Elastic wave device and detection device therefor

Abstract

The utility model relates to an elastic wave device and a detection device thereof. The elastic wave device comprises a packaging substrate, a device chip and a sealing part, and the packaging substrate is square or rectangular; the device chip is jointed on the packaging substrate in an inverted manner; the packaging substrate is provided with a functional surface, the packaging substrate is provided with a sealing part, the sealing part is provided with a closed internal space between the functional surface of the device chip and the packaging substrate, and the four side surfaces of the packaging substrate are provided with inclined parts, so that the inclined parts of the packaging substrate protrude out of the sealing part. By pressing the elastic wave device to apply pressure to the test substrate, a defective product with poor contact of a pad bump is misjudged as a qualified product, so that the detection accuracy of the elastic wave device is relatively low, and the detection accuracy of the yield of the elastic wave device is improved.

Description

Technical Field

[0001] The present application relates to the field of packaging structures of elastic wave devices, and in particular to an elastic wave device and a detection device thereof. Background Art

[0002] Elastic wave devices are often used as frequency filters in mobile communication equipment and the like.

[0003] The common structure of an elastic wave device is a packaging unit that flip-chip bonds the device chip to a rectangular packaging substrate, while encapsulating the device chip together with the packaging substrate while leaving a closed space between the functional surface of the device chip and the packaging substrate. An example of a cross-sectional view of an elastic wave device is described in the prior art document (Japanese Patent Application Laid-Open No. 2022-013094). Figure 3 , and is also shown in FIG6(c) of the present application.

[0004] The elastic wave device has a rectangular parallelepiped shape as shown in FIG6(a) and has a plurality of external connection terminals on the back surface as shown in FIG6(b).

[0005] In the process of inspecting the high-frequency characteristics of elastic wave devices before shipment, Figure 7 The adsorption head shown vacuum adsorbs the elastic wave device from the through hole and presses the elastic wave device onto the detection circuit substrate for inspection.

[0006] Figure 8 This is a cross-sectional view of a defective elastic wave device in the prior art, as shown in FIG. Figure 8 As shown in the cross-sectional view, the pad bumps formed on the chip rarely have poor contact with the chip connection electrode pads on the package substrate.

[0007] As pad bumps for acoustic wave devices, gold bumps with heights of 15 to 25 μm are often used. However, since sealing requires space on the functional surface, it is difficult to secure the pad bumps with resin, as is done with conventional semiconductor devices. Consequently, variations in the thickness of the package substrate can result in bumps with insufficient fixing strength, which can lead to poor contact due to vibrations.

[0008] This is because during the high-frequency characteristic inspection process of the elastic wave device before shipment, it must be judged as a defective product and cannot be shipped.

[0009] Existing elastic wave devices are in the shape of a cuboid with a rectangular cross-section. During the inspection process, pressure is applied to the measurement circuit substrate from the upper surface of the elastic wave device to press the adsorption head, and inspection is performed while obtaining reliable contact between the elastic wave device and the measurement circuit substrate through the anisotropic conductive rubber.

[0010] Anisotropic conductive rubber has a structure in which a plurality of metal wirings are densely embedded in a rubbery, elastic resin. When pressure is applied from above, the metal wires deform, thereby ensuring contact.

[0011] Figure 9 This is a schematic diagram of the structure for testing elastic wave devices in the prior art (the elastic wave device is not pressed onto the test unit), showing the structure before a defective elastic wave device with poor contact having a solder bump is adsorbed by an adsorption head and pressed onto a measuring circuit substrate for inspection.

[0012] However, due to this pressure, e.g. Figure 10 As shown, the upper surface of the sealing portion of the elastic wave device formed of resin was slightly deformed, causing the bumps and the package substrate, which were originally not in contact, to be connected together, resulting in erroneous judgment as non-conforming products.

[0013] Adsorption on the upper surface of an elastic wave device may occur not in the center but near the periphery. However, the resin used for sealing has a certain elasticity, so the same phenomenon may occur.

[0014] In the above-mentioned inspection process of the high-frequency characteristics of elastic wave devices before shipment, pressure is applied to the test substrate by pressing the elastic wave device. This may cause defective products with poor bump contact to be mistakenly judged as qualified products, resulting in low accuracy in elastic wave device inspection. There is currently no suitable solution. Utility Model Content

[0015] The utility model solves the following problem: in the inspection process of the high-frequency characteristics of elastic wave devices before leaving the factory, pressure is applied to the test substrate by pressing the elastic wave device, which may mistakenly judge defective products with poor bump contact as qualified products, resulting in low accuracy in the yield detection of elastic wave devices.

