JP2003152126A - Package substrate and integrated circuit device employing it, and method for manufacturing integrated circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for manufacturing a surface acoustic wave device in which the shear strength of a surface acoustic wave element mounted on a package substrate in flip-chip system can be enhanced. SOLUTION: A surface acoustic wave element 11 having a specified conductive pattern and bump electrodes 13 formed on a piezoelectric substrate is prepared, and a package substrate 12 having external connection terminals 12a formed on the terminal forming plane opposite to the element mounting plane for mounting the surface acoustic wave element 11 while being connected electrically with a mounting substrate and a supporting layer 12b thicker than the height of the external connection terminal 12a formed at least in a region corresponding to the mounting position of the surface acoustic wave element 11 is prepared. The package substrate 12 is set on a stage 21 while directing the element mounting plane outward and the supporting layer 12b is touched to the stage 21. Subsequently, ultrasonic vibration is imparted while pressing the surface acoustic wave element 11 in the direction of the supporting layer 12b thus bonding the surface acoustic wave element 11 to the element mounting plane of the package substrate 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package substrate, an integrated circuit device using the same, and a method for manufacturing the integrated circuit device, and more particularly, to an integrated circuit device in which an integrated circuit element and a package substrate are ultrasonically bonded. The present invention relates to a technology effectively applied to improve the shear strength.

[0002]

2. Description of the Related Art Today, mobile communication devices represented by mobile phones, which have been remarkably popularized, are rapidly miniaturized. Along with this, miniaturization and higher performance are required for parts used in mobile communication devices.

Here, a demultiplexer is used for branching and generating signals in mobile communication equipment. The duplexer includes a band pass filter, a band stop filter, or a combination thereof, but in order to achieve further miniaturization and higher performance, two duplexers having different band center frequencies from each other are used. There is one in which a surface acoustic wave device equipped with a surface acoustic wave element is used.

In the surface acoustic wave device, the package substrate on which the surface acoustic wave element is mounted by the flip chip method is not made of resin, but is made of ceramic such as alumina or LTCC which is harder than resin. There is.

[0005]

SUMMARY OF THE INVENTION Here, small size, light weight,
In order to realize low cost, it is desirable that the package substrate is made of resin.

However, if the package substrate is made of a resin softer than that of ceramic, the package substrate is deflected during ultrasonic vibration in flip chip mounting, and the ultrasonic power is not sufficiently applied to the contact surface between the protruding electrode and the package substrate. , It becomes difficult to secure the necessary share strength.

Such a problem applies not only to the surface acoustic wave device but also to all integrated circuit devices in which integrated circuit elements are mounted on the package substrate by the flip chip method.

Therefore, the present invention provides a package substrate capable of improving the share strength of an integrated circuit element mounted on the package substrate by a flip chip method, an integrated circuit device using the same, and a method of manufacturing the integrated circuit device. The purpose is to provide.

[0009]

In order to solve the above-mentioned problems, the package substrate according to the present invention can mount an integrated circuit device having a predetermined conductive pattern and projecting electrodes on the device substrate on the device mounting surface. A package substrate,
On the terminal formation surface, which is the surface opposite to the element mounting surface, an external connection terminal that is electrically connected to the mounting board and a thickness equal to or higher than the height of the external connection terminal should be provided in the area corresponding to at least the mounting position of the integrated circuit element. And a supporting layer having the same are formed.

In order to solve the above-mentioned problems, the method of manufacturing an integrated circuit device according to the present invention prepares an integrated circuit element having a predetermined conductive pattern and projecting electrodes formed on an element substrate, and the integrated circuit element is An external connection terminal that is electrically connected to the mounting substrate on the terminal formation surface that is the surface opposite to the element mounting surface to be mounted, and at least the height of the external connection terminal in the area corresponding to the mounting position of the integrated circuit element. A package substrate having a support layer having a thickness of 1 is prepared, the package substrate is set on the stage with the element mounting surface facing outward, and the support layer is brought into contact with the stage to move the integrated circuit element in the support layer direction. It is characterized in that ultrasonic vibration is applied while being pressed to bond the integrated circuit element to the element mounting surface of the package substrate.

