TW201506408A - Probe card - Google Patents

Abstract

The present invention provides a probe card having a space transformer, a printed circuit board (PCB), and a probe assembly. The space transformer includes a top surface, a bottom surface, an annular lateral surface, and at least one lateral electrode. The annular lateral surface is located between the top and bottom surfaces. The at least one lateral electrode is located on the annular lateral surface and connected with a tester. The PCB is electrically connected with the space transformer and located on the top surface of the space transformer. The probe assembly is electrically connected with the space transformer and located on the bottom surface of the space transformer. In this way, the probe card of the present invention can increase usable test channels by means of the lateral electroide.

Description

Probe card

The present invention relates to a probe card structure, and more particularly to a probe card having at least one side electrode on a space transformer.

In a semiconductor process, a probe card is generally used to test whether a die on a wafer is good.

However, as the pad on the die increases, or the size of the wafer decreases, the spacing between adjacent pads decreases. Therefore, the probe card must also conform to the reduction of the pad pitch, and a probe card having a space transformer (ST) is developed, and the space converter is located on the chip and a printed circuit board (printed circuit board). Between the PCBs, and electrically connecting the pads of the wafer and the printed circuit board to convert the pads of the pitch configuration to the printed circuit board of the pitch configuration.

In addition, the space converter is usually a structure of a multi-layer substrate, and the connection with the printed circuit board is soldered with solder balls or solder paste to form an electrical connection between the space converter and the printed circuit board. And transmit a telecommunication signal. However, in practice, the connection of solder balls or solder paste will attenuate the high-frequency signal and the impedance of the power supply. Further, if the size of the solder ball is too large, the test channel such as the transmission signal that can be used by the probe card can be reduced. Quantity.

The layers of the substrate in the space converter are usually connected by vias to transmit electrical signals, but too many through holes will destroy the electrical integrity of the layers.

In addition, with the increasing demand for high-speed operation of electronic products, there is still a need to consider the high-speed operation requirements of electronic components. The conventional technology uses a flexible circuit board to connect the space converter and the printed circuit board to enable the high-frequency signal test requirement. Or the power signal test requirement can be transmitted by the flexible circuit board alone. However, the prior art does not solve the problem that the substrate of each layer of the space converter is connected by a via, so that the high frequency signal test requirement or the power signal test is required. The effect of demand is limited. Furthermore, the prior art cannot solve the problem that the size of the solder ball is too large, so that the number of telecommunication test channels that can be used is limited.

In view of the above-mentioned deficiencies, the main object of the present invention is to provide a probe card having at least one side electrode by a space converter in the probe card to increase the number of test channels for transmitting electrical signals.

A secondary object of the present invention is to provide a probe card, wherein the space converter in the probe card has at least one side electrode, and the at least one side electrode has a function of conducting the upper and lower metal layers inside the space transformer, so Reduce the use of through-holes inside the space transformer and improve power integrity.

To achieve the above object, the present invention also provides a probe card comprising a space transformer, a printed circuit board and a probe set. The space transformer has a top surface, a bottom surface, a ring side surface and at least one side electrode. The side of the ring is tied between the top surface and the bottom surface. The at least one side electrode is located on the side of the ring and is electrically connected to a testing machine. The printed circuit board is electrically coupled to the space transformer and is located on a top surface of the space transformer. The probe set is electrically connected to the space transformer and is located on the bottom surface of the space transformer.

