JP5361023B2 - Method for measuring high-frequency signal transmission characteristics of wiring board and wiring board used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring method of a high-frequency signal transmission characteristic of a wiring board capable of measuring a transmission characteristic of a signal in a transmission line for connecting a pad having a narrow pitch to a pad having a wide pitch on the wiring board, excellently even in a frequency band of a high frequency exceeding 10 GHz, and to provide the wiring board used therefor. <P>SOLUTION: A probe connection pad 5S for a signal and a probe connection pad 5S for grounding which are connected to a pad 4S for a signal formed with a wide pitch and a pad 4G for grounding are provided on the wiring board 10 so that the pitch is narrowed, and a probe 8 having a contact terminal 9S for a signal and a contact terminal 9G for grounding whose tip parts are arranged with a narrow pitch are brought into contact with an external connection pad for a signal and an external connection pad for grounding, to thereby perform measurement, by bringing the tip part of the contact terminal 9S for the signal into contact with the probe connection pad 5S for the signal, and by bringing the tip part of the contact terminal 9G for grounding into contact with the probe connection pad 5G for grounding. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to measurement of high-frequency signal transmission characteristics of a wiring board and a wiring board used therefor.

  A wiring board for mounting a semiconductor element may be required to have good signal transmission characteristics in a frequency band of a high frequency exceeding 10 GHz, for example, as the operation of the semiconductor element increases in speed and frequency. In such a case, the wiring board designer considers the dielectric constant and dielectric loss tangent of the insulating material that constitutes the wiring board, the electrical conductivity of the conductor, etc., and the transmission line characteristic impedance and signal transmission Design so that the mode is as constant as possible. However, in reality, complicated factors are entangled, and the signal is rarely propagated as designed, and the probe of the measuring device is applied to both ends of the transmission line to determine whether the signal propagates well through the transmission line on the wiring board. At the same time, a high frequency signal is input from one end of the transmission line, and the reflection loss and transmission loss of the signal are measured.

  As shown in FIGS. 2A and 2B, a conventional method for measuring transmission characteristics of a transmission line in a flip chip BGA type wiring board 20 on which a semiconductor element is mounted by flip chip connection will be described. The wiring substrate 20 is made of a ceramic material or a resin material, and is made of an insulating substrate 11 having a mounting portion 11a for mounting a semiconductor element at the center of the upper surface, and made of a highly conductive material such as copper. 11a, and a wiring conductor including a signal line 12S and a ground line 12G that are led to the lower surface of the insulating substrate 11 through the inside of the insulating substrate 11. The signal line 12S and the ground line 12G form a transmission line for transmitting signals in pairs with each other, and a circular signal semiconductor having a diameter of about 70 to 100 μm to which the electrode of the semiconductor element is connected in the mounting portion 11a. A plurality of semiconductor element connection pads including the element connection pad 13S and the grounding semiconductor element connection pad 13G are provided at a pitch of about 100 to 200 μm, and are connected to the wiring conductor of the external electric circuit on the lower surface of the insulating substrate 11. A plurality of external connection pads including a circular signal external connection pad 14S and a ground external connection pad 14G having a diameter of about 400 to 600 μm are provided at a pitch of about 800 to 1200 μm.

  In order to measure the signal transmission characteristic in the transmission line composed of the signal line 12S and the ground line 12G on the wiring board 20, the probes 15 and 17 of the measuring device for measuring the transmission characteristic are connected to the signal semiconductor element. The pad 13S and the ground semiconductor element connection pad 13G are connected to the signal external connection pad 14S and the ground external connection pad 14G, respectively. For example, signals are input from the signal semiconductor element connection pad 13S and the ground semiconductor element connection pad 13G. Then, the amount of the signal returning to the signal semiconductor element connection pad 13S and the ground semiconductor element connection pad 13G or the amount of the signal reaching the signal external connection pad 14S and the ground external connection pad 14G is measured, or vice versa. From external connection pad 14S for ground and external connection pad 14G for grounding To measure the amount of a signal returning to the signal external connection pad 14S and the ground external connection pad 14G and a signal reaching the signal semiconductor element connection pad 13S and the ground semiconductor element connection pad 13G. Thus, a method for obtaining the reflection loss and insertion loss of the transmission line is adopted.