Further, in order to solve the above-mentioned problems, the method for manufacturing an integrated circuit device according to the present invention provides an integrated circuit device having a predetermined conductive pattern and projecting electrodes formed on an element substrate, Prepare a package board with external connection terminals that are electrically connected to the mounting board formed on the terminal formation surface that is the surface opposite to the element mounting surface and mount the external connection terminal formation area on the terminal formation surface. Prepare a stage having a supporting protrusion that can contact at least the area corresponding to the mounting position of the integrated circuit element, and set the package substrate on the supporting protrusion of the stage with the element mounting surface facing outward. Is applied in the direction of the support protrusion to apply ultrasonic vibration to bond the integrated circuit element to the element mounting surface of the package substrate.

According to this invention, since the package substrate does not bend during ultrasonic bonding, it is possible to greatly improve the shear strength of the integrated circuit element mounted on the package substrate by the flip chip method. .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members,
Moreover, the duplicate description is omitted. It should be noted that the embodiment of the present invention is a particularly useful embodiment for carrying out the present invention, and the present invention is not limited to the embodiment.

FIG. 1 is a cross-sectional view showing a surface acoustic wave device in which a surface acoustic wave element according to an embodiment of the present invention is packaged, and FIG. 2 shows a package substrate of the surface acoustic wave device of FIG. 3 is a schematic view showing a circuit of the surface acoustic wave element of FIG. 1, FIG. 4 is a plan view showing a part of the surface acoustic wave element of FIG. 3, and FIG. 5 is a surface acoustic wave device of FIG. 6 is an explanatory view showing a state at the time of mounting an ultrasonic wave in FIG. 6, FIG. 6 is a graph showing a relationship between ultrasonic power and shear strength in the surface acoustic wave device of FIG. 1 together with a comparative example, and FIG. 7 is another embodiment of the present invention. FIG. 3 is an explanatory diagram showing a state when ultrasonic waves are mounted in the surface acoustic wave device.

A surface acoustic wave device 10 shown in FIG. 1 has a surface acoustic wave element (integrated circuit element) 11 in which a predetermined conductive pattern and projecting electrodes 13 are formed on a piezoelectric substrate (element substrate).
Is a resin-made package substrate 12 formed of a single layer or a plurality of layers and having predetermined wiring patterns and circuit patterns formed thereon.
It was installed in.

The surface of the surface acoustic wave device 11 on which the conductive pattern is formed is disposed so as to face the package substrate 12. As shown in the figure, the surface acoustic wave device 11 is provided with a protruding electrode on the device mounting surface of the package substrate 12. Flip-chip connection is made via 13.

The package substrate 12 has an external connection terminal 12a electrically connected to a mother board (mounting substrate) (not shown) on a terminal forming surface opposite to the element mounting surface.
Are formed. Further, as shown in FIG. 2, the external connection terminals 12a are provided except in the region where the external connection terminals 12a are formed.
The support layer 12b having a thickness T that is larger than the height H is formed.

The support layer 12b is the surface acoustic wave device 11
It suffices that it is formed in a region corresponding to the mounting position of, and it may not be formed over the entire surface except the region where the external connection terminal 12a is formed as in the present embodiment. However, it goes without saying that the support layer 12b is formed avoiding the external connection terminals 12a, and the support layer 12b is not formed so as to cover the external connection terminals 12a.

Here, from the viewpoint of preventing conduction between the external connection terminals 12a formed on the terminal formation surface of the package substrate 12 and the conductive patterns by the support layer 12b, the support layer 12b is an insulating member. , A solder resist or the like, for example. However, the support layer 1
When 2b is formed in non-contact with the external connection terminal 12a and the conductive pattern, the support layer 12b does not need to have insulating properties.

