KR100823311B1 - Method for manufacturing probe card and probe card thereby - Google Patents

Abstract

A method for fabricating a probe card is provided to improve uniformity of a body part of a probe by eliminating the necessity for simultaneously forming the body part and a tip part of the probe by a metal plating method. A first photoresist layer is formed in a manner that a bump region connected to the upper surface terminal of a substrate is excepted wherein the upper surface terminal is connected to an interconnection part(151) in the substrate. A conductive material is filled in the bump region to form a bump. An elastic layer surrounds the periphery of the bump. A second photoresist layer is formed on the elastic layer, patterned in a manner that a body part region extended from the bump in more than one direction is excepted. A conductive material is filled in the body part region to form a body part. A trench is formed on a sacrificial substrate. A conductive material is filled in the trench to form a tip part. The tip part is bonded to the body part. The process for forming the elastic layer can include the following steps. After the first photoresist layer is removed, the elastic layer is formed on the substrate.

Description

Method for manufacturing probe card and probe card manufactured thereby

1A to 1G sequentially illustrate a method of forming a first bump on a substrate in a method of manufacturing a probe card according to an embodiment of the present invention.

2A and 2B sequentially illustrate a method of forming a second bump on a first bump of a method of manufacturing a probe card according to an embodiment of the present invention.

3A to 3C sequentially show a method of forming an elastic layer in the method of manufacturing a probe card according to an embodiment of the present invention.

Figures 4a to 4f sequentially shows a method of forming a body portion of the probe card manufacturing method according to an embodiment of the present invention.

5A to 5I sequentially illustrate a method of forming a probe tip portion on a sacrificial substrate in a method of manufacturing a probe card according to an embodiment of the present invention.

6 shows a method of attaching the tip formed by FIGS. 5A-5I to the body formed by FIGS. 4A-4F of the method of manufacturing a probe card according to an embodiment of the present invention.

The present invention relates to a probe card manufacturing method and a probe card produced thereby. Specifically, the present invention relates to a probe card manufacturing method and a probe card by the novel probe forming method.

The probe card is mounted to a probing apparatus and used to electrically test each individual semiconductor element or liquid crystal display panel formed on the wafer.

In this case, the probe (or electrical contact element) provided in the probe card contacts the metal pad which is the contact portion of each individual semiconductor element formed on the wafer or the contact portion of each pixel of the liquid crystal display panel so that the test can be performed.

Recently, as a method of forming a probe card, a method of forming a plurality of probes at once on a space transformer, which is a type of a circuit board that is in contact with a printed circuit board, using a MEMS process, which is similar to a semiconductor etching technique, has been described. It is being tried. In the method of forming a probe card by the MEMS process, a plurality of probes are simultaneously formed by repeating a photoresist process, an etching process, a metal deposition process, and a fine grinding process, thereby making the horizontal and vertical positions and heights of the plurality of probes uniform. There are advantages to it.

Forming a bump on the upper portion of the wiring portion for transmitting the electrical signal from the space transformer to a method of manufacturing a probe card by the MEMS process, and then forming a body portion having a predetermined length on the upper portion of the bump, the predetermined body portion It is known to manufacture by growing a tip in a predetermined shape and height in a region.

By the way, according to the conventional method of manufacturing a probe card, when forming a plurality of probes at the same time, when growing a plurality of tips in the upper portion of the plurality of body parts, it is difficult to grow all the tips of the plurality of tips uniformly and also such growth The method itself has the disadvantage that it is not easy to implement. In addition, according to the conventional method of manufacturing a probe card, since the substrate is formed from the probe bump to the tip of the probe, the process of laminating, etching, and polishing the photoresist layer on the substrate must be repeated several times. Therefore, the manufacturing process time is increased, there is a disadvantage that damage to the substrate due to the stress caused by this repeated process.

In addition, according to the conventional method of manufacturing a probe card, the bump and the body of the probe, or the body and the tip portion are formed by the metal plating method at the same time. However, when plating the bump and the body or the body and the tip at the same time, since the shape of the metal mold for the plating is composed of a three-dimensional shape, the plating is not sufficiently performed in the plating process, and thus voids are formed between the bump and the body or the body and the tip. Can be formed.

