TWI473181B - Package substrate with electrical connection structure and preparation method thereof - Google Patents

Description

Package substrate with electrical connection structure and preparation method thereof

The present invention relates to a package substrate and a method for fabricating the same, and more particularly to a package substrate having an electrical connection structure and a method of fabricating the same.

At present, the electrical connection between the semiconductor chip and the package substrate includes two technologies: wire bonding and Flip Chip, wherein the wire-bonding package electrically connects the semiconductor chip to the package substrate by wire bonding. The flip-chip package structure is disposed on the package substrate with the active surface facing down, and is soldered and electrically connected to the package substrate by a plurality of bumps. The crystalline package structure does not require the use of a space-consuming bonding wire, and the telecommunications transmission distance is short to electrically connect the semiconductor wafer to the package substrate, thereby making the overall package structure lighter, thinner and shorter. In the current packaging technology, when a packaged circuit is mounted on a package substrate on which a semiconductor wafer is mounted, a plurality of ball grid arrays (BGAs) must be implanted on the bottom surface of the package substrate. The solder ball is electrically connected to the external electronic device (such as a printed circuit board).

At present, a method for fabricating a solder material on an electrical connection pad (including a wafer connection region and a ball placement region) of a package substrate is a stencil printing technique. The invention mainly comprises forming an insulating protective layer with an insulating protective layer opening on a package substrate on which the circuit wiring is completed, and exposing a plurality of electrical connecting pads, so that a template having a plurality of die holes is placed on the insulating protection of the package substrate On the layer, through the die holes, a solder stack is formed on the electrical connection pads. A scraper or spray can be used to deposit the solder in the die hole, and after the template is removed, a solder bump is formed. The reflow process is repeated to cure the solder bump on the electrical connection pad to form a solder structure.

Please refer to FIGS. 1A and 1B for a partial schematic view showing the formation of a solder material on an electrical connection pad of a package substrate, and an insulating protection layer 11 is formed on a package substrate 10 having an electrical connection pad 12. And the insulating protective layer 11 has an opening 11a, and the electrical connecting pad 12 forms a corner C of nearly 90 degrees with the opening 11a, so that when the solder material is formed in the opening 11a, the corner C The line is at an angle of about 90 degrees, so that the solder material is not easily deposited in the corner C. In addition, when the soldering material is subjected to the reflow process, since the solder material is not solidified, the liquid metal cohesive force and the surface tension are not completely filled in the corner C of the 90 degree, so that the reflow process is performed. A gap S is formed between the formed solder structure 15 and the insulating protective layer 11 (as shown in FIG. 1B), and bubbles are formed therein, so that a problem of poor reliability such as peeling of the solder structure 15 occurs in a subsequent process. .

In addition, since the solder material is not completely filled in the corner between the electrical connection pad and the opening of the insulating protective layer, the contact area between the solder material and the electrical connection pad is reduced, which makes the solder material of the subsequent solder structure difficult to be formed. Adhered to the electrical connection pad, thereby affecting the quality of the solder ball and the electrical connection performance of the package substrate.

Moreover, the solder structure 15 prevents the solder structure 15 from overflowing only by the solder resisting property of the insulating protective layer 11 in the reflow process, but the solder structure 15 is in a liquid state during reflow, as applied to fine pitch electric When the package substrate of the connection pad is connected, the two adjacent solder structures 15 are easily short-circuited due to overflow bridging; therefore, the spacing between the solder structures 15 must be increased, so that the use of the fine pitch package substrate cannot be provided. demand.

Therefore, in view of the above problems, how to avoid the formation of solder materials in the prior art is difficult, a gap is formed between the formed solder structure and the insulating protective layer, the electrical connection quality of the solder structure and the package substrate cannot be improved, and the solder structure is returned. Problems such as overflow in the welding process have become a problem that is currently being solved.

In view of the above-mentioned deficiencies of the prior art, it is an object of the present invention to provide a package substrate having an electrical connection structure and a method of manufacturing the same, which prevents the solder material from overflowing in the reflow process and causing a short circuit.

Another object of the present invention is to provide a package substrate having an electrical connection structure and a method of fabricating the same, which provides a fine pitch electrical connection structure.

A further object of the present invention is to provide a package substrate having an electrical connection structure and a method of manufacturing the same, which improves the bonding between the solder material formed on the metal layer and the electrical connection pads to prevent detachment.

