Abstract:
The present invention discloses a semiconductor chip probe for measuring conducted electromagnetic emission (EME) of a bare die and a conducted EME measurement apparatus with the semiconductor chip probe. The semiconductor chip probe comprises a substrate, a dielectric layer, an impedance unit, a measuring unit and a connection unit. The measurement apparatus comprises a semiconductor chip probe, a high frequency probe, a signal cable and a test receiver. The integrated passive component network designed and embedded inside the semiconductor chip probe forms the 1Ω or 150Ω impedance network. And the semiconductor chip probe is able to directly couple the EME conducted current or voltage from the test pin of the flipped chip under test to the test receiver for measurement.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a semiconductor chip probe and a measurement apparatus with the semiconductor chip probe, and more particularly, to a semiconductor chip probe having a passive component network built therein and measuring a high-frequency electromagnetic emission (EME) conducted current or voltage of a flipped chip through direct coupling and a measurement apparatus with the semiconductor chip probe. 
         [0003]    2. Description of Related Art 
         [0004]    Problems arising from electromagnetic compatibility (EMC) have become increasingly important in detection of various semiconductor and electronic apparatuses. In the past, processing operations are mostly carried out at the hierarchy of terminal products or system modules or circuit boards for the problems and design modifications about the EMC. However, because currently the requirements on the EMC become increasingly higher and there are increasingly more high-frequency electronic products, it has become necessary to evaluate the problems about the EMC effect at the IC bare-die level of semiconductor chips. 
         [0005]    International Electrotechnical Commission (IEC) has issued a series of standards for measurement of the EMC of integrated circuits (ICs), among which there is a series of measurement methods related to electromagnetic emission (EME): the standard IEC-61967. According to different propagation and emission paths of electromagnetic waves, the EME measurement methods may further be categorized into conduction methods and radiation methods, among which the 1 ohm (Ω)/150Ω direct coupling measurement method belongs to the conduction EME measurement methods. 
         [0006]    In 1Ω measurement, an interference current emission at a ground pin is measured through direct coupling, and the magnitude of the electromagnetic interference emission is evaluated through a radio-frequency (RF) current collected at an IC ground point. In 150Ω measurement, an interference voltage emission at an input/output (I/O) end or a power supply port is measured through direct coupling. In the 1Ω/150Ω direct coupling measurement method, testing points are all connected to a test receiver of 50Ω through an impedance matching component. A user must design by himself a probe having an impedance matching network of 1Ω or 150Ω for measurement, and the probe is then connected to the test receiver through an output impedance of 50Ω. 
         [0007]    For all the measurement methods currently available, test of a pin is performed on a packaged IC on a printed circuit board (PCB), and the test result is provided as a product report or to the IC designer for evaluation of the EMC problems. However, due to the effect generated from the package is included in the characteristics of the packaged IC and the size of the probe used will generate a parasitic effect within the measurement frequency range 1 GHz of the standard measurement specifications, the accuracy of the measurement result is always degraded. The higher the operation frequency of the IC under test is, the more significant the parasitic effect will be and the lower the accuracy of the measurement result will be. 
         [0008]    On the other hand, RF probes currently used can only transfer signals and do not allow an impedance matching component to be disposed therein, functions are limited in measuring the conducted EME. 
         [0009]    Accordingly, an urgent need exists in the art to provide bare-die level conducted EME measurement probe and apparatus, which feature high reliability, high stability, a significantly reduced size, a significantly decreased cost and a built-in impedance matching component, to achieve a measurement system capable of testing a bare die. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention discloses a semiconductor chip probe and a conducted EME (electromagnetic emission) measurement apparatus with the semiconductor chip probe. The semiconductor chip probe comprises a substrate, a dielectric layer, an impedance unit, a measuring unit and a connection unit. The measurement apparatus comprises a semiconductor chip probe, a RF probe, a signal cable and a test receiver. The passive components designed and embedded inside the semiconductor chip forms the 1Ω or 150Ω impedance network as a semiconductor chip probe. And the semiconductor chip probe is able to directly couple the EME conducted current or voltage from the test pin of the flipped chip under test to test receiver for measurement. 