  The probe 15 connected to the signal semiconductor element connection pad 13S and the ground semiconductor element connection pad 13G has a signal contact terminal 16S connected to the signal semiconductor element connection pad 13S disposed at the center. The ground contact terminals 16G connected to the ground semiconductor element connection pads 13G are arranged on both sides thereof. The signal contact terminal 16S and the ground contact terminal 16G in the probe 15 have pitches of 100 to 200 μm corresponding to the arrangement pitch of the semiconductor element connection pads 13S and 13G, and the characteristic impedance at the signal contact terminal 16S. For example, it is arranged to be 50Ω, and the tip of the signal contact terminal 16S is brought into contact with the signal semiconductor element connection pad 13S, and the tip of the ground contact terminal 16G is brought into contact with the ground semiconductor element connection pad 13G. As a result, each is connected to the signal semiconductor element connection pad 13S and the ground semiconductor element connection pad 13G.

  On the other hand, the probe 17 connected to the signal external connection pad 14S and the ground external connection pad 14G has a signal contact terminal 18S connected to the signal external connection pad 14S at the center, and both sides thereof. Further, a ground contact terminal 18G connected to the ground external connection pad 14G is disposed. In this probe 17, the width of the tip of the ground contact terminal 18G on both sides is wider than the signal contact terminal 18S in the center, and the signal contact terminal 18S and the ground contact terminal 18G are in the center. The tip of the contact terminal 18S and the outer tip of the ground contact terminal 18G on both sides have a pitch of 800 to 1200 μm corresponding to the arrangement pitch of the external connection pads 14S and 14G, and the characteristic impedance in the signal contact terminal 18S is For example, the signal contact terminal 18S is brought into contact with the signal external connection pad 14S and the ground contact terminal 18G is brought into contact with the ground external connection pad 14G so that each signal external terminal is connected to the signal external connection pad 14G. The connection pad 14S is connected to the grounding external connection pad 14G.

  However, in this conventional method, in the probe 15 connected to the semiconductor element connection pads 13S and 13G, the pitch of the tips contacting the semiconductor element connection pads 13S and 13G corresponds to the pitch of the semiconductor element connection pads 13S and 13G. In the probe 17 connected to the external connection pads 14S and 14G, the pitch of the tips contacting the external connection pads 14S and 14G corresponds to the pitch of the external connection pads 14S and 14G. A wide pitch of 800 to 1200 μm is obtained. As described above, when the pitch of the tip portions of the probe 17 contacting the external connection pads 14S and 14G is a wide pitch of 800 to 1200 μm, the signal transmission characteristics in the frequency band of 10 GHz or less can be sufficiently measured. However, it was difficult to measure well in a frequency band exceeding 10 GHz.

JP 2001-264384 A

  It is an object of the present invention to be able to satisfactorily measure signal transmission characteristics in a transmission line connecting a pad with a narrow pitch and a pad with a wide pitch on a wiring board even in a high frequency band exceeding 10 GHz. An object of the present invention is to provide a method for measuring high-frequency signal transmission characteristics of a wiring board and a wiring board used therefor.