The thickness T of the support layer 12b may be equal to or higher than the height H of the external connection terminal 12a. Therefore, the thickness T of the support layer 12b may be equal to or higher than the height H of the external connection terminal 12a.

Here, the piezoelectric substrate is LiNbO3, Li
It is formed of a piezoelectric single crystal such as TaO3 or quartz, or a piezoelectric ceramic such as lead zirconate titanate piezoelectric ceramics. However, ZnO on the insulating substrate
A piezoelectric substrate on which a piezoelectric thin film such as a thin film is formed may be used.

A cap (sealing member) 14 for hermetically sealing the surface acoustic wave element 11 is provided on the package substrate 12.
Are bonded to protect the surface acoustic wave element 11 from dust and mechanical shock. The surface acoustic wave element 11
May be resin-sealed.

On the piezoelectric substrate of the surface acoustic wave element 11 mounted on the surface acoustic wave device 10 as described above, as shown in FIG. 3, the excitation electrode portion 1 resonating with the surface acoustic wave of a predetermined frequency is formed.
5 is formed. The excitation electrode portion 15 is electrically connected to the excitation electrode portion 15 and the package substrate 12, and an input electrode 16, an output electrode 17, and a ground electrode 18 for inputting and outputting an electric signal to and from the excitation electrode portion 15 are provided in the wiring portion. It is electrically connected via 19. The wiring portion 19 electrically connects the excitation electrode portion 15 and the electrodes 16, 17, 18 and the excitation electrode portion 15 to each other. The excitation electrode portion 15 and the wiring portion 19 are formed of aluminum or aluminum alloy. However, members other than aluminum or aluminum alloy may be included.

The electrodes 16, 17 and 18 and the package substrate 12 are bump-connected by ultrasonic waves by forming the protruding electrodes 13 shown in FIG. 1 on them.

Here, the excitation electrode portion 15 is formed in the shape of a pair of interdigitated comb teeth, as shown in FIG. When a voltage is applied to the excitation electrode section 15 on the input side to apply an electric field, a surface acoustic wave is generated on the piezoelectric substrate due to the piezoelectric effect. Further, the mechanical distortion due to the surface acoustic waves generated in this way causes an electric field, and is converted into an electric signal at the excitation electrode section 15 on the output side. Reflectors 20 for reflecting surface acoustic waves are arranged on both sides of the excitation electrode portion 15.

In this embodiment, the wiring portion 19 between the input electrode 16 and the output electrode 17 is used as a serial arm, and the parallel arm having a plurality of wiring portions 19 is provided between the series arm and the ground electrode 18. , And a ladder type circuit in which the excitation electrode portions 15 are arranged on the series arm and the parallel arm is configured, but the ladder type circuit may be other than the ladder type circuit.

Next, a method of manufacturing the surface acoustic wave device having such a structure will be described with reference to FIG.

First, the surface acoustic wave device 11 and the package substrate 12 described above are prepared.

Next, the package substrate 12 is set on the stage 21 with the element mounting surface facing outward, and the support layer 12b is formed.
And the stage 21 are brought into contact with each other.

Then, ultrasonic vibration is applied while pressing the surface acoustic wave element 11 held by the holding member 22 toward the support layer 12b, and the surface acoustic wave element 11 is bonded to the element mounting surface of the package substrate 12. .

After the surface acoustic wave element 11 is bonded to the element mounting surface of the package substrate 12, the surface acoustic wave element 1 is
The cap 14 is adhered to the package substrate 12 so as to surround the package substrate 1.

Here, the package substrate 12 and the stage 2
Since the support layer 12b located between the substrate 2 and the substrate 2 prevents the package substrate 12 made of resin from being bent during ultrasonic bonding, sufficient ultrasonic power is applied to the contact surface between the protruding electrode 13 and the package substrate 12. Like

FIG. 6 shows the relationship between ultrasonic power and shear strength.

