TW201400819A - Probe structure and method for fabricating thin film probe - Google Patents

Abstract

A probe structure and a method for fabricating a thin film probe are provided. The probe structure comprises a thin film probe. The thin film probe includes an insulating film and conductive bars. The insulating film has a first film surface and a second film surface opposite to the first film surface, and has a first film sidewall and a second film sidewall opposite to the first film sidewall. The insulating film is made of a flexible material. The conductive bars are disposed on the first film surface of the insulating film. Each of the conductive bars has a first conductive end portion and a second conductive end portion opposite to the first conductive end portion. The first conductive end portion of the each of the conductive bars is extended beyond the first film sidewall of the insulating film. The conductive bars separated from each other are arranged in a fan out shape so that a pitch of the first conductive end portions of the conductive bars is smaller than a pitch of the second conductive end portions of the conductive bars.

Description

Probe structure and method for manufacturing thin film probe

The present invention relates to a probe structure and a method of manufacturing a membrane probe, and more particularly to a probe structure having a membrane probe.

The trend of semiconductor integrated circuit wafers is toward miniaturization, in which the unit density of components is becoming higher and higher. Therefore, the size and spacing of signal input/output terminals such as bumps and pads of semiconductor integrated circuit chips will increase. The smaller the size, the higher the demand for micro-probes for testing wafers.

The semiconductor integrated circuit chip needs to pass an electrical tester to confirm the circuit characteristics before shipment. In order to cope with the small size and spacing of the contact terminals and improve the efficiency of testing the component array, the electrical tester must use a fine probe array as the medium for electrical contact with the device under test, and with a space converter to probe the probe. The array is electrically connected to a circuit board having a larger size and a larger pitch at the contact end.

However, it is difficult to make the contact end spacing in accordance with the current material to be tested or the probe array specifications due to the limitations of the materials and processes of the general space converter. Therefore, techniques to overcome the current problems are necessary.

The present invention relates to a probe structure and a method of manufacturing a thin film probe. Thin film probes are simple to manufacture and low in cost, and thin film probes are suitable for testing miniaturized semiconductor structures.

According to an embodiment of the invention, a probe structure is provided. The probe structure includes a thin film probe. The thin film probe includes an insulating film and a plurality of conductive strips. The insulating film has a first film surface and a second film surface, and has a first film side and a second film side. The insulating film is made of a flexible material. A conductive strip is disposed on the surface of the first film of the insulating film. The conductive strips each have a first conductive end and a second conductive end. The first conductive end of the conductive strip extends beyond the first film side of the insulating film. The mutually separated conductive strips are arranged in a fan shape such that the pitch of the first conductive ends of the conductive strips is smaller than the pitch of the second conductive ends.

According to another embodiment of the present invention, a method of fabricating a thin film probe is provided. The manufacturing method includes the following steps. A conductive layer is formed on a layer of insulating material. The conductive layer is patterned to form a plurality of conductive strips. The conductive strips each have a first conductive end and a second conductive end. The mutually separated conductive strips are arranged in a fan shape such that the pitch of the first conductive ends of the conductive strips is smaller than the pitch of the second conductive ends. A portion of the insulating material layer is removed to form an insulating film. The insulating film has a first film side and a second film side. Each of the first conductive ends of the conductive strip extends beyond the first film side of the insulating film.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the preferred embodiment will be described in detail with reference to the accompanying drawings.

1 is a top view of a membrane probe 102 in accordance with an embodiment. The membrane probe 102 includes an insulating film 104 and a plurality of conductive strips 106.

Referring to FIG. 1, the insulating film 104 has opposing first film side edges 108 and second film side edges 110, and has opposing first film surface 112 and second film surface 114. The insulating film 104 is made of a flexible material, and includes a polymer material commonly used in a packaging process, such as polyimide (PI), polydimethylsiloxane (PDMS), and acrylic resin (Acrylate). Or benzocyclobutene (BCB).