[0016] In the first aspect, the utility model provides an elastic wave device, including a packaging substrate, a device chip, and a sealing portion, wherein the packaging substrate is square or rectangular; the device chip is flip-chip bonded to the packaging substrate; the sealing portion has a closed internal space between the functional surface of the device chip and the packaging substrate, and the four side surfaces of the packaging substrate have inclined portions, so that the inclined portions of the packaging substrate protrude from the sealing portion.

[0017] In some embodiments, the inclined portion is continuously formed on a side surface of the sealing portion and a side surface of the packaging substrate.

[0018] In some embodiments, the angle between the inclined portion and the bottom surface of the elastic wave device is in the range of 45 degrees to 75 degrees;

[0019] Alternatively, the angle between the side surface of the packaging substrate and the bottom surface of the elastic wave device is in the range of 45 degrees to 75 degrees, and the angle between the side surface of the sealing portion and the bottom surface of the elastic wave device is in the range of 80 degrees to 90 degrees.

[0020] In some embodiments, the inclined portion is continuously formed on a side surface of the sealing portion above the central region in the height direction and a side surface of the sealing portion below the central region in the height direction.

[0021] In some embodiments, the angle between the side surface of the sealing portion above the central region in the height direction and the bottom surface of the elastic wave device is in the range of 80 degrees to 90 degrees;

[0022] An angle between a side surface of the sealing portion below the center region in the height direction and the bottom surface of the elastic wave device is in a range of 45 degrees to 75 degrees.

[0023] In some embodiments, the package substrate includes an external connection terminal on a back surface of one side for connecting to an external circuit; and the package substrate includes an electrode pad on one side;

[0024] The functional surface of the device chip includes a pad bump, and the pad bump is connected to the electrode pad.

[0025] In a second aspect, the present application provides a detection device suitable for detecting the elastic wave device described in the first aspect, comprising a fixing unit and a testing unit;

[0026] The fixing unit is used to fix the elastic wave device on the testing unit; the testing unit is used to detect the frequency characteristics of the elastic wave device; wherein, when the elastic wave device is tested, the fixing unit only contacts the side surface of the packaging substrate of the elastic wave device.

[0027] The fixing unit includes an adsorption head, one side of the adsorption head has a frame-shaped extension portion, and the inner side of the front end of the frame-shaped extension portion is in contact with the entire circumference of the side surface of the packaging substrate; the center of one side of the adsorption head has a through hole, which is used to form a vacuum environment in the frame-shaped extension portion to adsorb the elastic wave device.

[0028] The test unit includes a connecting subunit, a test circuit, and a test substrate; the test circuit is formed on a functional surface of the test substrate; and the connecting subunit is connected to the elastic wave device and the test circuit respectively.

[0029] The connecting subunit is composed of rubber and metal wiring; the metal wiring is located in the rubber; one end of the metal wiring is connected to the elastic wave device, and the other end of the metal wiring is connected to the test circuit.

[0030] In the present application, since the side surface of the packaging substrate in the elastic wave device is formed by an inclined surface, the adsorption head will not apply pressure to the sealing resin. Therefore, defective elastic wave devices with an inclined portion of the above-mentioned packaging substrate will not be mistakenly judged as qualified products, and defective elastic wave devices will not be mistakenly shipped out of the factory, thereby solving the problem of low accuracy in elastic wave device detection when the elastic wave device is undergoing the high-frequency characteristics inspection process, and improving the detection accuracy of the elastic wave device.

[0031] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0033] 1( a ), 1( b ), and 1( c ) are respectively an oblique upper perspective view, an oblique lower perspective view, and a cross-sectional view of an elastic wave device according to a first embodiment of the present invention.

[0034] Figure 2 The figure is a schematic structural diagram of a fixing unit of the elastic wave device detection device of the present invention.

[0035] Figure 3 This is a schematic structural diagram of testing the elastic wave device of the first embodiment of the present invention.

[0036] 4( a ), 4( b ), and 4( c ) are respectively an oblique upper perspective view, an oblique lower perspective view, and a cross-sectional view of an elastic wave device according to a second embodiment of the present invention.

[0037] Figure 5 This is a schematic structural diagram of testing the elastic wave device of the second embodiment of the present invention.