  The method for measuring high-frequency signal transmission characteristics of a wiring board according to the present invention includes a first signal pad and a first grounding pad provided at a first pitch, and a second pitch wider than the first pitch. A second signal pad and a second grounding pad provided; a signal line connecting the first signal pad and the second signal pad; and the first grounding pad; The first signal pad, the first ground pad, the second signal pad, and the second ground of the wiring board having a ground line connecting between the second ground pad and the second ground pad. A method of measuring a high-frequency signal transmission characteristic of a wiring board for measuring a high-frequency signal transmission characteristic between the circuit board and a probe of a measuring device between the two pads, wherein the second signal is applied to a surface of the wiring board. Connected to the pad A third pitch in which the pitch between the signal probe connection pad and the ground probe connection pad is smaller than the second pitch. A first probe having a first signal contact terminal and a first ground contact terminal, the tip of which is arranged at the first pitch, and the first signal contact terminal. The first signal pad and the first signal pad and the first ground pad by contacting the first ground pad and the first ground pad. A second probe having a second signal contact terminal and a second ground contact terminal which are connected to the first ground pad and whose tips are arranged at the third pitch; By bringing the tip of the second signal contact terminal into contact with the signal probe connection pad and bringing the tip of the second ground contact terminal into contact with the ground probe connection pad, the second The signal pad and the second grounding pad are connected for measurement.

  The wiring board of the present invention includes a first signal pad and a first grounding pad provided at a first pitch, and a second pitch provided at a second pitch wider than the first pitch. A signal pad and a second grounding pad; a signal line connecting the first signal pad and the second signal pad; and the first grounding pad and the second grounding pad. A wiring board having a ground line connecting between the pads and a signal probe connection pad connected to the second signal pad and a ground probe connection connected to the second ground pad The pad is provided so that a pitch between the signal probe connection pad and the ground probe connection pad is narrowed to a third pitch which is narrower than the second pitch.

  According to the method for measuring a high-frequency signal transmission characteristic of the wiring board according to the present invention, the second signal pad and the second grounding pad formed at a second pitch wider than the first pitch are applied to the second grounding pad. The signal probe connection pad connected to the signal pad and the ground probe connection pad connected to the second ground pad are arranged such that the pitch between the signal probe connection pad and the ground probe connection pad is the first pitch. A second board having a second signal contact terminal and a second ground contact terminal provided on the wiring board so as to be narrowed to a third pitch narrower than the second pitch, and having a tip portion arranged at the third pitch. The probe is connected to the tip of the second signal contact terminal and the signal probe connection pad, and the tip of the second ground contact terminal is connected to the ground probe. The second signal pad and the second grounding pad are brought into contact with each other, so that even if the second pitch is as wide as 800 to 1200 μm, the third signal pad and the second grounding pad are connected. Measurement is performed by connecting the measuring device, the second signal pad, and the second grounding pad using a probe having a narrow pitch at the tip of the contact terminal by setting the pitch to be narrow, for example, 100 to 200 μm. Therefore, it is possible to satisfactorily measure the high-frequency signal transmission characteristics of the wiring board even in a frequency band exceeding 10 GHz.

  Further, according to the wiring board of the present invention, the second signal pad and the second ground pad formed at the second pitch wider than the first pitch are connected to the second signal pad. The signal probe connection pad and the ground probe connection pad connected to the second ground pad are arranged so that the pitch between the signal probe connection pad and the ground probe connection pad is narrower than the second pitch. Since the third pitch is narrowed to the third pitch, even if the second pitch is as wide as 800 to 1200 μm, the third pitch is set as narrow as 100 to 200 μm, for example. Since it is possible to measure by connecting the second signal pad and the second grounding pad using a probe having a narrow pitch at the tip of the contact terminal, Even in a frequency band exceeding 10 GHz, the high-frequency signal transmission characteristics of the wiring board can be satisfactorily measured.

(A) is a simplified sectional view for explaining an example of an embodiment of a high-frequency signal transmission characteristic of a wiring board of the present invention and a wiring board used therefor, and (b) is a measurement shown in (a). It is a simplified bottom view for demonstrating a method and a wiring board. (A) is a simplified cross-sectional view for explaining a conventional method for measuring a high-frequency signal transmission characteristic of a wiring board, and (b) is a simplified bottom view for explaining the measuring method and the wiring board shown in (a). FIG.

