TWI405520B - Method for manufacturing printed circuit board - Google Patents

Abstract

A method for manufacturing a printed circuit board includes steps below. Firstly, an inner substrate, a first copper clad laminate, and a first adhesive layer are provided. The first copper clad laminate includes a first product region, a first non-product region, and a first blank region waited to be removed. Portion of the first removing region adjoins the first production region; other portion of the first removing region adjoins the first non-production region. Secondly, a first opening is defined along an imaginary boundary line of the first blank region and the first production region. Thirdly, a first through hole is defined in the first adhesive layer. The first through hole is corresponding to the first blank region. Fourthly, the first adhesive layer and the first copper clad laminate are stacked and laminated on the inner substrate. Fifthly, first electrically conductive circuits are formed in the first copper clad laminate. Sixthly, a second opening is defined along an imaginary boundary line of the first blank region and the first non-production region, thereby a second through hole communicating with the first through hole is defined in the first copper clad laminate and a material of the first blank region is removed.

Description

Circuit board manufacturing method

The present invention relates to the field of circuit board fabrication, and more particularly to a method for producing a flat flexible circuit board.

Printed circuit boards are widely used due to their high assembly density. For application of the circuit board, please refer to the literature Takahashi, A.Ooki, N.Nagai, A.Akahoshi, H.Mukoh, A.Wajima,M.Res.Lab.,High density multilayer printed circuit board for HITAC M-880,IEEE Trans. on Components, Packaging, and Manufacturing Technology, 1992, 15(4): 418-425.

Due to the demand for miniaturization of electronic devices, the size of the circuit board package used in electronic devices becomes smaller. A recess is formed in the area of the circuit board where no wiring is provided, and the recess is used to cooperate with other packaged or plugged electronic components, thereby reducing the space occupied by the entire circuit board package. However, the above-mentioned grooves need to form corresponding openings in each layer of the circuit board in the manufacturing process, and then press-fit and circuit fabrication steps, so that the corresponding areas of the openings are prone to the problem of inconsistent expansion and contraction during the manufacturing process of the circuit board. Wrinkles, which affect the yield of circuit board products.

In view of this, it is necessary to provide a manufacturing method capable of fabricating a circuit board having a good flatness.

A method of fabricating a circuit board will be described below by way of example.

A method of manufacturing a circuit board, comprising the steps of: providing an inner substrate, a first copper clad plate and a first adhesive layer. The first copper clad board includes a first product area, a first non-product area, and a first removal area. The first removal region portion is adjacent to the first product region, and the other portion of the first removal region is adjacent to the first non-product region. The first copper clad laminate has a first copper foil layer. The inner substrate has a first surface. A first opening is formed along an intersection of the first removal region and the first product region such that the first removal region is separated from the first product region. A first through hole corresponding to the first removal region is formed in the first adhesive layer. The first adhesive layer and the first copper clad laminate are sequentially stacked on the first surface of the substrate, and the first adhesive layer, the first copper clad laminate and the inner layer substrate are pressed. Forming a first conductive line on the first copper foil layer of the first copper clad laminate. A second opening is formed along the intersection of the first removal region and the first non-product region. The second opening and the first opening communicate with each other to remove the material copper clad plate of the first removal region, thereby forming a second through hole corresponding to the first removal region in the first copper clad plate.

Compared with the prior art, in the circuit board manufacturing method provided in this embodiment, an opening is formed between the removed region in the first copper clad laminate and the second copper clad laminate and the product region before the pressing and the fabrication of the conductive circuit, and the removal region is formed. Separating from the product area and communicating with the non-product area, the removal area is removed after forming the conductive line, thereby avoiding the rise of the pressing and the production of the conductive line. The board product caused by the inconsistency caused by the wrinkles of the board is poor.

