CN115696783A - Processing method for improving consistency of resistance values of heating strip circuit boards - Google Patents
Processing method for improving consistency of resistance values of heating strip circuit boards Download PDFInfo
- Publication number
- CN115696783A CN115696783A CN202211442726.1A CN202211442726A CN115696783A CN 115696783 A CN115696783 A CN 115696783A CN 202211442726 A CN202211442726 A CN 202211442726A CN 115696783 A CN115696783 A CN 115696783A
- Authority
- CN
- China
- Prior art keywords
- pcb
- circuit
- film
- plate
- processing method
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Manufacturing Of Printed Circuit Boards (AREA)
Abstract
The application relates to a processing method for improving consistency of resistance values of heating strip circuit boards, which comprises the following steps of S1: using a plate material with the copper thickness same as that of a finished product; s2, drilling a PCB; s3, copper deposition is carried out on the PCB; s4, circuit manufacturing A is carried out on the PCB; s5, plating holes on the PCB; s6, stripping the film of the PCB; s7, circuit manufacturing B is carried out on the PCB; s8, etching the PCB; s9, removing the film of the PCB; s10, performing resistance welding on the PCB plate; s11, carrying out surface treatment on the PCB plate to ensure good weldability or electrical property; the CB plate can meet the requirement of finished product copper thickness without surface copper electroplating, and by increasing a hole plating flow and canceling a full-plate electroplating flow and a pattern electroplating flow, the surface copper thickness difference caused by electroplating is eliminated, so that the resistance value of a circuit is only influenced by the width of the circuit, and the resistance value consistency of the product is improved.
Description
Technical Field
The invention relates to the technical field of circuit board processing and preparation, in particular to a processing method for improving the resistance consistency of a heating strip circuit board.
Background
The heating strip circuit board has excellent insulation strength, excellent voltage resistance, excellent heat conduction efficiency and excellent resistance stability, and is widely used for heating medical instruments and low-temperature baking equipment. One side of the heating strip circuit board product is distributed with dense wires and is connected with the other side of the large copper sheet circuit through a via hole, the product has strict requirements on the line width and the copper thickness, particularly the final resistance value, and the resistance value range is generally controlled within +/-15%.
The existing processing method of the heating strip circuit board comprises the following steps: cutting (using a plate material with the copper thickness being thinner than that of a finished product copper thickness) → drilling → copper deposition → full-plate electroplating → circuit (using a positive film for alignment) → pattern electroplating (electroplating thickening the whole circuit pattern required by a customer) → stripping → etching → tin stripping → solder resisting → surface treatment \8230 \\ 8230;.
The conventional positive film process is used for producing the products in the prior production and processing, the product has large resistance value deviation, poor resistance consistency and low yield.
Disclosure of Invention
Aiming at the defects, the invention provides the processing method for improving the resistance consistency of the heating strip circuit board, so that the resistance consistency of the sound product is improved, and the yield is improved.
The technical scheme adopted by the invention for solving the technical problem is to provide a processing method for improving the resistance consistency of a heating strip circuit board, which comprises the following steps:
s1, cutting: cutting the original copper-clad plate into PCB plates which can be manufactured on a production line by using plates with the copper thickness being the same as that of the finished product;
s2, drilling a PCB;
s3, copper deposition is carried out on the PCB;
s4, carrying out circuit manufacturing A on the PCB;
s5, plating holes on the PCB;
s6, stripping the film of the PCB;
s7, carrying out circuit manufacturing B on the PCB;
s8, etching the PCB;
s9, stripping the film of the PCB;
s10, performing resistance welding on the PCB plate;
s11, carrying out surface treatment on the PCB.
Further, in step S3, the thickness of the copper deposition layer is 0.4-0.8um.
Further, in step S4, the circuit manufacturing method a specifically includes steps of attaching a dry film, using a hole-plated film for alignment, exposing, and developing.
Further, in step S7, the circuit manufacturing B specifically includes the steps of dry film pasting, film alignment using a negative film, exposure, and development.
Further, in step S11, the surface treatment method is any one of a spray tin, an immersion gold, an OSP, an immersion tin, an immersion silver, a nickel-palladium gold, an electro-hard gold, and an electro-gold finger.
Further, after step S8 and before step S9, line inspection is required after etching, and it is determined whether there is a short-circuit defect or an open-circuit defect on the line, and if there is a short-circuit defect or an open-circuit defect, repair processing is required.
