TWI851135B - Fabricating method of carrier strucure - Google Patents

Abstract

A fabrication method of carrier structure is provided, in which a second insulating layer is formed on the outermost first insulating layer of a substrate body, so as to form conductive vias in the first insulating layer through the second insulating layer, and to form a conductive trace on the conductive vias, wherein a width of the conductive trace is smaller than a width of the conductive via. Therefore, it is facilitate to layout of more conductive traces on the first insulating layer, so as to effectively increase a wiring density and increase functions of an electronic product.

Description

Method of manufacturing load-bearing structure

The present invention relates to a semiconductor manufacturing process, in particular to a method for manufacturing a supporting structure for supporting a chip.

The technologies currently used in the chip packaging field include chip scale package (CSP), direct chip attached (DCA) or multi-chip module (MCM) packaging modules. As the functional requirements of end products increase, semiconductor chips need to have more input/output (I/O) contacts, so the number of pads outside the packaging substrate used to carry semiconductor chips also needs to increase accordingly.

FIG. 1 is a cross-sectional view of a conventional package substrate 1 . As shown in FIG1 , the package substrate 1 includes a core layer 10 having a first side 10a and a second side 10b opposite to each other, and the first side 10a and the second side 10b of the core layer 10 are respectively formed with a circuit structure 11, wherein the circuit structure includes a plurality of insulating layers 111 and a plurality of circuit layers 11a formed on each of the insulating layers 111, and the core layer 10 has a plurality of conductive through holes 100 connecting the first side 10a and the second side 10b to electrically connect the circuit layers 11a, and the circuit layers 11a are electrically connected through conductive blind holes 110, and an electrical contact pad 112 is provided on each of the conductive blind holes 110.

However, in the known package substrate 1, the width of the electrical contact pad 112 is greater than the width of the conductive blind hole 110, so that the electrical contact pad 112 occupies the surface of the insulating layer 111, which limits the layout space of the circuit layer 11a on the insulating layer 111, and is not conducive to the layout of a high-density circuit layer 11a, so it is difficult to increase the function of the electronic product.

Therefore, how to overcome the above-mentioned lack of knowledge and skills has become an urgent issue to be solved.

In view of the above-mentioned deficiencies of the prior art, the present invention provides a method for manufacturing a supporting structure, comprising: providing a substrate body, the outermost side of which is configured with a first insulating layer; forming a second insulating layer on the first insulating layer, and the second insulating layer is formed with at least one opening exposing the first insulating layer; forming a blind hole in the first insulating layer of the opening so that the first insulating layer The opening is connected to the blind hole; a portion of the material of the first insulating layer in the blind hole is removed so that the width of the opening is smaller than the width of the blind hole; and a conductive blind hole is formed in the blind hole, and a contact line is formed on the conductive blind hole in the opening so that the contact line is electrically connected to the conductive blind hole, wherein the width of the contact line is smaller than the width of the conductive blind hole.

In the aforementioned manufacturing method, a trench is formed on the second insulating layer to expose the first insulating layer, so as to form a conductive trace electrically connected to the contact line in the trench. For example, the surface of the conductive trace is lower than the surface of the second insulating layer.

In the aforementioned manufacturing method, the surface of the contact line is lower than the surface of the second insulating layer.

In the aforementioned manufacturing method, the width of the contact line and the width of the conductive blind hole differ by 3 microns.

In the aforementioned manufacturing method, part of the material of the first insulating layer in the blind hole is removed by a debonding process.

The aforementioned manufacturing method further includes forming a metal material on the second insulating layer and in the blind hole and the opening, and then removing the metal material on the second insulating layer so that the metal material in the blind hole serves as the conductive blind hole, and the metal material in the opening serves as the contact line. For example, the metal material on the second insulating layer is removed by etching. Furthermore, the etching method removes 4 to 6 microns of the thickness of the metal material.

In the aforementioned manufacturing method, the substrate body further includes a core layer having a first side and a second side opposite to each other, and at least one conductive through hole connecting the first side and the second side, so that the first insulating layer is formed on the first side and/or the second side of the core layer.

As can be seen from the above, the manufacturing method of the supporting structure of the present invention mainly makes the width of the contact line smaller than the width of the conductive blind hole, so that the contact line will not occupy the surface of the first insulating layer, so as to facilitate the layout of more conductive traces on the first insulating layer. Therefore, compared with the prior art, the present invention can effectively increase the wiring density, so as to facilitate the increase of the functions of electronic products.

