TW202006899A - Printed circuit board - Google Patents

Abstract

A printed circuit board in accordance with an aspect of the present disclosure includes: first insulating layer; second insulating layer made of a flexible material and laminated on the first insulating layer; first circuit formed on a lower surface of the first insulating layer and embedded in the first insulating layer; second circuit formed on a lower surface of the second insulating layer and laminated in the first insulating layer; and third circuit formed on an upper surface of the second insulating layer, wherein a pitch of the second circuit is smaller than a pitch of the first circuit.

Description

A printed circuit board

The invention relates to a printed circuit board.

When the printed circuit boards used for packaging are required to be thin and small, precise pitch wiring is also required to be formed on these printed circuit boards. The thickness of the printed circuit board can be minimized by coreless method or by using thin materials. In addition, the width and space of the wiring can be controlled to have a precise pitch through a modified semi-additive process (MSAP) or semi-additive process (SAP).

Related technology is described in Korean Patent No. 10-1593280 (February 11, 2016).

The present invention aims to provide a printed circuit board including a precision pitch circuit.

An aspect of the present invention provides a printed circuit board including: a first insulating layer; a second insulating layer made of a flexible material and laminated on the first insulating layer; a first circuit formed On the lower surface of the first insulating layer and embedded in the first insulating layer; a second circuit formed on the lower surface of the second insulating layer and stacked in the first insulating layer; and A third circuit is formed on the upper surface of the second insulating layer, wherein the pitch of the second circuit is smaller than the pitch of the first circuit.

The following detailed instructions are provided to help the reader fully understand the methods, devices, and/or systems described herein. However, those skilled in the art will understand various changes, retouching, and equivalent forms of the methods, devices, and/or systems described herein. The order of operations described in this article is only an example, and is not limited to the examples described in this document, but as those skilled in the art will understand that changes can be made, except for operations that must occur in a specific order. In addition, for clarity and conciseness, descriptions of functions and structures well known to those skilled in the art may be omitted.

The features described herein can be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided so that the invention 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 used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art who are familiar with the present invention. Any term defined in an ordinary dictionary should be understood to have the same meaning in the context of the related art, and unless clearly defined otherwise, the term should not be interpreted as having an idealized or overly formal meaning.

Regardless of the drawing number, the same or corresponding elements will be given the same reference number, and the same or corresponding elements will not be described any more. Throughout the description of the present invention, when a certain related conventional technology is 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 to describe various elements, but the above elements should not be limited to the above terms. The above terms are only used to distinguish one element from another. In the drawings, some elements may be enlarged, omitted, or briefly explained, and the size of the element does not necessarily reflect the actual size of the element.

In the following, certain embodiments of the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a printed circuit board according to an embodiment of the present invention.

Referring to FIG. 1, a printed circuit board according to an embodiment of the present invention includes a first insulating layer 110, a second insulating layer 120, a first circuit 210, a second circuit 220 and a third circuit 230.

The first insulating layer 110 is a layer having insulating properties and mainly made of an insulating material. The first insulating layer 110 may be made of a rigid material with little flexibility. For example, epoxy resin, phenol resin or bismaleimide triazine (BT) resin can be used as the rigid material. The epoxy resin may be (but not limited to) for example: naphthalene epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, cresol novolac epoxy resin, rubber modified Epoxy resin, cycloaliphatic epoxy resin, silicon epoxy resin, nitrogen epoxy resin or phosphorus epoxy resin.

The first insulating layer 110 may be a prepreg (PPG) containing fiber reinforcement such as glass fiber fabric. The first insulating layer 110 may be a laminated film filled with an inorganic filler (such as silicon dioxide). Ajinomoto Build-up Film (ABF) can be used as this laminate film.

The second insulating layer 120 is a layer having insulating properties and mainly made of an insulating material. The second insulating layer 120 is stacked on the first insulating layer 110, in which case the first insulating layer 110 and the second insulating layer 120 are bonded to each other.

The second insulating layer 120 may be made of a flexible material with high flexibility. Polyimide (PI), liquid crystal polymer (LCP), etc. can be used as the flexible material.

The first circuit 210, the second circuit 220, and the third circuit 230 are used to transmit electrical signals, and may be made of copper (Cu), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold ( Au), platinum (Pt), or other metals, or alloys of some of these metals in consideration of their electrical conductivity.

The first circuit 210, the second circuit 220, and the third circuit 230 may each be made of conductive wiring, and the conductive wiring may be provided in plural.

The first circuit 210 is formed on the lower surface of the first insulating layer 110 and embedded in the first insulating layer 110. Since the first circuit 210 is embedded in the first insulating layer 110, the first circuit 210 excluding the lower surface of the first circuit 210 (that is, the surface of the first circuit 210 placed on the lower side in FIG. 1) The outer surfaces are in contact with the first insulating layer 110. At the same time, the lower surface of the first insulating layer 110 may be located further inside the lower surface of the first insulating layer 100.

The second circuit 220 is formed on the lower surface of the second insulating layer 120 and embedded in the first insulating layer 110. The upper surface of the second circuit 220 (that is, the surface of the second circuit 220 placed on the upper side in FIG. 1) is in contact with the lower surface of the second insulating layer 120, and the second circuit 220 except the second circuit 220 The surfaces other than the upper surface are in contact with the first insulating layer 110.

The third circuit 230 is formed on the upper surface of the second insulating layer 120. The third circuit 230 is in contact with the upper surface of the second insulating layer 120 and protrudes from the upper surface of the second insulating layer 120 beyond the second insulating layer 120.

The pitch of the second circuit 220 is smaller than the pitch of the first circuit 210. In addition, the width of the second circuit 220 may be smaller than the width of the first circuit 210, and the space of the second circuit 220 may be smaller than the space of the first circuit 210.

Here, the "pitch" of a circuit may refer to the distance between the centers of the wires constituting the circuit. In addition, the "width" of a circuit may refer to the width of the wires that make up the circuit, and the "space" of the circuit may refer to the separation distance between the wires that make up the circuit (eg, between the opposite inner sides of each wire distance).

In addition, the pitch of the third circuit 230 may be smaller than the pitch of the first circuit 210. The width of the third circuit 230 may be smaller than the width of the first circuit 210, and the space of the third circuit 230 may be smaller than the space of the first circuit 210.

For example, the pitch of the second circuit 220 and the pitch of the third circuit 230 may each be about 20 microns, and the pitch of the first circuit 210 may be greater than this pitch.

