Module comprising elastic wave device
Technical Field
The present invention relates to an electronic component, and more particularly to a module including an elastic wave device that includes an elastic wave device requiring a hollow structure.
Background
In a communication device terminal such as a mobile phone terminal or a portable information terminal, an RF (radio frequency) device such as a filter or a duplexer tends to be as follows: these are integrated with a front-end module, a power amplifier, or the like to achieve miniaturization, and thus configured as a multi-chip module. In the multi-chip module, a plurality of chip components are mounted on 1 common substrate and sealed with a molding resin.
In an Acoustic Wave device requiring a hollow structure, as in the case where a chip component mounted on the substrate constitutes a SAW (Surface Acoustic Wave) filter or a BAW (Bulk Acoustic Wave) filter, a hollow portion has been conventionally formed in each of the Acoustic Wave device chips (see, for example, japanese patent application laid-open No. 2002-510929). That is, as shown in fig. 5(a), the conventional acoustic wave device 50 includes a dedicated substrate 51 for an acoustic wave device, a bare chip 52, and a hollow portion 56. A dam (dam)54 for forming a hollow 56 is provided between the dedicated substrate 51 and the bare chip 52 of the acoustic wave device, and the dedicated substrate 51 and the bare chip 52 are electrically and mechanically connected by a connection portion 53. The dam portion 54 prevents the sealing resin 55 provided in each elastic wave device 50 from penetrating into the hollow portion 56 and entering the electrode arrangement portion (the periphery where the electrodes 52a are arranged) of the bare chip 52. When the acoustic wave device 50 is connected to and mounted on the common substrate 57 via the connection portion 58 together with another acoustic wave device 50 or another active element or passive element that does not require a hollow structure, the acoustic wave device is covered with a sealing resin not shown.
If a chip having a hollow portion 56 in each of the elastic wave devices 50 is mounted on a common substrate 57 together with other components and modularized, which constitutes the structure of the conventional elastic wave device, there are the following advantages. First, as for convenience of the manufacturing process, it is possible to use a manufacturing apparatus or a manufacturing line for mounting a chip on the common substrate 57 after the component such as the acoustic wave device is first manufactured into the chip, and manufacturing is easily performed even in an environment where there is no multi-type and multi-functional mounting apparatus. Second, since it is easy to grasp or secure the characteristics of individual parts as the elastic wave device 50, it is easy to perform module design. Third, when a module failure occurs, it is easy to analyze where the failure has occurred, and the analysis of which manufacturer or manufacturing unit managed the failure is relatively clear.
Disclosure of Invention
The present invention provides a module including an elastic wave device that requires a hollow structure, the module including:
a substrate having a plurality of conductive pads formed on a component mounting surface;
at least one elastic wave device having an electrode arrangement portion on a surface of the substrate opposite to the component mounting surface and having a conductive pad electrically connected to the conductive pad;
at least one flip chip assembly device other than the elastic wave device, having a conductive pad electrically connected to the conductive pad of the component mounting surface of the substrate; and
and dams that are provided between the component mounting surface of the substrate and a peripheral portion of the acoustic wave device, form hollow portions that surround the electrode placement portions between the respective acoustic wave devices and the substrate, and prevent sealing resin from penetrating into the hollow portions from the outside.
A module according to the present invention includes an elastic wave device that requires a hollow structure, and includes:
a substrate having a plurality of conductive pads formed on a component mounting surface;
a plurality of elastic wave devices each having an electrode arrangement portion on a surface of the substrate facing the component mounting surface and a conductive pad electrically connected to the conductive pad; and
a dam portion provided between the component mounting surface of the substrate and a peripheral portion of the elastic wave device, forming a hollow portion surrounding the electrode arrangement portion between each elastic wave device and the substrate, and preventing a sealing resin from penetrating into the hollow portion from the outside; and is
The elastic wave devices are disposed adjacent to each other, and a common portion of the dam portion is provided to be shared by the adjacent elastic wave devices.
The module including an elastic wave device according to the present invention further includes at least one flip chip assembly device other than the elastic wave device, the flip chip assembly device having a conductive pad electrically connected to the conductive pad on the component mounting surface of the substrate.
