JP6909535B2 - Substrate processing equipment and substrate processing method - Google Patents

Description

The present invention relates to, for example, a substrate processing apparatus and a substrate processing method for drilling a multilayer printed circuit board.

In the drilling of a multilayer printed circuit board in which conductor layers and insulating layers are alternately laminated, a so-called blind hole may be formed in which the hole does not penetrate the entire substrate and is only halfway in the depth direction of the substrate. The depth of the blind hole is associated with the position of the conductor layer, such as to the surface of the specific inner conductor layer, from the surface of the specific inner conductor layer to the specified depth, and so on.
Conventionally, in blind hole processing, for example, as disclosed in Patent Document 1, it is detected that a drill has come into contact with the surface of a substrate, and the depth is determined based on the surface position thereof.

However, the depth of the inner conductor layer is not always uniform when viewed in the plane direction of the substrate. Therefore, in the conventional method of determining the depth based on the substrate surface, even if the hole is drilled to a depth that is known in advance, the hole does not reach the surface of the corresponding inner conductor layer, or the hole is drilled deeper than the surface. It is not possible to machine a blind hole with a high precision depth.

Japanese Unexamined Patent Publication No. 2014-113662

Therefore, an object of the present invention is to enable detection of the inner conductor layer of the multilayer printed circuit board so that high-precision machining can be performed.

A typical substrate processing apparatus disclosed in the present application is a processing tool in a substrate processing apparatus in which conductor layers and insulating layers are alternately laminated to process a multilayer printed circuit board having a conductor layer inside in the middle of the thickness direction. A conductor layer detection unit that detects that the conductor layer is sent in the processing direction and comes into contact with the conductor layer, and a conductor layer identification unit that identifies which conductor layer the conductor layer detected by the conductor layer detection unit is. It is characterized by having a depth control unit that controls the processing depth by the processing tool based on the identification result of the conductor layer identification unit.

Further, a typical substrate processing method disclosed in the present application is a substrate processing method in which conductor layers and insulating layers are alternately laminated to process a multilayer printed circuit board having a conductor layer inside in the middle of the thickness direction. A conductor layer detection step of sending a tool in the machining direction to detect contact with the conductor layer, a conductor layer identification step of identifying which conductor layer the conductor layer detected in the conductor layer detection step is, and a conductor layer identification step. It is characterized by having a depth control step for controlling the processing depth by the processing tool based on the identification result in the conductor layer identification step.

According to the present invention, it becomes possible to detect the inner conductor layer of the multilayer printed circuit board and perform high-precision machining with a high accuracy.

It is a figure for demonstrating operation of the drilling apparatus which becomes one Example of this invention. It is a figure which shows the structure of the drilling apparatus which becomes one Example of this invention. It is a figure for demonstrating the spindle in FIG. 2 in more detail. It is a figure for demonstrating the resonance detection part in FIG. 3 in more detail.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4.
FIG. 2 is a diagram showing a configuration of a drilling apparatus according to an embodiment of the present invention. Each component and connecting line in FIG. 2 mainly show what is considered necessary for explaining this embodiment, and does not show all necessary for a drilling apparatus.
In FIG. 2, 1 is a multi-layer printed circuit board to be drilled, 2 is a processing table on which the multi-layer printed circuit board 1 is placed via a lower plate 3 made of a resin material, and 4 is a processing table for drilling holes in the multi-layer printed circuit board 1. The drill 5 is a spindle unit that holds a spindle 6 with a built-in motor that rotates the drill 4. The spindle unit 5 is driven in the vertical direction by the spindle vertical drive unit 8.
The processing table 2 is horizontally driven and positioned by the processing table driving unit 7 so that the drill 4 faces a position where a hole is to be drilled in the multilayer printed circuit board 1. Reference numeral 3 denotes a lower plate interposed between the multilayer printed circuit board 1 and the processing table 2, and serves to prevent the drill 4 from penetrating the multilayer printed circuit board 1 and coming into contact with the processing table 2 for some reason. .. The multilayer printed circuit board 1 may have through holes in addition to the blind holes, and in this case as well, the lower plate 3 serves to prevent the drill 4 from coming into contact with the processing table 2.

