JP3645807B2 - Electronic component equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic component device on which electronic components such as piezoelectric vibrators and IC chips are mounted.
[0002]
[Prior art]
A crystal oscillator, which is an example of a conventional electronic component device, has already been known to have a structure as disclosed in Japanese Patent Laid-Open No. 8-204452 (FIGS. 4 to 6).
The structure is a so-called CSP (Chip Size Package) structure, and the crystal oscillator 51 includes a ceramic package (surface mount type electronic component storage package) 52 having a cavity on both sides, and a crystal resonator (electronic component). 53, a conductive adhesive member 54, and an IC chip 57.
As shown in FIG. 5, the quartz vibrator 53 has excitation electrodes 53b attached to both main surfaces of a strip-like quartz substrate 53a. Further, an extraction electrode 53c extending from each excitation electrode was attached to one short side of the quartz substrate 53a.
[0003]
The ceramic package 52 is formed by stacking ceramic insulating plates 521a to 521c such as alumina, and a seal ring 523 for forming a cavity 520a is formed on one main surface side in the stacking direction, and on the other main surface side in the stacking direction. A ring-shaped ceramic insulating plate 522 for forming the cavity 520b is formed. In one cavity 520a, a crystal resonator 53 is accommodated in an electrode pad 524 formed on the bottom surface so that the extraction electrode 53c is placed, and is fixed and connected by a conductive adhesive member 54, and the cavity 520a is sealed. A metal lid 55 is seam welded to 523 and hermetically sealed.
[0004]
An IC chip 57 is mounted and connected to the bottom surface of the other cavity 520b by a flip chip method or a wire bonding method. The cavity 520 b is filled with a filling resin 58 so as to cover the IC chip 57.
[0005]
The crystal unit 53 and the IC chip 57 described above are connected by a predetermined wiring pattern 59 formed inside the ceramic package 52 to form an oscillation circuit, and are extended to an external terminal electrode 525 formed around the opening of the cavity 520b. .
[0006]
[Problems to be solved by the invention]
However, there have been the following problems.
That is, as shown in FIG. 6, in the conventional crystal oscillator 51, the external terminal electrode 525 is formed around the opening of the cavity 520b on the side where the IC chip 57 of the ceramic package 52 is accommodated. If an attempt is made to make such an area, the area for mounting an oscillation component such as the IC chip 57 cannot be made very small, so it is necessary to reduce the width of the peripheral portion of the opening of the cavity 520b. There is a problem that the area of the electrode 525 is also reduced. In this case, when the crystal oscillator 52 is mounted on a circuit board (not shown), there is a problem that sufficient connection strength cannot be obtained even if the external terminal electrode 525 is soldered on the circuit board. In addition, there is also a problem that an abnormal structure can occur in terms of electrical connection.
[0007]
In recent years, it is necessary to downsize any one of the crystal resonator 53, the IC chip 57, and the ceramic package 52 in response to a request for downsizing the crystal oscillator 51 that is an electronic component device.
On the other hand, in addition to the above-mentioned miniaturization, there is a demand for higher functionality of the crystal oscillator 51. However, in addition to the IC chip 57 in addition to the IC chip 57 accompanying the higher functionality, In some cases, the oscillation circuit becomes complicated, and the number of transmission parts mounted in the cavity 520b of the ceramic package 52 as in the prior art increases.
[0008]
Accordingly, when a small crystal unit 53 is used and the ceramic package 52 is formed in a small size in response to a demand for miniaturization and high functionality, an IC chip or the like is mounted along with the miniaturization of the ceramic package 52. As a result, the size of the cavity 520b in the region is reduced, and it has been difficult to mount high-functionality complex oscillator circuit components at a time.
[0009]
The present invention has been devised in view of the above-described problems, and its purpose is to provide a terminal even if the size of a cavity in a region where an IC chip or the like is mounted is reduced as the electronic component device is downsized. An object of the present invention is to provide an electronic component device in which a region for forming an electrode is sufficiently wide to obtain a sufficient connection strength between a circuit board and a terminal electrode.