A plurality of conductive strips 106 are disposed on the first film surface 112 of the insulating film 104. The conductive strips 106 each have opposing first conductive ends 116 and second conductive ends 118. In an embodiment, the first conductive end 116 extends beyond the first film side 108 of the insulating film 104. The conductive strips 106 which are separated from each other are arranged in a fan shape such that the distance D1 of the first conductive ends 116 of the conductive strips 106 on the same insulating film 104 is smaller than the distance D2 of the second conductive ends 118. In an embodiment, the first conductive end 116 of the conductive strip 106 can serve as a needle in contact with the device to be tested, and the pitch D1 is less than 50 μm. In an embodiment, the pitch D1 is, for example, between 20 μm and 50 μm, which is very The small size can be adapted to the development of miniaturized electronic components such as semiconductor integrated circuit chips (not shown), and the pitch between input/output terminals such as pads or bumps tends to be smaller.

Referring to FIG. 1 , the second conductive end 118 of the conductive strip 106 can be in contact with the contact end of other components of the electrical tester, and the pitch D2 is greater than 50 μm, for example, greater than 100 μm, and can be matched with other components of the current general electrical tester. The range of spacing of the contact ends. The thin film probe 102 of the embodiment thus allows the general electrical tester to continue to be used in the trend of miniaturization of components to be tested, such as semiconductor integrated circuit chips (not shown). Although Figure 1 The width of the first conductive end 116 of the conductive strip 106 is smaller than the width W2 of the second conductive end 118. However, the embodiment is not limited thereto. In other embodiments, the conductive strip 106 may also be designed to be substantially uniform. Width (not shown). The material of the conductive strip 106 may include a metal such as nickel, gold, copper, tungsten, titanium, palladium or an alloy thereof.

Referring to FIG. 1 , in an embodiment, the second conductive end 118 of the conductive strip 106 optionally has conductive bumps 120 , and the conductive bumps 120 may be located on the second film side 110 of the insulating film 104 . on. The lower surface 122 of the conductive bump 120 is not limited to the second film side 110 substantially aligned with the insulating film 104 as shown in FIG. 1, and in some embodiments (not shown), the lower surface of the conductive bump 120 122 (which may also be regarded as the interface between the conductive strips 106 and the conductive bumps 120) is about 10 μm lower than the second film side edges 110 of the insulating film 104, and the upper surface 124 of the conductive bumps 120 is higher than the insulating film 104. The second film side 110 is about 30 μm. For example, the material of the conductive bumps 120 includes nickel, tin, or an alloy thereof, or other suitable materials.

As shown in FIG. 1, the insulating film 104 may define perforations 126, 128, 130, 132, 134, 136. For example, the perforations 126, 128, 130, 132 are sized larger than the perforations 134, 136. In some embodiments, the perforations 126, 128, 130, 132 have a diameter greater than 200 [mu]m, including 200 [mu]m to 300 [mu]m, such as 115 [mu]m. The diameter of the perforations 134, 136 is less than 20 μm, such as 1.45 μm. The embodiment is not limited to the circular perforations 126, 128, 130, 132, 134, 136 as shown in Fig. 1 and the symmetric configuration design, and other shapes of perforations and other configuration designs may be suitably used depending on actual needs.

2 is a perspective view of a probe structure 238 according to an embodiment. The probe structure 238 includes a plurality of thin film probes 202, wherein the thin film probe 202 shown in FIG. 2 is similar to the thin film probe 102 shown in FIG. 1, the difference is only in the first The thin film probe 202 shown in Fig. 2 omits the conductive bump 120 shown in Fig. 1. In other embodiments, the probe structure 238 can use the membrane probe 102 as shown in FIG.

As shown in FIG. 2, the probe structure 238 includes a plurality of positioning members 240 configured to pass through the through holes 226, 228, 230, 232, 234, 236 defined by the insulating film 204 to position the overlapping film. The probe film 202, the first film surface 212 of one of the film probes 202 faces the second film surface 214 of the other of the film probes 202, and is disposed on the different insulating film 204 and arranged in a fan shape. The conductive strips 206 are separated from each other.

