PROBE SHEET WITH CONTACT TIP ON STACKED MULTI-LAYER AND METHOD OF MANUFACTURING THE SAME

Abstract

Disclosed are a probe sheet with a multi-layer contact tip and a method of manufacturing the same capable of improving the design freedom of a contact tip formed on a probe sheet of a probe card for testing a semiconductor device to come in contact with a pad of the semiconductor device. According to the present invention, the design freedom of a contact tip formed on a probe sheet of a probe card for testing a semiconductor device to come in contact with a pad of the semiconductor device can be improved, and since the shape of a contact surface of a contact tip is maintained the same and contact resistance is maintained in an allowable range even when a protective layer coated on the contact tip to increase durability of the contact tip is worn, test reliability of the probe card can be improved.

Claims

1. A probe sheet with a multi-layer contact tip, the probe sheet comprising: a seed layer (103) formed on an upper portion of a polyimide layer (102) of a base substrate (101); a first polyimide layer (104) formed by laminating a polyimide film on an upper portion of the seed layer (103) in a vacuum atmosphere and having an etching hole (105) formed on a film surface; a ground line layer (106) formed by forming a titanium/copper (Ti/Cu) layer on the etching hole (105) using high-temperature sputtering and forming a Cu layer with a predetermined thickness thereon using electroplating; a second polyimide layer (107) formed by laminating a polyimide film on upper portions of the first polyimide layer (104) and the ground line layer (106) in a vacuum atmosphere and having an etching hole (108) and a connecting hole (109) formed on a film surface; a circuit line layer (110) formed by forming a Ti/Cu layer on the etching hole (108) using high-temperature sputtering and forming a Cu layer with a predetermined thickness thereon using electroplating and connected to the ground line layer (106) through the connecting hole (109); a third polyimide layer (111) formed by laminating a polyimide film on upper portions of the second polyimide layer (107) and the circuit line layer (110) in a vacuum atmosphere and having an etching hole (112) and a connecting hole (113) formed on a film surface; a base bump layer (114) formed by forming a Ti/Cu layer on the etching hole (112) using high-temperature sputtering and forming a nickel-cobalt (NiCo) alloy layer with a predetermined thickness thereon using electroplating and molding processes; a first contact tip layer (116) formed by forming a NiCo alloy layer with a predetermined thickness on an upper portion of the base bump layer (114); a second contact tip layer (118) formed by forming a NiCo alloy layer with a predetermined thickness on an upper portion of the first contact tip layer (116); and a protective layer (120) formed by etching a portion around the second contact tip layer (118) exposed using an etching groove for coating the second contact tip layer (118) and coating an outer surface of the second contact tip layer (118) with rhodium using electroplating.

2. The probe sheet of claim 1, wherein: a cross-sectional area of the second contact tip layer (118) is formed smaller than a cross-sectional area of the first contact tip layer (116); and the cross-sectional area of the first contact tip layer (116) is formed smaller than a cross-sectional area of the base bump layer (114).

3. The probe sheet of claim 2, wherein the first and second contact tip layers (116) (118) are formed in the shape of a quadrangular column.

4. A method of manufacturing a probe sheet with a multi-layer contact tip, the method comprising: (a) forming a seed layer (103) including a titanium/copper (Ti/Cu) layer (103-1) and a Cu layer (103-2) on an upper portion of a polyimide layer (102) of a base substrate (101); (b) laminating a polyimide film on an upper portion of the seed layer (103), which is formed in step (a), in a vacuum atmosphere to form a first polyimide layer (104) and forming an etching hole (105) on a film surface thereof; (c) forming a ground line layer (106) by a process of forming a Ti/Cu layer on the etching hole (105) using high-temperature sputtering and forming a Cu layer with a predetermined thickness thereon using electroplating; (d) laminating a polyimide film on upper portions of the first polyimide layer (104) and the ground line layer (106) in a vacuum atmosphere to form a second polyimide layer (107) and forming an etching hole (108) and a connecting hole (109) on a film surface thereof; (e) forming a circuit line layer (110) by a process of forming a Ti/Cu layer on the etching hole (108) using high-temperature sputtering and forming a Cu layer with a predetermined thickness thereon using electroplating; (f) laminating a polyimide film on upper portions of the second polyimide layer (107) and the circuit line layer (110) in a vacuum atmosphere to form a third polyimide layer (111) and forming an etching hole (112) and a connecting hole (113) on a film surface thereof; (g) forming a base bump layer (114) by a process of forming a Ti/Cu layer on the etching hole (112) using high-temperature sputtering and forming a nickel-cobalt (NiCo) alloy layer with a predetermined thickness thereon using electroplating and molding processes; (h) forming a first contact tip layer (116) as a NiCo alloy layer with a predetermined thickness on an upper portion of the base bump layer (114); (i) forming a second contact tip layer (118) as a NiCo alloy layer with a predetermined thickness on an upper portion of the first contact tip layer (116); (j) forming a protective layer (120) by etching a portion around the second contact tip layer (118) exposed using an etching groove for coating the second contact tip layer (118) and coating an outer surface of the second contact tip layer (118) with rhodium using electroplating; and (k) removing the base substrate (101), the polyimide layer (102), and the seed layer (103) at the bottom using a laser.

