TW201306403A - Connector and fabrication method thereof - Google Patents

Abstract

The present invention provides a connector including a substrate, at least a conductive via disposed inside the substrate, a pad disposed on one surface of the substrate and electrically connecting with the conductive via, a resilient flange disposed on the pad, and an anisotropic conductive adhesive interposed between the pad and the resilient flange to electrically connect the pad with the resilient flange.

Description

Connector structure and manufacturing method thereof

The present invention relates to a connector structure, and more particularly to a connector structure using an anisotropic conductive paste and a method of fabricating the same.

As the signal input/output count (I/O pin count) and density of integrated circuit chips continue to increase, the process of connecting the chip modules to the printed circuit board becomes extremely challenging. In the past, as shown in Fig. 1, the packaged wafer module 1 is usually soldered directly to the printed circuit board 3. However, if the soldered wafer module 1 is to be replaced in the future, the entire circuit board must be returned to the supplier. In order to remove, replace, and then link, resulting in increased costs.

In order to avoid the above problems, the industry has developed a technique for placing an interposer between the packaged wafer module and the printed circuit board. As shown in FIG. 2, a connector 50 is provided. The connector 50 can be interposed between a carrier (not shown) and a printed circuit board (not shown). The connector 50 includes a substrate 12. A plurality of elastic contacts 20 are disposed on one side of the substrate 12, and the elastic contacts 20 are electrically connected to the plated through holes 11 in the substrate 12 through the conductive layer 16 on the surface of the elastic contacts 20. The elastic contact member 20 and the substrate 12 are separately fabricated, and the elastic contact member 20 is pressed against the adhesive layer 15 on the substrate 12, for example, a low-flow prepreg.

However, the above prior art still has drawbacks that require further improvement and improvement. Since the technique of fabricating the connector 50 in a circuit board manner in the past utilizes the adhesive layer 15 to first fix a copper foil (the plurality of elastic contact members 20 on the copper foil) on the substrate 12, and then use electroless plating to make a bottom, followed by Electroplating of copper, nickel, gold, etc. is used as electrical conduction and surface treatment, so that the process is cumbersome and costly, and the electrical connection between the elastic contact 20 and the plated through hole 11 in the substrate 12 is only By the conductive layer 16, it is easy to be damaged and affect the electrical transmission quality.

Accordingly, it is a primary object of the present invention to provide an improved connector structure and method of making the same that addresses the deficiencies and shortcomings of the prior art described above.

In order to achieve the above object, according to a preferred embodiment of the present invention, a connector structure includes a substrate; at least one conductive hole is disposed in the substrate; and a pad is disposed on a surface of the substrate and electrically A conductive hole is connected; an elastic contact member is disposed on the pad; and an anisotropic conductive adhesive is disposed between the pad and the elastic contact member for electrically connecting the pad and the elastic contact member.

According to another preferred embodiment of the present invention, a method of fabricating a connector includes providing a substrate having at least one conductive via; forming a pad on a surface of the substrate; and pressing on the surface of the substrate An anisotropic conductive adhesive and at least one elastic contact member electrically connect the elastic contact member to the pad via the anisotropic conductive adhesive.

The above described objects, features and advantages of the present invention will become more apparent from the description of the appended claims. However, the following preferred embodiments and drawings are for illustrative purposes only and are not intended to limit the invention.

3 to 9 are schematic views showing a method of manufacturing a connector according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the substrate 100. The substrate 100 may be a multilayer wiring board or a single layer wiring board. As shown in FIG. 3, the substrate 100 is a two-layer circuit board comprising a core layer 120 and having a conductive layer (not shown), such as a copper foil, on the surface 101 of the substrate 120. Next, a plurality of conductive holes are formed in the substrate 120, and the conductive holes may be plated through holes or conductive blind holes. According to a preferred embodiment of the present invention, the conductive vias are formed by the via holes 110 and are formed by drilling and plating processes, wherein the plated vias 110 can penetrate both sides of the substrate 120. Next, an etching process is performed on the conductive layer to form a layout line. The etching process described above also forms a plurality of pads 140 on the surface 101 of the substrate 120, and the pads 140 are electrically connected to the plated through holes 110. It should be noted that the pad 140 is electrically connected to the pad 142 of the lower surface 102 through the conductive layer 130 on the sidewall of the plated through hole 110. Moreover, in accordance with an embodiment of the present invention, the plurality of pads 140 are arranged in an array.

