JP2003142524A - Electronic component and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component wherein the infiltration of sealing resin into an inner cavity is prevented. SOLUTION: A device chip 1 having a specified functional part 8 and a substrate 3 made of a specified material (resin, ceramic, or the like) are electrically and mechanically connected with each other by conductive bumps 2, so that a specified cavity 7 containing the part 8 is formed between the chip 1 and the substrate 3. The component is so constituted that the part 8 of the chip 1 is protected from the outside (outside air) by a protective material 5 made of resin or the like. An area 9, wherein the gap between the substrate 3 and the chip 1 is wider than the area containing the part 8, is provided between the edge of the chip 1 and the part 8, and the material 5 terminates in this area 9. In this design, the resin 5 in its liquid state is prevented from entering by capillarity into the cavity 7 containing the part 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an electronic component device using, for example, a bump connection method and a resin sealing method.

[0002]

2. Description of the Related Art A typical example of an electronic component device using a bump connection method and a resin encapsulation method is a surface acoustic wave filter device (SAW).
Also called a filter). The surface acoustic wave filter device is configured by forming a functional portion (interdigital converter / IDT) having comb-shaped electrodes on a piezoelectric substrate (device chip). Since this surface acoustic wave filter device is a passive element, it can operate without a power source.
Since it is small and lightweight, it is often used in mobile phones and the like that require high-density mounting of electronic component devices.

The electrical and mechanical connection between a device chip and its envelope in an electronic component device is becoming mainstream by a flip chip bonding method using metal bumps.

As a known example using such a flip chip bonding (or face down bonding) method, for example, "Surface acoustic wave device and its manufacturing method" disclosed in Japanese Patent Laid-Open No. 2001-94390.
There is.

The flip chip bonding method will be briefly described below, though not shown.
That is, basically, a bump is previously formed on a device chip by using a metal wire or the like, and this bumped device chip is formed on a surface of a package made of ceramics or the like by using a flip chip bonder. Mount on the pattern. Then, the bump metal and the wiring pattern are joined by simultaneously performing pressurization / heating / application of ultrasonic waves. This joining provides electrical and mechanical connection between the device chip and the package. afterwards,
Sealing is performed with the sealing resin, and the final electronic component device is completed.

[0006]

For example, in a SAW filter utilizing surface acoustic waves, the active electrode pattern formed on the surface of the device chip and configured to operate the surface waves is held in the hollow portion. When foreign matter such as water adheres to the electrode pattern held in the hollow state, the electrode may be corroded and may not function as a filter in some cases. Therefore, an electronic component device having a functional portion such as a SAW filter that does not like foreign matter from adhering must prevent foreign matter such as moisture from entering (or entering) from the outside. In order to prevent such foreign matter from entering / entering, sealing is performed.

That is, in the electronic component device having a structure in which the device chip and the package are connected by using the flip chip bonding method, it is necessary to protect the functional part of the device chip (the electrode pattern part of the SAW filter, etc.) from the outside (outside air). Yes, and for that, sealing is performed.

The encapsulating resin used for the encapsulation has a property of hermetically encapsulating the device chip and the package and a gap (SAW) between the device chip and the package.
The filter is required to have two characteristics, including the electrode pattern but hardly entering the hollow portion). Regarding the former hermetic sealing property, since the sealing resin needs to be completely adhered to the device chip and the package having different surface states / roughnesses, it is generally necessary that the resin has good wettability. On the other hand, with regard to the latter non-penetration characteristic, on the contrary, it is necessary that the wettability is poor because the sealing resin does not enter the gap between the device chip and the package.

In order to satisfy the two contradictory properties as described above, the viscosity and thixotropy (thixotro) of the sealing resin are generally used.
Py) is controlled and adjusted to obtain an appropriate sealing resin. However, the resin characteristics easily change due to changes with time and temperature changes, and it is difficult to control (or manage) the resin invasion property.

In general, a characteristic of a liquefied (or fluid) resin is a so-called capillary phenomenon, which facilitates "more" penetration into a narrow gap, and is manufactured using a flip chip bonding method. With SAW filters, hollow encapsulation presents a difficult problem.

The above problem will be described below with reference to a specific example. That is, the wiring pattern is formed on the package of the electronic component device such as the SAW filter. In the portion where the wiring pattern exists, the gap between the device chip and the package becomes narrower by the thickness of the wiring pattern. Capillary phenomenon is likely to occur in this narrowed portion. If the viscosity and thixotropy of the encapsulating resin are not strictly controlled, the liquefied (or fluid) encapsulating resin will greatly enter the narrowed portion due to the capillary phenomenon. When this resin enters, the resin adheres to the electrode pattern held in the hollow portion of the device chip, impairing its function. As a result, the electronic component device becomes a defective product.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electronic component device and a method for manufacturing the same which can prevent a malfunction due to the intrusion of a sealing resin.

