KR100312872B1 - Spring contact elements - Google Patents

Abstract

Spring contact elements are fabricated by depositing at least one layer of metallic material into an opening defined in a mask layer deposited on a surface of a substrate, which may be an electronic component such as an active semiconductor device. Each spring contact element has a base end, a contact end and a central body portion. The contact end is offset in the base end in the z-axis (with different heights) in at least one x and y direction. In this way, a plurality of spring contact elements are fabricated in the spatial relationship described with each other on the substrate. The spring contact elements form a temporary (ie pressurized) or permanent (eg, soldered or brazed or bonded with conductive adhesive) connection with the terminal of another electronic component. In exemplary applications, spring contact elements are deposited on a semiconductor embedded on a semiconductor wafer such that temporary connections can be made into the semiconductor device to burn in and / or test the semiconductor device.

Description

Spring Contact Element {SPRING CONTACT ELEMENTS}

Co-owned US patent application Ser. No. 08 / 152,812 filed November 16, 1993 by KHANDROS (US Pat. No. 4,576,211, issued December 19, 1995), and correspondingly in 1995 Co-owned pending US patent application No. 08 / 457,479 filed Jan. 1 (state: pending) and 08 / 570,230 filed December 11, 1995 (state: pending) Mounting an end of a flexible long core element (eg, a wire “stem” or a “skeleton”) to a terminal on the component, and the adjacent spring of the flexible core element and the terminal to a final spring Elastic interconnect suitable for microelectronic applications comprising coating with a "shell" made of one or more materials having a predetermined combination of thickness, yield strength and modulus of elasticity to ensure the predetermined force-bending properties of the contact For manufacturing urea It discloses a method. Exemplary materials for the core element include gold. Typical coating materials include nickel and alloys thereof. The final spring contact element is suitably used to effectively represent a pressurizable or dismountable connection between two or more electronic components including semiconductor devices.

Co-owned pending US patent application Ser. No. 08 / 340,144, filed Nov. 15, 1994 by Candid and MATHIEU, and PCT Patent Application No. PCT /, filed November 16, 1994, corresponding thereto. US94 / 1337 (International Publication No. WO95 / 14314, filed May 26, 1995) discloses a number of applications suitable for the spring contact elements described above, as well as techniques for manufacturing contact pads at the ends of the spring contact elements. . For example, in its FIG. 14, a number of depressions or holes (which may be in the form of inverted pyramid ends at vertices) are formed on the surface of a sacrificial layer (substrate). These holes are then filled with contact structures consisting of layers of material such as gold or rhodium and nickel. The long flexible element can be mounted to the final contact structure and overcoated in the manner described above. In the last step, the sacrificial layer is removed. The final spring contact has a contact pad with a controlled shape (eg a sharp point) at its free end.

Co-owned pending US patent application Ser. No. 08 / 452,255, filed May 26, 1995 by ELDRIDGE, GRUBE, Candros and Matthew, and correspondingly November 13, 1995. PCT Patent Application No. PCT / US95 / 14909 (June 6, 1996, WO96 / 17278) filed with, discloses a number of additional techniques and metallurgical techniques for manufacturing contact tip structures on a sacrificial substrate, as well as a number of Techniques for moving spring contact elements collectively to terminals of an electronic component are disclosed (see, for example, FIGS. 11A-11F and 12A-12C).

PCT Patent Application No. 60 / 005,189, co-owned, filed May 17, 1996 by Eldridge, Candros and Matthew, and PCT Patent Application No. 24, 1996, corresponding thereto. / US96 / 08107 (International Publication No. WO96 / 37332, filed Nov. 28, 1996) includes a number of contact tip structures (see, for example, # 620 in FIG. 6B) that are already mounted to electronic component # 630. Techniques are disclosed for bonding to a number of long contact elements (see, for example, # 632 in FIG. 6D). This patent application also discloses a technique for manufacturing a “long” contact tip structure, for example in the form of a cantilever in FIGS. 7A-7E. The cantilever tip structure can be tapered between one end and the opposite end thereof. The cantilevered tip structure of this patent application is an already existing (i.e., first manufactured) raised mutually extending (e.g., free standing) extending from the corresponding terminal (e.g., # 734 in Figure 7F) of the electronic component. Suitable for mounting on connecting elements (eg # 730 in 7F).

