KR100484325B1 - Probe card - Google Patents

Abstract

The present invention relates to a probe card having improved durability by preventing an excessive load from being applied to a probe tip provided on a probe head. The probe card of the present invention includes a surface of one side of a board terminal consisting of a plurality of dots or pads. A printed circuit board provided in the center and having a through hole at the center thereof; A head terminal portion formed of a plurality of dots or pads on both surfaces thereof, and a head terminal portion on one surface thereof is electrically connected to an opposite head terminal portion through an internal circuit; A plurality of probe probe tips fixedly installed to be electrically connected to respective terminals of one side of the head terminal part and in contact with the semiconductor in a wafer state; At least two flexible printed circuits (FPCs) each having a multi-layer structure, wherein the printed circuit board and the probe head are electrically connected to each other to electrically connect respective terminals corresponding to the board terminal and the head terminal. Interface means stacked in such a state as to intersect with each other; Reinforcing means for supporting the probe head to enable vertical movement of the probe head; It includes; a base substrate is fixed to one side of the printed circuit board, the reinforcement means is installed.

Description

Probe Card {PROBE CARD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe card for inspecting a semiconductor in a wafer state, and more particularly, to a probe card having improved durability by preventing an excessive load from being applied to a probe tip provided on a probe head. ).

In the semiconductor manufacturing process, after finishing a wafer manufacturing process, a good product is sorted by a probing test, this good product is accommodated in a package, and it finishes in the form of a final product. Then, burn-in is performed for the semiconductor device after the package completed in the form of the final product.

On the other hand, when probing using a probe card and a prober before dicing in a wafer state, in consideration of efficiency, the probe tip of the probe card with respect to the pad (terminal) on the chip area during probing on all integrated circuit chip areas on the wafer. It is ideal to apply voltage and electrical signals by simultaneously touching them.

However, with the current state of the probe card technology it is not possible to contact the probe tips on all chip areas on the wafer and in practice it is desirable to simultaneously contact pads on as many chip areas as possible on the wafer.

As described above, in a probe card, which is a device for inspecting a wafer, that is, a pad, which is a circuit and an output terminal of a semiconductor, a probe tip contacting a substrate terminal portion of a printed circuit board and a pad of a wafer is integrally formed with the probe tip. The array of probe tips, which are electrically connected by needles, which are fixed to the fixed plate by an insulator, are arranged in two rows at positions facing each other and are symmetric to each other.

The probe card configured as described above moves up and down by a jig (not shown) so that the probe tip is in contact with the center of the pad, thereby inspecting the pad for abnormality.

However, the conventional probe card has a structure in which one end of a needle having a probe tip is connected to a circuit of a printed circuit board by soldering or the like, and the needle is fixed to a fixed plate by an insulator.

Therefore, the structure is very complicated, and the manufacturing efficiency and productivity of the probe card is very low because the manufacturing process of the probe card, especially the needle assembly process, has to be performed manually by a skilled worker.

In addition, in the conventional probe card, since a plurality of probe tips are arranged in one direction so as to form a symmetrical row, the probe card to which the needle is applied has a limited number of arrangements of the probe tips. There is a limit to the number of pads that can be inspected using the probe card.

The applicant of the present invention includes a probe head and a probe tip fixed to a bump formed at a height of approximately 100 to 500 μm on the probe head, and a printed circuit board on which the probe head is installed. In a probe card for inspecting semiconductors, first and second flexible printed circuits (FPC) each having a multilayer structure and stacked at a cross angle of 90 ° between the printed circuit board and the probe head. Proposed a probe card that constitutes the interface means of the printed circuit board and the probe head using a circuit).

The probe card of this configuration can eliminate the needle assembly process by hand, thereby improving the manufacturing efficiency and productivity of the probe card, and doubling the number of rows of the probe tip compared to the conventional one. The pad can be inspected.

However, the above-described probe card of the applicant of the present invention adopts a structure in which the printed circuit board supports the probe head, so that some probe tips may be damaged when the probe tips are probed on the pads on the wafer.

That is, when the probe tip is in contact with the pad of the wafer and deforms, the probe tip is excessively deformed if necessary, and in this case, the probe tip is excessively deformed. A breakage of the tip may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a probe card having improved durability by preventing excessive load from being applied to a probe tip provided on a probe head.

