JPS62114295A - Manufacture of metal base printed circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 the heat generated by the electronic components mounted on them, allowing for high-density mounting of electronic components. It has come to be widely used in response to the 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. 3(a), through-holes 2, 2, etc. are formed in the metal substrate 1, and copper foil or the like is formed on the surface of the metal substrate 1 through the prepreg 4. metal? Layer i ¥5 and heat and press mold. Prepreg 4 can be obtained by using glass cloth as a base material and impregnating it with a face of thermosetting resin such as epoxy resin or phenol 1000 J (fat) and heating and drying it. By doing this, the metal foil 5 is laminated on the metal substrate 1 by the insulating adhesive layer 6 formed when the prepreg 4 is cured, and the resin 7 oozing from the prepreg 4 is transferred to the through hole for forming the through hole.
, 2... are filled. In this way, Figure 3(b)
A wiring board 8 like this is created. Next, this wiring board 8
In this step, through-holes 9 are formed in the resin 7 in each of the through-holes 2 by drilling. As shown in FIG. 3(C), 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. is in a state of being Then, the metal foil 5 is etched using a printed wiring process 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. 3(d).
Form it like this. In this case, the insulation between the circuit pattern 16 and the metal substrate 1 is ensured by the insulating adhesive layer 6, and the insulation between the through-hole plating layer 17 of the through-hole 9 and the metal substrate 1 is ensured by the resin 7. That will happen. Furthermore, it is possible to obtain a printed wiring board as a product by printing a Tsurugurenost or a symbol mark.

Furthermore, in manufacturing a printed wiring board, the insulation between the through-hole plating layer 17 of the through-hole 9 and the metal substrate 1 is maintained by the resin 7 on the inner periphery of the through-hole 2 for through-hole formation, as described above. Therefore, it is necessary to provide the through hole 9 at the center of the through hole 2 for through hole formation. 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.
It is even more difficult to confirm the degree of misalignment.

Therefore, the center of the through hole 9 and the through hole 2 for through hole formation may be misaligned when drilling the through hole 9.
The center of the resin 7 deviates greatly, and a portion where the thickness of the resin 7 is extremely thin is created between the through-hole plating layer 17 on the inner surface of the through-hole 9 and the inner periphery of the through-hole 2 for through-hole formation.
Even if the electrical insulation between the through-hole plating layer 17 and the metal substrate 1 is not sufficient, this cannot be confirmed and there is a risk that the product may be shipped as a defective product.

[Objective of the Invention J The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to check whether there is any misalignment between the through-hole for forming a through-hole and the through-hole, and to check whether there is any misalignment between the through-hole for forming a 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 easy confirmation of the degree of positional shift.

[Disclosure of the Invention] According to the method of manufacturing a metal-based printed wiring board according to the present invention, a metal substrate 1 is provided with penetration holes 1 and 2 for forming through holes.
A plurality of through-holes 3 for detecting drill misalignment having different inner diameters are provided respectively, and a metal foil 5 is laminated on the surface of the metal substrate 1 via an insulating adhesive layer 6. A wiring board 8 is created by filling the through holes 3 with resin 7, and the through holes 2 for forming through holes are formed in the wiring board 8 at the positions of the through holes 2 for forming through holes and the positions of the through holes 3 for detecting drill deviation. The through hole 9 whose diameter is smaller than the diameter of the through hole 3 for detecting drill misalignment and the drill misalignment detection hole 10 are located in relative positions l! The hole is drilled while maintaining the relationship, and printed wiring is applied to this wiring board 8, and a plating layer 11 for detecting deviation is applied on the inner periphery of the drill deviation detection hole 10. By measuring the electrical connection state between the plating layer 11 and the metal substrate 1, it is possible to confirm the positional relationship between the drill deviation detection through hole 3 and the drill deviation detection hole 10, and from this positional relationship, the through hole can be detected. The above object has been achieved by making it possible to estimate the positional relationship between the formation through-hole 2 and the through-hole 9.The present invention will be described in detail below with reference to a large example.