Further, the detection can be observed by naked eyes;
or, electrical measurement, using needle measurement or general electromechanical performance to check whether there is open circuit or short circuit;
or, carrying out optical AOI line scanning, firstly carrying out rapid shooting by using a high-definition image camera, then comparing the shot picture with an original file, and checking whether an open circuit or a short circuit exists.
Further, the short circuit repair comprises the following steps:
s01, determining a short-circuit position, and marking the short-circuit position on a production board;
s02, carrying out surface roughening treatment on the production plate;
s03, pasting a dry film on the surface of the production plate;
s04, placing the production plate with the film attached into an exposure machine and aligning by using a negative film;
s05, exposing the production plate;
s06, taking down the film;
s07, carrying out local shading treatment on the short circuit position on a cover film for producing a plate dry film;
s08, carrying out secondary exposure on the production plate;
s09, developing the production plate;
s010, carrying out local etching on the exposed outer short circuit position of the production plate;
s011, inspecting the production board;
if the quality is qualified, entering a subsequent production processing flow;
if not, the process returns to step S01.
Further, in step S01, the mark is required to be visible through the dry film after the dry film is attached.
Further, in step S07, the light shielding manner is to use a film pen to paint the short circuit position on the cover film of the dry film or use a light shielding tape to cover the short circuit position.
Furthermore, in the steps S4 and S7, the reliability of the electroplating through hole is ensured by controlling and adjusting by increasing the windowing of the plating hole film.
Compared with the prior art, the invention has the following beneficial effects: the PCB board can meet the requirement of finished product copper thickness without surface copper electroplating, and the thickness difference of the surface copper caused by electroplating is eliminated by increasing a hole plating process and canceling a whole board electroplating process and a pattern electroplating process, so that the resistance value of a circuit is only influenced by the width of the circuit, and the resistance value consistency of the product is improved.
Drawings
The invention is further described below with reference to the accompanying drawings.
FIG. 1 is a process flow diagram of example 1.
Fig. 2 is a flowchart of the short circuit rework process of example 2.
FIG. 3 is a schematic diagram of the structure of example 3 before it is exposed.
Fig. 4 is a schematic view of the structure of example 3 after exposure.
In the figure:
1-a board base layer; 2-a printed circuit layer; 3-a film layer; 301-exposed portions; 302-unexposed portions; 4-a light-shielding layer; 5-short circuit of line; and 6-marking.
Detailed Description
The preferred embodiments of the present invention are described in more detail below, however, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
Example 1:
the resistance value of the product is determined by the sum of the resistance of the line and the resistance of the via hole, and the resistance value of the line is influenced by the line length, the copper thickness of the line and the line width, wherein the line length is designed in a more demanding way and cannot be changed. Therefore, in the case of the design determination of the line length, improvement is required from other aspects so as to control the resistance value uniformity of the product and ensure the reliability of the product.
Embodiment 1 provides a processing method for improving the uniformity of resistance values of heating strip circuit boards.
As shown in fig. 1, the method comprises the following steps:
s1, cutting: and cutting the original copper-clad plate into a PCB plate which can be manufactured on a production line by using a plate with the copper thickness being the same as that of the finished product copper, so that the PCB plate can meet the requirement of the finished product copper thickness without surface copper electroplating.
S2, drilling a PCB; and drilling holes at the preset positions of the PCB to generate through holes among the layers of the circuit board, thereby achieving the purpose of communicating the layers.
S3, depositing copper on the PCB; the PCB after drilling is subjected to oxidation-reduction reaction in a copper deposition cylinder to form a copper layer so as to perform hole metallization on the holes, so that copper is deposited on the surface of the original insulated base material to achieve electric communication between layers;
in practical application, the thickness of the copper deposition layer is 0.4-0.8um.
S4, circuit manufacturing A is carried out on the PCB;
the specific steps of the circuit manufacturing A are sticking a dry film, using a plated hole film (a film with a window at a through hole) for alignment, exposing and developing.
In practical application, the reliability of the electroplated through hole is ensured by controlling and adjusting by increasing the windowing of the plated hole film.
And S5, plating holes on the PCB, wherein the plated holes only plate the through holes and the windowing areas of the through holes.
And S6, stripping the film of the PCB.
S7, carrying out circuit manufacturing B on the PCB;
the circuit manufacturing B comprises the specific steps of pasting a dry film, using a negative film (a negative film with a normal circuit pattern) for alignment, exposing and developing.
S8, etching the PCB plate; the circuit board is etched away with unwanted copper, leaving the desired portions.
