JPH0257715B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a printed wiring board based on a metal substrate.

[Background technology] Metal-based printed wiring boards have excellent heat dissipation properties due to the high thermal conductivity of the base metal, and can effectively dissipate heat from electronic components mounted on them. It is becoming increasingly used in response to high-density loading. In manufacturing this metal-based printed wiring board, a special manufacturing method is adopted to ensure electrical insulation between the base metal and the printed circuit or through-hole circuit.

That is, as shown in FIG. 3a, through holes 2, 2, . . . for forming through holes are bored in the metal substrate 1,
A metal foil 5 such as a copper foil is layered on the surface of the metal substrate 1 via a prepreg 4, and then heated and pressed. The prepreg 4 can be obtained by impregnating a glass cloth or the like as a base material with a varnish of a thermosetting resin such as an epoxy resin or a phenolic resin, and then heating and drying the impregnated material. By performing heat and pressure molding in this way, the metal foil 5 is laminated on the metal substrate 1 by the insulating adhesive layer 6 formed by the prepreg 4 being cured, and the resin oozing from the prepreg 4 is removed. 7 is filled into the through-holes 2, 2, . . . . In this way, a wiring board 8 as shown in FIG. 2b is manufactured. Next, in this wiring board 8, through-holes 9 are provided in the resin 7 in each of the through-holes 2 by drilling. As shown in FIG. 2c, the inner diameter of the through hole 9 is set smaller than the inner diameter of the through hole 2 for through hole formation, and the inner peripheral surface of the through hole 2 for through hole formation is coated with resin 7. in a state. Then, the metal foil 5 is etched by printed wiring processing according to a conventional method to form a circuit pattern 16, and a metal through-hole plating layer 17 is formed on the inner periphery of the through-hole 9 by through-hole plating, as shown in FIG. 3d. Form it like this. In this case, the circuit pattern 16 is insulated from the metal substrate 1 by the insulating adhesive layer 6, and the through-hole plating layer 17 of the through-hole 9 is insulated from the metal substrate 1 by the resin 7. Insulation will be ensured. Furthermore, printed wiring boards can be obtained as products by printing solder resists and symbol marks.

In manufacturing a printed wiring board in this way, the insulation between the through-hole plating layer 17 of the through-hole 9 and the metal substrate 1 is determined by the inner periphery of the through-hole 2 for through-hole formation. Since the through hole 9 is secured by the resin 7, it is necessary to provide the through hole 9 at the center of the through hole 2. However, if the processing position of the through hole 9 is shifted from the center of the through hole 2 for forming a through hole, it is very difficult to confirm this, and the degree of misalignment between the through hole 9 and the through hole 2 for forming a through hole is very difficult. It is even more difficult to confirm. Therefore, due to misalignment of the drill when processing the through hole 9, the center of the through hole 9 and the center of the through hole 2 for forming the through hole are largely deviated, and the through hole plating layer 17 on the inner surface of the through hole 9 and the through hole This can be confirmed even when there is a very thin part of the resin 7 between the inner circumferences of the forming through-holes 2 and the electrical insulation between the through-hole plating layer 17 and the metal substrate 1 is insufficient. First, there was a problem that there was a risk that the product would be shipped as a defective product.

[Object of the Invention] The present invention has been made in view of the above points, and it is possible to check the positional deviation between the through hole for forming a through hole and the through hole, and the position of the through hole for forming the through hole and the through hole. It is an object of the present invention to provide a method for manufacturing a metal-based printed wiring board that allows the degree of misalignment to be easily confirmed.

[Disclosure of the Invention] According to the method for manufacturing a metal-based printed wiring board according to the present invention, a through-hole 2 for through-hole formation and a plurality of through-holes 3 for detecting drill misalignment each having the same inner diameter are provided in a metal substrate 1, and This metal substrate 1
A wiring board 8 is created by laminating a metal foil 5 on the surface of the board via an insulating adhesive layer 6, and filling the through hole 2 for through hole formation and the through hole 3 for detecting the position of drill deviation with resin 7, and forming the through hole. Through-holes 9 are formed in the wiring board 8 at the positions of the through-holes 2 for drill displacement and the through-holes 3 for detecting drill displacement, each having a diameter smaller than that of the through-hole 2 for through-hole formation and the diameter of the through-hole 3 for detecting drill displacement. and drill misalignment detection hole 1
0 by drilling while maintaining their relative positional relationship, and the inner diameters of the drill deviation detection holes 10 in each of the drill deviation detection through holes 3 are set to different dimensions, and printed wiring processing is performed on this wiring board 8. It is characterized by applying a plating layer 11 for detecting misalignment on the inner circumference of the drill misalignment detection hole 10 at the same time, and by measuring the electrical connection state between the plating layer 11 for detection and the metal substrate 1, The positional relationship between the deviation detection through hole 3 and the drill deviation detection hole 10 can be confirmed, and the positional relationship between the through hole forming through hole 2 and the through hole 9 can be estimated from this positional relationship. The above objects have been achieved in this manner, and the present invention will be described in detail below with reference to Examples.