In other words, the second circuit 220 and the third circuit 230 may be formed denser than the first circuit 210. In addition, the second circuit 220 and the third circuit 230 may be formed to be more precise than the first circuit 210.

Referring to FIG. 1, a printed circuit board according to an embodiment of the present invention may further include a first via 310 and a second via 320.

The first via 310 is a conductive structure penetrating the first insulating layer 110 to electrically connect the first circuit 210 and the second circuit 220. The second via 320 is a conductive structure penetrating the second insulating layer 120 to electrically connect the second circuit 220 and the third circuit 230.

The melting point of the first via 310 may be lower than the melting point of the first circuit 210. The first via 310 may be made of conductive paste. Here, the conductive paste may be a paste containing metal, or a paste made of a conductive polymer but not containing any metal. The metal contained in the paste may be one or more of silver (Ag), tin (Sn), nickel (Ni), and copper (Cu). In an example, the first circuit 210 may be mainly made of copper, and the first via 310 may be mainly made of tin. This example of conductive paste is filled in the through hole and then metallized to become the first via 310 through a reflow process or a heating/cooling process.

The cross-sectional area of the first via 310 may increase from the lower surface of the first insulating layer 110 to the upper surface of the first insulating layer 110. In this case, the longitudinal section of the first via 310 may have an inverted trapezoidal shape.

The first circuit 210 may include a first pad 410, which may be formed on the lower surface of the first insulating layer 110 to be embedded in the first insulating layer 110, which is similar to the first circuit 210. The first pad 410 may be formed at an end portion of the wire constituting the first circuit 210. The thickness of the first pad 410 may be substantially the same as the thickness of the first circuit 210, and the width of the first pad 410 may be greater than the width of the first circuit 210, and the cross section of the first pad 410 may be nearly circular of.

The first via 310 may be in contact with the first pad 410. Specifically, the lower surface of the first via 310 may be in contact with the upper surface of the first pad 410.

The melting point of the second via 320 may be higher than the melting point of the first via 310. For example, the second via 320 may be mainly made of copper, and the first via 310 may be mainly made of tin. In addition, the second via 320 may be a plated via formed by plating.

The second via 320 may penetrate the second insulating layer 120 from the upper surface to the lower surface of the second insulating layer 120. The cross-sectional area of the second via 320 may (but is not limited to) first decrease from the upper surface of the second insulating layer 120 toward the lower surface and then increase.

The second circuit 220 may include a second pad 420, which may be formed on the lower surface of the second insulating layer 120 to be embedded in the first insulating layer 110, which is similar to the second circuit 220. The second pad 420 may be formed at an end portion of the wire constituting the second circuit 220. The thickness of the second pad 420 may be substantially the same as the thickness of the second circuit 220, and the width of the second pad 420 may be greater than the width of the second circuit 220, and the cross section of the second pad 420 may be nearly circular of.

The first via 310 may be in contact with the second pad 420. Specifically, the upper surface of the first via 310 may be in contact with the lower surface of the second pad 420. In addition, the second via 320 may be in contact with the second pad 420. Specifically, the lower surface of the second via 320 may be in contact with the upper surface of the second pad 420.

The third circuit 230 may include a third pad 430, which may be formed on the upper surface of the second insulating layer 120 to protrude outward, which is similar to the third circuit 230. The third pad 430 may be formed at an end portion of the wire constituting the third circuit 230. The thickness of the third pad 430 may be substantially the same as the thickness of the third circuit 230, and the width of the third pad 430 may be greater than the width of the third circuit 230, and the cross section of the third pad 430 may be nearly circular of.

The second via 320 may be in contact with the third pad 430. Specifically, the upper surface of the second via 320 may be in contact with the lower surface of the third pad 430.

In an example, electrical signals can be transmitted through the following routes: first circuit 210—first pad 410—first path 310—second pad 420—second circuit 220; or first circuit 210—first pad 410 -First path 310-Second pad 420-Second path 320-Third pad 430-Third circuit 230.

At the same time, the first pad 410 and the third pad 430 may be coupled to the connection part 500 respectively. The connection member 500 may be a solder bump or a solder ball. Such a connection member 500 is configured to electrically connect the printed circuit board and the electronic device (or external board) and physically join the printed circuit board and the electronic device. In other words, the printed circuit board and the electronic device (or external board) are joined to each other by the connecting member 500.

In an example, the connection member 500 placed on the upper side of the printed circuit board (that is, the connection member 500 coupled to the third pad 430) may be coupled to the electronic device, and the connection placed on the lower side of the printed circuit board The component 500 (ie, the connection component 500 coupled to the first pad 410) may be coupled to the external board. In this case, the electrical signal can be transmitted through the following route: external board-connecting part 500-first pad 410-first path 310-second pad 420-second path 320-third pad 430-connection Component 500-electronic device.

A solder resist layer 600 may be stacked on the lower surface of the first insulating layer 110, and a solder resist layer 600 may also be stacked on the upper surface of the second insulating layer 120. The solder resist layer 600 may be configured to protect the first circuit 210 and the third circuit 230. At the same time, an opening (or through hole) may be formed in the solder resist layer 600 to partially expose the first pad 410 and the third pad 430, and the connection part 500 may be coupled in the opening.

2 shows a printed circuit board according to an embodiment of the present invention.

2, a printed circuit board according to an embodiment of the present invention includes: an insulating material 100, a first insulating layer 110, a second insulating layer 120, a third insulating layer 130, a fourth insulating layer 140, a first circuit 210, a first The second circuit 220, the third circuit 230, the fourth circuit 240, the fifth circuit 250 and the sixth circuit 260.

The insulating material 100 is a portion that becomes the core of the printed circuit board and supports the printed circuit board. The insulating material 100 may be made of an insulating material such as epoxy resin, and the insulating material 100 may contain a reinforcing material 100a. The reinforcing material 100a may be a fiber reinforcing material such as glass fiber fabric. The insulating material 100 may be a copper clad laminate (CCL) excluding copper foil.

The first insulating layer 110 may be stacked on one surface of the insulating material 100. The first insulating layer 110 may be stacked on the upper surface of the insulating material 100. In this case, the insulating material 100 may be in contact with the lower surface of the first insulating layer 110. In addition, the second insulating layer 120 may be stacked above the first insulating layer 110.