In co-owned pending US Provisional Patent Application No. 60 / 024,555, filed Aug. 26, 1996 by Eldridge, Kandros and Matthew, a number of long tip structures having different lengths have their inner ends at their inner ends. Techniques that can be arranged to be disposed at a pitch greater than the ends are disclosed, for example, in FIGS. 2A-2C. Their inner “contacting” ends may be collinear with each other to effectively represent a connection to electronic components having terminals disposed along a line, such as the center line of the component.

The present invention solves and is particularly suitable for forming interconnections in modern microelectronic devices with their terminals (bond pads) arranged at fine pitch. As used herein, the term “fine pitch” refers to a microelectronic device having their terminals disposed at intervals less than 5 mils, such as 2.5 mils or 65 μm. As is evident from the description below, this is preferably achieved by utilizing the advantages of dense tolerances that can be easily implemented by using photolithography rather than mechanical techniques to produce contact elements.

FIELD OF THE INVENTION The present invention relates to elastic (spring) contact (interconnect) elements (structures) suitable for making pressurized and / or flexible connections between electronic components, and more particularly to microminiature spring contact elements.

<Cross Reference to Related Application>

This patent application is a partial continuing application of co-owned and pending US Patent Application No. 60 / 030,697, filed November 13, 1996, which is incorporated herein by reference.

This patent application is issued under co-owned US Patent Application No. 08 / 452,255, filed May 26, 1995 (hereinafter referred to as “parent application”) and PCT, filed November 13, 1995, corresponding thereto. Part of the continuing application of patent application PCT / US95 / 14909, both of which are co-owned pending US patent application Ser. No. 08 / 340,144, filed November 15, 1994, and corresponding thereto, November 1994. Part of the continuing application of PCT Patent Application No. PCT / US94 / 13373, filed on December 16, both of which are incorporated in pending US patent application Ser. No. 08 / 152,812, filed on November 16, 1993 (1995). US Patent No. 5,476,211, issued Dec. 19, 2008, which is incorporated herein by reference in its entirety.

Furthermore, this patent application is part of a series of co-owned pending US patent applications;

08 / 554,902, filed November 9, 1995 (PCT / US95 / 14844, November 13, 1995);

08 / 558,332, filed November 15, 1995 (PCT / US95 / 14885, November 13, 1995);

60 / 012,027, filed February 15, 1996 (PCT / US96 / 08117, 1996.5.24);

60 / 005,189, filed May 17, 1996 (PCT / US96 / 08107, 1996.5.24);

60 / 024,555, filed August 26, 1996;

08 / 784,862, filed January 15, 1997;

08 / 802,054, filed February 18, 1997; And

08 / 819,464, filed May 17, 1997;

All patent applications are still part of the above-described parent application, and are incorporated herein by reference.

Preferred embodiments of the invention are described in detail, examples of which are illustrated in the accompanying drawings. The drawings are intended to be illustrative, and not limiting. Although the invention will be described in the context of these preferred embodiments, it should be understood that this is not intended to limit the spirit and scope of the invention to these specific embodiments. Certain elements in selected ones of the figures are illustrated for clarity but not inclusive. Often, like elements are referred to by like reference numerals throughout the drawings. For example, element 199 is similar in all respects to element 299 in other figures. Also, like elements are often referred to by like reference numerals in a single figure. For example, multiple elements 199 may be referred to as 199a, 199b, 199c, and the like.

1A is a side cross-sectional view of a technique for making a spring contact element in accordance with the present invention.

1B is a side cross-sectional view of the spring contact element of FIG. 1A, in accordance with the present invention.

1C is a perspective view of the spring contact element of FIG. 1B, in accordance with the present invention.

2A illustrates a system application for a spring contact element on a semiconductor device, in accordance with the present invention.

2B is a plan view of a portion of FIG. 2A.

