconductor device according to claim 1, wherein the projecting contact of the semiconductor device has a two-step projecting shape.