CN103781283A - A method for manufacturing a circuit board - Google Patents

Abstract

The present invention provides a circuit board manufacturing method that can manufacture at least two circuits of different thicknesses on the same circuit board substrate. The circuit board manufacturing method basically forms a circuit groove on a first circuit board substrate with a thinner copper foil circuit layer, which can expose the copper foil circuit layer on the other side at the bottom of the groove, and then fills the circuit groove with thick copper by electroplating copper, and in the subsequent process, manufactures the circuit board by a circuit board process to obtain a circuit board with at least two circuits of different thicknesses on the first circuit board substrate. Thereby, the purpose of saving material costs, avoiding the waste of high-priced metals, and reducing pollution sources is achieved.

Description

A method for manufacturing a circuit board

technical field

The present invention relates to the circuit manufacturing technology of printed boards, and in particular refers to a circuit board manufacturing method which is especially suitable for making at least two circuits with different thicknesses on the same circuit board base material.

Background technique

As we all know, the printed circuit board (Printed Circuit Board, PCB) acts as the circuit connection between the electronic components by the circuit layer (copper film) that transmits the telecommunication, and integrates the required circuit network into a plane and distributes it on the surface of the printed circuit board or Three-dimensional circuit layer to form a network of connections between components in different positions.

In principle, the basic materials of general printed circuit boards (hereinafter collectively referred to as substrates) are mostly made of insulating paper, glass fiber cloth or other fiber materials that are laminated with resin-impregnated adhesive sheets (Prepreg). It is formed by coating copper film on one or both sides; as for the conductors used to form the circuits of each layer of the printed circuit board, it can be formed through the electroplated copper via structure.

With the rapid improvement of materials and processing technology, the performance of printed circuit boards is relatively reliable, and can be widely used in different fields, and even become one of the key components of the object of use; Among the electric vehicles attracting worldwide attention, many related circuit layout designs using printed circuit boards to integrate control signals and drive currents have been seen. The key technology is to make circuits with different thicknesses on the substrate of a printed circuit board for use. The thinner circuit constitutes the transmission of the control signal, and the relatively thicker circuit is used to transmit the high-power driving current, so as to reduce the impedance of the driving current and avoid reducing the operating performance due to overheating of the printed circuit board.

It is currently known to manufacture two conventional circuits with different thicknesses on the circuit board base material. The main method is to select a circuit board base material with a copper foil layer on the surface, and the height of the copper foil layer must be greater than the thickness of the thickest circuit, and After completing the circuit etching operation on the copper foil layer on the surface of the circuit board base material, the copper foil height that is considered unnecessary in some circuits is removed to obtain circuits with different thicknesses.

However, the above-mentioned manufacturing method belongs to the subtractive processing technology commonly known in the industry. It not only wastes a lot of high-priced metals in the processing process of different heights, but also consumes more energy and generates a lot of pollution sources due to the repeated execution of the wet process; In particular, circuits with different thicknesses will form obvious height differences on the surface of the printed circuit board, which will affect the processing effect of the subsequent surface treatment, and even cause component assembly to be skewed, making it difficult to control the processing quality.

Contents of the invention

In view of this, the present invention provides a circuit board manufacturing method capable of manufacturing circuits with different thicknesses on the same circuit board base material with relatively low material cost.

The technical solution of the present invention is: the circuit board manufacturing method of the present invention basically includes the following steps: a. providing a first circuit board base material provided with at least one copper foil circuit layer; b facing the first circuit board base material On the other side of the copper foil circuit layer, process and form a circuit groove that at least enables the copper foil circuit layer on the other side to be exposed at the bottom of the groove; c fill the circuit groove with thick copper by electroplating copper; complete the above steps a ~c obtained circuit board, at least one circuit composed of copper foil circuit layer is formed on the same first circuit board base material, and at least one circuit formed by electroplating in the circuit groove and relatively embedded in the first circuit board base material The circuit formed by the thick copper on the surface of the board.

Utilizing the above technical features, at least one circuit with a thickness greater than that of the copper foil circuit layer can be fabricated on the first circuit board base material under the circuit infrastructure of the thinner copper foil circuit layer. So as to achieve the purpose of saving material cost, avoiding waste of high-priced metals, and reducing pollution sources.

According to the above-mentioned main technical features, the circuit board manufacturing method of the present invention further stacks and presses at least two first circuit board substrates that have completed the processing steps a to c, and at least A conductor used to make intended electrical connections.

