TW201929617A - Flexible substrate - Google Patents

Abstract

The invention provides a flexible substrate comprising a coreless substrate body having a foldable part, and an addition part formed on the substrate body and having a through hole, thereby allowing the foldable part to be exposed from the through hole in addition to the coreless substrate body to reduce the overall thickness and meet the requirement for electronic miniaturization.

Description

Flexible substrate

The invention relates to a package substrate, in particular to a flexible substrate.

Soft and hard combined circuit boards are widely used in smart phone boards, photovoltaic boards, Complementary Metal-Oxide-Semiconductor (CMOS), battery modules and wearable devices.

The traditional soft and hard bonding board coats the soft board structure in the hard board structure, reveals only the parts to be flexed, and replaces the traditional surface welding with interlayer interconnection, so it can not only save the mechanism space and simplify the assembly process, but also Effectively reduce the noise of signals transmitted from the soft board structure to the hard board structure.

Therefore, the advantages of good reliability, ease of assembly, noise suppression, etc., make the soft and hard bonding board grow rapidly in the current use ratio of electronic products, and are particularly suitable for being light, thin, short, and small. Mobile devices and wearable devices.

1A to 1D are schematic cross-sectional views showing a first method of the conventional soft-hard bonding type package substrate 1.

As shown in FIGS. 1A to 1B, a hard board 11 having perforations 110 is attached to opposite sides of a flexible board 10 having a flexible section A, and The through hole 110 corresponds to the flexible segment A, so that the flexible segment A is correspondingly exposed to the through holes 110.

The soft board 10 has a core layer 10a, a first circuit layer 10b disposed on opposite sides of the core layer 10a, a cover layer 10c covering the first circuit layer 10b, and covering the cover. The adhesive layer 10c covers the protective film 10d. For example, the core layer 10a and the first wiring layer 10b are formed by a copper clad laminate (CCL).

The hard board 11 has a hard base material 11a, a metal layer 11b disposed on one side of the hard base material 11a, and a pure rubber material 11c disposed on the other side of the hard base material 11a, and the hard board 11 is The mechanical drilling method penetrates the hard substrate 11a, the metal layer 11b, and the pure rubber material 11c to form the through hole 110, and then adheres to the cover protective film 10d of the soft board 10 with the pure rubber material 11c.

As shown in FIG. 1C, the soft board 10 and the hard board 11 are penetrated by mechanical drilling or laser cauterization to form a plurality of through holes 100.

As shown in FIG. 1D, the metal layer 11b is plated with the conductive material 12a on the entire metal layer 11b and the hole walls of the through holes 100, and the metal layer 11b and the conductive material 12a are patterned and etched. The second circuit layer 12 is formed on the hard substrate 11a, and the hollow conductive vias 13 are formed in the through holes 100 to electrically connect the conductive vias 13 to the first circuit layers 10b. The electrical contact pad 101 and the second circuit layer 12. Thereafter, a solder resist layer 14 (such as ink or green paint) of the second circuit layer 12 is exposed on the hard substrate 11a and the second circuit layer 12 and in the conductive via 13 , but the solder resist is formed. Layer 14 is not formed in the perforations 110.

Therefore, the conventional soft-hard-bond type package substrate 1 is by the flexible segment A The perforation 110 is designed to perform a flexing action.

However, in the conventional soft-hard-bonding type package substrate 1, since the interlayer size variation of the flexible board 10 is large and the bonding process is limited, the interlayer alignment accuracy of the flexible board 10 and the hard board 11 is not good ( The pure rubber material 11c easily biases the hard plate 11 so that the interlayer alignment accuracy of the soft plate 10 and the hard plate 11 is about +/- 100 um), so it is necessary to increase the electrical contact pad 101 of the soft plate 10. The area is prevented from being displaced by the hole position, so that the conductive via hole 13 cannot be connected to the electrical contact pad 101, but the wiring area of the other functional lines of the first circuit layer 10b is also reduced, resulting in the need to increase the soft board 10 The width or the line function of the soft board 10 is reduced. However, if the area of the electrical contact pad 101 is not increased, the distance t between the electrical contact pad 101 and its surrounding lines needs to be increased to avoid the short circuit of the circuit caused by the misalignment of the hole position. However, it is therefore impossible to meet the requirements of fine pitch.

Moreover, since the hard board 11 is adhered to the soft board 10 with its pure rubber material 11c, an overflow e is generated at the intersection of the soft board 10 and the hard board 11 (such as the perforation 110 shown in FIG. 1B). The corner is subjected to the pressing of the hard substrate 11a, the lack of glue, the edge of the plate, and the like, thereby affecting the subsequent assembly and flexing ability.