In the module including an elastic wave device according to the present invention, the dam portion is bonded only to a region where a surface of the substrate opposing surface of the elastic wave device is non-metallic.
In the module including an elastic wave device according to the present invention, the dam is formed of a photosensitive resin, and the photosensitive resin of the dam has adhesiveness after patterning.
A module including an elastic wave device according to the present invention includes a plurality of elastic wave devices, and a planar shape of a hollow portion formed in the plurality of elastic wave devices is such that at least a part of the hollow portions have mutually different shapes.
The module including an elastic wave device according to the present invention includes a plurality of elastic wave devices, and the planar shapes of hollow portions formed in the plurality of elastic wave devices have the same shape.
In the module including an elastic wave device according to the present invention, the plurality of elastic wave devices are mounted adjacent to each other on the substrate, and the interval between the adjacent elastic wave devices is 100 μm or less.
In the module including an elastic wave device according to the present invention, a distance of 20 μm or more is provided between a chip end of the elastic wave device and an inner end of the dam in a region in contact with the dam, and a gap formed between the dam and the elastic wave device is zero or less than one tenth of a radius of filler particles of a sealing resin.
In the module including an elastic wave device according to the present invention, the elastic wave device and the flip chip assembly device are disposed adjacent to each other except for the elastic wave device, and an underfill material is filled between the flip chip assembly device and the substrate, the underfill material having a region in contact with a dam portion disposed between the adjacent elastic wave device and the substrate.
In the module including an elastic wave device according to the present invention, a planar shape of an edge portion of the dam portion on an assembled device side of the flip chip adjacent to the elastic wave device is a concave-convex shape, and at least a part of the edge portion of the dam portion in the concave-convex shape is located further outside than a chip end of the assembled device of the adjacent flip chip.
In the module including an elastic wave device according to the present invention, a heat dissipation mechanism is provided on a surface of the flip chip mounted device opposite to the substrate facing surface.
Problems to be solved by the invention
On the other hand, the conventional elastic wave device 50 has the following problems. First, since the elastic wave device dedicated substrate 51 is interposed between the bare chip 52 and the common substrate 57 of the elastic wave device 50, a conduction path from the bare chip 52 to the common substrate 57 becomes long, and parasitic resistance, capacitance, and inductance, that is, parasitic impedance increase accordingly, and performance deteriorates. Second, when viewed from the whole multi-chip module, since the substrates are two layers of the substrate 51 dedicated to the acoustic wave device and the common substrate 57, and the sealing resin is also two layers of the sealing resin 55 for the acoustic wave device and the sealing resin for the module, not shown, the cost of the process cost and the material cost increases. Third, since the acoustic wave device 50 is configured by combining the dedicated substrate 51 and the bare chip 52, the height H1 and the width W1 become large, which hinders miniaturization and thinning of the module, and tends to hinder high-density mounting.
In view of the above problems, an object of the present invention is to provide a module including an elastic wave device, which can achieve simplification of a structure, high-density mounting, and cost reduction, and also can reduce parasitic impedance, when the module is configured to include an elastic wave device requiring a hollow structure.
Means for solving the problems
As a first aspect, a module including an elastic wave device according to the present invention includes an elastic wave device requiring a hollow structure, and includes: a substrate having a plurality of conductive pads formed on a component mounting surface; at least one elastic wave device having an electrode arrangement portion on a surface of the substrate opposite to the component mounting surface and having a conductive pad electrically connected to the conductive pad; at least one flip chip assembly device other than the elastic wave device, having a conductive pad electrically connected to the conductive pad of the component mounting surface of the substrate; and dam portions provided between the component mounting surface of the substrate and peripheral portions of the elastic wave device, forming hollow portions between the elastic wave devices and the substrate so as to surround the electrode arrangement portions, and preventing a sealing resin from penetrating into the hollow portions from the outside.
