JP2021035001A - Antenna integrated type module - Google Patents

Abstract

To provide an antenna integrated type radio module having an excellent characteristic by reducing a transmission loss in a rail track as much as possible.SOLUTION: An antenna integrated type module A comprises: an interposer substrate 4; and a package 2 of an integrated radio circuit. A package 2 is mounted onto the substrate 4, and a transmission antenna 6 and a reception antenna 7 are structured. Each of the antennas 6 and 7 comprises a signal wire 8 structured so as to be extended to an inner side of a surface normal line direction of the substrate from a feeding point. A terminal 2a of the package 2 is structured so that in configuration regions R1 and R1a of a copper foil surface 4a containing a contact region of the substrate contacted via a solder ball 5 to the interposer substrate 4 and a configuration region R2 of a signal line 8 extended from the feeding point of the antennas 6 and 7, one part of at least one region is contained in the other region in a flat surface inner direction of the interposer substrate 4. Thus, a rail track for connecting the terminal 2a with the antennas 6 and 7 can be reduced.SELECTED DRAWING: Figure 1

Description

The present invention relates to an antenna integrated module.

Conventionally, wireless devices used for high-speed wireless data communication terminals and millimeter-wave radar systems have been required to be low in height and thin, and in recent years, antennas adopted have been made low in height by using a substrate. It meets the demand for thinner products. However, if a long transmission line is provided between the wireless integrated circuit and the antenna configured on the board, the loss in the high frequency band is large, and the communication signal is attenuated between the wireless integrated circuit and the antenna. , The communication characteristics are significantly deteriorated. Therefore, it is desired to configure the antenna while suppressing the loss of the transmission line as much as possible.

Japanese Unexamined Patent Publication No. 2018-20716

The present disclosure is to provide an antenna-integrated module capable of improving the characteristics by minimizing the transmission loss of a line.

The invention according to claim 1 includes a substrate (4) and a package (2) for a wireless integrated circuit. The package (2) is mounted on the substrate (4), and the antennas (6, 7) are configured. The antenna includes a signal line (8) configured to extend inward in the plane normal direction of the substrate from the feeding point. The constituent regions (R1, R1a) of the conductive surface (4a) including the contact region of the substrate in which the terminals of the package are in contact with the substrate through the metal body (5), and the constituent regions of the signal line extending from the feeding point of the antenna. (R2) is configured so that at least a part of one region is included in the other region in the in-plane direction of the substrate. According to the invention of claim 1, the line connecting the terminal and the antenna can be shortened, the transmission loss of the line can be reduced as much as possible, and the characteristics can be improved.

Longitudinal side view of the antenna-integrated wireless module according to the first embodiment Perspective view schematically showing the overall structure Side view of wireless module with integrated antenna Perspective view schematically showing the structure of the pseudo waveguide slot antenna for multiple channels Perspective view schematically showing the structure of the coaxial waveguide converter Perspective view schematically showing the structure of the pseudo waveguide slot antenna for a plurality of channels according to the second embodiment. Perspective view schematically showing the structure of the coaxial waveguide converter and the recombination layer. Perspective view schematically showing the connection structure of the microstrip antennas for a plurality of channels according to the third embodiment. Perspective view schematically showing the structure of the coaxial waveguide converter and the recombination layer.

Hereinafter, some embodiments will be described with reference to the drawings. In each of the embodiments described below, the same reference numerals may be given to the configurations that perform the same operation, and the description thereof may be omitted.

(First Embodiment)
An antenna-integrated module A is configured on the printed circuit board 1 shown in FIG. The antenna integrated module A is mainly composed of a package 2 of a wireless integrated circuit by MMIC (Monolithic Microwave Integrated Circuit) and an interposer board 4 on which the package 2 is mounted.

The package 2 is mounted on the interposer board 4 and fixed on the upper surface of the interposer board 4. Package 2 is based on WLCSP (Wafer level Chip Size Package).