[0038] 6( a ), 6 ( b ), and 6 ( c ) are respectively an oblique upper perspective view, an oblique lower perspective view, and a cross-sectional view of a conventional elastic wave device that is a good product.

[0039] Figure 7 The figure is a schematic structural diagram of a fixing unit of a detection device for elastic wave devices in the prior art.

[0040] Figure 8 This is a cross-sectional view of a defective elastic wave device in the prior art.

[0041] Figure 9 This is a schematic diagram of the structure of testing an elastic wave device in the prior art (the elastic wave device is not pressed onto the test unit).

[0042] Figure 10 This is a schematic diagram of the structure of testing an elastic wave device in the prior art (the elastic wave device is not pressed onto the test unit).

[0043] Figure: 100, elastic wave device; 110, sealing portion; 120, package substrate; 120b, opposite side of one surface of the package substrate; 130, external connection terminal; 140, bump pad; 150, device chip; 150a, functional surface of the device chip; 160, electrode pad; 200, suction head; 200a, through-hole; 310, rubber; 320, metal wiring; 330, test substrate. DETAILED DESCRIPTION

[0044] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0045] Unless otherwise defined, the technical terms or scientific terms involved in this application should have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "an", "a", "the", "these" and the like in this application do not indicate quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" involved in this application refers to two or more. "And / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. Generally, the character " / " indicates that the related objects are in an "or" relationship. The terms "first," "second," "third," etc. used in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0046] The following is a diagram of Figure 10 The elastic wave device of the present invention will be described.

[0047] First embodiment

[0048] Figures 1(a), 1(b), and 1(c) are, respectively, an oblique upper perspective view, an oblique lower perspective view, and a cross-sectional view of the elastic wave device according to the first embodiment of the present invention. As shown in the figures, the elastic wave device 100 has a rectangular or square shape with a length and width of approximately 1 mm to 2 mm when viewed from above, and a thickness of approximately 0.4 mm to 0.6 mm when viewed from a cross-sectional view. The elastic wave device 100 includes a package substrate 120, a device chip 150, and a sealing portion 110. The package substrate 120 is square or rectangular; the device chip 150 is flip-chip bonded to the package substrate 120; the sealing portion 110 defines a sealed internal space between a functional surface 150a of the device chip 150 and the package substrate 120; and the four side surfaces of the package substrate 120 have inclined portions that protrude beyond the sealing portion 110.

[0049] Specifically, the constituent material of the sealing portion 110 is resin, and the elastic wave device 100 has a rectangular shape when viewed from above; the functional surface 150a of the device chip 150 includes a solder pad bump 140, which is connected to the electrode pad 160 on the packaging substrate 120 through the solder pad bump 140, and the sealing portion 110 is used to ensure the sealing of the internal space on the functional surface 150a of the device chip 150.

[0050] The device chip 150 has a plurality of resonators with comb-tooth electrodes arranged on a piezoelectric body made of lithium tantalate or lithium niobate, and also has a plurality of electrode pads (not shown) for connecting to the pad bumps 140, and wiring for electrically connecting the above devices.

[0051] On the opposite side 120 b of one surface of the package substrate 120 , that is, the bottom surface of the elastic wave device 100 , there are a plurality of external connection terminals 130 for connecting to an external circuit.

[0052] The four side surfaces of the package substrate 120 have inclined portions. Specifically, the inclined portions are continuously formed on the side surfaces of the sealing portion 110 and the side surfaces of the package substrate 120. That is, the side surfaces of the elastic wave device 100 (the side surfaces of the package substrate 120 and the side surfaces of the sealing portion 110) are all inclined. As shown in FIG1(c), the angle formed by the side surfaces of the package substrate 120 and the side surfaces of the sealing portion 110 relative to the bottom surface of the elastic wave device is uniformly within a range of 45 degrees to 75 degrees. It should be noted that in other embodiments, the angle between the side surfaces of the package substrate and the bottom surface of the elastic wave device remains within a range of 45 degrees to 75 degrees, but the angle between the side surfaces of the sealing portion and the bottom surface of the elastic wave device can also be within a range of 80 degrees to 90 degrees.