The metal substrate 1 is made of a steel plate, iron plate, copper plate, aluminum plate, etc., and as shown in FIG. Through-holes 2, 2, . The through holes 3, 3... are bored as round holes.

The inner diameters of the drill misalignment detection through holes 3, 3... are set to be different from each other, and in the embodiment shown in FIG. The inner diameter is set to a to a4 so that it is small. *The through-holes 3 for detecting drill deviation are provided so that the distance between the centers of the adjacent through-holes 3, 3 for detecting drills is equal.

Then, in the same manner as explained in FIG. The metal M5 is laminated on the metal substrate 1 by the insulating adhesive layer 6 formed by curing the resin, and the ntm'i oozing from the prepreg 4 is connected to the through-holes 2, 2... and the through-holes for detecting drill misalignment. 3, 3... is filled. In this way the third
A wiring board 8 as shown in Figures (b) and (b) is created.

Here, when filling the resin 7 into the through-hole forming through-hole 2 and the drill misalignment detection through-hole 3, there is no particular need to completely fill the through-hole 2.3 with the resin 7.
It is sufficient that at least the inner periphery of the through hole 2.3 is completely covered with the resin 7.

Next, by drilling, a through hole 9 is formed in the resin 7 at the through holes 2, 2... for through hole formation, and at the same time, a drill deviation detection hole is formed in the resin 7 at the through holes 3, 3... 10 is formed as a round hole through the hole. In this drilling process, the relative positions r! of the centers of the through-holes 2, 2, . . . This can be done by using a drill device controlled by numerical control (NC1i (111) or the like) to sequentially move the drill bit to match the X8g mark and Yi mark. That is, for example, if a through hole 9 is first drilled in the through hole 2 for forming a through hole with a drill bit, then the position of the center of each of the other through holes 2, 2, . . . is determined based on this hole. Through hole 3°3 for detecting drill misalignment...
Through holes 9 and drill deviation detection holes are sequentially inserted into through holes 2, 2... and through holes 3, 3... for through hole formation, and drill deviation detection holes 3, 3... in accordance with the relative positional relationship of the center positions of 10 is to be 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, all other through hole forming through holes 2
The center of the through hole 9 provided in the through hole 9 coincides with the center of the through hole 2 for through hole formation, and the center of the drill deviation detection hole 10 provided in the through hole 3 for detecting drill deviation coincides with the center of the through hole 3 for detecting drill deviation. will match 6
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 deviation detection hole 10 is shifted from the center of the through hole 2 by the same amount of deviation, and as shown in FIG. 1 (0) and FIG. Through hole 3
It will be shifted by the same amount of shift from the center of.

At this time, each drill misalignment detection through hole 3°3...
The drill deviation detection holes 10, 10, . . . provided in the holes 10, 10, . Therefore, the drill misalignment detection through holes 3, 3... are set to have different inner diameter dimensions, and the drill misalignment detection through holes 3, 3... are set to have different inner diameter dimensions.
The center and drill misalignment detection hole 10, 10・
Since the size of the center deviation is constant, the drill deviation detection hole 10 provided in the large inner diameter drill deviation detection through hole 3 is in contact with the inner peripheral surface of this drill deviation detection through hole 3. Even if there is no problem, the drill deviation detection hole 10 provided in the drill deviation detection through hole 3 with a small inner diameter may be in contact with the inner peripheral surface of the drill deviation detection through hole 3 or the inside of the drill deviation detection through hole 3. The drill will be processed in a state where it bites into the metal substrate 1 from the peripheral surface.