In this aspect, since it is not necessary to interpose a substrate dedicated to the acoustic wave device between the acoustic wave device and the substrate on which the flip-chip assembly device is mounted, the electrical conduction path from the bare chip to the substrate is shortened, and accordingly, the impedance is reduced as compared with the case where a substrate is provided for each acoustic wave device, and the performance can be improved. Further, when the module including the acoustic wave device is viewed as a whole, the substrate is common to the acoustic wave device and the other flip-chip mounted devices, and the sealing resin is also common to them, so that the cost reduction of the process cost and the material cost can be achieved. Further, since the elastic wave device does not require a dedicated substrate, the module including the elastic wave device can be reduced in height and width, and the module including the elastic wave device can be reduced in size and thickness, and high-density mounting can be easily achieved.
A second aspect of a module including an elastic wave device according to the present invention is a module including an elastic wave device that requires a hollow structure, the module including an elastic wave device including: a substrate having a plurality of conductive pads formed on a component mounting surface; a plurality of elastic wave devices each having an electrode arrangement portion on a surface of the substrate facing the component mounting surface and a conductive pad electrically connected to the conductive pad; and dam portions provided between the component mounting surface of the substrate and peripheral portions of the elastic wave device, forming hollow portions surrounding the electrode arrangement portions between the elastic wave devices and the substrate, and preventing a sealing resin from penetrating into the hollow portions from outside; and the elastic wave devices are disposed adjacent to each other, and a common portion of the dam portion is provided to be shared by the adjacent elastic wave devices. Here, the common portion of the dam means a portion of the dam for 2 adjacent elastic wave devices and also serves as the dam for the 2 elastic wave devices.
In this aspect, since the common portion shared by the adjacent elastic wave devices is provided, the width of the region in which the dam portion is provided may be narrower than that in the case where 2 dam portions are arranged in the region in which the elastic wave devices are adjacent, and thus the elastic wave devices can be arranged close to each other. Therefore, the mounting space of the module including the acoustic wave device is reduced, and the module can be mounted in a compact and high-density manner. Further, since a dedicated substrate for each acoustic wave device is not required, the acoustic wave device can be thinned. Further, since it is not necessary to interpose a substrate dedicated to each acoustic wave device, the electrical conduction path from the bare chip to the substrate is shortened, and accordingly, the impedance is reduced as compared with the case where a substrate is provided for each acoustic wave device, and the performance can be improved. Further, since a dedicated substrate for each elastic wave device is not required, the cost reduction of the process cost and the material cost can be achieved.
A third aspect of the module including an elastic wave device according to the present invention is the module including an elastic wave device according to the second aspect including a plurality of elastic wave devices as described above, further including at least one flip chip assembly device other than the elastic wave device, the flip chip assembly device including a conductive pad electrically connected to the conductive pad on the component mounting surface of the substrate.
According to this aspect, the space reduction effect by using the common portion of the dam portion in the second aspect, the low-back effect by not requiring a substrate dedicated to the elastic wave device, and the impedance reduction effect by the first and second aspects can be obtained, and further cost reduction of the process cost and the material cost can be achieved by the effect of reducing the number of processes. In addition, further effects of miniaturization and high-density mounting are easily obtained.
In the above aspects, it is preferable that only a region of the elastic wave device having a non-metallic surface is bonded to the dam portion. In this case, the dam portion and the elastic wave device can be firmly bonded.
In each of the above embodiments, it is preferable that the dam is formed of a photosensitive resin, and the photosensitive resin has adhesiveness after patterning. In this case, the hollow portion can be easily patterned by using a photosensitive resin for the dam portion. Further, since the photosensitive resin has adhesiveness, the elastic wave device can be attached to the substrate and the dam portion can be adhered to the elastic wave device, and the attachment of the elastic wave device to the substrate is facilitated.
In the second and third aspects, the hollow portions formed corresponding to the plurality of elastic wave devices may have shapes when viewed in a direction perpendicular to the substrate, the shapes being different from each other and the shapes being the same. The morphology is selected corresponding to the shape or size of the elastic wave device.
In the above aspects, it is preferable that a plurality of elastic wave devices are mounted adjacent to each other on the substrate, and the interval between the adjacent elastic wave devices is 100 μm or less. In this case, further high-density mounting can be achieved.
