TWI813580B - Printed circuit board - Google Patents

Abstract

According to an aspect of the present invention, there is provided a printed circuit board comprising: an insulating layer of which a metal pad is embedded in the lower surface; an opening part penetrating the insulating layer and formed on the upper surface of the metal pad; a metal bump formed in the opening part and having the upper surface protruding above the upper surface of the insulating layer; and a conductive member formed on the lower surface of the metal pad, wherein a melting point of the conductive member is lower than that of the metal bump, wherein the lower surface of the metal pad is recessed more than the lower surface of the insulating layer.

Description

printed circuit board

The following instructions are for a printed circuit board.

The methods of manufacturing printed circuit boards include parallel build up lamination and sequential lamination. Parallel build-up lamination involves high-temperature pressing, while incremental build-up involves low-temperature pressing. When a parallel structure stacking method is adopted, paste can be used as the inter-unit layer connection structure. In this case, the adhesion and connectivity between the internal wiring and the paste may deteriorate.

Japanese Patent Publication No. 2003-179356 describes an example of a printed circuit board.

The object of the present invention is to provide a printed circuit board with excellent interlayer adhesion.

According to an aspect of the present invention, a printed circuit board is provided, which includes: an insulating layer with a metal pad embedded in the lower surface of the insulating layer; an opening portion passing through the insulating layer and formed on the upper surface of the metal pad; a metal bump formed in the opening portion and having an upper surface protruding above an upper surface of the insulating layer; and a conductive member shaped formed on the lower surface of the metal pad, wherein the melting point of the conductive component is lower than the melting point of the metal bump, and the lower surface of the metal pad is recessed beyond the lower surface of the insulating layer.

According to another aspect of the present invention, a printed circuit board is provided, which includes: a first insulating layer with a first metal pad embedded in its lower surface; a first opening portion passing through the first insulating layer and formed in on the upper surface of the first metal pad; a first metal bump formed in the first opening portion; a second insulating layer stacked on the first insulating layer and formed on the first metal bump; and a conductive member, Formed on the lower surface of the second metal pad and contacting the side surface of the first metal bump.

10, 20, 30: unit substrate

100, 200: Insulation layer

110, 210: Metal pad

110’, 111’: space

111, 211: Circuit

120, 220: opening part

130, 230: Metal bumps

131, 231: High melting point bumps

132, 232: Low melting point bumps

300:dent

P1, P2, P3, P4: conductive components

C0: Insulating material

C1: Carrier metal foil

C2: Seed metal foil

R: Resist film

M: mask

Figure 1 shows a printed circuit board according to a first embodiment of the invention.

Figure 2 shows a printed circuit board according to a second embodiment of the invention.

Figure 3 shows a printed circuit board according to a third embodiment of the invention.

Figure 4 shows a printed circuit board according to a fourth embodiment of the invention.

Figure 5 shows a printed circuit board according to a fifth embodiment of the invention.

6 to 9 are cross-sectional views illustrating various processes used in a method of manufacturing a printed circuit board according to an embodiment of the present invention.

10 to 11 are cross-sectional views illustrating various processes used in a method of manufacturing a printed circuit board according to another embodiment of the present invention.

12 to 14 are cross-sectional views illustrating various processes used in a method of manufacturing a printed circuit board according to yet another embodiment of the present invention.

Throughout the drawings and detailed description, the same reference numbers refer to the same element. The drawings may not be drawn to scale, and the relative sizes, proportions, and illustrations of elements in the drawings may be exaggerated for clarity, illustration, and convenience.

The following detailed description is provided to assist the reader in obtaining a comprehensive understanding of the methods, apparatus, and/or systems described herein. However, various modifications, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent to those of ordinary skill in the art. The sequences of operations described herein are examples only, and are not limited to those mentioned herein, but as will be apparent to one of ordinary skill in the art, except for operations that necessarily occur in a specific order. Other than that, it can be changed. In addition, descriptions of functions and constructions that are well known to those of ordinary skill in the art may be omitted to enhance clarity and clarity.

Features described herein may be implemented in different forms and should not be construed as limited to the examples set forth herein. Rather, the examples described herein are provided so that this disclosure will be thorough and complete, and will convey the full scope of the invention to those skilled in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Any term defined in a commonly used dictionary shall be construed to have the same meaning as in the context of the relevant technology and shall not be construed to have an idealized or overly formal meaning unless otherwise expressly defined.

Regardless of the figure number, the same or corresponding components will be given the same reference numbers and will not be described again. Throughout the description of the present invention, when specific related conventional techniques are described that are determined to be irrelevant to the viewpoint of the present invention, the relevant detailed description will be omitted. Terms such as "first" and "second" may be used when describing various components, but the above components should not be limited to the above terms. The above terms are only used to distinguish between the various components. In the drawings, some components may be exaggerated, omitted, or simplified, and the sizes of components do not necessarily reflect the actual sizes of the components.

Hereinafter, specific embodiments of the invention will be explained in detail with reference to the accompanying drawings.

Figure 1 shows a printed circuit board according to a first embodiment of the invention.

Referring to FIG. 1 , a printed circuit board according to a first embodiment of the present invention includes an insulating layer 100 with metal pads 110 formed thereon, an opening portion 120 formed in the insulating layer 100 , a metal bump formed in the opening portion 120 and The conductive member P1 is formed on the lower surface of the metal pad 110 .

