Glue-overflow-resistant high-performance multi-layer buried hole thick copper plate and processing technology thereof

Abstract

The invention relates to the technical field of thick copper plate processing equipment, in particular to an anti-glue-overflow high-performance multi-layer buried hole thick copper plate and a processing technology thereof, and the processing technology comprises the steps of cutting, inner layer circuit processing, browning, pressing, drilling, copper deposition, electroplating and drying. According to the invention, pre-pressing treatment is set, a prepreg adopts a PP adhesive layer with high adhesive content and high adhesive thickness, 108068% PP is adopted for adhesive filling, the adhesive filling amount and medium thickness requirements can be considered, balance copper is added in a blank position in a board, the residual copper rate of each layer is increased from 40% to 52%, the adhesive filling pressure is reduced, and the design of an exhaust strip is added in an inner copper sheet, so that the production cost is reduced. The inner-layer copper foil has 19 oz, and the thermal conductivity of copper causes the temperature rise to be too fast when the plate is heated, so that the compression time of the PP in a liquid state is prolonged, the glue overflowing capability of the PP is improved, the PP capable of being filled with the glue is reduced due to the glue overflowing of the PP, and the glue lacking in the pressing process is caused; glue filling can be improved by slowing down temperature rise or reducing compression time.

Description

Technical Field

[0001] The invention relates to the technical field of thick copper plate processing equipment, and in particular to an anti-glue overflow high-performance multi-layer buried hole thick copper plate and a processing technology thereof. Background Art

[0002] Multilayer thick copper plate is a printed circuit board with multiple layers of copper foil, and the copper thickness of each layer of copper foil is ≥2oz (ounce, 1oz means the average weight of copper foil on an area of ​​1 square foot is 28.35g, and the average thickness of copper foil is expressed by weight per unit area). Multilayer thick copper plate is widely used in electronic equipment, automobiles, application satellites, launch vehicles, manned spacecraft and exploration aircraft. Multilayer thick copper plate is processed by multilayer thick copper plate processing method.

[0003] At present, the processing flow of multi-layer thick copper plates includes: production of semi-finished products, production of multi-layer structures, cutting, punching and forming of thin plates, and surface treatment and testing.

[0004] However, the current board thickness control is not precise enough, which can easily lead to uneven board thickness and affect the accuracy of the product. In particular, the phenomenon of glue overflow is relatively common, resulting in reduced accuracy and yield of the finished board. In addition, there are disadvantages such as complex process and high cost. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a high-performance multi-layer buried hole thick copper plate with resistance to glue overflow and its processing technology, so as to solve the current technical problems that the thickness control of the board is not accurate enough, which easily leads to uneven board thickness and affects the precision of the product, especially the glue overflow phenomenon is relatively common, resulting in reduced precision of the finished board and reduced yield, and there are technical problems such as complex process and high cost.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A high-performance multi-layer buried hole thick copper plate with anti-overflow glue and a processing technology thereof, comprising: a first step, cutting: cutting the original copper clad plate to obtain a plurality of copper clad plates;

[0008] The second step is inner layer circuit processing: dry film, exposure: development, etching and film stripping, AO1 inspection;

[0009] The third step is browning: generating an oxide layer and performing pre-pressing treatment;

[0010] Step 4: Lamination: Prepreg, copper clad laminate, copper foil are stacked and heat dissipation components are added, and then pressed at high temperature;

[0011] Step 5: Drilling: opening through holes, blind holes and buried holes;

[0012] Copper deposition: forming a thin copper layer on the hole wall for circuit connection;

[0013] Electroplating: full board electroplating;

[0014] Step 6: Drying, post-processing and packaging.

[0015] Further, the cutting steps:

[0016] According to the required size and process requirements, the original copper clad laminate is cut using a shearing machine to obtain multiple copper clad laminates.

