Circuit board Kebang
By thinning and filling the base layer, the adhesive layer is directly in contact with the base layer, and the problem of difficulty in measuring the binding force of PI and PP in the prior art is solved, and effective peel strength test of the binding force is achieved.
Patent Information
- Application Number
- CN202420969730.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-07
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-05-07
AI Technical Summary
The prior art is difficult to measure the binding force between PI and PP through standard physical quantities, and mainly relies on reliability tests such as reflow tests, which cannot effectively evaluate its peel strength.
By thinning the part of the base layer, a gap space is formed so that the adhesive layer can be directly in contact with the base layer, thereby conducting anti-peel strength testing. Specific methods include laser ablation of the base layer to thinnify and filling the gap with the fill layer to ensure full bonding of the adhesive layer to the base layer.
The peel strength test of the binding force of PI and PP is realized, providing a standard physical quantity to measure its binding force, thereby improving the reliability and accuracy of the test.
Smart Images
Figure CN222638773U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of PCB, in particular to a circuit board Kebang. Background Art
[0002] In printed circuit boards (PCBs), the bonding strength between copper foil and base layer (PI or hard board medium) or between copper foil and adhesive layer (PP) is usually evaluated by designing anti-peeling colbond. For multiple soft boards pressed together and rigid-flex boards, traditional anti-peeling colbond can evaluate the bonding strength between copper foil and PI, and the bonding strength between copper foil and PP can also be evaluated by pressing and etching a single copper foil. However, direct pressing of PI and PP is inevitable in PCB design.
[0003] In the related technology, the bonding strength between PI and PP can only be evaluated through reliability testing. The method adopted is to conduct a reflow test to observe whether there is blistering and delamination. However, there is no standard physical quantity (such as peel strength) to measure whether the bonding strength between PI and PP is qualified. Utility Model Content
[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a circuit board colbond, by thinning part of the base layer so that the adhesive layer can directly contact the base layer, so that the peel strength test of the bonding force between the adhesive layer and the base layer can be performed.
[0005] The circuit board Kobon according to the embodiment of the utility model comprises: an adhesive layer; two core boards, the two core boards are arranged on both sides of the adhesive layer, and at least one of the core boards comprises: a base layer, the base layer is at least partially thinned on both sides in the thickness direction to form a gap space; a filling layer, the filling layer is filled in the gap space.
[0006] According to the circuit board Kobon of the embodiment of the utility model, by thinning part of the base layer, the adhesive layer can be directly in contact with the base layer, so that the peel strength test of the bonding force between the adhesive layer and the base layer can be performed.
[0007] According to some embodiments of the present invention, the circuit board Colbond further comprises: a conductive connection layer, wherein the conductive connection layer is arranged at the end points of the base layer.
[0008] According to some embodiments of the present invention, the base layer includes: a thinning layer and a base layer, the thinning layer and the base layer are connected to each other, and the thickness of the thinning layer is less than the thickness of the base layer.
[0009] According to some embodiments of the present invention, the base layer further includes: a connecting layer, the connecting layer is connected between the thinning layer and the base layer, and the connecting layer is arc-shaped or oblique-line-shaped.
[0010] According to some embodiments of the present invention, the thickness of the thinning layer is d1, and the length of the thinning layer is h1, wherein d1 and h1 respectively satisfy the relationship: 3.0mm≤d1≤3.5mm, 45mm≤d1≤55mm.
[0011] According to some embodiments of the present invention, the thickness of the base layer is d2, and the length of the base layer is h2, wherein d2 and h2 respectively satisfy the relationship: 6.0mm≤d2≤6.5mm, 7.5mm≤h2≤8.5mm.
[0012] According to some embodiments of the present invention, the adhesive layer is a polypropylene layer.
[0013] According to some embodiments of the present invention, the base layer is a polyimide layer.
[0014] According to some embodiments of the present invention, the conductive connection layer is a copper layer.
[0015] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:
[0017] Figure 1 The structure of the circuit board according to the embodiment of the utility model is schematically shown in FIG. Figure 1 ;
[0018] Figure 2 This is a schematic diagram of the structure of the core plate according to an embodiment of the utility model. Figure 1 ;
[0019] Figure 3 This is a schematic diagram of the structure of the core plate according to an embodiment of the utility model. Figure 2 ;
[0020] Figure 4 This is a schematic diagram of the structure of the core plate according to an embodiment of the utility model. Figure 3 ;
[0021] Figure 5 The structure of the circuit board according to the embodiment of the utility model is schematically shown in FIG. Figure 2 .
[0022] Reference numerals:
[0023] 100. Circuit board Kebang;
[0024] 10. Adhesive layer;
[0025] 20, core board; 21, base layer; 211, thinning layer; 212, base layer; 213, connecting layer;
[0026] 30. Filling layer;
[0027] 40. Conductive connecting layer. DETAILED DESCRIPTION
[0028] The embodiments of the present utility model are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present utility model are described in detail below.
[0029] Reference below Figure 1-Figure 5 A circuit board Colback 100 according to an embodiment of the present invention is described.