The insulating layer 100 is made of an insulating material such as resin. The resin of the insulating layer 100 may be made of various materials such as thermosetting resin and thermoplastic resin.

The insulating layer 100 may be made of a material with low dielectric constant (Dk) and low dielectric loss (Df). Specifically, the insulating layer 100 can be made of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyphenylene ether (PPE), cyclo olefin polymer (COP) and polyfluoroalkoxy (PFA) At least one of them is formed. This material is suitable for reducing signal losses in substrates used to transmit high-frequency signals.

However, the insulating layer 100 is not limited to the above materials, and may be formed of epoxy resin, polyimide, or the like. Examples of epoxy resins include naphthalene epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac epoxy Novolac epoxy resin, cresol novolak epoxy resin, rubber modified epoxy resin, cycloaliphatic epoxy resin, silicone epoxy Resin (silicon-based epoxy resin), nitrogen-based epoxy resin (nitrogen-based epoxy resin), phosphorus-based epoxy resin (phosphorus-based epoxy resin), etc. However, it is not limited to this.

The insulation layer 100 may be a prepreg (PPG) containing fiber reinforcement material such as glass cloth in resin. The insulating layer 100 may be a film composed of resin filled with an inorganic filler such as silica. Ajinomoto build-up film (ABF) or the like can be used as such a build-up film.

The insulating layer 100 may be formed of a photosensitive material such as photoimageable dielectric (PID).

Circuits 111 and metal pads 110 are formed on the insulating layer 100 . Specifically, the circuit 111 and the metal pad 110 may be embedded in the lower surface of the insulating layer 100 . Circuit 111 is a conductor patterned to transmit electrical signals. The metal pad 110 is connected A conductor connected to the end of circuit 111. The circuit 111 and the metal pad 110 are made of metals such as copper (Cu), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), platinum (Pt) or alloys thereof. .

The lower surface of the metal pad 110 is recessed beyond the lower surface of the insulating layer 100 . The lower surface of the metal pad 110 enters the inside of the insulating layer 100 compared to the lower surface of the insulating layer 100 . Therefore, a step-height is formed between the lower surface of the metal pad 110 and the lower surface of the insulating layer 100, and the lower surface of the metal pad 110 and the insulating layer 100 provide a predetermined space (see 110 in FIG. 7 ').

The lower surface of the circuit 111 may also be recessed beyond the lower surface of the insulating layer 100 . That is, the lower surface of the circuit 111 enters the inside of the insulating layer 100 than the lower surface of the insulating layer 100 . Therefore, a step height is formed between the lower surface of the circuit 111 and the lower surface of the insulating layer 100, and the lower surface of the circuit 111 and the insulating layer 100 may provide a predetermined space (see 111' in FIG. 7).

The opening portion 120 is formed in the insulating layer 100 . The opening portion 120 is formed through the insulating layer 100 to be located on the upper surface of the metal pad 110 . The opening portion 120 is formed on the upper surface of the metal pad 110 so that at least a portion of the upper surface of the metal pad 110 is exposed through the opening portion 120 . The opening portion 120 may be formed in a cylindrical shape.

Metal bumps 130 are formed in the opening portion 120 . The upper surface of the metal bump 130 may protrude above the upper surface of the insulating layer 100 .

Metal bumps 130 may be formed in two layers. In this case, the metal bumps 130 may include high melting point bumps 131 and low melting point bumps 132 . High melting point bump 131 The low melting point bumps 132 are bumps made of metal with a relatively higher melting point than the low melting point bumps 132 , and the low melting point bumps 132 are bumps made of metal with a relatively lower melting point than the high melting point bumps 131 . For example, the high melting point bump 131 may be made of a metal including copper, and the low melting point bump 132 may be made of a metal including tin, respectively.

The low melting point bump 132 may be located above the high melting point bump 131 , and the thickness of the low melting point bump 132 may be smaller than the thickness of the high melting point bump 131 . The upper surface of the high melting point bump 131 may be located below the upper surface of the insulating layer 100 , and the upper surface of the low melting point bump 132 may be located above the upper surface of the insulating layer 100 . That is, the upper surface of the metal bump 130 protrudes above the upper surface of the insulating layer 100 , and the interface between the high melting point bump 131 and the low melting point bump 132 may be located below the upper surface of the insulating layer 100 .

The conductive member P1 is formed on the lower surface of the metal pad 110 , and the lower surface of the metal pad 110 is recessed beyond the lower surface of the insulating layer 100 . That is, the conductive member P1 may be formed in the space 110' formed by the lower surface of the metal pad 110 and the insulating layer 100. The conductive member P1 may be formed by a step height between the lower surface of the metal pad 110 and the lower surface of the insulating layer 100 . In this case, the lower surface of the conductive member P1 may be located on the same plane as the lower surface of the insulating layer 100 .

The conductive member P1 may include metals such as copper (Cu), tin (Sn), and silver (Ag). Specifically, the conductive member P1 may be a paste containing metal. However, it is not limited to these materials. Any material that is electrically conductive can be used. The metal forming the conductive member P1 may be the same metal as the metal forming the low melting point bump 132 .

The melting point of the conductive member P1 may be lower than the melting point of the metal pad 110 , may be lower than the melting point of the high melting point bump 131 , and may be equal to or lower than the melting point of the low melting point bump 132 . point.