At the same time, a third insulating layer 130 may be stacked on the other surface of the insulating material 100. In this case, the insulating material 100 may be in contact with the upper surface of the third insulating layer 130. In addition, the fourth insulating layer 140 may be stacked under the third insulating layer 130.

The first insulating layer 110 and the third insulating layer 130 are substantially the same as each other, and the second insulating layer 120 and the fourth insulating layer 140 are substantially the same as each other, and the printed circuit board may be symmetrical with respect to the insulating material 100.

However, the present invention is not necessarily limited to the structure described above, and when (for example) the first insulating layer 110 and the second insulating layer 120 are stacked on the insulating material 100 and only the third insulating layer 130 is stacked on the insulating material When below 100, the printed circuit board may be asymmetric with respect to the insulating material 100. In addition, the first insulating layer 110 and the second insulating layer 120 are stacked above the insulating material 100, and the third insulating layer 130 and the fourth insulating layer 140 are stacked under the insulating material, but the first insulating layer 110 and the third insulating layer 130 It may be substantially different from each other (in terms of material or thickness), and the second insulating layer 120 and the fourth insulating layer 140 may be substantially different from each other (in terms of material or thickness).

In the following, the first insulating layer 110, the second insulating layer 120, the third insulating layer 130, and the fourth insulating layer 140 will be further described. However, since the first insulating layer 110 and the second insulating layer 120 have been explained above with reference to FIG. 1, the first insulating layer 110 and the second insulating layer 120 will not be repeated here.

The third insulating layer 130 is a layer having insulating properties and mainly made of an insulating material. The third insulating layer 130 may be made of a rigid material with little flexibility. For example, epoxy resin, phenol resin or BT resin can be used as the rigid material. The epoxy resin may be (but not limited to) for example: naphthalene epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, cresol novolac epoxy resin, rubber modification Epoxy resin, cycloaliphatic epoxy resin, silicon epoxy resin, nitrogen epoxy resin or phosphorus epoxy resin.

The third insulating layer 130 may be a prepreg (PPG) containing fiber reinforcement such as glass fiber fabric. The third insulating layer 130 may be a laminated film filled with an inorganic filler (such as silicon dioxide). Ajinomoto laminated film (ABF) can be used as this laminated film.

The fourth insulating layer 140 is a layer having insulating properties and mainly made of an insulating material. The fourth insulating layer 140 may be made of a flexible material with high flexibility. Polyimide (PI), liquid crystal polymer (LCP), etc. can be used as the flexible material.

The first circuit 210, the second circuit 220, the third circuit 230, the fourth circuit 240, the fifth circuit 250, and the sixth circuit 260 are used to transmit electrical signals, and may be made of copper (Cu), palladium (Pd), aluminum ( Al), nickel (Ni), titanium (Ti), gold (Au), platinum (Pt), or other metals, or alloys of some of these metals in consideration of their electrical conductivity.

The first circuit 210, the second circuit 220, the third circuit 230, the fourth circuit 240, the fifth circuit 250, and the sixth circuit 260 may each be made of conductive wiring, and the conductive wiring may be provided in plural.

The first circuit 210 is formed on the lower surface of the first insulating layer 110 and embedded in the first insulating layer 110. Since the first circuit 210 is embedded in the first insulating layer 110, the lower surface of the first circuit 210 except the first circuit 210 (that is, the surface of the first circuit 210 placed on the lower side in FIG. 2) The outer surfaces are in contact with the first insulating layer 110.

In addition, the first circuit 210 is formed on one surface (ie, upper surface) of the insulating material 100.

The second circuit 220 is formed on the lower surface of the second insulating layer 120 and embedded in the first insulating layer 110. The upper surface of the second circuit 220 (that is, the surface of the second circuit 220 placed on the upper side in FIG. 2) is in contact with the lower surface of the second insulating layer 120, and the second circuit 220 except the second circuit 220 The surfaces other than the upper surface are in contact with the first insulating layer 110.

The third circuit 230 is formed on the upper surface of the second insulating layer 120. The third circuit 230 is in contact with the upper surface of the second insulating layer 120 and protrudes from the upper surface of the second insulating layer 120 beyond the second insulating layer 120.

The pitch of the second circuit 220 is smaller than the pitch of the first circuit 210. In addition, the width of the second circuit 220 may be smaller than the width of the first circuit 210, and the space of the second circuit 220 may be smaller than the space of the first circuit 210.

In addition, the pitch of the third circuit 230 may be smaller than the pitch of the first circuit 210. The width of the third circuit 230 may be smaller than the width of the first circuit 210, and the space of the third circuit 230 may be smaller than the space of the first circuit 210.

For example, the pitch of the second circuit 220 and the pitch of the third circuit 230 may each be about 20 microns, and the pitch of the first circuit 210 may be greater than this pitch.

In other words, the second circuit 220 and the third circuit 230 may be formed denser than the first circuit 210. In addition, the second circuit 220 and the third circuit 230 may be formed to be more precise than the first circuit 210.

The fourth circuit 240 is formed on the other surface (ie, the lower surface) of the insulating material 100 and is embedded in the third insulating layer 130. Since the fourth circuit 240 is embedded in the third insulating layer 130, the top surface of the fourth circuit 240 except the fourth insulating layer 240 (that is, the surface of the fourth circuit 240 placed on the upper side in FIG. 2) The outer surfaces are in contact with the third insulating layer 130.

The fifth circuit 250 is formed on the lower surface of the third insulating layer 130 and embedded in the third insulating layer 130. The surfaces of the fifth circuit 250 other than the lower surface of the fifth circuit 250 (that is, the surface of the fifth circuit 250 placed on the lower side in FIG. 2) are in contact with the third insulating layer 130. The fifth circuit 250 is located on one surface (ie, upper surface) of the fourth insulating layer 140.

The sixth circuit 260 is formed on the other surface (ie, the lower surface) of the fourth insulating layer 140. The sixth circuit 260 is in contact with the lower surface of the fourth insulating layer 140 and protrudes outward from the other surface (ie, the lower surface) of the fourth insulating layer 140.

The pitch of the fifth circuit 250 is smaller than the pitch of the fourth circuit 240. In addition, the width of the fifth circuit 250 may be smaller than the width of the fourth circuit 240, and the space of the fifth circuit 250 may be smaller than the space of the fourth circuit 240.

In addition, the pitch of the sixth circuit 260 may be smaller than the pitch of the fourth circuit 240. The width of the sixth circuit 260 may be smaller than the width of the fourth circuit 240, and the space of the sixth circuit 260 may be smaller than the space of the fourth circuit 240.