In the above aspects, it is preferable that a region of the elastic wave device in contact with the dam has a distance of 20 μm or more from a chip end of the elastic wave device to an inner end of the dam, and a gap formed between the dam and the elastic wave device is zero or less than one tenth of a radius of filler particles of the sealing resin. In this case, the dam portion more preferably prevents the sealing resin from penetrating into the hollow portion.
In the above aspects, it is preferable that the elastic wave device and the flip chip assembly device other than the elastic wave device are disposed adjacent to each other with the hollow portion formed between the elastic wave device and the substrate, and an underfill material is filled between the flip chip assembly device and the substrate, and the underfill material is in contact with the dam portion of the elastic wave device. In this case, since the dam portion prevents the underfill material from penetrating into the hollow portion, the flip chip assembly device can be disposed close to the acoustic wave device.
In the above aspects, it is preferable that a planar shape of an edge portion of the dam portion on the device-mounted side of the flip chip adjacent to the acoustic wave device is a concave-convex shape, and at least a part of the edge portion of the dam portion in the concave-convex shape is located outside a chip end of the device-mounted device of the adjacent flip chip. In this case, since the gap between the flip-chip assembled device and the substrate is not closed by the dam due to the uneven shape of the edge of the dam, it is possible to prevent voids from being generated on the elastic wave device side when the underfill material penetrates between the flip-chip assembled device and the substrate due to a penetration phenomenon. Therefore, a good filling state of the underfill material can be obtained between the flip-chip assembled device and the substrate.
In the above aspects, it is preferable that a heat dissipation mechanism is provided on a surface of the flip-chip mounted device opposite to the substrate facing surface. In this case, the heat dissipation mechanism can obtain a heat dissipation effect of heat generated in the flip chip mounted device, thereby suppressing temperature rise.
Effects of the invention
According to the present invention, in a module including an acoustic wave device, it is possible to achieve miniaturization, low-back and high-density mounting of a package, performance improvement by reducing parasitic impedance, and cost reduction of process cost and material cost.
Drawings
Fig. 1 is a cross-sectional view showing an embodiment of a module including an elastic wave device according to the present invention.
Fig. 2 is a plan view showing a state before a sealing resin is applied to the module including the elastic wave device of fig. 1.
Fig. 3 is a plan view showing a pattern of dams in the module including the elastic wave device of fig. 1.
Fig. 4 is a partially enlarged sectional view of the module including the elastic wave device of fig. 1.
Fig. 5(a) is an example of a conventional module including an elastic wave device, and fig. 5(b) is a cross-sectional view of the module including an elastic wave device of fig. 1.
Fig. 6 is a plan view showing another example of the dam pattern in the module including an elastic wave device according to the present invention.
Fig. 7 is a cross-sectional view showing another embodiment of a module including an elastic wave device according to the present invention.
Fig. 8 is a plan view showing a state before a sealing resin is applied to the module including the acoustic wave device of fig. 7.
Fig. 9 is a partially enlarged sectional view of the module including the elastic wave device of fig. 7.
Fig. 10 is a plan view showing another example of the pattern of the dam portion in the module including an elastic wave device of fig. 7 in a state before the sealing resin is applied.
Fig. 11 is a cross-sectional view illustrating the function of the dam having the pattern of fig. 10.
Fig. 12 is a cross-sectional view showing a modification of the module including the elastic wave device of fig. 7.
Fig. 13 is a cross-sectional view showing another modification of the module including the elastic wave device of fig. 7.
Detailed Description
The present invention will be described in detail with reference to the drawings and embodiments, and it is noted that similar elements are denoted by the same reference numerals in the following description.
Fig. 1 and 2 show an embodiment of a module including an elastic wave device according to the present invention. The module 1 including the acoustic wave device according to the present embodiment shows an example in which 2 acoustic wave devices 3 are mounted on a substrate 2. The acoustic wave device 3 of the present embodiment is a surface acoustic wave device (SAW device) in which an IDT (Interdigital-Transducer) electrode 6 is formed on one surface of a piezoelectric body 5 formed of a piezoelectric material. For example, Lithium Tantalate (LT) or Lithium Niobate (LN) is used for piezoelectric body 5, and for example, Al, Cu, Ni, Au, W, Mo, or the like is used for IDT electrode 6. In the drawing, the IDT electrode 6 is shown in a simplified manner, but actually, a plurality of comb-shaped input-side and output-side electrodes and reflection electrodes are formed.