To achieve the above and other objects, the present invention discloses a package substrate having an electrical connection structure, comprising: a package substrate body having a plurality of electrical connection pads on at least one surface thereof, and having a surface on the surface and the electrical connection pads An insulating protective layer having an opening corresponding to each of the electrical connection pads, exposing a portion of the surface of the electrical connection pad; a plating adhesion layer disposed on an exposed surface of the electrical connection pad; and a metal The layer is located on the plating adhesion layer, the sidewall of the insulating protective layer and the insulating protective layer on the surface outside the opening.

According to the above structure, the sidewall of the insulating plating layer and the insulating protective layer on the surface of the opening of the opening and the conductive layer are provided on the lower surface of the metal layer.

Further, according to the above structure, the surface of the metal layer has a solder material; or the surface of the metal layer has a surface treatment layer, and the surface treatment layer has a solder material; or the upper surface and the side surface of the metal layer It has a surface treatment layer and has a solder material on the outer surface of the surface treatment layer.

The plating adhesion layer is nickel/gold (Ni/Au, which is formed by nickel first, then gold is formed), nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), and nickel-palladium immersion gold (Electroless Nickel/Electroless) Palladium/Immersion Gold, ENEPIG), Immersion Tin, and Direct Immersion Gold (DIG); the solder material is tin-lead (Sn/Pb), tin-silver (Sn/) One of Ag), tin-silver-copper (Sn/Ag/Cu), tin-copper (Sn/Cu), tin (Sn), and low-melting solder of lead-free solder; the metal layer is copper (Cu), gold (Au ), one of silver (Ag) and high lead (high lead) high melting point metals.

The invention provides a method for manufacturing a package substrate having an electrical connection structure, comprising: providing a package substrate body having at least one surface formed with an electrical connection pad, and forming an insulation protection layer on the package substrate body, the insulation protection layer Having an opening to expose a portion of the surface of the electrical connection pad; forming a plating adhesion layer on the exposed surface of the electrical connection pad; forming a conductive layer on the surface of the plating adhesion layer, the insulating protection layer and the opening thereof a resist layer is formed on the conductive layer, and a resist layer opening is formed in the resist layer corresponding to the position of the electrical connection pad, and the conductive layer on the insulating protective layer corresponding to the electrical connection pad and the periphery thereof is exposed; An electroplating process to form a metal layer on the conductive layer in the opening of the resist layer; and removing the resist layer and the conductive layer covered thereby to expose the metal layer.

According to the above method, a solder material is formed on the surface of the metal layer; or a surface treatment layer is formed on the upper surface of the metal layer, and a solder material is formed on the surface layer; or is included on the surface of the metal layer. And the side surface forms a surface treatment layer, and a solder material is formed on the outer surface of the surface treatment layer.

The plating adhesion layer is nickel/gold (Ni/Au, which is formed by nickel first, then gold is formed), nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), and nickel-palladium immersion gold (Electroless Nickel/Electroless) Palladium/Immersion Gold, ENEPIG), Immersion Tin, and Direct Immersion Gold (DIG); the solder material is tin-lead (Sn/Pb), tin-silver (Sn/) One of Ag), tin-silver-copper (Sn/Ag/Cu), tin-copper (Sn/Cu), tin (Sn), and low-melting solder of lead-free solder; the metal layer is copper (Cu), gold (Au ), one of silver (Ag) and high lead (high lead) high melting point metals.

In the package substrate with the electrical connection structure of the present invention and the method for fabricating the same, the surface of the electrical connection pad is first chemically deposited to form a subsequent layer, and then the metal layer is formed by electroplating on the subsequent layer. The affinity between the metal layer and the solder material is obtained by bonding the electrical connection pad and the metal layer by the plating adhesion layer and the solder material formed on the metal layer in the reflow process. And the high melting point non-melting property of the metal layer to restrict the flow of the liquid solder material, so that the solder material avoids overflow, thereby providing an electrical connection of the fine pitch package substrate; and by forming the electrical connection pad And plating the adhesion layer between the metal layers to improve the bonding strength between the electrical connection pad and the metal layer to prevent the solder material formed on the metal layer from falling off.

The other embodiments of the present invention will be readily understood by those skilled in the art from this disclosure.

2A to 2E are schematic cross-sectional views showing a method of manufacturing a package substrate having an electrical connection structure according to the present invention.

As shown in FIG. 2A, at least one package substrate body 20 having an electrical connection pad 200 formed thereon is provided as a two-layer or multi-layer package substrate having a completed circuit layout, wherein the electrical connection pad 200 can be borrowed. The inner layer line is electrically connected by a conductive blind hole (not shown).