For example, the pitch of the fifth circuit 250 and the pitch of the sixth circuit 260 may each be about 20 microns, and the pitch of the fourth circuit 240 may be greater than this pitch.

In other words, the fifth circuit 250 and the sixth circuit 260 may be formed denser than the fourth circuit 240. In addition, the fifth circuit 250 and the sixth circuit 260 may be formed to be more precise than the fourth circuit 240.

The first circuit 210 and the fourth circuit 240 may be symmetrical to each other, the second circuit 220 and the fifth circuit 250 may be symmetrical to each other, and the third circuit 230 and the sixth circuit 260 may be symmetrical to each other.

Referring to FIG. 2, the printed circuit board according to the embodiment of the present invention may further include a through via 100 b, a first via 310, a second via 320, a third via 330 and a fourth via 340.

The through via 100 b penetrates the insulating material 100 to electrically connect the first circuit 210 and the fourth circuit 240. The through via 100b may be a plated via and may be made of the same metal as the first circuit 210. The through via 100b may penetrate the insulating material 100 from one surface of the insulating material 100 to another surface, and the cross-sectional area of the through via 100b may first decrease from one surface of the insulating material 100 toward the other surface and then increase . The upper surface of the through via 100b may be in contact with the first pad 410 of the first circuit 210, and the lower surface of the through via 100b may be in contact with the fourth pad 440 of the fourth circuit 240.

The first via 310 is configured to electrically connect the conductive structure of the first circuit 210 and the second circuit 220 by penetrating the first insulating layer 110. In addition, the second via 320 is configured to electrically connect the conductive structure of the second circuit 220 and the third circuit 230 by penetrating the second insulating layer 120.

The melting point of the first via 310 may be lower than the melting point of the first circuit 210. The first via 310 may be made of conductive paste. Here, the conductive paste may be a paste containing metal, or a paste made of a conductive polymer but not containing any metal. The metal contained in the paste may be one or more of silver (Ag), tin (Sn), nickel (Ni), and copper (Cu). In an example, the first circuit 210 may be mainly made of copper, and the first via 310 may be mainly made of tin. This example of conductive paste is filled in the through hole and then metallized to become the first via 310 through a reflow process or a heating/cooling process.

The cross-sectional area of the first via 310 may increase from the lower surface of the first insulating layer 110 to the upper surface of the first insulating layer 110. In this case, the longitudinal section of the first via 310 may have an inverted trapezoidal shape.

The first circuit 210 may include a first pad 410, which may be formed on the lower surface of the first insulating layer 110 to be embedded in the first insulating layer 110, which is similar to the first circuit 210. The first pad 410 may be formed at an end portion of the wire constituting the first circuit 210. The thickness of the first pad 410 may be substantially the same as the thickness of the first circuit 210, and the width of the first pad 410 may be greater than the width of the first circuit 210, and the cross section of the first pad 410 may be nearly circular of.

The first via 310 may be in contact with the first pad 410. Specifically, the lower surface of the first via 310 may be in contact with the upper surface of the first pad 410. In addition, as described above, the through via 110b may be in contact with the first pad 410.

The melting point of the second via 320 may be higher than the melting point of the first via 310. For example, the second via 320 may be mainly made of copper, and the first via 310 may be mainly made of tin. In addition, the second via 320 may be a plated via formed by plating.

The second via 320 may penetrate the second insulating layer 120 from the upper surface to the lower surface of the second insulating layer 120. The cross-sectional area of the second via 320 may (but is not limited to) first decrease from the upper surface of the second insulating layer 120 toward the lower surface and then increase.

The second circuit 220 may include a second pad 420, which may be formed on the lower surface of the second insulating layer 120 to be embedded in the first insulating layer 110, which is similar to the second circuit 220. The second pad 420 may be formed at an end portion of the wire constituting the second circuit 220. The thickness of the second pad 420 may be substantially the same as the thickness of the second circuit 220, and the width of the second pad 420 may be greater than the width of the second circuit 220, and the cross section of the second pad 420 may be nearly circular of.

The first via 310 may be in contact with the second pad 420. Specifically, the upper surface of the first via 310 may be in contact with the lower surface of the second pad 420. In addition, the second via 320 may be in contact with the second pad 420. Specifically, the lower surface of the second via 320 may be in contact with the upper surface of the second pad 420.

The third circuit 230 may include a third pad 430, which may be formed on the upper surface of the second insulating layer 120 to protrude outward, which is similar to the third circuit 230. The third pad 430 may be formed at an end portion of the wire constituting the third circuit 230. The thickness of the third pad 430 may be substantially the same as the thickness of the third circuit 230, and the width of the third pad 430 may be greater than the width of the third circuit 230, and the cross section of the third pad 430 may be nearly circular of.

The second via 320 may be in contact with the third pad 430. Specifically, the upper surface of the second via 320 may be in contact with the lower surface of the third pad 430.

The third via 330 is configured to electrically connect the conductive structure of the fourth circuit 240 and the fifth circuit 250 by penetrating the third insulating layer 130. In addition, the fourth via 340 is configured to electrically connect the conductive structure of the second circuit 220 and the third circuit 230 by penetrating the second insulating layer 120.

The melting point of the third via 330 may be lower than the melting point of the fourth circuit 240. The third via 330 may be made of conductive paste. Here, the conductive paste may be a paste containing metal, or a paste made of a conductive polymer but not containing any metal. The metal contained in the paste may be one or more of silver (Ag), tin (Sn), nickel (Ni), and copper (Cu). In an example, the fourth circuit 240 may be mainly made of copper, and the third via 330 may be mainly made of tin. This example of the conductive paste is filled in the through hole and then metallized to become the third via 330 through the reflow process or the heating/cooling process.

The cross-sectional area of the third via 330 may increase from the upper surface to the lower surface of the fourth insulating layer 140. In this case, the longitudinal section of the third passage 330 may have a trapezoidal shape.

The fourth circuit 240 may include a fourth pad 440, which may be formed on the lower surface of the insulating material 100 to be embedded in the third insulating layer 130, which is similar to the fourth circuit 240. The fourth pad 440 may be formed at an end portion of the wire constituting the fourth circuit 240. The thickness of the fourth pad 440 may be substantially the same as the thickness of the fourth circuit 240, and the width of the fourth pad 440 may be greater than the width of the fourth circuit 240, and the cross section of the fourth pad 440 may be nearly circular of.