[0013]

In an electronic component device (100) according to an embodiment of the present invention, a substrate composed of a device chip (1) having a predetermined functional portion (8) and a predetermined material (resin, ceramics, etc.). The device chip (1) and the substrate (3) are electrically conductive bumps (2) so that a predetermined space (7) including the functional portion (8) is formed between the device chip (1) and the substrate (3). Electrically and mechanically connected via. This electronic component device is configured such that the functional portion (8) of the device chip (1) is protected from the outside (outside air) by a protective material (5) such as resin. Here, between the end of the device chip (1) and the functional portion (8), the gap between the substrate (3) and the device chip (1) is wider than the gap in the functional portion (8). The protective material (5) is terminated in the area (9).

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a surface acoustic wave device will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining the internal structure of a surface acoustic wave device according to an embodiment of the present invention. FIG. 1A schematically illustrates a side cross section of the surface acoustic wave device, and FIG. 1B schematically illustrates a configuration of the surface acoustic wave device when viewed from above. .

A wiring pattern 4 is formed at a predetermined position on the substrate 3 made of resin or ceramics. Further, the surface acoustic wave element (device chip) 1 is configured by the comb-teeth-shaped electrode pattern (interdigital converter IDT) formed on the piezoelectric substrate 1.

A plurality of (four in the example of FIG. 1B) pads are connected to the electrode 8 via lead patterns. These pads (4) and predetermined portions (4 portions) of the wiring pattern 4 on the substrate 3 are arranged to face each other via the metal bumps 2 (4) made of gold or a gold alloy. . In this state, the metal bumps 2 between the device chip 1 and the substrate 3 are pressurized and heated, and ultrasonic waves are applied to partially melt them (flip chip bonding or face down bonding). When this pressurization / heating / application of ultrasonic waves is completed, the melted portion of the metal bump 2 is solidified. As a result, the pad (4
) And predetermined portions (4 places) of the wiring pattern 4 on the substrate 3 via the metal bumps 2 (4),
Electrically and mechanically connected. In this state, between the electrode 8 formed on the surface of the device chip 1 and the wiring pattern 4 formed on the surface of the substrate 3, a wide area corresponding to the arrangement / size of the metal bump 2 (deformed by bonding) is formed. A space of height / height (hollow portion 7) is secured.

After that, between the outer peripheral portion of the device chip 1 and the surface of the substrate 3 which are arranged so as to face the substrate 3 with the metal bumps 2 interposed therebetween, a suitable viscosity is obtained so that the gap 9 shown in FIG. And the sealing resin 5 having thixotropy is attached.
The gap 9 includes a depth corresponding to the thickness D of the wiring pattern 4 and a stepped portion 30 having a width (W1 to W4) from the edge of the wiring pattern 4 to the inner wall of the sealing resin 5. In other words, the wiring pattern 4 on the substrate 3 is not arranged in a region facing between the end portion of the device chip 1 and the electrode forming portion, and the device chip 1 and the substrate 3 are not arranged in that portion (gap 9). It is designed so that the gap between

With this arrangement, the sealing resin 5 can be prevented from flowing into the functional portion due to the capillary phenomenon, and the sealing resin 5 can be terminated at the portion where the gap is widened.

In this embodiment, the portion having a large gap has a gap of, for example, 50 μm as the sum of the height H of the bump and the height D of the wiring, and the capillary phenomenon does not occur and the resin penetration distance is greatly increased. It becomes smaller (depending on the resin, the entry distance becomes about ⅛ when the gap doubles, and the effect is extremely large). If the entry distance can be reduced, the risk of the liquefied resin 5 adhering to the electrode 8 can be eliminated.

Regarding the area of the large gap,
It can be appropriately adjusted according to the properties such as viscosity and thixotropy of the sealing resin used.

On the other hand, when the wiring was extended to a position facing the end of the surface acoustic wave element, the resin penetrated along the shape of the wiring due to the capillary phenomenon and adhered to the electrode of the surface acoustic wave element.

In the surface acoustic wave device of this embodiment, since the resin terminates in the region where the gap between the element and the substrate is large, a good sealing structure can be obtained without affecting the element characteristics.

FIG. 2 is a diagram for explaining the internal structure of an electronic component device according to another embodiment of the present invention. 2A schematically illustrates a side cross section of the electronic component device,
FIG. 2B schematically illustrates the configuration of the electronic component device when viewed from above.

In the embodiment shown in FIG. 2, a part (step portion 30) of the substrate 30 facing the gap 9 shown in FIG. 1 is dug down by laser cutting or the like, and a groove portion (step portion) 3 deeper than that in FIG.
The feature is that 0A is formed. In the embodiment of FIG. 2, to give a specific numerical example, the height H of the hollow portion 7 (height of the bump 2) is 25 μm, the thickness D of the wiring pattern 4 is 25 μm, and the depth of the substrate 3 to be dug is 30 μm
Can be In this case, the height D * from the surface of the wiring pattern 4 to the bottom of the groove portion 30A is 55 μm, and the width of the gap 9 is 80 μm. Since this 80 μm is larger than 50 μm in the case of FIG. 1, it is more difficult to cause the capillary phenomenon.