According to the above-mentioned main technical features, the circuit board manufacturing method of the present invention further provides at least one second circuit board substrate provided with at least one copper foil circuit layer, and at least one first circuit board substrate that has completed the processing steps a~c The material is stacked and pressed against the at least one second circuit board base material, and at least one conductor for forming a predetermined circuit connection is provided between the at least one first circuit board and the at least one second circuit board base material.

In the circuit board manufacturing method, after step b is completed on the first circuit board substrate, a metal film with a predetermined thickness is constructed on the inner wall of the circuit groove, and then thick copper is filled in the circuit groove by electroplating copper.

In the circuit board manufacturing method, after step b is completed on the first circuit board base material, a shielding layer is covered on the surface of the copper foil circuit layer, and then thick copper is filled in the circuit groove by electroplating copper, and after completing the step After c, the masking layer on the surface of the copper foil circuit layer is removed.

In the circuit board manufacturing method, the copper foil circuit layer is provided on the board surface of the first circuit board base material through copper electroplating.

In the circuit board manufacturing method, the copper foil circuit layer is arranged on the board surface of the first circuit board base material by pressing.

Specifically, the circuit board manufacturing method of the present invention has the following beneficial effects.

1. At least one circuit with a thickness greater than that of the copper foil circuit layer can be fabricated on the first circuit board substrate under the circuit infrastructure of the thinner copper foil circuit layer, which relatively saves material costs.

2. Using additive processing technology to build a circuit with a thickness greater than the copper foil circuit layer on the first circuit board substrate, effectively avoiding waste of expensive metals.

3. Using additive processing technology to build a circuit with a thickness greater than the copper foil circuit layer on the first circuit board substrate instead of completing it through repeated etching operations, so pollution sources can be reduced.

4. Since the main body of the circuit, which is thicker than the copper foil circuit layer, goes deep into the surface of the first circuit board base material, it does not need a lot of prepreg (semi-cured film) to fill the glue when it is applied to the lamination of multi-layer boards, and it is not easy to be pressed. There will be no reliability or CAF problems caused by the glass fiber directly contacting the copper layer due to a large amount of resin flowing into the thick copper voids due to excessive or insufficient resin flow.

5. Since the main body of the circuit, which is thicker than the copper foil circuit layer, is relatively embedded in the surface of the first circuit board base material, there is no height difference, and the problem that the green paint (solder mask) is not easy to cover or the text is not easy to print will not be caused.

Description of drawings

Fig. 1 is the basic flowchart of the present invention.

FIG. 2 is a cross-sectional view of the structure of the first circuit board substrate used in the first embodiment of the present invention.

3 is a cross-sectional view of the structure of forming circuit grooves on the surface of the first circuit board substrate according to the present invention.

4 is a cross-sectional view of the structure of filling thick copper in the circuit groove of the first circuit board substrate according to the present invention.

FIG. 5 is a schematic diagram of the action of stacking and pressing a plurality of first circuit board substrates according to the present invention.

FIG. 6 is a cross-sectional view of the stacked and laminated structure of a plurality of first circuit board substrates according to the present invention.

FIG. 7 is a schematic diagram of the action of stacking and pressing the first circuit board base material and the second circuit board base material according to the present invention.

FIG. 8 is a cross-sectional view of the structure in which the first circuit board base material and the second circuit board base material are stacked and pressed together according to the present invention.

FIG. 9 is another cross-sectional view of the structure of the stacked and pressed first circuit board base material and a plurality of second circuit board base materials according to the present invention.

FIG. 10 is a cross-sectional view of the structure of the first circuit board substrate used in another embodiment of the present invention.

FIG. 11 is a cross-sectional view of the structure of a metal film with a predetermined thickness constructed on the wall surface of the circuit groove of the first circuit board substrate according to the present invention.

Description of figure number:

10 The first circuit board base material

11 copper foil circuit layer

12 circuit grooves

13 thick copper

131 metal film

14 conductors

20 second circuit board base material

21 copper foil circuit layer

30 prepreg film.

Detailed ways

As shown in the basic flow chart of the present invention in FIG. 1 , the circuit board manufacturing method of the present invention basically includes the following steps.

a. Provide a first circuit board substrate 10 provided with at least one copper foil circuit layer 11 as shown in FIG. The circuit layer 11, or a copper foil circuit layer is provided on both board surfaces.

b. On the other side of the first circuit board substrate 10 opposite to the copper foil circuit layer 11 , process and form a circuit groove 12 that at least enables the copper foil circuit layer 11 on the other side to be exposed at the bottom of the groove.

c. As shown in FIG. 4 , fill the circuit groove 12 with thick copper 13 by electroplating copper.