The third via 330 may be in contact with the fourth pad 440. Specifically, the upper surface of the third via 330 may be in contact with the lower surface of the fourth pad 440. In addition, as described above, the through via 110b may be in contact with the fourth pad 440.

The melting point of the fourth via 340 may be higher than the melting point of the third via 330. For example, the fourth via 340 may be mainly made of copper, and the third via 330 may be mainly made of tin. In addition, the fourth via 340 may be a plated via formed by plating.

The fourth via 340 may penetrate the fourth insulating layer 140 from the upper surface to the lower surface of the fourth insulating layer 140. The cross-sectional area of the fourth via 340 may (but is not limited to) decrease from the upper surface of the fourth insulating layer 140 toward the lower surface first and then increase.

The fifth circuit 250 may include a fifth pad 450 which may be formed on the lower surface of the third insulating layer 130 to be embedded in the third insulating layer 130, which is similar to the fifth circuit 250. The fifth pad 450 may be formed at an end portion of the wire constituting the fifth circuit 250. The thickness of the fifth pad 450 may be substantially the same as the thickness of the fifth circuit 250, and the width of the fifth pad 450 may be greater than the width of the fifth circuit 250, and the cross section of the fifth pad 450 may be nearly circular of.

The third via 330 may be in contact with the fifth pad 450. Specifically, the lower surface of the third via 330 may be in contact with the upper surface of the fifth pad 450. In addition, the fourth via 340 may be in contact with the fifth pad 450. Specifically, the upper surface of the fourth via 340 may be in contact with the lower surface of the fifth pad 450.

The sixth circuit 260 may include a sixth pad 460, which may be formed on the lower surface of the fourth insulating layer 140 to protrude outward, which is similar to the sixth circuit 260. The sixth pad 460 may be formed at an end portion of the wire constituting the sixth circuit 260. The thickness of the sixth pad 460 may be substantially the same as the thickness of the sixth circuit 260, and the width of the sixth pad 460 may be greater than the width of the sixth circuit 260, and the cross section of the sixth pad 460 may be nearly circular of.

The fourth via 340 may be in contact with the sixth pad 460. Specifically, the lower surface of the fourth via 340 may be in contact with the upper surface of the sixth pad 460.

In an example, the electrical signal can be transmitted through the following route: sixth circuit 260—sixth pad 460—fourth path 340—fifth pad 450—third path 330—fourth pad 440—through path—first Pad 410-first path 310-second pad 420-second path 320-third pad 430-third circuit 230.

At the same time, the third pad 430 and the sixth pad 460 may be coupled to the connection part 500 respectively. The connection member 500 may be a solder bump or a solder ball. Such a connection member 500 is configured to electrically connect the printed circuit board and the electronic device (or external board) and physically join the printed circuit board and the electronic device. In other words, the printed circuit board and the electronic device (or external board) are joined to each other by the connecting member 500.

In an example, the connection member 500 placed on the upper side of the printed circuit board (that is, the connection member 500 coupled to the third pad 430) may be coupled to the electronic device, and the connection placed on the lower side of the printed circuit board The component 500 (ie, the connection component 500 coupled to the sixth pad 460) may be coupled to the external board. In this case, the electrical signal can be transmitted through the following route: external board—connecting member 500—sixth pad 460—fourth path 340—fifth pad 450—third path 330—fourth pad 440—through Via—first pad 410—first via 310—second pad 420—second via 320—third pad 430—connecting component 500—electronic device.

A solder resist layer 600 may be stacked on the lower surface of the fourth insulating layer 140, and a solder resist layer 600 may also be stacked on the upper surface of the second insulating layer 120. The solder resist layer 600 may be configured to protect the sixth circuit 260 and the third circuit 230. At the same time, an opening (or through hole) may be formed in the solder resist layer 600 to partially expose the sixth pad 460 and the third pad 430, and the connection part 500 may be coupled in the opening.

FIG. 3 shows a printed circuit board according to an embodiment of the present invention.

3, a printed circuit board according to an embodiment of the present invention includes an insulating material 100, a first insulating layer 110, a second insulating layer 120, a third insulating layer 130, a fourth insulating layer 140, a first circuit 210, a second The circuit 220, the third circuit 230, the fourth circuit 240, the fifth circuit 250, and the sixth circuit 260, and may further include the through path 100b, the integrated path 350, and the integrated path 360.

Insulating material 100, first insulating layer 110, second insulating layer 120, third insulating layer 130, fourth insulating layer 140, first circuit 210, second circuit 220, third circuit 230, fourth circuit 240, fifth The circuit 250, the sixth circuit 260, and the through via 100b have been described above and therefore will not be described in detail herein.

The integrated via 350 is electrically connected to the first circuit 210 and penetrates the first insulating layer 110 and the second insulating layer 120 as a whole. In addition, the integrated via 350 is electrically connected to the fourth circuit 240 and penetrates the third insulating layer 130 and the fourth insulating layer 140 as a whole.

The melting points of the integrated channel 350 and the integrated channel 360 may be lower than the melting point of the first circuit 210 (or the fourth circuit 240). The integrated channel 350 and the integrated channel 360 may be made of conductive paste. Here, the conductive paste may be a paste containing metal, or a paste made of a conductive polymer but not containing any metal. The metal contained in the paste may be one or more of silver (Ag), tin (Sn), nickel (Ni), and copper (Cu). In an example, the first circuit 210 may be mainly made of copper, and the integrated via 350 and the integrated via 360 may be mainly made of tin. This example of the conductive paste is filled in the through holes and then metallized through the reflow process or the heating/cooling process to become the integrated via 350 and the integrated via 360.

The integrated via 350 is integrated with the first via 310 and the second via 320 described with reference to FIGS. 1 and 2, but does not have pads. In addition, the integrated channel 360 is the third channel 330 and the fourth channel 340 integrated together, but does not have pads.

The integrated via 350 and the integrated via 360 may extend to the opening of the solder resist layer 600. In addition, the integrated channel 350 and the integrated channel 360 can be joined to the connection member 500 without a pad between the integrated channel 350, the integrated channel 360 and the connection member 500.

4 and 5 illustrate a method of manufacturing a printed circuit board according to an embodiment of the present invention.

FIG. 4 illustrates the steps of forming the second circuit 220, the third circuit 230, and the second via 320 on or in the second insulating layer 120, and FIG. 5 illustrates the use of the various components prepared in FIG. 4 ( Hereinafter referred to as "unit substrate") to produce a printed circuit board.