4 to 5 are schematic views showing a method of fabricating a copper foil according to an embodiment of the present invention. As shown in FIG. 4, a copper foil 200 is provided which may comprise beryllium copper alloy or other copper-containing composite metal. It is known that beryllium copper alloy has a high stress strength and an elastic modulus, so that it is less likely to cause plastic deformation during the process of the reverse forming. Then, nickel is selectively plated on at least one side 200a of the copper foil 200, and then a selective gold plating process is performed, and the non-gold-plated surface area can be covered by a photoresist (not shown) and plated on the gold-plated surface area. A layer of metal gold 210. It is known that in addition to strengthening the adhesion between the metal gold 210 and the copper foil 200, the nickel can also increase the elastic modulus of the copper foil 200 to enhance the elastic restoring force of the subsequent elastic contact 201 during use. The metal gold 210 system prevents oxidation of the gold-plated surface area or reacts with the external environment. Thereafter, a process such as etching, molding, or the like is used to form the elastic contact member 201 arranged in an array as shown in FIG. The resilient contact 201 is a metal flange. The resilient contact 201 includes a base 230, an intermediate extension 240 having a curvature, and a contact end 250. The contact tip 250 includes nickel, metal gold 210, or a combination of the two.

Next, reference is made to Figs. 6 and 7. 6 is a schematic view showing the structure of the connector in which the copper foil 200 in FIG. 5 is simultaneously pressed with an anisotropic conductive paste 150 and the substrate 100, and a circuit manufacturing process is performed, and FIG. 7 is a connector of FIG. A perspective view of the structure. As shown in FIG. 6, the copper foil 200 is simultaneously pressed together with an anisotropic conductive paste 150 and the substrate 100, and then a circuit manufacturing process is performed to etch a portion of the copper foil 200 of the inelastic contact 201 to form a copper foil 200. Connector 500. Since the anisotropic conductive adhesive 150 has been stamped to form the through hole 150a corresponding to the plated through hole 110 before pressing, according to the embodiment of the present invention, the pressed anisotropic conductive adhesive 150 can cover the pad 140. However, the plated through holes 110 are not covered or plugged. It should be noted that the composition of the anisotropic conductive adhesive 150 includes conductive particles and a polymer material, which has the characteristics of unidirectional conduction in addition to bonding and fixing the copper foil 200 to the substrate 100. In the present embodiment, the anisotropic conductive paste 150 has conductivity only in the vertical direction Z of the surface 101 of the vertical substrate 100, and depending on the need for conductivity, it is possible to select different conductive particle sizes and material anisotropy. Conductive adhesive 150. As shown in FIG. 7 , the elastic contact 201 directly contacts the anisotropic conductive adhesive 150 only through the base 230 , and the elastic contact 201 can be electrically connected to the pad 140 via the anisotropic conductive adhesive 150 . Since the step of plating nickel or gold 210 on the contact tip 250 is completed before the elastic contact 201 is pressed, the procedure is more simplified. In a subsequent process, the connector 500 can be utilized to enable the packaged wafer module to be electrically coupled to the internal circuitry of the printed circuit board through the resilient contact 201.