The substrate 2 is formed of a ceramic substrate or a laminated substrate, and in this example, an example of a laminated substrate having a planar conductor 8 inside is shown. A passive element such as a capacitor or an inductor may be formed inside the substrate 2. As shown in fig. 4, the component mounting surface 2a of the substrate 2 has a plurality of conductive pads 9. The surface of the substrate 2 opposite to the component mounting surface 2a is a mounting surface 2b of a mother substrate, not shown, and the mounting surface 2b has a conductive pad 10 electrically and mechanically connected to the mother substrate. The conductive pads 9 on the component mounting surface 2a and the conductive pads 10 on the mounting surface 2b are connected to each other via the internal conductors 8 or via conductors not shown.
The acoustic wave device 3 and the substrate 2 are electrically and mechanically connected via a plurality of connection portions 12. As shown in fig. 4, the connection portion 12 includes: a conductive pad 13 provided on the connection electrode 6a in the acoustic wave device 3; conductive pads 9 on the substrate 2; and a bump 14 for bonding the conductive pad 13 and the conductive pad 9. The bump 14 may use Au or solder, for example.
A sealing resin 16 for covering the mounted acoustic wave device 3 and the substrate 2 is formed on the substrate 2. The sealing resin 16 covers the elastic wave device 3 and the upper surface of the substrate 2, and functions as follows: the elastic wave device 3 is fixed to the substrate 2, and the elastic wave device 3 is prevented from being affected by dust or moisture, thereby improving the reliability of the module. The sealing resin 16 is a thermosetting resin such as an epoxy resin.
On the substrate 2, a dam 18 is formed before the elastic wave device 3 is connected and mounted by the connection portion 12. The dam 18 prevents the sealing resin 16 from penetrating into the electrode arrangement portion 3a of the acoustic wave device 3. The electrode arrangement portion 3a includes an electrode on the surface of the acoustic wave device and a surface on the periphery thereof on which the acoustic wave propagates. In the case of the surface acoustic wave device including the IDT electrode 6 as in the present embodiment, the electrode arrangement portion 3a includes a surface on the surface of the acoustic wave device, on which an elastic wave propagates, in the vicinity of the IDT electrode 6. In the case of a surface acoustic wave device having a reflector in the electrode, the periphery of the reflector is also included in the electrode arrangement portion 3 a. Therefore, as shown in fig. 3 and 4, the dam 18 is formed in a planar shape in which the missing portions 18a and 18b of the dam 18 are formed so as to surround the IDT electrode 6 and the connection portion 12 in a planar view in a region corresponding to the electrode arrangement portion 3a of the acoustic wave device 3 so as to face only the peripheral portion 3b of the acoustic wave device 3. As shown in fig. 1 and 2, a hollow portion 19 surrounding the electrode arrangement portion 3a is formed by the elastic wave device 3, the substrate 2, and the dam portion 18.
As the dam 18, a photosensitive resin is preferably used to facilitate patterning. The dam 18 is formed by applying a photosensitive resin to a sheet (not shown) as a material of the substrate 2, for example, and exposing the applied photosensitive resin layer to light while covering the portions other than the areas to be the cut portions 18a and 18b with a mask so as to form the cut portions 18a and 18b of the dam 18 shown in fig. 3. Then, the photosensitive resin layer is developed and heat-treated, whereby the dam 18 having the defective portions 18a and 18b is formed on the material (sheet) of the substrate 2. As the photosensitive resin to be the dam 18, a photosensitive resin having adhesiveness after patterning is preferably used from the viewpoint of enhancing the dam function of preventing the sealing resin from penetrating into the hollow portion 19. As the photosensitive resin having adhesiveness after patterning, an epoxy acrylate resin or a polyimide resin can be used.
