Ultra-wideband interface for integrated circuits

Abstract

An external port with a waveguide port for bidirectional ultra-wideband transmission of radio frequency (RF) signals in an integrated circuit (IC) package is provided. [Solution] An external port (100) for bidirectional transmission of radio frequency (RF) signals in an integrated circuit (IC) package, the IC package (1000) including a case (1010) having an access wall (1020) and an IC chip (1030) mounted on a first substrate (1040) housed within the case (1010), the external port (100) including a dielectric waveguide structure (IC DRW 1) embeddable in the access wall (1020) of the case, the dielectric waveguide structure (IC DRW 1) configured for bidirectional transmission of RF signals.

Description

[Technical Field]

[0001] The present invention relates to an external port for bidirectional ultra-wideband transmission of radio frequency (RF) signals in an integrated circuit (IC) package. [Background technology]

[0002] In recent years, solid-state semiconductor devices have pushed the frequency limits to higher and higher frequencies, steadily increasing their adoption in various terahertz (THz) applications, such as communications, metrology, imaging, and sensing. Because a suitable housing is key to improving the stability and reliability of integrated circuits (ICs), several packaging strategies have been explored. As frequencies increase, interconnections between ICs become more challenging due to the effects of manufacturing tolerances on loss and signal integrity.

[0003] For ICs operating at frequencies below 30 GHz, the use of plastic molded packages is well established. Interconnections are made via beam leads or balls, typically in a ground-signal-ground configuration, forming a coplanar waveguide (CPW). Internally, IC chips are interconnected to pads by wire or ribbon bonding. However, as frequencies increase, parasitic series inductance becomes significant, making this technology unusable for millimeter-wave and submillimeter-wave frequencies. While other technologies, such as low-temperature co-fired ceramics (LTCC) and multiple wire bonds per connection point, can partially mitigate losses, they still have practical limitations at submillimeter-wave frequencies.

[0004] Other waveguides can be used for interconnects, but, like coaxial cables, they are too large to be practical at frequencies above 100 GHz, or, like rectangular waveguides, are not suitable for integration into IC packages. The use of integrated antennas for chip-to-chip communication has also been proposed. This solution fits easily within standard plastic packages, but is limited in frequency by the chosen antenna topology. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention overcomes the aforementioned limitations and drawbacks. [Means for solving the problem]

[0006] Our current approach is shown in Figure 1. A single-mode excited dielectric waveguide provides a low-loss, high-frequency, ultra-wideband signal interconnect. The rod is cut and installed in the IC package wall as a bidirectional high-frequency port, which can be used to connect an external dielectric waveguide, an antenna, or another IC.

[0007] The present invention provides a solution for bidirectional ultra-wideband transmission of radio frequency (RF) signals in an integrated circuit (IC) package. The present invention is adaptable to a variety of integrated circuit package configurations.

[0008] Specifically, the present invention relates to an external port comprising at least a waveguide port for bidirectional transmission of radio frequency (RF) signals in an integrated circuit (IC) package. Since any signal coupled into the external port can be efficiently coupled to another dielectric structure, a waveguide, an antenna, or a resonator, the external port of the present invention can be used to realize communication devices and high frequency sensors. Dielectric waveguide structures can be used for either radiation or reception through the proposed IC port.

[0009] Our invention has the following improvements:

[0010] The external port of the present invention is a novel ultra-wideband signal port that can be integrated into existing IC packages. Depending on the device configuration, a large number of external ports can be mounted on a single package.

[0011] The external port of the present invention comprises a dielectric waveguide structure, for example, a dielectric rod waveguide (DRW), which is incorporated into an IC package. The dielectric waveguide structure can be made of a high-dielectric-constant substrate such as silicon, GaAs, or InP. On the external side, the dielectric waveguide structure can be cut flat. On the internal side, the dielectric waveguide structure can be connected to an IC chip.

[0012] The external port of the present invention may have a lower cutoff frequency depending on the cross-sectional dimensions of the port, for example a 1 mm width would have a cutoff frequency of about 65 GHz.

[0013] The external ports of the present invention can have high cutoff frequencies of at least 100 GHz or higher, depending on manufacturing tolerances, allowing a trade-off between manufacturing cost and bandwidth.

[0014] The external port of the present invention can extend the frequency range to lower frequencies (down to DC components) by using additional metal pins.

[0015] Accordingly, a first aspect of the present invention relates to an external port for bidirectional transmission of radio frequency (RF) signals in an integrated circuit (IC) package, the IC package including a case having an access wall and an IC chip disposed on a first substrate housed within the case, the external port comprising a dielectric waveguide structure embeddable in the access wall of the case, the dielectric waveguide structure configured for bidirectional transmission of RF signals.