In principle, the circuit board manufacturing method of the present invention can form at least two circuits with different thicknesses on the same circuit board substrate 10 (one of which is composed of copper foil circuit layer The circuit formed by 11, another circuit formed by electroplating in the circuit groove 12 and relatively embedded in the thick copper of the first circuit board base material 10 board surface); in application, the available thickness is relatively relatively The thinner circuit (the circuit formed by the copper foil circuit layer 11) is used for the transmission of the control signal (digital control signal), and the relatively thicker circuit (embedded in the first circuit board base material 10 board surface) is used. The circuit) transmits high-power driving current, so as to reduce the impedance of the driving current, avoid circuit burnout or reduce operating performance due to overheating of the printed circuit board.

When the circuit board completed by the present invention is in use, the relatively thicker circuit (the circuit embedded in the first circuit board substrate 10) can also be used as the waste heat discharge channel of the circuit board, so that the circuit board can be used normally. Maintain proper work performance. In particular, the present invention mainly utilizes the above-mentioned technical features to make at least one circuit with a thickness greater than that of the copper foil circuit layer on the first circuit board base material under the thinner copper foil circuit layer infrastructure. So as to achieve the purpose of saving material cost, avoiding waste of high-priced metals, and reducing pollution sources.

Furthermore, when the present invention is implemented, in addition to being provided with copper foil circuit layers on both board surfaces, a circuit board with a plurality of copper foil circuit layers 11 is formed to increase the circuit configuration density. 5, further stack and press at least two first circuit board substrates 10 that have completed the processing steps a to c (stack a plurality of first circuit board substrates 10 with the prepreg 30 shown in the figure Pressing), and as shown in Figure 6, at least one conductor 14 for forming a predetermined circuit connection is provided between each first circuit board base material 10, so that a multi-layer circuit board can be obtained, which can also achieve increased purpose of circuit configuration density.

Also as shown in FIG. 7, at least one second circuit board base material 20 provided with at least one copper foil circuit layer 21 is further provided, and at least one first circuit board base material 10 that has completed the processing steps a to c is combined with the The second circuit board base material 20 is stacked and pressed (the first circuit board base material 10 and the second circuit board base material 20 are stacked and pressed together with the prepreg 30 shown in the figure), and as shown in FIG. 8 , between the first circuit board 10 and the second circuit board substrate 20 is provided with at least one conductor 14 for forming a predetermined circuit connection, so as to achieve the purpose of increasing the circuit configuration density and even increase the circuit configuration density. As shown in FIG. 9, the circuit formed by the thick copper 13 that is filled in the circuit groove 12 and relatively embedded in the first circuit board substrate 10 is completely hidden in the first circuit board 10 and the second circuit board. The inner layer of the board formed by laminating the two circuit board substrates 20 serves as a waste heat discharge channel for the circuit board, so that the circuit board can maintain its proper working performance.

Since the present invention embeds the circuit main body with a thickness greater than the copper foil circuit layer 11 into the board surface of the first circuit board base material 10, it does not need a large amount of prepreg (semi-cured film) to fill the glue when it is applied to the lamination of multi-layer boards. It is not easy to cause slippage and cavitation problems due to excessive or insufficient resin flow during lamination, and there will be no reliability or CAF problems caused by glass fiber directly contacting the copper layer due to a large amount of resin flowing into thick copper voids. In other words, the first circuit board base material 10 used in the present invention can be provided with the copper foil circuit layer 11 on the board surface of the first circuit board base material 10 by means of copper plating, as shown in FIG. The copper foil circuit layer 11 is arranged on the board surface of the first circuit board base material 10 (the copper foil circuit layer 11 is fixed on the first circuit board base material 10 with the prepreg 30 shown in the figure), Highly stable circuit quality can also be obtained.

In addition, before performing the above-mentioned process of filling the circuit groove with thick copper, the first circuit board substrate 10 is first constructed on the inner wall of the circuit groove 12 as shown in FIG. 11 after completing step b. The metal thin film 131 with a predetermined thickness is then filled with thick copper 13 in the circuit groove 12 by electroplating copper (as shown in FIG. 4 ), so as to improve the filling quality of the thick copper 13 .