The wireless integrated circuit configured inside the package 2 generates a signal S in the millimeter wave band modulated by a method such as FMCW (Frequency Modulated Continuous Wave), and transmits transmitters for a plurality of channels to transmit each. It is a radio integrated circuit for radar provided with receivers for a plurality of channels for receiving signals S in the millimeter wave band reflected on the target, and is used for automobile radar applications and the like.

On the other hand, a power supply circuit and a control circuit for a wireless integrated circuit (not shown) are mounted on the printed circuit board 1, and the power supply circuit and the control circuit are connected to the interposer board 4 through a connection solder 3 for power supply and control signals. Has been done. An interposer board 4 is mounted on the upper surface of the package 2 of the wireless integrated circuit, and power and control signals are supplied to the package 2 through the interposer board 4.

The interposer substrate 4 is a build-up type laminated structure substrate configured by repeating lamination, drilling, wiring formation, etc. for each layer. As shown in FIG. 1, the interposer substrate 4 is configured by providing a plurality of layers L1 to L6 with copper foil surfaces 4a serving as conductive surfaces, and sandwiching a dielectric layer between these layers L1 to L6. Hereinafter, the layer L1 will be defined as the surface layer L1 and the layer L6 will be defined as the back layer L6, but the number of layers of the interposer substrate 4 may be any number. The copper foil surface 4a may be made of a conductor of another metal.

The intermediate layer (for example, L4) of the interposer substrate 4 is configured as a large area, low impedance ground G. The interposer substrate 4 is formed by laminating a laminated structure of an upper layer and a lower layer with an intermediate layer as a boundary. Each layer L1 to L6 is formed with a pattern formed by copper foil surfaces 4a, and the patterns are electrically connected by stacked vias V1 ... V5 to form a circuit. Since the interposer board 4 is configured as a build-up type, the hole diameters of the stacked vias V1 ... V5 and the wiring length of the inner layer pattern can be freely changed.

A plurality of bare chip terminals 2a are exposed on the upper surface of the package 2. Of these plurality of terminals 2a, the terminals 2a at both ends in the X direction in FIG. 1 are assigned to the transmission terminal Txout and the reception terminal Rxin, respectively, and the terminals 2a arranged in the middle are the ground terminal GND and the power supply. It is assigned to the terminal PS and various control terminals CS.

When the package 2 is mounted on the interposer substrate 4, the upper surface of the bare chip is inverted and the upper surface of the bare chip is face-down mounted on the surface of the layer L1 of the interposer substrate 4. Face-down mounting is a mounting method in which a solder ball 5 such as tin (Sn) -silver (Ag) is used as a metal body to join the package 2 and the interposer substrate 4. The bumps made of gold (Au) may be bonded by thermocompression bonding, or may be joined by another metal body such as copper (Cu).

The transmission terminal Txout is a terminal 2a to which a signal S is output from the transmitter of the wireless integrated circuit inside the package 2. The receiving terminal Rxin is a terminal 2a for inputting a signal S to the receiver of the wireless integrated circuit inside the package 2.

A plurality of transmission terminals Txout are arranged side by side in the normal direction of the publication surface of FIG. 1, whereby signals S of transmitters for a plurality of channels can be transmitted and output. Although not shown in FIG. 1, the transmission terminal Txout is arranged so as to be sandwiched between the two ground terminals GND along the normal direction of the mounting surface of FIG. A plurality of receiving terminals Rxin are also arranged side by side in the normal direction of the publication surface of FIG. 1, so that signals S can be received and input to receivers for a plurality of receiving channels. Similarly, the receiving terminal Rxin is arranged so as to be sandwiched between the two ground terminals GND along the normal direction of the mounting surface of FIG. These terminals 2a are in contact with the copper foil surface La of the layer L1 exposed on the lower surface of the interposer substrate 4 through the solder balls 5 which are metal bodies.

