JP2003264442A - Manufacturing method of surface acoustic wave device and multi-chamfer base board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a surface acoustic wave device with high reliability of a resin sealed package. <P>SOLUTION: A plurality of chips on which surface acoustic wave elements are formed are prepared, a plurality of the chips are electrically and mechanically connected on a main surface of a planar base board part, a ring-shaped frame that surrounds around a plurality of the chips is arranged on the main surface of the base board part, a plurality of the chips are sealed by seal resin having fluidity and the seal resin and the base board part are made into individual fragments by every chip. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a surface acoustic wave device and a multi-chamber base substrate, and more particularly to a surface acoustic wave device using a multi-chamber base substrate for simultaneously sealing a plurality of chips with resin. It relates to a manufacturing method.

[0002]

2. Description of the Related Art In recent years, surface acoustic wave devices have been widely used as elements such as filters, delay lines, and oscillators in electronic devices that use radio waves. In the field of mobile communication and the like, miniaturization and high reliability of electronic devices used are required, and similar demands are made for surface acoustic wave devices.

In order to meet the demand for miniaturization, a conventional surface acoustic wave device adopts a flip chip bonding structure and a resin sealing structure. Further, from the viewpoint of production efficiency and the like, a manufacturing method in which a plurality of chips are bonded on one base substrate and simultaneously resin-sealed is adopted.

As shown in FIG. 5 (a), a plurality of chips 26 having surface acoustic wave elements formed thereon are electrically and mechanically connected to a multi-chamfered base substrate 27 via bumps. Then, the sheet-like sealing resin 29 having fluidity is pressed against the plurality of chips 26, whereby the plurality of chips 2
6 is simultaneously sealed with the sealing resin 29. Sealing resin 29 cured by heat and multi-sided base substrate 27
A surface acoustic wave device is manufactured by dividing into pieces.

[0005]

The surface acoustic wave device manufactured by the above method is inexpensive and rich in mass production, but it has a problem that the reliability of the resin-sealed package is low and the incidence of sealing failure is high. is doing.

Since the encapsulating resin 29 has fluidity, a part of the encapsulating resin 29 will flow down from the outer periphery of the multi-chambered base substrate 27 before being thermally cured. That is, as shown in FIG. 5B, a sufficient amount of resin 29 remains on the upper portion of the chip 26 a located at the center of the multi-chambered base substrate 27. However, the resin 29, which should remain, flows down from the multi-chambered base substrate 27 onto the upper portion of the chip 26b located at the outermost periphery. Therefore, the multi-chamfer base substrate 27
The thickness of the sealing resin 29 formed on the outer peripheral portion of the is smaller than that of the central portion. Furthermore, the upper part of the chip 26b located at the outermost periphery may be partially exposed.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is a method of manufacturing a surface acoustic wave device having a highly reliable resin-sealed package and a multi-chamber base. It is to provide a substrate.

[0008]

In order to achieve the above object, the first feature of the present invention is to prepare a plurality of chips having surface acoustic wave elements formed thereon, and to dispose the plurality of chips on a flat base substrate portion. Electrically and mechanically connected to the main surface of the base substrate, a ring-shaped frame surrounding the periphery of the multiple chips is placed on the main surface of the base substrate, and the multiple chips are sealed with a fluid sealing resin. That is, the method is a method for manufacturing a surface acoustic wave device, in which the sealing resin and the base substrate portion are separated into individual chips.

A second feature of the present invention is to prepare a plurality of chips each having a surface acoustic wave element formed thereon, and to form a flat base substrate portion and a ring-shaped frame arranged on the main surface of the base substrate portion. Prepare a multi-cavity base substrate having, and electrically and mechanically connect multiple chips to the main surface of the base substrate inside the frame, and seal multiple chips with a fluid sealing resin. The method for manufacturing a surface acoustic wave device is to separate the sealing resin and the base substrate into individual chips.

According to the feature of the present invention, the frame can prevent the sealing resin from flowing down from the base substrate portion. Therefore, the thickness of the sealing resin formed on the uppermost chip located at the outermost periphery can be maintained equal to that of the central chip.