[0017] Further, the plurality of copper clad laminates are subjected to dry film processing in sequence;

[0018] The copper clad laminate after drying is exposed, developed, etched and film stripped;

[0019] Cleaning and drying the exposed copper clad laminate;

[0020] Carry out A01 test on the cleaned and dried copper clad laminate to determine whether it is qualified.

[0021] Furthermore, the thick copper plate after the inner layer circuit processing is placed in a browning liquid for chemical reaction to form a browning layer.

[0022] Further, pre-pressing treatment:

[0023] The semi-cured sheet adopts a PP adhesive layer with high adhesive content and high adhesive thickness, and uses 108068% PP for filling;

[0024] Add balance copper in the blank space of the board, and the residual copper rate of each layer increases from 40% to 52%;

[0025] Add exhaust strips to the inner copper layer so that air can be discharged during pressing;

[0026] Add heat dissipation mechanism to slow down the temperature rise.

[0027] Furthermore, before lamination, hot melt + rivet processing is used, and concentric circles are added between layers to judge the quality of inter-layer alignment. After hot melt, X-ray full concentric circles are first used to confirm that there is no offset before rivets are added, and then X-ray full concentric circles are used again to confirm that there is no abnormality before lamination.

[0028] Furthermore, during lamination: the copper foil, copper clad laminate and prepreg are stacked in sequence from outside to inside in a bidirectional manner, and multiple groups of copper foil, copper clad laminate and prepreg can be stacked and pressed at high temperature according to needs.

[0029] Furthermore, drilling: holes are opened on the copper clad board after the pressing is completed, and through holes, blind holes and buried holes are opened according to needs, and then copper plating is performed to cover the holes to make the circuit conductive, and the whole board is electroplated in the electroplating tank.

[0030] A high-performance multi-layer thick copper plate with buried holes and anti-glue overflow can be obtained by using any of the above-mentioned processing techniques for the high-performance multi-layer thick copper plate with buried holes and anti-glue overflow.

[0031] Beneficial effects of the present invention:

[0032] By setting up a pre-pressing treatment, the semi-cured sheet adopts a PP glue layer with a high glue content and high glue thickness, and uses 108068% PP for glue filling, which can take into account the requirements of glue filling amount and medium thickness, and increase the balance copper in the blank position of the board. The residual copper rate of each layer is increased from 40% to 52%, which reduces the pressure of glue filling. The exhaust strip design is added to the inner copper foil to ensure that the gas can be discharged during pressing, ensuring better glue filling of PP. The inner copper foil has 19oz. The thermal conductivity of copper causes the temperature to rise too quickly when the board is heated, thereby increasing the pressure time of PP in liquid state and increasing the overflow ability of PP. The overflow of PP will cause the PP that can be filled to decrease, thereby causing lack of glue in pressing; the filling can be improved by slowing down the temperature rise or reducing the pressure time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0034] Figure 1 The present invention is a schematic diagram of the process flow of an embodiment of the present invention of an anti-overflow glue high-performance multi-layer buried hole thick copper plate and its processing technology. DETAILED DESCRIPTION

[0035] The following will be combined with the attached embodiment of the present invention Figure 1 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0037] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0038] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] See also Figure 1 As shown, a high-performance multi-layer thick copper plate with anti-overflow glue and buried holes and a processing technology thereof include: the first step, cutting: cutting the original copper clad plate to obtain multiple copper clad plates;

[0040] The second step is inner layer circuit processing: dry film, exposure: development, etching and film stripping, AO1 inspection;

[0041] The third step is browning: generate an oxide layer and perform pre-pressing treatment. By setting up pre-pressing treatment, the semi-cured sheet uses a PP glue layer with high glue content and high glue thickness, and uses 108068% PP for filling, which can take into account the filling amount and medium thickness requirements. Balance copper is added to the blank position in the board. The residual copper rate of each layer is increased from 40% to 52%, which reduces the pressure of filling. The exhaust strip design is added to the inner copper foil to ensure that the gas can be discharged during pressing, ensuring better filling of PP. The inner copper foil has 19oz. The thermal conductivity of copper causes the temperature to rise too quickly when the board is heated, thereby increasing the pressure time of PP in liquid state, increasing the overflow capacity of PP, and the overflow of PP will cause the PP that can be filled to decrease, resulting in lack of glue during pressing; filling can be improved by slowing down the temperature rise or reducing the pressure time;

