CN117878096A

CN117878096A - Package structure and method for forming the same

Info

Publication number: CN117878096A
Application number: CN202410052810.5A
Authority: CN
Inventors: 房志强
Original assignee: Changdian Technology Management Co ltd
Current assignee: Changdian Technology Management Co ltd
Priority date: 2024-01-12
Filing date: 2024-01-12
Publication date: 2024-04-12

Abstract

A package structure and method of forming the same, the package structure comprising: a first substrate; a first semiconductor chip mounted on the lower surface of the first substrate; the first waveguide transmission structure is positioned in the first substrate and is electrically connected with the first semiconductor chip; a molding layer covering the upper surface of the first substrate; a rectangular waveguide in the plastic layer, the rectangular waveguide being located above the first waveguide transmission structure; the second substrate is mounted on the upper surface of the plastic sealing layer and comprises an upper surface and a lower surface which are opposite; a second waveguide transmission structure located in the second substrate, and the second waveguide transmission structure is located above the rectangular waveguide; and the second semiconductor chip is attached to the upper surface of the second substrate and is electrically connected with the second waveguide transmission structure. The low-loss transmission of millimeter wave radio frequency signals in the packaging structure of the multilayer structure is realized.

Description

Package structure and method for forming the same

Technical Field

The present disclosure relates to semiconductor packaging, and more particularly, to a packaging structure and a method for forming the same.

Background

In order to achieve better performance, keep smaller volume and lower power consumption, existing packaging technologies are evolving from early 2D packaging towards 2.5D stereoscopic packaging, 3D stereoscopic packaging.

As a packaging form in the 3D stereo package, a PoP (Package on Package) stack package generally has an upper substrate and a lower substrate stacked one on top of the other, and corresponding chips are respectively attached to the upper substrate and the lower substrate. The existing upper substrate and the lower substrate are usually electrically connected through Metal bars or sealant through holes (Through Encapsulant Via, TEV), but the frequency of signals is gradually increased, and the signal loss caused by the electrical connection mode is also huge, so that the performance of the packaging structure is affected.

Disclosure of Invention

Some embodiments of the present application provide a package structure, including:

a first substrate including opposite upper and lower surfaces;

a first semiconductor chip mounted on the lower surface of the first substrate;

the first waveguide transmission structure is positioned in the first substrate and is electrically connected with the first semiconductor chip;

a molding layer covering the upper surface of the first substrate;

A rectangular waveguide in the plastic layer, the rectangular waveguide being located above the first waveguide transmission structure;

the second substrate is mounted on the upper surface of the plastic sealing layer and comprises an upper surface and a lower surface which are opposite;

a second waveguide transmission structure located in the second substrate, and the second waveguide transmission structure is located above the rectangular waveguide;

the second semiconductor chip is mounted on the upper surface of the second substrate, the second semiconductor chip is electrically connected with the second waveguide transmission structure, the first semiconductor chip is used for generating a first millimeter wave radio frequency signal, the first millimeter wave radio frequency signal is transmitted to the second semiconductor chip to be received through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure, or the second semiconductor chip is used for generating a second millimeter wave radio frequency signal, and the second millimeter wave radio frequency signal is transmitted to the first semiconductor chip to be received through the second waveguide transmission structure, the rectangular waveguide and the first waveguide transmission structure.

In some embodiments, the first waveguide transmission structure includes a first upper metal layer, a first lower metal layer, and a first cavity structure between the first upper metal layer and the first lower metal layer, the first upper metal layer being located on an upper surface of the first substrate, the first lower metal layer being located on a lower surface of the first substrate, the first upper metal layer having a first slot therein, the first lower metal layer having a first grounded coplanar waveguide therein, the first slot and the first grounded coplanar waveguide being located above and below the first cavity structure, respectively, the first grounded coplanar waveguide in the first waveguide transmission structure being electrically connected with the first semiconductor chip;

The rectangular waveguide comprises an upper port and a lower port which are opposite, and the lower port of the rectangular waveguide surrounds a first slot groove of the first waveguide transmission structure;

the second waveguide transmission structure comprises a second upper metal layer, a second lower metal layer and a second cavity structure positioned between the second upper metal layer and the second lower metal layer, wherein the second upper metal layer is positioned on the upper surface of the second substrate, the second lower metal layer is positioned on the lower surface of the second substrate, a second gap groove is formed in the second lower metal layer and surrounded by an upper port of the rectangular waveguide, a second grounding coplanar waveguide is formed in the second upper metal layer, the second gap groove and the second grounding coplanar waveguide are respectively positioned below and above the second cavity structure, and the second semiconductor chip is electrically connected with the second grounding coplanar waveguide in the second waveguide transmission structure.

In some embodiments, the process of first millimeter wave radio frequency signal transmission includes: the first semiconductor chip generates a first millimeter wave radio frequency signal; the first grounding coplanar waveguide receives a first millimeter wave radio frequency signal generated by the first semiconductor chip, feeds the first millimeter wave radio frequency signal into the first cavity structure, and transmits the fed first millimeter wave radio frequency signal to the first slot groove through the first cavity structure and radiates into the rectangular waveguide through the first slot groove for transmission; the second slot groove receives a first millimeter wave radio frequency signal transmitted and output from the upper port of the rectangular waveguide, and couples the received first millimeter wave radio frequency signal into a second cavity structure to be transmitted to the second grounded coplanar waveguide; the second semiconductor chip receives the first millimeter wave radio frequency signal transmitted in the second grounded coplanar waveguide.

In some embodiments, the second millimeter wave radio frequency signal transmission process includes: the second semiconductor chip generates a second millimeter wave radio frequency signal; the second grounding coplanar waveguide receives a second millimeter wave radio frequency signal generated by the second semiconductor chip, feeds the second millimeter wave radio frequency signal into the second cavity structure, and transmits the fed second millimeter wave radio frequency signal to the second slot groove through the second cavity structure and radiates into the rectangular waveguide through the second slot groove for transmission; the first slot groove receives a second millimeter wave radio frequency signal transmitted from the lower port of the rectangular waveguide, and couples the received second millimeter wave radio frequency signal into a first cavity structure to be transmitted to the first grounded coplanar waveguide; the first semiconductor chip receives a first millimeter wave radio frequency signal transmitted in the first grounded coplanar waveguide.

In some embodiments, the first substrate has a plurality of first metal via structures arranged in an array, the upper and lower ends of the first metal via structures are respectively electrically connected with the first upper metal layer and the first lower metal layer, and a region surrounded by the plurality of first metal via structures is a first cavity structure; the second substrate is internally provided with a plurality of second metal through hole structures which are arranged in an array manner, the upper end and the lower end of each second metal through hole structure are respectively and electrically connected with the second upper metal layer and the second lower metal layer, and a plurality of areas surrounded by the second metal through hole structures are second cavity structures.

In some embodiments, the first slot and the second slot are configured identically, and the first slot and the second slot are "i" shaped, "one" shaped, "U" shaped, or "V" shaped.

In some embodiments, the first grounded coplanar waveguide and the second grounded coplanar waveguide are identical in structure, and each of the first grounded coplanar waveguide and the second grounded coplanar waveguide includes a feeder line and a third slot groove located around the feeder line.

In some embodiments, the feed line is "medium" or "racket" shaped.

In some embodiments, the upper port of the rectangular waveguide is the same size as the lower port of the second cavity structure.

In some embodiments, the rectangular waveguide includes rectangular grooves in and through the plastic layer and metal layers on the peripheral sidewall surfaces of the rectangular grooves.

In some embodiments, the first millimeter wave radio frequency signal and the second millimeter wave radio frequency signal have a frequency of 90GHz-110GHz and a wavelength of 2.7mm-3.3mm.

In some embodiments, when the first slot is in an "i" shape and the feeder is in a "medium" shape, the insertion loss is less than or equal to-2 db and the return loss is less than or equal to-15 db when the first millimeter wave radio frequency signal or the second millimeter wave radio frequency signal is transmitted through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure.

In some embodiments, further comprising: a third semiconductor chip mounted on the upper surface and/or the lower surface of the first substrate; a first passive device mounted on the upper surface and/or the lower surface of the first substrate; a fourth semiconductor chip mounted on the upper surface and/or the lower surface of the second substrate; the second passive device is attached to the upper surface and/or the lower surface of the second substrate; when the third semiconductor chip and/or the first passive device are/is attached to the upper surface of the second substrate, the plastic layer also covers the third semiconductor chip and/or the first passive device; when the fourth semiconductor chip and/or the second passive device are/is mounted on the lower surface of the second substrate, the plastic layer is further formed with a containing groove for containing the fourth semiconductor chip and/or the second passive device.