And S9, stripping the film of the PCB. (ii) a
S10, performing resistance welding on the PCB plate;
solder resist, also called solder resist and green oil, is one of the most critical processes in the manufacture of printed boards, and is mainly characterized in that a layer of solder resist ink is coated on the board surface through screen printing or solder resist ink coating to prevent short circuit during welding. (ii) a
S11, carrying out surface treatment on the PCB plate to ensure good weldability or electrical property.
S13, carrying out surface treatment on the production plate;
in practical applications, the surface treatment method includes, but is not limited to, tin spraying, gold immersion, OSP, tin immersion, silver immersion, nickel-palladium-gold, electro-hard gold, and electro-gold finger.
In practical applications, after step S8 and before step S9, line inspection is performed after etching, and it is determined whether there is a short-circuit or open-circuit defect on the line, and if there is a short-circuit or open-circuit, repair processing is performed.
The detection can be observed by naked eyes;
or, electrical measurement, needle measurement or universal electromechanical performance check is carried out to determine whether an open circuit or a short circuit exists;
or, performing optical AOI line scanning, firstly performing rapid shooting by using a high-definition image camera, then comparing the shot image with an original file, and checking whether an open circuit or a short circuit exists.
The method eliminates the thickness difference of surface copper caused by electroplating by increasing the hole plating flow and canceling the whole plate electroplating and pattern electroplating flows, so that the resistance value of the circuit is only influenced by the width of the circuit, and the resistance value consistency of the products is improved.
Example 2:
when the etched circuit board has a short circuit which cannot be repaired manually, if the short circuits of different production boards occur at different positions, the circuit of the whole board can only be subjected to rework etching by using a negative film process, and the processing method can cause the circuit of the whole board to be thinner, thereby causing larger resistance value and larger impedance influence on the circuit.
Therefore, embodiment 2 provides a method for reworking a short circuit after etching on the basis of embodiment 1, which is suitable for the detection rework after step S8 in embodiment 1, and can perform local rework on short circuits at different positions to reduce the influence on the impedance value of the full board line.
As shown in fig. 2, the method comprises the steps of:
s01, determining a short circuit position, and marking the short circuit position on a production board, wherein the marked short circuit position is visible through a dry film after the dry film is attached;
in practical application, the marking mode is to mark a coordinate arrow on the production board process edge by using an oil pen so as to facilitate subsequent positioning.
S02, carrying out surface roughening treatment on the production plate to increase the roughness of a copper surface;
in practical application, the surface rough treatment is a grinding plate, mainly solves the problems of surface cleanliness and surface roughness, removes oxidation, increases the roughness of a copper surface and facilitates the attachment of a film on the copper surface;
preferably, the surface of the production plate is treated by microetching, and the marks of the short circuit positions are prevented from being removed.
And S03, a dry film is pasted on the surface of the production board, a layer of blue dry film is pressed on the pressed circuit board, and the dry film is a carrier.
S04, placing the production board with the film pasted in an exposure machine and aligning by using a negative film;
the negative film is designed according to the design line, and the short circuit position is substantially extra copper which is not in the design line and exceeds the redundant processing of the design line.
S05, exposing the production plate;
the dry film fully exposes the part of the circuit film with the designed circuit (the part with the designed circuit is transparent, the part without the designed circuit is lightproof, and the short circuit position does not belong to the designed circuit) under the energy of the lamp tube of the exposure machine; after exposure, the circuit is transferred to the dry film, and the dry film is exposed at the designed circuit position and not exposed at the designed circuit position (including the short circuit position).
And S06, taking down the film.
S07, carrying out local shading treatment on a short circuit position on a cover film for producing a dry film of the board;
in practical application, the light shielding mode is to use a film pen to paint the short circuit position on the cover film of the dry film or use a light shielding adhesive tape to cover the short circuit position.
S08, carrying out secondary exposure on the production plate;
after exposure, the dry film is exposed at a place where the light shielding treatment is not performed, and the dry film is not exposed at a place where the light shielding treatment is performed (i.e., a short-circuit position).
S09, developing the production board, wherein only the short circuit part is exposed after development, and the rest positions on the production board are covered by a corrosion resistant layer (the corrosion resistant layer is a dry film after sensitization);
the unexposed portions are developed away with a developer solution in a developer that is non-reactive to the exposed portions.
S010, local etching is carried out on the exposed short circuit position of the production board, so that etching of circuits on other positions on the production board is avoided, and the influence on the width and the impedance value of the circuit of the production board is reduced.
S011, inspecting the production board;
if the quality is qualified, entering a subsequent production processing flow;
if not, the process returns to step S01.