Moreover, the package substrate 1 is limited by the core layer 10a of the flexible board 10, the thickness of the hard board 11 (a certain thickness to provide a desired hardness), and the double-sided layering (the second circuit layer 12 on the upper and lower sides) The design of the package substrate 1 is difficult to reduce to a thickness of 0.3 mm or less, and thus it is difficult to meet the demand for thinning.

2A to 2D are the second of the conventional soft and hard type package substrate 2 Schematic diagram of the process.

As shown in FIG. 2A to FIG. 2B, a dielectric layer 21 having a through hole 210 is respectively pressed on opposite sides of a flexible board 20 having a flexible segment A, and the through holes 210 correspond to the flexible segment A, The flexible segment A is correspondingly exposed to the through holes 210. Next, a metal layer 21b such as a copper material is formed on the dielectric layer 21, the hole wall of the through hole 210, and the flexible segment A.

The soft board 20 has a core layer 20a, a first circuit layer 20b disposed on opposite sides of the core layer 20a, a cover layer 20c formed on the flexure segment A, and a cover layer 20c. The protective film 20d is covered. For example, the core layer 20a and the first wiring layer 20b are formed of a copper foil substrate (CCL).

The dielectric layer 21 is a prepreg (PP), and the through hole 210 is formed through the dielectric layer 21 by mechanical drilling, and the dielectric layer 21 is combined with the core of the soft board 20 . The layer 20a, the first wiring layer 20b and a portion of the protective film 20d are covered.

As shown in FIG. 2C, the flexible board 20, the dielectric layer 21 and the metal layer 21b are penetrated by mechanical drilling or laser cauterization to form a plurality of through holes 200.

As shown in FIG. 2D, the metal layer 21b is plated with the conductive material 22a on the metal layer 21b and the hole walls of the through holes 200, and then the metal layer 21b and the conductive material 22a are patterned and etched to A second circuit layer 22 is formed on the dielectric layer 21, and a hollow conductive via 23 is formed in the via holes 200 to electrically connect the conductive vias 23 to the first circuit layer 20b. Pad 201 and the second circuit layer 22. Thereafter, an exposed portion is formed on the dielectric layer 21 and the second circuit layer 22 and in the conductive via 23 The solder resist layer 24 (such as ink or green paint) of the second wiring layer 22, but the solder resist layer 24 is not formed in the through hole 210.

Therefore, the conventional soft-bonded package substrate 2 is designed to perform a flexing operation by the design of the flexible segment A and the through hole 210.

However, in the conventional soft-hard-bond type package substrate 2, since the interlayer size of the soft board 20 varies greatly, and in the press-bonding process, the dielectric layer 21 of different materials is required to be combined with high temperature and high pressure, resulting in the package substrate 2 Irregular deformation is easy to occur, and the interlayer alignment accuracy of the flexible board 20 and the dielectric layer 21 is not good (about +/- 100 um), so the area of the electrical contact pad 201 of the flexible board 20 needs to be increased to avoid The hole position is offset such that the conductive via 23 cannot be connected to the electrical contact pad 201, but the wiring area of the other functional lines of the first circuit layer 20b is also reduced, resulting in an increase in the width or reduction of the flexible board 20. The line function of the soft board 20. However, if the area of the electrical contact pad 201 is not increased, the distance t between the electrical contact pad 201 and its surrounding lines needs to be increased to avoid the short circuit of the circuit caused by the misalignment of the hole position. However, it is therefore impossible to meet the requirements of fine pitch.

Furthermore, since the soft and hard junction of the package substrate 2 has two materials such as a dielectric layer 21 of a prepreg (PP) and the cover protective film 20d, after pressing the dielectric layer 21, here It is prone to bulging, which in turn affects the ability of subsequent assembly and flexing.

Moreover, the package substrate 2 is limited by the thickness of the core layer 20a of the flexible board 20 and the cover protective film 20d (the thickness is not broken due to deflection), and the thickness of the dielectric layer 21 (constant) The thickness can provide the required hardness) and the design of the double-sided layer (the second circuit layer 22 on the upper and lower sides), so The thickness h of the package substrate 2 is hard to fall below 0.25 mm, and thus it is difficult to meet the demand for thinning.

3A to 3E are schematic cross-sectional views showing a third method of the conventional soft-hard bonding type package substrate 3.

As shown in FIG. 3A, a hard plate 31 having an opening 311 is provided which includes a hard substrate 31a and an inner wiring layer 31c provided on opposite sides of the hard substrate 31a. For example, the hard substrate 31a and the internal wiring layer 31c are formed by a copper foil substrate (CCL), and the opening 311 is formed by mechanically drilling the hard substrate 31a.

As shown in FIG. 3B, a soft board 30 having a flexible section A is disposed in the opening 311, and has a core layer 30a, and a first circuit layer 30b disposed on opposite sides of the core layer 30a. The cover layer 30c on the flexible segment A and the cover protective film 30d covering the cover layer 30c.