Referring to FIG. 2, in some embodiments, the thickness T1 of the insulating film 204 is between 1 μm and 50 μm, for example, between 1 μm and 12.5 μm or about 25 μm, and the thickness T2 of the conductive strip 206 is less than 30 μm, for example, 0.1 μm to 10 μm or about 25 μm. The spacing D3 of the conductive strips 206 on the different insulating films 204 (or their first conductive ends 216, shown in FIG. 2) is less than 50 μm, and further, the conductive strips 206 on the same insulating film 204 (or their first conductive layers) The pitch D1 of the end 216) is less than 50 μm. In one embodiment, the pitch D1 is, for example, 20 μm to 50 μm. In other words, the pitches D1 and D3 of the first conductive terminals 216 of the array of conductive strips 206 are very small. Therefore, the probe structure 238 of the embodiment can be applied to test a device to be tested having a high-density array structure, such as a semiconductor integrated circuit chip in a semiconductor package. Furthermore, the probe structure 238 of the embodiment can be used in one or more devices. Contact contact for testing, thus reducing test time and shipping speed. In addition, the manner in which the thin film probes 202 are assembled to form the probe structure 238 is simple, so that the design of the probe structure 238 can be arbitrarily changed according to actual needs, the use is versatile, and each conductive strip in the probe structure 238 can be accurately controlled. The difference in the height difference between the first conductive end 216 and the second conductive end 218 of the 206 is small, and the flatness of the contact point improves the efficiency of electrical contact with other components such as the device to be tested, and also avoids the unevenness of the contact point. A large pressure is applied to achieve the problem of probe breakage and damage caused by the overall contact, and the service life and reliability of the probe structure 238 are improved.

Referring to FIG. 3, a cross-sectional view of the probe structure 238 along line AB of FIG. 2 is shown. As shown in FIG. 3, the positioning member 240 is disposed through the through holes 226, 230 defined by the insulating film 204, the first film surface 212 facing the second film surface 214, and the conductive strips on the different insulating film 204. The 206 series are separated from each other.

Referring to FIG. 4, a conductive strip 206 of the probe structure 238 of FIGS. 2 and 3 according to an embodiment is illustrated, and other elements of the probe structure 238 are not shown.

5 to 9 illustrate a method of fabricating a thin film probe according to an embodiment.

Referring to FIG. 5, the insulating material layer 342 is disposed on the support substrate 344. In one embodiment, the insulating material layer 342 is composed of a flexible material, and the supporting substrate 344 is made of a hard material such as glass to support the insulating material layer 342 for subsequent steps. For example, the insulating material layer 342 may be a layer of polyimine material remaining after removing the rolled copper foil formed on the layer of polyimine (PI) material. In one embodiment, the heat removal type is utilized A thermal release tape (not shown) attaches the insulating material layer 342 to the support substrate 344.

Referring to FIG. 6, a conductive layer 346 is formed on the insulating material layer 342. In one embodiment, the conductive layer 346 is formed by thermal evaporation. The conductive layer 346 may have a thickness of 0.1 μm to 0.2 μm, for example, 0.2 μm.

Referring to FIG. 7, the patterned conductive layer 346 forms a conductive strip 306. Conductive strip 306 has opposing first conductive ends 316 and second conductive ends 318. The electrically conductive strips 306 that are separated from one another are in a fan configuration such that the spacing D1 of the first electrically conductive ends 316 is less than the spacing D2 of the second electrically conductive ends 318. In one embodiment, the method for forming the conductive strip 306 includes applying a photoresist layer (not shown) such as AZ-4620 photoresist to the conductive layer 346 (FIG. 6), and then exposing and developing the photoresist layer. To form a patterned photoresist layer (not shown), the conductive layer 346 (FIG. 6) exposed by the patterned photoresist layer is removed to form a conductive strip 306 (FIG. 7), and then the pattern is removed. Photoresist layer. In some embodiments, after the patterning step, an electroplating process may also be performed to make the conductive strip 306 include a plating layer of, for example, 10 μm to 20 μm. For example, the electroplated conductive strip 306 has a thickness T2 of 15 μm.