101‧‧‧ Groove

110‧‧‧ Inner substrate

111‧‧‧ Inner copper foil layer

112‧‧‧Inner insulation

113‧‧‧ first surface

114‧‧‧ second surface

120‧‧‧First CCL

121‧‧‧First copper foil layer

122‧‧‧First insulation

123‧‧‧First non-product area

124‧‧‧First product area

125‧‧‧First removal area

1251‧‧‧ first side

1252‧‧‧ second side

1253‧‧‧ third side

1254‧‧‧ fourth side

126‧‧‧ first opening

127‧‧‧First conductive line

129‧‧‧second through hole

130‧‧‧First layer

131‧‧‧First through hole

160‧‧‧Second CCL

161‧‧‧Second copper foil layer

162‧‧‧Second insulation

163‧‧‧Second non-product area

164‧‧‧Second product area

165‧‧‧Second removal area

1651‧‧‧ fifth side

1652‧‧‧ sixth side

1653‧‧‧ seventh side

1654‧‧‧ eighth side

166‧‧‧ third opening

167‧‧‧Second conductive line

169‧‧‧4th through hole

170‧‧‧Second layer

171‧‧‧ third through hole

180‧‧‧ boards

FIG. 1 is a schematic diagram of an inner layer substrate, a first adhesive layer, and a first copper clad plate provided by an embodiment of the present technical solution.

FIG. 2 is a schematic diagram of a first copper clad plate provided by an embodiment of the present technical solution to form a first opening.

FIG. 3 is a schematic view showing the first adhesive layer formed by the first adhesive layer provided by the embodiment of the present technical solution.

FIG. 4 is a schematic diagram of the stacked and laminated substrate, the first adhesive layer and the first copper clad plate provided by the embodiment of the present technical solution.

Figure 5 is a schematic cross-sectional view taken along line V-V of Figure 4.

FIG. 6 is a schematic diagram of the embodiment of the present invention, after the substrate is formed to form a conductive line and the first copper clad plate forms a first conductive line.

FIG. 7 is a schematic diagram of a second copper clad plate and a second rubber layer provided by an embodiment of the present technical solution.

FIG. 8 is a schematic diagram of the second copper clad plate after forming a third opening according to an embodiment of the present technical solution.

FIG. 9 is a schematic view of the embodiment of the present invention after the second adhesive layer is formed into a third through hole.

FIG. 10 is a schematic diagram of the embodiment of the present invention provided on the circuit board after stacking and pressing the second adhesive layer and the second copper clad laminate.

FIG. 11 is a schematic diagram of the second copper clad board after forming a second conductive line according to an embodiment of the present technical solution.

12 is a schematic diagram of a circuit board fabricated in an embodiment of the present technical solution.

The method for fabricating the circuit board provided by the technical solution is further described below with reference to the accompanying drawings and embodiments.

The circuit board manufacturing method provided by the technical solution includes the following steps: First, referring to FIG. 1, an inner substrate 110, a first copper clad 120 and a first adhesive layer 130 are provided.

In this embodiment, the inner substrate 110 is a copper clad laminate, and the inner substrate 110 includes an inner insulating layer 112 and an inner copper foil layer 111 formed on the inner insulating layer 112. The inner substrate 110 has opposing first and second surfaces 113, 114. The inner substrate 110 may also be a two-layer or multi-layer circuit substrate on which conductive lines are formed.

The first copper clad laminate 120 includes a first insulating layer 122 and a first copper foil layer 121 formed on the first insulating layer 122. The inner substrate 110 and the first copper clad layer 120 are insulated from the layer of the first copper clad plate 120. Polyethyleneimine, polyethylene terephthalate, polytetrafluoroethylene, polythioamide, polymethyl methacrylate commonly used in the art. Made of materials such as esters, polycarbonates or polyimine-polyethylene-terephthalate copolymers. The first adhesive layer 130 may be made of epoxy resin or acrylic.

The first copper clad 120 includes a first non-product area 123, a first product area 124, and a first removal area 125. The first non-product area 123 is an area in which no conductive line is formed in the area, and the first product area 124 means that a guide needs to be set. The area of the electrical line. The first removal region 125 is the region that will be removed in a subsequent process such that the corresponding locations of the fabricated circuit board form a recess. The first removal region 125 is partially adjacent to the first product region 124 and the other portions are adjacent to the first non-product region 123. In this embodiment, the first removal area 125 is a rectangle, and includes a first side 1251, a second side 1252, a third side 1253, and a fourth side 1254 which are sequentially connected, wherein the first side 1251 and the first non-product area 123 is adjacent, and the other three sides are adjacent to the first product area 124.