Referring to step (a) in FIG. 4, through holes VH1 are formed in the substrate in which the metal layer M1 is stacked on both surfaces of the second insulating layer 120.

As described above, the second insulating layer 120 may be made of a flexible material such as polyimide. The second insulating layer 120 has been explained in detail above and therefore will not be repeated here. The metal layer M1 may be made of the same metal as the second circuit 220 and the third circuit 230. The metal layer M1 may be used as a seed layer.

The via hole VH1 penetrates both the metal layer M1 and the second insulating layer 120. The through hole VH1 may be formed using, for example, a laser drill, or if necessary, the second insulating layer 120 may be laser drilled to be drilled after partially removing the metal layer M1 using, for example, etching. CO ₂ laser can be used as a laser rig.

The cross-sectional area of the via hole VH1 may first decrease from one surface to the other surface of the second insulating layer 120 and then increase. Specifically, in the case of forming a through hole using a laser drilling machine, the cross-sectional area of the hole may be the largest at the surface where the laser is incident. Therefore, the shape of the via hole VH1 shown in step (a) of FIG. 4 may be formed by radiating laser light on both one surface and the other surface of the second insulating layer 120. However, the present invention is not necessarily limited to this shape. Unlike the shape shown in step (a) of FIG. 4, the cross-sectional area of the through hole may be constant from one surface to the other surface of the second insulating layer 120 to always decrease or increase.

Referring to step (b) in FIG. 4, a plating layer may be formed in the via hole VH1. The plating layer may be formed only in the through hole VH1, or may be formed not only in the through hole VH1 but also on the surface of the metal layer M1. The plating layer may be made of the same metal as the metal layer M1. Although an interface may be formed between the plating layer and the metal layer M1, the interface is not shown in FIG. 4.

Referring to step (c) in FIG. 4, circuits are formed on both surfaces of the second insulating layer 120. A second circuit 220 is formed on one surface (ie, lower surface) of the second insulating layer 120, and a third circuit 230 is formed on the other surface (ie, upper surface) of the second insulating layer 120. At the same time, the second pad 420 is formed together with the second circuit 220, and the third pad 430 is formed together with the third circuit 230.

The second circuit 220 and the third circuit 230 may be formed by a roll-to-roll equipment through a subtraction technique or a tenting technique. In the case where the plating layer is formed only in the via hole VH1, the metal layer M1 is etched to form the second circuit 220 and the third circuit 230. In the case where the plating layer is formed not only in the via hole VH1 but also on the surface of the metal layer M1, the metal layer M1 and the plating layer are etched together to form the second circuit 220 and the third circuit 230.

In the case of forming a circuit by a subtractive technology or a cover hole technology, the circuits can each have a precise pitch, and the manufacturing cost of the circuit can be reduced. At the same time, when a circuit is formed using a subtractive technique or a cover hole technique, the side of the circuit may be inclined, and the cross-sectional area of each of the circuits may decrease outward.

Referring to step (a) in FIG. 5, the first circuit 210 is formed. The first circuit 210 may be formed by subtractive technology, cap hole technology, SAP (semi-additive process) technology or MSAP (modified semi-additive process) technology.

Specifically, a detach core (or carrier) D is provided, and the first circuit 210 is formed on one surface of the detach core D.

The detachable core D is a finally removable substrate, and metal layers may be formed on both surfaces of the insulating material layer. In addition, the metal layers may each include a carrier metal layer and a seed metal layer S, where the carrier metal layer is stacked on the insulating material layer and the seed metal layer S is stacked on the carrier metal layer. The thickness of the carrier metal layer may be smaller than the thickness of the seed metal layer S. In step (a), FIG. 5 shows only the seed metal layer S, not the carrier metal layer.

One of the advantages of using a removable core is that two printed circuit boards can be manufactured simultaneously. That is, as explained in step (a) of FIG. 5, in addition to disassembling one surface of the core D, a circuit that is the same as or similar to the first circuit 210 may be formed on the other surface of the disassembling core D. In this case, the carrier metal layer and the seed metal layer S are stacked on both surfaces of the detachable core D.

According to the subtractive technique or the capping technique, the first circuit 210 may be formed by forming a plating layer on the seed metal layer S and then selectively etching the plating layer corresponding to the resist pattern. In addition, according to the SAP technology or the MSAP technology, the first circuit 210 may be formed by performing selective plating on the seed metal layer S corresponding to the pattern of the plating resist.

The first pad 410 can also be formed using the same technique as the first circuit 210.

Referring to step (b) in FIG. 5, the first insulating layer 110 is stacked on the detachable core D. The first insulating layer 110 covers the first circuit 210. The first circuit 110 may be laminated on one surface of the detachable core D, and an insulating layer that is the same as or similar to the first insulating layer 110 may also be laminated on the other surface of the detachable core D.

A through hole VH2 is formed in the first insulating layer 110 to partially expose the first pad 410. A laser drill can be used to form the through hole VH2. CO ₂ laser can be used as a laser rig. The cross-sectional area of the through hole VH2 may decrease inward.

Referring to step (c) in FIG. 5, the conductive paste P is filled in the via hole VH2. The conductive paste can be squeezed into the through hole VH2. The melting point of the conductive paste P may be lower than the melting point of the first circuit 210.

Referring to step (d) in FIG. 5, the unit substrate manufactured through the steps illustrated in FIG. 4 is laminated on the first insulating layer 110. The second pad 420 of the unit substrate may be positioned on the upper surface of the conductive paste P.

The unit substrate may be stacked on the first insulating layer 110 under pressure in a high-temperature environment, and the pressing may be performed at a temperature higher than the melting point of the conductive paste P and lower than the melting point of the first circuit 210. In this case, only the conductive paste P is melted, and the first circuit 210 and the second circuit 220 are not melted, and the conductive paste P is hardened to become the first passage 310 during cooling. In a series of steps, the conductive paste P serves as an adhesive for the first circuit 210 and the second circuit 220.

In addition, through the step shown in (d) of FIG. 5, the second circuit 220 and the second pad 420 are embedded in the first insulating layer 110. For this reason, when the step shown in (d) of FIG. 5 starts, the first insulating layer 110 may be in the B stage.

