CN2713630Y - Probe card wrapping structure - Google Patents

Abstract

The utility model relates to a probe card covering structure, which comprises: a circuit board; an insulating fixing ring extending downward from the lower surface of the circuit board; multiple signal lines electrically connected to the circuit board; A plurality of probes are respectively connected to the corresponding signal lines; and a dielectric is used to fix the probes on the insulating fixing ring and cover the signal lines and a predetermined part of the lower surface of the circuit board. The utility model replaces the part suspended in the air by filling the wire pull area of the probe card with an epoxy resin (Epoxy) insulator, so as to improve the high impedance effect of the passing part by the parasitic capacitance effect of this part , to improve the compensation to achieve the purpose of impedance matching, and at the same time reduce energy loss and expand the frequency range of its application.

Description

Probe card wrapping structure

technical field

The utility model relates to a probe card cladding structure, in particular to an insulator filled with epoxy resin (Epoxy) in the wire pull area of the probe card to replace the part suspended in the air. Part of the parasitic capacitance effect is used to improve the high impedance effect of the passing part, and the compensation is improved to achieve the purpose of impedance matching (Impedance Matching) probe card wrapping structure.

Background technique

After the wafer manufacturing is completed, it is necessary to enter the stage of wafer testing to ensure its function. Wafer testing uses a test machine and a probe card (Probe Card) to test each die on the wafer to ensure that the die The electrical characteristics and performance are manufactured in accordance with the design specifications. As chips become more powerful and more complex, the need for high-speed and accurate testing becomes more important.

Among them, the probe card is used for semiconductor integrated circuit wafer (wafer) testing, especially in the radio frequency (RF) wafer-level mass production test. It is used before the integrated circuit (IC) is packaged. The bare chip is tested for function with probes, and defective products are screened out before the subsequent packaging process.

The test process first positions the die on the wafer on the test machine, and then fixes the probe card on the test machine so that the pad on the die is aligned with the probe of the probe card and contacts it .

Please refer to FIG. 1 and FIG. 2 , which are top views and cross-sectional views of conventional conventional epoxy probe cards currently on the market. The probe card 9 includes a circuit board 92, which has an insulating fixing ring 94 extending from its lower surface, and hundreds of probes (Probe) 90, which are fixed on the probe card 9 by epoxy resin 96. On the insulating fixing ring 94. The probes 90 are electrically connected to the printed circuit board 92 and are in electrical contact with the metal pads 84 of the chip 82 on the wafer. The probe 90 is used to contact the bonding pad 84 on the die 82 so as to directly input a signal to the die 82 or detect an output value.

When testing wafers one by one, if the die 82 fails to pass the test, a mark will be marked on the die as a defective product. Then when the wafer is diced and separated, these defective chips will be screened out, and the subsequent packaging process will not be carried out; after the results of the wafer test, the functional chips will enter the next stage of the packaging process .

However, in the structural design of the traditional epoxy resin probe card 9, since the distance between the wiring part and the grounding wire 93 (distributed on the surface of the circuit board 92) is relatively long and long, the formed loop inductance also changes accordingly. If it is large, the impedance mismatch will become more severe; meanwhile, the dielectric 98 between the signal line 91 and the ground line 93 is air, and the electric field will dissipate in the air, and its loss will also increase with the increase of frequency.

Please refer to FIG. 3 , which is a frequency response diagram of a conventional probe card simulation test, and Table 1 below is a comparison table of bandwidths based on S11 , S21 and 3dB in FIG. 3 .

Table I S11 S21 type 100MHz 1GHz 100MHz 1GHz F@3dB Case A -15.03 -1.27 -0.18 -6.17 560MHz Case B -16.79 -2.12 -0.14 -4.43 720MHz

Among them, the simulation test compares two situations, CASE A is the situation where the signal is far from the ground point, CASE B is the situation where the signal is closer to the ground point, and S11 means that the test signal is bounced back due to impedance mismatch, The closer the value is to infinite dB, the better; S21 means that the test signal is completely passed without signal loss, and the closer the value is to 0dB, the better. After the frequency responses S11 and S21 of the simulation test are taken as dB values, a graph as shown in FIG. 3 is obtained. It can be found that once the wire passes through this line, as the frequency increases, its return loss (Return Loss) becomes smaller, and the signal reflection phenomenon will be quite serious; in the high frequency part, its relative insertion loss (Insertion Loss) ) will become larger, and the 3dB bandwidth is only 560-720MHz. With this structure at high frequencies, the signal loss will be very serious, and the energy cannot be transmitted. This situation needs to be improved, especially when electronic products are constantly being introduced at a high speed and the demand for high speed is gradually increasing.