3A is a side cross-sectional view of another embodiment of a spring contact element, in accordance with the present invention.

3B is a top view of the spring contact element of FIG. 3A, in accordance with the present invention.

3C is a side cross-sectional view of another embodiment of a spring contact element, in accordance with the present invention.

4A and 4B are side cross-sectional views illustrating techniques applicable to equalizing an efficient length of multiple spring contact elements, in accordance with the present invention.

5 is a perspective view of another embodiment of a spring contact element, in accordance with the present invention.

6A is a side cross-sectional view of a first stage in a technique for achieving controlled impedance within a spring contact element, in accordance with the present invention.

6B is a side cross-sectional view of the next step in the technique for achieving controlled impedance within a spring contact element, in accordance with the present invention.

6C is an end cross-sectional view of the controlled impedance spring contact element of FIG. 6B, in accordance with the present invention.

It is an object of the present invention to provide an improved technique for manufacturing spring contact elements.

It is another object of the present invention to provide a technique for fabricating a spring contact element using a process that is inherently suitable for the field of tight tolerances of fine pitch of microelectronics.

It is a further object of the present invention to provide a technique for manufacturing a micro spring contact element without damaging the semiconductor device on an active electronic device such as a semiconductor device. This involves fabricating a micro spring contact element on a semiconductor device inherent on the semiconductor wafer before the semiconductor devices are singulated from the semiconductor wafer.

It is yet another object of the present invention to produce a spring contact element suitable for socketing (releasably connecting) an electronic component, such as a semiconductor device, to perform burn-in on the device. It is to provide a technique for doing this.

According to the present invention, a spring contact element is formed by photolithographically forming one or more openings corresponding to one or more mask layers, depositing a conductive metal material in the three-dimensional opening, and subsequently removing the mask layer. Manufactured on the same electronic component and having a base (base) end adjacent to the surface of the part and a contact (end) end (also referred to as a "tip end" or "free end") spaced apart from each other horizontally and vertically from the base end. Generate one spring contact element. Multiple spring contact elements can be produced in this way on parts up to (extremely fine) tolerance by photolithography.

The spring contact elements of the present invention are suitable for making temporary or permanent electrical connections to terminals of other electronic components such as printed circuit boards (PCBs).

In order to make a temporary connection, the part from which the spring contact elements are manufactured is conveyed together with the other electronic parts such that the tip ends of the spring contact elements are in pressure contact with the terminals of the other electronic part. The spring contact elements act resiliently to maintain contact pressure and electrical connection between the two parts.

In order to make a permanent connection, the part from which the spring contact elements are made is joined to the tip ends of the spring contact elements by soldering or brazing to the terminals of the other electronic component or with a conductive adhesive. The spring contact elements are compliant and accommodate different thermal expansion between the two electronic components.

The spring contact element is at least one layer of metal material selected for its ability to cause the final contact structure to normally act as a spring (ie, exhibit an elastic deformation) when an external force is applied to its contact (free) end. As appropriately formed.

The spring contact elements of the present invention can be manufactured directly on the surface of a semiconductor device or on the surface of many semiconductor devices inherent on a semiconductor wafer. In this manner, a number of semiconductor devices inherent on a semiconductor wafer can be prepared for burn-in and / or testing before being unified from the semiconductor wafer.

Other objects, features and advantages of the invention will be apparent in light of the following description.

Co-owned pending US Provisional Patent Application No. 60 / 030,697, filed November 13, 1996, discloses a technique for manufacturing a free upright elastic (spring) contact element of Electronic Components, for example, FIGS. 4A-FIG. In 4C, it is disclosed. In general, a plurality of insulating layers having openings formed therein are aligned and "seed" with a layer of conductive material. The material of the conductive material may be formed (or deposited) in the seeded opening by electroplating (or CVD, sputtering, electroless plating, etc.). After the insulating layers are removed, the materials will act as free upright elastic contact structures that are not only perpendicular to the surface of the part but also extend laterally from where they are mounted. In this way, the contact structures are easily designed to be flexible not only in the z axis but also in the x-y plane (parallel to the surface of the part). This is described in detail below with reference to FIGS. 1A-1C.