An insulating protective layer 21 is formed on the package substrate body 20, and the insulating protective layer 21 is applied to the package substrate by any one of printing, spin coating and bonding, and the insulating protective layer 21 can be, for example, green. A solder resist material having a tin-reducing property such as lacquer is formed, and patterned by exposure, development, or the like to form the insulating protective layer 21 with an opening 210 exposing the electrical connection pad 200.

As shown in FIG. 2B, a plating adhesion layer 22 is formed on the exposed surface of the electrical connection pad 200; the plating adhesion layer 22 is made of nickel/gold (Ni/Au, which is formed by nickel first, then gold is formed). , Electroless Ni & Immersion Gold (ENIG), Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), Immersion Tin, and Direct Immersion Gold (Direct Immersion Gold, One of DIG).

As shown in FIG. 2C, a conductive layer 23 is formed on the upper surface of the plating resist layer 22, the upper surface of the insulating protective layer 21, and the surface of the opening 210 thereof. The conductive layer 23 is mainly used as a current required for plating a metal material to be described later. a conductive path, which may be composed of a metal, an alloy or a plurality of deposited metal layers, or a conductive polymer material may be used as the conductive layer 23; then a resist layer 24 is overlaid on the conductive layer 23 and patterned to resist Layer 24. The resist layer 24 can be a photoresist layer such as a dry film or a liquid photoresist, which is formed on the surface of the conductive layer 23 by printing, spin coating or lamination, and then exposed, developed, etc. The resist layer 24 is formed with a resist opening 240, and the resist opening 240 corresponds to the position of the electrical connection pad 200, and the resist opening 240 is larger than the opening 210. Thereby, the conductive layer 23 corresponding to the electrical connection pad 200 and a portion of the insulating protective layer 21 around the electrical connection pad 200 is exposed.

As shown in FIG. 2D, the package substrate is subjected to an electroplating process, and the conductive layer 23 is used as a current conduction path to form a metal layer 25 on the conductive layer 23 exposed in the resist layer opening 240. Wherein, the material of the metal layer 25 is one of copper (Cu), gold (Au), silver (Ag) and high lead (high lead) high melting point metal; however, according to practical experience, due to copper It is a mature electroplating material and has a low cost. Therefore, the metal layer 25 is preferably made of electroplated copper, but not limited thereto; then, a solder material 26 is formed on the surface of the metal layer 25, and the soldering is performed. Material 26 is a low melting point solder of tin-lead (Sn/Pb), tin-silver (Sn/Ag), tin-silver-copper (Sn/Ag/Cu), tin-copper (Sn/Cu), tin (Sn) and lead-free solder. One of them. Further, another form of the solder material 26 is formed by electroplating the metal layer 25 to form a solder material 26 on the surface of the metal layer 25.

As shown in FIG. 2E, the resist layer 24 and the conductive layer 23 covered thereby are removed to expose the metal layer 25 and the solder material 26.

Referring to FIGS. 3A and 3B, before the formation of the solder material 26, a surface treatment layer 27 is formed on the metal layer 25 by electroplating or chemical deposition, and then the solder material 26 is formed on the surface of the surface treatment layer 27. And then removing the resist layer 24 and the conductive layer 23 covered thereon, as shown in FIG. 3A; or removing the resist layer 24 and the conductive layer 23 covered thereby to expose the metal layer 25, and then The upper surface and the side surface of the metal layer 25 form a surface treatment layer 27', and then the exposed surface of the surface treatment layer 27' forms the solder material 26' as shown in Fig. 3B. Thereafter, the solder material 26, 26' is subjected to a reflow process and surface treatment layer 27, 27' to form a solder ball end structure for electrically connecting the package substrate to an external electronic device.

The present invention provides a package substrate having an electrical connection structure, comprising: a package substrate body 20 having a plurality of electrical connection pads 200 on at least one surface thereof, and an insulation protection on the surface and the electrical connection pads 200 The insulating layer 21 has an opening 210 corresponding to each of the electrical connection pads, and a portion of the surface of the electrical connection pad 200 is exposed; and the plating adhesion layer 22 is exposed outside the electrical connection pad 200. The metal layer 25 is disposed on the plating resist layer 22, the sidewall of the opening 210 of the insulating protective layer 21 of the insulating protective layer 21, and the surface of the insulating protective layer 21 on the outside of the opening 210.

According to the above structure, the upper surface of the plating resist layer 22, the sidewall of the opening 210 of the insulating protective layer 21, and the insulating protective layer 21 have a conductive layer 23 on the surface of the outside of the opening 210, and the conductive layer 23 is located. The lower surface of the metal layer 25.

