JPS6239095A - Manufacture of metal based printed wiring 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. The metal foils 5 are overlapped and heated and press-molded. Bripreg 4 can be obtained by using a plastic cloth as a base material, impregnating it with a face of thermosetting resin such as epoxy resin or 7-ether resin, and drying it by heating. By performing heat and pressure molding in this way, the metal M5 is laminated on the metal substrate 1 by the insulating adhesive layer 6 formed by the prepreg 4 being cured, and the resin 7 exuding from the prepreg 4 is passed through for through hole formation. Hole 2, 2...
・Fill into. In this way, a wiring board 8 as shown in FIG. 2(b) is produced.Next, in this wiring board 8, through holes 9 are formed by drilling in the resin 7 in each of the through holes 2 for forming through holes. As shown in FIG. 2(c), the through hole 9 has its inner diameter connected to the through hole 2 for through hole formation.
The inner circumferential surface of the through hole 2 is coated with the resin 7. Then, the metal M5 is etched by printed wiring processing according to a conventional method to form a circuit pattern 1G, 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. 2(d).
Let this form. In this case, the circuit pattern 16 is insulated from the metal substrate 1 by the insulating adhesive layer 6, and the through hole 4i17 of the through hole 9 is secured.
Open insulation from the metal substrate 1 is ensured by the tree N7. Furthermore, it can be removed by printing printed circuit boards and symbol marks to obtain printed wiring boards as products.

In manufacturing the 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 If resin on the inner periphery of the through-hole 2 for through-hole formation. 7, the through hole 9 is secured by the through hole 2 for through hole formation.
It is necessary to place it in the center of the However, the processing position of the through hole 9 is the through hole 2 for through hole formation.
It is very difficult to confirm this, and it is even more difficult to confirm the degree of positional deviation between the through-hole 9 and the through-hole 2 for through-hole formation. Therefore, due to the 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 through hole formation are largely deviated, and the through hole plating N17 on the inner surface of the through hole 9 and the center for through hole formation Through hole 2
There is a part where the thickness of the resin 7 is very thin at the opening of the inner periphery, and even if the electrical insulation between the through-hole plating layer 17 and the metal substrate 1 is insufficient, this cannot be confirmed and it may be a defective product. *There was a problem that there was a risk that the product would be shipped.

[Objective of the Invention j The present invention has been made in view of the above-mentioned points, and is a method for checking the positional deviation between the through-hole for forming a through-hole and the through-hole, and for determining 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 Insulating adhesive ff1j on the surface of this metal substrate 1
A wiring board 8 is created by laminating a metal foil 5 through the through hole 6 and shining a tree N7 into the through hole 2 for through hole formation and the through hole 3 for detecting the position of drill deviation. Wi for forming through holes in the wiring board 8 at the position and the position of the drill misalignment detection through hole 3, respectively.
A through hole 9 whose diameter is smaller than the diameter of the ll hole 2 and the diameter of the drill misalignment detection through hole 3 and the drill misalignment detection hole 10 are drilled while maintaining their relative positional relationship.
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 the wiring board 8, and a plating layer for deviation detection is formed on the inner periphery of the drill deviation detection holes 10. 11, the detection plating layer 11 and the metal substrate 1
It is possible to check the positional relationship between the drill deviation detection through hole 3 and the drill deviation detection hole 10 by measuring the electrical connection state between them, and from this positional relationship, it is possible to confirm the positional relationship between the drill deviation detection through hole 3 and the drill deviation detection hole 10. The above object has been achieved by making it possible to estimate the positional relationship with the through hole 9, and the present invention will be described in detail below using examples.

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, . Through holes 3, 3... are bored. The inner diameters of the drill displacement detection through holes 3, 3, . . . are set to be equal.