The metal substrate 1 is formed of a steel plate, iron plate, copper plate, aluminum plate, etc., and is similar to the through hole 9 in a printed wiring board product as shown in FIG.
Through-holes 2, 2, . A plurality of through holes 3, 3, . . . for detecting drill deviation are drilled in the hole. The inner diameters of the through holes 3, 3, . . . for detecting drill deviation are set to be the same.

Then, metal foil 5 such as copper foil or aluminum foil is layered on the front and back surfaces of this metal substrate 1 via prepreg 4 in the same manner as explained in FIG. The metal foil 5 is laminated on the metal substrate 1 by an insulating adhesive layer 6 formed by hardening of the resin inside, and the resin 7 exuding from the prepreg 4 is connected to the through holes 2, 2... for forming through holes and the through hole for detecting drill deviation. hole 3,3
...to be filled. In this way, a wiring board 8 as shown in FIG. 3b and FIG. 1b is produced. Here, when filling the resin 7 into the through-hole forming through-hole 2 and the drill misalignment detection through-hole 3, it is not particularly necessary to completely fill the through-holes 2 and 3 with the resin 7, and at least the through-hole It is only necessary that the inner peripheries of 2 and 3 are completely covered with the resin 7.

Next, by drilling, through holes 9 are formed in the resin 7 at the through holes 2, 2... for through hole formation, and at the same time, the drill deviation detection holes 1 are formed in the resin 7 at the through holes 3, 3... for detecting drill deviation.
0 is formed through. In this drilling process, the relative positional relationship between the center position of each of the through-hole forming through-holes 2, 2... and the center position of the drill deviation detection through-hole 3 is determined as an X coordinate and a Y coordinate.
This can be done using a drill device controlled by numerical control (NC control) or the like to sequentially move the drill bit so as to match this X-Y coordinate. That is, for example, when a through hole 9 is first drilled in the through hole 2 for forming a through hole with a drill bit, the position of the center of each of the through holes 2, 2, etc. for forming a through hole and the drill misalignment can be detected using this as a reference. Through-holes 9 and drills are sequentially inserted into the through-holes 2, 2... for through-hole formation and the through-holes 3, 3... for detecting drill deviation in accordance with the relative positional relationship of the centers of the through-holes 3, 3... The deviation detection hole 10 is drilled with a drill bit.

Therefore, if the center of the through hole 9 provided in the first through hole forming through hole 2 coincides with the center of the through hole forming through hole 2, then all other through hole forming through holes 2 and the through holes formed The center of 9 coincides with the center of the through hole 2 for through hole formation, and the center of the drill displacement detection hole 10 provided in the through hole 3 for detecting drill displacement coincides with the center of the through hole 3 for detecting drill displacement. Become. Conversely, if the center of the through hole 9 provided in the first through hole forming through hole 2 deviates from the center of the through hole forming through hole 2, the through holes 9 provided in all the other through hole forming through holes 2 shift from the center of the through hole forming through hole 2. The center of the drill misalignment detection hole 10 is shifted by the same dimension from the center of the through hole forming through hole 2, and furthermore, as shown in FIG. 1c and FIG. It will be shifted by the same dimension from the center of 3.

At this time, drill deviation detection holes 10, 10, . . . provided in each drill deviation detection through hole 3, 3, .
The inner diameters of the tubes are set to various sizes as shown in FIGS. 1c and 2. Therefore, the drill misalignment detection through holes 3, 3... are set to have the same inner diameter, and the center of each drill misalignment detection through hole 3, 3... is the same as the drill misalignment detection hole 1.
Since the size of the center deviation of 0, 10, etc. is constant, the drill deviation detection hole 10 with a small inner diameter can detect the deviation of a drill with a large inner diameter even if it does not touch the inner peripheral surface of the through hole 3 for detecting drill deviation. The hole 10 is drilled while being in contact with the inner circumferential surface of the drill misalignment detection through hole 3 or digging into the metal substrate 1 from the inner circumferential surface of the drill misalignment detecting through hole 3.