[0010]
In addition, even if the electronic component device is downsized and the cavity size is reduced, it is possible to mount complex circuit components with advanced functions at the same time, and sufficient connection strength with the electrodes on the circuit board can be obtained. It is to supply an electronic component device.
[0011]
[Means for Solving the Problems]
An electronic component device according to the present invention includes a rectangular container formed with a cavity having a substantially rectangular opening on one main surface, a plurality of electrode pads for storing electronic components on the bottom of the cavity, and the cavity And an electronic component having an input / output electrode connected to the electrode pad, wherein the circuit component for driving the electronic component is mounted on the other main surface of the container. The cavity of the container is formed so that each corner of the cavity opening comes near the center of each side of the outer periphery of the one main surface of the container, and one side of the cavity opening and the one main surface of the container A terminal electrode for connecting surface mounting solder is formed in each region surrounded by two adjacent sides on the outer periphery.
[0012]
According to the present invention, each corner of the cavity opening is formed near the center of each side of the outer periphery of the one main surface of the container, so that one side of the cavity opening and the one main surface of the container are formed. A substantially triangular region surrounded by two adjacent sides on the outer periphery is formed, and since a terminal electrode for connecting surface mounting solder is formed in this region, even if a cavity for storing electronic components is formed, The formation area of the terminal electrode can be maximized, whereby a solder ball can be formed large and sufficient mechanical strength can be obtained when mounted on a circuit board.
[0013]
In the electronic component device of the present invention, the electronic component is a piezoelectric vibrator in which the input / output electrodes are formed on both principal surfaces of the piezoelectric substrate, and the circuit component is an oscillation circuit component that drives the piezoelectric vibrator. It is characterized by being.
[0014]
According to the above-described configuration, the main surface on the cavity side containing electronic components such as a piezoelectric vibrator is the mounting surface on the circuit board, which is opposite to the conventional case, and the other main surface of the container is mounted on the circuit board. The area for forming the terminal electrode is not necessary, so that it is possible to mount a large number of circuit components that drive the electronic component, and even if the electronic component device is miniaturized, the electronic component device can be highly functional. Can do.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an electronic component device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a central sectional view of an electronic component device according to the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a bottom view thereof. In the following description, an electronic component device as a crystal oscillator using a crystal resonator as an electronic component will be described as an example. Further, the electronic component device of the present invention includes an electronic component device using an electronic component such as a piezoelectric vibrator using a piezoelectric ceramic substrate or a single crystal piezoelectric substrate in addition to a crystal resonator.
[0016]
The crystal oscillator 1 of the present invention is composed of a ceramic package 2 and an IC chip 7.
[0017]
The ceramic package 2 includes a laminate 200 in which rectangular ceramic substrates 21 a to 21 c are laminated, a seal ring 23, a crystal resonator 3, and a metal lid 5.
An internal wiring pattern (not shown) is formed between the layers of the ceramic substrates 21a to 21c constituting the multilayer body 200. With this internal wiring pattern, an IC connection electrode (not shown), electrode pads 24 and 24, which will be described later, and The terminal electrode 90 is electrically connected.
The seal ring 23 is formed in a substantially rectangular shape on one main surface of the ceramic package 2 (“one main surface of the ceramic substrate 21a”, hereinafter the same), and the material thereof is Fe—Ni, Fe—Ni—Co, or the like. Made of metal. The seal ring 23 is connected to the sealing conductor film 210a formed on the inner side of the one main surface of the ceramic substrate 21a by brazing or the like, thereby forming the cavity 20. When the thickness of the cavity 20 is insufficient, a ring-shaped ceramic substrate (not shown) can be laminated around the ceramic substrate 21a, and the seal ring 23 can be attached to the surface of the ring-shaped ceramic substrate. . The sealing conductor film 210a is made of a metal such as molybdenum or tungsten, and is formed by baking a conductive resin paste on one main surface of the ceramic substrate 21a, and then Ni / Au plated on the surface. Has been.
