Radar module incorporated with a pattern-shaping device
11169250 · 2021-11-09
Assignee
Inventors
Cpc classification
G01S7/03
PHYSICS
H01Q1/2283
ELECTRICITY
H01Q1/3233
ELECTRICITY
H01L2224/12105
ELECTRICITY
G01S7/028
PHYSICS
H01L23/28
ELECTRICITY
H01L2224/04105
ELECTRICITY
H01L2223/6677
ELECTRICITY
H01Q17/001
ELECTRICITY
H01Q1/245
ELECTRICITY
G01S13/02
PHYSICS
G01S7/027
PHYSICS
International classification
G01S13/02
PHYSICS
H01Q1/52
ELECTRICITY
H01Q1/22
ELECTRICITY
H01Q17/00
ELECTRICITY
H01L23/28
ELECTRICITY
G01S7/03
PHYSICS
Abstract
A radar module includes a printed circuit board (PCB) and a semiconductor package mounted on the PCB. The semiconductor package comprises an integrated circuit die and a substrate for electrically connecting the integrated circuit die to the PCB. The substrate comprises an antenna layer integrated into the semiconductor package and electrically connected to the integrated circuit die for at least one of transmitting and receiving radar signals. A discrete pattern-shaping device is mounted on the PCB and is configured to shape a radiation pattern of the radar signals.
Claims
1. A radar module, comprising: a printed circuit board (PCB) having a first surface and a second surface opposite to the first surface; a semiconductor package mounted on the first surface of the PCB, wherein the semiconductor package comprises an integrated circuit die and a substrate for electrically connecting the integrated circuit die to the PCB, wherein the substrate comprises an antenna layer integrated into the semiconductor package and electrically connected to the integrated circuit die for at least one of transmitting and receiving radar signals; and a pattern-shaping device mounted on the first surface of the PCB configured to shape a radiation pattern of said radar signals, wherein the pattern-shaping device comprises a first protrusion and a second protrusion, wherein at least a portion of the integrated circuit die is between the first and second protrusions or below an area between the first and second protrusions.
2. The radar module according to claim 1, wherein the semiconductor package further comprises a molding compound encapsulating the integrated circuit die.
3. The radar module according to claim 2, wherein the pattern-shaping device is a discrete device directly mounted on the first surface of the PCB and a top surface of the molding compound of the semiconductor package.
4. The radar module according to claim 1, wherein the pattern-shaping device is a monolithic piece that is made of a homogeneous material.
5. The radar module according to claim 1, wherein the pattern-shaping device is made of metal, plastic or mmW absorber material.
6. The radar module according to claim 1, wherein the substrate further comprises a ground reflector layer under the antenna layer.
7. The radar module according to claim 6, wherein the ground reflector layer is a metal layer.
8. The radar module according to claim 1, wherein the pattern-shaping device comprises four sidewalls and an intermediate isolation wall, which together define two channels above the semiconductor package, wherein the two channels are aligned with two antenna patterns of the antenna layer, respectively, wherein the first and second protrusions are two of the four sidewalls.
9. The radar module according to claim 8, wherein the four sidewalls comprise an oblique sidewall.
10. The radar module according to claim 9, wherein the oblique sidewall provides an inner slope directly facing the semiconductor package, wherein the inner slope intersects with the first surface of the PCB at an obtuse angle θ ranging between 110 degrees and 160 degrees.
11. A radar module, comprising: a printed circuit board (PCB) having a first surface and a second surface opposite to the first surface; a semiconductor package mounted on the first surface of the PCB, wherein the semiconductor package comprises an integrated circuit die and a substrate for electrically connecting the integrated circuit die to the PCB, wherein the substrate comprises an antenna layer integrated into the semiconductor package and electrically connected to the integrated circuit die for at least one of transmitting and receiving radar signals; a radar main body housing the PCB and the semiconductor package, the radar main body comprising a retainer; and a pattern-shaping device mounted on the retainer configured to shape a radiation pattern of said radar signals, wherein the pattern-shaping device comprises a first protrusion and a second protrusion, wherein at least a portion of the integrated circuit die is between the first and second protrusions or below an area between the first and second protrusions.
12. The radar module according to claim 11, wherein the pattern-shaping device is a monolithic piece that is made of a homogeneous material.
13. The radar module according to claim 11, wherein the pattern-shaping device is made of metal, plastic or mmW absorber material.
14. The radar module according to claim 11, wherein the first protrusion has a sectional profile of equilateral shape, isosceles triangle shape, right-angled triangle shape or trapezoid shape.