[0016] In one example, the dielectric waveguide structure functions as an ultra-wideband dielectric IC port and is configured to be connectable to a second IC chip, an external waveguide, a dielectric structure, or an antenna.

[0017] In one example, the dielectric waveguide structure provides a high-pass characteristic interconnect that operates over a wide frequency range, from a low cutoff frequency f0 in the microwave or millimeter wave band to a high cutoff frequency of at least 100 GHz or higher.

[0018] In another embodiment, the external port of the present invention further includes a second substrate connected to the dielectric waveguide structure and connectable to the first substrate, and a first metallization portion on the second substrate connectable to the IC chip, The second substrate includes an RF substrate using quartz, laminate, ceramic, or silicon.

[0019] In a preferred example, the dielectric waveguide structure has a tapered end.

[0020] In one example, the external port of the present invention includes a second metallization portion electrically connected to the first metallization portion, wherein both the first metallization portion and the second metallization portion are metallic waveguide structures that provide a low-pass characteristic interconnection, ranging from DC components to a high cutoff frequency f in the millimeter-wave band. CH The external port of the present invention may further include a first electrical interconnection portion configured to electrically connect the first metallization portion and the second metallization portion.

[0021] In one example, the first electrical interconnect comprises an epoxy.

[0022] In one example, the external port of the present invention further comprises two metal pins embeddable in the access wall and connectable to the IC chip by a metal connection means, which may include wire bonding, epoxy, or ribbon bonding.

[0023] In one example, the external port of the present invention further comprises a second electrical interconnect configured to electrically connect the two metal pins to the second metallization.

[0024] Another aspect of the present invention relates to an IC package for transmitting or receiving RF signals, the IC package comprising an external port according to the first aspect of the present invention.

[0025] In one example, the first substrate of the IC package includes a quartz, laminate, ceramic, or silicon based RF substrate.

[0026] In one example, the access walls of the IC package have dovetail or V-groove shapes that act as mechanical aids for aligning external waveguides, antennas, connectors, or other components or devices that are connected to ports of the IC package. [Brief explanation of the drawings]

[0027] For a better understanding of the above description and for the purpose of example only, some non-limiting drawings are included which show, in a schematic manner, practical embodiments.

[0028] [Figure 1] 1 shows an external port according to a first example of the present invention. [Figure 2] 1 shows an external port according to a first example of the present invention. [Figure 3] 10 shows an external port according to a second example of the present invention, the external port comprising a dielectric waveguide structure with a tapered end. [Figure 4] 10 shows an external port according to a second example of the present invention, the external port comprising a dielectric waveguide structure with a tapered end. [Figure 5] 10 shows an external port according to a third example of the present invention, the external port comprising a metal pin and a metallization portion. [Figure 6]10 shows an external port according to a fourth embodiment of the present invention, the external port having two metallization portions. [Figure 7] 10 shows an external port according to a fourth embodiment of the present invention, the external port having two metallization portions. [Figure 8] 10 shows an external port according to a fifth example of the present invention, the external port comprising metal pins and electrical connections. [Figure 9] 1 shows an example of an IC package with mechanical access wall support. [Figure 10] 1 shows an example of an IC package with mechanical access wall support. DETAILED DESCRIPTION OF THE INVENTION

[0029] 1 shows a first example of an external port (100) for bidirectional transmission of radio frequency (RF) signals for an integrated circuit (IC) package. The IC package (1000) includes a case (1010) with an access wall (1020). The external port (100) includes a dielectric waveguide structure (IC DRW 1) embedded in the access wall (1020) of the case (1010). The dielectric waveguide structure (IC DRW 1) is configured to transmit RF signals bidirectionally.

[0030] In this particular example, an 8-pin TDFN plastic IC package (1000) is shown. Access walls (1020) within the case (1010) are reserved for a dielectric waveguide structure (IC DRW 1). The metal pins of the case (1010) can be used for conventional electrical connections.

[0031] A dielectric rod waveguide having a dielectric constant similar to or equal to that of the dielectric waveguide structure (IC DRW 1) may be attached to the access wall (1020). The dielectric waveguide structure (IC DRW 1) functions as an ultra-wideband dielectric IC port and can be used to connect the IC package (1000) to another ultra-wideband IC port, an external waveguide (e.g., a rectangular waveguide), a dielectric structure (e.g., a resonator), or an antenna.

[0032] Figure 2 shows the interior of the example shown in Figure 1. The IC package (1000) includes an IC chip (1030) mounted on a substrate (1040) housed in a case (1010). The IC package (1000) is a composite including a substrate (1040) with a low or medium dielectric constant, such as FR-4, Rogers®, or Duroid®. The first substrate (1040) includes an RF substrate made of quartz, laminate, ceramic, or silicon.