[0030] In order to evaluate the durability and stability of the connection points on the circuit board when subjected to external stress, a peel strength test is required. The peel strength refers to the minimum force required to peel two parts per unit width. The circuit board Cobon 100 is a sample for peel strength testing. It can test the peel strength of the circuit board and usually has a fixed design standard on the edge of the circuit board.
[0031] And, the method for testing the peeling strength of the circuit board Cobon 100 is: lift one end of the circuit board Cobon 100 with a blade and fix it to the machine, apply tension through the machine, and the value displayed on the machine is the peeling strength of the circuit board.
[0032] Reference Figure 1-4 As shown, the circuit board Kobon 100 of the embodiment of the utility model comprises: an adhesive layer 10, two core boards 20 and a filling layer 30. The two core boards 20 are arranged on both sides of the adhesive layer 10, and at least one core board 20 comprises: a base layer 21, the base layer 21 is at least partially thinned on both sides in the thickness direction, and a gap space is formed, and the filling layer 30 is filled in the gap space.
[0033] The adhesive layer 10 is also called PP, also known as a prepreg, and can be bonded to the core board 20 on both sides. The core board 20 and the adhesive layer 10 can be pressed together to form a circuit board.
[0034] The core board 20 is composed of a multi-layer structure, including: a base layer 21, which is partially thinned on both sides in the thickness direction so that the adhesive layer 10 can directly contact the base layer 21, thereby being able to perform a peel strength test on the bonding force between the adhesive layer 10 and the base layer 21.
[0035] Reference Figure 3As shown, by laser ablation of the base layer 21, the core plate 20 is thinned on both sides in the thickness direction, and after ablation, it has the shape of a preliminary anti-peel strip. Laser ablation has very precise positioning capabilities, and the processing parameters can be determined according to factors such as the thickness of the base layer 21, the area, and the processing capacity.
[0036] At this time, since the base layer 21 of the core board 20 has gaps after ablation and cannot be directly pressed, it is necessary to use a filling layer 30 to fill the gaps after laser ablation to prevent the adhesive layer 10 from being connected to the side of the base layer 21 through high-temperature extrusion. In this way, after pressing, only the bottom surface of the base layer 21 is completely combined with the adhesive layer 10.
[0037] The filling layer 30 may be a peelable high-temperature adhesive tape, which can be easily peeled off after the ambient temperature drops.
[0038] Therefore, by thinning a portion of the base layer 21 , the adhesive layer 10 can be in direct contact with the base layer 21 , so that the peel strength test of the bonding force between the adhesive layer 10 and the base layer 21 can be performed.
[0039] Reference Figure 2-5 As shown, the circuit board Cobond 100 further includes: a conductive connection layer 40, which is arranged at the end of the base layer 21. The conductive connection layer 40 is located between the adhesive layer 10 and the base layer 21 to prevent the adhesive layer 10 from being too tightly bonded to the base layer 21, so that one end cannot be pulled out and fixed to the machine, which is inconvenient for testing.
[0040] Furthermore, the conductive connection layer 40 can also provide a clear path for electric current, so that electronic components can communicate and transmit signals with each other. The conductive layer can also be used as a channel for heat transmission and heat dissipation, and can effectively disperse and process the generated heat when necessary.
[0041] Reference Figure 3-5 As shown, the base layer 21 includes: a thinning layer 211 and a base layer 212. The thinning layer 211 and the base layer 212 are connected to each other, and the thickness of the thinning layer 211 is less than the thickness of the base layer 212. Specifically, the thinner portion of the base layer 21 after thinning is the thinning layer 211, and the portion that has not been thinned is the base layer 212. The thinning layer 211 is used to be fixed to a machine, and the machine applies a tensile force to the thinning layer 211 to test the peeling strength of the circuit board.
[0042] Reference Figure 3-5As shown, the base layer 21 further includes: a connecting layer 213, the connecting layer 213 is connected between the thinning layer 211 and the base layer 212, and the connecting layer 213 is in an arc shape or an oblique line shape. That is, the connecting layer 213 is a transition area between the thinning layer 211 and the base layer 212, and the connecting layer 213 is in an arc shape or an oblique line shape, which can minimize the heat accumulation at the same position during laser ablation of the base layer 21, reduce the risk of cracks and deformation of the base layer 21, and facilitate the size control of laser ablation.
[0043] Reference Figure 3 As shown, the thickness of the thinning layer 211 is d1, and the length of the thinning layer 211 is h1, wherein d1 and h1 respectively satisfy the relationship: 3.0mm≤d1≤3.5mm, 45mm≤d1≤55mm. That is, the thickness of the thinning layer 211 is not less than 3mm and not more than 3.5mm, and the length is not less than 45mm and not more than 55mm. The circuit board Cobon 100 within this range can adapt to the existing machine for testing peeling strength, and has good compatibility.