The conductive member P1 may be further formed on a lower surface of the circuit 111 that is recessed beyond the lower surface of the insulating layer 100 . That is, the conductive member P1 may be formed in the space 111' formed by the lower surface of the circuit 111 and the insulating layer 100. The conductive member P1 may be formed by a step height between the lower surface of the circuit 111 and the lower surface of the insulating layer 100 . In this case, the lower surface of the conductive member P1 may be located on the same plane as the lower surface of the insulating layer 100 .

The printed circuit board according to the first embodiment of the present invention may be a multi-layer printed circuit board. The multilayer printed circuit board includes a plurality of insulating layers 100 and 200, circuits 111 and 211, metal pads 110 and 210, openings 120 and 220, metal bumps 130 and 230, conductive members P1 and P2, etc. This will be elaborated upon.

The printed circuit board according to the first embodiment of the present invention may include a first insulating layer 100 with a first metal pad 110 formed thereon, a second insulating layer 200 with a second metal pad 210 formed thereon, the insulating layer 100 The first opening part 120 formed in the second insulating layer 200 , the first metal bump 130 formed in the first opening part 120 , the second opening part 220 formed in the second opening part 220 The metal bump 230 and the conductive member P2 formed on the lower surface of the second metal pad 210 .

The first insulation layer 100 and the second insulation layer 200 are the same as the above-mentioned insulation layers. The first insulation layer 100 and the second insulation layer 200 may be formed of the same material, and the second insulation layer 200 may be stacked on the first insulation layer 100 .

The first circuit 111 and the first metal pad 110 are embedded in the first insulating layer 100 in the lower surface. In addition, the second circuit 211 and the second metal pad 210 are embedded in the lower surface of the second insulating layer 200 . Therefore, the lower surface of the second circuit 211 and the lower surface of the second metal pad 210 are located at the interface between the first insulating layer 100 and the second insulating layer 200 .

The lower surface of the second metal pad 210 is recessed beyond the lower surface of the second insulating layer 200 . The lower surface of the second metal pad 210 enters the inside of the second insulating layer 200 compared to the lower surface of the second insulating layer 200 . Therefore, a step height is formed between the lower surface of the second metal pad 210 and the lower surface of the second insulating layer 200 . The lower surface of the metal pad 210 and the second insulating layer 200 provide a predetermined space.

The lower surface of the second circuit 211 may also be recessed beyond the lower surface of the second insulating layer 200 . That is, the lower surface of the second circuit 211 enters the inside of the second insulating layer 200 than the lower surface of the second insulating layer 200 . Therefore, a step height is formed between the lower surface of the second circuit 211 and the lower surface of the second insulating layer 200 . The lower surface of the second circuit 211 and the second insulation layer 200 provide a predetermined space.

If necessary, the lower surface of the first metal pad 110 may be recessed beyond the lower surface of the first insulating layer 100 . The lower surface of the first metal pad 110 enters the inside of the first insulating layer 100 compared to the lower surface of the first insulating layer 100 . Therefore, a step height is formed between the lower surface of the first metal pad 110 and the lower surface of the first insulating layer 100 . The lower surface of the first metal pad 110 and the first insulating layer 100 provide a predetermined space.

The lower surface of the first circuit 111 may also be recessed beyond the lower surface of the first insulating layer 100 . That is, the lower surface of the first circuit 11 enters the inside of the first insulating layer 100 than the lower surface of the first insulating layer 100 . On the lower surface of the first circuit 111 and A step height is formed between the lower surfaces of the first insulating layer 100 , and a predetermined space is provided between the lower surface of the first circuit 111 and the first insulating layer 100 .

The first opening portion 120 is formed on the upper surface of the first metal pad 110 through the first insulating layer 100, and the second opening portion 220 is formed on the upper surface of the second metal pad 210 through the second insulating layer 200. . The first opening part 120 and the second opening part 220 are provided to overlap each other. The fact that the first opening portion 120 and the second opening portion 220 overlap each other means that the first opening portion 120 and the second opening portion 220 overlap each other when virtually projected on the same plane. Preferably, the first opening part 120 and the second opening part 220 may be arranged in a row so that the center of the first opening part 120 and the center of the second opening part 220 coincide with each other.

The first metal bump 130 is formed in the first opening part 120 , and the second metal bump 230 is formed in the second opening part 220 . The first metal bump 130 and the second metal bump 230 are no different from the above-mentioned metal bumps. When the first opening portion 120 and the second opening portion 220 are formed to overlap each other, the first metal bump 130 and the second metal bump 230 are also formed to overlap each other.

The conductive member P2 may be formed on the lower surface of the second metal pad 210 to perform interlayer bonding. This is no different from the conductive member P1 described above.

That is, the melting point of the conductive member P2 may be lower than the melting point of the second metal pad 210 , lower than the melting point of the high melting point bump 231 , and equal to or lower than the melting point of the low melting point bump 232 .

The conductive member P2 may include metals such as copper (Cu), tin (Sn), and silver (Ag), and specifically, the conductive member P2 may be a metal-containing paste. However, The material is not limited to these materials, and any material having conductivity may be used. The metal contained in the conductive member P2 may be the same as the metal contained in the low melting point bump 232 .