It can be seen that the above-mentioned existing probe card obviously still has inconvenience and defects in actual manufacture and use, and needs to be further improved urgently. In order to solve the problems of the probe card, the related manufacturers have tried their best to find a solution, but no suitable design has been developed for a long time, and the general products do not have a suitable structure to solve the above problems, which is obvious. It is a problem that relevant industry players are eager to solve.

In view of the defects of the above-mentioned existing probe cards, the designer actively conducts research and innovation based on years of rich practical experience and professional knowledge in the design and manufacture of such products, and cooperates with the application of academic theories, in order to create a new type of probe card. The cladding structure of the needle card can improve the general existing probe card and make it more practical. Through continuous research, design, and after repeated trial samples and improvements, the utility model with practical value is finally created.

Contents of the invention

The main purpose of the utility model is to overcome the existing defects of the probe card and provide a new type of probe card coating structure. The technical problem to be solved is the connection method of the traditional epoxy resin probe card Improvements are made to improve the performance of the electrical characteristics and impedance matching of the signal passing through this interface, so that it is more suitable for practical use.

The purpose of this utility model and the solution to its technical problems are achieved by adopting the following technical solutions. A probe card covering structure proposed according to the utility model includes: a circuit board; an insulating fixing ring extending downward from the lower surface of the circuit board; a plurality of signal lines electrically connected to the circuit board a plurality of probes are respectively connected to the corresponding signal lines; and a dielectric is used to fix the probes on the insulating fixing ring and cover the signal lines and a predetermined part of the lower surface of the circuit board.

The purpose of this utility model and the solution to its technical problems can also be further realized by adopting the following technical measures.

The aforementioned probe card covering structure, wherein the lower surface of the circuit board has a ground wire and a signal contact, and the dielectric material extends from the lower surface of the insulating fixing ring along the signal wire to before the signal contact, And cover the ground wire.

The aforementioned probe card covering structure, wherein the lower surface of the circuit board has a ground wire and a signal contact, the dielectric extends from the lower surface of the insulating fixing ring along the signal wire to the signal contact, and Cover the ground wire.

In the aforementioned probe card covering structure, the dielectric medium is an electrical insulator whose dielectric constant is higher than that of air.

In the aforementioned probe card wrapping structure, the dielectric medium is epoxy resin (Epoxyresin).

The purpose of the utility model and its technical problem solving also adopt the following technical schemes to realize. A probe card covering structure proposed according to the utility model includes: a circuit board; an insulating fixing ring extending downward from the lower surface of the circuit board; a plurality of signal lines electrically connected to the circuit board a plurality of probes are respectively connected to the corresponding signal lines; and epoxy resin is used to fix the probes on the insulating fixing ring and cover the signal lines and a predetermined part of the lower surface of the circuit board.

The purpose of this utility model and the solution to its technical problems can also be further realized by adopting the following technical measures.

The aforementioned probe card covering structure, wherein the lower surface of the circuit board has a ground wire and a signal contact, and the epoxy resin extends from the lower surface of the insulating fixing ring along the signal wire to before the signal contact, And cover the ground wire.

The aforementioned probe card covering structure, wherein the lower surface of the circuit board has a ground wire and a signal contact, the epoxy resin extends from the lower surface of the insulating fixing ring along the signal wire to the signal contact, and Cover the ground wire.

Compared with the prior art, the utility model has obvious advantages and beneficial effects. It can be seen from the above technical solutions that in order to achieve the aforementioned object of the invention, the utility model proposes a probe card covering structure, especially by filling the wire pull area of the probe card with an epoxy resin (Epoxy) type insulator to replace the probe card. The part that was originally suspended in the air uses the parasitic capacitance effect of this part to improve the high impedance effect of the passing part, and improve the compensation to achieve the purpose of impedance matching. At the same time, it can reduce energy loss and expand the frequency range of its application. .

With the above technical solution, the probe card covering structure of the present invention has at least the following structural features and advantages:

1. It can improve the return loss of the signal when it passes through the cable, and reduce the problem of impedance mismatch.

2. Make the high-frequency insertion loss lower, increase the effective bandwidth by 3dB, so that the high-frequency signal can be transmitted more completely, and its energy loss can be reduced.

3. Improve the test frequency application range of the epoxy resin probe card and improve the quality of signal transmission.