Then, in the same manner as explained in FIG. 3(a), a metal foil 5 such as W4 foil or aluminum foil is overlaid on the front and back surfaces of this metal substrate 1 via a prepreg 4, and the prepreg 4 is formed by heating and pressure forming. The metal foil 5 is laminated on the metal substrate 1 by an adhesive layer 6 formed by hardening of the resin inside, and the resin 7 oozing from the prepreg 4 is detected by the through-holes 2, 2... for forming through-holes and the drill misalignment. Fill the through holes 3.3... In this way the third
A wiring board 8 as shown in FIG. 1(b) and FIG. 1(IJ) is prepared.

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-holes 2 and 3 with the resin 7.
It is sufficient that at least the inner circumferences of the through holes 2 and 3 are completely covered with the resin 7.

Next, by drilling, a through hole 9 is formed in the resin 7 at the through hole forming through hole 2.2, and at the same time, a drill deviation detection hole is formed in the resin 7 at the drill misalignment detection through hole 3.3... 10 is formed through the hole.

This drilling process consists of through holes 2, 2 and 2 for forming through holes.
... and the center position of the through hole 3 for detecting drill misalignment are taken as the X coordinate and the Y locus line, and the drill bit is adjusted to match the second X-Y coordinate. This can be done using a drill device that is controlled by numerical control (NC control) or the like so as to move sequentially. 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-holes 2 for forming through-holes are sequentially formed in accordance with the relative positional relationship of the centers of the through-holes 3, 3, . . .
．． Through-holes 9 and drill deviation detection holes 10 are drilled with a drill bit in the holes 3, 3, . . .

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 corresponds to 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. It will match. 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, all other through hole forming through holes 2
The center of the through-hole 9 provided in the through-hole is also shifted from the center of the through-hole 2 by the same deviation dimension, and furthermore, as shown in Fig. fjfJ1 (e) and Fig. is shifted from the center of the through hole 3 for detecting drill shift by the same shift dimension.

At this time, each drill misalignment detection through hole 3°3...
The drill deviation detection holes i o, i o, etc. provided in . Therefore, the drill misalignment detection through holes 3, 3... are set to have the same inner diameter, and the drill misalignment detection through holes 3, 3...
The center and drill misalignment detection hole 10.10...
Since the size of the deviation from the center of The drill is processed in a state in which it is in contact with the inner circumferential surface of the through hole 3 for detecting deviation, or in a state in which it bites into the metal substrate 1 from the inner circumferential surface of the through hole 3 for detecting drill deviation.

Next, the wiring board 8 provided with the through holes 9, 9, . . . and the through holes 10, 10, . By forming the circuit pattern 16 and plating the through holes 9 with metal, a through hole plating layer 17 is formed, thereby producing a printed wiring board A as shown in FIG. 3(d). At this time, the drill deviation detection hole 10 is also plated with metal to provide a deviation detection plating layer 11 as shown in FIG. 1(d), and is connected to the circuit pattern 16 as required.

However, in the case where the lever is formed in this way, the center of the through hole 9 is shifted from the center of the through hole 2 for through hole formation, and the drill deviation detection hole 10 as shown in FIG.
If the hole is in contact with the inner circumferential surface of the drill misalignment detection through hole 3 or is cut into the metal substrate 1 from the inner circumferential surface of the drill misalignment detection through hole 3, the inside of the drill misalignment detection hole 10 may be damaged. Displacement detection plating layer 11 provided around the circumference
is the metal substrate 1 at the inner periphery of the through hole 3 for detecting drill deviation.
It is formed in contact with the Then, the contact state between the plating layer 11 for misalignment detection and the metal substrate 1 is changed by applying current to the plating layer 11 for detecting misalignment, and plating JW1 for detecting misalignment.
．． 1 and the metal substrate 1 are electrically connected to each other. Therefore, by measuring the electrical connection state between the displacement detection mechanism 11 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 displaced, and the through hole 9 It can be inferred that there is a thin part in the resin 7 on the inner periphery of the through hole 2 for through hole formation in , and the insulation between the through hole plating layer 17 of the through hole 9 and the metal substrate 1 is insufficient. , this item 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, each drill misalignment detection through hole 3°3...
Drill deviation detection hole 10.10...The drill deviation detection hole 10 with a small inner diameter is not in contact with the inner circumference of the drill deviation detection through hole 3, but the drill deviation detection hole 10 with a large and light inner diameter is A hole 10 for detecting deviation is provided in contact with the inner periphery of the through hole 3 for detecting drill deviation or biting into the metal substrate 1 from the inner periphery of the through hole 3 for detecting drill deviation. Since the plating layer 11 is electrically connected to the metal substrate 1, the metal substrate 1 at each drill deviation detection hole 10, 10...
By examining the plating layer 11 for detecting deviation that is electrically connected to the plating layer 11 for detecting deviation, 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 forming a through hole.