A pressure foot 9 for pressing the multilayer printed circuit board 1 during drilling is engaged on the lower side of the spindle 6. The pressure foot 9 is connected to the spindle unit 5 via a cylinder 10, and when the spindle unit 5 is lowered, it is lowered together with the spindle unit 5 until it comes into contact with the upper surface position of the multilayer printed circuit board 1.
The spindle unit 5 and the pressure foot 9 are engaged with each other at a predetermined interval in the height direction, and when the spindle unit 5 is lowered, the spindle unit 5 and the pressure foot 9 are lowered together halfway, and the pressure foot 9 is the upper surface of the multilayer printed circuit board 1. When it comes into contact with the position, the pressure foot 9 stays at that position thereafter, and only the spindle unit 5 is independently lowered so that the drill 4 can make a hole. When the drilling is completed and the spindle unit 5 is raised, the pressure foot 9 is also raised from a certain position.

Reference numeral 11 denotes a substrate top surface sensor composed of a detector 12 fixed to the spindle unit 5 and a rod 13 fixed to the pressure foot 9. When the pressure foot 9 rises and the detector 12 optically detects the tip of the rod 13, an ON signal is output, and when the pressure foot 9 descends and the detector 12 does not detect the tip of the rod 13, an OFF signal is output. It has become.
Therefore, when the spindle unit 5 is lowered, the pressure foot 9 reaches the surface of the multilayer printed circuit board 1, only the pressure foot 9 cannot be lowered any further, and the spindle unit 5 and the pressure foot 9 are vertically displaced from each other. When it is detected, the substrate top surface sensor 11 outputs an ON signal. Further, when the spindle unit 5 is raised thereafter, when the pressure foot 9 is separated from the upper surface position of the multilayer printed circuit board 1, the substrate upper surface sensor 11 outputs an OFF signal.

Reference numeral 14 denotes an overall control unit that controls the rotation of the spindle 6, the processing table drive unit 7, the spindle vertical drive unit 8, and the like to control the entire drilling apparatus. Inside the overall control unit 14, the conductor layer identification unit 15 for identifying the number of the conductor layer each time the conductor layer in the multilayer printed circuit board 1 is detected, and the depth of the blind hole to be machined. A depth control unit 16 for controlling the above is provided. The conductor layer identification unit 15 identifies the number of the conductor layer at that time by counting the number of times the conductor layer is detected.

The overall control unit 14 has a control function other than that described here, and is also connected to a block (not shown). The overall control unit 14 is configured around, for example, a program control processing device, and each component and connection line in the overall control unit 14 includes logical ones. Further, a part of each component may be provided separately from the overall control unit 14.

The overall control unit 14 controls the machining table drive unit 7 while recognizing the two-dimensional position of the machining table 2 based on the feed position information inside the machining table drive unit 7, and also has a spindle vertical drive unit. The spindle vertical drive unit 8 is controlled while recognizing the current height position of the tip of the drill 4 based on the feed position information inside the 8.

FIG. 3 is a diagram for explaining the spindle 6 in FIG. 2 in more detail, and the same spindles as in FIG. 2 are numbered the same. In FIG. 3, the spindle 6 has a structure in which a motor is built, and the rotor shaft 31 is a rotor of the motor. Reference numeral 32 denotes an electrode attached close to the rotor shaft 31 on the stator side for electrostatic coupling with the rotor shaft 31, and is also a terminal of a capacitor detected between the rotor shaft 31 and the ground. Reference numeral 33 denotes a resonance detection unit connected to the electrode 32, and the overall control unit 14 receives the resonance detection signal S from the resonance detection unit 33.