Some embodiments of the present application further provide a method for forming a package structure, including:

providing a first substrate comprising opposite upper and lower surfaces, the first substrate having a first waveguide transmission structure formed therein;

forming a plastic layer covering the upper surface of the first substrate;

forming a rectangular waveguide in the plastic layer, wherein the rectangular waveguide is positioned above the first waveguide transmission structure;

Providing a second substrate, wherein the second substrate comprises an upper surface and a lower surface which are opposite, the second substrate is attached to the upper surface of the plastic sealing layer, a second waveguide transmission structure is formed in the second substrate, and the second waveguide transmission structure is positioned above the rectangular waveguide; a second semiconductor chip is attached to the upper surface of the second substrate, and the second semiconductor chip is electrically connected with the second waveguide transmission structure;

and a first semiconductor chip is mounted on the lower surface of the first substrate, the first semiconductor chip is electrically connected with the first waveguide transmission structure, the first semiconductor chip is used for generating a first millimeter wave radio frequency signal, the first millimeter wave radio frequency signal is transmitted to the second semiconductor chip to be received through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure, or the second semiconductor chip is used for generating a second millimeter wave radio frequency signal, and the second millimeter wave radio frequency signal is transmitted to the first semiconductor chip to be received through the second waveguide transmission structure, the rectangular waveguide and the first waveguide transmission structure.

the second waveguide transmission structure comprises a second upper metal layer, a second lower metal layer and a second cavity structure positioned between the second upper metal layer and the second lower metal layer, wherein the second upper metal layer is positioned on the upper surface of the second substrate, the second lower metal layer is positioned on the lower surface of the second substrate, a second gap groove is formed in the second lower metal layer and surrounded by an upper port of the rectangular waveguide, a second grounding coplanar waveguide is formed in the second upper metal layer, the second gap groove and the second grounding coplanar waveguide are respectively positioned below and above the second cavity structure, and the second semiconductor chip is electrically connected with the second grounding coplanar waveguide in the second waveguide transmission structure. In some embodiments, the forming of the first waveguide transfer structure includes: forming a first lower metal layer on the lower surface of the first substrate; forming a first grounded coplanar waveguide in the first lower metal layer; forming a plurality of first metal through hole structures which are arranged in an array in the first substrate, wherein the first metal through hole structures are electrically connected with the first lower metal layer, and the surrounding areas of the plurality of first metal through hole structures are first cavity structures; forming a first upper metal layer on the upper surface of the first substrate, wherein the first upper metal layer is electrically connected with the first metal through hole structure; forming a first slit groove in the first upper metal layer;

The forming process of the second waveguide transmission structure comprises the following steps: forming a second lower metal layer on the lower surface of the second substrate; forming a second slit groove in the second lower metal layer; forming a plurality of second metal through hole structures which are arranged in an array in the second substrate, wherein the second metal through hole structures are electrically connected with the second lower metal layer, and the area surrounded by the plurality of second metal through hole structures is a second cavity structure; forming a second upper metal layer on the upper surface of the second substrate, wherein the second upper metal layer is electrically connected with the second metal through hole structure; a second grounded coplanar waveguide is formed in the second upper metal layer.

In some embodiments, the forming of the first metal via structure includes: etching the first substrate to form a plurality of first through holes which are arranged in an array; filling metal into the first through hole to form a first metal through hole structure;

the forming process of the second metal through hole structure comprises the following steps: etching the second substrate to form a plurality of second through holes which are arranged in an array; and filling metal into the second through hole to form a second metal through hole structure.

In some embodiments, etching away a portion of the first upper metal layer forms the first slit groove; and etching and removing part of the second lower metal layer to form the second gap groove.

In some embodiments, the first grounded coplanar waveguide and the second grounded coplanar waveguide each include a feeder line and a third slot groove around the feeder line, etching away a portion of the first lower metal layer forms the third slot groove of the first grounded coplanar waveguide, and etching away a portion of the second upper metal layer forms the third slot groove of the second grounded coplanar waveguide.

In some embodiments, the rectangular waveguide is formed by: forming rectangular grooves penetrating through the upper surface and the lower surface of the plastic sealing layer in the plastic sealing layer; and forming a metal layer on the surfaces of the peripheral side walls of the rectangular grooves.

In some embodiments, the mold used in forming the molding layer has protrusions therein corresponding to the rectangular grooves, and after the molding layer is formed, the rectangular grooves are formed corresponding to the positions of the protrusions of the mold when the mold is removed.

In some embodiments, further comprising: a third semiconductor chip is attached to the upper surface and/or the lower surface of the first substrate; attaching a first passive device to the upper surface and/or the lower surface of the first substrate; mounting a fourth semiconductor chip on the upper surface and/or the lower surface of the second substrate; mounting a second passive device on the upper surface and/or the lower surface of the second substrate; when the third semiconductor chip and/or the first passive device are/is attached to the upper surface of the first substrate, the plastic layer also covers the third semiconductor chip and/or the first passive device; when the fourth semiconductor chip and/or the second passive device are/is mounted on the lower surface of the second substrate, the plastic layer is further formed with a containing groove for containing the fourth semiconductor chip and/or the second passive device.

The package structure and the forming method thereof in some embodiments of the present application include:

a first substrate; a first semiconductor chip mounted on the lower surface of the first substrate; the first waveguide transmission structure is positioned in the first substrate and is electrically connected with the first semiconductor chip; a molding layer covering the upper surface of the first substrate; a rectangular waveguide in the plastic layer, the rectangular waveguide being located above the first waveguide transmission structure; the second substrate is mounted on the upper surface of the plastic sealing layer and comprises an upper surface and a lower surface which are opposite; a second waveguide transmission structure located in the second substrate, and the second waveguide transmission structure is located above the rectangular waveguide; the second semiconductor chip is mounted on the upper surface of the second substrate, the second semiconductor chip is electrically connected with the second waveguide transmission structure, the first semiconductor chip is used for generating a first millimeter wave radio frequency signal, the first millimeter wave radio frequency signal is transmitted to the second semiconductor chip to be received through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure, or the second semiconductor chip is used for generating a second millimeter wave radio frequency signal, and the second millimeter wave radio frequency signal is transmitted to the first semiconductor chip to be received through the second waveguide transmission structure, the rectangular waveguide and the first waveguide transmission structure. The first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure can enable millimeter wave radio frequency signals to be transmitted in the direction from the first semiconductor chip on the lower surface of the first substrate to the second semiconductor chip on the upper surface of the second substrate or from the second semiconductor chip on the upper surface of the second substrate to the first semiconductor chip on the lower surface of the first substrate, low-loss transmission of high-frequency signals in the multilayer stacked structure from bottom to top (the direction from the first substrate to the second substrate) or from top to bottom (the direction from the second substrate to the first substrate) is facilitated, the first waveguide transmission structure and the second waveguide transmission structure are mirror structures relative to the rectangular waveguide, millimeter wave radio frequency signal transmission modes of the transmitting end and the receiving end are kept consistent (for example, the first semiconductor chip is used as the transmitting end of the millimeter wave radio frequency signals, the second semiconductor chip is correspondingly used as the receiving end of the radio frequency signals, or the second semiconductor chip is used as the transmitting end of the millimeter wave radio frequency signals, and the first semiconductor chip is correspondingly used as the receiving end of the millimeter wave radio frequency signals), and accuracy of millimeter wave radio frequency signal transmission is improved.

Drawings

FIG. 1 is a schematic diagram of a package structure according to some embodiments of the present application;

FIG. 2 is a schematic diagram of a first waveguide transmission structure according to some embodiments of the present application;

FIG. 3 is a schematic view of a first upper metal layer according to some embodiments of the present application;

FIG. 4 is a schematic diagram of a first lower metal layer according to some embodiments of the present application;

FIG. 5 is a schematic diagram of a second waveguide transmission structure according to some embodiments of the present application;

FIG. 6 is a schematic structural diagram of a package structure according to other embodiments of the present application;

fig. 7-11 are schematic structural diagrams illustrating a package structure forming process according to some embodiments of the present application.

Detailed Description

The following detailed description of specific embodiments of the present application refers to the accompanying drawings. In describing embodiments of the present application in detail, the schematic drawings are not necessarily to scale and are merely illustrative and should not be taken as limiting the scope of the present application. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.