Referring to step (e) in FIG. 5, the detachable core D is removed. The detachment core D may be removed by first removing a portion other than the seed metal layer S and then etching away the seed metal layer S. Specifically, after first separating the carrier metal layer and the seed metal layer S from each other and then retaining the seed metal layer S where it will become part of the printed circuit board, it is removed by a separate step (ie, etching) Seed metal layer S. When the seed metal layer S is etched, the lower surface of the first circuit 210 (ie, the surface on the side where the core is detached) may be partially etched.

Referring to step (f) in FIG. 5, the solder resist layer 600 is stacked on the first insulating layer 110 and the second insulating layer 120, and a via hole VH3 is formed in the solder resist layer 600. The via hole VH3 may be formed through a lithography process, which includes exposure and development. The through hole VH3 may expose a portion of the first pad 410 and a portion of the third pad 430.

Referring to step (g) in FIG. 5, the connection member 500 (such as a solder bump or a solder ball) is coupled into the through hole VH3. The connecting member 500 can be engaged with the first pad 410 and the third pad 430.

6 shows a method of manufacturing a printed circuit board according to an embodiment of the present invention. The method shown in FIG. 6 is another method of manufacturing a printed circuit board using the unit substrate manufactured through the steps shown in FIG. 4.

Referring to step (a) in FIG. 6, an insulating material 100 (for example, a double-sided copper-clad laminate) having a metal layer M2 laminated on both surfaces is provided, and a through hole VH4 is formed in the insulating material. The through hole VH4 may be formed using, for example, a laser drill.

Referring to step (b) in FIG. 6, a through via 100 b is formed in the through hole VH4. In addition, the first circuit 210 and the fourth circuit 240 are formed on the surface of the insulating material 100. The first pad 410 and the fourth pad 440 are also formed simultaneously with the first circuit 210 and the fourth circuit 240.

Referring to step (c) in FIG. 6, the first insulating layer 110 and the third insulating layer 130 are laminated on the insulating material 100, and through holes VH5 and through holes are formed in the first insulating layer 110 and the third insulating layer 130, respectively. Hole VH5'.

Referring to step (d) in FIG. 6, the conductive paste P is filled in the through hole VH5, and the conductive paste P'is filled in the through hole VH5'. The conductive paste P and the conductive paste P'may be pressed into the through holes VH5 and VH5'. The melting point of the conductive paste P and the conductive paste P'may be lower than the melting point of the first circuit 210 (or the fourth circuit 240).

Referring to step (e) in FIG. 6, the unit substrate is stacked on each of the first insulating layer 110 and the third insulating layer 130. The unit substrate can be manufactured through the steps shown in FIG. 4. The first insulating layer 110 may be stacked with the unit substrate including the second insulating layer 120, and the third insulating layer 130 may be stacked with the unit substrate including the fourth insulating layer 140. When the unit substrates are stacked, the second pad 420 corresponds to the conductive paste P, and the fifth pad 450 corresponds to the conductive paste P'.

The unit substrate can be laminated on each of the first insulating layer 110 and the third insulating layer 130 under high temperature environment, and the pressure can be higher than the melting point of the conductive paste P and the conductive paste P'and lower than The temperature of the melting point of the first circuit 210 (or the fourth circuit 240) is performed. In this case, only the conductive paste P and the conductive paste P'are melted, and the first circuit 210 (or the fourth circuit 240) is not melted, and the conductive paste P is hardened to become the first passage 310 during cooling. And during the cooling period, the conductive paste P′ is hardened to become the third via 330.

In addition, the second circuit 220 is embedded in the first insulating layer 110 and the fifth circuit 250 is embedded in the third insulating layer 130.

Referring to step (f) in FIG. 6, the solder resist layer 600 is stacked on each of the second insulating layer 120 and the fourth insulating layer 140, and a via hole VH6 is formed in the solder resist layer 600. The via hole VH6 may be formed through a lithography process including exposure and development. The through hole VH6 may expose a portion of the third pad 430 and a portion of the sixth pad 460.

Referring to step (g) in FIG. 6, the connection member 500 (such as a solder bump or a solder ball) may be coupled into the through hole VH6. The connecting member 500 can be engaged with the third pad 430 and the sixth pad 460. The connection member 500 may be formed by inserting solder material into the through hole VH6 and then performing a reflow process.

7 and 8 illustrate a method of manufacturing a printed circuit board according to an embodiment of the present invention.

7 shows a step of forming a unit substrate different from the unit substrate shown in FIG. 4, and FIG. 8 shows a step of manufacturing a printed circuit board using the unit substrate prepared through the steps shown in FIG. 7.

Referring to FIG. 7, the second circuit 220 and the third circuit 230 are formed on the second insulating layer 120, and the through hole VH7 is formed in the second insulating layer 120. Vias are not used to fill vias VH7.

Step (a) in FIG. 8 is the same as step (a) in FIG. 6, and step (b) in FIG. 8 is the same as step (b) in FIG. 6.

Referring to step (c) and step (d) in FIG. 8, the first insulating layer 110 and the third insulating layer 130 are laminated on both surfaces of the insulating material 100, and are respectively insulated on the first insulating layer 110 and the third insulating layer 100 In the layer 130, a via hole VH5 and a via hole VH5' are formed. The first insulating layer 110 and the third insulating layer 130 each of which includes the metal layer M3 may be first stacked on the insulating material 110, and then may be formed by, for example, etching after forming the vias VH5, VH5' Remove the metal layer M3.

Referring to step (e) in FIG. 8, the unit substrate is stacked on each of the first insulating layer 110 and the third insulating layer 130. Here, the via hole VH7 formed in the second insulating layer 120 corresponds to the via hole VH5 formed in the first insulating layer 110, and the via hole VH7' formed in the fourth insulating layer 140 corresponds to the third hole formed in the third The through hole VH5' in the insulating layer 130.

Referring to step (f) in FIG. 8, a solder resist layer 600 is formed on each of the second insulating layer 120 and the fourth insulating layer 140, and then the solder resist layer 600 is formed with the exposed third pad 430 After the opening of the sixth pad 460, the conductive paste P is entirely filled in the openings of the via holes VH5, VH7, and the solder resist layer 600. In addition, the conductive paste is entirely filled in the openings of the via holes VH5', the via holes VH7', and the solder resist layer 600. The integrally filled conductive paste is melted and then cooled to become the integrated channel 350 and the integrated channel 360.

Referring to step (g) in FIG. 8, the connection member 500 (such as a solder bump or a solder ball) is coupled to the integrated via 350 and the integrated via 360.

