Manufacturing method of 5OZ thick copper HDI and thick copper plate

Abstract

The invention belongs to the technical field of thick copper power supplies, and discloses a manufacturing method of a 5OZ thick copper HDI and a thick copper plate. The manufacturing method comprises the following steps: manufacturing an L23 daughter board through browning and resin filling a base material; manufacturing an L45 daughter board by browning and resin filling a base material; manufacturing an L67 daughter board by browning and resin filling a base material; carrying out L27 daughter board primary pressing on the manufactured daughter board; based on the L27 daughter board subjected to primary pressing, an L18 mother board is manufactured through secondary pressing and blind hole windowing. According to the invention, the processing difficulty is reduced, and the yield is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of thick copper power supply, and particularly relates to a 5OZ thick copper HDI manufacturing method and thick copper plate. BACKGROUND

[0002] Printed circuit board (PCB), also known as printed circuit board, is an important electronic component. Thick copper plate is defined as thick copper with a copper thickness requirement of 3-6 oz, and is usually used for thick copper power supply, BMS, industrial control, etc. and adopts a processing mode of pressing multiple PP filled adhesives.

[0003] Through the above analysis, the problems and defects of the prior art are that multiple PP pressing is prone to plate sliding, the adhesive is uneven, the thickness of multiple PP is thick, and HDI products cannot be produced. SUMMARY

[0004] To overcome the problems in the related art, the application discloses a 5OZ thick copper HDI manufacturing method and thick copper plate. The purpose is to use resin to fill the gap between the lines to reduce the number of PP layers between the layers, reduce the risk of pressing layer deviation, and meet the product reliability requirements through reliability verification.

[0005] The technical solution is as follows: a 5OZ thick copper HDI manufacturing method, the manufacturing method comprising:

[0006] S1, making L23 sub-plate by brownization and resin filling base material;

[0007] S2, making L45 sub-plate by brownization and resin filling base material;

[0008] S3, making L67 sub-plate by brownization and resin filling base material;

[0009] S4, performing one-time pressing of L27 sub-plate on the sub-plates made in steps S1-S3;

[0010] S5, based on the one-time pressing of L27 sub-plate, making L18 mother plate by two-time pressing and blind hole windowing.

[0011] In step S1, L23 sub-plate manufacturing includes: cutting, drilling, electroplating, resin hole plugging, VCP electroplating, line, etching, AOI, brownization, resin filling base material, baking plate, and transfer pressing.

[0012] In step S2, L45 sub-plate manufacturing includes: cutting, inner layer line, etching, AOI, brownization, resin filling base material, baking plate, and transfer pressing.

[0013] In step S3, L67 sub-plate manufacturing includes: cutting, drilling, electroplating, resin hole plugging, VCP electroplating, line, etching, AOI, brownization, resin filling base material, baking plate, and transfer pressing.

[0014] In step S4, the L27 sub-board manufacturing includes: one-time pressing, drilling, electroplating, resin hole filling, VCP electroplating, circuit, etching, AOI, brown, resin base filling, baking, and transfer pressing.

[0015] In the one-time pressing, rivet heating melting is adopted, 8 rivets are used to heat and melt to fix the PP and the core plate together, and the anti-sliding layer is added to the four sides to prevent the plate from being deviated, and the heating melting parameters include: temperature 250±15℃, time: 70±15s.

[0016] In step 5, the L18 mother board manufacturing includes: two-time pressing, blind hole windowing, laser drilling, through hole drilling, laser AOI, glue removing, hole filling electroplating, through hole electroplating, outer layer circuit, etching, AOI, solder mask, character, surface treatment, molding, electrical measurement, FQC, and reliability test.

[0017] In steps S1-S4, the resin base filling includes: using 32T resin hole filling screen printing, and printing oil twice.

[0018] The printing oil twice includes:

[0019] (1) First printing; using 32T screen printing, the squeegee pressure is set to 6-8 kg / cm 2 , the squeegee angle is adjusted to 6°-15° right, and uniform printing is performed; when printing, the ink penetrates into the hole; the backing plate is designed to be an aluminum sheet with air guide holes or a special air permeable plate, and only 2 / 3 depth is drilled to support the dense area;

[0020] (2) Pre-baking; temperature 70-85℃, time 20-30 minutes;

[0021] (3) Second printing; squeegee pressure 5-7 kg / cm 2 , angle 6°-15°; screen printing lifting height is adjusted to 4-6 mm;

[0022] (4) Final curing; segmented baking, first low-temperature pre-baking, 80℃ / 30min; then high-temperature complete curing, 150℃ / 60min.