         [0011]    To achieve these and other effects, the present invention provides a semiconductor chip probe for measuring conducted electromagnetic emission (EME) of a bare die, the semiconductor chip probe comprises: a substrate; a dielectric layer, being formed on and covering a surface of the substrate; an impedance unit, being accommodated within the dielectric layer and consisting of a passive component network as well as a first metal wire, a second metal wire and a third metal wire that extend from the passive component network, wherein the third metal wire is electrically grounded; a measuring unit, having a test pad and a plurality of metal pads that expose the dielectric layer, wherein the test pad has a metal ball disposed thereon, the metal ball is electrically connected with a pad under test of a flipped chip and inputs a measurement signal from the pad under test, and the test pad is in signal connection with the first metal wire; and a connection unit, being formed by a signal pad and two ground pads that are disposed at two sides of the signal pad respectively, wherein the signal pad and the two ground pads are not contacted with each other and all expose the dielectric layer, the signal pad is electrically connected with the second metal wire, and the two ground pads are electrically grounded. 
         [0012]    To achieve these and other effects, the present invention further provides a conducted EME measurement apparatus with a semiconductor chip probe, which comprises: a semiconductor chip probe; having: a substrate; a dielectric layer, being formed on and covering a surface of the substrate; an impedance unit, being accommodated within the dielectric layer and consisting of a passive component network as well as a first metal wire, a second metal wire and a third metal wire that extend from the passive component network, wherein the third metal wire is electrically grounded; a measuring unit, having a test pad and a plurality of metal pads that expose the dielectric layer, wherein the test pad has a metal ball disposed thereon, the metal ball is electrically connected with a pad under test of a flipped chip and inputs a measurement signal from the pad under test, and the test pad is in signal connection with the first metal wire; and a connection unit, being formed by a signal pad and two ground pads that are disposed at two sides of the signal pad respectively, wherein the signal pad and the two ground pads are not contacted with each other and all expose the dielectric layer, the signal pad is electrically connected with the second metal wire, and the two ground pads are electrically grounded; a high frequency probe, having three contact pins at one end thereof and an output end at the other end thereof, wherein the three contact pins are electrically connected with the signal pad and the two ground pads of the connection unit respectively and input the measurement signal from the connection unit, and the output end outputs the measurement signal; a signal cable, having an end electrically connected with the output end; and a test receiver, being electrically connected with the other end of the signal cable and configured to input the measurement signal from the signal cable and process or display the measurement signal. 
         [0013]    Through implementation of the present invention, at least the following progressive effects can be achieved: 
         [0014]    I. the chip probe features a simple manufacturing process and a low cost and is disposable; 
         [0015]    II. the chip probe is capable of performing conducted EME measurement of bare-die; 
         [0016]    III. the miniaturized chip probe has a particularly low parasitic effect, and thus has increased measurement accuracy and broadband characteristics; and 
         [0017]    IV. the chip probe has an integrated passive component network built therein, features a good impedance matching characteristic, and can perform 1Ω/150Ω conducted EME measurement through direct coupling. 
         [0018]    The features and advantages of the present invention are detailed hereinafter with reference to the preferred embodiments. The detailed description is intended to enable a person skilled in the art to gain insight into the technical contents disclosed herein and implement the present invention accordingly. In particular, a person skilled in the art can easily understand the objects and advantages of the present invention by referring to the disclosure of the specification, the claims, and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
           [0020]      FIG. 1  is a perspective view of a semiconductor chip probe according to an embodiment of the present invention; 
           [0021]      FIG. 2  is a perspective view of the semiconductor chip probe according to the embodiment of the present invention in which details of a measuring unit are denoted; 
           [0022]      FIG. 3  is a perspective view of the semiconductor chip probe according to the embodiment of the present invention in which details of the measuring unit and a connection unit are denoted; 
           [0023]      FIG. 4  is a perspective view of a measurement apparatus according to an embodiment of the present invention; 
           [0024]      FIG. 5A  is an equivalent circuit diagram of a 150 ohm probe according to an embodiment of the present invention; 
           [0025]      FIG. 5B  is an equivalent circuit diagram of a 1 ohm probe according to an embodiment of the present invention; and 
           [0026]      FIG. 6  is a schematic perspective view of a semiconductor chip probe according to an embodiment of the present invention which is electrically connected with a pad under test of a flipped chip. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    As shown in  FIG. 1  to  FIG. 3  and  FIG. 6 , there is shown a semiconductor chip probe  100  for measuring conducted electromagnetic emission (EME) of a bare die according to an embodiment of the present invention, the semiconductor chip probe  100  comprises a substrate  10 , a dielectric layer  20 , an impedance unit  30 , a measuring unit  40  and a connection unit  50 . Because the semiconductor chip probe  100  is completely produced through a semiconductor process, and is a miniaturized integrated circuit (IC) which has a low production cost, the semiconductor chip probe  100  can be disposable. 