By the way, as shown in FIGS. 1 and 3, a transmitting antenna 6 and a receiving antenna 7 are configured on the interposer board 4. The transmitting antenna 6 and the receiving antenna 7 are configured by using the multilayer structure of the interposer substrate 4. In this embodiment, a mode in which the transmitting antenna 6 and the receiving antenna 7 are composed of a three-dimensional antenna by a pseudo waveguide slot antenna 6a will be described. Since the structures of the transmitting antenna 6 and the receiving antenna 7 have the same structure, the structure of the transmitting antenna 6 will be described and the description of the structure of the receiving antenna 7 will be omitted.

The plurality of transmission terminals Txout of the package 2 output signals S for a plurality of channels to the plurality of transmission antennas 6 through their respective feeding points. As shown in FIG. 4, the transmitting antenna 6 is arranged side by side for a plurality of channels on the interposer board 4.

The transmitting antenna 6 includes a signal line 8 serving as a waveguide conversion post composed of a stacked structure Va of stacked vias V1 to V4, and a pseudo waveguide slot having a slot SL in the waveguide serving as an electromagnetic wave transmission path. It is composed of an antenna 6a. The stacked vias V1 ... V4 are vertically connected in the Z direction and serve as feeding points for the transmitting antenna 6.

A land La and a waveguide surface Lb are formed on the layer L1 of the interposer substrate 4. The land La is arranged so as to connect between the solder ball 5 and the signal line 8, is located on the surface layer L1 and is configured to be separated in an island shape. The waveguide surface Lb is configured to have a low impedance by being widely formed in a plane shape away from the land La. Further, a waveguide surface Lc is formed on the layer L6 of the interposer substrate 4, and a slot SL is formed on the waveguide surface Lc.

The waveguides of the pseudo waveguide slot antennas 6a for a plurality of channels are each configured in the inner layer of the interposer substrate 4, and are post-wall guides configured by using the stacked via laminated structure Va by the stacked vias V1a to V5a. The waveguide 9 separates the waveguides from each other.

In the post-wall waveguide 9, the stacked Via laminated structure Va is arranged at a predetermined interval of less than λ / 4 of the wavelength of the signal S, and the Stacked Via laminated structure Va connects the waveguide surfaces Lb and Lc. The inner layer of the interposer substrate 4 is regarded as a waveguide structure to form a waveguide. By configuring the pseudo-waveguide slot antenna 6a on the interposer substrate 4, it is possible to propagate signals in the same transmission mode as the metal rectangular waveguide, which is similar to that of the metal rectangular waveguide slot antenna. Using the principle, electromagnetic waves can be efficiently radiated in the direction opposite to the mounting surface of the package 2. The stacked vias V1a to V5a between the layers constituting the post-wall waveguide 9 are shared between the waveguides of a plurality of adjacent channels. The configuration of this embodiment can be miniaturized as compared with the configuration in which the post-wall waveguide 9 is separately configured (see the embodiment below).

As shown in FIG. 1, the signal line 8 is configured to extend inward in the plane normal direction of each layer L1 to L6 of the interposer substrate 4. In the interposer substrate 4, the signal line 8 is configured by stacking a plurality of stacked vias V1 to V4 in the Z direction. The signal line 8 constitutes a core line of a coaxial transmission line. As shown in FIG. 1, the stacked vias V1 to V4 are formed by connecting some layers L1-L5 between all the layers from the surface layer L1 to the back layer L6 of the interposer substrate 4, and are formed in a plane. Is configured in the same region R2.

As shown in FIG. 1, the component region R1 of the copper foil surface 4a including the contact region where the terminal 2a of the package 2 comes into contact with the interposer substrate 4 through the solder ball 5 through the solder ball 5 extends from the feeding point of the transmitting antenna 6. The constituent region R2 of the signal line 8 to be formed is included. Further, as shown in FIGS. 4 and 5, the constituent region R1a that contacts the interposer substrate 4 through the solder balls 5 may be configured in the same region as the constituent region R2 of the signal line 8. As a result, the length up to the signal line 8 can be shortened as much as possible. The line loss can be reduced as much as possible, the characteristics can be improved, and the size can be reduced.