By mounting the acoustic wave device 3 on the material (sheet) of the substrate 2 after the dam 18 is formed, as shown in fig. 1 and 2, the hollow portion 19 in which the electrode arrangement portion 3a of the acoustic wave device 3 is surrounded by the dam 18 is formed between the substrate 2 and the acoustic wave device 3. In order to form the hollow portion 19, the acoustic wave device 3 is mounted by a flip chip bonding machine, not shown, so that the peripheral portion 3b of the acoustic wave device 3 faces the edge portions of the cutout portions 18a and 18 b. This mounting is performed by bonding bumps 14 provided in advance on the acoustic wave device 3 to conductive pads 9 provided in advance on a wafer serving as the substrate 2.
The conductive pad 9 and the bump 14 are bonded, and the peripheral portion 3b of the acoustic wave device 3 is bonded to the photosensitive resin to be the dam portion 18. That is, by using a photosensitive resin having adhesiveness after patterning as the dam 18, the elastic wave device 3 can be adhered to the dam 18 simultaneously with the mounting of the elastic wave device 3 to the substrate 2.
As shown in fig. 5(b), the module 1 can be made smaller and thinner than the conventional module shown in fig. 5 (a). That is, in the conventional acoustic wave device 50, since the dedicated substrate 51 is required for each acoustic wave device 50, the width of the acoustic wave device 50 itself is also increased, and the space S1 between the bare chip 52 and the bare chip 52 of the acoustic wave device 50 must be made large. On the other hand, in the present embodiment, since the elastic wave devices 3 are mounted on the common substrate 2 in a bare chip state, the width of the elastic wave devices 3 themselves is also reduced, and the space S2 between the elastic wave devices 3 may be narrow. Therefore, in the case of the module of the present embodiment, the width W2 is smaller than the width W1 of the conventional module, and downsizing and high-density mounting can be achieved.
Further, as in the present embodiment, the common portion 18c of the dam portion 18 between the adjacent elastic wave devices 3 is shared by the adjacent elastic wave devices 3, whereby the space S2 can be further narrowed.
Further, although the dedicated substrate 51 is required for each acoustic wave device 50 in the conventional example, the height H2 of the entire module can be made thinner than the height H1 of the conventional example because the dedicated substrate 51 is not required in the present embodiment.
In the case of the conventional example, the conductor path from the connection portion 53 to the substrate 57 in the acoustic wave device 50 requires the conductor path arranged on the dedicated substrate 51 and the conductor path for the connection portion 58 from the dedicated substrate 51 to the common substrate 57. Therefore, the parasitic resistance, inductance, capacitance, that is, the parasitic impedance is reduced, and the characteristics of the module can be improved.
Further, in the case of the conventional example, the dedicated substrate 51 and the connection portion 58 for connecting the dedicated substrate 51 to the common substrate 57 are required, but in the case of the present invention, these are not required, so that the cost reduction of the process cost and the material cost can be realized.
Further, in the case of the module 1 of the present embodiment, the module design becomes easy. This is because: since the bare chips can be directly mounted on the substrate 2 even when the number of chips included in the module 1 is increased or the number of combinations of the types of chips is increased, the molding and sealing conditions by the sealing resin 16 are almost unchanged, and therefore, the number of development steps required for setting the process conditions is reduced. In addition, the lead time of product development can be shortened by facilitating the module design.
In the present embodiment, the dam 18 is preferably bonded to the acoustic wave device 3 only in a region where the surface of the piezoelectric body 5 of the acoustic wave device 3 is non-metallic, as shown in fig. 1 and 4, and not bonded to a metal layer such as the connection electrode 6a, from the viewpoint of firmly bonding the dam 18 to the acoustic wave device 3.
As described above, the dam 18 is preferably formed of a photosensitive resin, and the photosensitive resin has adhesiveness after patterning. By using the photosensitive resin for the dam 18 in this way, the patterning of the missing portions 18a and 18b of the dam 18 for forming the hollow portion 19 becomes easy. Further, since the photosensitive resin has adhesiveness, the elastic wave device 3 can be attached to the substrate and the elastic wave device 3 can be adhered to the dam 18 at the same time, and the attachment of the elastic wave device 3 to the substrate 2 is facilitated.