In addition, in this long-term metal plating process, the probe body may be formed unevenly, and thus, it is necessary to perform a long-term polishing process for making the formed probe body uniform. However, during such a long polishing process, damage is often caused to the bumps and the body, or to the joint portion of the body and the tip. When the damaged probe is brought into contact with the contact pad of the semiconductor element, the probe is easily broken by the contact pressure.

In order to solve the above technical problem, the present invention is to provide a method for manufacturing a probe card by forming the tip portion and the body portion separately from the probe to suppress the generation of voids when forming the probe tip portion, a long-term polishing process is unnecessary.

In addition, the present invention is to provide a method of manufacturing a probe card to prevent the breakage of the connection of the body portion and the bump at the contact pressure of the probe by placing an elastic layer surrounding the bump between the body portion of the probe and the substrate.

In addition, the present invention is to provide a probe card that is formed separately from the tip and the body portion, the elastic layer surrounding the bump between the body portion and the substrate.

In order to solve the above technical problem, a method of manufacturing a probe card according to an aspect of the present invention includes: a) a first patterned pattern to exclude a bump area communicating with an upper surface terminal of the substrate connected to a wiring part in a substrate; Forming a photoresist layer; b) filling the bump area with a conductive material to form a bump; c) forming an elastic layer surrounding the bumps; d) forming a patterned second photoresist layer on the elastic layer to exclude a body region extending from the bump in at least one direction; e) filling the body region with a conductive material to form a body portion; f) forming a trench on the sacrificial substrate; g) filling the trench with a conductive material to form a tip; And h) bonding the tip portion to the body portion.

The elastic layer may be formed by applying a polymer.

The step c) may include forming the elastic layer on the substrate after removing the first photoresist layer.

The bump may be formed in multiple stages.

The step f) comprises the steps of forming an oxide film on the top surface of the sacrificial substrate; Forming a patterned mask layer to exclude trench regions corresponding to the trenches; Etching away the region corresponding to the trench region from the oxide layer using the mask layer; And forming the trench by etching the trench region at least once on the sacrificial substrate using the oxide film as a mask.

The method of manufacturing the probe card may further include forming a conductive metal layer by sputtering the conductive metal into the trench between the steps f) and g).

The method of manufacturing the probe card may further include increasing the depth of the trench by further stacking a patterned photoresist layer on the sacrificial substrate to exclude the trench between the steps f) and g). have.

The method of manufacturing the probe card may further include forming a contact layer by plating an upper portion of the tip of the probe with a conductive metal between the steps g) and h).

The conductive metal may be gold.

The probe tip portion and the probe body portion may be thermally bonded through the contact layer.

Probe card according to another feature of the present invention comprises a substrate having a top terminal; A bump in electrical contact with an upper terminal of the substrate and formed in a vertical direction from the upper terminal; An elastic layer formed to surround the bumps; A body part positioned on the elastic layer and electrically connected to the bump and one end thereof; A tip part formed separately from the body part and attached to the other end of the body part; And a contact layer contacting the body portion and the tip portion.

The elastic layer may be made of a polymer.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the method of manufacturing a probe card according to an embodiment of the present invention, after forming a bump of a probe (or an electrical contact element) on a substrate, an elastic layer surrounding the bump is formed, and a body part is formed on the bump and the elastic layer. And forming a tip portion of the probe on a separate sacrificial substrate, and then contacting the tip portion of the probe formed on the sacrificial substrate with a body formed on the substrate, and then removing the sacrificial substrate.

Hereinafter, a method of manufacturing a probe card according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5.

First, a method of forming a first bump on a substrate in a method of manufacturing a probe card according to an embodiment of the present invention will be described with reference to FIGS. 1A to 1G.

As shown in FIG. 1A, a silicon substrate or a multilayer ceramic substrate is chemically washed and prepared as the substrate 100. The substrate 100 is connected to one end of the wiring unit 151 and the wiring unit 151 therein and is connected to the other end of the upper terminal 152 and the wiring unit 151 attached to the upper surface of the substrate 100. There is no particular limitation as long as the lower surface terminal 153 attached to the lower surface of the substrate 100 is formed. Preferably, a space transformer that is made of a ceramic material and is commercially available may be used.

