Method for improving alignment degree of local mixed compression daughter board
By adding positioning holes and convex recesses in the installation area of the local mixed pressure panel, combined with the shrinkage value control, the problem of poor alignment between the local mixed pressure panel and the main board is solved, and higher alignment and lower layer bias risk is achieved.
Patent Information
- Application Number
- CN202411932142.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-04-11
AI Technical Summary
During the compression process between the local mixed combing coater and the motherboard, the daughterboard slide is prone to occur, resulting in poor alignment and poor functional performance of PCB short circuit.
The groove is fed at the installation area of the local mixed pressure coated plate, and the positioning holes are drilled on the sub-inner core plate and the local mixed pressure coated plate. Combined with the design of the projection and depression, the expansion and shrinkage values of the main board and the local mixed pressure coated plate are controlled so that they are consistent after pressing.
By adding the design of positioning holes and protruding depressions, we ensure the stable stress and close fit between the local mixed plate and the main plate when pressed, avoid alignment deviation, improve the alignment of the local mixed plate, and prevent layer deviation.
Smart Images
Figure CN119815728A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for improving the alignment of a local mixed-pressure sub-board, belonging to the technical field of circuit board manufacturing. Background Art
[0002] In the PCB (circuit board) process design, except for the necessary signal layer using high-frequency copper clad laminate to meet the signal transmission rate, other layers still use conventional FR-4 copper clad laminate (FR-4 is a flame-resistant material grade), which can effectively reduce the cost of raw materials and realize signal transmission in a fixed area. Such products are called mixed-pressure products, and the mixed-pressure has a local mixed-pressure process. Because it is a local inlaid high-frequency copper clad laminate, the local mixed-pressure sub-board is fixed in the board only by the flow of glue of the semi-cured sheet while the multi-layer board is pressed. It is easy to produce a sub-board slide, resulting in poor alignment and poor functionality of PCB short circuit. Summary of the invention
[0003] The object of the present invention is to provide a method for improving the alignment of a local mixed pressure sub-plate, so as to solve the problem of poor alignment in the prior art.
[0004] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions: The present invention provides a method for improving the alignment of a local mixed pressure sub-plate, comprising: The following operations are performed before the lamination stage in the process of making the circuit board: a groove is made at the preset local mixed pressure sub-board installation area on the secondary inner core board, the secondary inner core board is the secondary inner core board in the mixed pressure layer, three or more positioning holes are drilled in the overlapping area between the outer area of the circuit board and the area where the local mixed pressure sub-board is located, the overlapping area is located on the main board, and at least three positioning holes are not in a straight line, positioning holes of the same number, shape and position as those on the main board are drilled on the local mixed pressure sub-board, a protrusion is processed on the edge of the local mixed pressure sub-board, and a recessed part matching the protrusion is processed at a position on the main board corresponding to the protrusion; The following operations are performed when making the inner layer graphics during the circuit board production process: Control the expansion and contraction values of the main board and the local mixed-pressure sub-board, so that the expansion and contraction values of the main board and the local mixed-pressure sub-board remain consistent after pressing.
[0005] Furthermore, the positioning hole is a T-shaped structure.
[0006] Furthermore, the positioning hole is perpendicular to the local mixed pressure sub-board and the circuit board.
[0007] Furthermore, the number of the positioning holes is three.
[0008] Furthermore, the protrusion is a semicircular protrusion, the recess is a semicircular indentation, and the radius of the semicircular protrusion and the radius of the semicircular indentation are consistent.
[0009] Furthermore, the protrusions and the recesses are both provided in plurality, and the number of the protrusions and the number of the recesses are the same, and one protrusion matches one recess.
[0010] Furthermore, the controlling of the expansion and shrinkage value of the main board and the expansion and shrinkage value of the local mixed pressure sub-board includes: when the local mixed pressure sub-board performs the inner layer pattern exposure operation, adding a preventive expansion and shrinkage value so that the expansion and shrinkage value of the local mixed pressure sub-board is consistent with that of the main board after pressing.