10‧‧‧ probe card

11, 11a, 11b, 11c‧‧‧ space converter

111‧‧‧ top surface

113‧‧‧ bottom

115, 115a~115c‧‧‧ ring side

117, 117a~117f‧‧‧ side electrodes

119‧‧‧Conducting plane

121, 121a, 121b‧‧‧ through holes

13‧‧‧Printed circuit board

15‧‧‧ probe set

151‧‧‧ probe

18, 18a‧‧‧ solder balls

20, 20a‧‧‧ test machine

21a‧‧‧ connector

31‧‧‧ Space Converter

33‧‧‧ first unit

35‧‧‧Second unit

37‧‧‧Electrical film

39‧‧‧side electrode

40‧‧‧ Probe Card

41‧‧‧Press ring

431‧‧‧side electrode

43‧‧‧ Space Converter

45‧‧‧Printed circuit board

50‧‧‧ probe card

51‧‧‧ transmission line

53‧‧‧ Space Converter

531‧‧‧side electrode

533‧‧‧ first side

535‧‧‧ ring side

537‧‧‧ second side

55‧‧‧Printed circuit board

551‧‧‧Perforation

553‧‧‧ upper surface

555‧‧‧ lower surface

61‧‧‧ transmission line

611‧‧‧Seat

631‧‧‧side electrode

633‧‧‧ first side

635‧‧‧ second side

65‧‧‧Printed circuit board

651‧‧‧ upper surface

71‧‧‧side electrode

711‧‧‧ socket

73‧‧‧ transmission line

731‧‧‧ plug

75‧‧‧Printed circuit board

751‧‧‧ upper surface

1 is a schematic view of a probe card in accordance with a preferred embodiment of the present invention.

Figure 2 is a perspective view showing the first type of space transformer having side electrodes.

Figure 3 is a perspective view showing a second type of space transformer having side electrodes.

Figure 4 is a perspective perspective view of a third type of space transformer having side electrodes.

Figure 5 is a top plan view of a fourth space transformer with side electrodes.

Fig. 6 is a schematic view showing the structure of another space converter having side electrodes.

Figure 7 is a partially enlarged schematic view showing the electrical connection of the side electrodes and the printed circuit board by means of a press-fit coil.

8 and 9 are respectively partially enlarged schematic views showing the electrical connection of the side electrodes and the printed circuit board by the transmission line.

FIG. 10 is a partially enlarged schematic view showing another transmission line electrically connecting the side electrodes and the testing machine.

Figure 11 is a partially enlarged schematic view showing another transmission line electrically connecting the side electrodes and the printed circuit board.

Since the present invention discloses a probe card for testing semiconductor or optoelectronics, wherein the principle and basic functions of the probe card are well known to those skilled in the relevant art, the following description will not be made. Full description. At the same time, the drawings referred to in the following texts express the structural schematics related to the features of the present invention, and do not need to be completely drawn according to the actual size, which will be described first.

Fig. 1 is a schematic view showing a probe card of a first preferred embodiment of the present invention. As shown in the first figure, the probe card 10 of the present invention includes a space transformer 11, a printed circuit board 13, and a probe set 15. The space transformer 11 has a top surface 111, a bottom surface 113, a ring side surface 115, at least one side electrode 117 and at least one conductive plane 119. The side surface 115 of the ring is located between the top surface 111 and the bottom surface 113. The at least one side electrode 117 is located on the side surface 115 of the ring and electrically connected to a testing machine 20. The conductive plane 119 can also be a conductive trace, that is, the conductive plane 119 can be a plane or a trace path. In addition, the conductive plane 119 can be a power plane/trace, a ground plane/trace, or a signal plane/trace, and can be located in the space converter. The top surface 111, the bottom surface 113 of the 11 is the inside of the space transformer 11. The conductive planes 119 are preferably copper foils. However, other metal conductive materials such as silver may be used in practice, so the conductive plane 119 is not limited to copper foil. If the conductive plane 119 is a power plane, it is used to transmit a power signal; if the conductive plane 119 is a ground plane, it is used to provide a ground reference level of the signal. The printed circuit board 13 is electrically connected to the space transformer 11 and is located on the top surface 111 of the space transformer 11. The probe set 15 is electrically connected to the space transformer 11 and is located on the bottom surface 113 of the space transformer 11. The probe set 15 has a plurality of probes 151. It is to be noted that in the first drawing, in order to clearly explain the relationship between the probe set 15 and the space transformer 11, a large number of probes are omitted, and only a part of the probes 151 are shown. The connection mode of the at least one side electrode 117 with the printed circuit board 13 or the testing machine 20 will also be described later.

In addition, the probe card 10 of the present invention still retains the conventional technology of forming a test channel for transmitting electrical signals by the solder balls 18. However, the technology of using the solder balls 18 has been widely used in the industry, and therefore will not be described again.