[0053] Second embodiment

[0054] Figures 4(a), 4(b), and 4(c) are, respectively, an oblique upper perspective view, an oblique lower perspective view, and a cross-sectional view of an elastic wave device according to a second embodiment of the present invention. As shown in the figures, dashed line AA represents the height midline of sealing portion 110 perpendicular to the horizontal plane, i.e., the center region of sealing portion 110 in the height direction. The inclined portion of this second embodiment is continuously formed on the side surfaces of sealing portion 110 above the center region in the height direction and on the side surfaces of sealing portion 110 below the center region in the height direction.

[0055] Specifically, the angle of the inclined portion of the side surface of package substrate 120 in elastic wave device 100 is within the same range as that of the inclined portion in the first embodiment, but the upper portion of the central region of the side surface of sealing portion 110 is formed to be closer to vertical. In cross-sectional view 4(c), the angle of the side surface of sealing portion 110 above the central region relative to the bottom surface of the elastic wave device is between 80 degrees and 90 degrees, while the angle of the side surface of sealing portion 110 below the central region relative to the bottom surface of the elastic wave device is between 45 degrees and 75 degrees.

[0056] The rest of the structure of the elastic wave device of the second embodiment is the same as that of the elastic wave device of the first embodiment.

[0057] The utility model also provides a detection device suitable for detecting the elastic wave devices of the first embodiment and the second embodiment.

[0058] The elastic wave device of this embodiment includes a fixing unit and a testing unit; the fixing unit is used to fix the elastic wave device 100 on the testing unit; the testing unit is used to detect the frequency characteristics of the elastic wave device 100; wherein, when the elastic wave device 100 is tested, the fixing unit only contacts the side of the packaging substrate 120 of the elastic wave device 100.

[0059] Figure 2 This is a schematic structural diagram of the fixing unit of the elastic wave device detection device of the present invention, as shown in FIG. Figure 2 As shown, the fixing unit of the detection device of the present invention is an adsorption head 200. When inspecting high-frequency characteristics, the adsorption head used adsorbs the elastic wave device from the top.

[0060] Specifically, one side of the adsorption head 200 has a frame-shaped extension portion, and the inner side of the front end of the frame-shaped extension portion is in contact with the entire circumference of the side surface of the packaging substrate 120; the center of one side of the adsorption head has a through hole 200a, which is used to form a vacuum environment in the frame-shaped extension portion to adsorb the elastic wave device 100.

[0061] The test unit includes a connecting subunit, a test circuit and a test substrate; the test circuit is formed on a functional surface of the test substrate; and the connecting subunit is connected to the elastic wave device and the test circuit respectively.

[0062] The connecting subunit is composed of rubber and metal wiring; the metal wiring is located in the rubber; one end of the metal wiring is connected to the elastic wave device, and the other end of the metal wiring is connected to the test circuit.

[0063] Figure 3 This is a schematic structural diagram of testing the elastic wave device of the first embodiment of the present invention. Figure 3 In the embodiment, the connection subunit is composed of rubber 310 and metal wiring 320 , the formed connection subunit has anisotropy, and the test circuit is formed on the functional surface of the test substrate 330 .

[0064] like Figure 3 As shown, the inner side of the front end of the adsorption head 200 contacts the side surface with the inclined portion of the packaging substrate 120 in the elastic wave device, pressing it downward.

[0065] Since all four sides of the packaging substrate 120 are composed of inclined portions, the inner front end of the adsorption head 200 can contact the entire circumference of the side of the packaging substrate 120, and can reliably adsorb the elastic wave device by vacuum suction from the through hole 200a.

[0066] Because the seal is not pressed, elastic wave devices with poor pad bump contact will not be judged as defective due to the pad bump contacting the chip connection electrode pads under pressure, and thus will not be shipped. Therefore, the elastic wave device structure of the first embodiment solves the problem of low elastic wave device inspection accuracy during the high-frequency characteristics inspection process, thereby improving the accuracy of elastic wave device inspection.

[0067] Figure 5 This is a schematic diagram of the structure of the elastic wave device of the second embodiment of the present invention. Figure 5 As shown, because the seal is not pressed during the inspection process, elastic wave devices with poor contact between the pads and bumps are not judged as qualified. Therefore, the elastic wave device structure of the second embodiment solves the problem of low elastic wave device inspection accuracy during the high-frequency characteristics inspection process, thereby improving the accuracy of elastic wave device inspection.

[0068] Furthermore, the inclined side surface can make the sealing portion of the elastic wave device thicker, thereby improving the reliability of the elastic wave device, especially its moisture resistance.