As shown in FIG. 6, by forming the support layer 12b on the package substrate 12, the share of the surface acoustic wave element 11 mounted on the package substrate 12 by the flip chip method is increased as compared with the case where the support layer is not provided. Strength is greatly improved. In addition, in FIG. 6, 6 W is obtained when there is no support layer.
The sharp decrease in shear strength is due to the vibration of the package substrate 12 at 6 W or more because the piezoelectric substrate (here, LiTaO3) is cracked.

Since the shear strength is greatly improved in this way, the bonding failure of the surface acoustic wave element 11 can be reduced.

Further, as a result, sufficient bonding strength can be obtained with a lower ultrasonic power, so that the surface acoustic wave element 11 can be bonded to the package substrate 12 efficiently.

Here, the support layer 12 is for preventing the resin package substrate 12 from flexing and lowering the shear strength during ultrasonic mounting.

In the above description, the package substrate 1
The support layer 12b is formed on the substrate 2 to prevent the package substrate 12 from bending during ultrasonic mounting. However, as shown in FIG. 7, the package substrate 12 is prevented from bending without forming the support layer 12b. can do.

That is, the surface acoustic wave device 11 is prepared as described above, and the package substrate 12 is prepared without the support layer 12b. In addition, the stage 21 includes the external connection terminals 12 on the terminal formation surface of the package substrate 12.
A support protrusion 21a capable of contacting a region other than the region where a is formed
Prepare the one that has. It is sufficient that at least the area corresponding to the mounting position of the surface acoustic wave element 11 can contact the support protrusion 21a, and all the areas except the area where the external connection terminal 12a is formed cannot contact. Good.

Next, the package substrate 12 is set on the support protrusion 21a of the stage 21 with the element mounting surface facing outward.

Then, ultrasonic vibration is applied while pressing the surface acoustic wave element 11 held by the holding member 22 in the direction of the support protrusion 21a, and the surface acoustic wave element 11 is bonded to the element mounting surface of the package substrate 12.

According to this, the support projection 2 of the stage 22
Deflection of the resin-made package substrate 12 at the time of ultrasonic bonding is prevented by 1a, so that sufficient ultrasonic power is applied to the contact surface between the protruding electrode 13 and the package substrate 12. Therefore, the shear strength of the surface acoustic wave element 11 mounted on the package substrate 12 by the flip chip method can be significantly improved, and the bonding failure of the surface acoustic wave element 11 can be reduced.

Further, since the sufficient bonding strength can be obtained with a lower ultrasonic power, the surface acoustic wave element 11
Can be efficiently bonded to the package substrate 12.

In the above description, the surface acoustic wave device 10 in which one surface acoustic wave element 11 is mounted is shown. However, for example, two surface acoustic wave elements having different band center frequencies are mounted and separated. The surface acoustic wave element of the present invention, such as a wave device, can be applied to various types of surface acoustic wave devices.

Further, in the present embodiment, the package substrate 12 is made of resin, which easily bends when ultrasonic waves are applied, and the function and effect of the present invention remarkably appear. However, it may be made of ceramic.

Further, the present invention is not limited to such a surface acoustic wave device, and an integrated circuit element having a predetermined circuit pattern formed on an element substrate such as a piezoelectric substrate or a silicon substrate is provided on a package substrate. The present invention can be applied to various integrated circuit devices mounted in.

[0047]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1) As the flexure of the package substrate during ultrasonic bonding is prevented, sufficient ultrasonic power is applied to the contact surface between the protruding electrode and the package substrate, and it is mounted on the package substrate by the flip chip method. It is possible to significantly improve the shear strength of the integrated circuit device. (2) Since the shear strength of the integrated circuit device mounted on the package substrate by the flip-chip method can be significantly improved as described above, the bonding failure of the integrated circuit device can be reduced. (3). Since sufficient bonding strength can be obtained with lower ultrasonic power, it becomes possible to efficiently bond the integrated circuit element to the package substrate.

[Brief description of drawings]

FIG. 1 is a sectional view showing a surface acoustic wave device in which a surface acoustic wave element according to an embodiment of the present invention is packaged.