Some embodiments of the present application first provide a package structure, referring to fig. 1, including:

a first substrate 101, the first substrate 101 including opposite upper and lower surfaces;

A first semiconductor chip 301 mounted on the lower surface of the first substrate 101;

a first waveguide transmission structure 201;

a plastic layer 104 covering the upper surface of the first substrate 101;

a rectangular waveguide 401 located in the plastic layer 104, and the rectangular waveguide 401 is located above the first waveguide transmission structure 201, the rectangular waveguide 401 includes opposite upper and lower ports, and the lower port of the rectangular waveguide 401 surrounds the first slot 207 of the first waveguide transmission structure 201;

a second substrate 112 mounted on the upper surface of the plastic sealing layer 104, wherein the second substrate 112 includes an upper surface and a lower surface opposite to each other;

a second waveguide transfer structure 212 located in the second substrate 112, and the second waveguide transfer structure 212 is located above the rectangular waveguide 401;

the second semiconductor chip 312 is mounted on the upper surface of the second substrate 112, the second semiconductor chip 312 is electrically connected with the second waveguide transmission structure 212, and the first semiconductor chip 301 is configured to generate a first millimeter wave radio frequency signal, where the first millimeter wave radio frequency signal is transmitted to the second semiconductor chip 312 through the first waveguide transmission structure 201, the rectangular waveguide 401 and the second waveguide transmission structure 212, or the second semiconductor chip 312 is configured to generate a second millimeter wave radio frequency signal, and the second millimeter wave radio frequency signal is transmitted to the first semiconductor chip 301 through the second waveguide transmission structure 212, the rectangular waveguide 401 and the first waveguide transmission structure 201.

Specifically, the first substrate 101 and the second substrate 112 are made of a material having a small loss of millimeter wave radio frequency signals (high frequency signals). In some embodiments, the first substrate 101 and the second substrate 112 may be a quartz substrate, a resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, or a Printed Circuit Board (PCB).

The first substrate 101 includes an upper surface and a lower surface opposite to each other, and in some embodiments, the upper surface and the lower surface of the first substrate each have a plurality of first pads 102, and the first substrate 101 may further have first electrical connection lines electrically connecting the first pads 102 on the upper surface of the first substrate with the corresponding first pads 102 on the lower surface, where the first electrical connection lines include one or more of metal wires, metal plugs, through hole electrical connection structures, and via hole electrical connection structures. In some embodiments, the upper surface and the lower surface of the first substrate 101 further have a first passivation layer 103 covering the surface of the first pad sidewall, and the material of the first passivation layer 103 may be an organic material (such as a resin) or an inorganic material (such as silicon nitride or silicon oxide).

The second substrate 112 includes opposite upper and lower surfaces, and in some embodiments, each of the upper and lower surfaces has a plurality of second pads (only the second pads 114 on the upper surface of the second substrate 112 are shown in fig. 1), and the second substrate 112 may further have second electrical connection lines therein for electrically connecting the pads 114 on the upper surface of the second substrate with corresponding second pads 114 on the lower surface, where the second electrical connection lines include one or more of metal lines, metal plugs, through-hole electrical connection structures, and via electrical connection structures. In some embodiments, the upper surface and the lower surface of the second substrate 112 further have a second passivation layer 111 covering the sidewall surface of the second pad 114, and the material of the second passivation layer 111 may be an organic material (such as a resin) or an inorganic material (such as silicon nitride or silicon oxide).

The first semiconductor chip 301 is mounted on the lower surface of the first substrate 101, the first semiconductor chip 301 is used for generating or receiving millimeter wave radio frequency signals, the second semiconductor chip 312 is mounted on the lower surface of the second substrate 101, and the second semiconductor chip 312 is used for generating or receiving millimeter wave radio frequency signals. In an embodiment, the first semiconductor chip 301 is configured to generate a first millimeter wave radio frequency signal, and the second semiconductor chip 312 is configured to receive the first millimeter wave radio frequency signal, and specifically, the first millimeter wave radio frequency signal generated by the first semiconductor chip 301 is transmitted to the second semiconductor chip 312 through the first waveguide transmission structure 201, the rectangular waveguide 401, and the second waveguide transmission structure 212. In another embodiment, the second semiconductor chip 312 is configured to generate a second millimeter wave radio frequency signal, and the first semiconductor chip 301 is configured to receive the second millimeter wave radio frequency signal, specifically, the second millimeter wave radio frequency signal generated by the second semiconductor chip 312 is transmitted to the first semiconductor chip 301 through the second waveguide transmission structure 212, the rectangular waveguide 401 and the first waveguide transmission structure 201. In other embodiments, the first semiconductor chip 301 may also have the function of generating and receiving millimeter-wave radio frequency signals (e.g., for generating a first millimeter-wave radio frequency signal and may also be the same as receiving a second millimeter-wave radio frequency signal), and the second semiconductor chip 312 may also have the function of generating and receiving millimeter-wave radio frequency signals (e.g., for generating a second millimeter-wave radio frequency signal and may also be the same as receiving a first millimeter-wave radio frequency signal). Therefore, in the present application, the first waveguide transmission structure 201, the rectangular waveguide 401 and the second waveguide transmission structure 212 may enable the millimeter wave radio frequency signal to be transmitted in the direction from the first semiconductor chip on the lower surface of the first substrate to the second semiconductor chip on the upper surface of the second substrate or from the second semiconductor chip on the upper surface of the second substrate to the first semiconductor chip on the lower surface of the first substrate, which is favorable for implementing low-loss transmission of the high frequency signal in the multilayer stacked structure from bottom to top (the direction of the first substrate to the second substrate) or from top to bottom (the direction of the second substrate to the direction of the first substrate), and the first waveguide transmission structure 201 and the second waveguide transmission structure 212 are mirror structures with respect to the rectangular waveguide 401, so that the millimeter wave radio frequency signal transmission mode between the transmitting end and the receiving end is kept consistent (for example, the first semiconductor chip 301 is used as the transmitting end of the radio frequency signal, the second semiconductor chip 312 is correspondingly used as the receiving end of the millimeter wave radio frequency signal, or the second semiconductor chip 312 is used as the transmitting end of the millimeter wave radio frequency signal, and the corresponding semiconductor chip 312 is used as the receiving end of the millimeter wave radio frequency signal, which is correspondingly used as the receiving end of the millimeter wave signal of the millimeter wave radio frequency signal).

In some embodiments, the first millimeter wave radio frequency signal and the second millimeter wave radio frequency signal have a frequency of 90GHz-110GHz and a wavelength of 2.7mm-3.3mm. The specific frequencies and specific wavelengths of the first millimeter wave radio frequency signal and the second millimeter wave radio frequency signal may be the same or different.

In some embodiments, with continued reference to fig. 1, the first semiconductor chip 301 is flip-chip mounted on the lower surface of the first substrate 101. In a specific embodiment, the first semiconductor chip 301 includes a functional surface and a back surface opposite to each other, and a first integrated circuit (not shown) having a specific function is formed in the first semiconductor chip 301, in this embodiment, the first semiconductor chip has at least a first integrated circuit capable of generating and/or receiving a millimeter wave radio frequency signal, and the functional surface of the first semiconductor chip has a first bonding bump 302, and the first bonding bump 302 is electrically connected to the first integrated circuit. The second semiconductor chip 312 is flip-chip mounted on the upper surface of the second substrate 112. In a specific embodiment, the second semiconductor chip 312 includes a functional surface and a back surface opposite to each other, and a second integrated circuit (not shown) having a specific function is formed in the second semiconductor chip 312, in this embodiment, the second semiconductor chip has at least a second integrated circuit capable of generating and/or receiving a millimeter wave radio frequency signal, and the functional surface of the second semiconductor chip has a second bonding bump 314, and the second bonding bump 314 is electrically connected to the second integrated circuit.

In some embodiments, the first soldering bump 302 and the second soldering bump 314 are solder bumps or include a metal bump and a solder bump on a top surface of the metal bump, where the metal bump is one or more of aluminum, nickel, tin, tungsten, platinum, copper, titanium, chromium, tantalum, gold, and silver, and the solder bump is one or more of tin, tin silver, tin lead, tin silver copper, tin silver zinc, tin bismuth indium, tin gold, tin copper, tin zinc indium, or tin silver antimony.