Fig. 8 is a partially enlarged schematic view showing the structure of the connector at the dotted circle in Fig. 6. As shown in FIG. 8, the anisotropic conductive paste 150 is disposed between the pad 140 and the base 230 of the elastic contact 201. When the elastic contact member 201 is subjected to a pressure perpendicular to the vertical direction Z of the surface 101, a force is also generated in the vertical direction Z of the anisotropic conductive paste 150, thereby shortening the upper surface 153 of the anisotropic conductive paste 150. The distance from the lower surface 155 increases the conductivity of the anisotropic conductive paste 150 in the vertical direction Z (the conduction position and direction are as indicated by the double arrow 152). It should be noted that in this embodiment, since the plane XY is not subjected to an external force, the anisotropic conductive paste 150 has no conductivity on the plane XY, that is, the anisotropic conductive paste 150 is only The vertical direction Z is electrically conductive and is electrically insulating on the plane XY. In addition, it is worth noting that since the elastic contact 201 is electrically connected to the pad 140 only through the anisotropic conductive adhesive 150, the sidewall 151 of the anisotropic conductive adhesive 150 does not need to be formed by electroplating or electroless plating. Conductive layer.

FIG. 9 is a cross-sectional view showing a connector placed between a carrier of a wafer module and a printed circuit board according to an embodiment of the invention. As shown in FIG. 9, the connector 500 is interposed between the chip package 400 and the printed circuit board 600, wherein the position of the pad 410 corresponds to the contact end 250, and the position of the solder ball 160 corresponds to the printed circuit. The pads 610 of the board 600. The chip package 400 can be electrically connected to the printed circuit board 600 through the connector 500.

Figure 10 is a schematic view showing the structure of a connector according to another preferred embodiment of the present invention. The only difference between the 10th and the 6th is that the conductive holes in the substrate 720 are conductive blind holes 710, and the material thereof comprises a low-resistance metal or alloy such as copper or aluminum, and the conductive blind holes 710 can penetrate the substrate 720. Both sides of the two sides are connected to the pads 140 and 142, respectively. Similarly, as shown in FIG. 6, the elastic contact 201 of FIG. 10 is also a metal cantilever arm. The elastic contact 201 includes a base 230, an intermediate extension 240 having a curvature, and a contact end 250. The contact tip 250 includes nickel, metal gold 210, or a combination of the two. Similarly, the anisotropic conductive adhesive 150 is present between the elastic contact 201 and the substrate 720. The anisotropic conductive adhesive 150 has a unidirectional conductivity in addition to the elastic contact 201 and the substrate 720. characteristic. In the present embodiment, the anisotropic conductive paste 150 has conductivity only in the vertical direction Z. Therefore, the base portion 230 of the elastic contact member 201 is electrically connected to the pad 140 only via the anisotropic conductive paste 150.

In summary, the present invention provides a connector 500 structure having an anisotropic conductive adhesive 150 disposed on the substrate 120, 720, such that the elastic contact member 201 and the pad 140 are passed through the anisotropic conductive adhesive 150. Electrical connection. By the fact that the anisotropic conductive paste 150 has a conductivity characteristic only in the vertical direction Z, the process of electrically connecting the elastic contact 201 and the pad 140 by electroplating or electroless plating can be omitted. In addition, since the contact tip 250 is plated with nickel, metal gold 210 or a combination of the two before the elastic contact 201 is pressed on the anisotropic conductive paste 150, the metal plating process after the pressing process can be omitted. The complexity of the process is reduced and the cost is reduced, and the disadvantage that the conductive layer of the electrical connection elastic contact piece and the plated through hole is easily damaged is also improved.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