Next, the wiring board 8 provided with the through-holes 9, 9, . . . and the drill misalignment detection holes io, io, . . . as described above is printed and wired, and the metal foil 5 is etched. A circuit pattern 16 is formed by this method, and a through-hole plating layer 17 is formed by plating the through-holes 9 with metal, thereby producing a printed wiring board A as shown in FIG. 3(d). At this time, metal plating is also applied to the drill deviation detection hole 10 to provide a plating layer 1.1 for detecting deviation as shown in FIG. is connected to the circuit pattern 16.

However, in this way the form rI1. In the case where the center of the through hole 9 is shifted from the center of the through hole 2 for through hole formation, the drill misalignment detection hole 10 is aligned with the center of the through hole 3 for detecting drill misalignment, as shown in FIG. 1(e). If the plated layer for misalignment detection provided on the inner periphery of the drill misalignment detection hole 10 is provided in contact with the inner circumferential surface or intruded into the metal substrate 1 from the inner circumferential surface of the through hole 3 for detecting drill misalignment. 11 is formed in contact with the metal substrate 1 at the inner periphery of the through hole 3 for detecting drill deviation. Then, the state of contact between the plating layer 11 for detecting misalignment and the metal substrate 1 is determined by energizing the plating layer 11 for detecting misalignment to test whether or not the plating layer 11 for detecting misalignment and the metal substrate 1 are electrically connected. It can be detected by Therefore, by measuring the electrical ** state between the misalignment detection plating [11] and the metal substrate 1, it was found that the center of the through hole 9 and the center of the through hole 2 for through hole formation were misaligned, and the through hole in the through hole 9 was found to be misaligned. It can be inferred that there is a thin part in the resin 7 on the inner circumference of the forming through-hole 2, and that the insulation between the through-hole plating layer 17 of the through-hole 9 and the metal substrate 1 is insufficient. This means that the product can be rejected as a defective product. Here, the difference between the radius of the smallest diameter of the drill deviation detection through holes 3 and the radius of the drill deviation detection hole 10 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, each drill deviation detection hole 10t10...
and each drill misalignment detection through hole 3, 3...
The drill deviation detection hole 10 is not in contact with the inner periphery of the drill deviation detection through-hole 3 with a large inner diameter, but the drill deviation detection hole 10 is in contact with the inner periphery of the deviation detection through-hole 3 with a small inner diameter. The misalignment detection plating Ivjti, which is provided so as to bite into the metal substrate 1 from the inner periphery of the misalignment detection through hole 3 and is provided in this misalignment detection hole 10, is electrically connected to the metal substrate 1. Therefore, by examining the plating layer 11 for misalignment detection that is electrically connected to the metal substrate 1 in each drill misalignment detection hole 10, 10..., the center of the through hole 9 and the center of the through hole 2 for through hole formation can be determined. It is possible to estimate the size of the deviation.

In other words, the inner diameter of each drill misalignment detection through hole 3 is 8++
a2*a3van as a,==:1.8mm%a2=
1.6mm, az=1.4a+m, an=1.2m+-
Also, if the inner diameter of the drill deviation detection holes 10, 10, etc. is b = 1, Omm, then if the center of the drill deviation detection hole 10 and the center of the drill deviation detection through hole 3 match, then , 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 is (inner diameter of the drill misalignment detection through hole - inner diameter of the drill misalignment detection hole)/2, so the inner diameter a, 0 and 4 m11 for the drill misalignment detection through hole 3 with an inner diameter of fi2, 0 and 3 11 m, and 0 and 2 for the drill misalignment detection through hole 3 with an inner diameter of a3. +++
It is 0.1 mm in the portion of the through hole 3 for detecting drill deviation with I11 and inner diameter a4. As shown in PIS 1 (C), a drill deviation detection hole 10 is in contact with the inner periphery of the drill deviation detection through hole 3 having an inner diameter of a3, and as shown in Fig. If the misalignment detection plating layer 11 provided in the detection hole 10 is electrically connected to the metal substrate 1, the gap between the inner surface of the drill misalignment detection through hole 3 with an inner diameter of a and the inner surface of the drill misalignment detection hole 10 is Dimensions are 0
, 2 am, but it is zero, so the center of the drill deviation detection hole 10 is deviated from the center of the drill deviation detection through hole 3 by a dimension of 0°21 or more. In addition, a plating M for detecting deviation provided in the drill deviation detection hole 10 in the through hole 3 for detecting drill deviation having an inner diameter of a2.
11 is not electrically connected to the metal substrate 1, the inner surface of the drill deviation detection hole 10 and the drill deviation detection through hole 3
The center of the drill deviation detection hole 10 should be 0.3 mm from the inner surface of the drill deviation detection hole 3.
This means that it does not deviate from the center by more than 0.3111 m. Therefore, the center of the drill deviation detection hole 10 and the center of the drill deviation detection through hole 3 are 0.2 to 0.3 as.
It can be confirmed that the center of the through hole 9 and the center of the through hole 2 for through hole formation are also shifted by a dimension of 0.2 to 0.31. It is.