In the feature of the present invention, it is desirable that the inner circumference of the frame is arranged between the end of the outermost chip and the outside by one chip. This is because if the distance from the inner edge of the frame to the edge of the outermost chip is too large, the flow of the sealing resin to the outside of the edge of the outermost chip at the time of sealing becomes large, and the resin is located at the outermost edge. This is because it is difficult to make the thickness of the sealing resin formed on the upper part of the chip equal to that of the chip located in the central part. However, if the size of the encapsulation resin before encapsulation is sufficiently larger (wider) than the size of the entire chip located at the outermost periphery, the effect of the frame alone is sufficient. Since a large amount of sealing resin that does not contribute to the use will be used, it is not industrially preferable. For the above reason, it is desirable that the distance between the inner edge of the frame and the edge of the outermost chip is one chip outside.

Further, it is desirable that the height of the frame is 50 μm or more higher than the height of the chip connected to the base substrate portion. This is because it is possible to sufficiently prevent the sealing resin from leaking out of the frame during sealing.

Furthermore, it is desirable that the sealing resin and the base substrate portion be separated into individual chips by punching the sealing resin and the base substrate portion using a razor blade. This is because the sealing resin and the base substrate can be accurately cut, and the chips can be cut into individual pieces without applying extra stress to the chips.

Further, it is desirable to seal a plurality of chips in a reduced pressure atmosphere. This prevents the occurrence of voids, and because the space formed between the chip and the base substrate after sealing can be sealed in a reduced pressure atmosphere, sufficient sealing can be obtained, and the deterioration of the chip characteristics can be prevented. This is because it becomes possible.

Further, it is desirable that the sealing resin has a transparent layer on at least a part thereof. This is because if the encapsulating resin has a transparent layer, the inside of the encapsulated chip can be easily inspected when inspecting chipping or the like and performing defect analysis.

A third feature of the present invention is that a plurality of chips, each having a surface acoustic wave element formed thereon, are electrically and mechanically connected to each other, and a flat base substrate portion is disposed on the main surface of the base substrate portion. And a ring-shaped frame that surrounds the periphery of a plurality of chips.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and width of layers, the ratio of the thickness of each layer, and the like are different from actual ones. Further, it is needless to say that the drawings include parts in which dimensional relationships and ratios are different from each other.

As shown in FIG. 1A, the surface acoustic wave device according to the embodiment of the present invention has a flat base substrate portion 4.
A chip 6 having at least the comb-teeth electrode 5 arranged above the flat base substrate portion 4, a sealing resin 3 for sealing the chip 6, and an electrical connection between the base substrate portion 4 and the chip 6. And a plurality of protruding electrodes 2 that are mechanically and mechanically connected to each other. The chip 6 is arranged almost at the center of the base substrate 4.

As shown in FIG. 1B, which is a sectional view taken along the line AA 'in FIG. 1A, the protruding electrode 2 is disposed between the base substrate portion 4 and the chip 6, and both Are connected. The sealing resin 3 is arranged not only on the upper surface of the chip 6 but also on the side surface thereof.

The sealing resin 3 has a function of protecting the chip 6 from environmental stress and mechanical stress. For example,
As the sealing resin 3, a polyimide resin, a PP / EPR-based polymer alloy (PP / Ethylene Propylene Rubber Blen
d), TEX (Polyolefin TPE (Polyolefine Thermoplastic Elastomer) manufactured by Tonen Chemical Co., Ltd.),
Toughprene (made by Asahi Kasei Corporation, SBS
diene-Styrene Block Copolymer)), Maxloy A
(Nippon Synthetic Rubber Co., Ltd.), X-9 (Unitika Corp., PA / PAR (PA / Polyarylate)), Tenac (Asahi Kasei Corp., POM / TPU (POM / Thermoplas)
Polymeric materials such as tic Polyurethane)) can be used. In the embodiment, a colorless and transparent resin is used as the sealing resin 3.

As the base substrate portion 4, a ceramic substrate or a flexible substrate made of one or more polymer materials selected from bismaleimide / triazine, polyimide (BT resin), polyimide and polyphenylene ether can be used. it can. Further, although Au bumps containing gold (Au) as a main component are used as the bump electrodes 2, tin-lead (SnP) is used instead of Au bumps.
It is also possible to use solder balls of type b). The thickness of the base substrate portion 4 is not specified as long as it has a required strength, but is 100 to 200 μm.
Is desirable. In the embodiment, a flexible substrate made of BT resin having a thickness of 180 μm is used as the base substrate portion 4.

On the chip 6, a surface acoustic wave element having the piezoelectric substrate 1 and a metal film pattern including the comb-teeth electrode 5 formed on the main surface of the piezoelectric substrate 1 is formed. The metal film pattern is formed on the main surface of the piezoelectric substrate 1 facing the base substrate portion 4. That is, the surface acoustic wave device has a flip chip bonding structure. Although not shown, the comb-teeth electrode 5 is a metal electrode having two or more comb-teeth-like planar shapes that mesh with each other. The surface acoustic wave (SAW) is excited and detected by the comb electrode 5. An electric signal is applied to the input interdigital transducer of the comb-teeth electrode 5, which is converted into a surface acoustic wave and transmitted on the piezoelectric substrate 1. Further, the surface acoustic wave reaching the output interdigital transducer of the other comb-teeth electrode 5 is converted into an electric signal again and can be taken out to the outside. The metal used as the material of the comb-teeth electrode 5 is, for example, Al (aluminum) or an alloy containing Al as a main component. In the latter case, copper (Cu), silicon (Si) or the like can be used as an additive. The metal film pattern includes, in addition to the comb-teeth electrode 5, an electrode pad connected to the protruding electrode 2 and a reflector for reflecting surface acoustic waves.

The electric signal applied to the input interdigital transducer and the electric signal converted into the electric signal again by the output interdigital transducer are input from the base substrate portion 4 via the protruding electrodes 2 or the base substrate portion. 4 is output. Although not shown, wirings connected to each other are formed on the front and back surfaces of the base substrate portion 4, and electric signals are transmitted and received through these wirings. Further, the sealing resin 3 is not arranged around the comb-teeth electrode 5. A hollow region is formed in the active area of the chip 6 on which the comb-teeth electrode 5 is formed. This is to enable the comb-teeth electrode 5 to excite and detect the surface acoustic wave and to propagate the surface acoustic wave normally on the piezoelectric substrate 1.

As the piezoelectric substrate 1, lithium tantalate (LiTaO ₃ ) and lithium niobate (LiNb) are used.
A single crystal substrate made of O ₃ ), a lithium barium oxide substrate (LiB ₄ O ₇ ), sapphire, quartz (SiO ₂ ), or the like can be used. Alternatively, instead of these single crystal substrates, lead titanate (PbTiO ₃ ), lead zirconate titanate (PbZrTiO ₃ (PZT)),
Alternatively, it is also possible to use a piezoelectric ceramic substrate made of these solid solutions.

The surface acoustic wave device shown in FIGS. 1A and 1B can be manufactured by the procedure shown below as an example.

(A) First, as shown in FIG. 2A, a metal film having a film thickness of about several hundreds nm is formed on the wafer-shaped piezoelectric substrate 1. A resist film is formed on this metal film, and the resist film is exposed and developed by photolithography. Then, the metal film is selectively etched by the reactive ion etching (RIE) method using the resist film as a mask,
A metal film pattern including the comb electrode 5 is formed. The metal film can be formed by a metal vapor deposition method, a sputtering method, or a chemical vapor deposition (CVD) method.

(B) Next, as shown in FIG. 2B, the bump electrode 2 is formed on the electrode pad of the metal film pattern by using the bump bonding apparatus.

(C) Next, as shown in FIG. 2 (c), the wafer-shaped piezoelectric substrate 1 is cut into individual surface acoustic wave elements by using a dicing device, that is, divided into individual pieces, and a plurality of chips 6 are formed.
To manufacture.

(D) Next, as shown in FIG. 3 (b) of the cross section taken along the line BB ′ of FIG. 3 (a) and FIG. 3 (a), a multi-cavity base substrate (7, 8) is prepared. The multi-cavity base substrate (7, 8) includes a flat base substrate portion 7 to which a plurality of chips 6 are electrically and mechanically connected,
It has a ring-shaped frame 8 arranged on the main surface of the base substrate part 7 and surrounding the periphery of the plurality of chips 6. Here, the "base substrate portion 7" indicates a substrate for taking a large number of surface acoustic wave devices, and the plurality of "base substrate portions 4" shown in FIGS. 1 (a) and 1 (b) are continuously and integrally formed. It has been done. Therefore, the thickness and the material are the same as those of the base substrate part 4.

The inner circumference of the frame 8 is arranged at a position 1 mm outward from the end of the outermost chip 6 (mounting area for the plurality of chips 6). The inner circumference of the frame 8 is the outermost chip 6
It is desirable to be arranged between the end of the chip and the outside by one chip. The frame 8 has a height of 500 μm and a width of 1
It is 0 mm. The multi-cavity base substrate (7, 8) is created by stacking and adhering the base substrate portion 7 and the frame 8.

(E) Next, a plurality of chips 1 are connected to the multi-chambered base substrate (7, 8) via the protruding electrodes 2 by using a flip chip bonding device. Here, about 400 chips 6 are connected on one multi-sided base substrate (7, 8). Specifically, the chip 6 is pressed against the main surface of the base substrate portion 7 with a predetermined pressure and, at the same time, ultrasonic waves are applied to the protruding electrode 2 and the base substrate portion 7 to bond them. The chip 6 and the base substrate portion 7 are electrically and mechanically connected to each other via the protruding electrode 2.
It is desirable that the height (500 μm) of the frame 8 be appropriately set according to the height of the connected chip 6. Specifically, it is desirable to set the height of the frame 8 to be 50 μm or more higher than the height of the chip 6 connected to the base substrate portion 7. As described above, the outermost tip 6 is
The frame 8 is arranged at a position 1 mm away from the inner circumference of the frame 8.

(F) Next, as shown in FIG. 4 (a), a plurality of chips 6 are simultaneously sealed with a fluid sealing resin 3 in a reduced pressure atmosphere. Specifically, the sheet-shaped sealing resin 3 is placed on the chip 6. Then, a force is applied so as to sandwich the sealing resin 3 and the base substrate portion 7, and at the same time, heat is applied to the sealing resin 3. The sealing resin 3 enters the gap between the adjacent chips 6, so that not only the chip 6 but also the side surface thereof can be covered with the sealing resin 3. Since the sealing resin 3 contains a thermosetting component, it is cured by the applied heat. In this way, the plurality of chips 6 can be simultaneously sealed with the sealing resin 3.

The sheet-shaped sealing resin 3 is used for the chip 6
It is preferable that the size is such that it covers the upper part of the frame instead of the size of the mounting area because it is possible to further prevent the occurrence of voids on the side surface of the chip 6 after sealing.

Here, the sealing resin 3 has adhesiveness. By pressing the sealing resin 3 up to the height of the frame (500 μm) using a predetermined mold, the height of the sealing resin 3 can be made uniform to 500 μm for all the chips 6. Therefore, the total thickness of the base substrate portion 7 and the sealing resin 3 is 680 μm.

In the above example, the sheet-like resin is used as the sealing resin 3 before the sealing process, but the present invention is not limited to this, and after the fluid resin is placed in the entire frame 8, a squeegee or the like is used. It is also possible to set the upper surface to a side having a height corresponding to the height of the frame, and then to cure it so that the plurality of chips 6 are simultaneously sealed with the sealing resin 3.

(G) Finally, as shown in FIG.
The base substrate portion 7 and the sealing resin 3 are separated into individual chips 6. Here, a razor-shaped blade is pressed against the sealing resin 3 or the base substrate portion 7 and punched by a press to obtain individual pieces. Of course, dicing may be performed using rotating teeth (dicing blade). Through the above procedure, the surface acoustic wave device shown in FIGS. 1A and 1B can be manufactured.

As described above, according to the embodiment of the present invention, the frame 8 can prevent the sealing resin 3 from flowing down from the base substrate portion 7. Therefore, the thickness of the sealing resin 3 formed on the uppermost chip 6 located at the outermost periphery can be maintained equal to that of the chip 6 located at the center.

Further, the frame 8 can prevent the sealing resin 3 from flowing out and at the same time suppress the force applied to the sealing resin 3 from escaping to the outside, and can remarkably improve the resin sealing property. Further, by performing resin sealing in a reduced pressure atmosphere, it is possible to suppress the generation of voids inside the sealing resin 3.

Furthermore, by pressing the sealing resin 3 to the height of the frame 8, the thickness of the sealing resin 3 can be uniformly controlled for the plurality of chips 6 by the height of the frame 8.

Furthermore, by providing the frame 8 on the outer periphery of the base substrate portion 7, the mechanical strength of the base substrate portion 7 is increased. Therefore, the thickness of the base substrate part 7 can be reduced. For example, by providing the frame 8 in the peripheral portion of the ceramics substrate 7, it is possible to reinforce the strength deterioration of the ceramics substrate 7 due to thinning, and it is possible to contribute to the height reduction of the surface acoustic wave device. In addition, a thinner base substrate 7 can be used.

Furthermore, by using the colorless and transparent sealing resin 3, it becomes easy to observe the inside when inspecting the chipping or the like and conducting the failure analysis.

Although the present invention has been described by way of one embodiment as described above, it should not be understood that the description and drawings forming a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments for those skilled in the art,
Examples and operational techniques will be clear.