Further, as shown in FIG. 3, the cavity 20 is formed so that each corner 20a of the opening of the cavity 20 is located near the center of each side of the outer periphery 210a of the main surface of the rectangular ceramic substrate 21a. In the figure, when the position formed so that one side of the outer surface 210a of the main surface of the ceramic substrate 21a and one side of the opening of the cavity 20 are parallel is set as a reference, it is inclined approximately 45 degrees with respect to the main surface of the ceramic substrate 21a. However, the present invention is not limited to this, and tilting is possible in the range of 0 to 90 degrees (excluding 0 and 90 degrees). When the area of one main surface of the ceramic package 2 shown in FIG. 5 is the same, if the cavity 20 is inclined with respect to the one main surface of the ceramic package 2 as shown in FIG. However, since the crystal unit 3 has a simple configuration, the size of the crystal unit 3 itself is normally relatively easy to configure compared to the size of the IC chip. Can do.
[0018]
Each of the four regions 9a surrounded by one side of the opening of the cavity 20 and two adjacent sides of the outer peripheral surface 210a of the main surface of the ceramic substrate 21a is formed in a substantially triangular shape, and the region is a circuit board (not shown). ) Solder area for mounting. A square terminal electrode 90 is formed at the center of the region 9a. One of the terminal electrodes 90 is a ground terminal, two are input / output terminals, and one is a control terminal for finely adjusting the frequency. It is composed of
[0019]
Further, the seal ring 23 and the terminal electrode 90 formed in the region 9a of the ceramic substrate 21a and the solder ball 9 are placed at a distance so as not to be short-circuited. The distance between the terminal electrode 90 and the solder ball 9 becomes short, and there is a risk of short circuit. Therefore, an insulating resin 23a such as epoxy is formed on the entire surface in the thickness direction of the seal ring 23 at the center of the side surface of the outer peripheral surface of the seal ring 23 shown in FIG.
Although not shown, instead of forming the resin on the outer peripheral surface of the seal ring 23 as described above, a short circuit between the terminal electrode 90 and the solder ball 9 is physically suppressed on the region 9a on the outer periphery of the seal ring 23. An insulating plate made of ceramic may be formed.
[0020]
A solder ball 9 is formed on the terminal electrode 90. The diameter of the solder ball 9 is such that the crystal oscillator 3 is mounted even when the crystal oscillator 1 is mounted on a circuit board (not shown) and the solder ball 9 is crushed. Is formed so as not to come into contact with the mounted circuit board. For example, when the height from the surface of the ceramic substrate 21a to the upper surface of the metal lid 5 is about 0.3 mm, the diameter of the solder ball is appropriately about 0.5 mm or more.
[0021]
On the other hand, a pair of electrode pads 24, 24 that are electrically connected to a crystal resonator 3 to be described later on the bottom surface of the cavity 20, that is, on the main surface of the ceramic substrate 21 a and on both ends in the short side near the cavity 20. Is formed. The electrode pads 24 and 24 are made of a metal such as molybdenum or tungsten.
[0022]
The quartz resonator 3 includes a strip-shaped quartz substrate 30 cut with a predetermined crystal axis (AT cut), a pair of excitation electrodes 31 and 31 formed on both main surfaces of the quartz substrate 30, and the excitation electrodes 31 and 31. The lead electrode 32 extends to one end of the quartz substrate 30. Such excitation electrodes 31 and extraction electrodes 32 are formed of Au, Ag, Cr, or the like by using a means such as vapor deposition or sputtering by arranging a mask having a predetermined shape on the upper and lower surfaces of the quartz substrate 30.
The electrical and mechanical connection between the ceramic package 2 and the crystal unit 30 is performed by a conductive resin paste that is cured to become the conductive adhesive member 4. Here, the connection of the crystal unit 3 is not limited to the conductive adhesive member 4, and a bonding wire may be used.
