Vertical gantry type electroplating floating frame

Abstract

The utility model discloses a vertical gantry type electroplating floating frame. Comprising two end plates arranged oppositely, a bottom plate connected with the two end plates, side plates distributed on the two sides of the bottom plate and provided with a plurality of first through holes, a plurality of connecting blocks used for connecting the side plates and the bottom plate, clamping grooves formed in the two ends of the outer sides of the side plates, and baffles inserted into the clamping grooves and capable of sliding up and down. The connecting blocks on the two sides of the bottom plate are symmetrically arranged and are in a V shape, the bottom of the circuit board abuts against the connecting blocks, and the baffle is provided with a plurality of second through holes. According to the vertical gantry type electroplating floating frame provided by the utility model, the baffles capable of sliding up and down are additionally arranged on the outer sides of the side plates of the floating frame, so that the distribution of current lines can be adjusted, and the copper plating uniformity is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of printed circuit board production, in particular to a vertical gantry type electroplating floating frame. Background Art

[0002] During the printed circuit board (PCB) manufacturing process, plating uniformity is a key indicator of coating quality. For production, this coating uniformity directly impacts the subsequent fabrication and formation of fine circuitry. With the increasing demand for high-density PCBs, the requirements for uniform copper plating thickness are bound to become increasingly stringent, making the improvement and enhancement of plating uniformity a pressing issue.

[0003] Traditional vertical gantry electroplating systems feature a V-shaped bottom groove with circular holes along the sides. During the electroplating process, after the board is inserted into the float, the solution circulates through the holes, ensuring that the plated copper thickness is as uniform as possible at the pinch point. However, the actual electroplating process suffers from inherent flaws in copper thickness uniformity due to the edge effect of the current flowing through the board. During gantry electroplating, copper thickness can vary significantly (measurements show that the copper thickness at the pinch point of a 25µm copper plating process is 8-10µm thicker than at non-pinch points). This can easily lead to incomplete etching of the negative film or film lamination of the positive film during etching, resulting in scrapped PCBs.

[0004] Therefore, it is necessary to provide a new floating frame structure to improve copper plating uniformity to solve the above technical problems. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a vertical gantry electroplating floating frame, in which a baffle design which can slide up and down is added to the outer side of the side plate of the floating frame, so as to adjust the current line distribution and improve the copper plating uniformity.

[0006] The technical solution of the utility model is as follows:

[0007] A vertical gantry-type electroplating floating frame includes two end plates arranged opposite to each other, a bottom plate connecting the two end plates, side plates distributed on both sides of the bottom plate and having a plurality of first through holes, a plurality of connecting blocks for connecting the side plates and the bottom plate, slots provided at both ends of the outer sides of the side plates, and a baffle inserted into the slot and capable of sliding up and down. The connecting blocks on both sides of the bottom plate are symmetrically arranged and V-shaped, the bottom of the circuit board abuts against the connecting blocks, and the baffle is provided with a plurality of second through holes.

[0008] Furthermore, the second through holes distributed on the baffle are sparser than the first through holes distributed on the side plate.

[0009] Furthermore, the opening amount of the first through holes is 9-10 per square centimeter, and the opening amount of the second through holes is 5-7 per square centimeter.

[0010] Furthermore, the aperture of the second through hole is smaller than the aperture of the first through hole.

[0011] Furthermore, the aperture of the first through hole is 20-25 mm, and the second through hole can be divided into large hole, medium hole and small hole according to the aperture size, wherein the aperture of the large hole is 8-10 mm smaller than the aperture of the first through hole, the aperture of the medium hole is 11-12 mm smaller than the aperture of the first through hole, and the aperture of the small hole is 13-14 mm smaller than the aperture of the first through hole.

[0012] Furthermore, in the second through holes, the large holes, the middle holes and the small holes are arranged in sequence from top to bottom.

[0013] Furthermore, the side panels have a height of 25-30 mm and a thickness of 3-4 mm; the baffles have a height of 25-30 mm and a thickness of 3-4 mm.

[0014] Furthermore, the slot and the side plate are fixed by welding.