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 double deviation detection hole 10 in FIG. 1(c). By doing this, it is possible to discover defects in the formation of the through holes 9 before performing printed wiring processing on the wiring board 1, and unnecessary printed wiring processing can be avoided. [Effects of the Invention] As described above, in the present invention, a through hole for forming a through hole and a through hole for detecting drill misalignment are provided in a metal substrate, and a metal substrate is formed on the surface of the metal substrate via an insulating adhesive layer. A wiring board is created by forming M layers of RM and filling the through holes for forming through holes and the through holes for detecting drill misalignment position with resin, and then forming the through holes for forming through holes and the positions of the through holes for detecting drill misalignment. The through hole and the drill deviation detection hole are drilled while maintaining their relative positional relationship, and printed wiring is applied to this wiring board, and a plating layer for deviation detection is applied to the inner periphery of the drill deviation detection hole. Therefore, if the center of the through-hole is shifted from the center of the through-hole for through-hole formation, the center of the drill misalignment detection hole will also be shifted from the center of the drill misalignment detection through-hole. If the drill deviation detection hole is provided in contact with the inner periphery of the drill deviation detection through hole, the plating layer for deviation detection on the inner periphery of the drill deviation detection hole will be formed in contact with the metal substrate. This state can be detected by energizing the plating layer for detecting deviation, thereby making it possible to prevent defective products from being shipped. Moreover, each drill misalignment detection through-hole has a different inner diameter, so if the drill misalignment detection hole is misaligned, there is no drill misalignment detection hole on the inner periphery of the drill misalignment detection through-hole with a large inner diameter. The drill deviation detection hole can be in contact with the inner periphery of the 6t and inner diameter locking holes 11 that are not in contact,
By checking the presence or absence of electricity between the plating layer for misalignment detection and the metal substrate in each through-hole for detecting drill misalignment, the through hole is 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 This ends with estimating the size of the deviation between the center of the through hole and the center of the through hole.

[Brief explanation of drawings]

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

Claims (1)

[Claims] (1) A through-hole for through-hole formation and a plurality of through-holes for detecting drill misalignment, each having a different inner diameter, are provided on a metal substrate, and metal foil is laminated on the surface of this metal substrate via an insulating adhesive layer, and the through-hole is formed. A wiring board is created by filling resin into the through-hole for detecting the position of the drill and the through-hole for detecting the position of drill deviation.
At the position of the through-hole for through-hole formation and the position of the through-hole for detecting drill misalignment, there are through-holes with diameters smaller than the diameter of the through-hole for forming through-holes and the diameter of the through-hole for detecting drill misalignment, respectively, and drill misalignment on the wiring board. A metal base characterized in that the holes are drilled by drilling while maintaining a relative positional relationship with the detection holes, and printed wiring is applied to this wiring board, and a plating layer for displacement detection is applied to the inner periphery of the drill displacement detection hole. A method for manufacturing printed wiring boards.