The shape of the first removal region 125 corresponds to the shape of the groove cross-section of the circuit board to be formed, and may also be a circular or polygonal shape having at least a portion adjacent to the first product region 124.

In the second step, referring to FIG. 2 and FIG. 3 together, a first opening 126 is formed between the first removal region 125 and the first product region 124.

The first opening 126 is formed along the second side 1252, the third side 1253 and the fourth side 1254 of the first removal region 125 by punching or cutting, so that the first removal region 125 and the first product region 124 are not Connected. The first side 1251 of the first removal region 125 is still interconnected with the first non-product region 123.

In the third step, a first through hole 131 corresponding to the first removal region 125 is formed in the first adhesive layer 130.

A plurality of first through holes 131 corresponding to the first removal regions 125 are formed in the first adhesive layer 130 by punching or cutting. Preferably, the shape of the cross section of the first through hole 131 is the same as the shape of the corresponding first removal area 125, and the area of the cross section of the first through hole 131 is slightly larger than the area of the first removal area 125.

In the fourth step, referring to FIG. 4 and FIG. 5, the first adhesive layer 130 and the first copper clad 120 are sequentially stacked on the inner insulating layer 112 of the inner substrate 110, and the inner substrate 110 is pressed. The glue layer 130 and the first copper clad plate 120.

The first adhesive layer 130 and the first copper clad 120 are sequentially stacked on the inner insulating layer 112 side of the inner substrate 110, that is, on the first surface 113, so that the first insulating layer 122 of the first copper clad 120 and the first adhesive The layers 130 are adjacent to each other such that the first vias 131 in the first adhesive layer 130 correspond to the first removed regions 125 of the first copper clad 120 in a direction perpendicular to the plane of the inner substrate 110.

After the stacked inner substrate 110, the first adhesive layer 130 and the first copper clad plate 120 are heated and pressurized, since the first adhesive layer 130 has adhesiveness, it is bonded and solidified on the inner substrate 110 and the first copper clad plate 120, The pressing causes the inner substrate 110, the first adhesive layer 130 and the first copper clad layer 120 to form a flat whole structure.

When the inner substrate 110 is a double-layer or multi-layer substrate on which the conductive lines are formed, the first adhesive layer 130 and the first copper-clad laminate 120 may be pressed on the inner surface of the inner substrate 110 opposite to the first surface 113 and the second surface 114.

In the fifth step, referring to FIG. 6, a conductive line 115 is formed in the inner copper foil layer 111 of the inner substrate 110, and a first conductive line 127 is formed in the first copper foil layer 121 of the first copper clad 120.

In this embodiment, the conductive line 115 is formed in the inner copper foil layer 111 of the inner substrate 110 by the image transfer process-etching process, and the first conductive layer is formed in the first copper foil layer 121 of the first copper clad layer 120. Line 127.

When the inner substrate 110 is a double-layer or multi-layer substrate on which conductive lines are formed, In this step, it is not necessary to form a conductive line in the inner substrate 110.

In the sixth step, referring to FIG. 7, a second copper clad plate 160 and a second adhesive layer 170 are provided.

The second copper clad laminate 160 is identical in structure to the first copper clad laminate 120. The second copper clad laminate 160 is composed of a second copper foil layer 161 and a second insulating layer 162. The second copper clad laminate 160 includes a second non-product region 163 and a second portion. The product area 164 and the second removal area 165 have the same shape and the same size as the first removal area 125. The second removal region 165 is also rectangular, and has a fifth side 1651 adjacent to the second non-product area 163, and a sixth side 1652, a seventh side 1653, and an eighth side adjacent to the second product area 164. 1654. The second adhesive layer 170 has the same structure as the first adhesive layer 130.

In the seventh step, referring to FIGS. 9 to 10, a third opening 166 is formed between the second removal region 165 and the second product region 164.