To sum up, the special probe card cladding structure of the present invention improves the connection method of the traditional epoxy resin probe card, which can improve the electrical characteristics and impedance matching performance of the signal passing through this interface. It has the above-mentioned many advantages and practical value, and there is no similar structural design publicly published or used in similar products, so it is indeed innovative. It has great improvements in both structure and function. It has made great progress, and has produced easy-to-use and practical effects, and has improved multiple functions compared with the existing probe cards, so it is more suitable for practical use, and has wide application value in the industry. It is a novelty and progress. , Practical new design.

The above description is only an overview of the technical solution of the present utility model. In order to further clearly understand the features and technical content of the present utility model, and implement it according to the contents of the specification, the following is a preferred embodiment of the present utility model with accompanying drawings Details are as follows.

Through the description of specific embodiments, one can get a deeper and more specific understanding of the technical means and effects of the utility model to achieve the intended purpose, but the attached drawings are only for reference and description, and are not used to explain the present invention. Utility models are restricted.

Description of drawings

FIG. 1 is a top view of a conventional epoxy resin probe card.

FIG. 2 is a cross-sectional view of a conventional epoxy resin probe card.

FIG. 3 is a frequency response diagram of a conventional probe card simulation test.

Fig. 4 is a top view of the probe card of the present invention.

Fig. 5 is a sectional view of the probe card of the present invention.

Fig. 6 is the improved design of the utility model and the simulated frequency response diagrams of S11 and S21 when the conventional wire crosses the incomplete surface.

1: Probe card 10: Probe

11: Signal line 14: Insulation fixing ring

12: Circuit board 15: Signal contact

13: Ground wire 16: Dielectric material

82: Die 84: Welding pad

9: Probe card 90: Probe

91: Signal line 92: Circuit board

93: Ground wire 94: Insulation fixing ring

96: epoxy resin 98: dielectric

Detailed ways

In order to further explain the technical means and effects of the utility model to achieve the intended purpose of the invention, below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation, structure, Features and their functions are described in detail below.

Please refer to FIG. 4 and FIG. 5 , which are a top view and a cross-sectional view of a probe card according to a specific preferred embodiment of the present invention. The probe card 1 has a circuit board 12, an insulating fixing ring 14 extends downward from the lower surface of the edge of the circuit board 12, a plurality of probes 10 are electrically connected to the circuit board 12, and a dielectric 16 fixes the probes. The needle 10 is on the insulating fixing ring 14 . Wherein the lower surface of the circuit board 12 has a ground wire 13 and a signal contact 15 .

In order to improve the connection mode of the epoxy resin probe card, the connection from the test machine to the die 82 to be tested is through the signal wiring of the probe card 1, and then through the wire (usually tungsten or tungsten) alloy), that is, the signal line 11, to connect to the die 82 itself. This structure can be divided into two parts, one is the circuit board 12 of the probe card 1, and the other is the signal line 11 part. In the structural part of the circuit board 12 of the probe card 1, impedance control and high-speed and high-frequency signal transmission can be achieved by proper stacking and grounding/power plane design; but in the signal line 11 part, then It is to pull the signal contact 15 of the probe card 1 to the solder joint 84 of the chip 82. The signal quality of this part needs to be well-designed impedance matching to reduce the impedance caused by the mismatch between the two terminals. Reflection affects the quality of signal transmission.

According to the above analysis, the utility model is characterized in that the cladding structure of the probe card is improved, and a dielectric 16 is provided to fix most of the signal line 11 of the probe 10 and cover the insulating fixture 14 and the circuit board. 12 ground wires 13 parts. By using a dielectric material 16 with a higher dielectric constant (dielectric constant) than air, such as epoxy resin (epoxy resin), instead of using air as the medium between the signal line 11 and the ground line 13 in the traditional probe card Electric quality, and avoid its electric field from dissipating in the air, so that its loss will not increase with the increase of frequency. Therefore, when the signal line passes through the non-pull line, the resulting impedance mismatch can be surrounded by the filling resin or similar dielectric (insulator) of the present utility model to surround the signal line and the ground line, so that part of the parasitic capacitance effect can be eliminated. Improve the high impedance effect of the passing part, improve the compensation to achieve the purpose of impedance matching, and reduce the dissipation of energy from the air.

In the present invention, as long as the range of the dielectric 16 is slightly larger than the conventional coverage, it can effectively prevent the electric field from escaping in the air, for example, it can cover part of the circuit board 12, or can completely cover the entire circuit board 12. When the dielectric 16 covers a part of the circuit board 12 , the signal contact 15 is not covered, and the probe 10 can still be replaced. Therefore, its range can extend from the lower surface of the insulating fixing ring 14 to the end of the signal line 11 , that is, in front of the signal contact 15 , or can extend to cover the signal contact 15 .