The conductive member P2 may be formed on the lower surface of the second metal pad 210 , and the lower surface of the second metal pad 210 is recessed beyond the lower surface of the second insulating layer 200 . The first metal bump 130 protrudes beyond the upper surface of the first insulation layer 100 , and the protruding upper portion of the first metal bump 130 may be recessed into the conductive member P2 formed on the lower surface of the second metal pad 210 . The conductive member P2 may thus contact the side surface of the first metal bump 130 . An intermetallic compound (IMC) is formed in a region where the conductive member P2 and the first metal bump 130 are in contact with each other.

The conductive member P2 is formed on the entire lower surface of the second metal pad 210 so that the conductive member P2 can be disposed between the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 and the first metal on the side surface of the bump 130.

The bonding structure composed of metal bumps and conductive members can be repeatedly formed in multiple insulating layers. In other words, although the first insulating layer 100 and the second insulating layer 200 are described in the above description, the printed circuit board may include three or more insulating layers. This also applies to at least two insulation layers adjacent to each other.

The conductive member P1 may be formed on the lower surface of the first metal pad 110 , and the lower surface of the first metal pad 110 is recessed beyond the lower surface of the first insulating layer 100 . Such a conductive member P1 may be disposed on a metal bump of another insulating layer stacked below the first insulating layer 100 .

If necessary, the conductive members P3 and P4 may also be formed on the first circuit 111 on the lower surface and on the lower surface of the second circuit 211 . The conductive members P3 and P4 may be formed on all or part of the lower surfaces of the circuits 111 and 211 .

Figure 2 shows a printed circuit board according to a second embodiment of the invention.

2 , a printed circuit board according to a second embodiment of the present invention includes a first insulating layer 100 with a first metal pad 110 formed thereon, a second insulating layer 200 with a second metal pad 210 formed thereon, and a second insulating layer 200 formed with a second metal pad 210 formed thereon. The first opening part 120 in the first insulating layer 100, the second opening part 220 formed in the second insulating layer 200, the first metal bump 130 formed in the first opening part 120, the second opening part 130 formed in the second opening part 220 and the conductive member P2 formed on the lower surface of the second metal pad 210 .

In the printed circuit board according to the second embodiment of the present invention, the conductive member P2 contacts a predetermined area or more areas of the side surface of the first metal bump 130 . Here, the conductive member P2 surrounds a part or the entire part of the side surface of the first metal bump 130 . The "predetermined area" may be an area where the first metal bump 130 is located in the space defined by the lower surface of the second metal pad 210 and the lower surface of the second insulating layer 200 . That is, the conductive member P2 may contact the side surface of the first metal bump 130 beyond the boundary between the first insulation layer 100 and the second insulation layer 200 . Specifically, when there is a gap between the first insulating layer 100 and the side surface of the first metal bump 130 and the first insulating layer 100 and the second insulating layer 200 are pressed and stacked, the conductive member P2 may flow into the gap. And therefore, the conductive member P2 may cover the entire predetermined area or more areas of the side surface of the first metal bump 130 . Preferably, the conductive member P2 may cover the entire first metal bump 130 . Formed in the area where the conductive member P2 and the first metal bump 130 contact each other There are intermetallic compounds (IMC). The larger the contact area between the conductive member P2 and the first metal bump 130, the stronger the adhesion.

In addition, there may be a region in the second metal pad 210 where the conductive member P2 is not formed. The conductive member P2 may not be formed in areas other than the central area where the first metal bump 130 contacts the lower surface of the second metal pad 210 . However, in the second embodiment, it is not excluded that the conductive member P2 is formed on the entire lower surface of the second metal pad 210 as shown in FIG. 4 .

If necessary, the conductive member P2 can be prevented from being located between the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 by changing the stacking conditions of the first insulating layer 100 and the second insulating layer 200 . That is, the upper surface of the first metal bump 130 may contact the lower surface of the second metal pad 210 .

For example, if the volume of the gap is large or the pressure of the side of the first metal bump 130 facing the second metal pad 210 is relatively high, then the owner of the conductive member P2 flows into the gap, and the conductive member P2 may not be located on the first side. between the upper surface of the metal bump 130 and the lower surface of the second metal pad 210 . Here, the contact area between the conductive member P2 and the lower surface of the second metal pad 210 may be equal to the thickness of the conductive member P2.

The upper surface of the first metal bump 130 contacts the lower surface of the second metal pad 210 , and the conductive member P2 may be formed on the lower surface of the second metal pad 210 except for the area in contact with the first metal bump 130 parts. That is, the conductive member P2 may be formed on the lower surface of the second metal pad 210 that does not contact the first metal bump 130 .

Figure 3 shows a printed circuit board according to a third embodiment of the invention.

Referring to Figure 3, a printed circuit board according to a third embodiment of the present invention includes an upper The first insulating layer 100 with the first metal pad 110 formed on the surface, the second insulating layer 200 with the second metal pad 210 formed on the surface, the first opening portion 120 formed in the first insulating layer 100, the The second opening part 220 in the second insulating layer 200, the first metal bump 130 formed in the first opening part 120, the second metal bump 230 formed in the second opening part 220 and the second metal connection Conductive member P2 on the lower surface of pad 210 .

In the printed circuit board according to the third embodiment of the present invention, the conductive member P2 may extend to the side surface of the second metal pad 210 to cover the side surface of the second metal pad 210 . When there is a gap between the second metal pad 210 and the second insulating layer 200, this may be a result of the conductive member P2 flowing into the gap.