In some embodiments, when the first semiconductor chip 301 is flip-chip mounted on the lower surface of the first substrate 101, the functional surface of the first semiconductor chip 301 faces the lower surface of the first substrate 101, and a portion of the first bonding pad 302 of the first semiconductor chip 301 is bonded to a portion of the first bonding pad 102 of the lower surface of the first substrate 101, and a portion of the first bonding pad 302 of the first semiconductor chip 301 is bonded to the feeder line 208 (refer to fig. 1, 2 or 4) in the first grounded coplanar waveguide 210 in the first waveguide transmission structure 201, so that, on one hand, the (first) millimeter wave radio frequency signal generated by the first semiconductor chip 301 is transmitted to the first grounded coplanar waveguide 210 and is transmitted outwards through the first waveguide transmission structure 201, or the (second) radio frequency signal transmitted from the first grounded coplanar waveguide 210 is received, on the other hand, so that the first semiconductor chip 301 can simultaneously communicate with other devices. When the second semiconductor chip 312 is flip-chip mounted on the upper surface of the second substrate 112, the functional surface of the second semiconductor chip 312 faces the upper surface of the second substrate 112, a part of the second bonding pad 314 of the second semiconductor chip 312 is bonded to a part of the second bonding pad 114 of the lower surface of the second substrate 112, and a part of the second bonding pad 314 of the second semiconductor chip 312 is bonded to the feeder line 218 (refer to fig. 1 and 5) in the second grounded coplanar waveguide 220 in the second waveguide transmission structure 212, so that, on one hand, the second semiconductor chip 312 can receive the (first) millimeter wave radio frequency signal transmitted from the second grounded coplanar waveguide 220, or transmit the (second) millimeter wave radio frequency signal generated by the second semiconductor chip 312 to the second grounded coplanar waveguide 220 and transmit the (second) millimeter wave radio frequency signal to the outside through the second waveguide transmission structure 212, and on the other hand, so that the second semiconductor chip 312 can communicate with other devices at the same time.

The first substrate 101 is further provided with a first waveguide transmission structure 201, where the first waveguide transmission structure 201 is configured to transmit (a first) millimeter wave radio frequency signal generated by the first semiconductor chip 301 on the lower surface of the first substrate 101 to the direction of the second substrate 112 (for example, to the second semiconductor chip 312 on the second substrate 112) with less loss, or to transmit (a second) millimeter wave radio frequency signal transmitted from the direction of the second substrate 112 (for example, a second millimeter wave radio frequency signal generated by the second semiconductor chip 312) to the first semiconductor chip 301.

The first waveguide transmission structure 201 includes a first upper metal layer 203, a first lower metal layer 204, and a first cavity structure 205 located between the first upper metal layer 203 and the first lower metal layer 204, the first upper metal layer 203 is located on the upper surface of the first substrate 101, the first lower metal layer 204 is located on the lower surface of the first substrate 101, the first cavity structure 205 is located in the first substrate, the first upper metal layer 203 has a first slot groove 207 (refer to fig. 1 or fig. 2), the first lower metal layer 204 has a first grounded coplanar waveguide 210 (refer to fig. 2), the first slot groove 207 and the first grounded coplanar waveguide 210 are located above and below the first cavity structure 205, respectively, and the first waveguide transmission structure 201 is electrically connected with the first semiconductor chip 301 specifically: the first grounded coplanar waveguide 210 in the first waveguide transmission structure 201 is electrically connected to the first semiconductor chip 301.

Referring to fig. 1, 2 and 4 in combination, the first lower metal layer 204 is located on the lower surface of the first substrate 101, the first lower metal layer 204 is located on the same layer as the first pad 102 (referring to fig. 1) on the lower surface of the first substrate 101, the first lower metal layer 204 has a first grounded coplanar waveguide 210 (referring to fig. 2 and 4), and in some embodiments, the first grounded coplanar waveguide 210 is used to receive the (first) millimeter wave rf signal generated by the first semiconductor chip 301 and feed the first millimeter wave rf signal into the first cavityIn the structure 205, the first grounded coplanar waveguide 210 is also used for converting the transmission mode of the (first) millimeter wave radio frequency signal, such as from the quasi-TEM (quasi transverse electromagnetic) mode of the grounded coplanar waveguide to the main transmission mode TE of the rectangular waveguide ₁₀ Mode to reduce transmission loss of millimeter wave radio frequency signals. In other embodiments, the first grounded coplanar waveguide 210 may also be used to receive the (second) millimeter-wave rf signals transmitted in the first cavity structure 205 (the second millimeter-wave rf signals generated by the second semiconductor chip 312 on the second substrate 112) and transmit the received (second) millimeter-wave rf signals to the first semiconductor chip 301 for reception, where the first grounded coplanar waveguide 210 is also used for transmission mode conversion, such as the main transmission mode TE from a rectangular waveguide ₁₀ The mode is converted into a quasi-TEM (quasi transverse electromagnetic wave) mode of the grounded coplanar waveguide so as to reduce the transmission loss of millimeter wave radio frequency signals.

The first grounded coplanar waveguide 210 includes a feeder line 208 and a third slot 209 located around the feeder line 208.

In this embodiment, referring to fig. 2 and 4, the feeder 208 is in a shape of a "middle" and the "middle" feeder 208 has a metal body and two square openings 211 penetrating the metal body, and the "middle" feeder 208 has a third slot 209 around two sides of the "middle" feeder, and the first grounded coplanar waveguide 210 with the specific structure can enable the millimeter wave radio frequency signal transmission mode to be from a quasi-TEM (quasi transverse electromagnetic wave) mode to a TE mode ₁₀ Mode or slave TE ₁₀ Conversion of mode to lower power consumption of quasi-TEM (quasi transverse electromagnetic wave) mode.

In other embodiments, the feeder may be of a "racket" type, and the "racket" type feeder may include a spherical surface and a knob electrically connected to the spherical surface, the spherical surface having third slit grooves around the periphery and around both sides of the knob.

In some embodiments, referring to fig. 2, the first substrate 101 has a plurality of first metal via structures 206 arranged in an array, the upper and lower ends of the first metal via structures 206 are electrically connected to the first upper metal layer 203 and the first lower metal layer 204, respectively, and a region (a part of the first substrate material) surrounded by the plurality of first metal via structures 206 is the first cavity structure 205, the first cavity structure 205 is a resonant cavity, and the millimeter wave radio frequency signal is defined in the first cavity structure 205 for transmission. In some embodiments, the material of the first metal via structure 206 is one or more of Al, cu, ag, au, pt, ni, ti, tiN, taN, ta, taC, taSiN, W, WN, WSi.

Referring to fig. 1, 2 and 3 in combination, the first upper metal layer 203 is located on the upper surface of the first substrate 101, the first upper metal layer 203 and the bonding pad on the upper surface of the first substrate 101 are located on the same layer, and the first upper metal layer has a first slot 207 therein, where the first slot 207 is used to radiate (a) a (first) millimeter wave radio frequency signal transmitted in the first cavity structure 205 (into the rectangular waveguide 401 above the first cavity structure 205), or to receive (a second) millimeter wave radio frequency signal transmitted downward from the rectangular waveguide 401.

In this embodiment, referring to fig. 2 and fig. 3, the first slot 207 is in an "i" shape, and the first slot 207 with the specific structure can make the loss of the (first) millimeter wave radio frequency signal when radiating upward or the loss of the (first) millimeter wave radio frequency signal when receiving downward transmission, and when the "i" first slot 207 is matched with the "middle" feeder 208, the loss of the millimeter wave radio frequency signal when transmitting is further reduced (the insertion loss is less than or equal to-2 db and the return loss is less than or equal to-15 db when the millimeter wave radio frequency signal is transmitted through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure).

In other embodiments, the first slit groove may also have a "straight" shape, a "U" shape, or a "V" shape.

The second substrate 112 is provided with a second waveguide transmission structure 212, where the second waveguide transmission structure 212 is used for transmitting (first) millimeter wave radio frequency signals (such as first millimeter wave radio frequency signals generated by the first semiconductor chip 301) transmitted in the direction of the first substrate 101 to the second semiconductor chip 312, or for transmitting (second) millimeter wave radio frequency signals generated by the second semiconductor chip 312 on the upper surface of the second substrate 112 with less loss to the direction of the first substrate 101 (such as to the first semiconductor chip 301 on the lower surface of the first substrate 101).

