TWI303541B - Electrically connecting method for blind holes of printed circuit board - Google Patents

Description

•1303541

TECHNICAL FIELD OF THE INVENTION The invention relates to a method for blind hole conduction of a printed circuit board, in particular, a blind hole in a printed circuit board is plated by an auxiliary method, and is shielded by an auxiliary shield. A method of forming a plated through-hole in the blind hole and raising the blind hole conducting method of the printed circuit board of the blind hole conduction quality is formed. [Prior Art] A blind hole conducting method for driving a printed circuit board, as shown in the figure, includes an insulating layer 1 and two conductive layers 2. The insulating layer is formed as a substrate, and the layer 2 is formed on both sides of the insulating layer 1. The insulating layer 1 of the two conductive layers 2 is formed by drilling a blind hole. The walls of the blind holes are first formed into a conductive layer 12 by sputtering or vapor deposition chemistry or other chemical vapor deposition. Then, a plating layer 21 is formed by common deposition on the electric layer 2 in the blind via and its open end. In the electroplating process, the upper layer 12 can accelerate the deposition efficiency of the key in the blind hole 11 to improve the process efficiency of the printed circuit board. The conduction layer 12 of the open end of the blind hole 11 often forms a large current collection density with respect to the interface of the conductive layer 2, so that the plating layer 21 is deposited at a relatively fast speed in the blind hole. The opening. As a result, the design of the conductive layer 12 causes the interstitial in the blind via 11 to be incomplete, and the closed via 22 is easily formed in the blind via 11 . When the printed circuit board has too many holes 2 2 remaining, it is bound to affect the interlayer conduction quality of the blind holes 11 and even reduce the yield of the product. For the above reasons, it is still necessary to further improve the blind hole conduction method of the above printed circuit board. In view of the above, the present invention improves the above disadvantages by utilizing a blind hole

C:\Logo-5\Five Continents\PK9781. ptd Page 8.1303541 V. INSTRUCTIONS (2) A conductive layer at the closed end is used as the electrode of the electroplating process, and the opening of the blind hole is appropriately covered by a protective cover Another conductive layer on the outer edge of the end. Thereby, it is ensured that the protective cover controls the formation of a plating via, and the plating via can be selected to form a bump as a solder or an input/output terminal. Therefore, the present invention can indeed omit the conventional conduction layer forming step for effectively reducing the probability of blind holes forming poor holes, thereby improving the interlayer conduction quality of the blind holes and simplifying the process of the conductive terminals. SUMMARY OF THE INVENTION The main object of the present invention is to provide a blind via conducting method for a printed circuit board, which utilizes a conductive layer of a closed end of a blind via as an electrode of an electroplating process so that the blind via is formed by the conductive layer Initiating electroplating deposition to form an electroplated via body' has the effect of improving the inter-layer conduction quality of the blind via. A secondary object of the present invention is to provide a blind via conduction method for a printed circuit board, which utilizes a conductive layer of a closed end of a blind via as an electrode for electroplating. # By properly covering the blind via a protective cover The other end of the open end is electrically conductive I so that the protective cover controls the formation of an electroplated conductive body, so that the present invention has the effect of improving the interlayer conduction quality of the blind via. Another object of the present invention is to provide a blind via conduction method for a printed circuit board, which utilizes a conductive layer of a closed end of a blind via as an electrode of an electroplating process, and appropriately covers an open end of the blind via with a protective cover Another conductive layer on the outer edge, so that the protective cover controls to form a plated through body, and the plated through body is selected to form a bump as a pad or an input/output terminal. [I/O], The invention has the effect of simplifying the process of the conductive terminal. A blind hole conducting method for a printed circuit board according to the present invention, comprising steps