The conductive member P2 may cover a predetermined area or more areas of the side surface of the first metal bump 130 and also cover the side surface of the second metal pad 210 . In addition, the conductive member P2 may be continuously formed from the side surface of the first metal bump 130 to the side surface of the second metal pad 210 . An intermetallic compound (IMC) is formed in the area where the conductive member P2 contacts the first metal bump 130 and the second metal pad 210 . The larger the contact area between the conductive member P2 and the first metal bump 130, the stronger the adhesion.

If necessary, the conductive member P2 can be prevented from being located between the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 by changing the stacking conditions of the first insulating layer 100 and the second insulating layer 200 . That is, the upper surface of the first metal bump 130 may contact the lower surface of the second metal pad 210 . For example, if the volume of the gap is large or the pressure of the first metal bump 130 toward the second metal pad 210 is relatively high, the owner of the conductive member P2 flows into the gap, and the conductive member P2 can It is not located between the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 .

Figure 4 shows a printed circuit board according to a fourth embodiment of the invention.

4 , a printed circuit board according to a fourth embodiment of the present invention includes a first insulating layer 100 with a first metal pad 110 formed thereon, a second insulating layer 200 with a second metal pad 210 formed thereon, and a second insulating layer 200 formed with a second metal pad 210 formed thereon. The first opening part 120 in the first insulating layer 100, the second opening part 220 formed in the second insulating layer 200, the first metal bump 130 formed in the first opening part 120, the second opening part 130 formed in the second opening part 220 and the conductive member P2 formed on the lower surface of the second metal pad 210 .

In the printed circuit board according to the fourth embodiment of the present invention, the metal bump 130 may be formed as a single layer. In this case, the metal bump 130 may be made of metal such as copper. That is, the first metal bump 130 and the second metal bump 230 may each be formed as a single layer.

In this case, the position of the conductive member P2 is not limited to that shown in FIG. 4 , but may be replaced with the position of the conductive member P2 described in the first to third embodiments.

Figure 5 shows a printed circuit board according to a fifth embodiment of the invention.

Referring to FIG. 5 , a printed circuit board according to a fifth embodiment of the present invention includes an insulating layer 100 with metal pads 110 formed thereon, an opening portion 120 formed in the insulating layer 100 , and a metal bump 130 formed in the opening portion 120 and a conductive member P1 formed on the lower surface of the metal pad 110 . In addition, the lower surface of the metal pad 110 A depression is formed on the substrate, and the conductive member P1 is filled in the depression.

A multilayer printed circuit board according to the fifth embodiment of the present invention includes a first insulating layer 100 with a first metal pad 110 formed thereon, a second insulating layer 200 with a second metal pad 210 formed thereon, and a first insulating layer 100 formed with a first metal pad 110 formed thereon. The first opening part 120 in the insulating layer 100, the second opening part 220 formed in the second insulating layer 200, the first metal bump 130 formed in the first opening part 120, the first metal bump 130 formed in the opening part 220. The two metal bumps 230 and the conductive member P2 formed on the lower surface of the second metal pad 210 . A depression 300 may be formed on the lower surface of the second metal pad 210 , and the cross-sectional area of the depression 300 may be smaller than the cross-sectional area of the second metal pad 210 . The conductive member P2 is filled in the recess 300 . The first metal bump 130 may be inserted into the recess 300 .

In FIG. 5 , the first metal bump 130 is formed into a two-layer structure, but the fifth embodiment does not exclude the first metal bump 130 having a single-layer structure.

When a gap exists between the first metal bump 130 and the first insulation layer 100 , the conductive member P2 flows into the gap to cover a predetermined area or more areas of the side surface of the first metal bump 130 .

On the other hand, depending on conditions such as the flow distance of the conductive member P2, the volume of the gap, the lamination pressure, etc., the conductive member P2 may move beyond the recess 300 to reach the lower surface (not shown) of the second metal pad 210. In addition, when there is a gap between the second metal pad 210 and the second insulating layer 200 , the conductive member P2 may flow into the gap to cover the side surface of the second metal pad 210 (not shown).

In the following, a method of manufacturing a printed circuit board will be explained.

6 to 9 are cross-sectional views illustrating various processes used in a method of manufacturing a printed circuit board according to an embodiment of the present invention.

Referring to FIG. 6 , a carrier in which metal foils are laminated on both surfaces of an insulating material C0 is provided. The insulating material C0 may be prepreg or the like. The metal foil may be formed on each side of the insulating material CO in a two-layer structure, and the two-layer structure may be a copper layer. The metal foil in contact with both surfaces of the insulating material C0 may be a carrier metal foil C1 with a thickness of 18 microns (μm), and the metal foil laminated on the carrier metal foil C1 may be a seed metal foil with a thickness of 5 μm. C2.

In FIG. 6 , only one surface of the insulating material C0 is shown from the second step, but the same process can be performed on both surfaces of the insulating material C0 .

Referring to FIG. 6 , a resist film R is coated on the metal foil, and the resist film R is patterned through a photolithography process including exposure and development. The circuit 111 and the metal pad 110 are patterned by performing pattern plating. Pattern plating can be performed by electrolytic plating, in which electrons move through a metal foil of a carrier.

The resist film R is removed, and the insulating layer 100 is stacked on the carrier. The insulating layer 100 may be made of LCP, epoxy resin, PID, or the like.