As shown in fig. 2 and 3, in the present embodiment, the planar shape of the hollow portion 19 formed corresponding to each of the plurality of elastic wave devices 3 is the same. Fig. 6 is an example in which hollow portions 19X and 19Y having different planar shapes are used depending on the shapes of the elastic wave devices 3X and 3Y, unlike the above-described example. In this way, the planar shape of the hollow portion is formed in the same shape or in different shapes depending on the planar shape of the acoustic wave device 3.
When a plurality of elastic wave devices 3 are mounted adjacent to each other as in the present embodiment, the space S2 (see fig. 5(b)) between the adjacent elastic wave devices 3 can be set to 100 μm or less. That is, the dam portion 18 is formed as the common portion 18c between the adjacent elastic wave devices 3, so that the portion of the width W3 of the common portion 18c can be easily formed as compared with the case where the elastic wave devices 3 are formed as separate regions. Therefore, the elastic wave device 3 can be mounted close to the space S2, and the space S2 is close to the close mounting limit of the flip chip mounter.
In the present embodiment, it is preferable that the width t (see fig. 2 and 4) of the region of the peripheral portion 3b of the acoustic wave device 3 in contact with the dam 18, that is, the distance from the chip end portion 3c of the acoustic wave device 3 to the inner end 18d of the dam 18 be 20 μm or more. The upper limit of the width t is a distance from the chip end 3c to a region where a metal layer such as the connection electrode 6a is formed.
Further, although the surface of the dam 18 facing the acoustic wave device 3 may have irregularities, it is preferable that even if a gap is formed between the dam 18 and the acoustic wave device 3 in this case, the gap is equal to or smaller than one tenth of the radius of the filler particles of the sealing resin 16. If such a relationship between the gap and the size of the filler particles is set, the dam 18 is more effective in preventing the sealing resin 16 from penetrating into the hollow portion 19.
Fig. 7 is a sectional view showing another embodiment of the module of the present invention, fig. 8 is a plan view thereof, and fig. 9 is a partially enlarged sectional view of fig. 7. This module is a module in which the elastic wave device 3 and the flip-chip assembly device 22 other than the elastic wave device 3 are formed on the same substrate 2. The flip-chip assembled device 22 of this example is shown as an amplifier as an active device constituting a duplexer in a mobile communication device.
The flip-chip assembled device 22 is electrically and mechanically connected to the substrate 2 via the connection portion 23. As shown in fig. 9, the connection portion 23 is formed by bonding the conductive pad 24 provided on the component mounting surface 2a of the substrate 2 and the conductive pad 26 provided on the connection electrode 25 provided on the substrate opposing surface of the flip-chip assembled device 22 by using the bump 27. Au or solder is used for the bump 27.
The dam 18 is formed by patterning a photosensitive resin, and has adhesiveness after patterning. As shown in fig. 7, a hollow portion 19 is formed between the elastic wave device 3 and the substrate 2 by the dam portion 18 so as to surround the electrode arrangement portion 3a of the elastic wave device 3. As shown in fig. 8, this example shows an example in which 2 elastic wave devices 3 are arranged adjacent to each other, and a common portion 18c of the dam portion 18 is formed between the 2 elastic wave devices 3 arranged adjacent to each other.
In this module, first, in a state where the substrate 2 is a wafer, regions 18e and 18f to be the missing portions of the dam portions 18 are formed by patterning a photosensitive resin so as to correspond to the elastic wave device 3 in order to form the hollow portions 19. The photosensitive resin is a material having adhesiveness after patterning. Next, the elastic wave device 3 is bonded to the substrate 2 by the connection portion 12 using a flip chip bonding machine, and thereby fixed to the substrate 2. At this time, the elastic wave device 3 is also bonded to the dam 18. At this time, as shown in fig. 8, the dam 18 is in a state in which the edge 18g provided between the elastic wave device 3 and the flip-chip assembled device 22 protrudes from the elastic wave device 3 toward the flip-chip assembled device 22 by a width indicated by g 1.