[0011] Furthermore, the positioning hole at least penetrates to the last layer of the mainboard, but does not penetrate the entire mainboard.
[0012] Furthermore, the number of the protrusions is at least three.
[0013] Compared with the prior art, the beneficial effects achieved by the present invention are: The present invention provides a method for improving the alignment of a local mixed-pressure sub-plate, by adding a positioning hole design in the local mixed-pressure area, by cooperating with a protruding portion and a recessed portion, and by controlling the expansion and contraction value, so that the product has stable force and tight fit during pressing. After pressing, the main board and the local mixed-pressure sub-plate have the same expansion and contraction, avoiding alignment deviation caused by the lack of a force point during the pressing process. The three designs work together to improve the alignment of the local mixed-pressure sub-plate and avoid layer deviation between the local mixed-pressure sub-plate and the main board. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a flow chart of a method for improving the alignment of a local mixed pressure sub-plate provided by an embodiment of the present invention; Figure 2 It is a cross-sectional view of a local mixed pressure product in the prior art provided by an embodiment of the present invention; Figure 3 It is a plan view of a local mixed pressure product when a sliding plate phenomenon occurs without adding a positioning hole for fixing provided by an embodiment of the present invention; Figure 4 It is a cross-sectional view of a local mixed pressure product after adding positioning holes and fixing according to an embodiment of the present invention; Figure 5 It is a cross-sectional view of a local mixed pressure product after adding positioning hole fixation and snap-fit design provided by an embodiment of the present invention.
[0015] In the figure: 1. Partially mixed-pressure sub-board; 2. Resin; 3. Baseboard Core; 4. Positioning holes; 5. Main board; 6. Clips. DETAILED DESCRIPTION
[0016] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.
[0017] Example 1.
[0018] like Figure 1 As shown, the present invention provides a method for improving the alignment of a local mixed pressure sub-plate, comprising: The following operations are performed before the lamination stage in the process of making the circuit board: a groove is made at the preset local mixed pressure sub-board installation area on the secondary inner core board, the secondary inner core board is the secondary inner core board in the mixed pressure layer, three or more positioning holes are drilled in the overlapping area between the outer area of the circuit board and the area where the local mixed pressure sub-board is located, the overlapping area is located on the main board, and at least three positioning holes are not in a straight line, positioning holes of the same number, shape and position as those on the main board are drilled on the local mixed pressure sub-board, a protrusion is processed on the edge of the local mixed pressure sub-board, and a recessed part matching the protrusion is processed at a position on the main board corresponding to the protrusion; The following operations are performed when making the inner layer graphics during the circuit board production process: Control the expansion and contraction values of the main board and the local mixed-pressure sub-board, so that the expansion and contraction values of the main board and the local mixed-pressure sub-board remain consistent after pressing.
[0019] The present invention increases the design of positioning holes in the local mixed-pressure area, cooperates with the protruding parts and the recessed parts, and controls the expansion and contraction values, so that the product has stable force and tight fit during pressing. After pressing, the main board and the local mixed-pressure sub-board have the same expansion and contraction, avoiding alignment deviation caused by the lack of force points during the pressing process. The three designs work together to improve the alignment of the local mixed-pressure sub-board and avoid layer deviation between the local mixed-pressure sub-board and the main board.
[0020] Example 2.
[0021] like Figure 2 As shown, in the prior art, resin 2 is distributed between the substrate Core 3, and the partially mixed sub-plate 1 is pressed therein. Figure 3 As shown, the layer deviation between the local mixed pressure sub-board 1 and the main board 5 is relatively large.
[0022] The PCB production process is as follows: Board cutting (cutting the supplier's substrate into the expected size of the product), inner layer (etching out the inner layer circuits and graphics through coating, exposure, development, etching, and degumming), inner layer punching (punching out normal rivet holes outside the board), pressing and browning (removing dirt from the surface of the Core and roughening the surface copper layer, the Core is the core board), pressing and riveting (combining each Core together through rivets outside the board), pressing and stacking (stacking each layer of Core and adding buffering material), pressing (pressing the stacked boards together through high temperature and pressure), and subsequent processes.