FIG. 2 is a plan view showing a package substrate of the surface acoustic wave device of FIG. 1 from a terminal formation surface.

FIG. 3 is a schematic diagram showing a circuit of the surface acoustic wave device of FIG.

FIG. 4 is a plan view showing a part of the surface acoustic wave element of FIG.

5 is an explanatory diagram showing a state of the surface acoustic wave device of FIG. 1 when ultrasonic waves are mounted.

6 is a graph showing the relationship between ultrasonic power and shear strength in the surface acoustic wave device of FIG. 1 together with a comparative example.

FIG. 7 is an explanatory diagram showing a state of the surface acoustic wave device according to another embodiment of the present invention at the time of ultrasonic mounting.

[Explanation of symbols]

10 Surface acoustic wave device (integrated circuit device) 11 Surface acoustic wave device (integrated circuit device) 12 Package substrate 12a External connection terminal 12b support layer 13 Projection electrode 14 cap 15 Excitation electrode part 16 input electrodes 17 Output electrode 18 Ground electrode 19 Wiring part 20 reflector 21 stages 21a Support protrusion

Claims (8)

[Claims] 1. A package substrate on which an integrated circuit device having a predetermined conductive pattern and projecting electrodes formed on the device substrate can be mounted on a device mounting surface, and the package substrate is provided on a terminal formation surface opposite to the device mounting surface. Is formed with an external connection terminal electrically connected to the mounting substrate, and a support layer having a thickness equal to or greater than the height of the external connection terminal in at least a region corresponding to a mounting position of the integrated circuit element. A package substrate. 2. The package substrate according to claim 1, an integrated circuit element having a predetermined conductive pattern and a protruding electrode formed on the element substrate and mounted on an element mounting surface of the package substrate, and the integrated circuit element. An integrated circuit device having a sealing member for sealing. 3. An integrated circuit element having a predetermined conductive pattern and projecting electrodes formed on an element substrate is prepared, and mounted on a terminal forming surface opposite to an element mounting surface on which the integrated circuit element is mounted. An external connection terminal that is electrically connected to the substrate, and a package substrate in which a support layer having a thickness equal to or higher than the height of the external connection terminal is formed in a region corresponding to at least the mounting position of the integrated circuit element, The package substrate is set on the stage with the element mounting surface facing outward, the supporting layer and the stage are brought into contact with each other, and ultrasonic vibration is applied while pressing the integrated circuit element toward the supporting layer. A method of manufacturing an integrated circuit device, comprising bonding an integrated circuit device to a device mounting surface of the package substrate. 4. The method of manufacturing an integrated circuit device according to claim 3, wherein the support layer has an insulating property. 5. An integrated circuit element having a predetermined conductive pattern and projecting electrodes formed on an element substrate is prepared, and a mounting substrate is provided on a terminal forming surface opposite to an element mounting surface on which the integrated circuit element is mounted. A package substrate having external connection terminals electrically connected to is prepared, and at least a region corresponding to a mounting position of the integrated circuit element except for a region where the external connection terminals are formed is abutted on the terminal formation surface. A stage having a possible supporting protrusion is prepared, the package substrate is set on the supporting protrusion of the stage with the element mounting surface facing outward, and ultrasonic waves are applied while pressing the integrated circuit element in the supporting protrusion direction. A method of manufacturing an integrated circuit device, which comprises applying vibration to bond the integrated circuit element to an element mounting surface of the package substrate. 6. The method of manufacturing an integrated circuit device according to claim 3, wherein the package substrate is made of resin. 7. The integrated circuit device is a surface acoustic wave device having a predetermined band center frequency, and the integrated circuit device is a surface acoustic wave device on which the surface acoustic wave device is mounted. Item 7. A method for manufacturing an integrated circuit device according to any one of Items 3 to 6. 8. The method of manufacturing an integrated circuit device according to claim 7, wherein the surface acoustic wave device having two band center frequencies different from each other is mounted on the package substrate.