Further, the upper surface of the metal layer 25 has a solder material 26 as shown in FIG. 2E; or a surface treatment layer 27 and a solder material 26 are sequentially provided on the metal layer 25 from bottom to top, as shown in FIG. 3A. Or a surface treatment layer 27' on the upper surface and the side surface of the metal layer 25, and the surface treatment layer 27' has a solder material 26 thereon, as shown in FIG. 3B.

The plating adhesion layer 22 is made of nickel/gold (Ni/Au, which is formed by first forming nickel, then gold is formed), nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), and nickel-palladium immersion gold (Electroless Nickel/ Electroless Palladium/Immersion Gold, ENEPIG), Immersion Tin, and Direct Immersion Gold (DIG).

The solder material 26 is low in tin-lead (Sn/Pb), tin-silver (Sn/Ag), tin-silver-copper (Sn/Ag/Cu), tin-copper (Sn/Cu), tin (Sn), and lead-free solder. One of the melting point solders.

The metal layer 25 is one of copper (Cu), gold (Au), silver (Ag), and high-lead high melting point metals.

Therefore, the method for manufacturing the package substrate with the electrical connection structure of the present invention is mainly to form a plating adhesion layer on the electrical connection pad by chemical deposition, and then on the plating adhesion layer, the opening sidewall of the insulation protection layer. And an insulating protective layer on the surface of the outside of the opening, through the conductive layer to form a metal layer by electroplating, so that the solder material formed on the upper surface of the metal layer is in the reflow process, and the metal layer is limited by the liquid solder material Flowing to avoid overflow of the solder material, thereby providing electrical connection of the fine pitch package substrate to avoid short circuit; and improving the electrical connection by forming the adhesive layer formed on the electrical connection pad and the metal layer The bonding strength between the pad and the metal layer prevents the solder material formed on the metal layer from falling off.

The above embodiments are intended to illustrate the principles of the invention and its effects, and are not intended to limit the invention. Any of the above-described embodiments may be modified by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the appended claims.

10. . . Package substrate

11, 21. . . Insulating protective layer

11a, 210. . . Opening

12,200. . . Electrical connection pad

15. . . Solder structure

20. . . Package substrate body

twenty two. . . Plating layer

twenty three. . . Conductive layer

twenty four. . . Resistance layer

240. . . Resistive layer opening

25. . . Metal layer

26, 26’. . . Welding materials

27, 27’. . . Surface treatment layer

C. . . corner

S. . . gap

1A and 1B are schematic cross-sectional views showing the formation of a solder material on an electrical connection pad of a package substrate; and FIGS. 2A to 2E are cross-sectional views showing a package substrate having an electrical connection structure of the present invention and a method of manufacturing the same; Fig. 3A is another embodiment of Fig. 2E; and Fig. 3B is still another embodiment of Fig. 2E.

20. . . Package substrate body

200. . . Electrical connection pad

twenty one. . . Insulating protective layer

twenty two. . . Plating layer

25. . . Metal layer

26. . . Welding materials

Claims (22)