As shown in FIG. 3C, a dielectric layer 31d having a through hole 310 is respectively pressed on opposite sides of the hard board 31 and the soft board 30, and the through holes 310 correspond to the flexible section A, so that the The segment A is correspondingly exposed to the perforations 310. Next, a metal layer 31b such as a copper material is formed on the dielectric layer 31d, the hole wall of the through hole 310, and the flexible segment A. Thereafter, the hard board 31, the dielectric layer 31d and the metal layer 31b are formed to form a plurality of via holes 300, and the dielectric layer 31d and the metal layer 31b are formed to form a plurality of exposed portions of the first circuit layer 30b. Hole 301.

The dielectric layer 31d is a prepreg (PP for short), and the dielectric layer 31d is combined with the hard board 31, a portion of the first circuit layer 30b of the soft board 30, and a portion of the protective film 30d.

As shown in FIG. 3D, the metal layer 31b is plated with the conductive material 32a on the entire metal layer 31b, the hole walls of the through holes 300, and the blind holes 300, and then patterned and etched. The layer 31b and the conductive material 32a are formed on the dielectric layer 31d to form a second circuit layer 32, and are formed in the through holes 300 for electrically connecting the internal circuit layer 31c and the second circuit layer 32. The conductive vias 33 are formed, and the conductive vias 320 for electrically connecting the first and second circuit layers 30b, 32 are formed in the blind vias 301. Then, a build-up line structure 35 for electrically connecting the second circuit layer 32 is formed on the dielectric layer 31d, and an exposed portion of the build-up line structure 35 is formed with an anti-welding portion of the build-up line structure 35. Layer 34 (such as ink or green paint).

As shown in FIG. 3E, the material corresponding to the upper side of the through hole 310 (ie, the build-up line structure 35, the conductive material 32a and the metal layer 31b) is removed by mechanical ablation, and the flexible segment A is exposed (ie, exposed) This covers the protective film 30d).

Therefore, the conventional soft-bonded package substrate 3 is designed to perform a flexing operation by the design of the flexible segment A.

However, in the conventional soft-bond type package substrate 3, since the second wiring layer 32 is formed by a subtractive layer method (that is, by etching the metal layer 31b and the conductive material 32a), it is limited by the capability of the line process. The line width/line spacing (L/S) of the second circuit layer 32 can only be greater than or equal to 40/40 um and cannot be less than 40/40 um.

Furthermore, since the soft and hard interface of the package substrate 3 has both the dielectric layer 31d and the cover protective film 30d, the soft board 30 is likely to occur after the dielectric layer 31d is pressed. Problems such as edge protrusions, PP overflow, etc., which in turn affect the subsequent assembly fit and flexing ability.

Moreover, since the thickness of the hard board 31 needs to match the thickness of the soft board 30 (the soft board 30 needs to have a certain thickness, it does not break due to deflection), so the thickness L of the package substrate 3 is hard to fall to Below 0.25mm, it is difficult to meet the demand for thinning.

Fig. 4 is a schematic cross-sectional view showing a fourth method of the conventional soft-hard bonded package substrate 4.

As shown in FIG. 4, a circuit board 40 having a flexible segment A having a wiring layer 40b, a soft portion 40c and a first dielectric layer 40d is laminated on opposite sides of a core board 9, and the circuit layer is 40b is pressed against the core plate 9, and the first dielectric layer 40d has an opening 400 corresponding to the flexible segment A to expose the soft portion 40c to the opening 400. Next, a second dielectric layer 41 having a via 410 and a protective film 90 are pressed as needed.

Therefore, the conventional soft-hard-bonding type package substrate 4 is designed to perform a flexing operation by the opening 400, the through-hole 410 and the flexible segment A, and the circuit layer 40b is not limited to the circuit-making capability of the subtractive layer method.

However, in the conventional soft-hard-bonding type package substrate 4, since the soft and hard junction of the package substrate 4 has both the soft portion 40c and the first dielectric layer 40d, the second dielectric layer is pressed. After 41, the problem of the corner edge protrusion of the opening 400 (or the perforation 410) is likely to occur due to uneven stress distribution, thereby affecting the subsequent assembly and flexing ability.

Furthermore, the package substrate 4 needs to be provided with the core plate 9, so that the thickness thereof can be reduced to a limited extent, which is disadvantageous for thinning requirements.

Therefore, how to overcome various problems in the prior art has become a problem that is currently being solved.

In view of the above-mentioned deficiencies of the prior art, the present invention provides a flexible substrate, comprising: a substrate body having a coreless form, having a flexure segment and at least one dielectric layer, and forming a material layer of the dielectric layer a mold compound or a primer; and an additive member formed on the substrate body and having perforations to expose the flexible segment to the perforation.