Referring to Fig. 8, then, for example, the support substrate 344 (Fig. 7) is removed, and a portion of the insulating material layer 342 (Fig. 7) is removed to form an insulating film 304 as shown in Fig. 8. The insulating film 304 has opposing first film side edges 308 and second film side edges 310. The first conductive end 316 of the conductive strip 306 extends beyond the first film side 308 of the insulating film 304. The second film side 310 of the insulating film 304 is adjacent to the second conductive end 318 of the conductive strip 306.

Referring to Figure 9, a portion of the insulating film 304 is removed to define a plurality of Perforations 326, 328, 330, 332, 334, 336. The embodiment is not limited to the first order in which the first film side 308 (Fig. 8) and the second film side 310 are defined to define the perforations 326, 328, 330, 332, 334, 336 (Fig. 9). It is also possible to define the order of the first film side 308 (Fig. 8) and the second film side 310 by first defining the perforations 326, 328, 330, 332, 334, 336. In an embodiment, the removing step may be performed by a laser method. For example, the laser power system of the first film side 308 and the second film side 310 (Fig. 8) of the insulating film 304 is cut less than the definition. The laser power of the perforations 326, 328, 330, 332, 334, 336 (Fig. 9). The laser used can be Nd-YAG (wavelength 355 nm) or excimer laser (wavelength 248 nm), which is highly efficient and good in material removal. In other embodiments, the removal step can also be performed using other suitable methods, such as using a processing machine. In some embodiments, after defining a film side 308, a second film side 310 (Fig. 8), and perforations 326, 328, 330, 332, 334, 336 (Fig. 9) using a laser, The remaining insulating film 304 may be etched using an etchant containing, for example, ammonium ethoxide, potassium hydroxide or other suitable material to obtain a more elaborate thin film probe 302. In the embodiment, the thin film probe can be manufactured by using a semiconductor packaging process, and the package manufacturer does not need an additional design. Therefore, the thin film probe is low in manufacturing cost and simple in method, and is very suitable for mass production.

FIG. 10 is a cross-sectional view of a probe card 448 having a probe structure 438 for use in an electrical tester in accordance with an embodiment. The probe structure 438 serves as a probe core. The guide 450 having the array of perforations of the first conductive end 416 of the corresponding conductive strip 406 is utilized, so that during the test, the first conductive end 416 can pass through the perforation of the guide 450 to fix and control The position of the first conductive tip 416 is made such that it can be aligned with the device under test to form a good electrical contact and an accurate test result is obtained.

Referring to FIG. 10, the probe structure 438 can also be used in conjunction with the space transformer 452, wherein a wire (not shown) in the space transformer 452 is in electrical contact with the second conductive end 418 of the conductive strip 406 to correspond. The board 454 expands the spacing of contact points such as pads or bumps and conforms to the design of the contact points of the board 454. In some embodiments, for example, the probe structure 438 having the conductive strips 406 fanned in the X direction can be used with a spatial transducer 452 that is fanned in the Y direction (not shown). The position of the components of the probe card 448 can be secured by fasteners 456, 458, such as screws.

As shown in FIG. 10, an external signal processor (not shown) can maintain signal coupling relationship with the conductive strips 406 of the probe structure 438 through the circuit board 454 and the space converter 452, and the device to be tested, such as a semiconductor integrated circuit chip. Conduct an electrical test.

As shown in Fig. 10, the general space converter 452 uses a hard material such as a ceramic material or boiler soil (BT) as a substrate having internal wires therein. The inner lead exposed on the substrate is provided with a connection pad for making electrical contact with the conductive strip 406 of the probe structure 438 and the circuit board 454. The space converter 452 is limited by process factors. For example, the ceramic material as the substrate is formed by a sintering technique, and the internal perforation or the pitch of the wires cannot be made smaller than 50 μm. Therefore, in the embodiment, it is necessary to use the flexible material together. The probe structure 438 is fabricated as a probe head for the purpose of testing the device to be tested with a contact point spacing of less than 50 μm. It should be understood that the probe structure 438 in the embodiment is not limited to being a probe core, which can also function as a space transformer.

