This application claims priority of Taiwanese Patent Application No. 103145260, filed on Dec. 24, 2014.
Embodiments of the present disclosure generally relate to a method for forming a circuit pattern on a substrate, more particularly to a method for forming a circuit pattern onto an insulating surface of a substrate.
One approach for forming a circuit pattern on a substrate includes the steps of: roughening an insulating surface of a substrate; forming a whole layer of activation material onto the insulating surface of the substrate; removing the activation material located outside a pattern-forming region by laser ablation; forming a first metal layer on the layer of activation material by electroless plating; and forming a second metal layer on the first metal layer by electroplating.
However, such an approach may result in relatively high production costs since forming the whole layer of activation material is relatively expensive. Moreover, the step of removing the activation material may be time consuming and lead to oxidation of the remaining activation material, thereby lowering the production yield of the conventional approach.
Certain embodiments of the disclosure provide a method for forming a circuit pattern that may alleviate at least one of the aforementioned drawbacks of the prior art. Such a method may include the steps of: providing a substrate having an insulating surface including a pattern-forming region; printing only on a portion of the insulating surface including the pattern-forming region with an activation ink, so as to form an activation layer on the portion of the insulating surface; forming a first metal layer on the activation layer by electroless plating; and isolating a patterned portion of the first metal layer, which is formed on the pattern-forming region, from a remaining portion of the first metal layer.
Other features and advantages of the disclosure will become apparent in the following detailed description of the exemplary embodiment with reference to the accompanying drawings, of which:
Referring to
Step 101: providing a substrate 1 having an insulating surface 11 as illustrated in
Step 102: printing only on a portion 111 of the insulating surface 11 of the substrate 1 with an activation ink as illustrated in
It is worth noting that, in certain embodiments, the activation ink may include N-methyl-2-pyrrolidone (NMP) which can slightly etch the insulating surface 11 when the same is being applied onto the insulating surface 11. As such, a conventional step of roughening the insulating surface to increase the bonding strength between the activation layer 2 and the insulating surface 11 can be omitted.
Step 103: forming a first metal layer 31 on the activation layer 2 by electroless plating as illustrated in
Step 104: isolating a patterned portion 4 of the first metal layer 31, which is formed on the pattern-forming region, from a remaining portion 5 of the first metal layer 31. In certain embodiments, Step 104 may include removing part of the first metal layer 31, so as to form a gap 6 along an outer periphery of the pattern-forming region to isolate the patterned portion 4 of the first metal layer 31. The removal of the part of the first metal layer 31 may be conducted by laser ablation. In certain embodiments, the patterned portion 4 of the first metal layer 31 may be surrounded by the remaining portion 5 of the first metal layer 31. It may be noted that, Step 104 may further include isolating a patterned portion of the activation layer 2, e.g., by laser ablation, where the patterned portion of the activation layer 2 is formed on the pattern-forming region and corresponds in position to the patterned portion 4 of the first metal layer 31. However, in certain embodiments where the activation layer 2 is electrically non-conductive, the gap 6 does not need to extend into the activation layer 2 considering the subsequent electroplating process.
Step 105: forming a second metal layer 32 on the patterned portion 4 of the first metal layer 31 within the pattern-forming region, as illustrated in
In certain embodiments, the method may further include a step of removing the remaining portion 5 of the first metal layer 31 which is located outside the pattern-forming region of the insulating surface 11 as illustrated in
In certain embodiments, the method may further include a step of removing part of the activation layer 2 which is located outside the pattern-forming region of the insulating surface 11 as illustrated in
By forming the activation layer 2 only on the portion 111 of the insulating surface 11 in the method according to the present disclosure, the aforesaid drawbacks of the prior art can be prevented.
While the disclosure has been described in connection with what are considered the exemplary embodiments, it is understood that this disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Number | Date | Country | Kind |
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103145260 | Dec 2014 | TW | national |