Blind slot processing technology of printed circuit board and printed circuit board

Abstract

The application discloses a blind slot processing technology of a printed circuit board and a printed circuit board manufactured by the blind slot processing technology of the printed circuit board, which comprises the following processing steps: step one, core plate pressing, inner layer core plate and outer layer core plate are pressed together, and a blocking glue material is filled into cavities of the outer layer core plate; step two, point into peelable glue, the blocking glue material in the cavities is taken out after pressing, a blind slot is formed, and the peelable glue is pointed into the blind slot to fill the blind slot; step three, drilling, a plug-in hole is drilled through the peelable glue at the blind slot of the inner layer core plate, and a through hole is drilled in the inner layer core plate and the outer layer core plate; step four, copper deposition, chemical copper deposition is carried out in the plug-in hole and the through hole; and step five, the peelable glue is taken out.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printed circuit board production, and particularly relates to a blind slot processing technology of a printed circuit board and the printed circuit board. BACKGROUND

[0002] With the rapid development of electronic communication equipment, the PCB (Printed Circuit Board) is developed in the direction of small size, light weight, three-dimensional installation and high connection reliability; the blind slot board in the PCB has a large demand, and the blind slot board is also developed in the direction of diversification and structural complexity.

[0003] In some blind slot boards, an insert hole is arranged in the blind slot, and in the existing process method, one method is as follows: the insert hole in the blind slot is first made in the inner layer core board in the form of a blind hole, the hole and the exposed part are pre-plated with gold and resist, the waste above the blind slot is pre-milled, the cavity is filled with an equal-height resist material during lamination of the core board, and the resist material is removed after lamination to realize the blind slot. However, this method does not protect the blind slot sidewall, the circuit and the hole wall during the whole process of outer layer metallization and electroplating, and only relies on the corrosion resistance of the inner layer pre-plated gold to retain the original circuit form after final etching. Because the exchange speed of the surface chemical solution and the exchange speed of the chemical solution in the slot are different, residual copper is easily generated in the slot, which causes short circuit or poor standing wave. SUMMARY

[0004] The present application aims to solve at least one of the problems in the prior art. To this end, the present application provides a blind slot processing technology of a printed circuit board, which can avoid the generation of residual copper in the blind slot.

[0005] The present application also provides a printed circuit board made by the blind slot processing technology of the printed circuit board.

[0006] According to the blind slot processing technology of the printed circuit board, the blind slot processing technology of the printed circuit board comprises the following processing steps:

[0007] Step one, core board lamination: the inner layer core board and the outer layer core board are laminated, and a resist material is used to fill the cavity of the outer layer core board;

[0008] Step two, point into peelable glue: the resist material in the cavity is removed after lamination to form a blind slot, and peelable glue is pointed into the blind slot to fill the blind slot;

[0009] Step three, drilling: an insert hole is drilled through the peelable glue at the blind slot of the inner layer core board, and a through hole is drilled in the inner layer core board and the outer layer core board;

[0010] Step four, copper plating, chemical copper plating is performed in the plug hole and the through hole;

[0011] Step five, taking out the peelable glue.

[0012] According to the blind slot processing technology of the printed circuit board, the inner layer core board does not need to be drilled with the plug hole in the blind slot, only the circuit pattern of the inner layer core board is made, the cavity is filled with the resistive glue material with the same height as the outer layer core board when the laminated board is pressed, the resistive glue material is taken out after pressing to form the blind slot, the peelable glue is then put into the blind slot, the through hole and the plug hole in the blind slot are drilled, the peelable glue is taken out after chemical copper plating. The process method can save costs: the inner layer core board does not need to be pre-plated with gold, the costs of gold salt and selective gold dry film materials can be saved, and the manufacturing costs of the inner layer dry film and gold plating are also saved; in addition, the hole position precision of the core board is higher: the plug hole in the blind slot and the outer layer through hole are drilled at one time, the hole position precision can meet the requirement of within ±0.10 mm, and is not affected by different materials, thicknesses, and pressing times; furthermore, there is no problem of residual copper corrosion: the blind slot sidewall, the circuit, and the hole wall are protected by the peelable glue during the chemical copper plating process, and subsequent whole board plating and pattern plating will not plate excess copper on the sidewall without metal, and there is no problem of residual copper corrosion.

[0013] According to some embodiments of the present application, before the step one, step six, inner light imaging, the inner layer pattern of the inner layer core board is transferred to the dry film on the surface of the core board to form a resist layer.

[0014] According to some embodiments of the present application, after the step five, step seven, outer light imaging, the outer layer circuit pattern of the laminated board after pressing is transferred to complete the outer layer pattern transfer and form the outer layer circuit.