Figure 2 is a perspective perspective view of a space transformer with side electrodes. As shown in Fig. 2, the dotted line portion is the outer contour of the space transformer 11. In the first preferred embodiment, the space transformer 11 has a plurality of side electrodes 117 and a plurality of conductive planes 119. The side electrodes 117 are respectively located on the side 115 of the ring. The space transformer 11 also has a plurality of through holes 121. The through holes 121 are respectively perpendicularly penetrated through the top and bottom surfaces 111 and 113 of the space transformer 11, and the inner wall surfaces of the through holes 121 are plated with a conductive material such as copper, tin or silver to make the holes. The through holes 121 are electrically connected to the conductive planes 119, respectively, to form a test channel for transmitting electrical signals.

It should be noted that, referring to FIG. 2, since the side electrodes 117 are electrically connected to the conductive planes 119 inside the space transformer 11, the through holes 121 inside the space transformer 11 can be reduced. Therefore, the power integrity of the conductive planes 119 can be improved. Moreover, the diameter of the through hole 121 is about 0.1 mm. Since the size of the side electrodes 117 is larger than the size of the through holes 121, the resistance and impedance discontinuity generated by the through holes 121 can be reduced, and the impedance value can be lowered. Furthermore, since the use of the side electrodes 117 can reduce the use of the through holes 121, the integrity of the metal inside the multilayer substrate in the space transformer 11 can be increased, and therefore, the power source impedance can be further reduced.

In addition, when the side electrodes 117 are applied to the high frequency signal transmission, the high frequency signal can be prevented from passing through the through hole 121 of the space transformer 11 or the solder ball located outside the space transformer 11, so that the high frequency signal transmission can be shortened. distance. Moreover, the size of the side electrodes 117 can also be designed according to the matching impedance to reduce the discontinuity of the connection of the conductive planes 119, thereby increasing the testable bandwidth. When the side electrodes 117 are applied to the transmission of the power signal, they can also be used to reduce the power source impedance.

Figures 3 and 4 show perspective perspective views of another space transformer with side electrodes, respectively. The dotted line portion is the outer contour of the space transformers 11a, 11b. As shown in Fig. 3, the side electrodes 117a are respectively in the shape of an arc and are arranged on the side surface 115a of the ring to form a shape such as a stamp edge. The curved side electrodes 117a use a general circuit board/PCB A standard process on the side of the stamp is formed on the space transformer 11a. As shown in FIG. 4, the side electrodes 117b are each in a rectangular shape and are arranged on the ring side surface 115b. The rectangular side electrodes 117b may be formed on the space transformer 11b by ceramic printing or electroplating. Therefore, the side electrodes on the space transformer of the present invention can be a standard process, so the characteristics are consistent, and can be quickly completed.

Referring to Figure 5, a top view of a space transformer having side electrodes is shown. The test channel of a conventional space transformer must pass through the solder ball 18a. The number of the solder balls 18a is usually 2,500, that is, a 50 ^* 50 BGA/ball grid array. However, in addition to the above 2,500 test channels, the space converter 11c of the present invention may additionally add a test channel capable of transmitting a high frequency signal or a power signal. That is to say, each of the 50 side electrodes 117e can be added to the four sides (i.e., the ring side 115c) by the space transformer 11c, so that an additional 200 test channels can be added. Further, the number of the test channels of the space transformer 11C can be made 2,700 (2500+50 ^* 4=2700). In particular, the four corners of the space transformer 11c may also be provided with side electrodes 117f, respectively, such that the total number of the test channels reaches 2,704. In the case where the space converter 11c has 2,704 total number of test channels, the space converter 11c of the present invention is increased by 8% of the number of test channels compared to the conventional space transformer. Therefore, with the probe card of the present invention, since the space transformer 11c has the side electrodes 117e, 117f, the number of test channels can be additionally increased; of course, the use of the through holes 121 can be further reduced. Therefore, the space transformer 11c can design the number of test channels required by adjusting the number of the side electrodes 117e, 117f. Moreover, in another embodiment, since the space converter has the side electrodes, the use of the through holes in the space converter can be reduced, thereby reducing the number of BGA/tin balls, and thus the individual BGAs can be added. / The area of the solder ball meets and meets the BGA/tin ball size specifications, thus facilitating packaging. In addition, it should be particularly noted that the probe card of the present invention also conforms to the following relationship. That is, the space converter of the present invention has M side electrodes, the printed circuit board 13 has N pads (not shown), and the probe set 15 has T probes 151, wherein M, N and T are positive integers, and the sum of M and N is greater than or equal to T.