[0023] The overall process after adding local mixed pressure includes: dividing the PCB into a local mixed pressure main board process and a local mixed pressure sub-board process.
[0024] Partial mixed pressure motherboard process: board cutting (cut the supplier's substrate into the expected size of the product), inner layer (etch out the inner layer circuits and graphics through coating, exposure, development, etching, and degumming), inner layer punching (punch out the normal rivet holes outside the board and the positioning holes added at the local mixed pressure position), inner layer fishing and forming (the layer passed by the local mixed pressure sub-board, the sub-board is fished out and placed in the corresponding shape), pressing and browning (remove dirt on the core surface and roughen the surface copper layer), pressing and riveting (combine each core together through the rivets outside the board), pressing and stacking (put the local mixed sub-board into the assembled motherboard, and insert the pins to ensure the alignment of the sub-board), pressing (pressing the stacked boards together through high temperature and pressure), and subsequent processes.
[0025] Partial mixed pressure daughter board process: board cutting (cut the supplier's substrate into the expected size of the product), inner layer (etch out the inner layer circuits and graphics through coating, exposure, development, etching, and degumming, and add expansion and shrinkage values), inner layer punching (punch out the normal rivet holes outside the board and the positioning holes added at the local mixed pressure position), inner layer fishing and forming (the local mixed pressure daughter board Core is fished out to obtain the corresponding shape and the buckles for auxiliary anti-slip), pressing and browning (remove dirt on the core surface and roughen the surface copper layer), pressing and stacking (put the local mixed daughter board into the assembled main board, and insert the pins to ensure the alignment of the daughter board), pressing (pressing the stacked boards together through high temperature and pressure), and inlaying them with the main board.
[0026] In order to solve the problem of poor alignment in the prior art, the present application adds three or more positioning holes in the area where the local mixing and pressure extends to the outside of the board, processes multiple clips for assisting access, controls the expansion and contraction values of the main board and the local mixing and pressure sub-board, and prevents the local mixing and pressure sub-board from sliding and offsetting and causing poor alignment.
[0027] The specific implementation of this application includes the following steps: Before the pressing stage in the circuit board production process, the following operations are performed: a CCD forming machine (automatic positioning punching and cutting forming machine) is used to make grooves at the preset local mixed pressure sub-board installation area on the sub-inner core board. The sub-inner core board is the sub-inner core board in the mixed pressure layer, and the other non-mixed pressure layers are not grooved. Three positioning holes are drilled in the overlapping area of the outer area of the circuit board and the area where the local mixed pressure sub-board is located (the positioning holes are punched out using a CCD punching machine, which is an automatic positioning punching and cutting punching machine). The positioning holes are nut structures (i.e., T-shaped structures), and the overlapping area The domain is located on the main board, and the three positioning holes are not in a straight line. Positioning holes of the same number, shape and position as those on the main board are drilled on the local mixed pressure sub-board, and each set of three positioning holes forms a triangular stable plane; three semicircular protrusions are processed on the edge of the local mixed pressure sub-board, and three semicircular concave parts matching the protrusions are processed at the positions corresponding to the protrusions on the main board. The positioning hole is combined with the buckle design (a protrusion and a concave part form a buckle), so that the sub-board can be closely embedded in the main board without sliding or offsetting; The following operations are performed when making the inner layer graphics during the circuit board production process: Control the expansion and contraction values of the main board and the local mixed-pressure sub-board, so that the expansion and contraction values of the main board and the local mixed-pressure sub-board remain consistent after pressing.
[0028] Carry out expansion and contraction value control to make the expansion and contraction value of the mainboard and the daughterboard consistent after pressing, so that the fixed daughterboard can avoid the slide plate and layer deviation, and effectively reduce the risk of separation of the local mixed pressure daughterboard and the mainboard slide plate at the local mixed pressure position.