[0015] According to some embodiments of the present application, after the step seven, step eight, pattern plating, the formed pattern layer, plug hole layer, and through hole layer after the outer light imaging of the outer layer circuit are plated.

[0016] According to some embodiments of the present application, after the step eight, step nine, film stripping and etching, the dry film on the circuit is washed away, and the non-circuit copper foil exposed by etching is etched.

[0017] The printed circuit board according to the second aspect of the embodiments of the present application is made by the blind slot processing technology of the printed circuit board according to any one of the first aspect of the embodiments.

[0018] The printed circuit board according to the embodiments of the present application has at least the following beneficial effects: the printed circuit board made by the blind slot processing technology of the printed circuit board according to the first aspect of the embodiments has no residual copper in the blind slot, and has high hole position precision, achieving higher product quality.

[0019] Additional aspects and advantages of the application will be apparent from the following description, which is given by way of example only, and with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 A schematic view of the inner core board of the present application;

[0022] Figure 2 A schematic view of the inner core board of the present application; Figure 1 A schematic view of the inner core board of the present application;

[0023] Figure 3 A schematic view of the inner core board of the present application; Figure 2 A schematic view of the inner core board of the present application;

[0024] Figure 4 A schematic view of the inner core board of the present application; Figure 3 A schematic view of the inner core board of the present application;

[0025] Figure 5 A schematic view of the inner core board of the present application; Figure 4 A schematic view of the inner core board of the present application;

[0026] Figure 6 A schematic view of the inner core board of the present application; Figure 5 A schematic view of the inner core board of the present application;

[0027] Figure 7 A schematic view of the inner core board of the present application; Figure 6 A schematic view of the inner core board of the present application;

[0028] Figure 8 A schematic view of the inner core board of the present application; Figure 7 A schematic view of the inner core board of the present application;

[0029] Figure 9 A schematic view of the inner core board of the present application; Figure 8 A schematic view of the inner core board of the present application;

[0030] Figure 10 A schematic view of the inner core board of the present application; Figure 9 A schematic view of the inner core board of the present application.

[0031] REFERENCE NUMERALS:

[0032] Inner core board 1; outer core board 2; resist material 3; strippable glue 4; plug-in hole 5; through-hole 6; copper layer 7; outer layer pattern 9; electroplating layer 10; blind groove 11. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described below in the detailed description and illustrated in the accompanying drawings by using examples, which are exemplary only and not intended to limit the present application. It should be understood that the embodiments described below are merely exemplary and are not intended to limit the present application.

[0034] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or position relationship shown in the drawings, only for the purpose of facilitating the description of the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0035] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is more than two. Greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If it is described as first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0036] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0037] The present application provides a blind slot 11 processing technology of a printed circuit board, which can avoid residual copper in the blind slot 11. The present application also provides a printed circuit board made by the above-mentioned blind slot 11 processing technology of a printed circuit board.

[0038] According to the first aspect of the present application, a blind slot 11 processing technology of a printed circuit board includes the following processing steps:

[0039] Referring to Figure 1 and Figure 2 , step one, core plate pressing, the inner layer core plate 1 and the outer layer core plate 2 are pressed together, and the blocking material 3 is filled into the cavity of the outer layer core plate 2. Specifically, the inner layer core plate 1 and the outer layer core plate 2 are pressed together through the semi-cured layer. As a cavity is provided in the outer layer core plate 2, the cavity is used to place the blocking material 3 with the same core plate thickness. The blocking material 3 can prevent the semi-cured layer material between the core plates from flowing into the cavity of the outer layer core plate 2 during the pressing process.

[0040] Referring to Figure 3 and Figure 4, step two, the cavity is filled with the peelable glue 4, and the resist material 3 is removed after the pressing, forming the blind slot 11, and the peelable glue 4 is filled into the blind slot 11; when the inner core board 1 and the outer core board 2 are pressed together, the resist material 3 is removed, and the original cavity forms the blind slot 11, and then the peelable glue 4 is filled.

[0041] Referring to Figure 5 , then step three, drilling, after filling the peelable glue 4 in the blind slot 11, the plug-in hole 5 is drilled in the inner core board 1 corresponding to the blind slot 11 of the inner core board 1; at the same time, the through hole 6 required by the process is drilled in the corresponding place of the inner core board 1 and the outer core board 2; then the next process is carried out.

[0042] Referring to Figure 6 , step four, copper plating, after drilling the required through hole 6 and the plug-in hole 5 in the blind slot 11, chemical copper plating is carried out in the plug-in hole 5 and the through hole 6, that is, a layer of copper layer 7 is plated on the surface of the two holes;

[0043] Referring to Figure 7 , the last step five, the peelable glue 4 material is removed, and the blind hole is finally formed.