  Next, a method for measuring high-frequency signal transmission characteristics of a wiring board according to the present invention and a wiring board used therefor will be described with reference to FIGS. 1 (a) and 1 (b). As shown in FIG. 1 (a), the wiring substrate 10 of the present invention used in the method for measuring the high-frequency signal transmission characteristics of the wiring substrate of the present invention includes ceramic materials such as alumina, aluminum nitride, mullite, glass ceramics, and epoxy. An insulating substrate 1 made of a resin material containing a thermosetting resin such as a resin, a bismaleimide triazine resin, or an allyl-modified polyphenylene ether resin, and having a mounting portion 1a for mounting a semiconductor element at the center of the upper surface; and tungsten or molybdenum And a wiring conductor including a signal line 2 </ b> S and a ground line 2 </ b> G led out from the mounting portion 1 a of the insulating substrate 1 to the lower surface of the insulating substrate 1 through the inside of the insulating substrate 1. The signal line 2S and the ground line 2G form a transmission line for transmitting signals in pairs with each other, and a circular signal semiconductor having a diameter of about 70 to 100 μm to which the electrode of the semiconductor element is connected in the mounting portion 1a. A plurality of semiconductor element connection pads including the element connection pads 3S and the grounding semiconductor element connection pads 3G have, for example, a lattice shape and a pitch of about 100 to 200 μm, and wiring of an external electric circuit on the lower surface of the insulating substrate 1 A plurality of external connection pads including a circular signal external connection pad 4S having a diameter of about 400 to 600 μm and a ground external connection pad 4G connected to the conductor are provided, for example, in a lattice shape and at a pitch of about 800 to 1200 μm. Yes.

  Furthermore, in the present invention, a signal probe connection pad 5S connected to the signal external connection pad 4S and a ground probe connection pad 5G connected to the ground external connection pad 4G are provided on the lower surface of the wiring board 10. . The signal probe connection pad 5S and the ground probe connection pad 5G are made of the same material as the signal external connection pad 4S and the ground external connection pad 4G. Usually, the signal external connection pads 4S correspond to each other. Alternatively, it is integrally formed with the grounding external connection pad 4G. The signal probe connection pad 5S and the ground probe connection pad 5G are formed so that the pitch is narrower at one end than the pitch of the signal external connection pad 4S and the ground external connection pad 4G. The pitch at the narrowed portion is 100 to 200 μm, which is the same as the pitch of the semiconductor element connection pads 3S and 3G.

  In order to measure the high-frequency signal transmission characteristic in the transmission line composed of the signal line 2S and the ground line 2G on the wiring board 10, the probes 6 and 8 of the measuring device for measuring the transmission characteristic are connected to the signal semiconductor element. The pad 3S and the ground semiconductor element connection pad 3G are connected to the signal probe connection pad 5S and the ground probe connection pad 5G, respectively. For example, signals are input from the signal semiconductor element connection pad 3S and the ground semiconductor element connection pad 3G. Then, the amount of the signal returning to the signal semiconductor element connection pad 3S and the ground semiconductor element connection pad 3G or the amount of the signal reaching the signal probe connection pad 5S and the ground probe connection pad 5G is measured, or vice versa. Signals from the probe connection pad 5S and the ground probe connection pad 5G By measuring the amount of the signal returning to the signal probe connection pad 5S and the ground probe connection pad 5G and the amount of the signal reaching the signal semiconductor element connection pad 3S and the ground semiconductor element connection pad 3G. The method of obtaining the reflection loss and insertion loss of the transmission line is employed.

  The probe 6 connected to the signal semiconductor element connection pad 3S and the ground semiconductor element connection pad 3G has a signal contact terminal 7S connected to the signal semiconductor element connection pad 3S at the center. The ground contact terminals 7G connected to the ground semiconductor element connection pads 3G are arranged on both sides thereof. The signal contact terminal 7S and the ground contact terminal 7G in the probe 6 have pitches of 100 to 200 μm corresponding to the arrangement pitch of the semiconductor element connection pads 3S and 3G, and the characteristic impedance at the signal contact terminal 7S. For example, the tip of the signal contact terminal 7S is brought into contact with the signal semiconductor element connection pad 3S and the tip of the ground contact terminal 7G is brought into contact with the ground semiconductor element connection pad 3G. As a result, each is connected to the signal semiconductor element connection pad 3S and the ground semiconductor element connection pad 3G.