1A is an example for fabricating one of a number of free upright elastic (spring) contact elements on a substrate 102, which may be an active electronic component including a semiconductor device inherent on a semiconductor wafer (not shown). The technique 100 is shown.

Substrate 102 has multiple (one shown) regions 112 on its surface from which spring contact elements are fabricated. In the case of a substrate 102 that is an electronic component (such as a semiconductor device), these regions 112 will be terminals (such as bond pads) of the electronic component.

In general, the technique 100 includes applying a plurality of (three shown) pattern mask layers 104, 106, 108 with openings on the surface of the substrate. The layers are patterned to align the openings (as shown) with the area 112, and the openings are defined for a layer (eg, 108) with an opening in one layer (eg, 108 or 106) underlying it. For 106 and 106, the size and shape extends further from area 112 than the opening in 104. In other words, the first layer 104 has an opening just above the region 112. A portion of the opening in the second layer 106 is aligned over at least a portion of the opening in the first layer 104, and conversely, a portion of the first layer 104 is below a portion of the opening in the second layer 106. Extend. Similarly, a portion of the opening in the third layer 108 is aligned over at least a portion of the opening in the second layer 106, and conversely, a portion of the second layer 106 is formed of the opening in the third layer 108. Some extend down. The bottom of a given total opening is directly above the selected area 112, the top of which is raised from its bottom and offset laterally. As will be described in detail below, the conductive metal material is deposited into the opening and the mask layers are removed to extend both over the surface of the substrate and the base end secured to the substrate 102 in the region 112 and the region 112. To create a free standing contact structure displaced laterally.

If desired, as in the case of electroplating, a very thin (eg 450 nm) “seed” layer of conductive material 114 such as titanium / tungsten (TiW) may be deposited into the opening. Subsequently, a material of conductive metal material (eg, nickel) 120 may be deposited into the opening by electroplating.

1B and 1C show the proximal end 122 adjacent the region 112 and the z-axis above the surface of the substrate 102 as well as lateral to the x- and y-axes from the proximal end 122. Shows a final spring contact element 120 with a free end (tip) 124 offset to.

As best shown in Fig. 1C, the contact element 120 is indicated by an arrow 124, as a result of forming a temporary pressurized electrical connection with a terminal (not shown) of another electronic component (not shown). As applied to the z-axis at its tip end 124. Flexibility in the z-axis ensures that the contact force (pressure) is maintained and also accommodates nonplanarity (if any) between terminals (not shown) on other electronic components (not shown). This temporary electrical connection is useful for making a temporary connection to the electrical component 102, such as to perform burn-in and / or testing of the component 102.

Tip end 124 is also free to flexibly move in the x- and y- directions, as indicated by arrows 136 and 134, respectively. This joins the tip end 124 (by soldering or brazing or with a conductive adhesive) to a terminal (not shown) of another electronic component (not shown) that has a different coefficient of thermal expansion than the substrate [component 102]. This is important in the category. This permanent electrical connection is intended for the assembly of electronic components, such as a number of memory chips (represented by substrate 102, respectively) to other electronic components, such as interconnection substrates such as printed circuit boards (“PCBs”; Is suitable as.

By appropriate choice of materials and shapes, the materials 120 thus produced can function as free standing elastic contact structures fabricated from each other at very precise dimensions and at very precise intervals. For example, these tens of thousands of spring contact elements 120 are easily and accurately fabricated on the corresponding many terminals on a semiconductor device inherent on a semiconductor wafer (not shown).

In this manner, at least one layer 104, 106, 108 of mask material is applied on the surface of the substrate 102 and spaced apart from the region 112 on the substrate over the surface of the substrate and laterally from the region 112. And / or patterning the mask layer to have openings extending to a position that is offset across, selectively applying seeding 114 to the openings, and opening at least one layer of conductive metal material And removing the mask material such that the remaining conductive metal material forms a free upright contact element extending from the surface of the substrate, such that the spring contact elements 120 are formed on the semiconductor wafer, such as an electronic component. A method of manufacturing directly on a substrate, such as an inherent semiconductor device, is shown, with each contact element being a base adhered to one region of the substrate. And a tip end for forming an electrical connection to the end and the terminal of the electronic component.