The invention provides a method for manufacturing a flexible substrate, comprising: providing a substrate body, wherein the substrate is in a coreless form and has a flexible segment, and comprises at least one dielectric layer, and the dielectric layer is formed The material is a mold compound or a primer; an add-on is formed on the substrate body, wherein the add-on component comprises an insulating layer, a conductive pillar embedded in the insulating layer, and a stopper penetrating the build-up structure; The stopper is removed such that the extension is formed with a perforation for the flexure to be exposed to the perforation.

In the above flexible substrate and method, the extension comprises an insulating layer and a conductive pillar embedded in the insulating layer. For example, the material forming the insulating layer is a dielectric material which is a mold compound or a primer.

The invention also provides a method for manufacturing a flexible substrate, comprising: forming a substrate body on a carrier board, wherein the substrate system is in a coreless form, and has a flexible segment and at least one dielectric layer, and the The material of the dielectric layer is a mold compound or a primer; and a part of the material of the carrier plate is removed to form a through hole penetrating the carrier plate, and the perforated carrier plate is used as an extension member, and the flexible segment is exposed In the perforation.

In the above flexible substrate and method of manufacture, the extension is a metal plate.

In the above flexible substrate and the two methods, the substrate body further comprises a line structure combined with the dielectric layer.

It can be seen from the above that in the flexible substrate and the two manufacturing methods of the present invention, a build-up material and a product structure different from the prior art are used to greatly increase the circuit density of the soft and hard bonded plate structure and reduce the thickness of the whole substrate. It is especially suitable for high-end mobile device products that require thinning and circuit complexity (or multi-function).

1,2,3,4‧‧‧Package substrate

10,20,30‧‧‧soft board

10a, 20a, 30a‧‧‧ core layer

10b, 20b, 30b‧‧‧ first line layer

10c, 20c, 30c‧‧ ‧ cover layer

10d, 20d, 30d‧‧‧ covered protective film

100,200,300‧‧‧through holes

101,201‧‧‧Electrical contact pads

11,31‧‧‧hard board

11a, 31a‧‧‧hard substrate

11b, 21b, 31b‧‧‧ metal layer

11c‧‧‧ pure rubber

110,210,310,410,640,700‧‧‧Perforation

12,22,32‧‧‧second circuit layer

12a, 22a, 32a‧‧‧ Conductive materials

13,23,33‧‧‧Electrical through holes

14,24,34‧‧‧ solder mask

21, 31d, 550‧‧‧ dielectric layer

301‧‧‧Blind hole

31c‧‧‧Internal circuit layer

311,400‧‧‧ openings

320‧‧‧ Conductive blind holes

35‧‧‧Additional line structure

40‧‧‧ circuit board

40b, 551‧‧‧ circuit layer

40c‧‧‧Soft Department

40d‧‧‧First dielectric layer

41‧‧‧Second dielectric layer

5,6,7‧‧‧flexible substrate

5a, 5b, 60, 70‧‧‧Additional pieces

50‧‧‧Loading board

51‧‧‧First Conductive Column

52‧‧‧Second conductive column

53‧‧‧First insulation

530‧‧‧First perforation

54‧‧‧Second insulation

540‧‧‧Second perforation

55‧‧‧Substrate body

552‧‧‧Electrical conductor

56‧‧‧Surface treatment layer

59a, 59b, 69‧‧ ‧ blocks

62‧‧‧conductive column

64‧‧‧Insulation

651‧‧‧Electromagnetic shielding

77‧‧‧Insulating protective layer

770‧‧‧Open area

771‧‧‧ openings

9‧‧‧ core board

90‧‧‧Protective film

A, F‧‧‧stening section

H, h, L, D, d, R‧‧‧ thickness

E‧‧‧distance

t‧‧‧Overflow

1A to 1D are schematic cross-sectional views showing a first method of a conventional soft-hard bonded package substrate; and FIGS. 2A to 2D are cross-sectional views showing a second method of a conventional soft-hard bonded package substrate; 3A to 3E The figure is a schematic cross-sectional view of a third method of a conventional soft-hard bonded package substrate; FIG. 4 is a cross-sectional view of a fourth method of a conventional soft-hard bonded package substrate; FIGS. 5A to 5F are diagrams of the present invention A schematic cross-sectional view of a first embodiment of a method for producing a flexible substrate; and FIGS. 6A to 6C are schematic cross-sectional views showing a second embodiment of a method for manufacturing a flexible substrate of the present invention; and FIGS. 7A to 7B are diagrams A schematic cross-sectional view of a third embodiment of the method of making a flexible substrate of the present invention.

The embodiments of the present invention are described below by way of specific embodiments. Other advantages and effects of the present invention will be readily apparent to those skilled in the art from this disclosure.

