CN101726641B - Manufacturing method of conductive elastomer - Google Patents

Abstract

The present invention is a method for manufacturing a conductive elastomer, wherein a first metal sacrificial layer is coated on a substrate having a plurality of grooves, a first photoresist layer is formed thereon, a plurality of first openings are opened on the first photoresist layer so that they correspond to the grooves respectively, a gel containing conductive particles is then filled into the first openings, and the gel is solidified to form a plurality of first elastic columns. Then, the above steps are repeated to form a second metal sacrificial layer, a second photoresist layer, a plurality of second openings, and a plurality of second elastic columns are formed to correspond to the top of the first elastic columns. Finally, the second photoresist layer, the second metal sacrificial layer, the first metal sacrificial layer, and the substrate are removed, and only the first photoresist layer and the plurality of first elastic columns and second elastic columns dispersed therein are left, which are stacked one on top of the other.

Description

Manufacturing method of conductive elastomer

technical field

The invention relates to a method for manufacturing a conductive elastic body, in particular to a method for manufacturing a conductive elastic body by using a micro-electromechanical technology.

Background technique

In the chip packaging and testing process, in order to save test time and cost, it is often necessary to test multiple devices under test (DUT) at one time, especially for ball grid array (BGA) and other array solder ball tests. . The means adopted by the known technology all use the design method of the probe (Pogo pin) to cooperate with the test socket (Socket) to achieve the purpose of testing. However, as technology continues to evolve and the pitch of package solder balls (Pitch) becomes smaller and smaller, the known testing methods are subject to many limitations in design and assembly, and cannot meet the existing requirements.

Therefore, a conductive elastomer has been developed to replace the conventional method of matching the probe with the test socket. Its working principle is to use a conductive elastomer as a conductive interconnect (Interposer) or connector (Connector), and it can be used in the case of small pitches, especially for asymmetrical solder ball arrangements.

In addition, compared with general traditional probes, conductive elastomers are very suitable for high-frequency testing due to their short path, low inductance, low impedance and long life. However, the conductive elastomers currently tested are very expensive and the manufacturing process is quite complicated. Therefore, due to cost considerations, many test factories do not actually introduce a large number of conductive elastomers into the test production line, but only conduct tests on a small number of specific products.

It can be seen that how to develop a low-cost, high-efficiency, simple process, and a manufacturing method that can mass-produce conductive elastomers is an urgent need in the industry.

Contents of the invention

The purpose of the present invention is to provide a method for manufacturing a conductive elastomer to meet the needs of modern industries.

To achieve the above object, the method for manufacturing the conductive elastomer provided by the present invention includes the following steps: (A) providing a substrate, and a plurality of grooves are provided on the upper surface of the substrate. (B) Coating a first metal sacrificial layer on the upper surface of the substrate and in the plurality of grooves. (C) forming a first photoresist layer on the upper surface of the first metal sacrificial layer. Next, (D) removing the first photoresist layer to form a plurality of first openings, wherein the plurality of first openings respectively correspond to the plurality of grooves of the substrate. (E) and filling the gel containing conductive particles into the plurality of first openings, and then curing to form a plurality of first elastic columns.

Then, (F) coating a second metal sacrificial layer on the upper surface of the first photoresist layer and on the plurality of first elastic columns. (G) Forming a second photoresist layer on the upper surface of the second metal sacrificial layer. (H) Removing the second photoresist layer to form a plurality of second openings, wherein the plurality of second openings respectively correspond to the plurality of first elastic pillars.

Next, (I) filling the gel containing conductive particles into the plurality of second openings, and curing to form a plurality of second elastic columns. (J) removing the second photoresist layer and the second sacrificial metal layer, and removing the first sacrificial metal layer and the substrate. Accordingly, the manufacturing method of the conductive elastomer of the present invention can greatly reduce the manufacturing cost, simultaneously enable mass production, simplify the overall manufacturing procedure and the requirements for process equipment, and make it easier to flexibly adjust process variables according to different needs.

Wherein, step (E) of the present invention can scrape the gel doped with metal conductive particles into a plurality of first openings, and step (I) can scrape the gel doped with metal conductive particles into a plurality of second openings Inside, this is the so-called gel technology. In addition, the method of coating the first metal sacrificial layer in step (B) of the present invention and the method of coating the second metal sacrificial layer in step (F) can be at least one of the following: vacuum sputtering, electroplating, chemical deposition, electroless Electroplating, or other equivalent processes or techniques can be applied in the present invention. In addition, the method for forming the first photoresist layer in step (C) and the second photoresist layer in step (G) of the present invention may be at least one of the following: printing, roller coating, spray coating, curtain coating coating, spin coating, or other equivalent process or technique.