1. . . Chip module

3. . . A printed circuit board

11. . . Plating through hole

12. . . Substrate

15. . . Low flow prepreg

16. . . Conductive layer

20. . . Elastic contact

50. . . Connector

100. . . Substrate

101. . . surface

102. . . lower surface

110. . . Plating through hole

120. . . Substrate

130. . . Conductive layer

140. . . Pad

142. . . Pad

150. . . Anisotropic conductive adhesive

150a. . . perforation

151. . . Side wall

152. . . Two-way arrow

153. . . Upper surface

155. . . lower surface

200. . . Copper foil

200a. . . side

201. . . Elastic contact

210. . . Metal gold

230. . . Base

240. . . Intermediate extension

250. . . Contact end

400. . . Chip package

410. . . Pad

420. . . Wafer

500. . . Connector

600. . . A printed circuit board

610. . . Pad

710. . . Conductive blind hole

720. . . Substrate

Z. . . Vertical direction

XY. . . flat

The following drawings are intended to provide a more complete understanding of the invention, and are described in detail herein. The specific embodiments of the present invention are described in detail by reference to the specific embodiments herein,

FIG. 1 is a schematic view showing a conventional packaged wafer module soldered to a printed circuit board.

Figure 2 shows the structure of a conventional connector.

3 to 9 are schematic views showing a method of manufacturing a connector according to an embodiment of the present invention, wherein:

Figure 3 is a schematic cross-sectional view of the substrate;

4 to 5 are schematic views showing a method of fabricating a copper foil according to an embodiment of the invention;

Figure 6 is a schematic view showing the structure of the connector in which the copper foil in Fig. 5 is simultaneously pressed with an anisotropic conductive paste and a substrate, and a circuit manufacturing process is performed;

Figure 7 is a perspective view of the connector structure of Figure 6;

Fig. 8 is a partially enlarged schematic view showing the structure of the connector at the dotted circle in Fig. 6.

FIG. 9 is a cross-sectional view showing a connector placed between a carrier of a wafer module and a printed circuit board according to an embodiment of the invention.

FIG. 10 is a schematic structural view of a connector according to another preferred embodiment of the present invention.

It is worth noting that all drawings are for illustrative purposes only. For the purpose of explanation, the size and proportion of the components drawn in the drawings may be enlarged or reduced. In the different embodiments, the same element symbols will be used to represent corresponding or similar features.

101. . . surface

120. . . Substrate

130. . . Conductive layer

140. . . Pad

150. . . Anisotropic conductive adhesive

151. . . Side wall

152. . . Two-way arrow

153. . . Upper surface

155. . . lower surface

230. . . Base

Z. . . Vertical direction

XY. . . flat

Claims (10)

A connector structure includes: a substrate; at least one conductive hole disposed in the substrate; a pad disposed on a surface of the substrate and electrically connecting the conductive hole; an elastic contact member disposed on the And an anisotropic conductive adhesive disposed between the pad and the elastic contact for electrically connecting the pad and the elastic contact. The connector structure of claim 1, wherein the elastic contact member is a metal cantilever arm. The connector structure of claim 1, wherein the anisotropic conductive paste has electrical conductivity only in a direction perpendicular to the surface of the substrate. The connector structure of claim 1, wherein the pad and the elastic contact are electrically connected only through the anisotropic conductive adhesive. The connector structure of claim 1, wherein the anisotropic conductive paste does not cover the conductive hole. A method of manufacturing a connector, comprising: providing a substrate having at least one conductive hole; forming a pad on a surface of the substrate, electrically connecting the conductive hole; and pressing a surface on the surface of the substrate The anisotropic conductive adhesive and the at least one elastic contact member electrically connect the elastic contact member to the pad via the anisotropic conductive adhesive. The method of fabricating the connector of claim 6, wherein the anisotropic conductive paste has electrical conductivity only in a direction perpendicular to the surface of the substrate. The method of manufacturing the connector of claim 6, wherein the anisotropic conductive adhesive does not cover the conductive hole. The method of manufacturing the connector of claim 6, wherein the resilient contact member comprises a base portion, an intermediate extension portion having a curvature, and a contact end. The method of manufacturing the connector of claim 9, wherein the contact tip is plated with nickel, gold or a combination of the two before the elastic contact is pressed onto the anisotropic conductive paste.