C:\Logo-5\Five Continents\PK9781.ptd * 1303541 V. Description of invention (3) The first side of one of the surface layers forms a first conductive layer, which runs through the side of the insulation I ^ _ Forming at least one blind hole; forming a second conductive layer and a protective cover on the second side of the insulating layer to cover the region of the second conductive layer outside the opening edge of the channel; using the first layer of the insulating layer The first side of the side is an electrode, and an electroplating process is performed to deposit a conductive body in the blind hole; and when the electroplated conductive body accumulates to fill the blind hole, the 'protection cover is removed; The grinding method flattens or forms the plated conductor. Thereby, the blind via uses the electroplated via to form an interlayer conduction. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more apparent and obvious. Referring to FIGS. 2 and SA to FIG. 2, the blind hole conducting method of the first printed circuit of the present invention comprises the steps of: [1] having a conductive layer on one of the first side and the second side of the insulating layer 1, respectively. 2 and 2' in the insulation layer! The second side penetrates the conductive layer 2 to form at least one blind hole 11; [2], and a protective cover 3 is disposed on the second side of the insulating layer i to cover the conductive layer 2'. a region other than the opening edge of the blind hole 11; [3] using the conductive layer 2 on the first side of the insulating layer i as an electrode, and performing an electroplating process to deposit a plating via in the blind via 4; [4], when the plating via 4 is accumulated to fill the open end of the blind hole

1303541 5. After the invention description (4), the protective cover 3 covering the conductive layer 2' is removed; and [5], the plating method is selected to be flattened or made into a convex material 40, thereby The blind via 11 turns on the conductive layers 2 and 2' on both sides of the insulating layer 1 by the plating via 4. Referring to FIG. 2, FIG. 3A and FIG. 3B, the first step of the method for printing the blind hole of the printed circuit board according to the first embodiment of the present invention is: prefabricating on the first side and the second side of the insulating layer 1, respectively. The conductive layers 2 and 2 are formed to form a substrate. The blind hole 11 is formed on the second side of the insulating layer 1 by laser or mechanical drilling. The insulating layer 1 and the conductive layers 2 and 2' are conventional structures of the printed circuit board. The insulating layer 1 is preferably selected from the group consisting of polyamidoamine (PI) and polyester [P 〇 1 yeaster, PET], polyethylene naphtha late (PEN), liquid crystal polymer, [Liquid Crystal Polymer, LCP] or Teflon, Teflon, etc. The conductive layer 2 and 2' is made of a suitable conductive metal, preferably a copper foil layer. The insulating layer 1 and the conductive layers 2 and 2' are combined to have a double-layer copper foil substrate. The second side (upper side) of the insulating layer 1 is The blind hole 11 is formed by laser drilling, and the blind hole 11 is preferably an inverted trapezoidal shape with a wide mouth and a narrow bottom, that is, the blind hole is preferably formed into a trumpet shape for subsequent electroplating deposition. Referring to FIGS. 2 and 3C, the second step of the blind via conducting method of the printed circuit board according to the first embodiment of the present invention is: providing the protective cover 3 on the second side of the insulating layer 1 to cover the conductive layer. 2' is outside the opening edge of the blind hole 11. The protective cover 3 is preferably selected from recyclable Use non-gold «yu cover plate, or optional free photoresist coating or dry film pressing method. No

C:\Logo-5\F i ve Cont i nents\PK9781. ptd Page 11 1303541 V. Description of the Invention (5) The protective cover 3 can be used to effectively cover the conductive layer = the opening edge of the eye opening 11 Outside the area. At the same time, the protective cover 3 forms at least a plating window 31 for the f 3 hole: 1 so as to expose the conductive layer 2, at the opening edge of the blind hole 1 1 , for reference, refer to the figures 2, 30 and 3: , electric bond deposition. The blind hole conduction method of the circuit board is not deposited in the printing hole η of the first embodiment, and the electric recording is formed to 仃 the copper box substrate (that is, the iy4 channel is in the electric ore system). The first side [lower side] of the guide if appropriate. Secondly, 'the insulating layer 1 as an electrode, and then promote; is suitable: sub-connected to the electrolytic cell negative power supply, two gradually from the inside out of the electric deposit The conductive layer 2 forming the electric ore guide is subjected to the electroplating process, and the first side [the lower conductive layer 2 is preferably selected to be only coated with a coating-protective paint [not shown] such as 4 cover 3, or remote selection side of the snow guide? It is planned to prevent the first side [the lower U conductive layer 2 forms redundant plating, please refer to the 2nd, 3rd and 3G diagrams, the female circuit The blind via conduction method of the board is described in the fourth embodiment. The printing of the first embodiment is completed until the filling is completed. ^ ^ Ϊ : When the key conducting body 4 is discharged, the plating via 4 is plated. The method is formed in the blind hole 11 and its thickness increases with time, f to fill the blind hole 11 and cover the second side [upper side] Layer 2, the protective cover 3 protects exposed in the blind bore of the portion not affected by Shushu. That is, the electrical