Furthermore, the method of forming a plurality of first openings in step (D) and forming a plurality of second openings in step (H) of the present invention can use exposure and development methods, or other methods that can define the size of the openings and remove the photoresist of the openings. Equivalent processes are available. Also, the plurality of first elastic pillars in step (E) of the present invention and the plurality of second elastic pillars in step (I) doped with metal particle material can be at least one of the following: gold, copper, nickel, aluminum, Silver, or other conductive particles are acceptable.

Preferably, the material used in the first metal sacrificial layer in step (B) of the present invention and the second metal sacrificial layer in step (F) can be at least one of the following: copper, nickel, chromium, titanium, or Other equivalent metal material. In addition, the plurality of first elastic columns in step (E) of the present invention, and the plurality of second elastic columns in step (I) can be cylinders, rectangular columns, even trapezoidal or tapered columns, or other geometric polygonal columns. . Accordingly, the thickness of the first photoresist layer in step (C) of the present invention can be 150 to 200 microns (μm), and the thickness of the first metal sacrificial layer in step (B) can be 0.2 to 0.5 microns (μm) ).

Description of drawings

1A to 1J are schematic cross-sectional views of a conductive elastomer according to a preferred embodiment of the present invention.

FIG. 2 is a schematic perspective view of a conductive elastomer according to a preferred embodiment of the present invention.

FIG. 3 is a schematic diagram of a preferred embodiment of the present invention mass-produced on the same substrate.

Explanation of main component symbols in the drawings

1 Substrate 11 Upper surface 12 Groove

2 first metal sacrificial layer 21 upper surface 3 first photoresist layer

31 first opening 32 first elastic column 33 upper surface

4 second metal sacrificial layer 41 upper surface 5 second photoresist layer

51 The second opening 52 The second elastic column 6 Conductive elastomer

Detailed ways

Please refer to FIG. 1A to FIG. 1J , which are schematic cross-sectional views of a preferred embodiment of a method for manufacturing a conductive elastomer of the present invention. However, the present invention uses micro-electro-mechanical technology to manufacture conductive elastomers with low cost and high efficiency. However, the present invention is not limited to the micro-electro-mechanical process, and the present invention can also be realized by using a semiconductor process or other equivalent processes. The following will describe the micro-electro-mechanical process as a preferred embodiment.

Please refer to FIG. 1A and FIG. 3 at the same time. Firstly, a substrate 1 is provided, and a plurality of grooves 12 are pre-set on the upper surface 11 of the substrate 1 . The plurality of grooves 12 can be pre-machined by a CNC machine tool. In addition, the substrate 1 can be reused to achieve the purpose of reducing costs. As shown in FIG. 3 again, FIG. 3 is a schematic diagram of a preferred embodiment of the present invention mass-produced on the same substrate. As shown in the figure, this embodiment uses micro-electro-mechanical technology, which can achieve an array-type processing method, which means that several or even dozens of conductive elastic materials can be processed at the same time on the same substrate according to the size of the elastomer design and the size of the substrate. body, the cost can be reduced by mass production.

As shown in FIG. 1B , a first sacrificial metal layer 2 is coated on the upper surface 11 of the substrate 1 and inside the plurality of grooves 12 . In this embodiment, vacuum sputtering is used for coating, but of course, vapor deposition, electroplating, chemical deposition, and electroless plating can also be used. The first metal sacrificial layer 2 coated in this embodiment is made of nickel, of course, it can also be chromium, copper, titanium, or other metal materials, and its thickness is 0.2 to 0.5 microns (μm).

As shown in FIG. 1C , a first photoresist layer 3 is formed on the upper surface 21 of the first metal sacrificial layer 2 . The method of its formation is spin coating (Spin coating), of course, printing (Printing), roller coating (Roller coating), spray coating (Spray coating), curtain coating (Curtain coating), etc. Way. The thickness of the first photoresist layer 3 is 150 to 200 micrometers (μm) in this embodiment, of course, it can be changed according to the different requirements of the actual thickness of the conductive elastomer. However, the first photoresist layer 3 of this embodiment uses photoresist materials with elastic properties, and the commonly used models are as follows AZ-4620, JSR-120N, JSR-151N, S1813, and SU8.