The object of the present invention described above,

A printed circuit board having a board terminal portion formed of a plurality of dots or pads on one surface thereof, and having a through hole at a central portion thereof;

A head terminal portion formed of a plurality of dots or pads on both surfaces thereof, and a head terminal portion on one surface thereof is electrically connected to an opposite head terminal portion through an internal circuit;

A plurality of probe probe tips fixedly installed to be electrically connected to respective terminals of one side of the head terminal part and in contact with the semiconductor in a wafer state;

At least two flexible printed circuits (FPCs) each having a multi-layer structure, wherein the printed circuit board and the probe head are electrically connected to each other to electrically connect respective terminals corresponding to the board terminal and the head terminal. Interface means stacked in such a state as to intersect with each other;

Reinforcing means for supporting the probe head to enable vertical movement of the probe head;

A base substrate fixed to one side of a printed circuit board and provided with the reinforcing means;

It is achieved by a probe card comprising a.

According to a preferred embodiment of the present invention, the reinforcing means is a fixing plate fixed to one surface of the base substrate so as to be located inside the through hole, a plate-like spring installed on the fixing plate, a support plate fixed to the spring, It may comprise a support piece for holding and holding the probe head in a state fixed to the support plate, more preferably fixed on the support plate in the state passing through the flexible printed circuit, one end to support the probe head It may further include a support pin.

According to the probe card of such a configuration, when an excessive load is applied to the probe tip, the probe head moves toward the printed circuit board while deforming the spring on the plate, thereby preventing the probe tip from being damaged due to the excessive load. have.

In the present invention, the interface means may be composed of a substrate-side flexible printed circuit disposed on one surface of the printed circuit board, and a head-side flexible printed circuit disposed on one surface of the probe head.

In addition, a noise preventing capacitor may be mounted on one surface of the probe head, and an insertion hole into which the capacitor is inserted may be formed in a head side flexible printed circuit facing the probe head.

Hereinafter, a probe card according to a preferred embodiment of the present invention with reference to the accompanying drawings in detail as follows.

1 illustrates a bottom view of a probe card according to the present invention, and FIG. 2 illustrates a cross-sectional view of a probe card according to an embodiment of the present invention.

As shown, the probe card of the present invention includes a printed circuit board 10 having a through hole 10 'at its center, a probe head 12 provided at the printed circuit board 10, and a probe head 12. A probe tip 14 fixedly installed at the upper side, an interface means for electrically connecting the printed circuit board 10 and the probe head 12, and the probe head 12 to move upward and downward in the probe head 12. And reinforcing means for supporting).

On one surface of the printed circuit board 10, a plurality of substrate terminal portions (not shown) formed of a plurality of dots or pads are provided at various positions on the vertical and horizontal axes, and the probe head 12 is illustrated in FIGS. 3A and 3B. One side surface of the head) is provided with a head terminal portion 12a in contact with each terminal of the interface means, which will be described later, and a head terminal portion 12b through which the probe tip 14 is electrically connected to the other surface of the head 12. Is provided.

Here, the head terminal portions 12a and 12b are formed of a plurality of dots or pads similarly to the board terminal portions.

The probe head 12 is made of an insulating plate such as ceramic, and the inside of the head 12 is provided with a circuit for electrically connecting the head terminal portions 12a, 12b on both surfaces thereof, although not shown.

In addition, bumps 20 are provided in the plurality of rows of terminals constituting the head terminal portion 12b of the probe head 12, respectively, and a probe tip 14 is provided on an upper surface of the bump 20. One end of the c) is welded and fixed by a welding paste (not shown).

Here, the bump 20 allows the probe tip 14 to be in good contact with the pad of the wafer by enabling elastic deformation to the probe head 12 side when the probe tip 14 contacts the pad of the wafer. Nickel (Ni: 20a) or nickel alloy (Ni Alloy) having good conductivity and gold (Au: 20b) provided on the upper surface of the nickel (20a) or nickel alloy are formed from the surface of the probe head 12. It is provided at a height of approximately 100 to 500 mu m, and the probe tips 14 are welded so that one tip row is provided in the space between the two bump rows.

At this time, the probe tip 14 is attached to an adhesive means such as epoxy resin 24 and polymide in a state of being aligned on a tip mounting plate 22 made of ceramic material provided with a row of tip insertion holes. After adhere | attached to the said tip mounting plate 22, it is welded to the bump 20 by the welding paste which is not shown in figure.

Here, the tip mounting plate 22 may be provided with a plurality of rows of tip insertion holes.

Then, the epoxy resin 24 is removed after the probe tip 14 is welded to the bump 20, the tip mounting plate 22 may be provided with a marking for indicating the alignment position of the probe tip.