Referring to fig. 1 and 5 in combination, the second waveguide transmission structure 212 includes a second upper metal layer 214, a second lower metal layer 213, and a second cavity structure 215 located between the second upper metal layer 214 and the second lower metal layer 213, where the second upper metal layer 214 is located on the upper surface of the second substrate 112, the second lower metal layer 213 is located on the lower surface of the second substrate 112, the second lower metal layer 213 has a second slot 217 therein, the second slot 217 is surrounded by the upper port of the rectangular waveguide 401, the second upper metal layer 214 has a second grounded coplanar waveguide 220 (referring to fig. 5), the second slot 217 and the second grounded coplanar waveguide 220 are located below and above the second cavity structure 215, respectively, and the second semiconductor chip 312 is electrically connected with the second waveguide transmission structure 212 specifically: the second semiconductor chip 312 is electrically connected to the second grounded coplanar waveguide 220 in the second waveguide transfer structure 212. The second waveguide transmission structure 212 and the first waveguide transmission structure 201 are mirror images of each other with respect to the rectangular waveguide 401, the structures of the second upper metal layer 214 and the second grounded coplanar waveguide 220 in the second waveguide transmission structure 212 are the same as those of the first lower metal layer 204 and the first grounded coplanar waveguide 210 in the first waveguide transmission structure 201, and the structures of the second upper metal layer 214 and the second slot 217 in the second waveguide transmission structure 212 are the same as those of the first upper metal layer 203 and the first slot 207 in the first waveguide transmission structure 201.

The second lower metal layer 213 is located on the lower surface of the second substrate 101, where the second lower metal layer 213 has a second slot 217 therein, and the second slot 217 is used to receive the (first) millimeter wave rf signal transmitted upward from the rectangular waveguide 401 or radiate the (first) millimeter wave rf signal transmitted in the second cavity structure 215 (into the rectangular waveguide 401 below the second cavity structure 215).

In this embodiment, referring to fig. 5, the second slot 217 is in an "i" shape, and the second slot 217 with the specific structure can make the loss of the (second) millimeter wave radio frequency signal smaller when radiating downward or smaller when receiving the (first) millimeter wave radio frequency signal transmitted upward, and when the "i" second slot 217 is matched with the "middle" feeder 218, the loss of the millimeter wave radio frequency signal when transmitting is further reduced (the insertion loss is less than or equal to-2 db and the return loss is less than or equal to-15 db when the millimeter wave radio frequency signal is transmitted through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure).

In other embodiments, the second slit groove may also have a "straight" shape, a "U" shape, or a "V" shape.

In some embodiments, referring to fig. 1 and fig. 5, the second substrate 112 has a plurality of second metal via structures 216 arranged in an array, upper and lower ends of the second metal via structures 216 are electrically connected to the second upper metal layer 214 and the second lower metal layer 213, respectively, and a region (a part of the second substrate material) surrounded by the plurality of second metal via structures 216 is the second cavity structure 215, the second cavity structure 215 is a resonant cavity, and the millimeter wave radio frequency signal is defined in the second cavity structure 215 for transmission. In some embodiments, the material of the second metal via structure 216 is one or more of Al, cu, ag, au, pt, ni, ti, tiN, taN, ta, taC, taSiN, W, WN, WSi.

The second upper metal layer 214 is located on the upper surface of the second substrate 112, and the second upper metal layer 214 has a second grounded coplanar waveguide 220 (refer to fig. 5) therein, and in some embodiments, the second grounded coplanar waveguide 220 is used to receive the (first) millimeter wave rf signal (the first millimeter wave rf signal generated by the first semiconductor chip 301 on the first substrate 101) transmitted upward in the second cavity structure 215, and transmit the received (first) millimeter wave rf signal to the second semiconductor chip 312 for reception, and the second grounded coplanar waveguide 220 is also used to perform conversion of transmission modes, such as TE in the main transmission mode of the rectangular waveguide ₁₀ Mode conversion to grounded coplanar waveguide quatsi-TEM (quasi transverse electromagnetic) mode to reduce transmission loss of millimeter wave radio frequency signals. In other embodiments, the second grounded coplanar waveguide 220 is further configured to receive a (second) millimeter-wave rf signal generated by the second semiconductor chip 312 and feed the second millimeter-wave rf signal into the second cavity structure 215, and the second grounded coplanar waveguide 220 is also configured to perform conversion of a transmission mode, such as from a quasi-TEM (quasi transverse electromagnetic wave) mode of the grounded coplanar waveguide to a main transmission mode TE of a rectangular waveguide ₁₀ Mode to reduce transmission loss of millimeter wave radio frequency signals.

Referring to fig. 5, the second grounded coplanar waveguide 220 includes a feeder line 218 and a third slot 219 located around the feeder line 218.

In some embodiments, the feeder 218 is in a shape of a "middle" and the "middle" feeder 218 has a metal body and two square openings 221 penetrating the metal body, and the "middle" feeder 218 has a third slot 219 around two sides of the "middle" feeder 218, and the second grounded coplanar waveguide 220 with the specific structure can enable the millimeter wave radio frequency signal transmission mode from a quasi-TEM (quasi transverse electromagnetic wave) mode to a TE ₁₀ Mode (or from TE ₁₀ Mode to quasi-TEM (quasi transverse electromagnetic wave) mode) lower power consumption.

With continued reference to fig. 1, the upper surface of the first substrate 101 is further covered with a (first) plastic sealing layer 104, where the plastic sealing layer 104 has a rectangular waveguide 401, the rectangular waveguide 401 includes an upper port and a lower port that are opposite, the lower port of the rectangular waveguide 401 surrounds the first slot 207 of the first waveguide transmission structure 201, and the lower port of the rectangular waveguide 401 surrounds the second slot 207 of the second waveguide transmission structure 212. The rectangular waveguide 401 may transmit the (first) millimeter wave radio frequency signal transmitted by the first waveguide transmission structure 201 upward into the second waveguide transmission structure 212, or may transmit the (second) millimeter wave radio frequency signal transmitted by the second waveguide transmission structure 212 downward into the first waveguide transmission structure 201.

The dimensions of the lower port and the upper port of the rectangular waveguide 401 are the same. The rectangular waveguide 401 includes a rectangular groove 403 located in the plastic sealing layer 104 and penetrating the upper and lower surfaces of the plastic sealing layer 104, and a metal layer 402 located on the peripheral sidewall surfaces of the rectangular groove 403. In some embodiments, the rectangular slot 403 is air, and the metal layer 402 is made of one or more of copper, aluminum, nickel, tin, tungsten, platinum, titanium, chromium, tantalum, gold, and silver.

In some embodiments, the rectangular waveguide 401 adopts the WR8 standard, and the transmission mode in the rectangular waveguide 401 is TE ₁₀ 。

In some embodiments, the material of the plastic layer 104 is a filler-containing epoxy resin, polyimide resin, benzocyclobutene resin, or polybenzoxazole resin; or may be a filled polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polyethylene, polypropylene, polyolefin, polyurethane, polyolefin, polyethersulfone, polyamide, polyurethane, ethylene-vinyl acetate copolymer or polyvinyl alcohol. The filler may be an inorganic filler or an organic filler.

In some embodiments, further comprising: is positioned on the upper surface of the second substrate 112 and covers the second molding layer 116 of the second semiconductor chip 312. The material of the second plastic layer 116 may be the same as or different from the material of the first plastic layer 104.

In some embodiments, further comprising: and an external bump 105 protruding from the lower surface of the first substrate 101 and electrically connected to a portion of the first pad 102, where the external bump 105 is used for electrically connecting a package structure with an external device (such as another package structure, another substrate or a chip). In a specific embodiment, the external protrusion 105 is a solder protrusion, and the material of the external protrusion 105 is one or more of tin, tin-silver, tin-lead, silver-copper, tin-silver-zinc, tin-bismuth-indium, tin-gold, tin-copper, tin-zinc-indium, or tin-silver-antimony.