As shown in FIG. 1D , the first photoresist layer 3 is then removed by exposure and development to form a plurality of first openings 31 , wherein the plurality of first openings 31 respectively correspond to the plurality of grooves 12 of the substrate 1 . In this embodiment, the advantage of using photoresist coating method and exposure method by lithography technology is that it is easy to control the thickness of the elastic body, especially in accordance with the design of the photomask, and any shape of the elastic body structure can be easily manufactured, such as a cylinder , rectangular columns, or other geometric polygonal columns. Even shapes with different thicknesses up and down can be controlled by adjusting the depths of the plurality of grooves 12 on the substrate 1 and the thickness of the first photoresist layer 3 . In addition, the different characteristics of photoresist and the exposure and development technology of the exposure machine can be used to manufacture cylinders with different cross-sectional areas at the upper and lower ends, such as cone-shaped or trapezoidal structures, to meet special requirements for testing.

As shown in FIG. 1E , the gel containing conductive particles is filled into the plurality of first openings 31 and cured to form a plurality of first elastic pillars 32 . This embodiment adopts the gel technology (Sol-Gel Process), that is, the gel doped with metal particles is scraped in and filled into the plurality of first openings 31, and is cured to form a plurality of first elastic pillars 32. . However, the gel used in this example is a thermosetting polymer material, so it has elasticity and can work normally in a high temperature environment.

According to this, the most commonly used thermosetting gel in the industry is based on silicone rubber, and different modifiers are added to achieve different effects due to different property requirements. For example, ethylene-propylene-diene rubber (EPDM ), acrylate rubber (ACM), fluororubber (FKM), polyurethane rubber (PU), or diene rubber, etc. And the material of its doped metal particle is gold, certainly also can be nickel, aluminium, silver, copper or other metal particles with conductive property, also can mix the particle of different materials simultaneously, make the first elastic column 32 have better Properties such as conductivity or elasticity are presented.

As shown in FIG. 1F , a second metal sacrificial layer 4 is then coated on the upper surface 33 of the first photoresist layer 3 and the plurality of first elastic pillars 32 . The second sacrificial metal layer 4 is the same as that of the first sacrificial metal layer 2 described above. In this embodiment, vacuum sputtering is used, and evaporation, electroplating, chemical deposition, and electroless plating can also be used. The material is also nickel, but of course it can also be chrome, copper, titanium, or other metal materials.

As shown in FIG. 1G , a second photoresist layer 5 is formed on the upper surface 41 of the second metal sacrificial layer 4 . Here, the second photoresist layer 5 is the same as the first photoresist layer 3 , and its formation method is the same as spin coating, of course, printing, roller coating, spray coating, curtain coating and other methods can also be used.

As shown in FIG. 1H, the second photoresist layer 5 is then removed by exposing and developing to form a plurality of second openings 51, and the plurality of second openings 51 correspond to the plurality of first elastic pillars 32 and A plurality of grooves 12 on the substrate 1 .

As shown in FIG. 1I , the gel containing conductive particles is also filled into the plurality of second openings 51 and cured to form a plurality of second elastic pillars 52 . Its second elastic column 52 also adopts the gel technology (Sol-Gel Process), that is, the gel doped with metal particles is scraped in and filled into the plurality of second openings 51, and is cured to form a plurality of second openings 51. Elastic column 52. The material of the metal particles is gold, which can also be nickel, aluminum, silver, copper or other conductive metal particles, and particles of different materials can also be mixed in at the same time.

Please refer to FIG. 1J and FIG. 2 at the same time. Finally, the second photoresist layer 5 and the second sacrificial metal layer 4 are removed, and the first sacrificial metal layer 2 and the substrate 1 are removed. That is to say, the first photoresist layer 3 and the plurality of first elastic columns 32 are lifted off from the first metal sacrificial layer 2 (Strip or Lift off). Therefore, the final product conductive elastomer 6 is shown in Figure 1J and Figure 2, which includes the main elastic body that provides elastic support, that is, the first photoresist layer 3 left on purpose, a plurality of first elastic columns 32, a plurality of first Two elastic pillars 52 and the second sacrificial metal layer 4 between the first elastic pillar 32 and the second elastic pillar 52 .