It is to be understood that the structure, the proportions, the size, and the like of the present invention are intended to be used in conjunction with the disclosure of the specification, and are not intended to limit the invention. The conditions are limited, so it is not technically meaningful. Any modification of the structure, change of the proportional relationship or adjustment of the size should remain in this book without affecting the effects and the objectives that can be achieved by the present invention. The technical content disclosed in the invention can be covered. In the meantime, the terms "upper", "lower", "first", "second" and "one" are used in the description for convenience of description, and are not intended to limit the invention. Changes in the scope of implementation, changes or adjustments in their relative relationship, are considered to be within the scope of the present invention.

5A to 5F are schematic cross-sectional views showing a first embodiment of the manufacturing method of the flexible substrate 5 of the present invention.

As shown in FIG. 5A, a plurality of first conductive pillars 51 and stoppers 59a are formed on a carrier plate 50 by a patterning process.

In the present embodiment, the carrier 50 is a metal substrate, a semiconductor substrate or an insulating substrate, and is not particularly limited.

Furthermore, the first conductive pillar 51 and the stopper 59a are made of a metal material such as a copper material, and the materials of the two may be the same or different.

As shown in FIG. 5B, a first insulating layer 53 is formed on the carrier 50 to cover the first conductive pillars 51 and the stoppers 59a, and the surfaces of the first conductive pillars 51 and the stoppers 59a are formed. The surface is flush with the first insulating layer The surface of the first conductive pillar 51 and the stopper 59a are exposed to the first insulating layer 53, and the stopper 59a penetrates the first insulating layer 53.

In this embodiment, the first insulating layer 53 is formed as a hard portion on the carrier plate 50 by a molding method, a coating method, or a pressing method, and the material of the first insulating layer 53 is formed. An electric material, which may be an epoxy resin (Epoxy), and further comprises a molding compound or a primer, such as an epoxy resin (Epoxy Molding Compound, EMC for short), wherein The epoxy molded resin contains a filler, and the content of the filler is 70 to 90% by weight.

As shown in FIG. 5C, a substrate body 55 is formed on the first insulating layer 53, and the substrate body 55 is electrically connected to the first conductive pillars 51.

In this embodiment, the substrate body 55 is in a coreless form, which can be fabricated by a line build-up process. Therefore, the substrate body 55 includes at least one dielectric layer 550 formed by coating. A circuit layer 551 of the dielectric layer 550 and a plurality of blind via conductors 552 disposed in the dielectric layer 550 and electrically connected to the circuit layer 551.

In another embodiment, the substrate body 55 can also be fabricated by a molding process. For example, a circuit layer 551 is formed on the first insulating layer 53 to form a conductive pillar on the circuit layer 551. The dielectric layer 550 is formed by molding to cover the wiring layer 551 and the conductive pillars, so that the conductive pillars serve as the electrical conductors 552, and the number of layers can be increased according to the above steps.

Moreover, the dielectric layer 550 is a soft portion, but the material of the dielectric layer 550 and the material of the first insulating layer 53 may be the same or different. For example, the dielectric layer 550 may be one of epoxy resins. Type while the first insulating layer 53 can be another type or the same type of epoxy resin.

As shown in FIG. 5D, a plurality of second conductive pillars 52 and stops 59b are formed on the substrate body 55, and a second insulating layer 54 is formed on the substrate body 55 to cover the second conductive pillars 52. a stopper 59b, and the surface of the second conductive post 52 is flush with the surface of the stopper 59b on the surface of the second insulating layer 54, so that the second conductive post 52 and the stopper 59b are exposed to the surface The second insulating layer 54 and the stopper 59b penetrate the second insulating layer 54.

In this embodiment, the second conductive post 52 and the stopper 59b are made of a metal material, such as a copper material, and the materials of the two may be the same or different.

Furthermore, the second insulating layer 54 is formed as a hard portion, which is formed by a mold, a coating method or a press-bonding method, and the material forming the second insulating layer 54 is a dielectric material, which may be epoxy. A resin, and the epoxy resin further comprises a mold compound or a primer such as an epoxy molded resin, wherein the epoxy molded resin contains a filler, wherein the filler is contained in an amount of 70 to 90% by weight.

In addition, the material of the second insulating layer 54 and the material of the first insulating layer 53 may be the same or different, and the material of the second insulating layer 54 may be the same as or different from the material of the dielectric layer 550.

As shown in FIGS. 5E and 5F, the carrier plate 50 is removed in a peeling manner, and the stoppers 59a, 59b are removed by etching to form a first through hole 530 on the first insulating layer 53 and A second through hole 540 is formed on the second insulating layer 54 to expose the substrate body 55 to the first and second through holes 530, 540 as the flexible segment F, and the first conductive pillars 51 and the first insulating layer 53 can be regarded as an add-on 5a, and the second conductive pillars 52 and the The second insulating layer 54 can be regarded as another extension 5b.