Meanwhile, in the present embodiment, the interface means for electrically connecting the printed circuit board 10 and the probe head 12 may include at least two flexible printed circuits (FPCs) each having a multilayer structure. Is done.

Specifically, as shown in FIG. 5, the interface means of the present embodiment is a substrate-side and head-side flexible printed circuit 16 which is laminated at a crossing angle of 90 ° between the printed circuit board 10 and the probe head 12. 18).

The board-side flexible printed circuit 16 disposed on the upper surface of the printed circuit board 10 includes an end-side terminal portion 16a electrically connected to a board terminal portion provided on a vertical axis of the printed circuit board 10 and by copper foil. A center side terminal portion 16b is electrically connected to the end side terminal portion 16a through a patterned internal circuit, and the center side terminal portion 16b is provided on the side facing the head side flexible printed circuit 18. .

And the head side flexible printed circuit 18 arrange | positioned at the other surface of the board side flexible printed circuit 16 is the end side terminal part 18a electrically connected with the board terminal part provided on the horizontal axis of the printed circuit board 10. ), A center side terminal portion 18b electrically connected to the center side terminal portion 16b of the substrate-side flexible printed circuit 16, and an end side terminal portion 18a, 18a provided outside the center side terminal portion 18b. And an outer terminal portion 18c electrically connected to the center portion, and the center side terminal portion 18b of the head side flexible printed circuit 18 has one side and a probe head facing the substrate side flexible printed circuit 16 ( The other side facing 12, i.e., formed on both surfaces of the circuit 18, is identical, and the outer terminal portion 18c is formed only on one side facing the probe head 12, or the center terminal portion 18b. The same may be formed on both surfaces of the circuit 18 as shown in FIG.

Here, the center side terminal portion 16b of the board side flexible printed circuit 16 and the center side terminal portion 18b and the outer terminal portion 18c of the head side flexible printed circuit 18 are in the same direction (vertical or horizontal axis). Since the center side terminal portion 16b of the board-side flexible printed circuit 16 is formed in the longitudinal direction of the board-side flexible printed circuit 16, the center side of the head-side flexible printed circuit 18 is formed. The terminal portion 18b and the outer terminal portion 18c are formed in the width direction of the head-side flexible printed circuit 18.

In addition, the terminal portions 16a, 16b, 18a, 18b, and 18c, in particular, a portion in which the central terminal portions 16b and 18b and the outer terminal portion 18c are provided are preferably formed with a neck portion. For the purpose, the polyimide film is further laminated to a thickness of about 0.1 mm at the portion where the terminal portions are provided.

As described above, the remaining portions except for the portions provided with the terminal portions 16a, 16b, 18a, 18b, and 18c are formed in a multilayer structure having about 10 layers to maintain flexibility, and the terminal portions 16a, 16b, and 18a are provided. 18b, 18c is provided in the portion of the polyimide film 26 to be laminated to form a neck portion to maintain the flexibility of the flexible printed circuit, in this case about 20 layers as a whole The effect of a flexible printed circuit having a multi-layer structure of can be exhibited, so that the number of layers of the circuit can not be limited.

Each terminal portion of the substrate-side and head-side flexible printed circuits 16 and 18 having such a configuration has known flip chip bonding method using solder balls and bonding method using solder paste. Or it can adhere with the said terminal part by the bonding method using a conductive adhesive tape, and this adhesion process can be automated by a machine.

Therefore, when the interface means is constructed by using the board side and head side flexible printed circuits 16 and 18, each terminal of the board terminal portion provided on the vertical axis of the printed circuit board 10 has a board side flexible printed circuit ( 16 through the end side terminal portion 16a, the center side terminal portion 16b, the center side terminal portion 18b of the head side flexible printed circuit 18, and the head terminal portions 12a and 12b of the probe head 12. Each terminal of the board terminal portion electrically connected to the probe tip 14 and provided on the horizontal axis of the printed circuit board 10 is an end side terminal portion 18a and an outer terminal portion 18c of the head-side flexible printed circuit 18. The head terminal portions 12a and 12b of the probe head 12 are electrically connected to the corresponding probe tips 14.