The third opening 166 is formed along the sixth side 1652, the seventh side 1653, and the eighth side 1654 of the second removal region 165 by punching or cutting, so that the second removal region 165 and the second product region 164 are not Connected. The fifth side 1651 of the second removal region 165 is still interconnected with the second product region 164.

In the eighth step, a third through hole 171 corresponding to the second removal region 165 is formed in the second adhesive layer 170.

A plurality of third through holes 171 corresponding to the second removal regions 165 are formed in the second adhesive layer 170 by punching or cutting. Preferably, the shape of the cross section of the third through hole 171 is the same as the shape of the corresponding second removal region 165, and the area of the cross section of the third through hole 171 is slightly larger than the area of the second removal region 165.

In the ninth step, referring to FIG. 10, the second adhesive layer 170 and the second copper clad laminate 160 are sequentially stacked and pressed onto the first conductive line 127, and the second insulating layer 162 of the second copper clad laminate 160 is second and second. The glue layers 170 are adjacent.

First, the second adhesive layer 170 and the second copper clad laminate 160 are sequentially stacked and pressed onto the first conductive line 127 such that the second insulating layer 162 of the second copper clad laminate 160 is adjacent to the second adhesive layer 170, and The third through holes 171 and the second removal regions 165 correspond to each other in a direction perpendicular to the first adhesive layer 130 and are coaxially disposed. Then, the second adhesive layer 170 and the second copper clad laminate 160 are pressed onto the first conductive line 127 by heating and pressing.

In the tenth step, referring to FIG. 11, a second conductive line 167 is formed in the second copper foil layer 161 of the second copper clad laminate 160.

A second conductive line 167 is formed in the second copper foil layer 161 in the same manner as the first conductive line 127 is formed.

In the eleventh step, referring to FIG. 2, FIG. 8 and FIG. 12, the first removal area 125 and the second removal area 165 are removed, thereby obtaining a circuit board 180.

A fourth opening is formed along the sixth side 1652, the seventh side 1653 and the eighth side 1654 of the second removal region 165 by means of punching or cutting, and the fourth opening and the third opening 166 are connected to the fourth opening. The second removal region 165 and the second non-product region 163 are separated from each other, and the second removal region 165 is removed. After the second removal region 165 is removed, a fourth through hole 169 is formed in the second copper clad plate 160, and the fourth through hole 169 and the third through hole 171 communicate with each other.

Along the second side 1252, the third side 1253 and the fourth side of the first removal area 125 1254 forms a second opening, and the second opening communicates with the first opening 126 such that the first removal region 125 is separated from the first non-product region 123 and the first removal region 125 is removed. After the first removal region 125 is removed, the second through hole 129 is formed in the first copper clad plate 120, and the second through hole 129 and the third through hole 171, the first through hole 131, and the fourth through hole 169 are connected to each other to form a concave shape. The slot 101, thereby obtaining a circuit board 180 having a recess 101. In this step, since the first removal region 125 and the second removal region 165 correspond to each other, the second opening and the fourth opening may be simultaneously formed by one cutting or punching. It is also possible to perform a punching or cutting to form a fourth opening, and then perform a punching or cutting to form a third opening. The cutting method can be mechanical cutting or laser cutting.

The circuit board manufacturing method provided in this embodiment can be pressed on one side of the second conductive line 167 to form a glue layer having a through hole and having the same layer before the first removal area 125 and the second removal area 165 are removed. A copper clad plate corresponding to the removal region of the region 125 is removed, and a conductive line is formed on the copper foil of the copper clad plate, and then the corresponding plurality of removed regions are removed, thereby obtaining a circuit having more layers and a larger groove depth. board.

When the inner substrate 110 is a double-layer or multi-layer circuit substrate, a glue layer and a copper clad plate are formed on the opposite surfaces thereof, and then the removed region is removed, thereby obtaining a circuit board having both sides of the groove.