In this embodiment, when the stopper 59a is removed, part of the material of the substrate body 55 may be removed as needed to extend the first through hole 530 into the substrate body 55. Similarly, the second through hole 540 can also extend into the substrate body 55 as needed.

Moreover, in the subsequent process, the add-on members 5a, 5b can form the surface treatment layer 56 on the first and second conductive posts 51, 52 as needed.

Therefore, the flexible substrate 5 of the present invention directly forms the substrate body 55 on the first insulating layer 53 (that is, the dielectric layer 550 is coated), instead of pressing or bonding the build-up material, The soft and hard interface of the present invention is a direct bonding of the dielectric material (for example, direct bonding of two layers of epoxy resin), thereby completely eliminating the disadvantages of the conventional soft and hard bonding board in the soft and hard junction area, that is, the invention The soft and hard junction area has no problems such as glue overflow, lack of glue, protrusion, etc., and the interlayer alignment accuracy can be improved to +/-25um (the interlayer alignment accuracy of the conventional soft and hard board is +/-100um). ).

Furthermore, the substrate body 55 is in a coreless form, so that the total thickness of the flexible substrate 5 can be greatly reduced. For example, the thickness D of the four-layer plate form can be less than 0.2 mm, such as 0.16 mm, which is smaller than the prior art. The thickness of the four-layer plate form (about 0.25 mm).

Moreover, the substrate body 55 is formed by a semi-additive method using the wiring layer 551 (that is, the wiring layer 551 is directly plated) without etching the metal material, so that the edge of the wiring layer 551 is flat, and the etching process is not performed. The resulting residual problem is beneficial to impedance control, and the line width/line spacing of the circuit layer 551 can be reduced to 20/20 um (the line width/line spacing of the line produced by the conventional subtractive method is the smallest) 40/40um).

In addition, the joint position (ie, the flexure F) of the present invention is patterned and transferred to form thick copper (the stoppers 59a, 59b) and the thick copper is removed by etching (the stoppers 59a, 59b). The shape, size and precision of the flexible segment F are not limited by conventional machining, so that the degree of freedom of the mechanism design can be improved (for example, multiple sets of flexible segments F of any shape can be simultaneously produced). Moreover, since the stoppers 59a, 59b can be fabricated together with the first and second conductive posts 51, 52, the processing cost can be reduced.

In addition, the outermost (ie, outer layer of the hard plate region) contact pads of the flexible substrate 5 of the present invention are formed in the form of copper pillars (ie, the first and second conductive pillars 51, 52), and are made of dielectric materials. (The first and second insulating layers 53, 54) replace the conventional solder resist layer, so the present invention can strengthen the contact pads (the first and second conductive pillars 51, 52) and the dielectric material (the first and the first The bonding force between the two insulating layers 53, 54) improves the wire bonding strength of the subsequent wire bonding process, thereby improving product reliability and packaging capability.

6A to 6C are schematic cross-sectional views showing a second embodiment of the manufacturing method of the flexible substrate 6 of the present invention. The difference between this embodiment and the first embodiment lies in the number of perforations, and the other processes are substantially the same, so only the differences will be described below, and the same points will not be described again.

As shown in FIG. 6A, the substrate body 55 is formed on the carrier 50, and the dielectric layers 550 are formed as soft portions, and the dielectric layer 550 is formed on the carrier 50 by coating.

As shown in FIG. 6B, a plurality of conductive pillars 62 and a stopper 69 are formed on the substrate body 55, and an insulating layer 64 is formed on the substrate body 55 to be packaged. The conductive pillars 62 and the stoppers 69 are covered, and the surfaces of the conductive pillars 62 are flush with the surface of the stoppers 69 on the surface of the insulating layer 64, so that the conductive pillars 62 and the stoppers 69 are exposed. The insulating layer 64.

In this embodiment, the conductive post 62 and the stopper 69 are made of a metal material, such as a copper material, and the materials of the two may be the same or different.

Further, the insulating layer 64 is formed as a hard portion, which is formed by a molding method, a coating method, or a press bonding method, and the material forming the insulating layer 64 is a dielectric material, which may be an epoxy resin, and the epoxy layer may be an epoxy resin. The epoxy resin further includes a mold compound or a primer such as an epoxy molded resin, wherein the epoxy molded resin contains a filler, wherein the filler is contained in an amount of 70 to 90% by weight.

Moreover, the material of the dielectric layer 550 and the material of the insulating layer 64 may be the same or different. For example, the dielectric layer 550 may be one of epoxy type (Epoxy), and the insulating layer 64 may be a ring. Another type or type of epoxy resin (Epoxy).