1:Packaging substrate

10,20: Core layer

10a,20a: First side

10b,20b: Second side

100,200: Conductive vias

11: Circuit structure

11a,201,202: Circuit layer

110,240: Conductive blind vias

111: Insulation layer

112: Electrical contact pad

2: Load-bearing structure

2a: Substrate body

2b: Wiring layer

21: First insulating layer

210: Blind hole

22: Second insulation layer

220: Open mouth

221: Groove

23: Conductive layer

24:Metal material

25: Conductive traces

250: Contact line

D1,D2,R1,R2:Width

Figure 1 is a cross-sectional view of a conventional packaging substrate.

Figures 2A to 2E are cross-sectional schematic diagrams of the manufacturing method of the supporting structure of the present invention.

The following is a specific and concrete example to illustrate the implementation of the present invention. People familiar with this technology can easily understand other advantages and effects of the present invention from the content disclosed in this manual.

It should be noted that the structures, proportions, sizes, etc. depicted in the drawings attached to this specification are only used to match the contents disclosed in the specification for understanding and reading by people familiar with this technology, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effect and purpose that can be achieved by the present invention. At the same time, the terms such as "above", "first", "second", "one" etc. used in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships shall also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

Figures 2A to 2E are cross-sectional schematic diagrams of the manufacturing method of the supporting structure 2 of the present invention.

As shown in FIG. 2A , a substrate body 2a including a core layer 20 and a first insulating layer 21 is provided. The core layer 20 has a first side 20a and a second side 20b opposite to each other, and the first insulating layer 21 is disposed on the first side 20a and the second side 20b, respectively. Circuit layers 201 and 202 are disposed in the first insulating layer 21 on the first side 20a and the second side 20b of the core layer 20, respectively. Then, a second insulating layer 22 is formed on the outermost first insulating layer 21.

In this embodiment, the core layer 20 may be an organic polymer sheet or other sheet including Bismaleimide triazine (BT) and glass fiber prepreg (PP), and the core layer 20 has a plurality of conductive vias 200 connecting the first side 20a and the second side 20b, so that the conductive vias 200 are electrically connected to the circuit layers 201, 202. For example, the conductive vias 200 are solid metal columns in the shape of double cones with overlapping tips; or, the conductive vias may be hollow columns with the hollow filled with plugging materials (not shown), wherein the plugging materials are of various types, such as conductive glue, ink, etc., and are not particularly limited. It should be understood that the conductive via can have many shapes, such as a right cylinder, a single cone, or other geometric shapes, and there is no particular limitation.

Furthermore, the first insulating layer 21 is a dielectric layer, such as polybenzoxazole (PBO), polyimide (PI), glass fiber prepreg (PP) or other dielectric materials. It should be understood that a plurality of first insulating layers 21 can be respectively arranged on the first side 20a and the second side 20b of the core layer 20, and the wiring layers 201 and 202 electrically connected between the layers are arranged in each first insulating layer 21. In this embodiment, a single first insulating layer 21 is respectively arranged on the first side 20a and the second side 20b of the core layer 20 for explanation.

Furthermore, the second insulating layer 22 is a photosensitive imaging layer, and the second insulating layer 22 is formed with a plurality of openings 220 and trenches 221 that expose the first insulating layer 21. For example, the opening 220 corresponds to the position of each of the conductive vias 200.

In addition, there are many types of substrate bodies 2a, such as coreless circuit structures, silicon interposers, or other carrier units that can carry electronic components such as chips, but are not limited to the above.

As shown in FIG. 2B , a plurality of blind holes 210 are formed on the outermost first insulating layer 21 in each of the openings 220 by laser or other methods, so that the openings 220 are connected to the blind holes 210 , so that the pad surface of the conductive via 200 is exposed to the openings 220 and the blind holes 210 .

As shown in FIG. 2C , part of the material of the first insulating layer 21 in the blind hole 210 is removed so that the width (aperture) D1 of the opening 220 is smaller than the width (aperture) D2 of the blind hole 210 .

In this embodiment, the insulating material on the wall of the blind hole 210 is removed by a desmear process to enlarge the diameter of the blind hole. For example, the width D1 of the opening 220 and the width D2 of the blind hole 210 differ by about 3 micrometers (um).

As shown in FIG. 2D , a conductive layer 23 is formed on the second insulating layer 22, the wall surface of the opening 220, the wall surface of the trench 221, and the wall surface of the blind hole 210. Then, a metal material 24 is formed on the conductive layer 23 so that the metal material 24 is filled into the blind holes 210, the opening 220, and the trench 221, so that the metal material 24 in the blind hole 210 and the conductive layer 23 serve as a conductive blind hole 240.