FIG. 4 is a diagram for explaining the resonance detection unit 33 in FIG. 3 in detail. The same items as in FIG. 3 are numbered the same. In FIG. 4, reference numeral 41 denotes a capacitor detected between the electrode 32 and the ground, and the capacitance of the capacitor varies greatly when the tip of the drill 4 is in contact with the conductor layer of the multilayer printed circuit board 1 and when it is not in contact with the conductor layer. Then it becomes smaller.
Reference numeral 42 denotes a transformer whose secondary side is connected to the electrode 32, and its secondary side is connected to the capacitor 41. 43 is an oscillation circuit that oscillates an AC at a frequency at which the capacitor 41 causes parallel resonance when the tip of the drill 4 is in contact with the conductor layer of the multilayer printed substrate 1, and 44 is a primary of the transformer 42 where parallel resonance occurs in the capacitor 41. This is a resonance detection circuit that detects that the impedance seen from the side has increased and the voltage across the primary side has decreased, and sends out a resonance detection signal S.

The drilling apparatus operates as follows. The multilayer printed circuit board 1 to be processed is, for example, as shown in FIG. 1, the conductor layers L1 to L4 and the insulating layers R1 to R3 made of resin are laminated so that the conductor layers and the insulating layers alternate. Taking the case as an example, it will be described with reference to FIGS. 1 and 2. It is assumed that each of the conductor layers L1 to L4 is made of copper foil, and each of the insulating layers R1 to R3 is made of resin.

The overall control unit 14 controls the spindle 6 by the spindle control line R, and while rotating the drill 4, lowers the spindle unit 5 by the spindle vertical drive unit 8. First, when the pressure foot 9 comes into contact with the surface of the multilayer printed circuit board 1, the detection signal from the substrate top surface sensor 11 is input to the overall control unit 14, and the overall control unit 14 uses the feed position information of the spindle vertical drive unit 8 at that time. Based on this, the height position of the surface of the multilayer printed circuit board 1 can be recognized.

When the spindle unit 5 is further lowered and the drill 4 advances in the machining direction, the tip of the drill 4 comes into contact with the first conductor layer L1 on the surface of the multilayer printed circuit board 1 at t1 and from the resonance detection unit 33. The resonance detection signal S is output and received by the conductor layer identification unit 15 of the overall control unit 14. As a result, the conductor layer identification unit 15 whose initial value is zero is counted up in advance, and the content thereof becomes "1". Therefore, it is the conductor that the drill 4 is in contact with the first conductor layer L1. It is identified by the layer identification unit 15.

If the spindle unit 5 is further lowered, the tip of the drill 4 then contacts the second conductor layer L2 at t3, a resonance detection signal S is generated from the resonance detection unit 33, and the conductor layer identification unit 15 Is counted up and the content becomes "2", so that the conductor layer identification unit 15 identifies that the drill 4 has come into contact with the second conductor layer L2.

After that, if the spindle unit 5 is further lowered, the resonance detection signal S is generated from the resonance detection unit 33 at time t5 and t7 each time the tip of the drill 4 comes into contact with the conductor layers L3 and L4. Then, the conductor layer identification unit 15 is counted up, and the contents are incremented by one such as "3" and "4", and the conductor layer identification unit 15 recognizes that the drill 4 has come into contact with the conductor layers L3 and L4. Will be done.

The depth control unit 16 of the overall control unit 14 controls the depth of the blind hole based on the identification result of the conductor layer identification unit 15 as follows.
For example, when the depth of the blind hole is desired to reach the surface of the second conductor layer L2 which is the inner conductor layer, the spindle vertical drive unit is at the time when the content of the conductor layer identification unit 15 becomes "2". Stop driving 8.
Further, when the depth of the blind hole is desired to be set to a position advanced by D from the surface of the third conductor layer L3 which is the inner conductor layer, the content of the conductor layer identification unit 15 is "3". When the feed amount of the spindle vertical drive unit 8 after that point reaches D, the drive of the spindle vertical drive unit 8 is stopped.