The metal film 101 is formed on the lower portion of the substrate 100 prepared as shown in FIG. 1B. The metal film 101 may be formed by applying a metal such as titanium or copper by chemical vapor deposition (CVD) or sputtering, but the formation method is not particularly limited. However, in the present embodiment was formed by sequentially applying titanium and copper by the sputtering method.

 The metal film 101 is used as an electrode in a plating process for bump formation and a body portion (hereinafter, also referred to as a 'beam portion') formation process.

Thereafter, as shown in FIG. 1C, the first photoresist layer 102 is formed by applying a photosensitive liquid to the upper surface of the substrate 100. The first photoresist layer 102 thus formed prevents metal from being plated on the upper surface of the substrate 100 in a later plating process.

Next, as shown in FIG. 1D, the metal film 101 on the lower surface of the substrate 100 is plated with a conductive metal to form a metal plating layer 103. In this case, copper is preferably used as the conductive metal. The metal plating layer 103 is used as an electrode together with the metal film 101 in a plating process for bump formation and a body portion (hereinafter, also referred to as a 'beam portion') process.

Next, the first photoresist layer 102 on the upper surface of the substrate 100 is etched and removed, and a photoresist is applied on the metal plating layer 103 on the lower surface of the substrate 100, as shown in FIG. 1E. 2 photoresist layer 104 is formed. The second photoresist layer 104 protects the metal plating layer 103 in a later process.

In this case, the etching solution used may be an etching solution which is commonly used to etch away the photoresist layer, preferably an alkaline etching solution such as acetone.

Next, as shown in FIG. 1F, a photoresist is applied to the upper surface of the substrate 100, and then patterned to expose the upper terminal 152 of the substrate 100 to form a third photoresist layer 105. The thickness of the third photoresist layer 105 corresponds to the height or length of the first bump to be described later, and may be appropriately set according to the object of the invention.

Thereafter, as shown in FIG. 1G, the patterned portion of the third photoresist layer 105 is filled with a conductive metal by a plating method using the metal film 101 and the metal plating layer 103 as electrodes. The first bump 106 is formed. After formation of the first bumps 106, the protruding portions may be ground by chemical mechanical polishing (CMP) or the like. At this time, the thickness of the first bump 106 may be adjusted again to a predetermined thickness. The shape of the first bump 106 is not particularly limited.

Next, when the thickness of the first bump 106 is not sufficient, the second bump may be further formed on the first bump.

Hereinafter, a method of forming a second bump on the first bump 106 in the method of manufacturing a probe card according to an embodiment of the present invention will be described with reference to FIGS. 2A and 2B.

First, as shown in FIG. 2A, a photoresist is applied to the upper surfaces of the third photoresist layer 105 and the first bump 106 of the substrate 100 and patterned to expose the first metal bump 106. The photoresist layer 107 is formed.

Thereafter, as shown in FIG. 2B, the patterned portion of the fourth photoresist layer 107 is filled with a conductive metal by a plating method using the metal film 101 and the metal plating layer 103 as electrodes. A second bump 108 is directly formed on the first bump 106.

The first bump 106 and the second bump 108 formed as described above are electrically connected to the upper terminal 152 of the substrate 100 and the wiring unit 151 connected to the upper terminal 152.

In this case, as the conductive metal used to form the first bumps 106 and the second bumps 108, a metal having excellent elasticity and conductivity is used. Preferably, nickel or nickel alloys, specifically nickel cobalt alloys or nickel iron alloys are used. This is preferably used.

Next, a method of forming an elastic layer in the method of manufacturing a probe card according to an embodiment of the present invention will be described with reference to FIGS. 3A to 3C.

First, as shown in FIG. 3A, the third photoresist layer 105 and the fourth photoresist layer 107 are etched away with an etching solution, and the elastic layer 109 is disposed above the height of the second bump 108. ). The elastic layer 109 may be formed by applying a polymer to the substrate 100. In the embodiment of the present invention, the polymer is not particularly limited as long as it can provide elastic force. Preferably, a polymer having a low coefficient of thermal expansion and having a non-conductive property is used.

Next, as shown in FIG. 3B, the elastic layer 109 is polished and ground to expose the second bumps 108.