[0033] The dielectric waveguide structure (IC DRW 1) connects the IC chip (1030) to the access wall (1020) for bidirectional transmission of RF signals, providing a high-pass characteristic interconnection operating in a high frequency band from a low cutoff frequency f0 in the microwave or millimeter wave band to a high cutoff frequency of at least 100 GHz or more.

[0034] 3 shows the inside of a second example external port (100) according to the present invention, which includes a dielectric waveguide structure (IC DRW 1), the tapered tip of which is placed on top of an IC chip (1030).

[0035] In the example shown in FIG. 3, the external port (100) further comprises a second substrate (110) connected to the dielectric waveguide structure (IC DRW 1) and to a first substrate (1040) of the IC chip (1030), and a first metallization portion (120A) connected to the IC chip (1030) and disposed on the substrate (1040). The second substrate (110) includes an RF substrate made of quartz, laminate, ceramic, or silicon. The first metallization portion (120A) is a (tapered) metal waveguide structure that provides a low-pass characteristic interconnect, ranging from DC components to a high cutoff frequency f in the millimeter-wave band. CH The waveguide structure can be made of metal and operates in the low frequency range up to 1000 MHz.

[0036] Figure 4 shows the example of Figure 3 in more detail. The dielectric waveguide structure (IC DRW 1) transmits RF signals with low loss and no transmission nulls over a wide bandwidth in the absence of inter-modal interference. This requires that the majority of the signal power be coupled into the fundamental waveguide mode at all frequencies. The main bandwidth limitation is due to the presence of higher-order modes. Because higher-order modes can be excited by misalignment between elements, the maximum frequency is determined by manufacturing capabilities. To extend the high-frequency limit, a first metallization portion (120A) (e.g., a tapered metal waveguide structure) can be printed on the IC chip (1030).

[0037] The horizontal dimension of the cross section of the dielectric waveguide structure (IC DRW 1) is its width and its vertical dimension is its thickness, both of which are related to the low frequency limit of the external port (100).

[0038] 5 shows a third example of an external port according to the present invention, including two metal pins (150) and a first metallization portion (120A) that provides DC extension. In the third example, the external port (100) further comprises two metal pins (150) that can be embedded in the access wall (1020) and can be connected to the IC chip (1030) by a metallic connection means (150A) that connects them to the first metallization portion (120A). In this particular case, the metallic connection means (150A) comprises wire bonding. In other examples, the metallic connection means (150A) can be constructed of epoxy or ribbon bonding.

[0039] 6 shows an external port (100) according to a fourth example of the present invention, which includes two metallization portions. In particular, in the fourth example, the external port (100) includes a first metallization portion (120A) and a second metallization portion (120B) electrically connected to the first metallization portion (120A). Both the first metallization portion (120A) and the second metallization portion (120B) are metallic waveguide structures that provide low-pass characteristic interconnections, and have a high cutoff frequency f in the DC to millimeter-wave band. CH It can be constructed from (tapered) metallic waveguide structures operating in the low frequency range down to

[0040] In this example, to achieve a bandwidth of 65 GHz to 300 GHz, the length of the second metallization portion (120B) is set to 14.5 mm. To avoid this increase in length, the second metallization portion (120B) can be extended outside the IC chip (1030).

[0041] The external port (100) according to the fourth example further comprises a first electrical interconnect (140A) configured to electrically connect the first metallization (120A) and the second metallization (120B). The first metallization (120A) is connected to the second metallization (120B) by the first electrical interconnect (140A), which may include a conductive epoxy or the like. The quality of this electrical contact (maximum frequency f m (with respect to f) depends linearly on the conduction cutoff point. The conduction cutoff point close to the external port (100) is close to f m When the frequency is f m If the signal exceeds 100 MHz, the signal is coupled into the dielectric waveguide structure (IC DRW 1) before the transition between the IC chip (1030) and the second metallization (120B).

[0042] Figure 7 shows a detailed view of Figure 6. In this figure, the first electrical interconnect (140A) configured to electrically connect the first metallization (120A) and the second metallization (120B) is shown in detail, along with the dielectric waveguide structure (IC DRW 1) and the second substrate (110) connected to the first substrate (1040).

[0043] 8 shows an external port (100) according to a fifth embodiment of the present invention, comprising two metal pins (150) and an electrical interconnect. The external port (100) comprises two metal pins (150) that can be embedded in an access wall (1020) and connectable to an IC chip (1030) by metallic connection means (150A), and a second electrical interconnect (140B) configured to electrically connect the two metal pins (150) to a second metallization (120B) that provides DC extension. The DC extension is implemented internally by connecting the two metal pins (150) to the second metallization (120B) (e.g., a tapered metal waveguide structure).