As shown in FIG. 6C, the stopper 69 is removed by etching to form a through hole 640 on the insulating layer 64 to expose the substrate body 55 to the through hole 640 to expose the substrate body 55 to the portion of the through hole 640. As the flexing segment F. Thereafter, the carrier plate 50 is removed, and the conductive pillars 62 and the insulating layer 64 can be regarded as an extension 60.

In this embodiment, when the stopper 69 is removed by etching, a portion of the conductive pillar 62 is removed from the exposed material, so that the height of the end surface of the conductive pillar 62 is lower than the surface of the insulating layer 64, and It is required to remove part of the metal material of the substrate body 55 to increase the depth of the through holes 640.

Furthermore, when the carrier 50 is removed, the soft board portion can be retained (the substrate The body 55) is an electroplated copper layer (partially the wiring layer 551) on the exposed side as the electromagnetic shielding layer 651 without additionally attaching a silver paste conductive film as an electromagnetic shield.

Moreover, in the subsequent process, a surface treatment layer (not shown) may be formed on the conductive pillars 62 as needed.

Therefore, the flexible substrate 6 of the present invention is directly formed on the single side of the carrier 50 to form the substrate body 55 such that the soft plate portion (the dielectric layer 550) or the hard plate portion (the insulating layer 64) is layered. The number can be arbitrarily chosen without being limited by the symmetrical buildup of the design on both sides of the core layer as in the prior art.

Furthermore, the flexible substrate 6 of the present invention has a soft and hard interface only on a single side of the substrate body 55, and is directly bonded to the two layers of epoxy resin (the dielectric layer 550 and the insulating layer 64). Therefore, the shortcomings of the conventional soft and hard bonding board in the soft and hard junction area can be completely eliminated, that is, the soft and hard junction area of the present invention has no problems such as overflowing glue, lack of glue, protrusion, etc. as in the prior art, and can reduce scratching. Fold variation.

Moreover, the substrate body 55 is in a coreless form, so that the total thickness of the flexible substrate 6 can be greatly reduced. For example, the thickness d of the four-layer plate form can be less than 0.2 mm, which is much smaller than the conventional four-layer plate form. thickness.

In addition, the outermost (ie, outer layer of the hard plate region) contact pad of the flexible substrate 6 of the present invention is formed in the form of a copper pillar (ie, the conductive pillar 62), and is replaced by a dielectric material (the insulating layer 64). The solder resist layer is conventionally used, so that the present invention can strengthen the bonding force between the contact pad (the conductive post 62) and the dielectric material (the insulating layer 64), and improve the wire bonding strength of the subsequent wire bonding process, thereby improving product reliability. With packaging capabilities.

In addition, the connection position (ie, the flexible segment F) of the present invention is formed by image transfer and patterning of thick copper (the stopper 69) and etching to remove thick copper (the stopper 69). The shape, size and precision of the flexure segment F are not limited by conventional machining, so that the degree of freedom of the mechanism design can be improved (for example, multiple sets of flexure segments F of any shape can be simultaneously produced), and because of these stops 69 can be fabricated with the conductive post 62 to reduce processing costs.

7A to 7B are schematic cross-sectional views showing a third embodiment of the manufacturing method of the flexible substrate 7 of the present invention. The difference between this embodiment and the second embodiment lies in the manner in which the perforations are made. The other processes are substantially the same, so only the differences will be described below, and the same points will not be described again.

As shown in FIG. 7A, the process of the sixth embodiment is performed on the substrate body 55 to form an insulating protective layer 77 having a plurality of openings 771 exposing the circuit layer 551 and at least one exposed dielectric layer 550. The opening area 770, and in the embodiment, the carrier board 50 is a metal board.

As shown in FIG. 7B, a portion of the material of the carrier plate 50 is etched away from the position of the opening region 770, so that a hole 700 passing through the carrier plate 50 is formed on the carrier plate 50 corresponding to the opening region 770. The substrate body 55 is exposed to the through hole 700, so that the carrier plate 50 having the through hole 700 is used as an extension member 70 (which can be regarded as a hard portion), and the portion of the substrate body 55 exposed to the through hole 700 is used as a flexible portion. F.

Therefore, the flexible substrate 7 of the present invention uses a metal plate as the carrier plate 50 to perform a build-up process thereon, and retains part of the carrier plate 50 as the extension member 70 for supporting the hard plate region. With heat dissipation use.

Furthermore, the flexible substrate 7 of the present invention has a soft and hard interface only on a single side of the substrate body 55, and is a dielectric material (the dielectric layer 550) and a metal material (the carrier plate 50). The material of the carrier plate 50 is directly etched and removed to form the through hole 700 penetrating the carrier plate 50, thereby completely eliminating the disadvantages of the conventional soft and hard bonding plate in the soft and hard junction area, that is, The soft and hard interface of the invention has no problems such as glue overflow, lack of glue, protrusion, etc. as in the prior art.