In some embodiments, referring to fig. 6, the package structure further comprises: a third semiconductor chip 313 mounted on the upper surface and/or the lower surface of the first substrate 101, the second semiconductor chip 313 is electrically connected to the first substrate 101, and in a specific embodiment, the upper surface or the lower surface of the first substrate 101 is mounted with the third semiconductor chip 313, or the upper surface and the lower surface of the first substrate 101 are both mounted with the third semiconductor chip (taking the upper surface of the first substrate 101 mounted with one third semiconductor chip 313 as an example in fig. 6, the third semiconductor chip 313 may be soldered with a corresponding first pad 102 on the upper surface of the first substrate 101 by a soldering bump 315); the first passive device 502 is mounted on the upper surface and/or the lower surface of the first substrate 101, where the first passive device 502 is electrically connected to the first substrate 101, and the first passive device 502 may be one or several of a resistor, a capacitor, and an inductor, and in a specific embodiment, the upper surface or the lower surface of the first substrate 101 is mounted on the first passive device 502, or the upper surface and the lower surface of the first substrate 101 are both mounted on the first passive device (in fig. 6, the upper surface of the first substrate 101 is mounted on the first passive device 502 as an example); a fourth semiconductor chip (not shown) mounted on the upper surface and/or the lower surface of the second substrate 112, the fourth semiconductor chip being electrically connected to the second substrate 112, the fourth semiconductor chip being mounted on the upper surface or the lower surface of the second substrate 112, or the fourth semiconductor chip being mounted on both the upper surface and the lower surface of the second substrate 112; a second passive device 501 mounted on the upper surface and/or the lower surface of the second substrate 112, where the second passive device 501 is electrically connected to the second substrate 112, and the second passive device 501 may be one or more of a resistor, a capacitor, and an inductor, and in a specific embodiment, the upper surface or the lower surface of the second substrate 112 is mounted with the second passive device 501, or both the upper surface and the lower surface of the second substrate 112 are mounted with the second passive device 501 (in fig. 6, the lower surface of the second substrate 112 is mounted with one second passive device 501 as an example)

In some embodiments, with continued reference to fig. 6, when the third semiconductor chip 313 and/or the first passive device 502 is mounted on the upper surface of the first substrate, the molding layer 104 also covers the third semiconductor chip 313 and/or the first passive device 502. In other embodiments, when the fourth semiconductor chip (not shown) and/or the second passive device 501 are mounted on the lower surface of the second substrate 112, the molding layer 104 is further formed with a receiving groove 106 for receiving the fourth semiconductor chip and/or the second passive device 501.

In this application, the millimeter wave radio frequency signal in the package structure is transmitted between the first substrate 101 and the second substrate 112 through the first waveguide transmission structure 201, the rectangular waveguide 401 and the second waveguide transmission structure 212, where the millimeter wave radio frequency signal includes a first millimeter wave radio frequency signal generated by the first semiconductor chip 301 and/or a second millimeter wave radio frequency signal generated by the second semiconductor chip 312. In some embodiments, the process of first millimeter wave radio frequency signal transmission includes: the first semiconductor chip 301 generates a first millimeter wave radio frequency signal; the first grounded coplanar waveguide 210 receives a first millimeter wave radio frequency signal generated by the first semiconductor chip 301, feeds the first millimeter wave radio frequency signal into the first cavity structure 205, and transmits the fed first millimeter wave radio frequency signal to the first slot 207 through the first cavity structure 205 and radiates the first millimeter wave radio frequency signal into the rectangular waveguide 401 through the first slot 207 for transmission; the second slot 217 receives the first millimeter wave rf signal transmitted from the upper port of the rectangular waveguide and couples the received first millimeter wave rf signal into the second cavity structure 215 for transmission to the second grounded coplanar waveguide 220; the second semiconductor chip 312 receives the first millimeter wave radio frequency signal transmitted in the second grounded coplanar waveguide 220.

In another embodiment, the second millimeter wave radio frequency signal transmission process includes: the second semiconductor chip 312 generates a second millimeter wave radio frequency signal; the second grounded coplanar waveguide 220 receives a second millimeter wave radio frequency signal generated by the second semiconductor chip 312, feeds the second millimeter wave radio frequency signal into the second cavity structure 215, and transmits the fed second millimeter wave radio frequency signal to the second slot 217 through the second cavity structure 215 and radiates into the rectangular waveguide 401 through the second slot 217 for transmission; the first slot 207 receives the second millimeter wave rf signal transmitted from the lower port of the rectangular waveguide 401, and couples the received second millimeter wave rf signal into the first cavity structure 205 for transmission to the first grounded coplanar waveguide 210; the first semiconductor chip 301 receives the first millimeter wave radio frequency signal transmitted in the first grounded coplanar waveguide 210.

Some embodiments of the present application further provide a method for forming a package structure, and the method is described in detail below with reference to the accompanying drawings.

Referring to fig. 7, a first substrate 101 is provided, the first substrate 101 including opposite upper and lower surfaces, the first substrate 101 having a first waveguide transmission structure 201 formed therein.

In some embodiments, the first waveguide transmission structure 201 includes a first upper metal layer 203, a first lower metal layer 204, and a first cavity structure 205 located between the first upper metal layer 203 and the first lower metal layer 204, the first upper metal layer 203 is located on an upper surface of the first substrate 101, the first lower metal layer 204 is located on a lower surface of the first substrate 101, the first upper metal layer 203 has a first slot 207 therein, the first lower metal layer 204 has a first grounded coplanar waveguide 210 therein (refer to fig. 2), and the first slot 207 and the first grounded coplanar waveguide 210 are located above and below the first cavity structure 205, respectively.

The forming process of the first waveguide transmission structure 201 includes: forming a first lower metal layer 204 on a lower surface of the first substrate 101, the first lower metal layer 204 being formed by a sputtering, electroplating or deposition process; forming a first grounded coplanar waveguide 210 in the first lower metal layer 204, the first grounded coplanar waveguide 210 including a feeder line 208 and a third slot groove 209 (refer to fig. 2) located around the feeder line 208, the third slot groove 209 and the feeder line 208 being formed by etching away a portion of the first lower metal layer 204; a plurality of first metal via structures 206 arranged in an array are formed in the first substrate 101, the first metal via structures 206 are electrically connected to the first lower metal layer 204, and a region surrounded by the plurality of first metal via structures 206 is a first cavity structure 205, in an embodiment, the forming process of the first metal via structures 206 includes: etching the first substrate 101, forming a plurality of first through holes which are arranged in an array and penetrate through the upper surface and the lower surface of the first substrate 101 in the first substrate 101, filling metal into the first through holes to form a first metal through hole structure 206, wherein the metal filling process comprises a deposition (or sputtering) process and a planarization process, and the metal material can be one or more of Al, cu, ag, au, pt, ni, ti, tiN, taN, ta, taC, taSiN, W, WN, WSi; forming a first upper metal layer 203 on the upper surface of the first substrate 101, wherein the first upper metal layer 203 is electrically connected with the first metal via structure 206; a first slit groove 207 is formed in the first upper metal layer 203, and in an embodiment, etching away a portion of the first upper metal layer 203 forms the first slit groove 207. Note that, the first upper metal layer 203 may be performed before or after the first lower metal layer 204 is formed, and the first metal via structure 206 may be performed before or after one of the first upper metal layer 203 and the first lower metal layer 204 is formed.

In some embodiments, etching to remove a portion of the first upper metal layer 203 while forming the first grounded coplanar waveguide 210, and forming a first pad on the upper surface of the first substrate 101; simultaneously with the formation of the first slit groove 207, a portion of the first lower metal layer 204 is etched away, and a first pad 102 is formed on the lower surface of the first substrate 101.

Referring to fig. 8, a molding layer 104 is formed to cover the upper surface of the first substrate 101; a rectangular waveguide 401 is formed in the plastic layer 104, and the rectangular waveguide 401 is located above the first waveguide transfer structure 201.

In some embodiments, the rectangular waveguide 401 includes opposite upper and lower ports, the lower port of the rectangular waveguide 401 surrounding the first slot 207 of the first waveguide transport structure 201. The rectangular waveguide 401 includes a rectangular groove 403 located in the plastic sealing layer 104 and penetrating the upper and lower surfaces of the plastic sealing layer 104, and a metal layer 402 located on the peripheral sidewall surfaces of the rectangular groove 403.

Forming the plastic layer 104 includes an injection molding or rotational molding process. In forming the plastic layer 104, rectangular grooves 403 are simultaneously formed in the plastic layer 104 by a specific mold. Specific: the mold used in forming the molding layer 104 has a first protrusion corresponding to the rectangular groove 403, and after the molding layer 104 is formed, the rectangular groove 403 is formed correspondingly at the position of the first protrusion of the mold when the mold is removed, thereby simplifying the manufacturing process of the rectangular waveguide 401. In other embodiments, the molding layer 104 further includes a receiving groove 106 (refer to fig. 6), where the receiving groove 106 penetrates through the upper surface of the molding layer 104, and the receiving groove 106 is configured to receive the fourth semiconductor chip and/or the second passive device 50 (refer to fig. 6) mounted on the lower surface of the second substrate 112 when the second substrate 112 is mounted on the molding layer 104, and to expand the functions of the package structure and reduce the volume of the package structure. The mold used in forming the plastic layer 104 further has a second protrusion corresponding to the accommodating groove 106, and after the plastic layer 104 is formed, the second protrusion of the mold is correspondingly positioned to form the accommodating groove 106 when the mold is removed, thereby simplifying the packaging process.