Although the present invention includes specific examples, those skilled in the art should understand that various changes in form and details can be made to these examples without departing from the spirit and scope of the scope of the patent application and its equivalents. The examples described in this article should only be regarded as illustrative and not for restrictive purposes. The description of the features or aspects in each instance should be considered applicable to similar features or aspects in other instances. This can be achieved if the techniques are performed in a different order, and/or if the components in the system, architecture, device, or circuit are replaced or supplemented in different ways and/or by other components or their equivalents Appropriate results. Therefore, the scope of the present invention is not defined by the detailed description, but by the scope of the patent application and its equivalent forms, and all changes within the scope of the patent scope and its equivalent forms should be understood to include In the present invention.

100‧‧‧Insulation material 100a‧‧‧reinforcement 100b‧‧‧Through the passage 110‧‧‧First insulation layer 120‧‧‧Second insulation layer 130‧‧‧The third insulating layer 140‧‧‧ Fourth insulation 210‧‧‧ First Circuit 220‧‧‧ Second circuit 230‧‧‧ Third Circuit 240‧‧‧ Fourth Circuit 250‧‧‧ fifth circuit 260‧‧‧Sixth circuit 310‧‧‧ First Path 320‧‧‧Second access 330‧‧‧The third channel 340‧‧‧ Fourth Path 350, 360‧‧‧Integrated access 410‧‧‧ First pad 420‧‧‧Second pad 430‧‧‧The third pad 440‧‧‧The fourth pad 450‧‧‧ fifth pad 460‧‧‧Sixth pad 500‧‧‧Connecting parts 600‧‧‧solder mask (A), (b), (c), (d), (e), (f), (g) ‧‧‧ steps D‧‧‧Disassembled core M1, M2, M3 ‧‧‧ metal layer P, P’‧‧‧ conductive paste S‧‧‧Seed metal layer VH1, VH2, VH3, VH4, VH5, VH5’, VH6, VH7, VH7’‧‧‧Through hole

FIG. 1 shows a printed circuit board according to an embodiment of the present invention. 2 shows a printed circuit board according to an embodiment of the present invention. FIG. 3 shows a printed circuit board according to an embodiment of the present invention. 4 and 5 illustrate a method of manufacturing a printed circuit board according to an embodiment of the present invention. 6 shows a method of manufacturing a printed circuit board according to an embodiment of the present invention. 7 and 8 illustrate a method of manufacturing a printed circuit board according to an embodiment of the present invention.

110‧‧‧First insulation layer

120‧‧‧Second insulation layer

210‧‧‧ First Circuit

220‧‧‧ Second circuit

230‧‧‧ Third Circuit

310‧‧‧ First Path

320‧‧‧Second access

410‧‧‧ First pad

420‧‧‧Second pad

430‧‧‧The third pad

500‧‧‧Connecting parts

600‧‧‧solder mask

Claims (19)

A printed circuit board, including: First insulating layer; A second insulating layer made of flexible material and laminated on the first insulating layer; A first circuit formed on the lower surface of the first insulating layer and embedded in the first insulating layer; A second circuit formed on the lower surface of the second insulating layer and stacked in the first insulating layer; and A third circuit formed on the upper surface of the second insulating layer, The pitch of the second circuit is smaller than the pitch of the first circuit. The printed circuit board according to item 1 of the patent application scope, wherein the pitch of the third circuit is smaller than the pitch of the first circuit. The printed circuit board according to item 1 of the patent application scope, wherein the third circuit protrudes outward on the upper surface of the second insulating layer. The printed circuit board according to item 1 of the patent application scope, wherein the first insulating layer is made of a rigid material. The printed circuit board according to item 1 of the scope of patent application further includes: A first via that penetrates the first insulating layer and is configured to electrically connect the first circuit and the second circuit; and The second via penetrates the second insulating layer and is configured to electrically connect the second circuit and the third circuit. The printed circuit board according to item 5 of the patent application range, wherein the melting point of the first via is lower than the melting point of the first circuit. The printed circuit board according to item 5 of the patent application range, wherein the melting point of the first via is lower than the melting point of the second via. The printed circuit board according to item 5 of the patent application scope, wherein the first pad is coupled to the lower surface of the first via, Wherein the second pad is coupled to the lower surface of the second path, The third pad is coupled to the upper surface of the second path, Wherein the first pad and the second pad are embedded in the first insulating layer, and The third pad protrudes outward from the upper surface of the second passage. The printed circuit board according to item 8 of the patent application range, wherein the connection member is coupled to each of the first pad and the third pad. The printed circuit board according to item 1 of the patent application scope further includes a solder resist layer laminated on the lower surface of the first insulating layer and the upper surface of the second insulating layer on. The printed circuit board according to item 1 of the scope of the patent application further includes an insulating material, the insulating material is laminated on the lower surface of the first insulating layer, The first circuit is located on the upper surface of the insulating material. The printed circuit board according to item 11 of the patent application scope, wherein the insulating material contains a reinforcing material. According to the printed circuit board described in item 11 of the patent application scope, it further includes: A third insulating layer laminated on the lower surface of the insulating material and made of a rigid material; and The fourth insulating layer is laminated on the lower surface of the third insulating layer and is made of a flexible material. According to the printed circuit board described in item 13 of the patent application scope, it further includes: A fourth circuit formed on the lower surface of the insulating material to be embedded in the third insulating layer; and A fifth circuit formed on one surface of the fourth insulating layer to be embedded in the third insulating layer, The pitch of the fifth circuit is smaller than the pitch of the fourth circuit. The printed circuit board according to item 14 of the scope of the patent application further includes a sixth circuit formed on the other surface of the fourth insulating layer to protrude outward to be positioned in line with the The fifth circuit is opposite, The pitch of the sixth circuit is smaller than the pitch of the fourth circuit. The printed circuit board according to item 14 of the patent application scope further includes a through-hole, the through-hole penetrates the insulating material to electrically connect the first circuit and the fourth circuit. The printed circuit board according to item 13 of the patent application scope further includes a solder resist layer laminated on the upper surface of the second insulating layer and the lower surface of the fourth insulating layer. The printed circuit board according to item 11 of the scope of the patent application further includes a via, which entirely penetrates the first insulating layer and the second insulating layer to be electrically connected to the first circuit. The printed circuit board of claim 18, wherein the melting point of the via is lower than the melting point of the first circuit.

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