[0029] The finished circuit board (partial mixed pressure product) is as follows Figure 4 and Figure 5 As shown; Figure 4 In the figure, the positioning hole 4 penetrates to the last layer of the main board, but does not penetrate the entire main board, and it can be seen that the positioning hole 4 penetrates from the local mixed pressure sub-board 1; Figure 5 It can be seen that the position of the positioning hole 4 is in the overlapping area of the circuit board's off-board area and the area where the local mixed pressure sub-board 1 is located, the position of the buckle 6 is at the edge of the local mixed pressure sub-board 1, and there is basically no offset between the local mixed pressure sub-board 1 and the main board 5.
[0030] The area outside the board is a non-client product area, and adding positioning holes here will not affect the appearance and functionality of the PCB.
[0031] When local mixed pressure extends to the area outside the board and only two positioning holes are drilled, it is easy for the pins to slide to one side under the force at the same time, causing uneven force and offset of the local mixed pressure sub-board. At this time, it is necessary to add one more pin hole (positioning hole) to form a triangular force to avoid this poor sliding. Therefore, at least three positioning holes must be opened. The specific number of holes to be opened depends on the area where the local mixed pressure extends to the outside of the board. The spacing between the positioning holes should not be too large or too small.
[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for improving the alignment of a local mixed pressure sub-plate, characterized in that: include: The following operations are performed before the lamination stage in the process of making the circuit board: a groove is made at the preset local mixed pressure sub-board installation area on the secondary inner core board, the secondary inner core board is the secondary inner core board in the mixed pressure layer, three or more positioning holes are drilled in the overlapping area between the outer area of the circuit board and the area where the local mixed pressure sub-board is located, the overlapping area is located on the main board, and at least three positioning holes are not in a straight line, positioning holes of the same number, shape and position as those on the main board are drilled on the local mixed pressure sub-board, a protrusion is processed on the edge of the local mixed pressure sub-board, and a recessed part matching the protrusion is processed at a position on the main board corresponding to the protrusion; The following operations are performed when making the inner layer graphics during the circuit board production process: Control the expansion and contraction values of the main board and the local mixed-pressure sub-board, so that the expansion and contraction values of the main board and the local mixed-pressure sub-board remain consistent after pressing.
2. The method for improving the alignment of a local mixed pressure sub-plate according to claim 1, characterized in that: The positioning hole is a T-shaped structure.
3. The method for improving the alignment of local mixed pressure sub-plates according to claim 1, characterized in that: The positioning hole is perpendicular to the local mixed pressure sub-board and the circuit board.
4. The method for improving the alignment of a local mixed pressure sub-plate according to claim 1, characterized in that: The number of the positioning holes is three.
5. The method for improving the alignment of local mixed pressure sub-plates according to claim 1, characterized in that: The protrusion is a semicircular protrusion, the recess is a semicircular indentation, and the radius of the semicircular protrusion and the radius of the semicircular indentation are consistent.
6. The method for improving the alignment of local mixed pressure sub-plates according to claim 1, characterized in that: There are a plurality of the protruding parts and a plurality of the recessed parts, and the number of the protruding parts and the number of the recessed parts are the same, and one protruding part matches one recessed part.
7. The method for improving the alignment of local mixed pressure sub-plates according to claim 1, characterized in that: The controlling of the expansion and shrinkage value of the main board and the expansion and shrinkage value of the local mixed pressure sub-board includes: when the local mixed pressure sub-board performs the inner layer pattern exposure operation, adding a preventive expansion and shrinkage value so that the expansion and shrinkage value of the local mixed pressure sub-board is consistent with that of the main board after pressing.
8. The method for improving the alignment of local mixed pressure sub-plates according to claim 1, characterized in that: The positioning hole at least penetrates to the last layer of the main board, but does not penetrate the entire main board.
9. The method for improving the alignment of local mixed pressure sub-plates according to claim 1, characterized in that: The number of the protrusions is at least three.