15. The radar module according to claim 1, wherein the pattern-shaping device comprises a third protrusion between the first and second protrusions, the third protrusion being an intermediate isolation wall.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:
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DETAILED DESCRIPTION
(8) In the following detailed description of the invention, reference is made to the accompanying drawings which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention.
(9) The terms “die”, “chip”, “semiconductor chip”, and “semiconductor die” are used interchangeable throughout the specification to mean integrated circuit chip or die. The term “horizontal” as used herein may be defined as a direction parallel to a plane or surface (e.g., surface of a substrate or a stage), regardless of its orientation. The term “vertical,” as used herein, may refer to a direction orthogonal to the horizontal direction as just described. Terms, such as “on,” “above,” “below,” “bottom,” “top,” “side” (as in “sidewall”), “higher,” “lower,” “upper,” “over,” and “under,” may be referenced with respect to the horizontal plane.
(10) The present disclosure pertains to a radar module incorporated with a discrete pattern-shaping device, which is capable of providing benefits including, but not limited to, narrower beam width and higher gain. By incorporating various pattern-shaping structures, the customer's gain pattern specification can be met without the need of redesigning the antenna assembly of the Antenna-in-Package (AiP).
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(12) As shown in
(13) According to one embodiment, the semiconductor package 1 may be an Antenna-in-Package (AiP), but is not limited thereto. As can be seen in
(14) According to one embodiment of the invention, the substrate 10 may comprise an antenna layer 110, a ground reflector layer 120 under the antenna layer 110, and an insulating layer 130 between the antenna layer 110 and the ground reflector layer 120. The substrate 10 may further comprise a plurality of ball pads 122 for attaching the solder balls 50. According to one embodiment of the invention, the ball pads 122 and the ground reflector layer 120 are coplanar and are formed in the same metal layer of the substrate 10.
(15) According to one embodiment of the invention, the antenna layer 110 and the ground reflector layer 120 are formed in two different metal layers (e.g., copper layers) of the substrate 10. The two metal layers are in different horizontal planes. For example, the substrate 10 may comprise an upper surface that is closer to the integrated circuit die 20 and a lower surface opposite to the upper surface. The antenna layer 110 may be formed at the upper surface and is therefore closer to the integrated circuit die 20. The antenna layer 110 may be electrically connected to the integrated circuit die 20 through an interconnect or a trace 112. The ground reflector layer 120, which may be electrically connected to a ground plane of the PCB 100, may be formed at the lower surface and is therefore closer to the PCB 100. Although not shown in the figures, it is to be understood that the metal layers in the substrate 10 may be interconnected through conductive vias if necessary.
(16) According to one embodiment of the invention, the antenna layer 110 may comprise two rectangular-shaped antenna patterns 110a and 110b. The antenna pattern 110a is spaced apart from the antenna pattern 110b. According to one embodiment of the invention, for example, both of the antenna pattern 110a and the antenna pattern 110b may have dimension of about (80 .sub.g/2)×(λ.sub.g/2), wherein λ.sub.g is the guided wavelength of the electromagnetic radiation transmitted via the antenna layer 110, for example, a W-band radar, operating at 77 GHz, would have a λ.sub.g=1.1˜1.3 mm, wherein the substrate dielectric constant (ε.sub.r) is about 3.6. Only for illustration purposes, the antenna pattern (transmit antenna) 110a may be used to transmit a send radar signal (T.sub.x) and the antenna pattern (receive antenna) 110b may be used to receive a reflected radar signal (R.sub.x).
(17) It is to be understood that the antenna layer 110 can be realized by any type of antenna structure. In the illustrated embodiment of this disclosure, a patch antenna is selected due to its high gain and broadside radiation characteristics. According to other embodiments of the invention, the antenna layer 110 may be a phased-array antenna, a dipole antenna, a slot antenna, etc. According to one embodiment of the invention, the ground reflector layer 120 may be a solid metal layer such as a solid copper layer, which completely overlaps with the antenna layer 110 when viewed from the above.
(18) According to one embodiment of the invention, the integrated circuit die 20 may be an integrated circuit (IC) silicon die or a semiconductor chip that comprises relative functional circuits for transmitting and/or receiving radar or RF signals. According to one embodiment of the invention, the integrated circuit die 20 may have an active surface 20a and a passive surface 20b that is opposite to the active surface 20a. A plurality of input/output (I/O) pads 210 may be disposed on the active surface 10a. According to one embodiment of the invention, the active surface 10a of the integrated circuit die 20 may be integrally joined with the upper surface of the substrate 10. The antenna layer 110 may be electrically connected to respective I/O pads 210 on the active surface 20a of the integrated circuit die 20 through the interconnect or the trace 112.
