CN-122002694-A - PCB, and production method and application thereof

Abstract

The invention discloses a PCB and a production method and application thereof, the PCB comprises a PCB substrate, a plurality of bonding pads, a planar transformer and a plurality of circuits are arranged on the PCB substrate, first grooves corresponding to the bonding pads one by one are arranged on the PCB substrate, second grooves corresponding to the planar transformer are arranged on the PCB substrate, copper foil layers are deposited on the surfaces of the PCB substrate corresponding to the inner walls of the first grooves and the circuits, so that the bonding pads and the circuits are formed, tin alloy layers are arranged on the copper foil layers corresponding to the bonding pad areas, the planar transformer is embedded in the second grooves, and the planar transformer comprises a magnetic core and a coil which is electrically connected with the copper foil layers. The invention can effectively avoid the generation of welding spot bubbles, improve welding quality and heat dissipation performance, simplify the production flow, reduce the production cost and improve the product integration level.

Inventors

• ZHOU WEI
• GONG WEILUN
• ZHANG XIANGKUI
• CHEN JIE
• ZHAO QI
• ZHOU YAOHONG
• MOU CHUAN

Assignees

• 重庆青山工业有限责任公司

Dates

Publication Date

20260508

Application Date

20260325

Claims (10)

1. 1. A PCB comprises a PCB substrate, a plurality of bonding pads, a planar transformer and a plurality of circuits are arranged on the PCB substrate, and the PCB substrate is characterized in that a first groove corresponding to the bonding pads one by one and a second groove corresponding to the planar transformer are arranged on the PCB substrate, copper foil layers are deposited on the surfaces of the PCB substrate corresponding to the inner walls of the first grooves and the circuits, so that bonding pads and circuits are formed, tin alloy layers are arranged on the copper foil layers corresponding to the bonding pad areas, the planar transformer is embedded in the second groove, and the planar transformer comprises a magnetic core and a coil, and the coil is electrically connected with the copper foil layers.
2. 2. The PCB of claim 1, wherein the core of the planar transformer comprises a first core and a second core, the first core disposed within the second recess, the second core disposed above the second core.
3. 3. A PCB as claimed in claim 2, wherein the first core is formed by laser machining or mechanical grinding after filling the second recess with magnetic material.
4. 4. A PCB as in claim 3 wherein the first core is an E-core and the second core is an I-core, the first core having an upward slot and a coil at a center post position.
5. 5. A PCB as claimed in claim 1, wherein the first and second grooves are formed by laser cutting or mechanical milling.
6. 6. The PCB of claim 1, wherein the copper foil layer is formed by physical vapor deposition, chemical vapor deposition, or electroplating.
7. 7. A PCB according to claim 1, wherein the tin alloy layer is a Sn-Ag-Cu alloy, and is deposited on the surface of the copper foil layer by physical vapor deposition or chemical vapor deposition.
8. 8. A method of producing a PCB according to any one of claims 1 to 7, comprising the steps of: (1) Processing first grooves corresponding to the bonding pads one by one and second grooves corresponding to the planar transformer on the PCB substrate; (2) Copper foil layers are deposited on the inner wall of the first groove and the surface of the PCB substrate corresponding to the circuits, so that bonding pads and the circuits are formed; (3) Depositing a tin alloy layer on the copper foil corresponding to the bonding pad area; (4) And manufacturing a magnetic core and a coil of the planar transformer in the second groove, and electrically connecting the coil with the copper foil layer.
9. 9. The method for producing a PCB of claim 8, wherein step (4) specifically comprises: 4.1 Filling magnetic materials in the second groove; 4.2 Processing the filled magnetic material into an E-shaped magnetic core, wherein the notch of the E-shaped magnetic core faces upwards; 4.3 Depositing and forming a coil at the middle column position of the E-shaped magnetic core, wherein the coil is electrically connected with the copper foil layer; 4.4 And installing an I-shaped magnetic core above the E-shaped magnetic core, and combining the I-shaped magnetic core in a pressing or gluing mode to form the complete planar transformer.
10. 10. Use of a PCB according to any of claims 1-7 in motor control boards, drive boards and power boards.