1303541

V. INSTRUCTION DESCRIPTION (6) The plating body 4 extends to the open end of the pupil and forms a projection. Referring to FIGS. 2 and 3H, the printing conductance of the first embodiment of the present invention is the fifth step of the hole conducting method: selecting the grinding method to level the electric ore body 4, that is, the electroplating conducting body 4 The projection 4 is flattened, and the polishing rod 11 is selected for mechanical, electrolytic or laser polishing, whereby the blind hole 11 conducts the conductive layer 2 on both sides of the edge layer 1 by means of 吱ίϊ ϋ4. As described above, the conductive layer 2 of the closed end of the blind hole 11 is used as an external plating 66 Ϊ Φ and the opening of the f hole 1 1 is appropriately covered by the 'shield 3' The household borrowing] f 2 β thereby ensures that the blind via U directly directs the electroplated conductor 4 from the inside out. Compared with the present invention, the step of forming the conductive layer for S can be omitted (for example, the first hole, the blind hole 11 forms a machine for the defective hole f f 510 ' and can have (4) the quality of the pass through, and the blind hole 11 is improved. The interlayer conduction method is as follows: Ϊ2: Α to 4E shows that the blind hole conduction method of the printing w plate of the second embodiment of the present invention comprises the steps of: brushing the conductive electrodes V2 and 2 at: the edge layer 1 - the first side & - the second side has - forming at least one blind via u;, the second side of the layer 1 extends through the conductive layer 2, to [2], in the insulating layer, the conductive layer 2, in the blind via 〗! A protective cover 3 is additionally provided on one side to cover the crucible, and the electroplating process is performed to make the electroconductive layer 2 on the side as an electrode, the body 4; in the beta blind hole 11 Depositing to form an electroplating conduction [4], when the electroplating guide and the conduction body 4 accumulate to fill the open end of the blind hole

C:\Logo-5\Five Continents\PK9781.ptd Page 13.1303541 5. After the invention description (7), the protective cover 3 covering the conductive layer 2 is removed, and [5], the blind hole 11 is utilized. The plating via 4 is electrically connected to the two sides of the edge layer 1 and 6 纟 conductive layers 2 and 2 ′′ and a top portion of the plating via 4 is formed with a bump 41 ′ for the soldering of the printed circuit board. Pad [pa] and input/output terminal [I/O]. Compared with the first embodiment, the fifth step of the second embodiment is deposited by appropriately increasing the deposition thickness of the electroplated via 4. The thickness of the plating cover 31 of the protective cover 3 is substantially equal to the thickness of the protective cover 3, so that the protruding height of the bump 4 1 of the plating conductive body 4 will be higher than the second conductive. The layer 2' can be used as a solder pad and an input/output terminal of the printed circuit board for connecting solder balls, pads or pins of other electronic products (such as packaged ICs), thereby simplifying the process of the conductive terminal. Referring to Figures 5A to 5D, the method for blind hole conduction of a printed circuit according to a third embodiment of the present invention comprises the steps of: 1] forming a conductive layer 2 on a first side of an insulating layer, and forming at least one blind via in a second side of the insulating layer; [2], in the first layer of the insulating layer a protective cover 3 ′ is additionally disposed on the side of the conductive layer 2 to cover the conductive layer 2 ; [3], the conductive layer 2 on the _ side of the insulating layer 1 is used as an electrode, and an electroplating process is performed, so as to Depositing a plating via 4 in the blind via; [4], after the plating via 4 is accumulated to fill the open end of the blind via 11, the protective cover 3 is removed; and '(5) The top of the plating via 4 forms a bismuth bump 41, and the bump 41

