TWI666976B - Flexible substrate and method thereof - Google Patents

Abstract

A flexible substrate includes a coreless substrate body having a flexure section and an add-on formed on the substrate body and having a perforation to expose the flexure section to the perforation. The body is a coreless form, which reduces the total thickness of the flexible substrate and meets the demand for thinning.

Description

Flexible substrate and manufacturing method thereof

The present invention relates to a packaging substrate, in particular to a flexible substrate and a method for manufacturing the same.

Soft-hard circuit boards are currently widely used in smart phone boards, optoelectronic boards, complementary metal-oxide semiconductors (CMOS for short), battery modules and wearable devices.

The traditional soft-hard board combines the soft-board structure in the hard-board structure, exposing only the parts that need to be bent, and replacing the traditional surface welding with interlayer interconnections, so it can not only save mechanism space and simplify the assembly process, but also Effectively reduce the problem of noise transmitted from the soft board structure to the hard board structure.

Therefore, with its advantages of good reliability, ease of assembly, and noise suppression, the combination of soft and hard boards has grown rapidly in the current proportion of electronic products, and is particularly suitable for applications that require lightness, thinness, shortness, and smallness. Mobile and wearable devices.

Figures 1A to 1D are schematic cross-sectional views of the first manufacturing method of a conventional flexible-hard-type package substrate 1.

As shown in Figs. 1A to 1B, a rigid plate 11 having a perforation 110 is attached to two opposite sides of a flexible plate 10 having a bending section A, and these The perforations 110 correspond to the flexure sections A, so that the flexure sections A are exposed correspondingly to the perforations 110.

The flexible board 10 has a core layer 10a, a first circuit layer 10b provided on opposite sides of the core layer 10a, a coverly adhesive layer 10c covering the first circuit layer 10b, and covering the cover. The adhesive layer 10c is covered with a protective film 10d. For example, a copper clad laminate (CCL) is used to fabricate the core layer 10a and the first circuit layer 10b.

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

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 used to electroplat a conductive material 12a on the entire layer of the metal layer 11b and the hole walls of the through holes 100, and then pattern-etch the metal layer 11b and the conductive material 12a. A second circuit layer 12 is formed on the hard substrate 11a, and a hollow conductive via 13 is formed in the through holes 100, so that the conductive via 13 is electrically connected to the first circuit layers 10b The electrical contact pad 101 and the second circuit layer 12. After that, an exposed part of the solder resist layer 14 (such as ink or green paint) of the second circuit layer 12 is formed on the hard substrate 11a and the second circuit layer 12 and in the conductive through hole 13, but the solder resist The layer 14 is not formed in the through hole 110.

Therefore, the conventional flexible and rigid package substrate 1 uses the flexure A And the perforation 110 is designed to perform a flexing action.

However, in the conventional soft-hard combined packaging substrate 1, the inter-layer alignment accuracy of the soft board 10 and the hard board 11 is poor due to the large inter-layer size variation of the soft board 10 and the limitation of the bonding process. The pure rubber material 11c easily deviates the hard board 11 and causes the interlayer alignment accuracy of the soft board 10 and the hard board 11 to be about +/- 100um), so the electric contact pad 101 of the soft board 10 needs to be increased. To prevent the conductive vias 13 from being connected to the electrical contact pads 101, but also reduce the wiring area of other functional circuits of the first circuit layer 10b, resulting in the need to increase the flexible board 10. The width of the flexible board 10 may be 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 circuits needs to be increased to avoid the problem of short circuit caused by the misalignment of the hole position. However, it cannot meet the requirements of fine pitch.

In addition, because the hard board 11 is adhered to the soft board 10 with its pure rubber material 11c, the overflow of the soft board 10 and the hard board 11 will cause an overflow of glue e (such as the perforation 110 shown in FIG. 1B). The corners are pressed by the hard substrate 11a), lack of glue, and board edge depression, etc., which further affect the subsequent assembly, bonding and bending capabilities.

In addition, the package substrate 1 is limited by the core layer 10a of the flexible board 10, the thickness of the rigid board 11 (a certain thickness can provide the required hardness) and the double-sided build-up (the second circuit layer 12 on the upper and lower sides) ) Design, it is difficult to reduce the thickness H of the package substrate 1 to less than 0.3 mm, and it is difficult to meet the demand for thinning.

Figures 2A to 2D are the second of the conventional soft-hard combined packaging substrate 2 Schematic sectional view of the manufacturing method.

As shown in FIGS. 2A to 2B, a dielectric layer 21 having perforations 210 is pressed on opposite sides of a flexible board 20 having a flexure section A, and the perforations 210 correspond to the flexure section A. The flexures A are exposed correspondingly to the perforations 210. Next, a metal layer 21b such as a copper material is formed on the dielectric layers 21, the hole walls of the through holes 210, and the flexure A.

The flexible board 20 has a core layer 20a, first circuit layers 20b provided on opposite sides of the core layer 20a, a cover rubber layer 20c formed on the flexure A, and a cover rubber layer 20c that covers the cover rubber layer 20c. Cover the protective film 20d. For example, the core layer 20a and the first circuit layer 20b are fabricated by using 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. The dielectric layer 21 is combined with the core of the flexible board 20. The layer 20a, the first wiring layer 20b, and a partial covering protective film 20d.