The above-mentioned embodiments are only examples for convenience of description, and the scope of rights claimed by the present invention should be based on the scope of claims in the application, rather than limited to the above-mentioned embodiments.

Claims (17)

1. manufacture method of conducting elastic body may further comprise the steps:

(A) provide a substrate, the upper surface of this substrate is provided with plurality of grooves;

(B) coating one first sacrificial metal layer on the upper surface of this substrate, and this plurality of grooves in;

(C) form one first photoresist layer on the upper surface of this first sacrificial metal layer;

(D) remove this first photoresist layer to form a plurality of first openings, these a plurality of first openings correspond respectively to this plurality of grooves of this substrate;

(E) insert contain conducting particles gel in these a plurality of first openings, and solidify to form a plurality of first elasticity posts;

(F) coating one second sacrificial metal layer on the upper surface of this first photoresist layer, and these a plurality of first elasticity posts on;

(G) form one second photoresist layer on the upper surface of this second sacrificial metal layer;

(H) remove this second photoresist layer to form a plurality of second openings, these a plurality of second openings correspond respectively to this a plurality of first elasticity posts;

(I) insert contain conducting particles gel in these a plurality of second openings, and solidify to form a plurality of second elasticity posts; And

(J) remove this second photoresist layer, and this second sacrificial metal layer, and remove this first sacrificial metal layer and this substrate.

2. manufacture method of conducting elastic body as claimed in claim 1, wherein, this step (E) is that the gel that is doped with conductive metal particles is scraped in these a plurality of first openings, and solidify to form this a plurality of first elasticity posts after drying.

3. manufacture method of conducting elastic body as claimed in claim 1, wherein, this step (I) is that the gel that is doped with conductive metal particles is scraped in these a plurality of second openings, and solidify to form this a plurality of second elasticity posts after drying.

4. manufacture method of conducting elastic body as claimed in claim 1, wherein, the method for this first sacrificial metal layer of coating is selected from a kind of in vacuum splashing and plating, plating, chemogenic deposit and the electroless plating in this step (B).

5. manufacture method of conducting elastic body as claimed in claim 1, wherein, the method for this second sacrificial metal layer of coating is selected from a kind of in vacuum splashing and plating, plating, chemogenic deposit and the electroless plating in this step (F).

6. manufacture method of conducting elastic body as claimed in claim 1, wherein, the method that forms this first photoresist layer in this step (C) is selected from printing, roller coating, spray coating, curtain type is coated with and rotary coating in a kind of.

7. manufacture method of conducting elastic body as claimed in claim 1, wherein, the method that forms this second photoresist layer in this step (G) is selected from printing, roller coating, spray coating, curtain type is coated with and rotary coating in a kind of.

8. manufacture method of conducting elastic body as claimed in claim 1, wherein, the method that forms these a plurality of first openings in this step (D) is to utilize the exposure imaging mode.

9. manufacture method of conducting elastic body as claimed in claim 1, wherein, the method that forms these a plurality of second openings in this step (H) is to utilize the exposure imaging mode.

10. manufacture method of conducting elastic body as claimed in claim 1, wherein, the material of this plural conductive particle is that to be selected from the group that is made up of gold, copper, nickel, aluminium and silver wherein a kind of in this step (E).

11. manufacture method of conducting elastic body as claimed in claim 1, wherein, the material of this plural conductive particle is that to be selected from the group that is made up of gold, copper, nickel, aluminium and silver wherein a kind of in this step (I).

12. manufacture method of conducting elastic body as claimed in claim 1, wherein, the material that this first sacrificial metal layer is used in this step (B) be selected from by copper, nickel, chromium, and the group that forms of titanium wherein a kind of.

13. manufacture method of conducting elastic body as claimed in claim 1, wherein, the material that this second sacrificial metal layer is used in this step (F) be selected from by copper, nickel, chromium, and the group that forms of titanium wherein a kind of.

14. manufacture method of conducting elastic body as claimed in claim 1, wherein, these a plurality of first elasticity posts are right cylinder in this step (E).

15. manufacture method of conducting elastic body as claimed in claim 1, wherein, these a plurality of second elasticity posts are right cylinder in this step (I).

16. manufacture method of conducting elastic body as claimed in claim 1, wherein, the thickness of this first photoresist layer is 150 to 200 microns in this step (C).

17. manufacture method of conducting elastic body as claimed in claim 1, wherein, the thickness of this first sacrificial metal layer is 0.2 to 0.5 micron in this step (B).

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