  On the other hand, the probe 8 connected to the signal probe connection pad 5S and the ground probe connection pad 5G has a signal contact terminal 9S connected to the signal probe connection pad 5S at the center, and both sides thereof. The ground contact terminals 9G connected to the ground probe connection pads 5G are arranged. The signal contact terminal 9S and the ground contact terminal 9G in the probe 8 have pitches of 100 to 200 μm corresponding to the arrangement pitch of the probe connection pads 5S and 5G, and the characteristic impedance of the signal contact terminal 9S is, for example, The tip of the signal contact terminal 9S is brought into contact with the signal probe connection pad 5S and the tip of the ground contact terminal 9G is brought into contact with the ground probe connection pad 5G. Each is connected to the signal probe connection pad 5S and the ground probe connection pad 5G.

  At this time, according to the method for measuring the high-frequency signal transmission characteristic of the wiring board of the present invention, the signal external connection pad 4S and the ground external connection pad 4G formed with a wide pitch of 800 to 1200 μm are connected to the signal external connection pad. The signal probe connection pad 5S connected to 4S and the ground probe connection pad 5G connected to the ground external connection pad 4G have the pitch between the signal probe connection pad 5S and the ground probe connection pad 5G as the external connection pad. A probe 8 having a signal contact terminal 9S and a ground contact terminal 9G provided on the wiring board 10 so as to be narrowed to a pitch of 100 to 200 μm, which is narrower than the pitch of 4S and 4G, and having tip portions arranged at a pitch of 150 to 200 μm. Is brought into contact with the tip of the signal contact terminal 9S and the signal probe connection pad 5S. Since both are connected to the signal external connection pad 4S and the ground external connection pad 4G by bringing the tip of the ground contact terminal 9G into contact with the ground probe connection pad 5G, the pitches of the external connection pads 4S and 4G are the same. The contact terminal between the measuring device and the signal external connection pad 4S and the ground external connection pad 4G is reduced by narrowing the pitch of the probe connection pads 5S and 5G to 100 to 200 μm. Since it becomes possible to perform measurement by connecting with the narrow probe 8 having a pitch of 9S, 9G of 100 to 200 μm, the high frequency signal transmission characteristic of the wiring board 10 is excellent even in a frequency band exceeding 10 GHz. Can be measured.

  Further, according to the wiring board 10 of the present invention, the signal probe connected to the signal external connection pad 4S is connected to the signal external connection pad 4S and the ground external connection pad 4G formed at a wide pitch of 800 to 1200 μm. The grounding probe connection pad 5G connected to the connection pad 5S and the grounding external connection pad 4G has a narrower pitch between the signal probe connection pad 5S and the grounding probe connection pad 5G than the pitch of the external connection pads 4S and 4G. Since the wiring board 10 is provided so as to be narrowed to a pitch of ˜200 μm, even if the pitch of the external connection pads 4S, 4G is as wide as 800-1200 μm, the pitch of the probe connection pads 5S, 5G is set to 100— By narrowing to 200 μm, measuring device, signal external connection pad 4S and grounding outside Measurement can be performed by connecting the connection pad 4G with a narrow probe 8 having a pitch of 100 to 200 μm at the tips of the contact terminals 9S and 9G, so that the wiring board 10 can be used even in a frequency band exceeding 10 GHz. High frequency signal transmission characteristics can be measured satisfactorily. Incidentally, the inventor has an analysis model corresponding to the present invention in which a probe having a pitch of 200 μm is connected to both ends of a transmission line composed of a signal line whose characteristic impedance is matched to 50Ω and a ground line on both sides thereof, According to the results of analysis using an electromagnetic simulator, an analysis model corresponding to the prior art in which a probe having a pitch of 200 μm is connected to one end of a transmission line and a probe having a pitch of 1000 μm is connected to the other end corresponds to the present invention. In this model, as compared with the model corresponding to the prior art, the radiation loss at 20 GHz between the probes at both ends of the transmission line is improved by about 5 dB, and the insertion loss is improved by about 0.1 dB.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the wiring board 10 can be changed. Although the case where the transmission characteristics between the semiconductor element connection pads 3S, 3G provided on the upper surface and the external connection pads 4S, 4G provided on the lower surface of the wiring substrate 10 are measured has been described, it is provided on the upper surface side of the wiring substrate. The present invention may be applied when measuring transmission characteristics between pads provided between pads or pads provided on the lower surface side of the wiring board.