[0023]
The metal lid 5 is a metal plate made of, for example, an Fe—Ni alloy (42 alloy) or an Fe—Ni—Co alloy (Kovar), and the metal lid 5 injects nitrogen gas or the like into the cavity 20. Or hermetically sealed by seam welding together with the seal ring 23 in a vacuum.
[0024]
Further, after that, an insulating resin (not shown) may be applied to the upper surface of the metal lid 5 and cured. This insulating resin 5a is formed in order to prevent the solder ball 9 from being melted, connected to the electrode on the set substrate, and being short-circuited to the metal lid 5 when it is cured. An acid anhydride-based or amine-based epoxy resin in which the content of the spherical filler of alumina, which is thermosetting higher than the melting point of the balls 9, is 40 to 70% is used.
[0025]
The IC chip 7 is a circuit component in which a circuit for exciting the crystal unit 3 is integrated, and is flip-chip on the flat surface of the other main surface of the ceramic package 2 (“the other main surface of the ceramic substrate 21c”, hereinafter the same). IC connection electrodes (not shown) that are electrically connected by a method such as the above are formed and connected via Au bumps 7a. Further, in FIG. 1, only the IC chip 7 is placed on the other main surface of the ceramic substrate 21c. However, compared with FIGS. 4 to 6 of the conventional configuration, the main surface of the ceramic substrate 521b is the same as the other main surface. Since the ceramic substrate 21c of the present invention does not serve as a mounting surface, the conventional terminal electrodes 525 and cavities 520b are not formed, so that electronic component elements such as a chip capacitor and a chip resistor are mounted in addition to the IC chip 7, although not shown. May be placed.
The IC chip 7 is connected by bonding an Ag paste that becomes the Au bump 7a or by fusing with an ultrasonic wave. 1 and 2, a thermosetting resin 28 covering the IC chip 7 may be formed, and at least the thermosetting resin 28 is filled between the other main surface of the ceramic substrate 21c and the back surface of the IC chip. You may do it. The thermosetting resin 28 is cured by heating, so that the bonding strength between the IC chip 7 and the ceramic package 2 is reinforced. As the thermosetting resin 28, an acid anhydride-based or amine-based epoxy resin having a spherical filler content of 40 to 70% is used.
[0026]
As described above, the surface on which the IC chip 7 of the ceramic substrate 21c is mounted is not a mounting surface on the circuit board, so that no cavity or terminal electrode is provided, and the safety tolerance of the mounting region of the IC chip 7 is included. However, the entire area of the ceramic package 2 can be reduced.
The above-described crystal oscillator 1 is manufactured as follows.
[0027]
First, a strip-shaped quartz substrate 3 is prepared. Next, the excitation electrodes 31 are formed on both main surfaces of the quartz substrate 30, and the extraction electrodes 32 led out from the excitation electrode 31 are formed on both surfaces of the quartz substrate 30, thereby producing the quartz crystal resonator 3. At the same time, a pair of electrode pads 24, 24 are formed by electrolytic plating on the bottom surface of the ceramic package 2, that is, one main surface of the ceramic substrate 21a. A frame-shaped sealing conductor film 210a is formed so as to surround, and then the seal ring 23 is connected to the sealing conductor film 210a by brazing or the like to form the ceramic package 2.
[0028]
Next, for example, a conductive resin paste that hardens to become the conductive adhesive member 4 is supplied and applied to the electrode pads 24 and 24 with a dispenser or the like. At this time, the supplied conductive resin paste has a generally hemispherical shape.
[0029]
Then, it is placed on the conductive resin paste so that the extraction electrodes 32, 32 of the crystal unit 3 are in contact with each other. Next, the conductive resin paste is cured, and the ceramic package 2 and the crystal unit 3 are cured by heat to be bonded and fixed.