Referring to FIG. 11, a cross-sectional view of a probe card 560 having a probe structure 538 for use in an electrical tester in accordance with an embodiment is shown. The elastic film 562 has a circuit design such as a wire or a contact bump. During the test, the platen 564 pushes the elastic film 562 toward the contact probe structure 538, whereby the circuit board 554 coupled to an external signal (not shown) and the conductive strip of the probe structure 538 can be utilized by the elastic film 562. 516 has an electrically coupled relationship that allows the conductive strip 516 to be electrically tested by a component to be tested (not shown), such as a semiconductor integrated circuit wafer. In some embodiments, a space transformer (not shown) may also be disposed on the probe structure 538, and during testing, the platen 564 pushes the elastic film 562 toward the contact space transducer, thereby utilizing the elastic film 562. The circuit board 554 is electrically coupled to the probe structure 538. The position of the components of the probe card 560 can be secured by fasteners 556, 558, such as screws.

12 to 17 illustrate a manufacturing process of a semiconductor structure according to an embodiment, wherein an electrical tester can be used to electrically test a semiconductor structure to obtain electrical parameters of the semiconductor structure, such as resistance, inductance, and capacitance. Value and so on.

Referring to Figure 12, perforations 668 are defined in substrate 666, such as a crucible substrate. An insulating layer 670 is formed on the sidewalls of the vias 668. The perforations 668 are filled with a conductive layer 672. The insulating layer 670 may include epoxy, benzocyclobutene (BCB), polyimide (PI), or other suitable materials. Conductive layer 672 can comprise a metal such as nickel, gold, copper, tungsten, titanium, palladium or alloys thereof.

Referring to FIG. 13, a conductive redistribution layer 674 is formed on the conductive layer 672, and a bump 676 is formed on the conductive redistribution layer 674. Conductive redistribution layer 674 can be formed in the dielectric layer 678 and electrically connected to the bump 676 to the conductive layer 672. In an embodiment, the structure shown in FIG. 13 can be electrically tested, such as an open test, using probe cards 448, 560 as shown in FIG. 10 or FIG.

Referring to FIG. 14, the structure shown in FIG. 13 is attached to the carrier 680.

Referring to Figure 15, the substrate 666 is thinned until the conductive layer 672 in the via 668 is exposed.

Referring to FIG. 16, a conductive redistribution layer 682 is formed on the conductive layer 672, and a bump 684 is formed on the conductive redistribution layer 682. A conductive redistribution layer 682 can be formed in the dielectric layer 686 and electrically connected to the bumps 684 to the conductive layer 672. Referring to FIG. 17, a film frame 688 is attached to the bump 684 and electrically connected to the bump 684. In some embodiments, the semiconductor structure shown in FIG. 17 acts as a carrier and electrical testing such as a short test can be performed at this step. Thereafter, other devices to be tested, such as a semiconductor integrated circuit chip (not shown), may be attached to the film holder as shown in FIG. 17, carried by the carrier and electrically connected to the semiconductor integrated circuit chip, and may be utilized, for example. The probe cards 448, 560 shown in Fig. 10 or Fig. 11 were electrically tested. The embodiment is not limited to electrical testing of the semiconductor integrated circuit using the carrier as shown in FIG. 17, but other suitable carriers may be used according to actual needs.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

102, 202, 302‧‧‧film probe

104, 204, 304‧‧‧ insulating film

106, 206, 306, 406‧‧‧ Conductive strips

108, 308‧‧‧ first film side

110, 310‧‧‧ second film side

112, 212‧‧‧ first film surface

114, 214‧‧‧ second film surface

116, 216, 316, 416, 516‧‧‧ first conductive end

118, 218, 318, 418‧‧‧ second conductive end

120‧‧‧Electrical bumps

122‧‧‧ lower surface

124‧‧‧ upper surface

126, 128, 130, 132, 134, 136, 226, 228, 230, 232, 234, 236, 326, 328, 330, 332, 334, 336, 668‧ ‧ piercing

238, 438, 538‧‧ ‧ probe structure

240‧‧‧ Positioning parts

342‧‧‧Insulation layer

344‧‧‧Support substrate

346‧‧‧ Conductive layer

448, 560‧ ‧ probe card

450‧‧‧ Guide

452‧‧‧ Space Converter

454, 554‧‧‧ circuit board

456, 458, 556, 558‧‧‧ fixing parts

562‧‧‧elastic film

564‧‧‧ pressure plate

666‧‧‧Substrate

670‧‧‧Insulation

672‧‧‧ Conductive layer

674, 682‧‧‧ Conductive redistribution

676, 684‧‧ ‧ bumps

678, 686‧‧‧ dielectric layer

680‧‧‧ Carrier Board

688‧‧‧ film holder

D1, D2, D3‧‧‧ spacing

T1, T2‧‧‧ thickness

W1, W2‧‧‧ width

1 is a top view of a film probe according to an embodiment.