Page 14 C:\Logo-5\Five Continents\PK9781. ptd .1303541 V. Invention Description (8) "" 'Used as a soldering pad [pad] and input/output terminal for printed circuit boards [I /O 〕. Compared with the first and second embodiments, the third embodiment is applied to the field of a single-layer copper foil substrate. Thus, the second side [upper side] of the insulating layer 1 can omit the original "setting of the protective cover 3 [as shown in FIG. 3C. The step of covering the opening edge of the blind hole 11 = the outer region is shown. On the other hand, before the electroplating process is performed, the conductive layer 2 of the first side (lower side) preferably also covers another protective cover 3' or is selectively coated with a protective lacquer (not shown), thus preventing The first side [lower side] of the conductive layer 2 forms an excess electroplated deposit. φ Further, 'appropriate control increases the deposition thickness of the electroplated via 4, and the convex height of the bump 41 of the electrowinning conductor 4 will be higher than the plane of the second side of the insulating layer 1. Therefore, the bump 4 1 can be used as a conductive microsphere for printed circuit boards (such as solder balls for BGA packages), solder pads or input/output terminals for communication • solder balls, solder pastes or leads for electronic products (such as packaged ICs) The foot, in turn, achieves the purpose of the conductive terminal process. As described above, the blind via conduction method of the conventional printed circuit board first forms the via layer 12 in the hole wall of the blind via hole 11, and then the plating layer 22 is formed by plating to fill the blind via hole u. The hole 22 is easily formed inside the blind hole 11, thereby reducing the disadvantage of interlayer conduction quality. The invention of FIG. 2 is made of an electroconductive layer 2 using the closed end of the blind via 11 as an electrode of the electroplating process, and another conductive layer which appropriately shields the outer edge of the open end of the blind via 11 by the protective cover 3 Layer 2 '. Thereby, not only the blind hole 11 can be directly formed by internal and external key bond formation to form the electric clock conductor 4, but also the plating conduction body 4 can be selected to form a bump 41 as a pad or input/ Output terminal. therefore,

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1303541 V. INSTRUCTION DESCRIPTION (9) The present invention can effectively reduce the probability of the blind hole 11 forming a poor hole 2 2 , thereby improving the interlayer conduction quality of the blind hole 11 and simplifying the process of the conductive terminal. While the present invention has been described in detail with reference to the preferred embodiments of the present invention, it is not intended to limit the scope of the invention. The scope of the invention is defined by the scope of the appended claims. _ «

C:\Logo-5\Five Continents\PK9781.ptd Page 16 1303541 Schematic description of the drawing [Simple description of the drawing] Fig. 1: Schematic diagram of the blind hole conduction method of the conventional printed circuit board. Fig. 2 is a flow block diagram showing a blind via conduction method of a printed circuit board according to a first embodiment of the present invention. 3A and 3B are cross-sectional views showing the first step of the blind via conducting method of the printed circuit board according to the first embodiment of the present invention. Fig. 3C is a cross-sectional view showing the second step of the blind via conduction method of the printed circuit board of the first embodiment of the present invention. 3D and 3E are schematic cross-sectional views showing a third step of the blind via conduction P-channel method of the printed circuit board according to the first embodiment of the present invention. 3F and 3G are schematic cross-sectional views showing a fourth step of the blind via conduction method of the printed circuit board according to the first embodiment of the present invention. Fig. is a cross-sectional view showing the step of blind hole conduction of the printed circuit board of the first embodiment of the present invention. 4A, 4B, 4C, 4D and 4E are schematic cross-sectional views showing a blind via conducting method of a printed circuit board according to a second embodiment of the present invention. 5A, 5B, 5C and 5D are schematic cross-sectional views showing a blind via conducting method of a printed circuit board according to a third embodiment of the present invention. Main component symbol description] 12 conduction layer 21 plating layer 3' protective cover 1 insulating layer 11 blind hole 2 conductive layer 2' conductive layer 22 hole 3 protective cover

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Claims (1)