In one embodiment, the rectangular waveguide 401 is formed by: forming rectangular grooves 403 penetrating the upper and lower surfaces of the plastic layer 104 in the plastic layer 104; a metal layer 402 is formed on the peripheral sidewall surface of the rectangular groove 403. In a specific embodiment, the forming process of the metal layer 402 includes: forming a metal film on the side wall and bottom surface of the rectangular groove 403 and the upper surface of the plastic layer 104, wherein the metal film is made of one or more of copper, aluminum, nickel, tin, tungsten, platinum, titanium, chromium, tantalum, gold and silver, and the forming process is sputtering; and etching to remove the bottom surface of the rectangular groove 403 and the upper surface of the plastic sealing layer 104 to form a metal film, and exposing the metal film on the side wall of the rectangular groove 403 to form the metal layer 402.

Referring to fig. 9, a second substrate 112 is provided, the second substrate 112 includes opposite upper and lower surfaces, a second waveguide transmission structure 212 is formed in the second substrate 112, and the second waveguide transmission structure 212 is located above the rectangular waveguide 401; a second semiconductor chip 312 is attached to the upper surface of the second substrate 112, and the second semiconductor chip 312 is electrically connected to the second waveguide transmission structure 212.

In some embodiments, the second waveguide transmission structure 212 includes a second upper metal layer 214, a second lower metal layer 213, and a second cavity structure 215 located between the second upper metal layer 214 and the second lower metal layer 213, the second upper metal layer 214 is located on the upper surface of the second substrate 112, the second lower metal layer 213 is located on the lower surface of the second substrate 112, the second lower metal layer 213 has a second slot 217 therein, the second slot 217 is subsequently surrounded by the upper port of the rectangular waveguide 401, the second upper metal layer 214 has a second grounded coplanar waveguide 220 therein (refer to fig. 5), the second slot 217 and the second grounded coplanar waveguide 220 are located below and above the second cavity structure 215, respectively, and the second semiconductor chip 312 is electrically connected with the second waveguide transmission structure 212 specifically: the second semiconductor chip 312 is electrically connected to the second grounded coplanar waveguide 220 in the second waveguide transfer structure 212.

In some embodiments, the forming of the second waveguide transfer structure 212 includes: forming a second lower metal layer 213 on a lower surface of the second substrate 112, the second lower metal layer 213 being formed by a sputtering, electroplating or deposition process; forming a second slit groove 217 in the second lower metal layer 213, and in an embodiment, etching away a portion of the second lower metal layer 213 to form the second slit groove 217; a plurality of second metal via structures 216 are formed in the second substrate 212 and arranged in an array, the second metal via structures 216 are electrically connected to the second lower metal layer 213, and a region surrounded by the plurality of second metal via structures 216 is a second cavity structure 215, in an embodiment, the forming process of the second metal via structures 216 includes: etching the second substrate 212, and forming a plurality of second through holes arranged in an array on the second substrate 212; filling the second through hole with metal to form a second metal through hole structure 216, wherein the process of filling the second through hole with metal comprises a deposition (or sputtering) process and a planarization process, and the material of the metal can be one or more than one of Al, cu, ag, au, pt, ni, ti, tiN, taN, ta, taC, taSiN, W, WN, WSi; forming a second upper metal layer 214 on the upper surface of the second substrate 212, wherein the second upper metal layer 214 is electrically connected with the second metal via structure 216; a second grounded coplanar waveguide 220 is formed in the second upper metal layer 214, the second grounded coplanar waveguide 220 including a feeder line 218 and a third slot 219 (refer to fig. 5) located around the feeder line 218, and the third slot 219 and the feeder line 218 are formed by etching away a portion of the second upper metal layer 214.

In some embodiments, the second grounding coplanar waveguide 220 is formed simultaneously with etching away a portion of the first upper metal layer 214, forming a second pad 114 on the upper surface of the second substrate 112; simultaneously with forming the second slit groove 217, etching and removing part of the second lower metal layer 213, and forming a second pad on the lower surface of the second substrate 112.

In some embodiments, the second semiconductor chip 312 is flip-chip mounted on the upper surface of the second substrate 112.

In an embodiment, further comprising: a second molding layer 116 is formed on the upper surface of the second substrate 112 to cover the second semiconductor chip 312.

Referring to fig. 10, the second substrate 112 is mounted on the upper surface of the plastic layer 104.

In some embodiments, an adhesive layer (not shown) is formed on a portion of the lower surface of the second substrate 112 before the second substrate 112 is mounted on the upper surface of the molding layer 104, and the second substrate 112 is mounted on the upper surface of the molding layer 104 through the adhesive layer.

Referring to fig. 11, a first semiconductor chip 301 is mounted on the lower surface of the first substrate 101, the first semiconductor chip 301 is electrically connected to the first waveguide transmission structure 201, and the first semiconductor chip 301 is configured to generate a first millimeter wave radio frequency signal, where the first millimeter wave radio frequency signal is transmitted to the second semiconductor chip 312 through the first waveguide transmission structure 201, the rectangular waveguide 401, and the second waveguide transmission structure 212, or the second semiconductor chip 312 is configured to generate a second millimeter wave radio frequency signal, where the second millimeter wave radio frequency signal is transmitted to the first semiconductor chip 301 through the second waveguide transmission structure 212, the rectangular waveguide 401, and the first waveguide transmission structure 201.

The electrical connection between the first semiconductor chip 301 and the first waveguide transmission structure 201 is specifically: the first grounded coplanar waveguide 210 in the first waveguide transmission structure 201 is electrically connected to the first semiconductor chip 301. In some embodiments, the first semiconductor chip 301 is flip-chip mounted on the lower surface of the first substrate 101.

In some embodiments, further comprising: an external bump 105 electrically connected to a portion of the first pad 102 is formed on the lower surface of the first substrate 101.

In some embodiments, referring to fig. 6, in the forming process of the foregoing package structure, the method further includes: a third semiconductor chip 313 is mounted on the upper surface and/or the lower surface of the first substrate 101; attaching a first passive device 502 to the upper surface and/or the lower surface of the first substrate 101; mounting a fourth semiconductor chip (not shown) on the upper surface and/or the lower surface of the second substrate 112; mounting a second passive device 501 on the upper surface and/or the lower surface of the second substrate 112; when the third semiconductor chip 313 and/or the first passive device 502 are mounted on the upper surface of the first substrate, the molding layer 104 also covers the third semiconductor chip 313 and/or the first passive device 502; when the fourth semiconductor chip and/or the second passive device 501 is mounted on the lower surface of the second substrate 112, the molding layer 106 is further formed with a receiving groove 106 for receiving the fourth semiconductor chip and/or the second passive device 501.

It should be noted that the terms "comprising" and "having," and variations thereof, as referred to in this disclosure are intended to cover non-exclusive inclusion. The terms "first," "second," and the like are used to distinguish similar objects and not necessarily to describe a particular order or sequence unless otherwise indicated by context, it should be understood that the data so used may be interchanged where appropriate. In addition, embodiments of the present disclosure and features of embodiments may be combined with each other without conflict. In addition, in the above description, descriptions of well-known components and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. In the foregoing embodiments, each embodiment is mainly described for the differences from the other embodiments, and the same/similar parts between the embodiments need to be referred to (or referred to) each other.

Although the present invention has been described with respect to the preferred embodiments, it is not intended to limit the scope of the invention, and any person skilled in the art may make any possible variations and modifications to the technical solution of the present invention using the methods and technical matters disclosed above without departing from the spirit and scope of the present invention, so any simple modifications, equivalent variations and modifications to the above embodiments according to the technical matters of the present invention fall within the scope of the technical matters of the present invention.