<Material>

The structure (spring contact element) 120 is basically, preferably entirely, metal and may be formed (manufactured) as a multilayer structure. Suitable materials for one or more layers of the contact structure include, but are not limited to, nickel and its alloys, and copper, cobalt, iron, and alloys thereof, and gold (especially hard, exhibiting excellent current carrying capability and good contact resistance properties). Hard gold and silver, elements of the platinum group, noble metals, semi-noble metals and their alloys, especially elements of the palladium group, and Alloys thereof and tungsten, molybdenum, other refractory metals and alloys thereof.

If a solder-like finish is desired, tin, lead, bismuth, indium and alloys thereof may also be used.

<Application (use) example for spring contact element>

As mentioned above, the spring contact element 120 of the present invention is useful for making a temporary electrical connection to the part 102 from which the spring contact elements are made, such as for burn-in and / or testing of the parts. Co-owned pending US patent application Ser. No. 08 / 784,862, filed Jan. 15, 1997, discloses a system for performing wafer level burn-in and testing in its FIG. 1A (rewritten here as FIG. 2A). It became.

2A shows an exemplary system 200 for performing wafer level burn-in and testing of multiple semiconductor devices 200 (200a, 200b, 200c, 200d) inherent on a semiconductor wafer. Spring contact elements 210 (compare 120) are fabricated on each semiconductor device and are shown very schematically. Each device is shown with four of many spring contact elements protruding (approximately) from the surface. The entire semiconductor wafer is suitably mounted on a heat controlled platen 204 platen.

The test substrate includes an interconnect substrate 208 having a plurality of active electronic devices 206 (206a, 206b, 206c, 206d) mounted on its front surface. These devices are suitably application-specific integrated circuits (ASICs). Thermally controlled platen 204a may be mounted to the backside of interconnect substrate 208. The ASICs 206 are connected to the interconnect substrate 208 in a suitable manner such as by bond wires (not shown). The host computer 216 and power supply 218 are connected to the ASIC via the interconnect substrate 208. Suitable securing means 212, 214 may allow the wafer 202 to interconnect the interconnect substrate 208 until the spring contact element 210 is in pressure contact with a terminal on the front side (bottom side as observed) of the ASIC 206. And can be aligned and moved thereafter, after which the semiconductor device 202 can be powered, burned, and tested, including simultaneously actuating all of the devices 202 on the wafer.

2B, corresponding to FIG. 1B of co-owned pending US patent application Ser. No. 08 / 784,862, is a schematic diagram illustrating contact of one of the semiconductor devices 202a with a corresponding single circuit of the ASIC 206a, and a spring contact element. 210 can be fabricated such that one of them 210a, 210b is relatively long and the other of them 210c, 210d is relatively short, and the tip end (shown in a circle) of the spring contact element is their base. Some of these 210a, 210c extend in one direction from the center row of bond pads 207 (shown as rectangles) and others of them 210b, 210d so as to be at a pitch greater than the ends (distance between the two). The silver may be manufactured to extend in the opposite direction from the center row of the bond pads 207.

<Size and Shape of Spring Contact Element>

Since the spring contact elements of the present invention are suitably formed using micromachining techniques such as photolithography and plating, the shape and size of the spring contact elements are easily controlled to the correct dimensions.

3A-3C are schematic views of spring contact elements 300, 350 (compared to 120) fabricated in accordance with the techniques of the present invention.

The spring contact element 300 of Figures 3A and 3B has a base end 302, a contact (tip) end 304, a main body portion 306 therebetween, an overall length ("L"), Have an overall height ("H"). As shown, the main body portion 306 is offset from the base end 302 by a distance "d2" in one direction and offset from the contact end 304 by a distance "d1" in another direction. For example, the distance "d2" will be determined by the thickness of the first mask layer (compare 104), and the distance "d1" is determined by the thickness of the final mask layer (compare 108). Will be decided. As shown in the plan view of FIG. 3B, the contact element 300 has its base end 302; A widthwise taper "α" may be provided and tapered to be narrower (width "w1") at its contact end 302 than width "w2"].