Next, as above, through holes 9, 9...
The wiring board 8 provided with through holes 10, 10, . Possibly through-hole plating layer 1
7 to produce a printed wiring board A as shown in FIG. 3d. At this time, the drill deviation detection hole 10 is also plated with metal to provide a plating layer 11 for detecting deviation as shown in FIG. 1d, and is connected to the circuit pattern 16 as required.

However, in the case formed in this way, the center of the through-hole plating 9 is shifted from the center of the through-hole 2 for through-hole formation, and the drill deviation detection hole 10 is used for detecting drill deviation, as shown in FIG. If the hole is in contact with the inner circumferential surface of the drill misalignment detection hole 3 or is cut into the metal substrate 1 from the inner circumferential surface of the drill misalignment detection through hole 3 , the misalignment formed on the inner circumference of the drill misalignment detection hole 10 may occur. Detection plating layer 11
is formed in contact with the metal substrate 1 on the inner periphery of the through hole 3 for detecting drill deviation.
Then, this plating layer 11 for detecting deviation and the metal substrate 1
The contact state can be detected by applying current to the plating layer 11 for detecting misalignment and inspecting whether or not the plating layer 11 for detecting misalignment and the metal substrate 1 are electrically connected. Therefore, by measuring the electrical connection state between the plating layer 11 for misalignment detection and the metal substrate 1, it is found that the center of the through hole 9 and the center of the through hole 2 for through hole formation are misaligned, and the center of the through hole 9 is It can be inferred that the insulation between the through-hole plating layer 17 of the through-hole 9 and the metal substrate 1 is insufficient because there is a thin part in the resin 7 on the inner periphery of the through-hole 2 for through-hole formation. This means that this product can be rejected as a defective product. Here, the difference between the radius of the largest diameter of the drill deviation detection holes 10 and the radius of the drill deviation detection through hole 3 is set to be smaller than the allowable deviation between the centers of the through hole 9 and the through hole forming through hole 2. This setting ensures that defective products are checked.

Moreover, at this time, the drill deviation detection holes 10, 10... in the drill deviation detection through holes 3, 3...
Of these, the drill deviation detection hole 10 with a smaller inner diameter is not in contact with the inner periphery of the drill deviation detection through hole 3;
The deviation detection hole 10 having a large inner diameter is provided so as to be in contact with the inner periphery of the drill deviation detection through-hole 3 or to bite into the metal substrate 1 from the inner periphery of the drill deviation detection through-hole 3. Since the plating layer 11 for detecting deviation provided in the drill hole 10 is electrically connected to the metal substrate 1, the plating layer 11 for detecting deviation provided in the drill hole 10 is electrically connected to the metal substrate 1. By examining the plating layer 11, it is possible to estimate the size of the deviation between the center of the through hole 9 and the center of the through hole 2 for through hole formation.

That is, the inner diameter a of the through hole 3 for detecting drill deviation
are each 1.5 mm, and each drill deviation detection hole 10,
The inner diameters b ₁ , b ₂ , b ₃ , b ₄ of 10... are b ₁ = 0.7 mm, b ₂ =
0.9 mm, b ₃ = 1.1 mm, b ₄ = 1.3 mm, the center of the drill deviation detection hole 10 and the drill deviation detection through hole 3
If the centers of the holes match, the drill deviation detection hole 10
The dimension between the inner surface of the drill misalignment detection through hole 3 and the inner diameter of the drill misalignment detection through hole 3 is (inner diameter of the drill misalignment detection through hole - inner diameter of the drill misalignment detection hole)/2, so the drill misalignment detection hole 10 with an inner diameter b ₁ 0.4mm in part, inner diameter b ₂
The inner diameter of the drill deviation detection hole 10 is 0.3 mm.
It is 0.2 mm at the part of the drill deviation detection hole 10 of _b3 , and 0.1 mm at the part of the drill deviation detection hole ₁₀ of the inner diameter b4. As shown in FIG. 1c, a drill deviation detection hole 10 with an inner diameter of b ₃ is in contact with the inner circumference of the drill deviation detection through hole 3, and as shown in FIG. If the plating layer 11 is electrically connected to the metal substrate 1, the inner diameter is b ₃
The dimension between the inner surface of the drill misalignment detection hole 10 and the inner surface of the drill misalignment detection through hole 3 should be 0.2 mm, but it is zero, so the center of the drill misalignment detection hole 10 is the center of the drill misalignment detection hole. through hole 3
This means that it is deviated from the center by more than 0.2 mm. Further, if the plating layer 11 for detecting deviation provided in the drill deviation detection hole 10 with an inner diameter b ₂ is not electrically connected to the metal substrate 1, this drill deviation detection hole 10
The dimension between the inner surface of the drill misalignment detection through hole 3 and the inner surface of the drill misalignment detection through hole 3 should be 0.3 mm, but the center of the drill misalignment detection hole 10 deviates from the center of the drill misalignment detection through hole 3 by a dimension of 0.3 mm or more. It means that it is not. Therefore, it can be confirmed that the center of the drill deviation detection hole 10 and the center of the drill deviation detection through hole 3 are deviated by 0.2 to 0.3 mm, and the center of the through hole 9 and the center of the through hole for through hole formation are deviated by 0.2 to 0.3 mm. It can be confirmed that the center of 2 is also shifted by 0.2 to 0.3 mm.