Description

DESCRIPTION OF DRAWINGS

[0019] FIG. 1A is an image of a probe card to which a probe sheet with a multi-layer contact tip according to an embodiment of the present invention is coupled.

[0020] FIG. 1B is a cross-sectional view of the probe sheet with the multi-layer contact tip according to an embodiment of the present invention.

[0021] FIG. 1C is a flowchart for describing a method of manufacturing the probe sheet with the multi-layer contact tip according to an embodiment of the present invention.

[0022] FIGS. 2A to 2K are schematic views sequentially showing a process of manufacturing the probe sheet with the multi-layer contact tip according to an embodiment of the present invention.

[0023] FIG. 3 is an image of the multi-layer contact tip according to an embodiment of the present invention.

MODES OF THE INVENTION

[0024] Hereinafter, the present invention will be described by describing embodiments of the present invention with reference to the accompanying drawings. The same reference numerals presented in each drawing represent the same components. Also, in describing the present invention, when a detailed description of a relevant known function or configuration is determined as having the possibility of unnecessarily obscuring the gist of the present invention, the detailed description thereof will be omitted. Also, when a certain part is described as including a certain component, this means that the certain part may further include other components instead of excluding other components unless particularly described otherwise.

[0025] A probe card according to the present invention is connected to a testing apparatus and used to test a semiconductor device.

[0026] The probe card according to the present invention comes in contact with a pad of a semiconductor device through a multi-layer contact tip, which is formed on a probe sheet, and detects information of the semiconductor device. Here, the probe card may be mounted on an opening formed in a printed circuit board (PCB) and detect information of the semiconductor device. An opening may be formed in the PCB for a probe card to be mounted thereon, and a probe card may be mounted on the corresponding opening.

[0027] As illustrated in FIG. 1A, a probe sheet 100 according to an embodiment may be manufactured as a flexible substrate, for example, a flexible polyimide film, and installed on a support portion 10 of a probe card.

[0028] A multi-layer contact tip and an electric circuit pattern are formed on the probe sheet 100. The electric circuit pattern includes a ground line GND, a signal line SIG, a power line PWR, and the like.

[0029] Referring to FIGS. 1B and 1C, in the probe sheet 100 with a multi-layer contact tip according to an embodiment of the present invention, a ground line layer 106 may be formed on polyimide layers 104 and 107 (S100), a circuit line layer 110 may be formed on a polyimide layer 111 which is at an upper portion of the polyimide layers 104 and 107 (S200), and a multi-layer contact tip 121 formed at an upper portion of the polyimide layer 111 may be exposed (S300).

[0030] The circuit line layer 110 may form an electric circuit pattern such as a signal line SIG configured to transmit a test signal, a power line PWR configured to supply power, and a ground line GND. In an embodiment, a mesh type grounding conductor is formed as the ground line layer 106.

[0031] The multi-layer contact tip 121 may include a base bump layer 114 electrically connected to the circuit line layer 110 through a via-hole, first and second contact tip layers 116 and 118 sequentially formed on an upper portion of the base bump layer 114, and a protective layer 120 coated on an outer surface of the contact tip layer.

[0032] A method of manufacturing the probe sheet will be described with reference to FIGS. 2A to 2K.

[0033] As illustrated in FIG. 2A, a base substrate 101 is prepared. An insulating substrate made of ceramic, glass, or the like may be used as the base substrate 101. Here, a process of washing and drying a surface of the base substrate 101 to remove foreign matter or the like attached to the base substrate may be further included.

[0034] An upper portion of the base substrate 101 is coated with liquid polyimide, and high-temperature curing is performed to form a polyimide layer 102. For the high-temperature curing, drying and heat treatment are performed using hot air with an atmospheric temperature of 350? C. and a process time of 1 hour.

[0035] A seed layer 103 including a titanium/copper (Ti/Cu) layer 103-1 and a Cu layer 103-2 is sequentially formed on an upper portion of the polyimide layer 102. The Ti/Cu layer 103-1 is formed using high-temperature sputtering, the Cu layer 103-2 is formed with a predetermined thickness on an upper portion of the Ti/Cu layer 103-1 using electroplating, and then polishing is performed to smooth the surface.

[0036] A polyimide film (PI film) having a thickness of 12.5 ?m is laminated on an upper portion of the seed layer 103 in a vacuum atmosphere to form a polyimide layer 104.

[0037] In FIG. 2B, an upper portion of the polyimide layer 104 is removed using an etching solution to form an etching hole 105 that corresponds to the ground line pattern GND.

[0038] In FIGS. 2C and 2D, the ground line layer 106 that corresponds to the etching hole 105 is formed using a damascene process. In the ground line layer 106, a Ti/Cu layer is formed using high-temperature sputtering, and a Cu layer is formed with a predetermined thickness thereon using electroplating. The polyimide layer 107 is formed on upper portions of the polyimide layer 104 and the ground line layer 106. The formation of the polyimide layer 107 is performed by an adhesion process in which a PI film having a thickness of 25 ?m is laminated in a vacuum atmosphere. An etching hole 108 and a connecting hole 109 are formed at an upper portion of the polyimide layer 107. An upper portion of the polyimide layer 107 is removed using an etching solution to form the etching hole 108 that corresponds to a signal line pattern, and the connecting hole 109 is formed by a hole drilling process using a laser.