As shown in FIG. 3C, only the elastic layer 109 is selectively etched and removed by several μm to protrude the second bump 108 by several μm from the elastic layer 109. The etching method is not particularly limited, but a dry etching method using D-RIE is preferably used.

Next, a method of forming the body portion of the probe of the probe card manufacturing method according to an embodiment of the present invention with reference to Figures 4a to 4f.

First, as shown in FIG. 4A, the conductive thin film 111 is formed of a conductive metal on the second bump 108 and the elastic layer 109. At this time, titanium or copper is preferably used as the conductive metal. In the present invention, the conductive thin film 111 may be formed by applying a metal such as titanium or copper by chemical vapor deposition (CVD) or sputtering, but the formation method is not particularly limited. However, in this embodiment, titanium and copper were sequentially applied by the sputtering method.

Next, as shown in FIG. 4B, the conductive thin film 111 formed on the second bump 108 is ground by chemical mechanical polishing (CMP) or the like to expose the second bump 108.

Thereafter, as illustrated in FIG. 4C, a rod-shaped region including the photoresist on the conductive thin film 111 and the second bump 108 on the upper surface of the substrate 100 and including the second bump 108 may be formed. Patterning so as to be exposed to form a fifth photoresist layer 112. This rod-shaped area is later used as a mold for the body or beam of the probe. The thickness of the fifth photoresist layer 112 corresponds to the height or the length of the body portion of the probe to be described later, and may be appropriately set according to the object of the invention. In the present embodiment, the body portion of the probe has a rod shape, but the shape of the body portion of the probe is not limited thereto.

Next, as shown in FIG. 4D, by using the metal film 101 and the metal plating layer 103 as electrodes, the metal mold patterned in the fifth photoresist layer 112 is filled with a conductive metal by a plating method. The body portion 113 is formed. As the conductive metal, the same metal as the bump is preferably used, and a nickel alloy is used in this embodiment.

Thereafter, as shown in FIG. 4F, the portion of the conductive metal filled in the mold protruding out of the fifth photoresist layer 112 is ground by chemical mechanical polishing (CMP) or the like. At this time, the thickness of the body portion 113 can be adjusted again to a predetermined thickness.

Thereafter, as shown in FIG. 4F, the bonding material 114 is applied to an area of the upper portion of the body portion 113 to be joined with the tip portion of the probe later. This bonding material 114 preferably uses Au paste, and the application of the bonding material 114 is performed using a screen printer.

Next, a method of forming a probe tip portion on a sacrificial substrate in the method of manufacturing a probe card according to an embodiment of the present invention will be described with reference to FIGS. 5A to 5H.

First, as shown in FIG. 5A, the sacrificial substrate 200 is prepared, and an oxide film 221 is formed on the top and bottom surfaces of the prepared sacrificial substrate 200. As the sacrificial substrate 200, a silicon substrate or a laminated ceramic substrate is preferably used.

Next, as can be seen in Figure 5b, by applying a photosensitive liquid on the upper surface of the sacrificial substrate 200 to form a seventh photoresist layer to expose a predetermined area for the tip portion of the probe to the seventh photoresist layer Patterning to form the first mask layer 222.

Thereafter, as shown in FIG. 5C, the oxide layer 221 corresponding to a predetermined region for the tip portion of the probe is etched away using the first mask layer 222. In this case, the etching method of the oxide film 221 is not particularly limited as long as it is commonly used, and generally, an etching solution such as a dry etching method such as active ion etching or a buffer oxide etchant may be used. Use the wet etching method used.

Thereafter, as shown in FIG. 5D, the first mask layer 222 is etched away, and the sacrificial substrate 200 is etched using the oxide film 221 having a predetermined region etched away for the tip portion of the probe as a mask. To form a trench 223 for the probe tip. In this case, KOH may be used as an etching solution, and the depth or shape of the trench 223 may be appropriately adjusted by adjusting the etching time. The bottom bottom of the trench 223 thus formed corresponds to the top of the probe tip.

Thereafter, as shown in FIG. 5E, after the oxide film 221 is etched away, the conductive metal is sputtered to form the conductive metal layer 224 on the trench 223 and the sacrificial substrate 200. In an embodiment of the present invention, titanium and copper are sequentially sputtered to form the conductive metal layer 224.