         [0028]    The substrate  10  as shown in  FIG. 1  to  FIG. 3  and  FIG. 6  is used to bear the dielectric layer  20 , the impedance unit  30 , the measuring unit  40  and the connection unit  50  of the semiconductor chip probe  100 . The substrate  10  can be a glass substrate, a silicon substrate or a ceramic substrate. 
         [0029]    As shown in  FIG. 1  to  FIG. 3  and  FIG. 6 , the dielectric layer  20  is formed on and covers a surface of the substrate  10 , and is formed of a single dielectric substance or a composite dielectric substance. The dielectric layer  20  covers and protects the impedance unit  30 , the measuring unit  40  and the connection unit  50 , and exposes a part of the measuring unit  40  and the connection unit  50 . The dielectric layer  20  can be the dielectric substance of a capacitor in the impedance unit  30 . 
         [0030]    As also shown in  FIG. 1  to  FIG. 3  and  FIG. 6 , the impedance unit  30  is accommodated within the dielectric layer  20 . The impedance unit  30  consists of a passive component network  30 ′ as well as a first metal wire  31 , a second metal wire  32  and a third metal wire  33  that extend from the passive component network  30 ′. The first metal wire  31  is electrically connected with the measuring unit  40 , the second metal wire  32  is electrically connected with the connection unit  50 , and the third metal wire  33  is electrically grounded. 
         [0031]    As shown in  FIG. 5A  and  FIG. 5B , there are shown equivalent circuits of an embodiment of the impedance unit  30  and the passive component network  30 ′ thereof. The passive component network  30 ′ as shown is actually a part of the integrated circuit of the semiconductor chip probe  100 ; that is, resistors or capacitors in the passive component network  30 ′ are all built in the integrated circuit of the semiconductor chip probe  100 . 
         [0032]    As shown in  FIG. 5A , there is shown an equivalent circuit of an embodiment of a probe of 150 ohm, with the passive component network  30 ′ consisting of a first resistor  34  and a first capacitor  35  connected in series which are then connected in parallel with a second resistor  36 . The first resistor  34  as shown in  FIG. 5A  may be selected as a resistor of 120 ohm, the first capacitor  35  may be selected as a capacitor of 6.8 nF, and the second resistor  36  may be selected as a resistor of 51 ohm. Thus, the semiconductor chip probe  100  becomes an impedance matching network and has an input impedance of 145±20 ohm. The semiconductor chip probe  100  thus built can perform high-frequency EME conducted voltage measurement on a flipped chip  300 . Vi shown in  FIG. 5A  represents a voltage value of a pad under test  301  of the flipped chip  300 , and Vo represents a voltage value measured and output by the probe of 150 ohm. 
         [0033]    As shown in  FIG. 5B , there is shown an equivalent circuit of an embodiment of a probe of 1 ohm, with the passive component network  30 ′ consisting of a third resistor  37  and a fourth resistor  38  connected in parallel. The third resistor  37  may be selected as a resistor of 49 ohm, and the fourth resistor  38  may be selected as a resistor of 1 ohm. Thus, the semiconductor chip probe  100  becomes an impedance matching network and has an input impedance of 1 ohm. The semiconductor chip probe  100  can perform high-frequency EME conducted current measurement on the flipped chip  300 . 
         [0034]    As shown in  FIG. 1  to  FIG. 3  and  FIG. 6 , the measuring unit  40  has a test pad  41  and a plurality of metal pads  42 , and the test pad  41  and the metal pads  42  expose the dielectric layer  20 . The test pad  41  has a metal ball  43  disposed thereon, and the metal ball  43  is electrically connected with the pad under test  301  of the flipped chip  300  and inputs a measurement signal from the pad under test  301 . The test pad  41  of the measuring unit  40  is electrically connected with the first metal wire  31  of the impedance unit  30 , and outputs the measurement signal to the impedance unit  30 . Because of the impedance is matched and the low parasitic effect of the small size of the semiconductor chip probe  100 , measurement on the pad under test  301  of the flipped chip  300  has a high bandwidth characteristics and gives measurement results of high accuracy. 