In the above embodiment, the first conductor layer L1 of the multilayer printed circuit board 1 is the outer conductor layer, but there is an insulating layer on the first conductor layer L1 and the conductor layer L1 is the inner conductor. Even if the layers are formed, the operations of the conductor layer identification unit 15 and the depth control unit 16 do not change.
Further, in the above embodiment, an upper plate for improving the bite of the drill 4 and preventing the occurrence of burrs and the like may be placed on the first conductor layer L1 which is the outer conductor layer. Here, when the upper plate is made of a metal conductor such as aluminum, this upper plate becomes a conductor layer, so that the first conductor layer L1 is combined and detected as one conductor layer. deal with.
That is, what should be considered is the case where the depth of the blind hole is desired to be from the surface of the first conductor layer L1 to the position advanced by D, but the thickness DX of the upper plate is grasped in advance and the conductor layer. The drive of the spindle vertical drive unit 8 may be stopped when the feed amount of the spindle vertical drive unit 8 from the time t1 when the content of the identification unit 15 becomes “1” becomes D + DX.

In the above embodiment, the conductor layer identification unit 15 identifies the number of the conductor layer at that time by counting the number of times the conductor layer is detected, but other methods may be used. For example, for each of the conductor layers L1 to L4, if the depth ranges H1a to H1b, H2a to H2b, H3a to H3b, and H4a to H4b from the substrate surface are known in advance, the resonance detection unit 33 is located in these ranges. When the resonance detection signal S is output from the conductor layer S, it may be identified that each of the conductor layers L1 to L4 is detected at that time.

The present invention has been described above with reference to an example in which a blind hole is drilled in a multilayer printed circuit board. can do.

1: Multi-layer printed circuit board 2: Processing table 3: Lower plate 4: Drill,
5: Spindle unit, 6: Spindle, 7: Machining table drive unit,
8: Spindle vertical drive unit, 14: Overall control unit, 15: Conductor layer identification unit,
17: Depth control unit, 31: Rotor shaft, 32: Electrode, 33: Resonance detection unit,
41: Capacitor, 42: Transformer, 43: Oscillation circuit, 44: Resonance detection circuit,
L1 to L4: conductor layer, R1 to R3: insulating layer, S: resonance detection signal,
R: Spindle control line

Claims (5)

In a substrate processing apparatus in which conductor layers and insulating layers are alternately laminated and a multilayer printed substrate having a conductor layer inside in the thickness direction is processed, a processing tool is sent in the processing direction and comes into contact with the conductor layer. The processing is performed based on the identification result of the conductor layer detection unit that detects this, the conductor layer identification unit that identifies which conductor layer the conductor layer detected by the conductor layer detection unit is, and the identification result of the conductor layer identification unit. possess a depth control unit for controlling the depth of machining by the tool, the conductor layer identification unit comprises a depth range from the substrate surface of the conductor layer, when the conductive layer detecting section detects contact A substrate processing apparatus characterized in that the conductor layer is identified based on the height position of the tip of the processing tool. The substrate processing apparatus according to claim 1 , wherein the depth control unit stops feeding the processing tool when the conductor layer identification unit identifies a specific conductor layer. In the substrate processing apparatus according to claim 1 or 2 , when the conductor layer identification unit identifies a specific conductor layer and the subsequent feed amount in the processing direction becomes a predetermined value, the depth control unit is described. A substrate processing device characterized by stopping the feeding of processing tools. In the substrate processing apparatus according to claim 1, 2 or 3 , the conductor layer detection unit detects a change in capacitance with the ground when the processing tool contacts the conductor layer and contacts the conductor layer. A substrate processing apparatus characterized in that it detects what has been done. In a substrate processing method in which conductor layers and insulating layers are alternately laminated and a multilayer printed circuit board having a conductor layer inside in the thickness direction is processed, a processing tool is sent in the processing direction to come into contact with the conductor layer. The processing tool is based on the conductor layer detection step for detecting the above, the conductor layer identification step for identifying which conductor layer the conductor layer detected in the conductor layer detection step is, and the identification result in the conductor layer identification step. possess a depth control step of controlling the depth of machining by, said in the conductive layer identification step, a depth range from the substrate surface of the conductor layer, upon detection of the contact in the conductive layer detecting step A substrate processing method characterized in that a conductor layer is identified based on the height position of the tip of a processing tool.

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