In practical application, the detection can be observed by naked eyes;
or, electrical measurement, using needle measurement or general electromechanical performance to check whether there is open circuit or short circuit;
or, performing optical AOI line scanning, firstly performing rapid shooting by using a high-definition image camera, then comparing the shot image with an original file, and checking whether an open circuit or a short circuit exists.
The method can perform local reworking on short circuits at different positions, and reduces the influence on the impedance value of the whole board line.
When the method is used for processing short circuit batch production plates with different positions, only the short circuit part is exposed after development, the rest positions on the production plate are covered by the anti-corrosion layer (the anti-corrosion layer is a dry film after sensitization), the short circuit part can be etched, the etching of circuits at the rest positions on the production plate is avoided, and therefore the influence on the circuit width and the impedance value of the production plate is reduced.
Example 3:
As shown in fig. 3, the post-etching short circuit rework preprocessing structure includes a board base layer 1, a printed circuit layer 2, a film layer 3, and a light shielding layer 4, which are sequentially disposed;
the film layer comprises an exposed part 301 covering the circuit area and an unexposed part 302 covering the non-circuit area, and the short circuit position is positioned in the unexposed part;
the board base layer is provided with a mark 6 convenient to search at the short circuit position 5 of the circuit, and the mark can be seen by naked eyes through the film layer;
the shading layer covers the film layer and covers the short circuit position of the circuit.
When the structure is used, the board with the structure is exposed, as shown in fig. 4, the exposed short circuit positions except the short circuit position covered by the light shielding layer are exposed, and only the short circuit position is exposed after the development treatment, the short circuit position can be locally etched, so that the etching of the circuits at the other positions on the production board is avoided, and the influence on the line width and the impedance value of the production board is reduced.
The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items and, therefore, once an item is defined, further discussion thereof is not required later.
In the description of the present application, it is to be understood that the directions or positional relationships indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the directions or positional relationships shown, and are for convenience in describing the present application and to simplify the description, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.
For convenience of description, spatially relative terms such as "over 8230; \8230above", "over 8230; \8230;, \8230above", "over 8230; \8230; upper surface", "above", etc., may be used herein to describe the spatial positional relationship of features. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted.
It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, so that the scope of the present application is not to be construed as being limited.
If the present application discloses or relates to parts or structures that are fixedly connected to each other, the fixedly connected connection can be understood as, unless otherwise stated: a detachable fixed connection (for example using a bolt or screw connection) can also be understood as: non-detachable fixed connections (e.g. riveting, welding), but of course, fixed connections to each other may also be replaced by one-piece structures (e.g. manufactured integrally using a casting process) (unless it is obviously impossible to use an integral forming process).
The above-mentioned preferred embodiments, object, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned preferred embodiments are only illustrative of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A processing method for improving the consistency of resistance values of heating strip circuit boards is characterized by comprising the following steps:
s1, cutting: cutting the original copper-clad plate into PCB plates which can be manufactured on a production line by using plates with the copper thickness being the same as that of the finished product;
s2, drilling a PCB;
s3, copper deposition is carried out on the PCB;
s4, circuit manufacturing A is carried out on the PCB;
s5, plating holes on the PCB;
s6, stripping the film of the PCB;
s7, circuit manufacturing B is carried out on the PCB;
s8, etching the PCB;
s9, removing the film of the PCB;
s10, performing resistance welding on the PCB plate;
s11, carrying out surface treatment on the PCB.
2. The processing method for improving the resistance consistency of the heating strip circuit board according to claim 1, characterized in that: in step S3, the thickness of the copper deposition layer is 0.4-0.8um.
3. A processing method for improving the resistance uniformity of a heating strip circuit board according to claim 1, wherein: in step S4, the circuit manufacturing A specifically comprises the steps of pasting a dry film, using a plated hole film for alignment, exposing and developing.
4. The processing method for improving the resistance consistency of the heating strip circuit board according to claim 1, characterized in that: in step S7, the circuit manufacturing B specifically comprises the steps of dry film pasting, film alignment by using a negative film, exposure and development.
5. A processing method for improving the resistance uniformity of a heating strip circuit board according to claim 1, wherein: in step S11, the surface treatment method is any one of tin spraying, gold immersion, OSP, tin immersion, silver immersion, nickel-palladium-gold, electro-hard gold, and electro-gold finger.
6. A processing method for improving the resistance uniformity of a heating strip circuit board according to claim 1, wherein: after step S8 and before step S9, line inspection is performed after etching, and it is determined whether there is a short-circuit or open-circuit defect on the line, and if there is a short-circuit or open-circuit, repair processing is performed.