In the embodiment of the present invention, first, a multi-faced base substrate including the base substrate portion 7 and the frame 8 is prepared,
Then, the chip 6 was connected to the inside of the frame 8. However, the present invention is not limited to this. The chip 6 may be first connected to the base substrate portion 7 to which the frame 8 is not connected, and then the frame 8 may be connected to the outside of the chip 6. That is, the chip 6 and the frame 8 may be connected to the base substrate portion 7 in any order.

Although the case where the entire sealing resin 3 is colorless and transparent has been described, a part of the sealing resin 3 may be a transparent layer.

The multi-chamfered base substrate (7, 8) is
The base substrate portion 7 and the frame 8 are not limited to those divided, and a multi-chambered base substrate integrally formed with them may be used.

Although the surface acoustic wave device has been described as an example of the electronic component device, the present invention can be similarly applied to an electronic component device using resin sealing.

As described above, it should be understood that the present invention includes various embodiments and the like not described here. Therefore, the present invention is limited only by the matters specifying the invention according to the scope of claims appropriate from this disclosure.

[0048]

As described above, according to the present invention,
It is possible to provide a method for manufacturing a surface acoustic wave device having a highly reliable resin-sealed package and a multi-chamber base substrate.

[Brief description of drawings]

FIG. 1A is a transparent perspective view showing a surface acoustic wave device according to an embodiment of the present invention. FIG. 1B is a cross-sectional view of the surface acoustic wave device taken along the section plane AA ′ of FIG.

2A to 2C are process cross-sectional views showing a method of manufacturing a surface acoustic wave device according to an embodiment of the present invention (No. 1).

FIG. 3A is a cross-sectional view showing a manufacturing step in a method of manufacturing a surface acoustic wave device according to an embodiment of the present invention. FIG. 3B is a cross-sectional view taken along the line BB ′ of FIG.

FIG. 4A and FIG. 4B are process cross-sectional views showing a method of manufacturing a surface acoustic wave device according to an embodiment of the present invention (No. 2).

FIG. 5A is a cross-sectional view showing a manufacturing step in a method of manufacturing a surface acoustic wave device according to a conventional technique. FIG. 5B is a cross-sectional view taken along the line CC ′ of FIG.

[Explanation of symbols]

1 Piezoelectric substrate 2 protruding electrodes 3 Sealing resin 4, 7 Base board part 5 Comb-shaped electrode 6 chips 8 frames

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5F061 AA01 BA03 CA03 CA22                 5J097 AA24 AA32 FF03 GG03 GG04                       HA07 HA08 JJ03 JJ09 KK10                       LL08

Claims (8)

[Claims] 1. A plurality of chips on which a surface acoustic wave element is formed are prepared, and the plurality of chips are electrically and mechanically connected to a main surface of a flat base substrate part, the base substrate part A ring-shaped frame surrounding the periphery of the plurality of chips is arranged on the main surface of, and the plurality of chips are sealed with a sealing resin having fluidity, and the sealing resin and the base substrate part are A method of manufacturing a surface acoustic wave device, characterized in that each chip is divided into individual pieces. 2. A multiple chamfered base substrate having a plurality of chips on which surface acoustic wave elements are formed and having a flat base substrate portion and a ring-shaped frame arranged on the main surface of the base substrate portion. And electrically and mechanically connecting the plurality of chips to the main surface of the base substrate portion inside the frame, and sealing the plurality of chips with a sealing resin having fluidity. A method for manufacturing a surface acoustic wave device, characterized in that the encapsulating resin and the base substrate portion are divided into individual chips. 3. The inner circumference of the frame is arranged between the end of the outermost chip and the outside of one chip by one chip. Manufacturing method of the surface acoustic wave device. 4. The surface acoustic wave device according to claim 1, wherein the height of the frame is 50 μm or more higher than the height of the chip connected to the base substrate portion. Manufacturing method. 5. The singulation of the sealing resin and the base substrate portion for each chip is punching the sealing resin and the base substrate portion with a razor blade. Either claim 1 or claim 1
A method for manufacturing a surface acoustic wave device according to the item. 6. The method of manufacturing a surface acoustic wave device according to claim 1, wherein the plurality of chips are sealed in a reduced pressure atmosphere. 7. The method of manufacturing a surface acoustic wave device according to claim 1, wherein the sealing resin has a transparent layer at least in a part thereof. 8. A flat base substrate portion to which a plurality of chips having surface acoustic wave elements are electrically and mechanically connected, and a plurality of the plurality of base substrate portions arranged on the main surface of the base substrate portion. A multi-sided base substrate having a ring-shaped frame surrounding the periphery of the chip.