3C has a base end 352 (compare 302), a contact (tip) end 354 (compare 304), and a main body portion 356 (compare 306) between them. Is a schematic view of a similar spring contact element 350 with respect to the contact element 300. In this example, the contact element 350 has its base end 302; A thickness taper ("β") may be provided to be thicker (thickness "t2") at its contact end 304 than thickness "t1"].

<Example dimensions>

The spring contact elements of the present invention are particularly suitable for forming interconnections between microelectronic components. Dimensions appropriate for the spring contact element use the parameters described below (in mil, unless otherwise specified).

size range Desirable range

L 10-1000 60-100

H 4-40 5-12

d1 3-15 7 ± 1

d2 0-15 7 ± 1

w1 3-20 8-12

w2 1-10 2-8

t1 1-10 2-5

t2 1-10 1-5

α 0-30 ° 2-6 °

β 0-30 ° 0-6 °

<Adjust the behavior of the spring contact element>

The possibility of having spring contact elements of different lengths from each other has been described above (see, eg, FIG. 2B). Multiple spring contact elements of different lengths inherent on a single electronic component all exhibit the same spring coefficient k and, although not preferred, provide suitable taper angles for each contact element in the manner discussed with respect to FIGS. 3B and 3C. It is possible to "main culture". Another more convenient way of equalizing the spring coefficients of spring contact elements of different lengths is described with reference to FIGS. 4A and 4B.

In either case, i.e., whether the base end 302 is wider than the tip end 304 (FIG. 3B), or if the base end 352 is thicker than the tip end 354, the base ends 302, 352 are the tip ends. It has a larger cross section than 304 and 354.

4A shows a spring contact element 400 fabricated on an electronic component 410. The spring contact element 400 has a base end 402 (compare 302), a contact end 404 (compare 304), a main body portion 406 (compare 306), between the base end and the contact end. Has a full length (L). The spring contact element 400 is characterized by a base end 402 and a main body portion (eg, to exhibit "behavior" as if it were shorter (e.g., to exhibit similar behavior to shorter spring contact elements on the same part). The continuation of 406 is a point located at a distance "L1" along the body portion 406 from the contact end 404 with a suitable encapsulant (eg, epoxy) that "cures" the spring contact element. Up to ("P").

4B shows another technique for tailoring the mechanical performance of a spring contact element 450 (compared to 400) fabricated on an electronic component 460 (compared to 410). The spring contact element 450 has a base end 452 (compare 402), a contact end 454 (compare 404), a main body 456 (compare 406), between the base end and the contact end. Has a full length (L). The spring contact element 450 is a main body contiguous with the base end 452 to exhibit "behavior" as if it is shorter (e.g., to exhibit similar behavior to shorter spring contact elements on the same part). A portion of the portion 406 continues up to the point P, which "steps" to rise above the surface of the part. As in the example 400 above, the point P is located at a distance L1 along the body portion 456 from the contact end 454.

The portion of the spring contact element 450 that "follows" along the surface of the component 460 is the "tail" end of the spring contact element 450. Except using this technique to equalize the spring coefficient (FIG. 4B), the surface of the component 460 such that the tail end of the spring contact element fabricated in accordance with the present invention executes "path formation" from a given terminal on the component. It is within the gist of the present invention to extend along any direction along. In this way, for example, the peripheral arrangement of the component terminals can be changed to an area array of tips 454, and vice versa. It is also within the spirit of the present invention that the “tails” 462 of two or more spring contact elements 450 may intersect each other to facilitate a more complex path forming design. See also FIG. 3D of PCT / US95 / 14885, discussed above, in which the form of path formation incorporating a spring contact element is discussed.

<Other Example>

Clearly, a high degree of control can affect the size, shape and orientation of the spring contact elements made in accordance with the present invention.