An opening portion 120 is formed in the insulating layer 100 , and the opening portion 120 is located on the metal pad 110 . The upper surface of the metal pad 110 is exposed through the opening portion 120 . When the insulating layer 100 is photosensitive, the opening portion 120 can be formed through exposure and development processes. On the other hand, when the insulating layer 100 is non-photosensitive, the opening portion 120 can be formed by a laser process.

FIG. 7 illustrates the process associated with FIG. 6 .

Referring to FIG. 7 , after desmear is performed to remove residue (smear) in the opening portion 120 , the metal bump 130 is formed in the opening portion 120 . The metal bump 130 is formed to protrude above the upper surface of the insulating layer 100 . When the metal bumps 130 are formed into a two-layer structure, the high melting point bumps 131 are formed first, and the relatively thin low melting point bumps 132 are formed on the high melting point bumps 131 . The high melting point bumps 131 and the low melting point bumps 132 can be formed by electrolytic plating. In this case, the electrons move through the metal foil of the carrier.

A mask M is stacked on the insulating layer 100, and the mask M can protect the metal bumps 130 in an etching process to be described later.

After the mask M is formed on the insulating layer 100, the carrier is removed. Only a portion of the metal foil of the carrier (especially the seed metal foil C2 ) remains, and the seed metal foil C2 can be removed by a separate etching process. Here, when the metal pad 110 and the seed metal foil C2 are formed of the same metal, the lower surface of the metal pad 110 and the seed metal foil C2 are etched together. As a result, the lower surface of the metal pad 110 is recessed beyond the lower surface of the insulating layer 100, and the lower surface of the metal pad 110 and the insulating layer 100 form a space 110'.

Similar to the lower surface of the metal pad 110, the lower surface of the circuit 111 is etched together with the seed metal foil C2. As a result, the lower surface of the circuit 111 is recessed beyond the lower surface of the insulating layer 100 . The lower surface of the circuit 111 and the insulating layer 100 form a space 111'.

A conductive member P1 is formed on the lower surface of the metal pad 110, and conductive The component P1 is printed (filled) in the space 110' formed by the lower surface of the metal pad 110 and the insulating layer 100. A separate printing mask having holes for exposing the lower surface of the metal pad 110 may be attached to the lower surface of the insulating layer 100 to improve the printing accuracy of the conductive member P1.

The conductive member P3 may also be formed on the lower surface of the circuit 111, and the conductive member P3 may be printed (filled) in the space 111' formed by the lower surface of the circuit 111 and the insulating layer 100. When a hole for exposing the lower surface of the circuit 111 is provided in the printing mask, the conductive member P3 may be formed on the lower surface of the circuit 111 . However, if the printed mask covers the lower surface of the circuit 111, the conductive member may not be formed on the lower surface of the circuit 111.

8(a) and 8(b), when the mask M stacked on the upper surface of the insulating layer 100 and the printing mask stacked on the lower surface of the insulating layer 100 are both removed, FIG. 8( The unit substrate in a) is completed.

Figure 8(b) shows the lower surface shown in Figure 8(a). The metal pad 110 has a wider width than the circuit 111 , and the conductive member P1 is formed on the entire lower surface of the metal pad 110 . The conductive member P3 may be formed on at least a portion of the lower surface of the circuit 111 if necessary.

Referring to FIG. 9 , a plurality of unit substrates 10 , 20 , and 30 are pressed at high temperatures and stacked in a parallel configuration to provide a multilayer printed circuit board. Here, the upper portion of the first metal bump 130 is inserted into the conductive member P2 on the lower surface of the second metal pad 210 located above the first metal bump 130 .

Only the first metal bump 130 is inserted into the conductive member P2, and Under the condition that the fluidity of the member P2 is relatively small, the conductive member P2 does not flow outward. Therefore, the printed circuit board according to the first embodiment can be manufactured.

Under the condition that the flowability of the conductive member P2 is stable and there is a gap between the first metal bump 130 and the first insulating layer 100 , the conductive member P2 can flow between the first metal bump 130 and the first insulating layer 100 gap, and may cover a predetermined area or more areas of the side surface of the first metal bump 130 . Therefore, the printed circuit board according to the second embodiment can be manufactured.

Here, depending on the lamination conditions, a region where the conductive member P2 is not formed may exist in the lower surface of the second metal pad 210 . That is, the conductive member P2 may not be formed in locations other than the area where the first metal bump 130 and the second metal pad 210 are in contact.

In addition, the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 may contact each other. In addition, the conductive member P2 and the lower surface of the second metal pad 210 may only make contact around the first metal bump 130 .

On the other hand, under the condition that the fluidity of the conductive member P2 is stable and there is a gap between the second metal pad 210 and the second insulating layer 200 , the conductive member P2 can flow to the second metal pad 210 and the second insulation layer. The gap between the layers 200 covers not only the side surface of the first metal bump 130 but also the side surface of the second metal pad 210 . Therefore, the printed circuit board according to the third embodiment of the present invention can be manufactured.

Furthermore, in this case, the conductive member P2 may cover a predetermined area or more areas of the side surface of the first metal bump 130 .

10 to 11 are cross-sectional views illustrating various processes used in a method of manufacturing a printed circuit board according to another embodiment of the present invention.