In the wireless integrated circuit inside the package 2, a coaxial transmission line such as a coplanar line is connected to the terminal 2a up to the transmission terminal Txout (and the ground terminal GND separated on both sides in the drawing). As shown in FIG. 4, it is preferable that the pitch between the signal lines 8 connected to the transmitting antennas 6 for the plurality of channels is the same as the pitch between the plurality of terminals 2a. Then, a plurality of transmitting antennas 6 can be arranged side by side efficiently.

As shown in FIG. 5, the interposer substrate 4 includes a structure of a coaxial waveguide converter 10 that converts a coaxial transmission line and a transmission line of the waveguide of the pseudo waveguide slot antenna 6a. The antenna-integrated module A has a structure suitable for realizing the structure of the coaxial waveguide converter 10 because the signal line 8 by the stacked vias V1 ... V4 that draws the signal S inside the interposer board 4 can be easily configured. As a result, the transmission loss can be reduced.

<Summary>
When an impedance matching circuit of a transmission circuit of a wireless integrated circuit and a transmission antenna 6 is configured in a millimeter wave band (for example, 79 GHz band), transmission loss is likely to occur even if the wiring length of the matching circuit is 1 cm. According to this embodiment, the terminals 2a are extended from the feeding point of the transmitting antenna 6 to the constituent regions R1 and R1a of the copper foil surface 4a including the contact region of the interposer substrate 4 in which the terminal 2a is in contact with the interposer substrate 4 through the solder balls 5. The constituent region R2 of the signal line 8 is configured to be included in the in-plane direction of the interposer substrate 4. As a result, the transmission loss can be reduced and the characteristics can be improved.

According to the present embodiment, the signal S is energized to the land La of the interposer substrate 4 via the terminal 2a, and then extends in the vertical direction (Z direction) in the substrate, not in the substrate surface direction (X direction). It is pulled out to Stacked Via V1 to V4. Since the stacked vias V1 ... V5 can be connected from directly below the terminal 2a of the package 2 and the feeding point of the transmitting antenna 6, the degree of freedom in designing the feeding circuit reaching the feeding point of the transmitting antenna 6 can be improved. Moreover, the discontinuity point of impedance can be reduced, and the transmission loss can be lowered. According to the present embodiment, it is possible to configure the package 2 and the transmitting antenna 6 with almost no transmission line, and by shortening the length of the connection structure, the transmission loss can be reduced. Further, the entire antenna-integrated module A can be miniaturized and can be configured at low cost.

According to this embodiment, the post wall waveguides 9 are arranged in parallel for multi-channel. When such a structure of the post-wall waveguide 9 is adopted, the isolation characteristics between the channels can be improved as compared with, for example, a microstrip line transmitting on the substrate surface.

Since the connection structure of the receiving antenna 7 is the same as the connection structure of the transmitting antenna 6, the description thereof will be omitted, but the same effect can be obtained by adopting the same structure as the transmitting antenna 6 for the receiving antenna 7. Needless to say.

(Second Embodiment)
For example, depending on the design dimensions of the waveguide size of the pseudo waveguide slot antenna 6a, the pitch of the terminals 2a, and the design dimensions of the spacing between channels, it may not be possible to directly connect the terminal 2a to the signal line 8. Such a case can be dealt with by using the rewiring layer 12 configured inside the package 2 of the WLCSP.

The transmitting antenna 206 shown in FIG. 6 shows an antenna structure that replaces the transmitting antenna 6. FIG. 7 shows a partially enlarged view including the wiring of the ground G.
As shown in FIG. 6, the transmitting antenna 206 includes a pseudo waveguide slot antenna 206a for each channel, similarly to the transmitting antenna 6. The pseudo waveguide slot antenna 206a separately constitutes a post-wall waveguide 9 for each channel, and the waveguide is separated for each channel. As a result, the interaction between each channel can be reduced. Further, regardless of the pitch of the terminal 2a of the package 2, the spacing between the waveguides by the post-wall waveguide 9 and the spacing between adjacent channels of the post-wall waveguide 9 can be easily designed, and the dimensions of the transmitting antenna 206 can be adjusted. Easy to design. Therefore, the degree of freedom in design of the transmitting antenna 206 and its matching circuit can be improved.