[0069] Regarding other gain effects of the above-mentioned first and second embodiments, there is also the effect that, when a plurality of elastic wave devices having inclined portions are densely arranged on the front-end module, resin can flow more easily between the elastic wave devices compared to existing elastic wave devices having a rectangular shape.

[0070] It should be noted that, in the illustrated example, one device chip 150 is mounted on the packaging substrate 120, and in other embodiments, the same applies to elastic wave devices and elastic wave device modules in which multiple device chips 150 are mounted on the packaging substrate 120; in the illustrated example, the number of solder pad bumps 140 is 2, and in other embodiments, there may also be more solder pad bumps; in the embodiment of the present invention, an example of a device chip 150 having a resonator with comb-tooth electrodes is described, and in other embodiments, it may also be a device chip having a thin film piezoelectric resonator that utilizes vibration in the thickness direction of the device.

[0071] The expressions and terms used in the present invention are for illustrative purposes only and should not be considered as limiting. As used herein, the use of "include," "have," "have," "comprises," and their variations means including the following items, their equivalents, and additional items.

[0072] The term "embodiment" as used in this application refers to specific features, structures, or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily mean that the embodiment is the same, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is understood, either explicitly or implicitly, by those skilled in the art that the embodiments described in this application can be combined with other embodiments when there is no conflict.

[0073] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person of ordinary skill in the art may make variations, modifications, and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. An elastic wave device comprising a packaging substrate, a device chip, and a sealing portion, wherein the packaging substrate is square or rectangular; the device chip is flip-chip bonded to the packaging substrate; and the sealing portion has a closed internal space between a functional surface of the device chip and the packaging substrate, characterized in that: The four side surfaces of the packaging substrate have inclined portions, and the inclined portions of the packaging substrate protrude from the sealing portion.

2. The elastic wave device according to claim 1, wherein The inclined portion is continuously formed on a side surface of the sealing portion and a side surface of the packaging substrate.

3. The elastic wave device according to claim 2, wherein: The angle between the inclined portion and the bottom surface of the elastic wave device is in the range of 45 degrees to 75 degrees; Alternatively, the angle between the side surface of the packaging substrate and the bottom surface of the elastic wave device is in a range of 45 degrees to 75 degrees, and the angle between the side surface of the sealing portion and the bottom surface of the elastic wave device is in a range of 80 degrees to 90 degrees.

4. The elastic wave device according to claim 1, wherein The inclined portion is continuously formed on a side surface of the sealing portion above the central region in the height direction and a side surface of the sealing portion below the central region in the height direction.

5. The elastic wave device according to claim 4, wherein: The angle between the side surface of the sealing portion above the central region in the height direction and the bottom surface of the elastic wave device is in the range of 80 degrees to 90 degrees; An angle between a side surface of the sealing portion below the central region in the height direction and the bottom surface of the elastic wave device is in a range of 45 degrees to 75 degrees.

6. The elastic wave device according to claim 1, wherein The package substrate includes an external connection terminal on the opposite side of one side for connecting to an external circuit; the package substrate includes an electrode pad on one side; The functional surface of the device chip includes a pad bump, and the pad bump is connected to the electrode pad.

7. A detection device suitable for detecting the elastic wave device according to any one of claims 1 to 6, characterized in that: Including fixed unit and test unit; The fixing unit is used to fix the elastic wave device on the testing unit; the testing unit is used to detect the frequency characteristics of the elastic wave device; wherein, when the elastic wave device is tested, the fixing unit only contacts the side surface of the packaging substrate of the elastic wave device.

8. The detection device according to claim 7, characterized in that The fixing unit includes an adsorption head, one side of the adsorption head has a frame-shaped extension portion, and the inner side of the front end of the frame-shaped extension portion is in contact with the entire circumference of the side surface of the packaging substrate; the center of one side of the adsorption head has a through hole, which is used to form a vacuum environment in the frame-shaped extension portion to adsorb the elastic wave device.

9. The detection device according to claim 7, characterized in that: The test unit includes a connecting subunit, a test circuit, and a test substrate; the test circuit is formed on a functional surface of the test substrate; and the connecting subunit is connected to the elastic wave device and the test circuit respectively.

10. The detection device according to claim 9, characterized in that: The connecting subunit is composed of rubber and metal wiring; the metal wiring is located in the rubber; one end of the metal wiring is connected to the elastic wave device, and the other end of the metal wiring is connected to the test circuit.

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