If possible, the plating layer 11 for detecting deviation in the drill deviation detection hole 10 may be formed immediately after forming the through hole 9 and the drill deviation detection hole 10 in FIG. By doing so, it is possible to discover defects in the formation of the through holes 9 before performing printed wiring processing on the wiring board 1.
This eliminates the need for unnecessary printed wiring processing.

[Effects of the Invention] As described above, in the present invention, a through-hole for forming a through-hole and a plurality of through-holes for detecting drill deviation, each having the same inner diameter, are provided in a metal substrate, and an insulating adhesive is attached to the surface of the metal substrate. A wiring board is created by laminating metal foil through layers and filling the through holes for forming through holes and the through holes for detecting drill misalignment position with resin. A through hole and a drill misalignment detection hole are drilled to maintain a relative positional relationship with each other at the position of the hole, and a printed wiring process is applied to this wiring board, and a plating for misalignment detection is attached to the inner circumference of the drill misalignment detection hole. Since a layer is applied, if the center of the through hole is offset from the center of the through hole for through hole formation, the center of the drill misalignment detection hole will also be offset from the center of the through hole for drill misalignment detection. When the drill deviation detection hole is provided in contact with the inner periphery of the drill deviation detection through hole due to positional deviation, the plating layer for deviation detection on the inner periphery of the drill deviation detection hole is formed in contact with the metal substrate. In particular, this state can be detected by energizing the plating layer for detecting misalignment, making it possible to prevent defective products from being shipped. In addition, the inner diameter of each drill misalignment detection through hole is set to a different size, so if the drill misalignment detection hole is misaligned, the drill misalignment detection hole with a small inner diameter is the drill misalignment detection through hole. Although it is not in contact with the inner periphery of the drill deviation detection hole, the deviation detection hole with a large inner diameter can be in contact with the inner periphery of the drill deviation detection through hole. By checking the presence or absence of electricity with the board, the relationship between the center of the through-hole and the center of the through-hole for through-hole formation can be calculated from the relationship between the inner diameter of the drill misalignment detection hole and the inner diameter of the drill misalignment detection through-hole. It is possible to estimate the size of the deviation.

[Brief explanation of the drawing]

Figures 1a to d are cross-sectional views of each process in an embodiment of the present invention, Figure 2 is a plan sectional view of a portion of Figure 1d, and Figures 3a to d are manufacturing of metal-based printed wiring boards. FIG. 3 is a cross-sectional view of a part of each process. 1 is a metal substrate, 2 is a through hole for forming a through hole, 3 is a through hole for detecting drill deviation, 4 is a prepreg, 5 is a metal foil, 6 is an insulating adhesive layer, 7 is a resin, 8
9 is a wiring board, 9 is a through hole, 10 is a drill deviation detection hole, and 11 is a plating layer for detecting deviation.

Claims (1)

[Claims] 1 A metal substrate is provided with a through hole for forming a through hole and a plurality of through holes for detecting drill misalignment, each having the same inner diameter, and a metal foil is laminated on the surface of this metal substrate via an insulating adhesive layer, and a through hole for forming a through hole is formed on the surface of the metal substrate. A wiring board is created by filling the holes and through-holes for detecting drill misalignment position with resin, and through-holes for through-hole formation are formed in the wiring board at the positions of the through-holes for forming through-holes and the positions of the through-holes for detecting drill misalignment, respectively. Drilling is performed to maintain the relative positional relationship between a through hole whose diameter is smaller than the diameter of the drill misalignment detection through hole and the diameter of the drill misalignment detection through hole, and the drill misalignment is detected in each drill misalignment detection through hole. A method for manufacturing a metal-based printed wiring board, characterized by setting the inner diameters of the holes to different dimensions, performing printed wiring processing on this wiring board, and applying a plating layer for displacement detection on the inner periphery of the drilled displacement detection hole.