[0015] Compared with the prior art, the vertical gantry electroplating floating frame provided by the present invention has the following beneficial effects:

[0016] The utility model provides a vertical gantry-type electroplating floating frame with an additional baffle that can slide up and down on the outer side of the side panel. By adjusting the baffle's up and down sliding, the current line distribution can be adjusted. When the copper thickness at the clamping point of the circuit board is too thick, the baffle can be moved up to block some of the power lines, thereby reducing the copper thickness at the clamping point. Through holes are provided on the baffle for the convection of the chemical solution. When the baffle is adjusted in the vertical direction, the chemical solution can convect normally and will not completely block the distribution of the power lines. Therefore, the copper plating thickness only needs to be fine-tuned to reduce the extreme difference in copper thickness between the clamping point and the non-clamping point, thereby improving the uniformity of copper plating. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a structural diagram of the vertical gantry electroplating floating frame of the utility model;

[0019] Figure 2 yes Figure 1 The schematic diagram of the structure of the side plate of the vertical gantry electroplating floating frame shown;

[0020] Figure 3 yes Figure 1The schematic diagram of the structure of the baffle in the vertical gantry electroplating floating rack shown;

[0021] Figure 4 This is the distribution diagram of electric lines during the electroplating process. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the specific implementation methods of the present invention are further described below.

[0023] It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] See also Figure 1 , is a schematic diagram of the structure of a vertical gantry-type electroplating floating frame according to the present invention. The vertical gantry-type electroplating floating frame according to the present invention comprises two opposing end plates 1, a base plate 2 connecting the two end plates, side plates 3 distributed on either side of the base plate 2, a plurality of connecting blocks 4 for connecting the side plates 3 to the base plate 2, and connecting plates 5 for connecting the connecting blocks. The connecting blocks 4 on either side of the base plate are symmetrically arranged and V-shaped. The bottom of the circuit board abuts against the connecting blocks 4. The height of the connecting plates 5 is lower than that of the side plates 3. The connecting plates 5 not only strengthen the stability of the connecting blocks 4 but also allow current to flow through the bottom.

[0025] See also Figure 2 ,yes Figure 1 The following is a schematic diagram of the structure of the side panels in a vertical gantry-type electroplating floating frame. In this utility model, the side panels 3 are made of PVC material, with a height of 25-30 mm and a thickness of 3-4 mm. Several first through holes 31 are provided on the side panels 3, which serve as convection holes for the chemical solution. In this embodiment, the diameter of the first through holes 31 is 20-25 mm, and the number of openings is 9-10 per square centimeter.

[0026] The uniformity of copper plating thickness in electroplating lines has long been a major challenge for the circuit board industry. Two key factors influencing copper thickness uniformity are convection and distribution of electrical lines. After the circuit board is inserted into the float frame, poor convection and exchange of the plating solution at the bottom of the float frame, as well as obstruction of electrical lines, affect the copper on the circuit board. Ultimately, the copper thickness is higher at the pinch point (high current area) and lower at the opposite side (low current area).

[0027] Therefore, the present invention adjusts the distribution of current lines by adding a baffle that can slide up and down on the outside of the side panel. By adjusting the baffle to move up and down, if it is found that the copper thickness at the clamping point is too thick, the baffle is adjusted upward to block a part of the power lines, so that the copper plating thickness will be correspondingly thinned. Specifically, a card slot 6 is set at both ends of the outside of the side panel 3, and a baffle 7 is inserted into the card slot and can slide up and down. The card slot 6 can be made of PVC material and fixed to the side panel by welding. A sealing strip (not shown) is installed in the card slot 6, and the baffle 7 is inserted into the sealing strip. On the one hand, the sealing strip has elasticity and can clamp the baffle so that it does not slip in the absence of external force; on the other hand, the sealing strip and the baffle do not have a fixed constraint relationship. When an external force is applied upward or downward to the baffle, the baffle can slide up and down.

[0028] See also Figure 3 ,yes Figure 1 The schematic diagram of the structure of the baffle in the vertical gantry electroplating floating frame is shown. In this embodiment, the baffle 7 is made of PVC material, has a height of 25-30 mm, and a thickness of 3-4 mm. A plurality of second through holes 71 are provided on the baffle 7. The second through holes 71 serve as convection holes. When the baffle moves up and down, the chemical solution can circulate normally without completely blocking the distribution of electric force lines, allowing the copper plating thickness to be fine-tuned to improve the uniformity of the copper thickness. The aperture of the second through hole 71 is smaller than that of the first through hole 31, and the second through holes 71 distributed on the baffle 7 are sparser than the first through holes 31 distributed on the side panel. In this embodiment, the number of second through holes 71 is 5-7 per square centimeter. The aperture of the second through hole is smaller than that of the first through hole because the smaller the aperture, the less electric force line distribution and chemical solution exchange, and the thinner the copper plating. Therefore, the copper thickness is adjusted by utilizing the geometric shape of the floating frame.