That is, the inner diameter a of the through hole 3 for detecting drill deviation is set to 1.50, and each drill deviation detection hole 1o, io
The inner diameter of..., b2. b, , b, = 0
, 7 mm, b2=0.911II+1, b,=
1, 11!1, b4 = 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 drill misalignment detection hole 10 and the drill misalignment detection through hole 3 match, 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, the drill deviation detection hole 10 with the inner diameter b1 is 0.40-, and the drill deviation detection hole 10 with the inner diameter b2 is 0.40-.
It is 0°3 mII in the part of the inner diameter S, 0°2 mm in the part of the drill deviation detection hole 10 of the inner diameter S, and 0.11 sI11 in the part of the drill deviation detection hole 10 of the inner diameter S. As shown in FIG. 1(c), the drill deviation detection hole 10 of the inner diameter is in contact with the inner circumference of the drill deviation detection through hole 3, and as shown in FIG. If the misalignment detection plating [11] is electrically connected to the metal substrate 1, the dimension between the inner surface of the drill misalignment detection hole 10 with an inner diameter of b and the inner surface of the drill misalignment detection through hole 3 is 0.2 mm. Since this value is zero when it should be m, 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 0.2 mm or more. Furthermore, if the misalignment detection plating NJ11 provided in the drill misalignment detection hole 10 with the inner diameter b2 is not electrically connected to the metal substrate 1, there will be a gap between the inner surface of the drill misalignment detection hole 10 and the inner surface of the drill misalignment detection through hole 3. The dimensions should be 0.3 all, but the center of the drill deviation detection hole 10 does not deviate from the center of the drill deviation detection through hole 3 by more than 0.3 m1m. Therefore, the center of the drill deviation detection hole 10 and the center of the drill deviation detection through hole 3 are 0.
．． 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 0.3 mm. can be confirmed.

Incidentally, if possible, the formation of the plating layer 11 for detecting deviation in the drill deviation detection hole 10 may be performed immediately after the formation of the through hole 9 and the drill deviation detection hole 10 shown in FIG. 1(e). In this way, defective formation of the through holes 9 can be discovered before performing printed wiring processing on the placement 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 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 while maintaining a relative positional relationship with the hole position, and printed wiring processing is applied to this wiring board, and misalignment detection plating is applied to the inner circumference of the drill misalignment detection hole. Since a layer is applied, if the center of the through hole is shifted from the center of the through hole for through hole type m, the center of the drill misalignment detection hole will also be shifted from the center of the drill misalignment detection through hole. Therefore, if the drill misalignment detection hole is provided in contact with the inner circumference of the drill misalignment detection through hole due to positional misalignment, the plating layer for misalignment detection on the inner circumference of the drill misalignment detection hole will be in contact with the metal substrate. This state can be detected by energizing the misalignment detection plating layer, and it is possible to prevent defective products from being shipped. Moreover, since the inner diameter of each drill misalignment detection through hole is set to a different size, when 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 deviation 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 dimensions.

[Brief explanation of the drawing]

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 FIGS. 3(a) to ( d) is a cross-sectional view of a part of each process showing the manufacturing 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 the same 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. The holes are drilled while maintaining the relative positional relationship with the detection holes, and the inner diameters of the drill deviation detection holes in each drill deviation detection through hole are set to different dimensions, and printed wiring processing is performed on this wiring board. A method for producing a metal-based printed wiring board, comprising applying a plating layer for detecting deviation on the inner circumference of a drill deviation detection hole.