[0044] As can be seen from the above embodiment, the inner core board 1 does not need to drill the plug-in hole 5 in the blind slot 11, only the circuit pattern of the inner core board 1 is made, the cavity is filled with the resist material 3 of the outer core board 2 when the laminated board is pressed, the resist material 3 is removed after pressing to form the blind slot 11, and the peelable glue 4 is filled in the blind slot 11, then the through hole 6 and the plug-in hole 5 in the blind slot 11 are drilled, and the peelable glue 4 is removed after chemical copper plating. This process can save cost: the inner core board 1 reduces the pre-plating gold process before pressing, which can save the cost of gold salt and selective gold dry film materials, and save the cost of inner layer dry film and gold plating manufacturing; in addition, the hole position precision of the core board is higher: since the plug-in hole 5 in the blind slot 11 of the inner core board 1 and the through hole 6 between the outer core board 2 and the inner core board 1 are drilled at the same time, the hole position precision between the two core boards can meet the requirement of within ±0.10mm, and is not affected by different materials, thickness, pressing times and shrinkage; moreover, there is no problem of incomplete etching of residual copper: the blind slot 11 side wall, circuit, hole wall can be protected by the peelable glue 4 material during chemical copper plating, that is, there is no copper layer 7 on the blind slot 11 side wall, circuit, hole wall, and subsequent plate plating and pattern plating will not deposit excess copper on the side wall without metal, avoiding the problem of incomplete corrosion of residual copper on the blind slot 11 side wall, circuit, hole wall, thereby avoiding the occurrence of short circuit or poor standing wave of the circuit board, and further improving the quality of the circuit board product.

[0045] Referring to Figure 1In some embodiments of the present application, before step one, step six is included, inner light imaging, transferring the inner layer pattern to the core board 1, transferring the circuit pattern to the dry film on the board surface to form the etching layer.

[0046] Referring to Figure 8 In some embodiments of the present application, after step five, step seven is included, outer light imaging, transferring the outer layer circuit pattern to the pressed board to complete the transfer of the outer layer pattern 9 and form the outer layer circuit.

[0047] Referring to Figure 9 In some embodiments of the present application, after step seven, step eight is included, pattern plating, plating the formed pattern layer, plug hole 5 layer and through hole 6 layer after the outer layer circuit outer light imaging, finally forming the plating layer 10 in the plug hole 5 and the through hole 6.

[0048] Referring to Figure 10 In some embodiments of the present application, after step eight, step nine is included, etching after removing the dry film on the circuit, etching the exposed non-circuit copper foil.

[0049] The printed circuit board according to the second aspect of the embodiments of the present application is made by the blind slot 11 processing technology of any one of the first aspect of the embodiments of the printed circuit board described above. The printed circuit board made by the blind slot 11 processing technology of any one of the first aspect of the embodiments of the printed circuit board described above has no residual copper in the blind slot 11, and has high hole position accuracy, achieving higher product quality.

[0050] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A blind slot processing technology for printed circuit boards, characterized in that, The processing steps include the following: Step 1, Core board lamination: The inner core board and the outer core board are laminated together, and the cavity of the outer core board is filled with a resist material; Step 2, Apply peelable adhesive: After pressing, remove the adhesive-resistant material from the cavity to form a blind groove, and apply peelable adhesive into the blind groove to fill it. Step 3, Drilling: Drill insertion holes through the peelable adhesive at the blind groove of the inner core board and drill through holes in the inner core board and the outer core board; Step 4, copper plating: chemical copper plating is performed on the plug-in holes and the through holes; Step 5: Remove the peelable adhesive.

2. The blind slot processing technology for a printed circuit board according to claim 1, characterized in that, Before step one, there is step six, internal light imaging, which transfers the inner layer pattern of the inner core board, transferring the circuit pattern onto the dry film on the core board surface to form a resist layer.

3. The blind slot processing technology for a printed circuit board according to claim 1, characterized in that, Following step five, step seven is included: external light imaging, which transfers the outer layer circuit pattern of the laminated board to complete the outer layer pattern transfer and form the outer layer circuit.

4. The blind slot processing technology for a printed circuit board according to claim 3, characterized in that, After step seven, step eight is included: pattern electroplating, in which the pattern layer, plug-in hole layer and through-hole layer formed after the outer circuit external light imaging are electroplated.

5. The blind slot processing technology for a printed circuit board according to claim 4, characterized in that, After step eight, step nine is included: film stripping and etching, which washes away the dry film on the circuit and etches the exposed non-circuit copper foil.

6. A printed circuit board, characterized in that, It is manufactured by the blind slot processing technology of a printed circuit board as described in any one of claims 1 to 5.

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