5 shows a spring contact element (compare 120) with a base end 502, a contact end 504, and a body portion 506 therebetween. In this example, the body portion is "jog" in the x, y plane (parallel to the surface of the part when fabricated) such that the contact end 504 is at a different x, y, z coordinate than the base end 502. do. In other words, when the body portion 506 crosses the y axis, it displaces (jogs) in the x axis.

<Controlled impedance>

It is advantageous for the spring contact element to have a controlled impedance for use in probes of semiconductor devices, in particular for conducting speed tests.

6A-6C illustrate a technique 600 for achieving controlled impedance at a spring contact element in accordance with the present invention.

In a first step, which is shown well in FIG. 6A, the spring contact element 600 (compare 400) is connected to the terminal 612 of the electronic component 610 (compare 410) by its base end 602. Is mounted. The contact tip end 604 (compare 404) is raised above the surface of the component 610. The spring contact structure has a central body portion 606 (compare 406) between the base and tip ends.

In the next step, which is shown well in FIG. 6B, the tip end 604 of the spring contact element is masked (not shown) and a suitably thin (eg 1-10 μm) insulating layer such as parylene 620 is deposited over the entirety of the tip end 604 of the spring contact element and the adjacent surface of the electronic component by vapor deposition.

In the next step well shown in Figure 6B, while the tip end 604 of the spring contact element is still masked (not shown), a moderately thin (e.g., 0.25) of conductive material, such as the conductive metal material described herein, layer 622 is deposited over the tip end 604 of the spring contact element and all but the adjacent surface of the electronic component by sputtering. Finally, tip end 604 is masked off. This generates the central body portion 606 of the spring contact element surrounded by the conductive layer 622 with the insulating layer 620 therebetween.

The conductive layer 622 is suitably connected to ground to act as a ground plane and to control the impedance of the final spring contact element. For example, as best shown in Figure 6B, component 610 is provided with a second terminal 614, which is an electrical ground. This terminal 614 is suitably masked with the tip end 604 of the spring contact element before applying the insulating layer 620 so that a subsequent conductive layer 622 is also deposited thereon and connected thereto.

Ultimately, the thicknesses of the layers 620 and 622 need to be sufficient to provide a continuous and in demand controlled impedance, and should not be such that they interfere with the mechanical operation of the spring contact element. 6B and 6C are not drawn to scale.

Although the invention has been shown and described in detail in the drawings and above description, it should be considered as illustrative and not restrictive-only preferred embodiments are to be understood as being shown and described, and all modifications encountered within the spirit of the invention and It is understood that modifications must be required to be protected. Undoubtedly, many other "modifications" in the "topic" disclosed above will occur to those skilled in the art to which the invention pertains, and such modifications are intended to be within the spirit of the invention as described herein.

For example, the final spring contact elements can be heat treated to improve their mechanical properties. In addition, the heat injected to permanently connect (eg, by brazing) the spring contact element to the part can advantageously be used to “heat treat” the material of the spring contact element.

Claims (23)