7. The processing method for improving the resistance consistency of the heating strip circuit board according to claim 6, characterized in that:
the detection can be observed by naked eyes;
or, electrical measurement, using needle measurement or general electromechanical performance to check whether there is open circuit or short circuit;
or, carrying out optical AOI line scanning, firstly carrying out rapid shooting by using a high-definition image camera, then comparing the shot picture with an original file, and checking whether an open circuit or a short circuit exists.
8. The processing method for improving the resistance consistency of the heating strip circuit board according to claim 6, characterized in that: the short circuit repair comprises the following steps:
s01, determining a short-circuit position, and marking the short-circuit position on a production board;
s02, carrying out surface roughening treatment on the production plate;
s03, pasting a dry film on the surface of the production plate;
s04, placing the production plate with the film attached into an exposure machine and aligning by using a negative film;
s05, exposing the production plate;
s06, taking down the film;
s07, carrying out local shading treatment on the short circuit position on a cover film for producing a plate dry film;
s08, carrying out secondary exposure on the production plate;
s09, developing the production plate;
s010, locally etching the exposed outer short circuit position of the production plate;
s011, inspecting the production board;
if the quality is qualified, entering a subsequent production processing flow;
if not, the process returns to step S01.
9. The method of rework of post-etch short circuit with little impact on PCB line impedance values of claim 8, wherein: in step S01, the mark is required to be visible through the dry film after the dry film is attached.
10. The method of rework of post-etch short circuit with little impact on PCB line impedance values of claim 8, wherein: in step S07, the light shielding manner is to use a film pen to paint the short circuit position on the cover film of the dry film or to use a light shielding tape to cover the short circuit position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211442726.1A CN115696783A (en) | 2022-11-18 | 2022-11-18 | Processing method for improving consistency of resistance values of heating strip circuit boards |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211442726.1A CN115696783A (en) | 2022-11-18 | 2022-11-18 | Processing method for improving consistency of resistance values of heating strip circuit boards |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115696783A true CN115696783A (en) | 2023-02-03 |
Family
ID=85054648
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211442726.1A Pending CN115696783A (en) | 2022-11-18 | 2022-11-18 | Processing method for improving consistency of resistance values of heating strip circuit boards |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115696783A (en) |
-
2022
- 2022-11-18 CN CN202211442726.1A patent/CN115696783A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1108306A (en) | Process for manufacturing printed circuit boards | |
| CN108617104B (en) | Method for manufacturing printed circuit board with thickened copper local pattern | |
| CA2067710A1 (en) | Process for manufacturing printed circuits employing selective provision of solderable coating | |
| WO1994008443A1 (en) | Method and apparatus for fabricating printed circuit boards | |
| CN105814242A (en) | Treated surface copper foil, copper-clad laminate, printed wiring board, electronic device, and printed wiring board manufacturing method | |
| CN113891557B (en) | Printed circuit board manufacturing method | |
| CN111770638A (en) | Manufacturing process of printed circuit board with steps and printed circuit board | |
| CN113597113A (en) | Manufacturing method of high-reflectivity white oil circuit board | |
| CN110839319A (en) | Method for manufacturing high-precision impedance circuit | |
| CN111212528A (en) | Method for manufacturing multilayer printed circuit board | |
| CN111182738B (en) | Method for manufacturing characters on large copper surface of PCB | |
| CN112654155A (en) | Laser-fired lead windowing method and substrate preparation method | |
| KR20120007909A (en) | Printed wiring board manufacturing method | |
| CN110572952A (en) | Film covering method of ultrathin 5G copper-clad plate and preparation method of copper-clad plate | |
| CN114173478A (en) | Circuit board manufacturing method and circuit board | |
| CN114040598A (en) | Method for removing flash of metalized half hole of electric gold plate | |
| CN112261787B (en) | Drilling method for large-size printed board | |
| CN113225921A (en) | Method for manufacturing PCB blind hole | |
| CN115696783A (en) | Processing method for improving consistency of resistance values of heating strip circuit boards | |
| CN109287078B (en) | Manufacturing method of iron substrate circuit board, iron substrate circuit board and light source assembly | |
| CN117255500A (en) | PCB manufacturing method with golden finger and PCB | |
| CN111970839A (en) | Processing technology of printed circuit board capable of effectively saving electrogilding cost | |
| CN109496080B (en) | Circuit board electroplating process method | |
| JP2021111710A (en) | Flexible printed wiring board and manufacturing method thereof | |
| CN114630488A (en) | PCB conductor area mimeograph structure, PCB and preparation method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |