TW201918139A - 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

A printed circuit board

The following description is related to a printed circuit board.

The manner in which printed circuit boards are manufactured is parallel build up lamination and sequential lamination. The parallel configuration stack includes high temperature presses, while the progressive stack includes low temperature presses. When a parallel composition lamination method is employed, a paste can be used as the unit interlayer connection structure. In this case, the adhesion and connectivity between the internal wiring and the paste may be deteriorated.

An example of a printed circuit board is described in Japanese Laid-Open Patent Publication No. 2003-179356.

It is an object of the present invention to provide a printed circuit board having excellent interlayer bonding.

According to an aspect of the present invention, a printed circuit board includes: an insulating layer having a metal pad embedded in a lower surface thereof; an opening portion passing through the insulating layer and formed on an upper surface of the metal pad; a metal bump formed in the opening portion and having an upper surface protruding above the upper surface of the insulating layer; and a conductive member formed on a lower surface of the metal pad, wherein the melting point of the conductive member is lower than a melting point of the metal bump Wherein 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 includes: a first insulating layer having a first metal pad embedded in a lower surface thereof; a first opening portion passing through the first insulating layer and formed on a first metal bump formed on the upper surface of the first metal pad; a second insulating layer laminated on the first insulating layer and formed on the first metal bump; and a conductive member, Formed on a lower surface of the second metal pad and contacting a side surface of the first metal bump.

The following detailed description is provided to assist the reader in a comprehensive understanding of the methods, devices and/or systems described herein. Various modifications, adaptations, and equivalents of the methods, devices, and/or systems described herein will be apparent to those skilled in the art. The order of operations described herein is merely an example, and is not limited to the order of operations referred to herein, but will be apparent to those of ordinary skill in the art, except where the operations must occur in a particular order. Other than that, it can be changed. In addition, descriptions of well-known functions and constructions of those skilled in the art can be omitted for clarity and clarity.

Features described herein can be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided to be thorough and complete, and the full scope of the present invention will be conveyed to those of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning meaning meaning Any term defined in a commonly used dictionary should be interpreted as having the same meaning as in the context of the related art, and should not be construed as having an idealized or overly formal meaning unless explicitly defined otherwise.

Regardless of the figure number, the same or corresponding components will be given the same reference numerals, and the same or corresponding components will not be described again. Throughout the description of the present invention, the detailed description will be omitted when it is stated that the specific related conventional techniques are not related to the viewpoint of the present invention. Terms such as "first" and "second" may be used in the description of various components, but the above components should not be limited to the above terms. The above terms are only used to distinguish between components. In the figures, some components may be exaggerated, omitted or briefly shown, and the dimensions of the components do not necessarily reflect the actual dimensions of the components.

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

Figure 1 shows a printed circuit board in accordance with a first embodiment of the present invention.

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

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

The insulating layer 100 may be made of a material having a low dielectric constant (Dk) and a dielectric loss (Df). Specifically, the insulating layer 100 may be a liquid crystal polymer (LCP), a polytetrafluoroethylene (PTFE), a polyphenylene ether (PPE), or a cyclo olefin polymer (COP). And at least one of perfluoroalkoxy (PFA) is formed. This material is suitable for reducing signal loss 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 an epoxy resin, a polyimide or the like. Examples of the epoxy resin include naphthalene epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and novolac epoxy. Novolac epoxy resin, cresol novolak epoxy resin, rubber modified epoxy resin, cycloaliphatic epoxy resin, lanthanum epoxy A silicon-based epoxy resin, a nitrogen-based epoxy resin, or a phosphorus-based epoxy resin. However, it is not limited to this.

The insulating layer 100 may be a prepreg (PPG) in which a fiber reinforcement material such as glass cloth is contained in a resin. The insulating layer 100 may be a constituent film in which an inorganic filler such as silica is filled in the resin. As the constituent film, an ajinomoto build-up film (ABF) or the like can be used.

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

A circuit 111 and a metal pad 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 that is patterned to transmit electrical signals. Metal pad 110 is a conductor that is connected to the end of circuit 111. The circuit 111 and the metal pad 110 are formed of a metal such as copper (Cu), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), platinum (Pt) or alloy 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 as compared with 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 as compared with 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 can 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 to pass 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 such 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.

The 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. The high melting point bump 131 is a bump made of a metal whose melting point is relatively higher than that of the low melting point bump 132, and the low melting point bump 132 is a bump made of a metal whose melting point is relatively lower than that of the high melting point bump 131. For example, respectively, 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.

The low melting point bumps 132 may be located above the high melting point bumps 131, and the low melting point bumps 132 may have a thickness less than the thickness of the high melting point bumps 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 can 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 a metal such as copper (Cu), tin (Sn), and silver (Ag). Specifically, the conductive member P1 may be a paste containing a 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 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.

The conductive member P1 may be formed more on the lower surface of the circuit 111, and the lower surface of the circuit 111 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 can be formed by the 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 board. The multilayer printed circuit board includes a plurality of insulating layers 100 and 200, circuits 111 and 211, metal pads 110 and 210, opening portions 120, 220, metal bumps 130, 230, conductive members P1, P2, and the like. This will be elaborated on.

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

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

The first circuit 111 and the first metal pad 110 are embedded in the lower surface of the first insulating layer 100. 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 as compared with 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 insulating layer 200 provide a predetermined space.

The lower surface of the first metal pad 110 and the lower surface of the second metal pad 210 may be recessed beyond the lower surface of the first insulating layer 100 as necessary. 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 as compared with the lower surface of the first insulating layer 100. A step height is formed between the lower surface of the first circuit 111 and the lower surface of the first insulating layer 100, and the lower surface of the first circuit 111 and the first insulating layer 100 provide a predetermined space.

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 portion 120 and the second opening portion 220 are disposed to overlap each other. The fact that the first opening 120 and the second opening 220 overlap each other means that the first opening 120 and the second opening 220 overlap each other when the virtual projection is performed on the same plane. Preferably, the first opening 120 and the second opening 220 may be arranged in a row such that the center of the first opening 120 and the center of the second opening 220 coincide with each other.

The first metal bump 130 is formed in the first opening portion 120, and the second metal bump 230 is formed in the second opening portion 220. The first metal bumps 130 and the second metal bumps 230 are the same as the metal bumps described above. 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 a lower surface of the second metal pad 210 to perform interlayer bonding. This is no different from the above-described conductive member P1.

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 a metal such as copper (Cu), tin (Sn), and silver (Ag), and specifically, the conductive member P2 may be a paste containing a metal. However, the materials are not limited to the materials, and any material having electrical 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 a lower surface of the second metal pad 210, and a lower surface of the second metal pad 210 may be recessed beyond a lower surface of the second insulating layer 200. The first metal bump 130 protrudes beyond the upper surface of the first insulating 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 such 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.

A bonding structure composed of a metal bump and a conductive member may be repeatedly formed in the plurality of insulating layers. In other words, although the first insulating layer 100 and the second insulating layer 200 are explained in the above description, the printed circuit board may include three or more insulating layers. This also applies to at least two insulating layers adjacent to each other.

The conductive member P1 may be formed on a lower surface of the first metal pad 110, and a lower surface of the first metal pad 110 is recessed beyond a 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 under the first insulating layer 100.

Conductive members P3 and P4 may also be formed on the lower surface of the first circuit 111 and the lower surface of the second circuit 211, as needed. The conductive members P3 and P4 may be formed on the entire portion or a portion of the lower surface of the circuits 111 and 211.

Figure 2 shows a printed circuit board in accordance with a second embodiment of the present invention.

Referring to FIG. 2, a printed circuit board according to a second embodiment of the present invention includes a first insulating layer 100 having a first metal pad 110 formed thereon, and a second insulating layer 100 having a second metal pad 210 formed thereon, formed on a first opening portion 120 in the first insulating layer 100, a second opening portion 220 formed in the second insulating layer 200, a first metal bump 130 formed in the first opening portion 120, and a second opening portion formed in the second opening portion The second metal bump 230 in 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 of the side surface of the first metal bump 130. Here, the conductive member P2 surrounds a part or the entire portion of the side surface of the first metal bump 130. The "predetermined region" may be a region in which the first metal bump 130 is located in a 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 insulating layer 100 and the second insulating 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 laminated, the conductive member P2 may flow into the gap. And thus, the conductive member P2 may cover a predetermined area or more of the entire side surface of the first metal bump 130. Preferably, the conductive member P2 may cover the entirety 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 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 second conductive pad P2 is not formed. The conductive member P2 may not be formed in a region other than a central region in which the first metal bump 130 contacts the lower surface of the second metal pad 210. However, in the second embodiment, the case where the conductive member P2 is formed on the entire lower surface of the second metal pad 210 as shown in FIG. 4 is not excluded.

The conductive member P2 may be located between the upper surface of the first metal bump 130 and the upper surface of the second metal pad 210 by changing the lamination conditions of the first insulating layer 100 and the second insulating layer 200 as necessary. 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 side of the second metal pad 210 is relatively high, the owner in the conductive member P2 flows into the gap, and the conductive member P2 may not be located first. The upper surface of the metal bump 130 is between 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 in the lower surface of the second metal pad 210 except the region in contact with the first metal bump 130. Part. 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 in accordance with a third embodiment of the present invention.

Referring to FIG. 3, a printed circuit board according to a third embodiment of the present invention includes a first insulating layer 100 having a first metal pad 110 formed thereon, and a second insulating layer 200 having a second metal pad 210 formed thereon, formed on a first opening portion 120 in the first insulating layer 100, a second opening portion 220 formed in the second insulating layer 200, a first metal bump 130 formed in the first opening portion 120, and a second opening portion formed in the second opening portion The second metal bump 230 in 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 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 flow of the conductive member P2 into the gap.

The conductive member P2 may cover a predetermined area or more of the side surface of the first metal bump 130 and also cover a 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 a region 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.

The conductive member P2 may be located between the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 by changing the lamination conditions of the first insulating layer 100 and the second insulating layer 200 as necessary. 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 side of the second metal pad 210 is relatively high, the owner in the conductive member P2 flows into the gap, and the conductive member P2 may not be located first. The upper surface of the metal bump 130 is between the lower surface of the second metal pad 210.

Figure 4 shows a printed circuit board in accordance with a fourth embodiment of the present invention.

Referring to FIG. 4, a printed circuit board according to a fourth embodiment of the present invention includes a first insulating layer 100 on which a first metal pad 110 is formed, and a second insulating layer 200 on which a second metal pad 210 is formed, formed on a first opening portion 120 in the first insulating layer 100, a second opening portion 220 formed in the second insulating layer 200, a first metal bump 130 formed in the first opening portion 120, and a second opening portion formed in the second opening portion The second metal bump 230 in 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 bumps 130 may be formed as a single layer. In this case, the metal bumps 130 may be made of a metal such as copper. That is, the first metal bumps 130 and the second metal bumps 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 in accordance with a fifth embodiment of the present invention.

Referring to FIG. 5, a printed circuit board according to a fifth embodiment of the present invention includes an insulating layer 100 on which a metal pad 110 is formed, 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 a lower surface of the metal pad 110. Further, a recess is formed on the lower surface of the metal pad 110, and the conductive member P1 is filled in the recess.

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

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

When there is a gap between the first metal bump 130 and the first insulating layer 100, the conductive member P2 flows into the gap to cover a predetermined area or more 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, and the like, the conductive member P2 may move beyond the recess 300 to reach the lower surface (not shown) of the second metal pad 210. Further, 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 a side surface (not shown) of the second metal pad 210.

Hereinafter, a method of manufacturing a printed circuit board will be explained.

6 to 9 are cross-sectional views showing respective 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 is provided in which metal foils are laminated on both surfaces of an insulating material C0. The insulating material C0 may be a prepreg or the like. The metal foil may be formed on each side of the insulating material C0 in a two-layer structure, and the two-layer structure may be a copper layer. The metal foil on both surfaces contacting the insulating material C0 may be a carrier metal foil C1 having a thickness of 18 micrometers (μm), and the metal foil laminated on the carrier metal foil C1 may be a seed metal foil having 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 a metal foil, and the resist film R is patterned by 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 the metal foil of the carrier.

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

The 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 by an exposure and development process. On the other hand, when the insulating layer 100 is non-photosensitive, the opening portion 120 can be formed by a laser process.

Figure 7 shows the process associated with Figure 6.

Referring to FIG. 7, after the desmear is performed to remove the residue (slag) in the opening portion 120, the metal bumps 130 are 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 bump 130 is formed in a two-layer structure, the high melting point bump 131 is first formed, and the low melting point bump 132 having a relatively small thickness is formed on the high melting point bump 131. The high melting point bumps 131 and the low melting point bumps 132 can be formed by electrolytic plating. In this case, electrons move through the metal foil of the carrier.

The mask M is stacked on the insulating layer 100, and the mask M can protect the metal bumps 130 in an etching process or the like 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 (particularly 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 is etched together with the seed metal foil C2. 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 forms a space 110' with the insulating layer 100.

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 constitute a space 111'.

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 space 110' formed by the lower surface of the metal pad 110 and the insulating layer 100. A separate printed 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 printed 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.

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

Fig. 8(b) shows the lower surface shown in Fig. 8(a). The metal pad 110 has a width wider than that of the circuit 111, and a 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 as needed.

Referring to Fig. 9, a plurality of unit substrates 10, 20, and 30 are pressed at a high temperature to perform parallel configuration lamination 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 conductive 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.

The conductive member P2 may flow between the first metal bump 130 and the first insulating layer 100 under the condition that the fluidity 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 gap may cover a predetermined area or more 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 condition, 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 at a portion other than the region where the first metal pad 130 and the second metal pad 210 are in contact with each other.

In addition, the upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 may be in contact with each other. Further, the conductive member P2 and the lower surface of the second metal pad 210 may be in contact only 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 may flow to the second metal pad 210 and the second insulation. 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, a printed circuit board according to the third embodiment of the present invention can be manufactured.

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

10 to 11 are cross-sectional views showing respective 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 the method 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 bumps 130 are 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 showing respective processes used in a method of manufacturing a printed circuit board according to still another embodiment of the present invention.

Figure 12 can be understood as a process that is connected after the process shown in Figure 6.

Referring to FIG. 12, metal bumps 130 are 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 bump 130 is formed in a two-layer structure, the high melting point bump 131 is first formed, and the low melting point bump 132 having a relatively small thickness is formed on the high melting point bump 131. The high melting point bumps 131 and the low melting point bumps 132 can be formed by electrolytic plating. In this case, 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 in an etching process or the like 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 (particularly 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 is etched together with the seed metal foil C2. 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, 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 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. The secondary etching for forming the recess 300 may be performed after laminating the etching mask on the lower surface of the insulating layer 100. The etch mask covers the lower surface of the circuit 111 such 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 in consideration of electrical conductivity 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 recess 300. A separate printed mask having holes for exposing the recess 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 printed mask stacked on the lower surface of the insulating layer 100 are both removed, the unit substrate 10 is removed. And 20, 30 production is completed.

Fig. 13 (b) shows the lower surface shown in Fig. 13 (a). The metal pad 110 has a width wider than that 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. The recess 300 may not be formed on the lower surface of the circuit 111 as necessary, 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 a high temperature to perform parallel configuration lamination 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 may flow to a gap between the first metal bump 130 and the first insulating layer 100, and the fluidity of the conductive member P2 is stable and there is a gap between the first metal bump 130 and the first insulating layer 100. In the condition, the conductive member P2 may cover a predetermined area or more of the side surface of the first metal bump 130. A region where the conductive member P2 is not formed may exist on the lower surface of the second metal pad 210. That is, the conductive member P2 may not be formed at a portion other than the region where the first metal pad 130 and the second metal pad 210 are in contact with each other.

The upper surface of the first metal bump 130 and the lower surface of the second metal pad 210 may be in contact with each other. Further, the conductive member P2 and the lower surface of the second metal pad 210 may be in contact only around the first metal bump 130.

The conductive member P2 may flow between the second metal pad 210 and the second insulating layer 200 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 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. Further, in this case, the conductive member P2 may cover a predetermined area or more of the side surface of the first metal bump 130.

Although the present invention includes specific examples, it will be apparent to those skilled in the art that various forms can be made in the examples without departing from the spirit and scope of the scope of the claims. And changes in the details. The examples described herein are to be considered as illustrative only and not as limiting. Descriptions of features or aspects in each instance should be considered as suitable features or aspects in other examples. If the techniques are performed in a different order and/or if components in the system, architecture, apparatus, or circuitry are combined and/or replaced or supplemented with other components or equivalent components thereof, Achieve a suitable result. Therefore, the scope of the invention is not to be limited by the details of the invention, but the scope of the claims and the equivalents thereof in.

10, 20, 30‧‧‧ unit substrate

100, 200‧‧‧ insulation

110, 210‧‧‧ metal pads

110’, 111’‧‧‧ space

111, 211‧‧‧ circuits

120, 220‧‧‧ openings

130, 230‧‧‧ metal bumps

131, 231‧‧‧ high melting point bumps

132, 232‧‧‧low melting point bumps

300‧‧‧ dent

P1, P2, P3, P4‧‧‧ conductive members

C0‧‧‧Insulation material

C1‧‧‧ carrier metal foil

C2‧‧‧ seed metal foil

R‧‧‧resist film

M‧‧‧ mask

Figure 1 shows a printed circuit board in accordance with a first embodiment of the present invention. Figure 2 shows a printed circuit board in accordance with a second embodiment of the present invention. Figure 3 shows a printed circuit board in accordance with a third embodiment of the present invention. Figure 4 shows a printed circuit board in accordance with a fourth embodiment of the present invention. Figure 5 shows a printed circuit board in accordance with a fifth embodiment of the present invention. 6 to 9 are cross-sectional views showing respective 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 showing respective 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 showing respective processes used in a method of manufacturing a printed circuit board according to still another embodiment of the present invention. Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The figures may not be drawn to scale, and the relative size, proportions, and depictions of the elements in the drawings may be exaggerated for clarity, illustration, and convenience.