FIG. 3 is a diagram for explaining the internal structure of an electronic component device according to still another embodiment of the present invention. 3A schematically illustrates a side cross section of the electronic component device, and FIG. 3B schematically illustrates a configuration of the electronic component device when viewed from above. In the configuration of FIG.
As compared with the configuration described above, the width of the gap 9 is increased by the depth of the groove 30B. Therefore, the groove 30 in the configuration of FIG.
The widths W1b to W4b of B are the widths W1 to W4b in the configuration of FIG.
Even if it is narrower than W4, a sufficient resin entry preventing effect can be obtained.

FIG. 4 is a diagram for explaining the internal structure of an electronic component device according to still another embodiment of the present invention. FIG. 4A schematically illustrates a side cross section of the electronic component device, and FIG. 4B schematically illustrates a configuration of the electronic component device when viewed from above. In FIG. 4, as in FIG. 3, a narrow groove 30C is provided at an intermediate position of the step portion 30 of FIG. Even with this structure, it is possible to obtain a sufficient resin entry preventing effect.

<Effects of the Embodiment> As described above, it is very difficult to control and control the viscosity and thixotropy of the encapsulating resin 5, and even if there are few disturbance factors, the wettability and the ingress property vary. To surface. Disturbance factors include the size of the gap between the substrate and the device chip, etc. The smaller this distance, the more difficult it was to prevent sudden resin intrusion due to the capillary phenomenon. In each of the embodiments of the present invention, the penetration of the sealing resin 5 is controlled by intentionally widening the gap distance. As a result, the characteristic specifications required for the sealing resin 5 can be relaxed, and it becomes possible to select more types of sealing resin in the actual manufacturing of the product. It also inevitably leads to an improvement in manufacturing yield,
It is possible to obtain an electronic component device that is small, thin, inexpensive, and has high reliability.

The present invention is not limited to the above embodiments, and various modifications and changes can be made at the stage of carrying out the invention without departing from the spirit of the invention. Also,
The respective embodiments may be combined as appropriate as much as possible, and in that case, the effect of the combination can be obtained.

Further, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of constituent elements disclosed in this application. For example, even if one or more constituent elements are deleted from all the constituent elements shown in the embodiment, if at least one of the effect of the present invention or the effect of implementing the present invention is obtained, the constituent element is The deleted configuration can be extracted as an invention.

[0031]

As described above, according to the present invention,
In an electronic component device that has an internal space and is resin-sealed,
It is possible to prevent malfunction due to the sealing resin entering the internal space.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an internal structure of an electronic component device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an internal structure of an electronic component device according to another embodiment of the present invention.

FIG. 3 is a diagram illustrating an internal structure of an electronic component device according to still another embodiment of the present invention.

FIG. 4 is a diagram illustrating an internal structure of an electronic component device according to still another embodiment of the present invention.

[Explanation of symbols]

1 ... Device chip; 2 ... Metal bump (conductive bump); 3 ... Substrate (package); 4 ... Wiring pattern; 5
... Encapsulating resin; 7 ... Hollow part; 8 ... Electrode pattern (for example, functional part of interdigital converter IDT; comb-teeth-shaped electrode pattern, etc.); 9 ... Gap; 30 ... Step part (contour side of device chip 1) ); 30A to 30F ... Various groove (step) portions; 100 ... Electronic component device (such as a surface acoustic wave filter device).

Claims (6)

[Claims] 1. The device chip and the substrate are electrically conductive so that a predetermined space including the functional portion is formed between a device chip having the predetermined functional portion and a substrate made of a predetermined material. In an electronic component device that is electrically and mechanically connected via a conductive bump, and is configured such that the functional portion of the device chip is protected from the outside by a protective material, the end portion of the device chip and the An electronic component device having a region between the functional portion and the substrate and a device chip in which a gap between the substrate and the device chip is wider than the gap in the functional portion, and the protective material is terminated in the region. 2. The width of the widened portion in the direction along the surface of the substrate is determined to be a necessary size from the viewpoint of preventing the protective material from entering the space portion. The device according to claim 1. 3. A predetermined wiring pattern is provided on the surface of the substrate facing the front space, and the wiring pattern is formed in the portion where the gap between the substrate surface and the device chip surface is widened. The device according to claim 1 or 2, wherein the device is configured so as to widen the gap in that part by not providing the device. 4. The functional portion of the device chip is composed of a surface acoustic wave filter having predetermined electric characteristics,
The device according to any one of claims 1 to 3, wherein the protective material is made of resin. 5. The device chip and the substrate are electrically conductive so that a predetermined space including the functional portion is formed between a device chip having the predetermined functional portion and a substrate made of a predetermined material. Electronic device connected electrically and mechanically via a conductive bump and sealing the outer periphery of the device chip and the substrate so that the functional portion is shielded from the external atmosphere by a protective material. In the manufacturing method of (1), there is an area between the end portion of the device chip and the functional portion in which the gap between the substrate and the device chip is wider than the gap in the functional portion, and the protective material terminates in the area. And a method for manufacturing an electronic component device. 6. The gap between the substrate surface and the device chip surface is configured to be widened by cutting the surface of a part of the substrate and / or the device chip. Item 5. The method according to Item 5.