A package substrate having an electrical connection structure includes: a package substrate body having a plurality of electrical connection pads on at least one surface thereof, and an insulating protection layer on the surface and the electrical connection pad, the insulation protection layer having a corresponding Opening a hole of each of the electrical connection pads, exposing a portion of the surface of the electrical connection pad; depositing an adhesive layer on the exposed surface of the electrical connection pad; and electrically conducting the layer on the plating adhesion layer The sidewall of the insulating protective layer and the insulating protective layer are on the surface of the periphery of the opening; and the metal layer is located on the conductive layer. The package substrate having an electrical connection structure according to claim 1, wherein the plating adhesion layer is a nickel/gold layer (Ni/Au), a nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), One of Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), Immersion Tin, and Direct Immersion Gold (DIG). A package substrate having an electrical connection structure according to claim 1 of the patent application, comprising a solder material, is located on an upper surface of the metal layer. A package substrate having an electrical connection structure according to claim 3, wherein the solder material is tin-lead (Sn/Pb), tin-silver (Sn/Ag), tin-silver-copper (Sn/Ag/Cu). One of the low melting point solders of tin-copper (Sn/Cu), tin (Sn) and lead-free solder. A package substrate having an electrical connection structure according to claim 1, wherein the metal layer is a high melting point metal of copper (Cu), gold (Au), silver (Ag), and high lead (High Lead). One of them. A package substrate having an electrical connection structure includes: a package substrate body having a plurality of electrical connection pads on at least one surface thereof, and an insulating protection layer on the surface and the electrical connection pad, the insulation protection layer having a corresponding Opening a hole of each of the electrical connection pads, exposing a portion of the surface of the electrical connection pad; depositing an adhesive layer on the exposed surface of the electrical connection pad; and the metal layer is on the plating adhesion layer The sidewall of the insulating protective layer and the insulating protective layer are on the surface of the periphery of the opening; the conductive layer is located on the plating subsequent layer, the sidewall of the insulating protective layer and the insulating protective layer are outside the opening The surface is located on the lower surface of the metal layer; and the surface treatment layer is located on the upper surface of the metal layer. The package substrate having an electrical connection structure according to claim 6, wherein the surface treatment layer is extended to the side surface of the metal layer. The package substrate having an electrical connection structure according to claim 6 , wherein the plating adhesion layer is a nickel/gold layer (Ni/Au), a nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), chemical immersion tin (Immersion Tin), and one of Direct Immersion Gold (DIG). The package substrate having an electrical connection structure according to claim 6, wherein the metal layer is a high melting point metal of copper (Cu), gold (Au), silver (Ag) and high lead (High Lead). One of them. The package substrate having an electrical connection structure according to the sixth aspect of the patent application, wherein the surface treatment layer is a nickel/gold layer (Ni/Au), a nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), One of Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), Immersion Tin (IT), and Direct Immersion Gold (DIG). A package substrate having an electrical connection structure according to claim 6 of the patent application, comprising a solder material, is disposed on the surface treatment layer. A package substrate having an electrical connection structure according to claim 11 wherein the solder material is tin-lead (Sn/Pb), tin-silver (Sn/Ag), tin-silver-copper (Sn/Ag/Cu). One of the low melting point solders of tin-copper (Sn/Cu), tin (Sn) and lead-free solder. A method for manufacturing a package substrate having an electrical connection structure, comprising: providing a package substrate body having at least one surface formed with an electrical connection pad, and forming an insulation protection layer on the package substrate body, the insulation protection layer having an opening Exposing a portion of the surface of the electrical connection pad; forming a plating adhesion layer on the exposed surface of the electrical connection pad; Forming a conductive layer on the plating adhesion layer, the insulating protective layer and the sidewalls thereof; forming a resist layer on the conductive layer, and forming a resist layer opening corresponding to the position of the electrical connection pad in the resist layer Corresponding to the conductive layer on the electrical connection pad and the insulating protective layer around it; performing an electroplating process to form a metal layer on the conductive layer in the opening of the resist layer; and removing the resist layer and the conductive layer covered thereby A layer to expose the metal layer. The method for manufacturing a package substrate having an electrical connection structure according to claim 13, wherein the plating adhesion layer is a nickel/gold layer (Ni/Au), and a nickel immersion gold (Electroless Ni & Immersion Gold, ENIG) ), one of Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), Immersion Tin, and Direct Immersion Gold (DIG). The method for manufacturing a package substrate having an electrical connection structure according to claim 13 of the patent application, comprising forming a solder material on an upper surface of the metal layer. The method for manufacturing a package substrate having an electrical connection structure according to claim 15, wherein the solder material is tin-lead (Sn/Pb), tin-silver (Sn/Ag), tin-silver-copper (Sn/Ag/). One of Cu, tin-copper (Sn/Cu), tin (Sn), and low-melting solders of lead-free solder. The method for manufacturing a package substrate having an electrical connection structure according to claim 13 , wherein the metal layer is copper (Cu), gold (Au), and silver. One of (Ag) and High Lead high melting point metals. The method for manufacturing a package substrate having an electrical connection structure according to claim 13 of the patent application, comprising forming a surface treatment layer on the upper surface of the metal layer. The method for manufacturing a package substrate having an electrical connection structure according to claim 13 of the patent application, comprising forming a surface treatment layer on the upper surface and the side surface of the metal layer. The method for manufacturing a package substrate having an electrical connection structure according to claim 18 or 19, wherein the surface treatment layer is a nickel/gold layer (Ni/Au) or a nickel immersion gold (Electroless Ni & Immersion Gold, ENIG), Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), Immersion Tin (IT), and Direct Immersion Gold (DIG). The method for manufacturing a package substrate having an electrical connection structure according to claim 18 or 19, further comprising forming a solder material on the surface treatment layer. The method for manufacturing a package substrate having an electrical connection structure according to claim 21, wherein the solder material is tin-lead (Sn/Pb), tin-silver (Sn/Ag), tin-silver-copper (Sn/Ag/ One of Cu, tin-copper (Sn/Cu), tin (Sn), and low-melting solders of lead-free solder.