(19) According to one embodiment of the invention, the molding compound 30 may comprise organic resin typically used in the encapsulation of integrated circuit devices and selected for low moisture permeability and low thermal coefficient of expansion to avoid exposure of the encapsulated chip to moisture or mechanical stress, respectively. For example, according to one embodiment of the invention, the molding compound 30 may comprise epoxy materials. The molding compound 30 may further comprise fillers, such as amorphous silicon oxide (silica glass) and/or crystalline silicon oxide (quartz) fillers. Suitable additives may be added to enhance the thermal conductivity of the molding compound 30. According to one embodiment of the invention, the molding compound 30 may have a dielectric constant k ranging between 3.3 and 3.4, for example. According to one embodiment of the invention, the molding compound 30 may have a thickness of about 1.1˜1.3 mm, for example, 1.2 mm, but is not limited thereto.
(20) According to one embodiment of the invention, for example, the semiconductor package 1 may be a fan-out wafer level package (FOWLP) and the substrate 10 may be a re-distribution layer (RDL) substrate. As known in the art, wafer level package (WLP) involves packaging the die while it is still on the wafer. Generally, WLP is a substrate-less package. Instead of a substrate, WLP utilizes a thin-film of routing layers, or redistribution layers (RDLs), which provide electrical connections in the package. WLP makes use of solder balls 50 on the bottom of the package, which connects the RDLs to a board or a printed circuit board (PCB).
(21) According to one embodiment of the invention, the radar module M further comprises a discrete pattern-shaping device 2 is externally and directly mounted on the first surface 100a of the PCB 100 and on a top surface 30a of the molding compound 30 of the semiconductor package 1 by using an adhesive layer 210 or the like. According to one embodiment of the invention, the pattern-shaping device 2 is preferably a monolithic piece that is made of a homogeneous material. For example, the pattern-shaping device 2 may be made of metal, plastic, mmW absorber materials, or any suitable materials capable of implementing radiation pattern shaping of radar signals. According to one embodiment of the invention, the pattern-shaping device 2 may be made of copper, but is not limited thereto.
(22) According to one embodiment of the invention, the pattern-shaping device 2 may comprise four sidewalls 201˜204 and an intermediate isolation wall 205, which together define two compartments or channels C.sub.a and C.sub.b above the semiconductor package 1. According to one embodiment of the invention, the channel C.sub.a is aligned with the antenna pattern (transmit antenna) 110a and the channel C.sub.b is aligned with the antenna pattern (receive antenna) 110b. In some embodiments, the intermediate isolation wall 205 is optional and may be omitted.
(23) According to one embodiment of the invention, the two opposite sidewalls 201 and 202 are vertical sidewalls, which protrude and extend vertically from the first surface 100a of the PCB 100. The two opposite sidewalls 201 and 202 are in parallel with the reference XZ plane. According to one embodiment of the invention, the two opposite sidewalls 201 and 202 are fixed to the first surface 100a of the PCB 100 and have a height h.sub.1 approximately ranging between 4 and 12 mm, but is not limited thereto.
(24) The intermediate isolation wall 205 is in parallel with the sidewalls 201 and 202 and is interposed between the sidewalls 201 and 202. The intermediate isolation wall 205 partially overlaps with the underlying semiconductor package 1. According to one embodiment of the invention, the intermediate isolation wall 205 is a vertical wall, which protrudes and extends vertically from the top surface 30a of the molding compound 30 of the semiconductor package 1. According to one embodiment of the invention, the intermediate isolation wall 205 has a height h.sub.2 approximately ranging between 3 and 12 mm, which is not limited thereto, from the top surface 30a of the molding compound 30.
(25) According to one embodiment of the invention, the sidewall 203 is a vertical sidewall, which preferably protrudes and extends vertically from the top surface 30a of the molding compound 30 of the semiconductor package 1. The sidewall 203 is in parallel with the reference YZ plane and is integrally connected to the sidewalls 201 and 202 and the intermediate isolation wall 205 at a right angle.
(26) According to one embodiment of the invention, the sidewall 204, which is opposite to the sidewall 203, is an oblique sidewall. The oblique sidewall may be used to expand the field distribution of the antenna, making the field distribution more uniform. The sidewall 204 provides an inner slope 204a directly facing the semiconductor package 1. The inner slope 204a intersects with the first surface 100a of the PCB 100 at an obtuse angle θ. According to one embodiment of the invention, the obtuse angle θ may range between 110 degrees and 160 degrees, depending upon the design requirements. The sidewall 204 is integrally connected to the sidewalls 201 and 202 and the intermediate isolation wall 205.
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(36) As shown in
(37) Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.