On the other hand, the package 2 is composed of a fan-in type or fan-out type wafer level package. The wireless integrated circuit configured in the package 2 includes an integrated circuit transmission line 11 that transmits a signal S to the transmitting antenna 206. As shown in FIG. 7, the transmission line 11 in the integrated circuit includes a signal transmission line 13 for transmitting the signal S. The signal transmission line 13 is made of aluminum (Al) wiring or the like, and constitutes a transmission line 11 in an integrated circuit together with ground wiring that defines the potential of ground G arranged on both sides. The rewiring layer 12 is configured to extend from the transmission line 11 in the integrated circuit to the terminal 2a. The rewiring layer 12 is a wiring layer that connects the transmission line 11 in the integrated circuit and the terminal 2a to convert the transmission line.

In the present embodiment, the pitch between the terminals 2a of the package 2 that transmits the signal S and the pitch of the transmission line 11 in the integrated circuit that transmits the signal S are different from each other. However, since the rewiring layer 12 is provided, the transmission antenna 206 and the transmission line 11 in the integrated circuit can be easily connected regardless of the pitch spacing of the terminals 2a for the plurality of channels. Moreover, the spacing between the waveguides by the post-wall waveguide 9 and the spacing between adjacent channels of the post-wall waveguide 9 can be easily changed, and the dimensions of the transmitting antenna 206 can be easily designed.

Since the loss depends on the electrical characteristics of the interposer substrate 4, low-loss substrate materials have also been studied, but there may be physical restrictions on the arrangement of the transmitting antennas 6 for a plurality of channels. If each component is miniaturized, isolation problems between adjacent channels are likely to occur. According to this embodiment, it becomes easy to design the isolation characteristics between channels to the required characteristics.

(Third Embodiment)
As shown in FIGS. 8 and 9, the transmitting antenna 306 is composed of a flat antenna using a copper foil surface 4a of the back layer L6 which is an exposed surface of the interposer substrate 4, for example, a microstrip antenna.

The terminal 2a of the package 2 is in contact with the land La of the interposer substrate 4 via the solder ball 5. Further, the land La is connected to the transmission line 14 in the inner layer of the interposer substrate 4 by the stacked vias V1 ... V2. The transmission line 14 is routed to just below the feeding point of the transmitting antenna 306, and further penetrates to the back layer L6 by stacked vias V3 ... V5 and is connected to the feeding point of the transmitting antenna 306.

Therefore, the signal S is energized to the land La of the interposer substrate 4 via the terminal 2a of the package 2 and the solder ball 5, and then transmitted to the transmission line 14 in the inner layer of the interposer substrate 4 by the stacked vias V1 to V2 between the layers. Will be done. Further, the signal S is fed to the feeding point of the transmitting antenna 306 provided on the surface opposite to the mounting surface of the package 2 through the transmission line 14 in the inner layer and the stacked vias V3 ... V5.

In this case, since the connection can be made in the shortest distance from the terminal 2a of the package 2 to just below the feeding point of the transmitting antenna 306, the connecting distance can be shortened, and the feeding loss can be reduced as in the above-described embodiment.
The antenna-integrated module A of the present embodiment supplies power to the transmitting antenna 306 by using the transmission line 14 inside the interposer board 4. In this case as well, the power supply loss can be reduced.

(Other embodiments)
The present disclosure is not limited to the above-described embodiment, and can be implemented in various modifications, and can be applied to various embodiments without departing from the gist thereof. For example, the following modifications or extensions are possible.
The form in which the resin substrate is used for the interposer substrate 4 has been described, but the present invention is not limited to this, and a ceramic substrate may be used.

The constituent area R1 or R1a and the constituent area R2 may be configured so that at least a part of one of the regions in the plane direction of the interposer substrate 4 is included in the other region. In this case as well, the first embodiment is performed. Similar to the form, the transmission loss of the line can be reduced as much as possible and the characteristics can be improved.