Please refer to shown in Fig. 6, it is the improved design of the present utility model and the analog frequency response diagram of S11 and S21 that the existing conventional wire passes through the incomplete surface, and the following table two is the data comparison table according to Fig. 6, That is, according to the bandwidth comparison table of S11, S21 and 3dB in Fig. 6 .

Table II S11 S21 type 100MHz 1GHz 100MHz 1GHz F@3dB Case A -15.03 -1.27 -0.18 -6.17 560MHz Case B -16.79 -2.12 -0.14 -4.43 720MHz Case C -21.50 -5.52 -0.09 -1.82 1.38GHz

The utility model uses the structure of Fig. 6 to improve the probe card, wherein the equivalent approximate formula of impedance is √(L/C), wherein L is the equivalent inductance, and C is the equivalent capacitance, so if To reduce impedance, it is necessary to lower the L value and increase the C value. The dielectric constant of air is 1, and the dielectric constant of epoxy resin is about 3.5, so the value of C can be effectively increased.

The utility model is characterized in that the signal line and the grounding line are surrounded by an insulating material with a high dielectric constant, such as epoxy resin (Epoxy resin), as the dielectric material to increase the effective capacitance effect. Use this part of the parasitic capacitance effect to improve the purpose of achieving impedance matching through its own high impedance effect. At the same time, epoxy resin (Epoxy resin) or similar insulating substances are used to surround the line and the grounding line to limit the distribution of the electric field and avoid energy loss caused by escaping in the air.

The utility model replaces the traditional probe card with a higher dielectric material, and uses air as the dielectric between the signal line and the grounding line, so as to avoid the electric field from escaping in the air, so that the loss will not increase with the increase of frequency. get bigger. In this way, it will be able to improve its return loss, reduce the phenomenon of impedance mismatch, and at the same time reduce its insertion loss, increase its bandwidth by 3dB, double its effective application bandwidth, and facilitate the transmission of high-frequency and high-speed signals .

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model in any form. Although the utility model has been disclosed above with preferred embodiments, it is not intended to limit the utility model. Any skilled person who is familiar with the profession can use the technical content disclosed above without departing from the scope of the technical solution of the utility model. Make some changes or modifications to equivalent embodiments of equivalent changes, but any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the utility model without departing from the content of the technical solution of the utility model shall be Still belong to the scope of the technical solution of the utility model.

Claims (8)

1, a kind of probe clad structure is characterized in that it comprises:

One circuit board;

One insulation retainer ring is that the lower surface by this circuit board extends downwards;

The plural number signal line is to electrically connect this circuit board;

The plural number probe is to connect this corresponding signal line separately; And

Dielectric medium is to fix this probe on the insulation retainer ring, and coats a predetermined part of this signal line and this circuit board lower surface.

2, probe clad structure according to claim 1, the lower surface that it is characterized in that wherein said circuit board has earth connection and signal contact, this dielectric medium is before the lower surface of this insulation retainer ring extends to this signal contact along this signal line, and coats this earth connection.

3, probe clad structure according to claim 1, the lower surface that it is characterized in that wherein said circuit board has earth connection and signal contact, this dielectric medium is that the lower surface from this insulation retainer ring extends to this signal contact along this signal line, and coats this earth connection.

4, probe clad structure according to claim 1 is characterized in that wherein said dielectric medium is to be the higher electrical insulators of the dielectric constant of its permittivity ratio air.

5, probe clad structure according to claim 1 is characterized in that wherein said dielectric medium is to be epoxy resin (Epoxy resin).

6, a kind of probe clad structure is characterized in that it comprises:

One circuit board;

One insulation retainer ring is that the lower surface by this circuit board extends downwards;

The plural number signal line is to electrically connect this circuit board;

The plural number probe is to connect this corresponding signal line separately; And

Epoxy resin is to fix this probe on the insulation retainer ring, and coats a predetermined part of this signal line and this circuit board lower surface.

7, probe clad structure according to claim 6, the lower surface that it is characterized in that wherein said circuit board has earth connection and signal contact, this epoxy resin is before the lower surface of this insulation retainer ring extends to this signal contact along this signal line, and coats this earth connection.

8, probe clad structure according to claim 6, the lower surface that it is characterized in that wherein said circuit board has earth connection and signal contact, this epoxy resin is that the lower surface from this insulation retainer ring extends to this signal contact along this signal line, and coats this earth connection.

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