1 Insulating Substrate 2S Signal Line 2G Ground Line 3S Signal Semiconductor Device Connection Pad (First Signal Pad)
3G grounding semiconductor element connection pad (first grounding pad)
4S signal external connection pad (second signal pad)
External connection pad for 4G grounding (second grounding pad)
5S Signal probe connection pad 5G Ground probe connection pad 6 Probe (first probe)
7S Signal contact terminal (first signal contact terminal)
7G Grounding contact terminal (first grounding contact terminal)
8 Probe (second probe)
9S Signal contact terminal (second signal contact terminal)
9G contact terminal for grounding (second contact terminal for grounding)
10 Wiring board

Claims (6)

  A first signal pad and a first ground pad provided at a first pitch; a second signal pad and a second ground pad provided at a second pitch wider than the first pitch; A pad, a signal line connecting between the first signal pad and the second signal pad, and a ground line connecting between the first ground pad and the second ground pad A high-frequency signal transmission characteristic between the first signal pad and the first ground pad and the second signal pad and the second ground pad of the wiring board having A method of measuring a high-frequency signal transmission characteristic of a wiring board that is measured by connecting a probe of a measuring device, the signal probe connection pad connected to the second signal pad on the surface of the wiring board, and the second Grounding pads The connected grounding probe connection pad is provided so that the pitch between the signal probe connection pad and the grounding probe connection pad is narrowed to a third pitch that is narrower than the second pitch, and the tip portion is the first A first probe having a first signal contact terminal and a first ground contact terminal arranged at a pitch of the first signal contact terminal and the first signal pad. The front end portion of the first ground contact terminal and the first ground pad are brought into contact with each other to connect to the first signal pad and the first ground pad, and the front end portion A second probe having a second signal contact terminal and a second ground contact terminal arranged at the third pitch, the tip of the second signal contact terminal and the signal probe And connecting to the second signal pad and the second grounding pad by bringing the tip of the second grounding contact terminal into contact with the grounding probe connection pad. And measuring the high-frequency signal transmission characteristics of the wiring board.   2. The method for measuring high-frequency signal transmission characteristics of a wiring board according to claim 1, wherein the first pitch is 100 to 200 μm and the second pitch is 800 to 1200 μm.   The method for measuring high-frequency signal transmission characteristics of a wiring board according to claim 1, wherein the third pitch is 100 to 200 μm.   A first signal pad and a first ground pad provided at a first pitch; a second signal pad and a second ground pad provided at a second pitch wider than the first pitch; A pad, a signal line connecting between the first signal pad and the second signal pad, and a ground line connecting between the first ground pad and the second ground pad A signal probe connection pad connected to the second signal pad and a ground probe connection pad connected to the second ground pad, and the signal probe connection pad. A wiring board provided so that a pitch with the ground probe connection pad is narrowed to a third pitch which is narrower than the second pitch.   The wiring board according to claim 4, wherein the first pitch is 100 to 200 μm, and the second pitch is 800 to 1200 μm.   6. The wiring board according to claim 4, wherein the third pitch is 100 to 200 [mu] m.

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