FIG. 2 is a schematic perspective view of a probe structure according to an embodiment.

3 is a cross-sectional view of a probe structure in accordance with an embodiment.

Figure 4 illustrates a conductive strip of a probe structure in accordance with an embodiment.

5 to 9 illustrate a method of fabricating a thin film probe according to an embodiment.

Figure 10 is a cross-sectional view of a probe card in accordance with an embodiment.

Figure 11 is a cross-sectional view of a probe card in accordance with an embodiment.

12 through 17 illustrate a fabrication process of a semiconductor structure in accordance with an embodiment.

102‧‧‧Film probe

104‧‧‧Insulation film

106‧‧‧ Conductive strip

108‧‧‧First film side

110‧‧‧Second film side

112‧‧‧First film surface

114‧‧‧Second film surface

116‧‧‧First conductive end

118‧‧‧Second conductive end

120‧‧‧Electrical bumps

122‧‧‧ lower surface

124‧‧‧ upper surface

126, 128, 130, 132, 134, 136‧ ‧ piercing

D1, D2‧‧‧ spacing

W1, W2‧‧‧ width

Claims (10)

A probe structure comprising a film probe, the film probe comprising: an insulating film having a first film surface and a second film surface, and having a first film side and a first film a second film side, the insulating film is made of a flexible material; and a plurality of conductive strips are disposed on the first film surface of the insulating film, the conductive strips each having a first conductive end and a second conductive end, the first conductive end extends beyond the first film side of the insulating film, and the conductive strips separated from each other are fan-shaped, such that the first conductive ends of the conductive strips The spacing is less than the spacing of the second conductive ends. The probe structure of claim 1, wherein each of the second conductive ends of the conductive strips has conductive bumps and is located on a side of the second film of the insulating film. The probe structure of claim 1, comprising a plurality of the film probes disposed one on another, wherein the first film surface of one of the film probes faces the The film probe is the other of the second film surface. The probe structure of claim 3, further comprising a plurality of positioning members, configured to pass through a plurality of perforations defined by the insulating films of the film probes to position the films in an overlapping configuration Probe. The probe structure of claim 1, wherein the first conductive ends of the conductive strips have a pitch of between 20 μm and 50 μm. Such as the probe structure described in claim 1 of the patent scope, wherein the probe The needle structure is used as a space transformer or probe head for an electrical tester. A method for manufacturing a thin film probe includes: forming a conductive layer on an insulating material layer; patterning the conductive layer to form a plurality of conductive strips, each of the conductive strips having a first conductive end and a first The conductive strips are separated from each other by a fan shape, such that the spacing of the first conductive ends of the conductive strips is smaller than the spacing of the second conductive ends; and removing a portion of the insulating material layer An insulating film is formed, the insulating film has a first film side and a second film side, and each of the first conductive ends of the conductive strips extends beyond the first film side of the insulating film . The method of manufacturing a thin film probe according to claim 7, wherein in the step of removing a portion of the insulating material layer to form the insulating film, the insulating film defines a plurality of perforations. The method for manufacturing a thin film probe according to claim 7, wherein the method of removing a portion of the insulating material layer comprises a laser method, wherein the insulating film defines the perforated laser power system to be larger than the cut The laser power of the side of the first film of the insulating film. The method of manufacturing a thin film probe according to claim 7, wherein the insulating material layer is composed of a flexible material, and the method of manufacturing the thin film probe further comprises forming the conductive layer on the insulating material layer. Prior to the layer, the insulating material layer is disposed on a support substrate composed of a hard material.