         [0035]    The metal ball  43  as shown in  FIG. 1  to  FIG. 4  and  FIG. 6  may be a solder ball, a bump or a micro-bump that is made of tin, lead, silver or gold. The material of the metal ball  43  is mainly selected from those having a good electrical conductivity. Moreover, each of the metal pads  42  of the measuring unit  40  is further connected to a metal ball  43 , which is electrically connected with a pad of the flipped chip  300  other than the pad under test  301 , to support the flipped chip  300  and supply a DC power to the flipped chip  300  from a outside power source. 
         [0036]    As shown in  FIG. 1  to  FIG. 3  and  FIG. 6 , the connection unit  50  is formed by a signal pad  51  and two ground pads  52  that are disposed at two sides of the signal pad  51  respectively. The signal pad  51  and the two ground pads  52  are not contacted with each other and all expose the dielectric layer  20 , both of the ground pads  52  are electrically grounded, and the signal pad  51  is electrically connected with the second metal wire  32  and inputs the measurement signal from the second metal wire  32 . 
         [0037]    The connection unit  50  as shown in  FIG. 1  to  FIG. 3  and  FIG. 6  is electrically arranged in the ground-signal-ground (GSG) connection way. For the GSG connection way, the signal pad  51  is disposed between the two grounded ground pads  52  to form a high-frequency transmission line in the coplanar waveguide (CPW) form during high-frequency signal transmissions, so the characteristic impedance can be controlled effectively to ensure the quality in the high-frequency signal transmissions. 
         [0038]    As shown in  FIG. 4 , there is shown a conducted EME measurement apparatus  200  with a semiconductor chip probe  100 , the conducted EME measurement apparatus  200  comprises a semiconductor chip probe  100 , a high frequency probe  210 , a signal cable  220  and a test receiver  230 . The semiconductor chip probe  100  is as the semiconductor chip probe  100  described in the embodiments above, and thus will not be further described herein. 
         [0039]    The high frequency probe  210  as shown in  FIG. 4  has three contact pins at one end thereof and an output end at the other end thereof, the three contact pins are electrically connected with the signal pad  51  and the two ground pads  52  of the connection unit  50  respectively and input the measurement signal from the connection unit  50 , and the output end of the high frequency probe  210  outputs the measurement signal. 
         [0040]    Further as shown in  FIG. 4 , the signal cable  220  has an end electrically connected with the output end of the high frequency probe  210 , and the other end of the signal cable  220  is electrically connected with the test receiver  230 . The signal cable  220  completely transmits to the test receiver  230  the measurement signal outputted from the high frequency probe  210 . The signal cable  220  may be a coaxial cable. 
         [0041]    Please also refer to  FIG. 4 , the test receiver  230 , which is electrically connected with the signal cable  220 , inputs the measurement signal from the signal cable  220 , processes or displays the measurement signal. The test receiver  230  may be a spectrum analyzer or an oscilloscope, and most of the test receivers  230  may each comprise one display screen to display the measurement signal. 
         [0042]    In the embodiments as shown in  FIG. 1  to  FIG. 4  and  FIG. 6 , electrical ground pins of the semiconductor chip probe  100 , the high frequency probe  210 , the signal cable  220 , the test receiver  230  and the flipped chip  300  are all electrically connected with each other during actual measurement to ensure the accuracy of the measurement. Moreover, the semiconductor chip probe  100  can input a DC power supply from the outside and supply the DC power supply to the flipped chip  300  through the metal pads  42  and the metal balls  43 . 
         [0043]    The embodiments described above are intended only to demonstrate the technical concept and features of the present invention so as to enable a person skilled in the art to understand and implement the contents disclosed herein. It is understood that the disclosed embodiments are not to limit the scope of the present invention. Therefore, all equivalent changes or modifications based on the concept of the present invention should be encompassed by the appended claims.