[0044] Reference Figure 3 As shown, the thickness of the base layer 212 is d2, and the length of the base layer 212 is h2, wherein d2 and h2 respectively satisfy the relationship: 6.0mm≤d2≤6.5mm, 7.5mm≤h2≤8.5mm. That is, the thickness of the base layer 212 is not less than 6mm and not more than 6.5mm, and the length is not less than 7.5mm and not more than 8.5mm. The circuit board Cobon 100 within this range can be adapted to the existing machine for testing the peeling strength, and has good compatibility.
[0045] The adhesive layer 10 is a polypropylene layer, which has high impact resistance and wear resistance, good chemical stability, and is not affected when etching other parts of the circuit board.
[0046] The base layer 21 is a polyimide layer. Polyimide has excellent high-temperature stability and can maintain its physical and chemical properties during high-temperature lamination. It also has good chemical stability and corrosion resistance and can resist erosion by many chemicals and solvents. It is not affected when etching other parts of the circuit board.
[0047] The conductive connection layer 40 is a copper layer. Copper has excellent conductivity. The high conductivity ensures low resistance and high efficiency of electrical signal transmission, reduces signal attenuation and energy loss, and has good mechanical strength and toughness. It can resist the influence of physical stress, high temperature and other environmental factors, can effectively disperse and process heat, ensure the stability and reliability of the circuit, and compared with other possible conductive materials, the cost of copper is relatively low and the economic benefits are better.
[0048] That is to say, compared with the traditional circuit board Cobon 100, the embodiment of the utility model etches the copper layer on the side in contact with the adhesive layer 10, so that the adhesive layer 10 can directly contact the base layer 21, thereby being able to perform a peel strength test on the bonding force between the adhesive layer 10 and the base layer 21.
[0049] Among them, circuit board etching usually uses chemical solutions to remove unnecessary areas on the copper layer to form conductive paths or other circuit structures.
[0050] In summary, the specific preparation process of the circuit board Cobon 100 is as follows: first, the copper layer on the side of the core board 20 away from the adhesive layer 10 is etched into a bare board, and then the copper layer on the side of the core board 20 close to the adhesive layer 10 is etched, and a part of the copper layer, that is, the conductive connection layer 40, is retained. In this way, the adhesive layer 10 can be in direct contact with the base layer 21 while leaving a gap to prevent the adhesive layer 10 from being too tightly bonded to the base layer 21, and one end cannot be pulled out and fixed to the machine, which is inconvenient for testing.
[0051] Then, refer to Figure 3 As shown, by laser ablation of the base layer 21, the core plate 20 is thinned on both sides in the thickness direction, and after ablation, it has the shape of a preliminary anti-peel strip. Laser ablation has very precise positioning capabilities, and the processing parameters can be determined according to factors such as the thickness of the base layer 21, the area, and the processing capacity.
[0052] At this time, since the base layer 21 of the core board 20 has gaps after ablation and cannot be directly pressed, it is necessary to use a filling layer 30 to fill the gaps after laser ablation to prevent the adhesive layer 10 from being connected to the side of the base layer 21 through high-temperature extrusion. In this way, after pressing, only the bottom surface of the base layer 21 is completely combined with the adhesive layer 10.
[0053] The filling layer 30 may be a peelable high-temperature adhesive tape, which can be easily peeled off after the ambient temperature drops.
[0054] Finally, use contour cutting to remove the entire circuit board's anti-peel Colbond, and then remove the high-temperature tape.
[0055] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.
[0057] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.
Claims
1. A circuit board, characterized in that: include: Adhesive layer; Two core plates, the two core plates are arranged on both sides of the adhesive layer, at least one of the core plates comprises: a base layer, the base layer is at least partially thinned on both sides in the thickness direction and forms a gap space; A filling layer is provided, wherein the filling layer fills the gap space.
2. The circuit board Colback according to claim 1, characterized in that: Also includes: A conductive connecting layer is arranged at an end point of the base layer.
3. The circuit board Colback according to claim 1, characterized in that: The base layer comprises: a thinning layer and a base layer, the thinning layer and the base layer are connected to each other, and the thickness of the thinning layer is smaller than the thickness of the base layer.
4. The circuit board Colback according to claim 3, characterized in that: The base layer further includes: a connection layer, the connection layer is connected between the thinning layer and the base layer, and the connection layer is in an arc shape or an oblique line shape.
5. The circuit board Colback according to claim 3, characterized in that: The thickness of the thinning layer is d1, and the length of the thinning layer is h1, wherein d1 and h1 respectively satisfy the relationship: 3.0mm≤d1≤3.5mm, 45mm≤d1≤55mm.
6. The circuit board Colback according to claim 3, characterized in that: The thickness of the base layer is d2, and the length of the base layer is h2, wherein d2 and h2 respectively satisfy the relationship: 6.0mm≤d2≤6.5mm, 7.5mm≤h2≤8.5mm.
7. The circuit board Colback according to claim 1, characterized in that: The adhesive layer is a polypropylene layer.
8. The circuit board Colback according to claim 1, characterized in that: The base layer is a polyimide layer.
9. The circuit board Colback according to claim 2, characterized in that: The conductive connection layer is a copper layer.