Wireless integrated circuits have been applied to, but are not limited to, semiconductor integrated circuits (MMICs) in millimeter-wave radar systems for vehicles. The wireless integrated circuit of Package 2 may be not only a monolithic IC but also a HIC (Hybrid Integrated Circuit), and can be applied as long as it is a wireless integrated circuit used in a wireless frequency band.

The present disclosure also includes an embodiment in which the configurations and functions of the plurality of embodiments described above are combined. An embodiment in which a part of the above-described embodiment is omitted as long as the problem can be solved can also be regarded as an embodiment. In addition, any conceivable embodiment can be regarded as an embodiment without departing from the essence of the invention specified by the wording described in the claims.

Although the present disclosure has been described in accordance with the above-described embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure also includes various modifications and modifications within a uniform range. In addition, various combinations and forms, as well as other combinations and forms, including one element, more, or less, are also within the scope and ideology of the present disclosure.

In the drawing, A is an antenna integrated module, 2 is a wireless integrated circuit package, 4 is an interposer substrate (board), 4a is a copper foil surface (conductive surface), 5 is a solder ball (metal body), and L1 to L6 are layers. , V1 ... V5 indicates stacked via.

Claims (9)

Wireless integrated circuit package (2) with exposed terminals and
A substrate (4) on which the package is mounted and an antenna (6, 7) is configured is provided.
The antenna includes a signal line (8) configured to extend inward in the plane normal direction of the substrate from the feeding point.
The signal extending from the constituent regions (R1, R1a) of the conductive surface (4a) including the contact region of the substrate in which the terminals of the package are in contact with the substrate through the metal body (5) and the feeding point of the antenna. The wire constituent region (R2) is an antenna-integrated module configured so that at least a part of one region is included in the other region in the in-plane direction of the substrate. The substrate is composed of a laminated structure substrate, and the layers are configured to be connectable by stacked vias (V1 to V4).
The antenna-integrated module according to claim 1, wherein the signal line is formed by stacking a plurality of the stacked vias. The package is a fan-in or fan-out wafer level package.
A transmission line in an integrated circuit that is configured in the wireless integrated circuit and transmits or receives a signal to the antenna.
A rewiring layer configured in the wireless integrated circuit, connecting the transmission line in the integrated circuit and the terminal to convert the transmission line,
The antenna-integrated module according to claim 1 or 2. The antenna-integrated module according to claim 3, wherein the pitch between the terminals of the package that transmits the signal and the pitch of the transmission line in the integrated circuit that transmits the signal are different from each other. The antennas (6, 7) are arranged side by side for a plurality of channels on the substrate.
The package of the wireless integrated circuit includes a plurality of terminals for transmitting or receiving signals for the plurality of channels through the feeding points of the respective antennas.
The invention according to any one of claims 1 to 4, wherein the pitch between the signal lines (8) for the plurality of channels is the same as the pitch between the plurality of terminals (2a). Antenna integrated module. The antennas (6, 7) are composed of a pseudo waveguide slot antenna (6a) in which a slot (S) is formed in a waveguide serving as an electromagnetic wave transmission path.
The signal line constitutes a core wire of a coaxial transmission line extending in the plane normal direction of the substrate.
The antenna-integrated module according to any one of claims 1 to 5, wherein the substrate includes a structure of a coaxial waveguide converter (10) that converts the coaxial transmission line and the transmission line of the waveguide. .. The antenna-integrated module according to claim 6, wherein the pseudo waveguide slot antenna is arranged side by side for a plurality of channels on the substrate. The waveguides for the plurality of channels each include a post-wall waveguide (9) configured by using stacked vias (V1a to V5a) between layers with respect to the inner layer of the substrate.
The antenna-integrated module according to claim 5, wherein the stacked vias between the layers constituting the post-wall waveguide are shared between the waveguides of the plurality of adjacent channels. The antenna (306) is composed of a flat antenna (306) configured by using the exposed surface of the substrate.
The antenna-integrated module according to any one of claims 1 to 3, wherein the signal line of the antenna is connected to the planar antenna by penetrating the inner layer of the substrate to the exposed surface.

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