[0044] As mentioned above, by adding two metal pins (150) to the external port (100), it is possible to extend the bandwidth to the low frequency side. Therefore, the external port (100) comprises a dielectric waveguide structure (IC DRW 1) and two metal pins (150). In this example, the external port (100) is a hybrid type because it includes a dielectric waveguide structure (IC DRW 1) and two metal pins (150). At low frequencies, it functions as a balanced bifilar line. At frequencies above f0, the signal is transmitted as a HE 11 is coupled to the mode.

[0045] 9 and 10 show examples of IC packages 1000 with mechanical support features on the access walls 1020. In the previous examples, the access walls 1020 were assumed to be planar. Mechanical support features can also be added to the access walls 1020 to enhance alignment between the external waveguide and the external port 100. In FIGS. 9 and 10, the access walls 1020 can be formed into dovetail and V-groove shapes, respectively, to accommodate an external waveguide (not part of the present invention) with a cover made of any material with a lower dielectric constant than the DRW material (e.g., plastic or epoxy) that conforms to the IC port shape. This is because molding can be easier if molding is not performed directly on the DRW. [Explanation of symbols]

[0046] 100...External Port 1000 IC package 1010···Case 1020···Access Wall 1030···IC chip 1040: First substrate 110... Second substrate 120A...First metallization section 120B Second metallization section 140A First Electrical Interconnect 140B... Second electrical interconnection 150···Metal pin 150A···Metallic connection means IC DRW 1···Dielectric waveguide structure

Claims

1. 1. An external port (100) for bidirectional transmission of radio frequency (RF) signals in an integrated circuit (IC) package, the IC package (1000) including a case (1010) having an access wall (1020) and an IC chip (1030) disposed on a first substrate (1040) housed within the case (1010), the external port (100) comprising a dielectric waveguide structure (IC DRW 1) embeddable in the access wall (1020) of the case, the dielectric waveguide structure (IC DRW 1) configured for bidirectional transmission of RF signals.

2. 2. The external port (100) of claim 1, wherein the dielectric waveguide structure (IC DRW 1) functions as an ultra-wideband dielectric IC port and is configured to be connectable to a second IC chip, an external waveguide, a dielectric structure, or an antenna.

3. 3. The external port (100) according to claim 1 or 2, wherein the dielectric waveguide structure (IC DRW 1) has a low cutoff frequency f in the microwave band or the millimeter wave band. ０ and an external port (100) that provides a high-pass characteristic interconnection operating in a high frequency band from a high cutoff frequency of at least 100 GHz or more.

4. The external port (100) according to any one of claims 1 to 3, further comprising: a second substrate (110) connected to said dielectric waveguide structure (IC DRW 1) and connectable to said first substrate (1040); a first metallization portion (120A) connectable to the IC chip (1030) and provided on the substrate (1040); An external port (100) comprising:

5. 5. The external port (100) of claim 4, wherein the second substrate (110) comprises an RF substrate made of quartz, laminate, ceramic, or silicon.

6. 6. The external port (100) of claim 5, wherein the dielectric waveguide structure (IC DRW 1) has a tapered end.

7. The external port (100) according to any one of claims 4 to 6, further comprising a second metallization portion (120B) electrically connected to the first metallization portion (120A) and mechanically connected to the dielectric waveguide structure (IC DRW 1).

8. 8. The external port (100) of claim 7, wherein the first metallization portion (120A) and the second metallization portion (120B) are both metal waveguide structures that provide low-pass characteristic interconnects, and have a high cutoff frequency f in the DC to millimeter-wave band. ＣＨ 1. An external port (100) characterized by being a metallic waveguide structure operating in the low frequency range up to 100 MHz.

9. 9. The external port (100) of claim 8, further comprising a first electrical interconnection portion (140A) configured to electrically connect the first metallization portion (120A) and the second metallization portion (120B).

10. 10. The external port (100) of claim 9, wherein the first electrical interconnect (140A) comprises a conductive epoxy, a wire bond, or a ribbon bond.

11. The external port (100) according to any one of claims 1 to 10, further comprising two metal pins (150) that can be embedded in the access wall (1020) and can be connected to the IC chip (1030) by a metal connection means (150A).

12. 12. The external port (100) of claim 11, wherein the metallic connection means (150A) comprises wire bonding, epoxy, or ribbon bonding.

13. 13. The external port (100) of claim 11 or 12, further comprising a second electrical interconnection portion (140B) configured to electrically connect the two metal pins (150) to the second metallization portion (120B).

14. An integrated circuit (IC) package (1000) for transmitting or receiving RF signals, characterized in that the IC package (1000) comprises an external port according to any one of claims 1 to 13.

15. 15. The IC package of claim 14, wherein the first substrate (1040) comprises a quartz, laminate, ceramic, or silicon based RF substrate.

16. 16. The IC package (1000) according to claim 14 or 15, wherein the access wall (1020) has a dovetail or V-groove shape.

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