Description

PCB, and production method and application thereof Technical Field The invention belongs to the technical field of electric control, and relates to a PCB, in particular to a PCB, a production method and application thereof. Background An electric control circuit board (PCB) is used as a core component of a motor controller, a driving board, a power board and the like, and is widely applied to the fields of electric automobiles, aerospace, industrial automation, medical equipment, consumer electronics and the like. The main functions of the device are to realize electric energy conversion, signal control and power driving, and have extremely high requirements on welding reliability, heat dissipation performance and long service life. Currently, the main surface treatment methods of the PCB pads in the market include gold plating (ENIG), organic solderable protective film (OSP), silver plating, tin spraying, hot air leveling, and the like. In actual production, it is often necessary to brush solder paste on the pads, and about 50% of the solder paste is flux. In the reflow soldering or wave soldering process, the soldering flux is heated and volatilized, so that bubbles are easily formed in the welding spots, the void ratio of the welding spots is increased, and the welding strength, the conductivity and the heat dissipation efficiency are affected. Particularly, under the application scene of high power density, the bubble of the welding spot can obstruct heat conduction, so that local temperature rise is too high, further the aging of components is accelerated, and the reliability and the service life of the whole machine are reduced. In addition, when the planar transformer is designed by the traditional PCB, only two through holes are reserved for subsequent installation, and the procedures of dispensing, grinding, curing and the like are additionally added. This not only increases the complexity of the production line, but also places higher demands on equipment capacity and personnel skills. At present, most factories do not have the assembly capability of planar transformers, if related production lines are introduced, equipment investment and labor cost are greatly increased, and production efficiency is difficult to guarantee. In summary, the existing PCB has obvious disadvantages in terms of welding quality, heat dissipation performance, process flow, integration level, and the like. How to simplify the production process, reduce the manufacturing cost and improve the product integration while guaranteeing the welding reliability is a key technical problem to be solved in the field of electric control circuit boards. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a PCB, a production method and application thereof, and the invention can effectively avoid the generation of solder joint bubbles, improve the welding quality and the heat dissipation performance, simplify the production flow, reduce the production cost and improve the product integration level. The technical scheme of the invention is realized as follows: A PCB comprises a PCB substrate, wherein a plurality of bonding pads, a planar transformer and a plurality of circuits are arranged on the PCB substrate, a first groove corresponding to the bonding pads one by one is formed in the PCB substrate, a second groove corresponding to the planar transformer is formed in the PCB substrate, copper foil layers are deposited on the surfaces of the PCB substrate corresponding to the inner walls of the first grooves and the circuits, so that bonding pads and circuits are formed, tin alloy layers are arranged on the copper foil layers corresponding to the bonding pad areas, the planar transformer is embedded in the second groove, and the planar transformer comprises a magnetic core and a coil which is electrically connected with the copper foil layers. Further, the magnetic core of the planar transformer comprises a first magnetic core and a second magnetic core, the first magnetic core is arranged in the second groove, and the second magnetic core is arranged above the second magnetic core. Further, the first magnetic core is formed by laser processing or mechanical grinding after the second groove is filled with the magnetic material. Further, the first magnetic core is an E-shaped magnetic core, the second magnetic core is an I-shaped magnetic core, the notch of the first magnetic core faces upwards, and a coil is arranged at the middle post position. Further, the first groove and the second groove are formed by laser cutting or mechanical milling. Further, the copper foil layer is formed by physical vapor deposition, chemical vapor deposition or electroplating. Further, the tin alloy layer is Sn-Ag-Cu alloy and is deposited on the surface of the copper foil layer through physical vapor deposition or chemical vapor deposition. The invention also provides a production method of the PCB, which specifical