Thereafter, as shown in FIG. 5F, a photoresist is applied over the conductive metal layer 224 and patterned to expose the trench 223 region to form an eighth photoresist layer 225.

The thickness of the eighth photoresist layer 225 may be used to control the depth of the trench 223. Specifically, as the thickness of the eighth photoresist layer 225 becomes thicker, the depth of the trench 223 may be increased. This results in an increase in the length of the probe tip. Therefore, the length of the probe tip portion can be adjusted to the thickness of the eighth photoresist layer 225.

Next, as illustrated in FIG. 5G, the probe tip portion 226 is formed by filling the inner region of the trench 223 with the conductive metal using the plating method using the conductive metal layer 224 as an electrode. As such a conductive metal, a nickel alloy like the probe body 113 is preferably used.

In this case, as shown in Fig. 5H, the protruding portion is ground by chemical mechanical polishing (CMP) or the like.

Next, as shown in FIG. 5I, the contact layer 127 is formed by plating the upper portion of the probe tip portion 226 with the conductive metal using the conductive metal layer 224 as an electrode. In this case, gold is preferably used as the conductive metal.

Thereafter, the sacrificial substrate 200 having the probe tip portion 226 formed therein by FIGS. 5A to 5I is aligned on the substrate 100 on which the probe body portion 113 is formed by FIGS. 4A to 4F. At this time, the positions of the sacrificial substrate 200 and the substrate 100 are aligned such that the probe tip portion 226 is located in a corresponding region among the regions of the probe body portion 113.

The sacrificial substrate 200 and the substrate 100 are attached to each other so that the probe tip 226 contacts the corresponding area of the probe body 113, such that the contact layer 127 and the probe of the probe tip 226 are attached. After the areas where the bonding material 114 of the body portion 113 is coated are brought into contact with each other, heat and pressure are applied to the bonding material 114 to thermally bond the probe tip portion 226 and the probe body portion 113 to each other. . The thermal bonding method may use a flip chip bond (FCB) or anion bonding method.

As such, when the probe tip portion 226 and the probe body portion 113 are attached to each other, the sacrificial substrate 200, the eighth photoresist layer 225, the conductive thin film 111, and the like are all removed by etching. A probe card with a probe as described above is formed. In this case, the etching of the conductive thin film 111 must be completely performed at least between the plurality of probe body portions 113 adjacent to each other so that the plurality of probe body portions 113 are not electrically shorted to each other. In this case, the conductive thin film 111 may be etched away enough to electrically separate the plurality of adjacent probe body portions 113, and the conductive thin film 111 between the probe body 113 and the elastic layer 109 may be removed. ) Does not have to be etched away.

As described above, the probe card manufactured by the method of manufacturing the probe card of the present invention includes a plurality of probes simultaneously formed on the substrate 100 through a MEMS process.

Specifically, the probe card according to an embodiment of the present invention includes a bump 108 electrically connected to the substrate 100 and the upper terminal 152 of the substrate 100 and formed in a vertical direction from the upper terminal 152; An elastic layer formed to surround the bumps; A body portion 113 positioned above the elastic layer and electrically connected to the bump 108 and one end thereof; A tip portion 226 formed separately from the body portion 113 and attached to the other end of the body portion 113; And a contact layer 127 for contacting the body portion 113 and the tip portion 226.

 As described in detail above, according to the method of manufacturing a probe card of the present invention, bumps and body parts of bumps, body parts, and tips, which are components of the probe, are directly formed on a substrate, but the tip part is formed using a sacrificial substrate. Formed separately, the tip is formed on the body portion to produce a probe card. Therefore, in the method of manufacturing the probe card of the present invention, it is not necessary to simultaneously form the body portion and the tip portion of the probe by the metal plating method as in the conventional method, since the plating process for forming the body portion is not performed for a long time, The uniformity of the formed body portion is excellent. Thus, the polishing process for the body portion does not need to be performed for a long time.

As described above, according to the method of manufacturing a probe card of the present invention, the plating process and the polishing process time are shorter when forming the probe body portion, so that the overall process time is improved, and voids are less generated when forming the probe tip portion, and the probe tip portion is formed by the polishing process. Since there is no breakage of the connection part of the body part, the process yield can be greatly improved.