Moreover, the joint position (ie, the flexure F) of the present invention is made by etching metal (part material of the carrier plate 50), so the shape, size and precision of the flexure F are not subject to conventional machining. The limitation of the mechanism design can be increased, for example, a plurality of sets of flexible segments F of any shape can be simultaneously produced.

In addition, the substrate body 55 is in a coreless form, so that the total thickness of the flexible substrate 7 can be greatly reduced. For example, the thickness R of the four-layer plate form can be less than 0.2 mm, which is much smaller than the conventional four-layer plate form. thickness.

The invention provides a flexible substrate 5, 6, 7 comprising a substrate body 55 and at least one extension 5a, 5b, 60, 70.

The substrate body 55 is in a coreless form and has at least one flexure segment F.

The extensions 5a, 5b, 60, 70 are formed on the substrate body 55, and the extensions 5a, 5b, 60, 70 have perforations 640, 700 (the first and second perforations 530, 540) to make the The segment F is exposed to the perforations 640, 700 (the first and second perforations 530, 540).

In one embodiment, the substrate body 55 includes at least one dielectric layer 550 and a wiring structure (eg, the wiring layer 551 and/or the conductive body 552) in combination with the dielectric layer 550.

In one embodiment, the extensions 5a, 5b, 60 comprise an insulating layer 64 (the first and second insulating layers 53, 54) and a conductive pillar 62 embedded in the insulating layer 64 (the first Second conductive pillars 51, 52). For example, the material forming the insulating layer 64 (the first and second insulating layers 53, 54) is a dielectric material which is a mold compound or a primer.

In an embodiment, the extension member 70 is a metal plate.

In summary, the flexible substrate of the present invention and the method for manufacturing the same are provided in a coreless form of the substrate body to reduce the total thickness of the flexible substrate, thereby meeting the requirements of thinning.

Moreover, the soft-hard junction is directly combined with the additional component for the dielectric material, so that the soft and hard junction area does not have conventional problems such as overflow glue, lack of glue, protrusion, and the like, and the alignment precision between the layers can be improved.

Moreover, the substrate body is fabricated by a semi-additive method using a circuit layer without etching the metal material to facilitate impedance control, and the line width/line distance can be reduced, so that the requirements of the fine pitch/fine line can be met.

In addition, since the flexure segment is defined by etching the metal material, the shape, size and precision of the flexure segment are not limited by conventional machining, and thus the degree of freedom in mechanism design can be improved.

The above embodiments are intended to illustrate the principles of the invention and its effects, and are not intended to limit the invention. Anyone skilled in the art can modify the above embodiments without departing from the spirit and scope of the present invention. change. Therefore, the scope of protection of the present invention should be as set forth in the appended claims.

Claims (13)

A flexible substrate includes: a substrate body having a coreless form and having a flexible segment and at least one dielectric layer, and the material forming the dielectric layer is a mold compound or a primer; and an additional component, The method is formed on the substrate body and has a through hole to expose the flexible segment to the through hole. The flexible substrate of claim 1, wherein the substrate body further comprises a line structure combined with the dielectric layer. The flexible substrate of claim 1, wherein the additional component comprises an insulating layer and a conductive pillar embedded in the insulating layer. The flexible substrate according to claim 3, wherein the material forming the insulating layer is a dielectric material. The flexible substrate of claim 4, wherein the dielectric material is a mold compound or a primer. The flexible substrate of claim 1, wherein the additional component is a metal plate. A method for manufacturing a flexible substrate, comprising: providing a substrate body having a core portion and having a flexible segment, wherein the substrate system comprises at least one dielectric layer, and the material forming the dielectric layer is a mold a compound or a primer; forming an extension on the substrate body, wherein the extension comprises an insulating layer, a conductive pillar embedded in the insulating layer, and a stopper penetrating the buildup structure; The stopper is removed such that the extension is formed with a perforation for the flexure to be exposed to the perforation. The method of manufacturing a flexible substrate according to claim 7, wherein the substrate body further comprises a line structure combined with the dielectric layer. The method of manufacturing a flexible substrate according to claim 7, wherein the material forming the insulating layer is a dielectric material. The method of manufacturing a flexible substrate according to claim 9, wherein the dielectric material is a mold compound or a primer. A method for manufacturing a flexible substrate, comprising: forming a substrate body on a carrier substrate, wherein the substrate is in a coreless form, and has a flexible segment and at least one dielectric layer, and the dielectric layer is formed The material is a mold compound or a primer; and a part of the material of the carrier is removed to form a perforation through the carrier to make the perforated carrier as an extension and the flexure is exposed to the perforation. The method of manufacturing a flexible substrate according to claim 11, wherein the substrate body further comprises a line structure combined with the dielectric layer. The method of manufacturing a flexible substrate according to claim 11, wherein the carrier plate is a metal plate.