Claims

1. A package structure, comprising:

a first substrate including opposite upper and lower surfaces;

a first semiconductor chip mounted on the lower surface of the first substrate;

a first waveguide transmission structure in the first substrate, the first waveguide transmission structure and the first substrate

The first semiconductor chip is electrically connected;

a molding layer covering the upper surface of the first substrate;

2. The package structure of claim 1, wherein the first waveguide transmission structure comprises a first upper metal layer, a first lower metal layer, and a first cavity structure between the first upper metal layer and the first lower metal layer, the first upper metal layer being located on an upper surface of the first substrate, the first lower metal layer being located on a lower surface of the first substrate, the first upper metal layer having a first slot therein, the first lower metal layer having a first grounded coplanar waveguide therein, the first slot and first grounded coplanar waveguide being located above and below the first cavity structure, respectively, the first grounded coplanar waveguide in the first waveguide transmission structure being electrically connected to the first semiconductor chip;

3. The package structure according to claim 2, wherein the process of the first millimeter wave radio frequency signal transmission includes: the first semiconductor chip generates a first millimeter wave radio frequency signal; the first grounding coplanar waveguide receives a first millimeter wave radio frequency signal generated by the first semiconductor chip, feeds the first millimeter wave radio frequency signal into the first cavity structure, and transmits the fed first millimeter wave radio frequency signal to the first slot groove through the first cavity structure and radiates into the rectangular waveguide through the first slot groove for transmission; the second slot groove receives a first millimeter wave radio frequency signal transmitted and output from the upper port of the rectangular waveguide, and couples the received first millimeter wave radio frequency signal into a second cavity structure to be transmitted to the second grounded coplanar waveguide; the second semiconductor chip receives the first millimeter wave radio frequency signal transmitted in the second grounded coplanar waveguide.

4. The package structure according to claim 2, wherein the process of the second millimeter wave radio frequency signal transmission includes: the second semiconductor chip generates a second millimeter wave radio frequency signal; the second grounding coplanar waveguide receives a second millimeter wave radio frequency signal generated by the second semiconductor chip, feeds the second millimeter wave radio frequency signal into the second cavity structure, and transmits the fed second millimeter wave radio frequency signal to the second slot groove through the second cavity structure and radiates into the rectangular waveguide through the second slot groove for transmission; the first slot groove receives a second millimeter wave radio frequency signal transmitted from the lower port of the rectangular waveguide, and couples the received second millimeter wave radio frequency signal into a first cavity structure to be transmitted to the first grounded coplanar waveguide; the first semiconductor chip receives a first millimeter wave radio frequency signal transmitted in the first grounded coplanar waveguide.

5. The package structure of claim 2, wherein the first substrate has a plurality of first metal via structures arranged in an array, upper and lower ends of the first metal via structures are respectively electrically connected to the first upper metal layer and the first lower metal layer, and a region surrounded by the plurality of first metal via structures is a first cavity structure; the second substrate is internally provided with a plurality of second metal through hole structures which are arranged in an array manner, the upper end and the lower end of each second metal through hole structure are respectively and electrically connected with the second upper metal layer and the second lower metal layer, and a plurality of areas surrounded by the second metal through hole structures are second cavity structures.

6. The package structure according to claim 2 or 5, wherein the first slit groove and the second slit groove have the same structural shape, and the first slit groove and the second slit groove are in an "i" shape, a "one" shape, a "U" shape or a "V" shape.

7. The package structure according to claim 2 or 5, wherein the first grounded coplanar waveguide and the second grounded coplanar waveguide have the same structure, and each of the first grounded coplanar waveguide and the second grounded coplanar waveguide includes a feeder line and a third slot groove around the feeder line.

8. The package structure of claim 7, wherein the feed line is "medium" or "racket" shaped.

9. The package structure of claim 7, wherein the upper port of the rectangular waveguide has the same size as the lower port of the second cavity structure.

10. The package structure of claim 9, wherein the rectangular waveguide comprises rectangular grooves in the plastic layer and penetrating the upper and lower surfaces of the plastic layer, and a metal layer on the peripheral sidewall surfaces of the rectangular grooves.

11. The package structure of claim 9, wherein the first millimeter wave radio frequency signal and the second millimeter wave radio frequency signal have a frequency of 90GHz-110GHz and a wavelength of 2.7mm-3.3mm.

12. The package structure of claim 11, wherein when the first slot is in an "i" shape and the feeder is in a "n" shape, the insertion loss is less than or equal to-2 db and the return loss is less than or equal to-15 db when the first millimeter wave radio frequency signal or the second millimeter wave radio frequency signal is transmitted through the first waveguide transmission structure, the rectangular waveguide and the second waveguide transmission structure.

13. The package structure of claim 1, further comprising: a third semiconductor chip mounted on the upper surface and/or the lower surface of the first substrate; a first passive device mounted on the upper surface and/or the lower surface of the first substrate; a fourth semiconductor chip mounted on the upper surface and/or the lower surface of the second substrate; the second passive device is attached to the upper surface and/or the lower surface of the second substrate; when the third semiconductor chip and/or the first passive device are/is attached to the upper surface of the second substrate, the plastic layer also covers the third semiconductor chip and/or the first passive device; when the fourth semiconductor chip and/or the second passive device are/is mounted on the lower surface of the second substrate, the plastic layer is further formed with a containing groove for containing the fourth semiconductor chip and/or the second passive device.

14. The method for forming the packaging structure is characterized by comprising the following steps:

forming a plastic layer covering the upper surface of the first substrate;

15. The method of claim 14, wherein the first waveguide transmission structure comprises a first upper metal layer, a first lower metal layer, and a first cavity structure between the first upper metal layer and the first lower metal layer, the first upper metal layer being located on an upper surface of the first substrate, the first lower metal layer being located on a lower surface of the first substrate, the first upper metal layer having a first slot therein, the first lower metal layer having a first grounded coplanar waveguide therein, the first slot and the first grounded coplanar waveguide being located above and below the first cavity structure, respectively, the first grounded coplanar waveguide in the first waveguide transmission structure being electrically connected to the first semiconductor chip;

16. The method of forming a package structure of claim 15, wherein the forming the first waveguide transfer structure comprises: forming a first lower metal layer on the lower surface of the first substrate; forming a first grounded coplanar waveguide in the first lower metal layer; forming a plurality of first metal through hole structures which are arranged in an array in the first substrate, wherein the first metal through hole structures are electrically connected with the first lower metal layer, and the surrounding areas of the plurality of first metal through hole structures are first cavity structures; forming a first upper metal layer on the upper surface of the first substrate, wherein the first upper metal layer is electrically connected with the first metal through hole structure; forming a first slit groove in the first upper metal layer;

17. The method of forming a package structure of claim 16, wherein the forming of the first metal via structure comprises: etching the first substrate to form a plurality of first through holes which are arranged in an array; filling metal into the first through hole to form a first metal through hole structure;

18. The package structure of claim 16, wherein etching away a portion of the first upper metal layer forms the first slit groove; and etching and removing part of the second lower metal layer to form the second gap groove.

19. The method of forming a package structure of claim 16, wherein the first grounded coplanar waveguide and the second grounded coplanar waveguide each include a feed line and a third slot located around the feed line, etching away a portion of the first lower metal layer forms the third slot of the first grounded coplanar waveguide, and etching away a portion of the second upper metal layer forms the third slot of the second grounded coplanar waveguide.

20. The method of forming a package structure according to claim 15, wherein the forming process of the rectangular waveguide is: forming rectangular grooves penetrating through the upper surface and the lower surface of the plastic sealing layer in the plastic sealing layer;

and forming a metal layer on the surfaces of the peripheral side walls of the rectangular grooves.

21. The method of claim 20, wherein the mold used in forming the molding layer has protrusions corresponding to the rectangular grooves, and wherein the rectangular grooves are formed corresponding to the protrusions of the mold when the mold is removed after the molding layer is formed.

22. The method of forming a package structure of claim 14, further comprising: a third semiconductor chip is attached to the upper surface and/or the lower surface of the first substrate; attaching a first passive device to the upper surface and/or the lower surface of the first substrate; mounting a fourth semiconductor chip on the upper surface and/or the lower surface of the second substrate; mounting a second passive device on the upper surface and/or the lower surface of the second substrate; when the third semiconductor chip and/or the first passive device are/is attached to the upper surface of the first substrate, the plastic layer also covers the third semiconductor chip and/or the first passive device;

When the fourth semiconductor chip and/or the second passive device are/is mounted on the lower surface of the second substrate, the plastic layer is further formed with a containing groove for containing the fourth semiconductor chip and/or the second passive device.