In addition, the base substrate 28 is fastened and fixed to the other surface of the printed circuit board 10 by fastening means 30 such as bolts and nuts, and the base substrate 28 is moved up and down in the probe head 12. Reinforcement means for supporting the probe head 12 is installed so that the reinforcement means is fixed to one surface of the base substrate 28 to be located inside the through hole 10 ′ of the printed circuit board 10. ), A plate-shaped spring 34 fixed to the fixed plate 32, a support plate 36 fixed to the spring 34, and a support for fixing and supporting the probe head 12 in a state fixed to the support plate 36. The probe head 12 has one end fixed to the support plate 36 in a state of penetrating the piece 38 and the through holes 16c and 18d of the substrate side and the head side flexible printed circuits 16 and 18, respectively. It consists of a support pin 40 for supporting.

Here, the support pin 40 has a function of preventing the probe head 12 from being locally deformed when the thickness of the probe head 12 is thin so that an excessive load is applied to the probe tip 14.

In addition, the support plate 36 and the support piece 38 may be integrally configured to adjust the parallelism of the probe head 12 on the basis of the support plate 36, and the spring 34 is connected to the support plate 36. It is also possible to form to have a smaller size.

As described above, the probe card after the assembly of each component is moved up and down by a jig (not shown), and thus the probe tip 14 is probed at the pad center on the wafer (not shown), thereby checking whether there is a problem with the pad. When excessive load is applied to part or all of the tip 14, the probe head 12 is pushed toward the through hole 10 'of the printed circuit board 10, thereby deforming the spring 34. Excessive load on (14) can be prevented.

And, as shown in FIG. 6, when the thickness of the probe head 12 'is thick as shown in FIG. 6, since the local deformation of the probe head 12' is prevented due to the thickness, the support pin 40 of FIG. You can also configure with) removed.

The probe card of this configuration may be equipped with a noise preventing capacitor for improved performance.

7 to 9 show a probe card according to another embodiment of the present invention in which the noise preventing capacitor is mounted, and FIG. 7 shows a plan view of the probe head, and FIG. 8 shows a bottom perspective view of the interface means. FIG. 9 is a sectional view of an essential part showing the installation state of the probe head and the interface means.

In the following description of the present embodiment, the same reference numerals are used for the same components as those of the above-described embodiment of the present invention, and only those parts having a different configuration from the above embodiment will be described for simplicity of description.

As shown in the figure, a capacitor 42 is mounted in the space between the terminals on the surface where the head terminal portion 12a of the probe head 12 facing the flexible printed circuit 16 is provided. ) Attenuates the noise of the power supply to improve the performance of the probe card.

However, when the substrate side and the head side flexible printed circuits 16 and 18 are bonded between the printed circuit board 10 and the probe head 12, the probe head 12 and the head side flexible printed circuit 18 are bonded to each other. Since a space corresponding to the height between both terminal portions 12a, 18b, and 18c to which the solder balls 44 are bonded is formed, the capacitor for preventing noise having a height of approximately 250 to 500 μm mounted on the probe head 12 ( There is a problem that 42 is in contact with the neck of the flexible printed circuit 18.

In order to prevent this, in the present embodiment, a condenser insertion hole 46 is formed in the head-side flexible printed circuit 18.

As mentioned in the above-described embodiment of the present invention, the center-side terminal portion 18b of the head-side flexible printed circuit 18 is a substrate-side flexible printed circuit (FPC) by flip chip bonding using solder balls 28. Since it is electrically connected to the center side terminal portion 16b of 16, the head side flexible printed circuit 18 has an internal circuit (patterning by copper foil) for electrically connecting the end side terminal portion 18a and the outer terminal portion 18c. Line only), and no internal circuitry for the center side terminal portion 18b.

Therefore, since there is no need to form an internal circuit in the space between the center side terminal portion 18b and the space between the center side terminal portion 18b and the outer terminal portion 18c, a laser beam or the like is used in this space. To form a capacitor insertion hole 46 having a predetermined width (for example, 0.2 to 3 mm each).

As a result, when the head-side flexible printed circuit 18 and the probe head 12 are bonded together, as shown in FIG. 9, the noise preventing capacitor 42 mounted on the probe head 12 is the head-side flexible printed circuit. Since it is inserted into the capacitor insertion hole 46 of (18), the electrical connection can be easily made between the probe head 12 and the terminal portion of the head-side flexible printed circuit (18).

Therefore, the probe card of this embodiment can easily mount a noise preventing capacitor to the probe head without increasing the bump height.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, in the probe card of the present invention, when an excessive load is applied to the probe tip, the probe head mounted with the probe tip moves upward and downward, thus preventing the probe tip from being damaged due to the excessive load acting on the probe tip. have.