[0039] As illustrated in FIG. 2E, the circuit line layer 110 is formed. The circuit line layer 110 is formed by a process in which a Ti/Cu layer is formed using high-temperature sputtering, and a

[0040] Cu layer is formed with a predetermined thickness thereon using electroplating.

[0041] In FIG. 2F, the polyimide layer 111 is formed on upper portions of the polyimide layer 107 and the circuit line layer 110. The formation of the polyimide layer 111 is performed by an adhesion process in which a PI film having a thickness of 25 ?m is laminated in a vacuum atmosphere. An etching hole 112 and a connecting hole 113 are formed at an upper portion of the polyimide layer 111. The etching hole 112 is formed, and then the connecting hole 113 is formed.

[0042] An upper portion of the polyimide layer 111 is removed using an etching solution to form the etching hole 112 that corresponds to a contact tip pattern, and the connecting hole 113 is formed by a hole drilling process using a laser.

[0043] In FIG. 2G, the base bump layer 114 of the contact tip is formed. The formation of the base bump layer 114 includes performing etching on a photoresist film 115 along a base bump pattern, forming a Ti/Cu layer on the etched portion using high-temperature sputtering, forming a NiCo alloy layer having a predetermined thickness thereon using electroplating and molding processes, and performing a polishing process of smoothing the surface.

[0044] In FIG. 2H, the first contact tip layer 116 is formed. The formation of the first contact tip layer 116 includes performing etching on a photoresist film 117 along a first contact tip pattern, forming a NiCo alloy layer having a predetermined thickness on an upper portion of the base bump layer 114, which is exposed due to etching, using electroplating and molding processes, and then performing a polishing process of smoothing the surface. Here, a cross-sectional area of the first contact tip layer 116 is formed smaller than a cross-sectional area of the base bump layer 114.

[0045] In FIG. 2I, the second contact tip layer 118 is formed. The formation of the second contact tip layer 118 includes performing etching on a photoresist film 119 along a second contact tip pattern, forming a NiCo alloy layer having a predetermined thickness on an upper portion of the first contact tip layer 116, which is exposed due to etching, using electroplating and molding processes, and then performing a polishing process of smoothing the surface.

[0046] In FIG. 2J, the protective layer 120 is formed. The formation of the protective layer 120 includes forming an etching groove (recess) for coating, etching a portion around the second contact tip layer 118 exposed using the etching groove, and coating the protective layer 120 on an outer surface of the second contact tip layer 118 using electroplating. The protective layer 120 serves to coat and protect the outer surface of the second contact tip layer 118 and may be formed of a material having excellent durability. In an embodiment, the protective layer 120 is formed of rhodium that has high electrical conductivity and durability.

[0047] Lastly, as illustrated in FIG. 2K, the probe sheet to be applied to a probe card may be manufactured by removing the base substrate 101, the polyimide layer 102, and the seed layer 103 at the bottom using a laser and removing the photoresist films 115 and 117 at the top through a stripping process.

[0048] Referring to FIG. 3, the multi-layer contact tip 121 according to an embodiment of the present invention is formed by the first and second contact tip layers 116 and 118 with narrowing cross-sectional areas being formed in a stair shape on an upper portion of the base bump layer 114 and the protective layer 120 being coated on the second contact tip layer 118. The first contact tip layer 116 and the second contact tip layer 118 are formed in the shape of a quadrangular column, and the cross-sectional area of the second contact tip layer 118 is formed smaller than the cross-sectional area of the first contact tip layer 116.

[0049] According to an embodiment, by carrying out a performance test for various shapes of contact tips, a contact tip shape profile suitable for a semiconductor device to be tested can be easily obtained.

[0050] According to an embodiment, even when a multi-layer contact tip is worn and a length thereof is decreased during use of a probe card, a cross-sectional area of the contact tip formed in the shape of a quadrangular column can be maintained constant. Such a wear characteristic of the contact tip can be confirmed through a constant shape of contact marks formed on a semiconductor device pressed by the contact tip through repeated tests using the probe card.

[0051] Since the cross-sectional area of the contact tip worn in this way is constant, contact resistance of the contact tip that is allowed for product design can be continuously satisfied, and thus test reliability of the probe card can be improved.

[0052] According to an embodiment, since a process of forming a coating layer on a surface of a contact tip using electroplating is applied, even when a thickness of rhodium is different according to various requirements of a target to be tested, rhodium can be formed with a desired thickness by changing process conditions.

[0053] The above-given description of the present invention is only illustrative, and those of ordinary skill in the art to which the present invention pertains should understand that the present invention can be easily modified to other specific forms without changing the technical spirit or essential features of the present invention.

Industrial Applicability

[0054] Electrical characteristics of semiconductor devices such as a radio frequency (RF) communication device can be stably tested using a probe card on which a probe sheet with a multi-layer contact tip according to the present invention is mounted.