[0030]
Next, the frequency of the crystal unit 3 is adjusted. Specifically, an electrode pad (not shown) for measuring the oscillation frequency is formed on the back surface of the ceramic package 2, and the crystal resonator 3 is oscillated by connecting the power supply voltage, the ground and the frequency measuring probe. Thus, the oscillation frequency is adjusted by increasing / decreasing the mass of the excitation electrode on the excitation electrode of the quartz crystal resonator 3 by Ag vapor deposition or ion gun.
Next, the metal lid 15 is placed on the seal ring 23 in a predetermined atmosphere such as N2 or He, and both are sealed by seam welding.
[0031]
Next, the IC chip 7 is mounted on the other main surface of the ceramic package 2. Specifically, first, Au bumps 7a formed on the IC chip 7 and electrode pads (not shown) formed on the other main surface of the ceramic substrate 2c are positioned and placed at corresponding positions. Thereafter, the IC chips 7 are bonded to each other by bonding with Ag paste or fusion with ultrasonic waves.
[0032]
Next, an epoxy thermosetting resin 28 is filled so as to cover the IC chip 7 and is heated and cured. Finally, the crystal oscillator 1 is formed by forming the solder balls 9 on the terminal electrodes 90 formed at the corners of the ceramic substrate 21a on which the cavity 20 of the ceramic package 2 is formed.
[0033]
【The invention's effect】
According to the present invention, each corner of the cavity opening is formed near the center of each side of the outer periphery of the one main surface of the container, so that one side of the cavity opening and the outer periphery of the one main surface of the container Since a substantially triangular area surrounded by two adjacent sides is formed, and a terminal electrode for connecting surface mounting solder is formed in this area, even if a cavity for storing electronic components is formed, the terminal electrode As a result, the solder ball can be formed larger and sufficient mechanical strength can be obtained when mounted on a circuit board.
[0034]
Further, according to the present invention, the one main surface on the cavity side in which electronic parts such as piezoelectric vibrators are accommodated is used as a mounting surface on the circuit board opposite to the conventional one, so the other main surface of the container is mounted on the circuit board. The region for forming the terminal electrode is not necessary, so that many circuit components for driving the electronic components can be mounted, and even if the size is reduced, higher functionality can be achieved.
[Brief description of the drawings]
FIG. 1 is a central cross-sectional view (cross-sectional view taken along line AA in FIG. 3) of an electronic component device of the present invention using a crystal resonator.
FIG. 2 is a plan view of the electronic component device of the present invention.
FIG. 3 is a bottom view of the electronic component device of the present invention.
FIG. 4 is a central sectional view of a conventional electronic component device using a crystal resonator.
FIG. 5 is a plan view of a conventional electronic component device.
FIG. 6 is a bottom view of a conventional electronic component device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator 2 ... Ceramic package 20 ... Cavity part 21, 21a, 21b ... Ceramic substrate 23 ... Seal ring 3 ... Crystal oscillator 4 ... Conductive adhesive member 5 ..Metal lid 7 ... IC chip

Claims (2)

On the other hand, a rectangular container formed by forming a cavity having a substantially rectangular opening on the main surface, a plurality of electronic component storage electrode pads on the bottom surface of the cavity, and stored in the cavity, In an electronic component device comprising an electronic component having an input / output electrode to be connected and mounting a circuit component for driving the electronic component on the other main surface of the container ,
The cavity of the container is formed in the vicinity of the center of each side of the outer periphery of the one main surface of the container so that each corner of the cavity opening comes, and one side of the cavity opening and the one side of the container An electronic component device, wherein a terminal electrode for connecting surface mounting solder is formed in each region surrounded by two adjacent sides on the outer periphery of the surface. 2. The electronic component is a piezoelectric vibrator having the input / output electrodes formed on both principal surfaces of a piezoelectric substrate, and the circuit component is an oscillation circuit component that drives the piezoelectric vibrator. The electronic component device described in 1.

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