[0042] Step 4: Lamination: Prepreg, copper clad laminate, copper foil are stacked and heat dissipation components are added, and then pressed at high temperature;

[0043] Step 5: Drilling: opening through holes, blind holes and buried holes;

[0044] Copper deposition: forming a thin copper layer on the hole wall for circuit connection;

[0045] Electroplating: full board electroplating;

[0046] Step 6: Drying, post-processing and packaging.

[0047] Specifically, by optimizing the processing technology of multi-layer buried hole thick copper plates, the overflow phenomenon was effectively suppressed and the performance of the plates was significantly improved. By utilizing a number of technical means, from material selection to processing flow, the risk of PP glue overflow was reduced, ensuring a good glue filling rate and circuit connection performance of the board.

[0048] In this embodiment, the cutting steps are:

[0049] According to the required size and process requirements, the original copper clad laminate is cut using a shearing machine to obtain multiple copper clad laminates.

[0050] Specifically, during the cutting stage, the copper clad laminate is cut precisely according to requirements to provide an accurate benchmark for subsequent processing.

[0051] Performing dry film processing on a plurality of copper clad laminates in sequence;

[0052] The copper clad laminate after drying is exposed, developed, etched and film stripped;

[0053] Cleaning and drying the exposed copper clad laminate;

[0054] Carry out A01 test on the cleaned and dried copper clad laminate to determine whether it is qualified.

[0055] Specifically, the inner layer circuits are accurately prepared through processes such as dry film, exposure, development, etching and film stripping, and the circuit quality is guaranteed through AO1 testing.

[0056] The thick copper plate after the inner layer circuit processing is placed in the browning liquid for chemical reaction to form a browning layer.

[0057] Specifically, the browning process is mainly aimed at the pressing process, using a PP glue layer with a high glue content and high glue thickness, and by adding balancing copper and exhaust strip design to reduce the filling pressure, improve the effectiveness of gas discharge, and ultimately reduce the risk of PP glue overflow.

[0058] Before pressing, hot melt + rivet processing is used, and concentric circles are added between layers to judge the quality of inter-layer alignment. After hot melt, X-ray full concentric circles are first used to confirm that there is no offset before rivets are added, and then X-ray full concentric circles are used again to confirm that there is no abnormality before pressing.

[0059] Specifically, a two-way superposition combination method is adopted in the lamination stage, combined with hot melt + rivet processing, and the inter-layer alignment is detected by X-ray full-view concentric circles to ensure the accuracy of lamination. Hot melt + rivet method is used for lamination inter-layer alignment, which ensures that PP is evenly filled with glue during the lamination process and avoids the problem of overflowing glue.

[0060] During lamination: copper foil, copper clad laminate and prepreg are stacked from outside to inside in turn and in a bidirectional manner. Multiple groups of copper foil, copper clad laminate and prepreg can be stacked and pressed at high temperature according to needs.

[0061] Drilling: Drill holes on the copper-clad board after lamination. Open through holes, blind holes and buried holes as required, then perform copper plating to cover the holes for circuit connection, and perform full-board electroplating in the electroplating tank.

[0062] Specifically, through precise drilling, copper deposition and electroplating processes, circuit connection is completed to produce a high-performance anti-overflow glue multi-layer buried hole thick copper plate.

[0063] The technical solution also provides a high-performance multi-layer thick copper plate with buried holes and anti-glue overflow, which can be obtained by using any of the processing techniques for the high-performance multi-layer thick copper plate with buried holes and anti-glue overflow described above.