In the method for manufacturing a circuit board provided in this embodiment, an opening is formed between the removed region in the first copper clad laminate and the second copper clad laminate and the product region, and the removed region is separated from the product region before pressing and forming the conductive circuit. Interconnecting with the non-product area, and removing the removed area after forming the conductive line, thereby It is avoided that the circuit board product is defective due to the wrinkles of the circuit board caused by the inconsistent expansion and contraction when pressing and manufacturing the conductive circuit.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

101‧‧‧ Groove

129‧‧‧second through hole

131‧‧‧First through hole

169‧‧‧4th through hole

171‧‧‧ third through hole

180‧‧‧ boards

Claims (10)

A circuit board manufacturing method includes the steps of: providing an inner substrate, a first copper clad plate and a first adhesive layer, wherein the first copper clad plate comprises a first product region, a first non-product region and a first removal region, the first The removal region portion is adjacent to the first product region, and the other portion of the first removal region is adjacent to the first non-product region, the first copper clad laminate comprises a first copper foil layer, and the inner layer substrate has a first Forming a first opening along the intersection of the first removal region and the first product region such that the first removal region is separated from the first product region, and the first removal region is interconnected with the first non-product region; Forming a first through hole corresponding to the first removal region in the adhesive layer; sequentially stacking the first adhesive layer and the first copper clad plate on the first surface of the substrate, and pressing the first adhesive layer, the first copper clad plate and the inner layer Forming a first conductive line on the first copper foil layer of the first copper clad plate; forming a second opening along the intersection of the first removal area and the first non-product area, the second opening and the first opening communicating with each other To the first copper Removing material of the first area to be removed, thereby forming a first region corresponding to the removal of the second through-hole in the first CCL. The method of fabricating a circuit board according to claim 1, wherein the inner substrate is a copper clad laminate, and the inner substrate has an inner copper foil layer on a side opposite to the first surface, The first copper foil layer of the copper clad layer forms a first conductive line while forming a conductive line in the inner layer copper foil layer. The method of manufacturing a circuit board according to claim 1, wherein the inner substrate is a double-layer or multi-layer circuit substrate on which a conductive line is formed, and the inner substrate has a second surface opposite to the first surface. And pressing the first adhesive layer and the first copper clad laminate on the second surface when the first adhesive layer is pressed on the first surface. The circuit board manufacturing method of claim 1, wherein the circuit board manufacturing method further comprises: providing a second copper clad plate and a second glue layer after forming the first conductive line, the second cover The copper plate includes a second product area and a second non-product area, the second non-product area includes a second removal area, the second removal area portion is adjacent to the second product area, and the second removal area and the first removal area Correspondingly, the second copper clad laminate has a second copper foil layer; a third opening is formed along the intersection of the second removal region and the second product region, so that the second removal region and the second product region are separated from each other; Forming a third through hole corresponding to the second removal region in the second adhesive layer; sequentially stacking and pressing the second adhesive layer and the second copper clad plate on the first conductive line; and forming the second copper on the second copper clad plate Forming a second conductive line in the foil layer; forming a fourth opening along the intersection of the second removal area and the second non-product area before or at the same time, the fourth opening and the third opening are in communication with each other, Take The material of the second copper clad plate in the second removal region is removed, so that a fourth through hole corresponding to the first through hole, the second through hole and the third through hole is formed in the second copper clad plate. The method of fabricating a circuit board according to claim 4, wherein the first copper clad plate comprises a plurality of first removal regions. The method for fabricating a circuit board according to claim 5, wherein the second copper clad plate includes a plurality of second removal regions, and the plurality of first removal regions are in one-to-one correspondence with the plurality of second removal regions. The method for fabricating a circuit board according to claim 1, wherein the first opening is formed in the first copper clad plate along the intersection of the first removal region and the first product region by a punching or cutting method. The method of manufacturing a circuit board according to the seventh aspect of the invention, wherein the cutting method is laser cutting or mechanical cutting. The circuit board manufacturing method according to claim 1, wherein the first through hole has the same shape and coaxial arrangement as the first removal region, and the cross-sectional area of the first through hole is larger than the area of the first removal region. The method of fabricating a circuit board according to the first aspect of the invention, wherein the second opening is formed along a line of intersection of the first removal region and the first non-product region by means of punching or cutting.