The manufacturing method described in FIGS. 10 and 11 is substantially the same as that described with reference to FIGS. 6 to 9 , except that the metal bumps 130 are formed as a single layer. In this case, the metal bump 130 is formed to protrude above the upper surface of the insulating layer 100 . By this method, the printed circuit board according to the fourth embodiment can be manufactured.

12 to 14 are cross-sectional views illustrating various processes used in a method of manufacturing a printed circuit board according to yet another embodiment of the present invention.

FIG. 12 can be understood as a process subsequent to the process shown in FIG. 6 .

Referring to FIG. 12 , a metal bump 130 is formed in the opening portion 120 . The metal bump 130 is formed to protrude above the upper surface of the insulating layer 100 . When the metal bumps 130 are formed into a two-layer structure, the high melting point bumps 131 are formed first, and the relatively thin low melting point bumps 132 are formed on the high melting point bumps 131 . The high melting point bumps 131 and the low melting point bumps 132 can be formed by electrolytic plating. In this case, the electrons move through the metal foil of the carrier.

The mask M may be stacked on the insulating layer 100, and the mask M may protect the metal bumps 130 during an etching process to be described later.

After the mask M is formed on the insulating layer 100, the carrier is removed. Only a portion of the metal foil of the carrier (especially the seed metal foil C2 ) remains, and the seed metal foil C2 can be removed by a separate etching process. Here, when the metal pad 110 and the seed metal foil C2 are formed of the same metal, the lower surface of the metal pad 110 and the seed metal foil C2 are etched together. As a result, the lower surface of the metal pad 110 is recessed beyond the lower surface of the insulating layer 100 .

Similar to the lower surface of the metal pad 110, connect the lower surface of the circuit 111 with The seed metal foil C2 is etched together. In this way, the lower surface of the circuit 111 can be recessed beyond the lower surface of the insulating layer 100 .

The lower surface of the metal pad 110 is subjected to secondary etching to form the recess 300 . The recess 300 may be smaller in area than the metal pad 110 , and the recess 300 may be located in the center of the metal pad 110 . Secondary etching for forming the recess 300 may be performed after stacking an etching mask on the lower surface of the insulating layer 100 . The etching mask covers the lower surface of the circuit 111 so that the recess 300 may not be formed in the lower surface of the circuit 111 .

The depth of the recess 300 may be less than or equal to the thickness of the metal pad 110 and may be set to a predetermined depth considering conductive characteristics.

Specifically, the conductive member P1 is formed on the lower surface of the metal pad 110 , and the conductive member P1 is printed (filled) in the depression 300 . A separate printing mask with holes for exposing the recesses 300 may be attached to the lower surface of the insulating layer 100 to improve the printing accuracy of the conductive member P1.

Referring to FIGS. 13(a) and 13(b) , when the mask M stacked on the upper surface of the insulating layer 100 and the printing mask stacked on the lower surface of the insulating layer 100 are both removed, the unit substrate 10 The production will be completed by 20 and 30.

Figure 13(b) shows the lower surface shown in Figure 13(a). The metal pad 110 has a width wider than the width of the circuit 111 , and the area of the conductive member P1 formed in the recess 300 is smaller than the area of the metal pad 110 . If necessary, the recess 300 may not be formed on the lower surface of the circuit 111 , and the conductive member P1 may not be formed on the lower surface of the circuit 111 .

Referring to FIG. 14 , a plurality of unit substrates 10 , 20 , and 30 are pressed at high temperatures and stacked in a parallel configuration to provide a multilayer printed circuit board. Here, the upper portion of the first metal bump 130 is inserted into the conductive member P2 in the recess 300 on the lower surface of the second metal pad 210 located above the first metal bump 130 . In this way, the printed circuit board according to the fifth embodiment can be manufactured.

Under the condition that the fluidity of the conductive member P2 is relatively small, only the first metal bump 130 is inserted into the conductive member P2, and the conductive member P2 may not flow outward. The conductive member can flow to the gap between the first metal bump 130 and the first insulating layer 100 , and the flowability of the conductive member P2 is stable and there is a gap between the first metal bump 130 and the first insulating layer 100 Conditionally, the conductive member P2 may cover a predetermined area or more areas of the side surface of the first metal bump 130 . There may be a region on the lower surface of the second metal pad 210 where the conductive member P2 is not formed. That is, the conductive member P2 may not be formed in locations other than the area where the first metal pad 130 and the second metal pad 210 are in contact.

The upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 may contact each other. In addition, the conductive member P2 and the lower surface of the second metal pad 210 may only make contact around the first metal bump 130 .

Under the condition that the fluidity of the conductive member P2 is stable and there is a gap between the second metal pad 210 and the second insulating layer 200 , the conductive member P2 can flow to the gap between the second metal pad 210 and the second insulating layer 200 . gap, and the conductive member P2 may cover not only the side surface of the first metal bump 130 but also the side surface of the second metal pad 210 . Furthermore, in this case, the conductive member P2 may cover the first metal protrusion A predetermined area or more areas of the side surface of the block 130.

Although this invention includes specific examples, it will be apparent to those of ordinary skill in the art that various forms may be made in these examples without departing from the spirit and scope of the claimed scope and its equivalents. and changes in details. The examples set forth herein should be considered illustrative only and not limiting. Descriptions of features or aspects in each instance should be deemed to apply to similar features or aspects in other instances. The techniques may be performed in a different order and/or if components in the systems, architectures, devices or circuits are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Achieve appropriate results. Therefore, the scope of the present invention is defined not by the detailed description, but by the patent application scope and its equivalent range, and all changes within the scope of the patent application scope and its equivalent range shall be deemed to be included in the present invention. middle.