In addition, the interface means for electrically connecting the printed circuit board and the probe head is configured by laminating at least two or more flexible printed circuits having a multi-layer structure in a state where they cross each other, thereby reducing manufacturing efficiency and productivity during the manufacturing process of the probe card. It is possible to eliminate the needle assembly process by hand, which is the main factor, to improve the manufacturing efficiency and productivity of the probe card, and to easily configure the interface means even if the number of terminals of the printed circuit board is increased. Even in this case, the interface means can be effectively configured.

In addition, in the conventional probe card to which the needle is applied, the arrangement of the probe tips is inevitably increased, whereas in the probe card of the present invention, the arrangement of the probe tips can be doubled as compared with the prior art. This can be used to inspect a large number of pads.

Further, the probe card of the present invention has a head-side flexible printed circuit having a condenser insertion hole, so that a bump of a predetermined height or more may be formed to form a gap between the probe head and the head-side flexible printed circuit wider than the height of the condenser. ), Eliminating the problem of increased manufacturing time and cost due to bump formation, and the condenser mounted on the probe head eliminates the electrical connection between the probe head and the corresponding terminals of the head-side flexible printed circuit. There is an effect that can eliminate the problems made irrationally.

1 is a bottom view of a probe card according to the invention.

2 is a cross-sectional view of a probe card according to an embodiment of the present invention.

3A and 3B are top and bottom views of a probe head in accordance with one embodiment of the present invention.

4 is a view showing an installation state of the probe tip according to an embodiment of the present invention.

Figure 5 is a bottom perspective view of the interface means according to an embodiment of the present invention.

6 is a cross-sectional view showing another embodiment of the reinforcing means provided in the probe card of the present invention.

7 is a plan view of a probe head according to another embodiment of the present invention.

8 is a bottom perspective view of an interface means according to another embodiment of the invention.

9 is a cross-sectional view of an essential part showing an installation state of a probe head and an interface means according to another embodiment of the present invention;

Claims (12)

delete delete delete delete delete delete A printed circuit board having a board terminal portion formed of a plurality of dots or pads on one surface thereof, and having a through hole at a central portion thereof; A head terminal portion formed of a plurality of dots or pads on both surfaces thereof, and a head terminal portion on one surface thereof is electrically connected to an opposite head terminal portion through an internal circuit; In the probe card having a plurality of probe probe tips fixedly installed to be electrically connected to each terminal of one side of the head terminal portion and in contact with the semiconductor of the wafer state, At least two flexible printed circuits (FPCs) each having a multi-layer structure, wherein the printed circuit board and the probe head are electrically connected to each other to electrically connect respective terminals corresponding to the board terminal and the head terminal. Interface means stacked in such a state as to intersect with each other; A fixing plate which is positioned inside the through hole and fixed to one surface of the base substrate, a plate-like spring installed on the fixing plate, a support plate fixed to the plate-like spring, and the probe head fixed in the state of being fixed to the support plate. Reinforcement means including a support piece for supporting the probe head so as to support the probe head in a vertical direction; A base substrate fixed to one side of a printed circuit board and provided with the reinforcing means; Probe card comprising a. delete 8. The probe card of claim 7, wherein the reinforcement means is further fixed to the support plate in a state of passing through the flexible printed circuit, and one end of the reinforcement means further comprises a support pin for supporting the probe head. The printed circuit board of claim 7, wherein the interface means comprises a board-side flexible printed circuit disposed on one surface of the printed circuit board and a head-side flexible printed circuit disposed on one surface of the probe head. The board side flexible printed circuit includes an end side terminal portion electrically connected to the board terminal portion, and a center side terminal portion electrically connected to the end side terminal portion through an internal circuit, and the head side flexible printed circuit includes a board terminal portion. An end side terminal portion electrically connected, a center side terminal portion electrically connected to a center side terminal portion of the board side flexible printed circuit, and an end side terminal portion of the head side flexible printed circuit provided outside the center side terminal portion. Probe card having an outer terminal portion electrically connected to the. 11. The probe card of claim 10, wherein a capacitor for preventing noise is mounted on one surface of the probe head, and an insertion portion into which the capacitor is inserted is provided in a head-side flexible printed circuit facing the probe head. 12. The method of claim 10, wherein each terminal of the one side head terminal portion is provided with a bump made of nickel (Ni) or nickel alloy (Ni Alloy) and gold (Au) provided on an upper surface of the nickel or nickel alloy. And the probe tip is welded to the bump such that one tip row is provided in a space between two bump rows.