[0023] In step S5, in the blind hole windowing step, the windowing size is equal to the laser hole size.

[0024] In the L18 mother board manufacturing, the whole board is covered with dry film, the required laser place is developed, the copper surface is etched away, and the laser penetrates the base material; the anti-stupid points are designed at the four corners of the board.

[0025] Another object of the present application is to provide a thick copper plate, which has a buried hole, a laser hole and a through hole.

[0026] Combining all the above technical solutions, the beneficial effects of this invention are as follows: By optimizing the flow design and process, this invention solves problems such as slippage during the lamination of multiple PP sheets with thick copper plates, uneven glue filling, and the inability to produce HDI products from multiple PP sheets. This invention reduces processing difficulty and improves yield. Based on the factory's conventional practice that lamination of thick copper plates of 5oz and above results in approximately 20% of the total scrap rate, using this solution can reduce scrap by approximately 10%. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure;

[0028] Figure 1 This is a flowchart of the manufacturing method of 5OZ thick copper HDI provided in the embodiments of the present invention;

[0029] Figure 2 This is a schematic diagram of a thick copper plate structure provided in an embodiment of the present invention. Detailed Implementation

[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] The innovations of the 5OZ thick copper HDI manufacturing method and thick copper plate provided in this invention are as follows: This invention uses Line Mask film screen printing resin to fill the gaps between lines to ensure the flatness of the lamination; multiple PP sheets are not required between layers, but a rivet + hot melt production method is required to ensure that there is no layer deviation; thick copper HDI cannot use LDD and a blind hole opening process is required.

[0032] This invention uses resin to fill the gaps between circuits to reduce the number of PP sheets between layers, thereby reducing the risk of lamination layer misalignment, and has been verified to meet product reliability requirements.

[0033] Example 1, such as Figure 1 As shown, the method for fabricating a 5OZ thick copper HDI according to an embodiment of the present invention includes:

[0034] S1, L23 sub-board is made by browning and resin filling of substrate;

[0035] S2, L45 sub-board is made by browning and resin filling of substrate;

[0036] S3, L67 sub-board is made by browning and resin filling of substrate;

[0037] S4, perform L27 sub-board one-time pressing on the sub-boards made in steps S1-S3 above;

[0038] S5 is based on the L27 sub-board that has been laminated once, and the L18 motherboard is made by laminating twice and opening blind holes.

[0039] For example, in step S1, the fabrication of the L23 sub-board includes: material cutting, drilling, electroplating, resin plugging, VCP electroplating, circuitry, etching, AOI, browning (browning parameters: line speed 4m / s, micro-etching amount controlled at 1.5±0.2um), resin filling substrate (browning is required before filling the substrate; the resin plugging screen uses a 32T screen, ink is printed twice, and the board is baked after ink printing; the baking parameters are 150℃ and baking time 2H), baking, and transfer bonding;

[0040] For example, in step S2, the fabrication of the L45 sub-board includes: material cutting, inner layer circuitry, etching, AOI, browning (browning parameters: line speed 4m / s, micro-etching amount 1.5±0.2um), resin filling substrate (browning is required before filling the substrate; the resin filling screen uses a 32T screen, ink is printed twice, and the board is baked after ink printing; the baking parameters are 150℃ and baking time 2H), baking, and transfer bonding;

[0041] For example, in step S3, the fabrication of the L67 sub-board includes: material cutting, drilling, electroplating, resin plugging, VCP electroplating, circuitry, etching, AOI, browning (browning parameters: line speed 4m / s, micro-etching amount controlled at 1.5±0.2um), resin filling substrate (browning is required before filling the substrate; the resin plugging screen uses a 32T screen, ink is printed twice, and the board is baked after ink printing; the baking parameters are 150℃ and baking time 2H), baking, and transfer bonding;

[0042] For example, in step S4, the fabrication of the L27 sub-board includes: one-time lamination (riveting + hot melting), drilling, electroplating, resin plugging, VCP electroplating, circuitry, etching, AOI, browning, resin filling of substrate, baking, and transfer lamination.

[0043] For example, in a single pressing process, rivets are used for heating and melting. Eight rivets are used to heat-melt and fix the PP and core board together. Anti-slip layer is added on all four sides. The heat-melting parameters include: temperature 250±15℃, time: 70±15s.