/ 1303541 VI. Patent application scope 1. A blind hole conducting method for a printed circuit board, comprising the steps of: having a first conductive layer on one side of one of the insulating layers, and another through a second side of the insulating layer Forming at least one blind hole, the blind hole is connected to the first conductive layer; a second conductive layer and a protective cover are further disposed on the second side of the insulating layer to cover the opening of the second conductive layer at the blind hole a region other than the edge (using the first conductive layer on the first side of the insulating layer as an electrode, and performing an electroplating process to deposit a plating via in the blind via: and _ when the electroplated via is accumulated to fill The protective cover is removed when the open end of the blind hole is completed. 2. The blind hole conducting method of the printed circuit board according to claim 1, wherein after removing the protective cover, the plating is removed by grinding The convex material of the conductive body is applied for the blind hole conduction mode of the printed circuit board according to item 2 of the special scope, wherein the grinding method can select laser, electrolysis or mechanical grinding. 4. Printing according to the first item of the patent application scope Circuit The blind via conduction method 'in the electroplating process, controlling the overflow thickness of the electroplated via to protrude from the conductive layer, so that the electroplated via forms a bump, and optionally as a pad, an input/output The blind via conducting method of the printed circuit board according to the invention of claim 2, wherein the second conductive layer on the second side of the insulating layer conducts the first side of the insulating layer via the conductive via of the blind via The first conductive layer. 6. The blind hole conduction side of the printed circuit board according to the item i of the patent application scope 1303541. The patent application scope method, wherein the protective cover is selected from a non-metal cover plate that can be repeatedly recycled, and the protective cover forms at least one key window corresponding to the blind hole to expose the second conductive layer in the blind hole. The part of the opening edge. 7. A blind via conducting method for a printed circuit board according to the first aspect of the patent application, wherein the protective cover is formed by photoresist coating. 8. A blind via conduction method for a printed circuit board according to the first aspect of the patent application, wherein the protective cover is formed by dry film pressing. 9. The method for conducting a blind via of a printed circuit board according to the scope of claim 1 of the patent application, wherein before the electric forging process, the first conductive layer on the first side of the insulating layer is selected to cover another protective cover to prevent the An electric ore deposit is formed outside the first conductive layer on the first side. 1 . The blind hole conducting method of the printed circuit board according to claim 9 , wherein before the electroplating process, the first conductive layer on the first side of the insulating layer is selected to be coated with a protective lacquer to prevent Electroplating deposition is formed outside the first conductive layer on the first side. 11. The blind hole conducting method of a printed circuit board according to claim 9, wherein before the electroplating process, the first conductive layer on the first side of the insulating layer further comprises a non-metal cover plate which can be repeatedly recycled. . 12. The blind via conduction method of a printed circuit board according to claim 9, wherein the first conductive layer on the first side of the insulating layer is selected to cover a protective cover before the electroplating process to prevent the Electroplated deposition is formed outside the first conductive layer on the first side. 1 . The blind hole conducting method of the printed circuit board according to claim 1 , wherein the insulating layer is selected from the group consisting of polyamidoamine, polyester, and poly(p-naphthalene). C:\Logo-5\Five Continents\PK9781.ptd Page 20 * 1303541 VI. Patent Application Scope 1 " Ethylene phthalate, liquid crystal polymer, Teflon. A blind hole conducting method for a printed circuit board, comprising the steps of: forming a conductive layer on a first side of an insulating layer, and forming at least one blind hole in a second side of the insulating layer, a blind via is connected to the conductive layer; a conductive layer on the first side of the insulating layer is used as an electrode, and an electroplating process is performed to deposit an electroplated via in the blind via and when the electroplated via is accumulated to fill When the open end of the blind via is completed, a top portion of the plating via is formed with a bump for selecting a pad and an input/output terminal of the 电路 _ PU, the blind hole conducting method of the printed circuit board according to claim 14, wherein before the electroplating process, the first side of the insulating layer is selected to cover a protective cover to prevent the first side Conductive layer '9 Lucheng electroplating deposition. a blind hole conducting method for a printed circuit board according to the scope of claim 5 of the patent application, wherein the protective cover is selected from the group of non-gold that can be recycled for recycling, and is described in item 5 of claim 5 A blind via conduction method for a printed circuit board, wherein the protective cover is formed by photoresist coating. 18. The blind hole conducting method of the printed circuit board according to claim 15 of the patent application, wherein the protective cover is formed by dry film pressing. W. The blind hole conducting method of the printed circuit board according to claim 15, wherein before the electroplating process, the guiding layer of the first side of the insulating layer is selectively coated with a protective lacquer to prevent the first side Outside the conductive layer ^ C:\Logo-5\Five C〇ntinents\PK9781. ptd Page 21 1303541 VI. Patent Application Scope into electric bond deposition. The blind hole conducting method of the printed circuit board according to claim 14 , wherein the insulating layer is selected from the group consisting of polyamidoamine, polyester, polyethylene naphthalate, liquid crystal polymer, Teflon. C:\Logo-5\Five Continents\PK9781. ptd Page 22