In this way, in a state where the acoustic wave device 3 is mounted on the substrate 2, the flip-chip assembly device 22 is fixed by being bonded to the substrate 2 by the connection portion 23. At this time, as shown in fig. 8, the flip-chip assembled device 22 is mounted so that a gap g2 is formed between the edge 18g of the dam 18 and the flip-chip assembled device 22. The gap g2 is provided to prevent formation of a void between the flip-chip assembled device 22 and the substrate 2. That is, after the flip-chip assembled device 22 is connected to the substrate 2 via the connection portion 23, the underfill material 21 having fluidity penetrates into the gap between the flip-chip assembled device 22 and the substrate 2 by its surface tension, and at this time, the gap g2 forms an escape path for air on the elastic wave device 3 side, and as a result, formation of voids can be prevented.
After the acoustic wave device 3 and the flip-chip assembly device 22 are mounted on the substrate 2 in this manner, the sealing resin 16 made of a thermosetting resin such as an epoxy resin is applied and the molding is performed with the sealing resin 16.
In this way, in the mounted state in which the acoustic wave device 3 is disposed adjacent to the flip-chip assembled device 22 and the underfill material 21 is filled between the flip-chip assembled device 22 and the substrate 2, the underfill material 21 contacts the edge 18g of the dam 18 of the acoustic wave device 3. Then, since the penetration of the underfill material 21 into the hollow portion 19 is prevented by the dam portion 18, the flip-chip assembled device 22 can be disposed close to the acoustic wave device 3.
Fig. 10 shows a preferable planar shape of the edge 18h of the dam 18 provided between the acoustic wave device 3 and the substrate 2 in the embodiment shown in fig. 7. The edge portion 18h has a concave-convex shape having a concave portion 30 recessed toward the acoustic wave device 3 side and a convex portion 31 protruding toward the flip-chip assembly device 22 side.
If the planar shape of the edge portion 18h of the dam portion 18 is formed into the uneven shape as described above, when the liquid underfill material 21 is filled between the substrate 2 and the flip chip assembly device 22 by the penetration phenomenon, as shown in fig. 11, an air passage as shown by an arrow 32 is easily secured between the recess 30 of the edge portion 18h and the flip chip assembly device 22, and the formation of voids is reliably prevented. That is, even when the interval between the acoustic wave device 3 and the flip-chip assembled device 22 is slightly deviated and the flip-chip assembled device 22 is mounted close to the acoustic wave device 3, the air passage is reliably formed when the underfill material 21 is filled due to the presence of the concave portion 30. The waveform of the edge 18h may be formed into a square shape, instead of a smooth curved shape as shown in the figure.
Fig. 12 is a sectional view showing still another embodiment of the module of the present invention. In the present embodiment, a heat sink structure is formed in which a heat sink 33 as a heat dissipation mechanism is provided on the surface of the flip-chip assembled device 22 on the opposite side to the substrate opposing surface. The heat sink 33 is made of a metal having good thermal conductivity such as Al, Cu, Ag, or the like, and preferably a metal plate having a plurality of fins. By providing such a heat sink structure, a heat radiation effect of heat generated in the flip-chip mounted device 22 can be obtained, and temperature rise can be suppressed.
Fig. 13 shows a case where the sealing resin 16 is filled between the substrate 2 and the flip-chip assembled device 22 instead of using the underfill material 21, and in this case, the edge 18g of the dam 18 used in the elastic wave device 3 is in contact with the sealing resin 16 on the flip-chip assembled device 22 side.
In the case of implementing the present invention, 1 module may be configured to include a plurality of flip-chip mounted devices 22, or 1 elastic wave device for each of the plurality of flip-chip mounted devices 22. The flip-chip mounted device 22 may include not only an amplifier but also other active circuits (elements) or passive circuits (elements) such as a switch circuit.
In addition, various modifications and additions can be made without departing from the scope of the invention.
That is, the above description is only an embodiment of the present invention, and the scope of the claims of the present invention is not limited thereto, and the equivalent variations described in the claims and the description of the present invention are also covered by the scope of the claims of the present invention.