[0044] For example, in step S5, the L18 motherboard fabrication includes: secondary lamination, blind via opening (using exposure (the window size is designed to be the same as the laser hole size) development + etching method to first etch away the copper in the area to be laser-etched), laser drilling, through-hole drilling, laser AOI, adhesive removal, via filling electroplating, through-hole electroplating, outer layer circuitry, etching, AOI, solder mask, characters, surface treatment, molding, electrical testing, FQC, and reliability testing.

[0045] For example, in the resin filling substrate step, resin is filled in the gap between the wires.

[0046] For example, in the blind hole windowing step, the window size is equal to the laser hole size; the dry film covers the whole board, and the place where laser is needed is developed, the copper surface is etched to allow laser to break through the substrate; the anti-fooling points are designed at the four corners of the board to avoid abnormalities.

[0047] For example, before the manufacturing method of the 50Z thick copper HDI is implemented, material selection needs to be performed; FR-4 (medium and high TG type), and the medium and high TG type is mainly used in the conventional thick copper plate design; resin: the corresponding resin system ink needs to be selected according to the board material;

[0048] It can be known that the present application is based on the prior art, and improvement points are proposed, in steps S1-S3, Line Mask film silk screen printing resin is used to fill the gap between the lines, and the flatness of the pressing is ensured;

[0049] Before the resin fills the substrate, the brown oxidation needs to be enhanced to enhance the bonding force between the resin and the side copper surface;

[0050] The resin filling substrate needs to use 32T screen printing, and a hard rubber squeegee needs to be used to avoid the reverse sticking of the screen to cause the filling to be not full due to the ink.

[0051] The thick copper HDI must use the blind hole windowing process, and the copper thickness is too thick to be penetrated by laser.

[0052] For example, in the resin filling substrate step of steps S1-S4, the secondary ink printing (two times of printing) is the core step:

[0053] (1) first printing (mainly filling holes);

[0054] Purpose: to ensure that the resin in the hole is filled full (the fullness needs to reach 100%-120%);

[0055] Operation points:

[0056] 32T silk screen (higher mesh, finer mesh) is used, the squeegee pressure is set to 6-8 kg / cm, the squeegee angle is adjusted to 6°-15° right, and the squeegee is printed at low speed. 2

[0057] The ink needs to fully cover the screen, and the ink needs to be ensured to penetrate into the hole when squeegeeing to avoid the generation of bubbles.

[0058] Padded plate design: aluminum sheet with air guide holes or special air permeable plate (hole diameter is 1.2mm larger than the plug hole) is used, only 2 / 3 depth is drilled to support the dense area, and the deformation of the board is prevented.

[0059] (2) pre-baking (first curing); ​

[0060] Temperature: 70-85°C, Time: 20-30 minutes (adjust according to ink type)

[0061] Purpose: Preliminary curing of resin, reducing flow deformation during secondary printing.

[0062] (3) Secondary printing (mainly for flattening)

[0063] Purpose: Fill in the recesses of the first filling, ensure the flatness of the orifice.

[0064] Parameter adjustment:

[0065] Squeegee pressure slightly lower than the first (about 5-7 kg / cm 2 ), angle 6°-15°;

[0066] Screen lifting height is adjusted to 4-6mm (lower than conventional silk screen printing), reducing resin tailing.

[0067] (4) Final curing.

[0068] Segmented baking: first low temperature pre-baking (80°C / 30min), then high temperature complete curing (150°C / 60min), to avoid resin shrinkage and cracking.

[0069] Through the above implementation steps, the key parameters of the application are different from the conventional process, see Table 1.

[0070] Table 1 Key parameters of the application different from conventional process

[0071] Process steps 32T overprint special parameters Conventional single pass hole comparison Screen type 32T silk screen (high mesh count fine mesh) Usually aluminum sheet screen or low mesh count silk screen Squeegee pressure First 6-8 kg / cm 2 Second 5-7 kg / cm 2 ]]> Single fixed pressure (usually 5-6 kg / cm 2 )]]> Screen to screen distance 4-6mm (overprint lower) Conventional 10-20mm Curing process Segmented bake (pre-bake + high temperature cure) Single high temperature cure Padded design Air vent + local shallow drilling (anti-deformation) Normal flat plate or no special design

[0072] In the above implementation steps, the process control points are:

[0073] Bubble prevention and control: ink needs to be pre-conditioned for 2 hours, avoid stirring to introduce bubbles. Use vacuum hole machine (if the equipment allows) or optimize the pad plate air guide structure, forcedly discharge the air in the hole.