Next, the manner in which the at least one side electrode is connected to the printed circuit board or to the test machine will be described.

As shown in FIG. 6, the space transformer 31 further has a first unit 33, a second unit 35 and a thin film 37. The outer side of the first unit 33 is surrounded by the side 331 of the ring, and the side electrodes 39 are located on the side 331 of the ring. The first unit 33 may be made of a multi-layer ceramics (MLC) material or a multi-layer organic (MLO) material. The second unit 35 is made of a multi-layer organic (MLO) material, and the thickness T of the second unit 35 is preferably less than 1 mm. The conductive film 37 is electrically connected to the first unit 33 and the second unit 35 and is located between the first unit 33 and the second unit 35.

In particular, the second unit 35 can be a flex-rigid bonded circuit board. Wherein, the guest soft-hard combined circuit board is taken from a common multi-layer organic (MLO) provided by the client, that is, the flex-rigid combination used in the present invention. The circuit board is a common package substrate used by the client for product packaging, rather than being opened again.

Furthermore, it is to be noted that the space transformer used in the present invention can also be fabricated in a single layer ceramic structure or in a plurality of layers of organic junction materials. Alternatively, the conductive film 37 is omitted, and the surface of the multilayer ceramic structure and the multilayer organic structure is bonded by a pre-welded electrical connection to form the space transformer. Therefore, the structure of the space transformer is not limited to that depicted in FIG.

As shown in FIG. 7, the probe card 40 further includes a press ring 41. The pressing ring 41 is electrically connected to at least one side electrode 431 of the space transformer 43 and the printed circuit board 45, and the pressing ring 41 is located on the printed circuit board 45 and the at least one side electrode 431. between. The side electrode 431 is generally larger and thicker than the side electrode of the preferred embodiment described above, so that the press ring 41 can positively electrically connect the side electrode 431 and the printed circuit board 45.

As shown in FIG. 8, the probe card 50 further includes a transmission line 51 electrically connected to at least one side electrode 531 of the space transformer 53 and the printed circuit board 55. The transmission line 51 may be a coaxial cable or Flexible printed circuit (FPC) can be selected according to actual needs. The transmission line 51 is for transmitting electrical signals. One end of the transmission line 51 is electrically connected to the first side surface 533 of the at least one side electrode 531, and the other end of the transmission line 51 passes through a through hole 551 of the printed circuit board 55, and electrically connects the printed circuit board Upper surface of 55 553. The first side 533 of the side electrode 531 is opposite the ring side 535 of the space transformer 53. The through hole 551 passes through the upper and lower surfaces 553 and 555 of the printed circuit board 55.

As shown in FIG. 9, one end of the transmission line 51 can also be selectively connected to the second side 537 of the side electrode 531, and the second side 537 of the at least one side electrode 531 is positively facing the printed circuit board 55. The lower surface 555 is not limited to the connection position depicted in FIG.

As shown in FIG. 10, the printed circuit board 65 has at least one socket 611 which is fastened to the upper surface 651 of the printed circuit board 65. One end of the transmission line 61 is electrically connected to the socket 611. The other end of the transmission line 61 is electrically connected to the first side 633 of the at least one side electrode 631. The other end of the transmission line 61 can also be electrically connected to the second side 635 of the at least one side electrode 631. Therefore, the other end of the transmission line 61 is electrically connected to the at least one side electrode 631. Figure 10 is limited to the limit. The socket 611 of the upper surface 651 of the printed circuit board 65 is used to electrically connect the connector 21a of the testing machine 20a. Thus, the testing machine 20a can also transmit an electrical signal to the side electrode 631 or receive the side electrode 631. The telegraph number. In practice, the transmission line 61 can also be connected to the testing machine 20a by other means, so it is not limited to the socket 611 and the joint 21a.

As shown in Fig. 11, the side electrode 71 has at least one socket 711, and the opening of the at least one socket 711 faces outward. The transmission line 73 has at least one plug 731. The at least one plug 73 is located at one end of the transmission line 73 and is inserted into the at least one socket 711 of the side electrode 71 to form an electrical connection. The other end of the transmission line 73 is electrically connected to the upper surface 751 of the printed circuit board 75. Therefore, the transmission line 73 can be easily inserted on the side electrode 71 without being limited by soldering.