Claims (23)

A printed circuit board comprising: an insulating layer, a metal pad embedded in a lower surface of the insulating layer; an opening portion passing through the insulating layer and formed on an upper surface of the metal pad; metal bump Formed in the opening portion, and the metal bump has an upper surface protruding above an upper surface of the insulating layer; and a conductive member formed on a lower surface of the metal pad, wherein the conductive The melting point of the member is lower than the melting point of the metal bump, and wherein the lower surface of the metal pad is recessed beyond the lower surface of the insulating layer. The printed circuit board of claim 1, wherein the metal bump comprises: a high melting point bump made of a metal having a relatively high melting point; and a low melting point bump formed at the high melting point The bump is made of a metal having a relatively low melting point, wherein the conductive member has a melting point lower than a melting point of the high melting point bump. The printed circuit board of claim 2, wherein an upper surface of the high melting point bump is located below an upper surface of the insulating layer, and an upper surface of the low melting point bump is located in the insulating layer On the upper surface. The printed circuit board according to claim 1, wherein a recess is formed on a lower surface of the metal pad, and the conductive member is formed in the recess. The printed circuit board of claim 1, further comprising: a circuit embedded in a lower surface of the insulating layer, wherein a lower surface of the circuit is recessed beyond a lower surface of the insulating layer. The printed circuit board of claim 5, wherein the conductive member is formed on a lower surface of the circuit. The printed circuit board of claim 1, wherein the insulating layer is composed of a liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyphenylene ether (PPE), and a cyclic olefin polymer (COP). And at least one of perfluoroalkoxy (PFA) is produced. A printed circuit board comprising: a first insulating layer, a first metal pad embedded in a lower surface of the first insulating layer; a first opening portion passing through the first insulating layer and formed in the first a first metal bump formed on the upper surface; a second insulating layer laminated on the first insulating layer and formed on the first metal bump; And a conductive member formed on a lower surface of the second metal pad and contacting a side surface of the first metal bump. The printed circuit board of claim 8, wherein an upper surface of the first metal bump protrudes beyond an upper surface of the first insulating layer, and a lower surface of the second metal pad is recessed more than a lower surface of the second insulating layer. The printed circuit board of claim 8, wherein the conductive member is provided between an upper surface of the first metal bump and a lower surface of the second metal pad. The printed circuit board of claim 10, wherein the conductive member is formed on the entire lower surface of the second metal pad. The printed circuit board of claim 8, wherein an upper surface of the first metal bump and a lower surface of the second metal pad are in contact with each other. The printed circuit board of claim 12, wherein the conductive member is formed on a lower surface of the second metal pad that does not contact the first metal bump. The printed circuit board of claim 8, wherein the conductive member surrounds a portion or the entirety of a side surface of the first metal bump. The printed circuit board of claim 8, wherein the conductive member extends to a side surface of the second metal pad. The printed circuit board of claim 8, wherein the metal bump comprises: a high melting point bump made of a metal having a relatively high melting point; and a low melting point bump formed at the high melting point On the bump and made of metal having a relatively low melting point. The printed circuit board of claim 8, wherein a recess is formed on a lower surface of the second metal pad, and the conductive member is filled in the recess. The printed circuit board of claim 17, wherein the first metal bump is inserted into the recess. The printed circuit board of claim 17, wherein the recess has a cross-sectional area smaller than a cross-sectional area of the second metal pad. The printed circuit board of claim 8, further comprising: a second opening portion passing through the second insulating layer and formed on an upper surface of the second metal pad; and a second metal protrusion a block formed in the second opening portion. The printed circuit board of claim 8, further comprising: a circuit embedded in a lower surface of the second insulating layer, wherein a lower surface of the circuit is recessed beyond the second insulating layer surface. The printed circuit board of claim 21, wherein the conductive member is formed on a lower surface of the circuit. The printed circuit board of claim 8, wherein the first insulating layer and the second insulating layer are made of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), and polyphenylene ether (PPE). And at least one of a cycloolefin polymer (COP) and a perfluoroalkoxy group (PFA).