[0074] Orifice flatness: after secondary printing, it needs to be precisely ground, use non-woven abrasive belt machine to remove excess resin, copper surface depression needs to be ≤15μm.

[0075] Screen maintenance: 32T screen is easy to block, each batch needs to be cleaned and the opening state is checked, the window size in dense hole area needs to be 10-20% larger than the hole diameter.

[0076] Example 2, the method for making 50Z thick copper HDI, the thick copper plate is made as shown in Figure 2 ;

[0077] For example, the production is an 8-layer board design, secondary pressing, there are buried holes, laser holes and through-hole designs in the board.

[0078] In the above embodiments, the description of each embodiment is focused on, and the part not described or recorded in a certain embodiment can be referred to the relevant description of other embodiments.

[0079] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any modification, equivalent replacement and improvement within the technical range disclosed by the present application and within the spirit and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for manufacturing a 5OZ thick copper HDI, characterized in that, The method includes the following steps: S1, L23 sub-board is made by browning and resin filling of substrate; S2, L45 sub-board is made by browning and resin filling of substrate; S3, L67 sub-board is made by browning and resin filling of substrate; S4, perform L27 sub-board one-time pressing on the sub-boards made in steps S1-S3 above; S5 is based on the L27 sub-board that has been laminated once, and the L18 motherboard is made by laminating twice and opening blind holes.

2. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In step S1, the fabrication of the L23 sub-board includes: material cutting, drilling, electroplating, resin plugging, VCP electroplating, circuitry, etching, AOI, browning, resin filling of substrate, baking, and transfer bonding.

3. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In step S2, the L45 sub-board fabrication includes: material cutting, inner layer circuitry, etching, AOI, browning, resin filling of substrate, baking, and transfer bonding.

4. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In step S3, the L67 sub-board fabrication includes: material cutting, drilling, electroplating, resin plugging, VCP electroplating, circuitry, etching, AOI, browning, resin filling of substrate, baking, and transfer bonding.

5. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In step S4, the fabrication of the L27 sub-board includes: primary lamination, drilling, electroplating, resin plugging, VCP electroplating, circuitry, etching, AOI, browning, resin filling of substrate, baking, and transfer lamination. In the first pressing process, rivets are used for heating and melting. Eight rivets are used to heat-melt and fix the PP and core board together. Anti-slip layer is added on all four sides. The heat-melting parameters include: temperature 250±15℃, time: 70±15s.

6. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In step 5, the L18 motherboard fabrication includes: secondary lamination, blind hole opening, laser drilling, through hole drilling, laser AOI, adhesive removal, hole filling electroplating, through hole electroplating, outer layer circuitry, etching, AOI, solder mask, lettering, surface treatment, molding, electrical testing, FQC, and reliability testing.

7. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In steps S1-S4, the resin filling substrate includes: using a 32T resin-filled screen printing plate and printing ink twice.

8. The method for manufacturing a 5OZ thick copper HDI according to claim 7, characterized in that, The second printing ink includes: (1) First printing; use a 32T screen printing plate, and set the squeegee pressure to 6-8 kg / cm². 2 The scraper angle is adjusted to tilt to the right at 6°-15° for even scraping; the ink penetrates into the hole during scraping; the pad design uses an aluminum sheet with air vents or a special breathable plate, and only drills 2 / 3 of the depth to support dense areas; (2) Pre-baking; temperature 70-85℃, time 20-30 minutes; (3) Secondary printing; doctor blade pressure 5-7 kg / cm 2 Maintain the angle between 6° and 15°; adjust the screen lifting height to 4-6mm; (4) Final curing; staged baking, first pre-baking at low temperature, 80℃ / 30min; then high temperature for complete curing, 150℃ / 60min.

9. The method for manufacturing a 5OZ thick copper HDI according to claim 1, characterized in that, In step S5, In the blind hole windowing process, the window size is the same as the laser hole size; In the L18 motherboard manufacturing process, the entire board is covered with dry film, the areas that need laser treatment are developed, the copper surface is etched away, and the laser penetrates the substrate; foolproof points are designed at the four corners of the board.

10. A thick copper plate, characterized in that, The 5OZ thick copper HDI is manufactured using the manufacturing method described in any one of claims 1-9, and the thick copper plate has buried holes, laser holes, and through holes.

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