In addition, according to the method for manufacturing a probe card of the present invention, by forming an elastic layer around the bumps of the probe and forming a body portion connected to the bumps on the elastic layer, the probe contacts the contact pads of the semiconductor element and the like to form the body portion. When pressure is applied, the pressure is absorbed to some extent in the elastic layer to minimize the force applied to the connection portion between the body portion and the bump to prevent damage to the body portion and the bump.

In addition, according to the manufacturing method of the probe card of the present invention, the probe tip portion can be easily produced in a short time by one metal plating process through the sacrificial substrate separately from the body portion. In addition, the shape of the tip portion of the probe tip portion can be manufactured in various ways according to the purpose, so that the scrub mark of the probe tip portion can be made smoothly with respect to the contact pad, and the generation of voids when the probe tip portion is formed by metal plating is a conventional technique. Significantly lower than.

In addition, since the probe tip portion is formed separately, an accurate mask may be formed through an exposure process and an etching process for fabricating the probe tip, and thus a plurality of probe tips may be uniformly manufactured in the form of a mask.

In addition, by forming a trench for the probe tip portion, the wet etching process can be used to easily control the size and depth of the trench according to the purpose by adjusting the process time, and accordingly fine probes can be formed more precisely. It is possible to cope with (fine pitch).

In addition, the probe card manufactured by the method of manufacturing a probe card of the present invention supplements the elastic force of the body portion with the elastic force of the elastic layer, thereby preventing damage to the connection portion of the bump and the body portion, and the damage is caused by the tip portion of the probe or the tip portion and the body portion. Since it occurs only at the connection portion, there is an advantage that can be easily repaired by repairing only the tip or the body.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the technical idea of the present invention, and it is obvious that the present invention belongs to the appended claims. Do.

Claims (12)

a) forming a first photoresist layer patterned to exclude a bump area communicating with a top terminal of the substrate connected to a wiring part in the substrate; b) filling the bump area with a conductive material to form a bump; c) forming an elastic layer surrounding the bumps; d) forming a patterned second photoresist layer on the elastic layer to exclude a body region extending from the bump in at least one direction; e) filling the body region with a conductive material to form a body portion; f) forming a trench on the sacrificial substrate; g) filling the trench with a conductive material to form a tip; And h) bonding the tip to the body; Method of manufacturing a probe card comprising a. The method of claim 1, The elastic layer is The method of manufacturing the probe card, characterized in that formed by applying a polymer. The method of claim 1, Step c) is After removing the first photoresist layer, forming the elastic layer on the substrate. The method of claim 1, And forming the bumps in multiple stages. The method of claim 1, Step f) is Forming an oxide film on an upper surface of the sacrificial substrate; Forming a patterned mask layer to exclude trench regions corresponding to the trenches; Etching away the region corresponding to the trench region from the oxide layer using the mask layer; And Forming the trench by etching the trench region at least once on the sacrificial substrate using the oxide film as a mask; Method for producing the probe card, characterized in that it comprises a. The method of claim 1, Between the steps f) and g) Sputtering the conductive metal into the trench to form a conductive metal layer; Method for producing the probe card, characterized in that it further comprises. The method of claim 1, Between the steps f) and g) Further stacking a patterned photoresist layer to exclude the trench on the sacrificial substrate to increase the depth of the trench; Method for producing the probe card, characterized in that it further comprises. The method of claim 1, Between steps g) and h) Plating an upper portion of the tip of the probe with a conductive metal to form a contact layer; Method for producing the probe card, characterized in that it further comprises. The method of claim 8, And the conductive metal is gold. The method of claim 8, And the probe tip portion and the probe body portion are thermally bonded through the contact layer. A substrate having a top terminal; A bump in electrical contact with an upper terminal of the substrate and formed in a vertical direction from the upper terminal; An elastic layer formed to surround the bumps; A body part positioned on the elastic layer and electrically connected to the bump and one end thereof; A tip part formed separately from the body part and attached to the other end of the body part; And A contact layer contacting the body portion and the tip portion; Probe card comprising a. The method of claim 11, The elastic layer is The probe card, characterized in that made of a polymer.

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