[0029] Circuit board electroplating is an electrochemical reaction process. When the positive and negative electrodes are energized, the electric field lines are distributed in the plating solution. Because there are more electric field lines distributed at the edge of the cathode (circuit board) during electroplating, the more electric field lines are distributed, the thicker the plating will be. Figure 4 As shown, the upper and lower parts of the cathode have more electric lines of force distributed, and the copper thickness is thicker in the areas where the electric lines of force are more distributed during electroplating. In order to make the copper thickness of the upper and lower parts of the cathode (circuit board) as consistent as possible, this embodiment drills a number of circular holes with different upper and lower apertures on the baffle in the floating frame, and uses the geometric shape of the floating frame to adjust the plating layer to achieve better uniformity. In the present invention, the second through hole 71 can be divided into large holes, medium holes, and small holes according to the aperture size. The aperture of the large hole is 8-10mm smaller than the aperture of the first through hole, the aperture of the medium hole is 11-12mm smaller than the aperture of the first through hole, and the aperture of the small hole is 13-14mm smaller than the aperture of the first through hole. The large hole, medium hole, and small hole are arranged in order from top to bottom. Preferably, the aperture of the large hole is 10mm smaller than the aperture of the first through hole, the aperture of the medium hole is 12mm smaller than the aperture of the first through hole, and the aperture of the small hole is 14mm smaller than the aperture of the first through hole.

[0030] The vertical gantry electroplating floating frame of the utility model can block part of the power lines when the baffle is inserted into the slot. The copper amount in the area blocking the power lines can be thinner than that at the clamping point, thereby achieving uniform copper thickness at the clamping point and non-clamping point.

[0031] After testing, the electroplating floating rack of the utility model is used, and the maximum difference in copper thickness between the electroplating clamping point and the opposite side of the clamping point is required to be ≤8um, and the actual measurement is 6.7um. The hole copper requirement is ≥18um, and the actual measurement is 21um at the clamping point and 22.5um opposite the clamping point, which meets the quality requirements and the test results are qualified.

[0032] The above describes the embodiments of the present invention in detail, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations to these embodiments without departing from the principles and spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A vertical gantry electroplating floating frame, characterized in that: It includes two end plates arranged opposite to each other, a bottom plate connecting the two end plates, side plates distributed on both sides of the bottom plate and having a plurality of first through holes, a plurality of connecting blocks for connecting the side plates and the bottom plate, slots provided at both ends of the outer sides of the side plates, and a baffle inserted into the slot and capable of sliding up and down. The connecting blocks on both sides of the bottom plate are symmetrically arranged and V-shaped, the bottom of the circuit board abuts against the connecting blocks, and the baffle is provided with a plurality of second through holes.

2. The vertical gantry electroplating floating frame according to claim 1, characterized in that: The second through holes distributed on the baffle are sparser than the first through holes distributed on the side plates.

3. The vertical gantry electroplating floating frame according to claim 2, characterized in that: The number of the first through holes is 9-10 per square centimeter, and the number of the second through holes is 5-7 per square centimeter.

4. The vertical gantry electroplating floating frame according to claim 1, characterized in that: The diameter of the second through hole is smaller than that of the first through hole.

5. The vertical gantry electroplating floating frame according to claim 4, characterized in that: The aperture of the first through hole is 20-25 mm, and the second through hole can be divided into large hole, medium hole and small hole according to the aperture size. The aperture of the large hole is 8-10 mm smaller than the aperture of the first through hole, the aperture of the medium hole is 11-12 mm smaller than the aperture of the first through hole, and the aperture of the small hole is 13-14 mm smaller than the aperture of the first through hole.

6. The vertical gantry electroplating floating frame according to claim 5, characterized in that: In the second through hole, the large hole, the middle hole and the small hole are arranged in sequence from top to bottom.

7. The vertical gantry electroplating floating frame according to claim 1, characterized in that: The side panels have a height of 25-30 mm and a thickness of 3-4 mm; the baffles have a height of 25-30 mm and a thickness of 3-4 mm.

8. The vertical gantry electroplating floating frame according to claim 1, characterized in that: The clamping slot and the side plate are fixed by welding.

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