[0064] In summary, compared with the prior art, the processing technology of the anti-overflow high-performance multi-layer buried hole thick copper plate has at least the following beneficial effects: by providing a pre-pressing treatment, the semi-cured sheet adopts a PP glue layer with a high glue content and a high glue thickness, and 108068% PP is used for glue filling, which can take into account the glue filling amount and the medium thickness requirements, and increase the balance copper in the blank position of the board. The residual copper rate of each layer is increased from 40% to 52%, which reduces the pressure of glue filling, and adds a venting strip design in the inner copper foil to ensure that the gas can be discharged during pressing, so as to ensure better glue filling of PP. The inner copper foil has 19oz. The thermal conductivity of copper causes the temperature to rise too quickly when the board is heated, thereby increasing the pressure time of PP in liquid state, increasing the overflow ability of PP, and the overflow of PP will cause the PP that can be filled to be reduced, thereby causing lack of glue during pressing; the filling can be improved by slowing down the temperature rise or reducing the pressure time.

[0065] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A processing technology for a high-performance multi-layer buried hole thick copper plate with anti-overflow glue, characterized in that: include: The first step is cutting: cutting the original copper clad laminate to obtain multiple copper clad laminates; The second step is inner layer circuit processing: dry film, exposure: development, etching and film stripping, AO1 inspection; The third step is browning: generating an oxide layer and performing pre-pressing treatment; Step 4: Lamination: Prepreg, copper clad laminate, copper foil are stacked and heat dissipation components are added, and then pressed at high temperature; Step 5: Drilling: opening through holes, blind holes and buried holes; Copper deposition: forming a thin copper layer on the hole wall for circuit connection; Electroplating: full board electroplating; Step 6: Drying, post-processing and packaging.

2. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 1 is characterized in that: Cutting steps: According to the required size and process requirements, the original copper clad laminate is cut using a shearing machine to obtain multiple copper clad laminates.

3. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 2 is characterized in that: Performing dry film processing on a plurality of copper clad laminates in sequence; The copper clad laminate after drying is exposed, developed, etched and film stripped; Cleaning and drying the exposed copper clad laminate; Carry out A01 test on the cleaned and dried copper clad laminate to determine whether it is qualified.

4. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 3 is characterized in that: The thick copper plate after the inner layer circuit processing is placed in the browning liquid for chemical reaction to form a browning layer.

5. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 4 is characterized in that: Pre-treatment before lamination: The semi-cured sheet adopts a PP adhesive layer with high adhesive content and high adhesive thickness, and uses 108068% PP for filling; Add balance copper in the blank space of the board, and the residual copper rate of each layer increases from 40% to 52%; Add exhaust strips to the inner copper layer so that air can be discharged during pressing; Add heat dissipation mechanism to slow down the temperature rise.

6. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 1 is characterized in that: Before pressing, hot melt + rivet processing is used, and concentric circles are added between layers to judge the quality of inter-layer alignment. After hot melt, X-ray full concentric circles are first used to confirm that there is no offset before rivets are added, and then X-ray full concentric circles are used again to confirm that there is no abnormality before pressing.

7. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 1 is characterized in that: During lamination: copper foil, copper clad laminate and prepreg are stacked from outside to inside in turn and in a bidirectional manner. Multiple groups of copper foil, copper clad laminate and prepreg can be stacked and pressed at high temperature according to needs.

8. The processing technology of the high-performance multi-layer buried hole thick copper plate with anti-overflow glue according to claim 7 is characterized in that: Drilling: Drill holes on the copper-clad board after lamination. Open through holes, blind holes and buried holes as required, then perform copper plating to cover the holes for circuit connection, and perform full-board electroplating in the electroplating tank.

9. A high-performance multi-layer buried hole thick copper plate with anti-overflow glue, characterized in that: The processing technology of the anti-glue overflow high-performance multi-layer buried hole thick copper plate described in any one of claims 1 to 8 can be obtained.

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