In summary, it can be seen from the above preferred embodiments that the number of the side electrodes can be adjusted according to the number of test channels, and the manner of electrically connecting the side electrodes is numerous, so it is not preferred. The examples are limited. Moreover, the shape of the side electrodes is not limited to the above preferred embodiment. In addition, the shapes, sizes, and numbers of the conductive planes are not fixed, but are designed according to actual needs; and the conductive planes may also be disposed on the top or bottom surface of the space transformer, so The interior of the space converter is limited.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; the above description should be understood by those skilled in the art and The equivalent changes or modifications made without departing from the spirit of the invention are intended to be included in the scope of the claims.

10‧‧‧ probe card

11‧‧‧ Space Converter

111‧‧‧ top surface

113‧‧‧ bottom

115‧‧‧ ring side

117‧‧‧side electrode

119‧‧‧Conducting plane

13‧‧‧Printed circuit board

15‧‧‧ probe set

151‧‧‧ probe

20‧‧‧Testing machine

18‧‧‧ solder balls

Claims (12)

A probe card comprising: a space converter having a top surface, a bottom surface, a ring side surface and at least one side electrode, the ring side being tied between the top surface and the bottom surface, the at least one side electrode Lying on the side of the ring and electrically connected to a test machine; a printed circuit board electrically connected to the space converter and located on the top surface of the space transformer; and a probe set electrically connected to the A space transformer is located on the underside of the space transformer. The probe card of claim 1, wherein the space converter further has at least one conductive plane electrically connected to the at least one side electrode and located on the top surface of the space transformer, The bottom surface or the interior of the space converter. The probe card of claim 2, wherein the conductive plane is a power plane and is located inside the space converter. The probe card of claim 1, wherein the space transformer has M side electrodes, the printed circuit board has N pads, and the probe set has T probes, wherein M , N and T are positive integers, and the sum of M and N is greater than or equal to T. The probe card of claim 1, wherein the space converter further has a first unit, a second unit and a conductive film, the first unit having the ring side wrapping, the at least one The side electrode is located on the side of the ring, wherein the conductive film is located between the first unit and the second unit, and electrically connects the first unit and the second unit. The probe card of claim 5, wherein the first unit is a multilayer structure made of a ceramic material or an organic material, and the second unit is a multilayer structure made of an organic material, and the first unit The second unit has a thickness of less than 1 mm. Such as the probe card described in claim 1, 2, 3, 4, 5 or 6, wherein the space The converter further has a plurality of through holes, each of which extends through the top and bottom sides of the space transformer, and the size of each of the consistent holes is smaller than the size of the at least one side electrode. The probe card of claim 1, further comprising a press ring electrically connecting at least one side electrode of the space transformer and the printed circuit board, and the press ring is located in the printed circuit Between the plate and the at least one side electrode. The probe card of claim 1, further comprising a transmission line electrically connecting at least one side electrode of the space transformer and the printed circuit board, the transmission line being selected from the group consisting of a coaxial cable and a soft A group of printed circuits. The probe card of claim 9, wherein the printed circuit board has an upper surface and a lower surface, the lower surface is corresponding to the top surface of the space transformer, and one end of the transmission line is electrically connected to the The first surface of the transmission circuit is electrically connected to a first side of the at least one side electrode or a second side of the at least one side electrode, the first side of the at least one side electrode The side surface is opposite the side of the ring of the space transformer, and the second side of the at least one side electrode corresponds to the lower surface of the printed circuit board. The probe card of claim 9, wherein the printed circuit board has an upper surface, a lower surface, and at least one socket, the lower surface corresponding to the top surface of the space converter, the at least one The socket is fastened to the upper surface of the printed circuit board, the at least one socket is electrically connected to the at least one connector of the testing machine, and one end of the transmission line is electrically connected to the at least one socket, and the other end of the transmission line is Electrically connecting a first side of the at least one side electrode or a second side of the at least one side electrode, the first side of the at least one side electrode being opposite to the side of the ring of the space transformer, The second side of at least one of the side electrodes corresponds to the lower surface of the printed circuit board. The probe card of claim 10, wherein the at least one side electrode has at least one socket, the opening of the at least one socket is outward, and the other end of the transmission line has at least one plug. For inserting into the at least one socket.