Furthermore, regardless of whether the first circuit board substrate 10 used in the present invention is designed with a copper foil circuit layer on one side or both sides, the first circuit board substrate 10 can also be further coated with copper foil after step b is completed. The surface of the foil circuit layer is covered with a shielding layer, and then thick copper is filled in the circuit groove by electroplating copper, and the shielding layer on the surface of the copper foil circuit layer is removed after step c is completed to protect the copper foil circuit The layer does not gain thickness for electroplated metal coverage during thick copper fill.

Compared with the conventional prior art, the circuit board manufacturing method of the present invention has the following advantages.

1. At least one circuit with a thickness greater than that of the copper foil circuit layer can be fabricated on the first circuit board base material under the thinner copper foil circuit layer infrastructure, which relatively saves material costs.

2. Using additive processing technology to build a circuit with a thickness greater than the copper foil circuit layer on the first circuit board substrate, effectively avoiding waste of expensive metals.

3. Using additive processing technology to build a circuit with a thickness greater than the copper foil circuit layer on the first circuit board substrate instead of completing it through repeated etching operations, so pollution sources can be reduced.

4. Since the main body of the circuit, which is thicker than the copper foil circuit layer, goes deep into the surface of the first circuit board base material, it does not need a lot of prepreg (semi-cured film) to fill the glue when it is applied to the lamination of multi-layer boards, and it is not easy to be pressed. There will be no reliability or CAF problems caused by the glass fiber directly contacting the copper layer due to a large amount of resin flowing into the thick copper voids due to excessive or insufficient resin flow.

5. Since the main body of the circuit, which is thicker than the copper foil circuit layer, is relatively embedded in the surface of the first circuit board base material, there is no height difference, and the problem that the green paint (solder mask) is not easy to cover or the text is not easy to print will not be caused.

Claims (7)

1. a circuit board manufacturing method, is characterized in that, includes the following step:

A, provide a first circuit board base material that is provided with at least one copper foil circuit layer;

B, in first circuit board base material with respect to the another face of copper foil circuit layer, be processed to form the circuit groove that at least can make the copper foil circuit layer of another side appear at bottom portion of groove;

C, in circuit groove, insert thick copper in electro-coppering mode;

Complete the circuit board that above-mentioned steps a ~ c obtains, on same first circuit board base material, form the circuit that at least one is made up of copper foil circuit layer, and at least one is by being plated in circuit groove and relatively imbedding the circuit that the thick copper of first circuit board backing material plate face forms.

2. a kind of circuit board manufacturing method as claimed in claim 1, it is characterized in that, this circuit board manufacturing method, further by the overlapped pressing of first circuit board base material of at least two completing steps a ~ c procedure for processing, and between each first circuit board, be provided with at least one conductor connecting in order to form predetermining circuit.

3. a kind of circuit board manufacturing method as claimed in claim 1, it is characterized in that, this circuit board manufacturing method, at least one second circuit plate substrate that is provided with at least one copper foil circuit layer is further provided, by the first circuit board base material of at least one completing steps a ~ c procedure for processing and the overlapped pressing of this at least one second circuit plate substrate, and between this at least one first circuit board and this at least one second circuit plate substrate, be provided with at least one conductor connecting in order to form predetermining circuit.

4. a kind of circuit board manufacturing method as described in as arbitrary in claims 1 to 3, it is characterized in that, this circuit board manufacturing method, after first circuit board base material completing steps b, in the metallic film of circuit groove inwall construction predetermined thickness, in circuit groove, insert again afterwards thick copper in electro-coppering mode.

5. a kind of circuit board manufacturing method as described in as arbitrary in claims 1 to 3, it is characterized in that, this circuit board manufacturing method, after first circuit board base material completing steps b, in copper foil circuit layer surface coverage one shielding layer, in circuit groove, insert again afterwards thick copper in electro-coppering mode, and after completing steps c, worn-out the screening on copper foil circuit layer surface layer is removed.

6. a kind of circuit board manufacturing method as described in as arbitrary in claims 1 to 3, is characterized in that this circuit board manufacturing method is located at copper foil circuit layer on the plate face of first circuit board base material via electro-coppering mode.

7. a kind of circuit board manufacturing method as described in as arbitrary in claims 1 to 3, is characterized in that this circuit board manufacturing method is located at copper foil circuit layer on the plate face of first circuit board base material via pressing mode.

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