100, 200‧‧‧insulation layer

110, 210‧‧‧Metal pads

111, 211‧‧‧circuit

120, 220‧‧‧Opening part

130, 230‧‧‧metal bumps

131, 231‧‧‧High melting point bumps

132, 232‧‧‧Low melting point bumps

P1, P2, P3, P4‧‧‧Conductive components

Claims (22)

A printed circuit board, including: an insulating layer with a metal pad embedded in the lower surface of the insulating layer; an opening portion passing through the insulating layer and formed on the upper surface of the metal pad; metal bumps , formed in the opening portion, and the metal bump has an upper surface protruding above the upper surface of the insulating layer; and a conductive member formed substantially on the entire lower surface of the metal pad, wherein The melting point of the conductive member is lower than the melting point of the metal bump, and the lower surface of the metal pad is recessed beyond the lower surface of the insulating layer. The printed circuit board as claimed in claim 1, wherein the metal bumps include: high melting point bumps, made of metal with a relatively high melting point; and low melting point bumps, formed on the high melting point The bump is on and made of a metal having a relatively low melting point, wherein the melting point of the conductive member is lower than the melting point of the high melting point bump. The printed circuit board as claimed in claim 2, wherein the upper surface of the high melting point bump is located below the upper surface of the insulating layer, and the upper surface of the low melting point bump is located on the on the upper surface of the insulating layer. The printed circuit board described in item 1 of the patent application further includes: a circuit embedded in the lower surface of the insulating layer, wherein a lower surface of the circuit is recessed beyond the lower surface of the insulating layer. The printed circuit board as claimed in claim 4, wherein the conductive member is further formed on the lower surface of the circuit. A printed circuit board, including: an insulating layer with a metal pad embedded in the lower surface of the insulating layer; an opening portion passing through the insulating layer and formed on the upper surface of the metal pad; metal bumps , formed in the opening portion, and the metal bump has an upper surface protruding above the upper surface of the insulating layer; and a conductive member formed on the lower surface of the metal pad, wherein the metal A depression is formed on the lower surface of the pad, and the conductive member is formed in the depression, and the cross-sectional area of the depression is smaller than the cross-sectional area of the metal pad. The printed circuit board as described in item 1 or 6 of the patent application, wherein the insulating layer is made of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyphenylene ether (PPE), cyclic olefin polymer ( Made of at least one of COP) and polyfluoroalkoxy (PFA). A printed circuit board, including: a first insulating layer with a first metal pad embedded in the lower surface of the first insulating layer; a first opening portion passing through the first insulating layer and formed on the third On the upper surface of a metal pad; A first metal bump is formed in the first opening part; a second insulating layer is stacked on the first insulating layer and formed on the first metal bump; a second metal pad is embedded in the lower surface of the second insulating layer and formed on the first metal bump; a first conductive member formed on the lower surface of the second metal pad and in contact with the first metal bump a side surface of the circuit; a circuit embedded in the lower surface of the second insulating layer; and a second conductive member formed substantially on the entire lower surface of the circuit, wherein substantially the entire upper surface of the circuit is covered by the second insulating layer. The printed circuit board as claimed in claim 8, wherein the upper surface of the first metal bump protrudes beyond the upper surface of the first insulating layer, and the lower surface of the second metal pad The recess exceeds the lower surface of the second insulating layer. The printed circuit board as claimed in claim 8, wherein the first conductive member is provided between the upper surface of the first metal bump and the lower surface of the second metal pad. The printed circuit board as claimed in claim 10, wherein the first conductive member is formed on the entire lower surface of the second metal pad. The printed circuit board as claimed in claim 8, wherein the upper surface of the first metal bump and the lower surface of the second metal pad are in contact with each other. The printed circuit board according to claim 12, wherein the first conductive member is formed on the lower surface of the second metal pad that does not contact the first metal bump. The printed circuit board as claimed in claim 8, wherein the first conductive member surrounds a part or the entirety of the side surface of the first metal bump. The printed circuit board of claim 8, wherein the first conductive member extends to the side surface of the second metal pad. The printed circuit board as claimed in claim 8, wherein the first metal bumps include: high melting point bumps made of metal with a relatively high melting point; and low melting point bumps formed on the High melting point bumps are on and made of metals with relatively low melting points. The printed circuit board of claim 8, wherein a depression is formed on the lower surface of the second metal pad, and the first conductive member is filled in the depression. The printed circuit board according to claim 17, wherein the first metal bump is inserted into the recess. The printed circuit board as claimed in claim 17, wherein the cross-sectional area of the recess is smaller than the cross-sectional area of the second metal pad. The printed circuit board as described in item 8 of the patent application further includes: a second opening portion passing through the second insulating layer and formed on the second metal on the upper surface of the pad; and a second metal bump formed in the second opening portion. The printed circuit board as claimed in claim 8, wherein the lower surface of the circuit is recessed beyond the lower surface of the second insulating layer. The printed circuit board as described in item 8 of the patent application, wherein the first insulating layer and the second insulating layer are made of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyphenylene ether (PPE) ), cycloolefin polymer (COP) and polyfluoroalkoxy (PFA).

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