A method of making a spring contact element on a substrate, Applying at least one layer of mask material onto the surface of the substrate and patterning the mask layer to have openings extending from a region on the substrate to a position on the surface of the substrate and laterally and / or laterally offset from the region; , Depositing at least one layer of conductive metal material into the opening; Removing the mask material such that the remaining conductive metal material forms a free upright contact element each having a base end secured to one of the regions of the substrate and a free upright end for forming an electrical connection and extending from the surface of the substrate. Method consisting of. The method of claim 1, further comprising seeding the opening in at least one layer of mask material prior to depositing at least one layer of conductive metal material. The method of claim 1 wherein the substrate is an electrical component. The method of claim 1 wherein the substrate is a semiconductor device. The method of claim 1 wherein the substrate is a semiconductor wafer. The method of claim 1, further comprising forming an opening in the at least one mask layer such that the base ends of the final spring contact elements have a larger cross section than the tip ends of the final spring contact elements. A method of forming an electrical connection between at least one first electronic component and a second electronic component, the method comprising: Manufacturing by a method according to claim 1 a spring contact element each having a tip end spaced on a surface of the at least one first electronic component directly on at least one first electronic component; And bringing said at least one first electronic component together with the second electronic component such that the tip end of the spring contact element is in electrical contact with the corresponding terminals on the second electronic component. 8. The method of claim 7, further comprising maintaining pressure between the at least one electronic component and the second electronic component. 8. The method of claim 7, wherein the at least one first electronic component is at least one active semiconductor device, and the second electronic component is a test substrate, Powering said active semiconductor element while maintaining tip ends of spring contacts in electrical contact with a terminal of said second electronic component. 10. The method of claim 9, wherein the at least one active semiconductor device is embedded on a semiconductor wafer. 8. The method of claim 7, wherein the at least one first electronic component is at least one memory chip. 8. The method of claim 7, wherein the tip end of the spring contact element is joined to a corresponding terminal of the second electronic component. In a spring contact element made according to the method of claim 1, Consisting of an elongated member of length ("L") having a base end, a contact end opposite the base end, a central body portion continuous with each of the base and contact ends, The contact end is offset at a distance “d1” from the center in a first direction, The base end is offset from the central portion by a distance “d2” in a second direction opposite the first direction, And the base end is secured to the region of the first electronic component and the tip end is adapted in use for pressurized connection with the second electronic component. 14. A spring contact element as claimed in claim 13 wherein the spring contact element is thicker at the base end than at the contact end. 14. The spring contact element of claim 13 wherein the spring contact element is wider at the base end than at the contact end. 14. The spring contact element of claim 13 wherein said length ("L") is in the range of 10 to 1000 mils. 17. The spring contact element of claim 16 wherein the length "L" is in the range of 60 to 100 mils. 14. The elongated member according to claim 13, wherein the elongate member has an overall height "H" which is the sum of "d1" and "d2" and a thickness at the central body of the member, And said overall height ("H") is in the range of 4 to 40 mils. 19. The spring contact element of claim 18 wherein the overall height " H " is in the range of 5 to 12 mils. The method of claim 13, wherein the spring contact element comprises nickel and its alloys, copper, cobalt, iron, and alloys thereof, gold (particularly hard gold) and silver, elements of the platinum group, precious metals, and Precious metals and their alloys, in particular the elements of the palladium group and their alloys, and tungsten, molybdenum, other refractory metals and their alloys, and materials consisting of tin, lead, bismuth, indium and their alloys Spring contact element, characterized in that it has at least one layer selected. In a semiconductor device having a plurality of terminals (bond pads) on the surface, Further comprising a plurality of spring contact elements fabricated directly on the surface of the semiconductor device, Each spring contact element has a base end at the corresponding one of the bond pads and a tip end disposed over the / surface of the substrate and laterally and / or laterally offset from the base end, The spring contact element applies at least one layer of mask material on the surface of the semiconductor device and extends from the bond pad on the semiconductor device to a position on the surface of the semiconductor device and laterally and / or laterally offset from the bond pad. Patterning the mask layer to have openings, depositing at least one layer of conductive metal material into the opening, and removing the mask material such that the remaining conductive metal material forms a free standing spring contact element. A semiconductor device. The device of claim 21, wherein each spring contact element has a tail continuous with the base end, And the tail portion of the spring contact element performs path formation. In a semiconductor wafer, A plurality of semiconductor devices inherent thereon, A plurality of spring contact elements fabricated directly on the semiconductor device inherent on the semiconductor wafer, The semiconductor device inherent on the semiconductor wafer is prepared for burn-in and testing before being unified from the semiconductor wafer, The spring contact elements apply at least one layer of mask material on the surface of the semiconductor wafer, and are laterally from the bond pad and on the surface of the semiconductor wafer from bond pads on the semiconductor device inherent on the semiconductor wafer; Pattern the mask layer to have openings extending to a laterally offset position, depositing at least one layer of conductive metal material into the opening, and allowing the remaining conductive metal material to form a free standing spring contact element. A semiconductor wafer produced by removing the mask material.