In this embodiment, the conductive blind hole 240 is electrically connected to the conductive through hole 200, and the metal material 24 is copper. For example, the metal material 24 is formed by electroplating or other methods.

As shown in FIG. 2E , the conductive layer 23 on the second insulating layer 22 and the metal material 24 thereon are removed, so that the metal material 24 and the conductive layer 23 in each of the grooves 221 serve as the conductive trace 25, and the metal material 24 and the conductive layer 23 in the openings 220 serve as the contact line 250 electrically connecting the conductive blind hole 240 and the conductive trace 25, so that the conductive trace 25, the conductive blind hole 240 and the contact line 250 serve as the wiring layer 2b.

In this embodiment, a rapid etching process is used to remove the metal material 24 so that the conductive trace 25 and the contact line 250 are recessed into the groove 221 and the opening 220, so that the surface of the conductive trace 25 and the surface of the contact line 250 are lower than the surface of the second insulating layer 22. The rapid etching refers to etching only a small amount of the metal material 24, such as stopping the etching when the etching thickness is 4-6 microns.

Furthermore, when the metal material 24 is removed, the second insulating layer 22 serves as a barrier layer, and in the subsequent process, the second insulating layer 22 serves as a solder mask so that the solder material can be bonded to the conductive trace 25 or the contact line 250 for re-welding.

Therefore, the manufacturing method of the supporting structure 2 of the present invention mainly uses the landless design of the outermost conductive blind hole 240 to make the width R1 of the contact line 250 smaller than the width R2 of the conductive blind hole 240, so that the contact line 250 will not occupy the surface of the first insulating layer 21, so as to facilitate the layout of more conductive traces 25 on the first insulating layer 21. Therefore, compared with the prior art, the manufacturing method of the present invention can effectively increase the wiring density of the wiring layer 2b of the supporting structure 2, so as to facilitate the increase of the function of the electronic product.

The above embodiments are used to illustrate the principles and effects of the present invention, but are not used to limit the present invention. Anyone familiar with this technology can modify the above embodiments without violating the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be as listed in the scope of the patent application described below.

2: Load-bearing structure

2a: Substrate body

2b: Wiring layer

20: Core layer

20a: First side

20b: Second side

200: Conductive vias

201,202: Circuit layer

21: First insulating layer

22: Second insulation layer

210: Blind hole

220: Open mouth

221: Groove

240: Conductive blind vias

25: Conductive traces

250: Contact line

R1, R2: Width

Claims (10)

A method for manufacturing a load-bearing structure, comprising: A substrate body is provided, the outermost side of which is provided with a first insulating layer; A second insulating layer is formed on the first insulating layer, and the second insulating layer is formed with at least one opening exposing the first insulating layer; Form a blind hole in the first insulating layer of the opening so that the opening is connected to the blind hole; Remove part of the material of the first insulating layer in the blind hole so that the width of the opening is smaller than the width of the blind hole; and A conductive blind hole is formed in the blind hole, and a contact line is formed on the conductive blind hole in the opening, so that the contact line is electrically connected to the conductive blind hole, wherein the width of the contact line is smaller than the width of the conductive blind hole. The method for manufacturing a supporting structure as described in claim 1, wherein a groove is formed on the second insulating layer to expose the first insulating layer, so as to form a conductive trace electrically connected to the contact line in the groove. A method for manufacturing a supporting structure as described in claim 2, wherein the surface of the conductive trace is lower than the surface of the second insulating layer. A method for manufacturing a load-bearing structure as described in claim 1, wherein the surface of the contact line is lower than the surface of the second insulating layer. A method for manufacturing a supporting structure as described in claim 1, wherein the width of the contact line and the width of the conductive blind hole differ by 3 microns. A method for manufacturing a supporting structure as described in claim 1, wherein a portion of the material of the first insulating layer in the blind hole is removed by a debonding process. The method for manufacturing the supporting structure as described in claim 1 further includes forming metal material on the second insulating layer and in the blind hole and the opening, and then removing the metal material on the second insulating layer to make the metal material in the blind hole serve as the conductive blind hole, and the metal material in the opening serve as the contact line. A method for manufacturing a supporting structure as described in claim 7, wherein the metal material on the second insulating layer is removed by etching. The method for manufacturing a supporting structure as described in claim 8, wherein the etching method removes 4 to 6 microns of the thickness of the metal material. A method for manufacturing a supporting structure as described in claim 1, wherein the substrate body further comprises a core layer having a first side and a second side opposite to each other, and at least one conductive through hole connecting the first side and the second side, so that the first insulating layer is formed on the first side and/or the second side of the core layer.

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