As shown in FIG. 2C, the soft board 20, the dielectric layer 21 and the metal layer 21 b are penetrated through 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 a 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 through holes 200, so that the conductive via 23 is electrically connected to the electrical contact of the first circuit layer 20b. The pad 201 and the second circuit layer 22. Thereafter, exposed portions are formed on the dielectric layer 21 and the second circuit layer 22 and in the conductive vias 23. The solder resist layer 24 (such as ink or green paint) of the second circuit layer 22, but the solder resist layer 24 is not formed in the through hole 210.

Therefore, the conventional flexible and rigid combined package substrate 2 is designed to perform a flexing action by the design of the bending section A and the perforation 210.

However, in the conventional flexible and rigid combined packaging substrate 2, the flexible substrate 20 has a large variation in the interlayer dimensions, and in the lamination process, the dielectric layers 21 of different materials need to be combined at high temperature and 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 +/- 100um), so the area of the electrical contact pad 201 of the flexible board 20 needs to be increased to avoid The displacement of the hole prevents the conductive through hole 23 from being connected to the electrical contact pad 201, but also reduces the wiring area of other functional circuits of the first circuit layer 20b, resulting in the need to increase the width or decrease of the flexible board 20. The function of the flexible 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 problem of short circuit caused by the misalignment of the hole position. However, it cannot meet the requirements of fine pitch.

Furthermore, since the soft and hard interface of the package substrate 2 has two materials such as the dielectric layer 21 of the prepreg (PP) and the cover protective film 20d, after the dielectric layer 21 is laminated, here Protrusions are prone to occur, which in turn affects the ability of subsequent assembly and fitting and bending.

In addition, 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 (a certain thickness will not be broken due to deflection), and the thickness of the dielectric layer 21 (a certain Thickness to provide the required hardness) and double-sided build-up (second circuit layer 22 on the upper and lower sides), so It is difficult to reduce the thickness h of the package substrate 2 to less than 0.25 mm, so it is difficult to meet the demand for thinning.

Figures 3A to 3E are schematic cross-sectional views of a third method of manufacturing a conventional flexible-hard-type package substrate 3;

As shown in FIG. 3A, a hard board 31 having an opening 311 is provided, which includes a hard substrate 31 a and internal circuit layers 31 c provided on opposite sides of the hard substrate 31 a. For example, the hard substrate 31a and the inner circuit layer 31c are made of a copper foil substrate (CCL), and the hard substrate 31a is penetrated by mechanical drilling to form the opening 311.

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

As shown in FIG. 3C, a dielectric layer 31d having a perforation 310 is pressed on the opposite sides of the hard plate 31 and the soft plate 30 respectively, and the perforations 310 correspond to the flexing section A to make the flexure The folded sections A are exposed from the perforations 310. Next, a metal layer 31b such as a copper material is formed on the dielectric layers 31d, the hole wall of the through hole 310, and the flexure A. Thereafter, the hard board 31, the dielectric layer 31d, and the metal layer 31b are penetrated to form a plurality of through holes 300, and the dielectric layer 31d and the metal layer 31b are penetrated to form a plurality of exposed portions of the first circuit layer 30b.孔 301。 Hole 301.

The dielectric layer 31d is a prepreg (PP), and the dielectric layer 31d combines the hard board 31 and a part of the first circuit layer 30b of the soft board 30 and a part of the protective film 30d.

As shown in FIG. 3D, the metal layer 31b is used to electroplat a conductive material 32a on the entire layer of the metal layer 31b, on the walls of the through holes 300, and in the blind holes 300, and then pattern-etch the metal. Layer 31b and the conductive material 32a, so as to form a second circuit layer 32 on the dielectric layer 31d, and to form in the through holes 300 electrically connecting the internal circuit layers 31c and the second circuit layer 32 A conductive via 33 is formed in the blind holes 301 to form conductive blind holes 320 for electrically connecting the first and second circuit layers 30b, 32. Thereafter, a layered circuit structure 35 for electrically connecting the second circuit layer 32 is formed on the dielectric layer 31d, and an exposed portion of the layered circuit structure 35 is formed on the layered circuit structure 35 for soldering. Layer 34 (such as ink or green paint).

As shown in FIG. 3E, the material corresponding to the perforation 310 (that is, the layered circuit structure 35, the conductive material 32a, and the metal layer 31b) is removed by mechanical resection, and the flexure A is exposed (that is, exposed) This cover protective film 30d).

Therefore, the conventional flexible and rigid package substrate 3 is designed to perform a flexing operation by the design of the flexure section A.

However, in the conventional soft-hard combined packaging substrate 3, because the second circuit layer 32 is manufactured by a subtractive method (that is, by etching the metal layer 31b and the conductive material 32a), it is limited by the ability of the circuit process. The line width / space (L / S) of the second circuit layer 32 can only be greater than or equal to 40 / 40um, and cannot be less than 40 / 40um.

Furthermore, since the soft-hard interface of the package substrate 3 has two materials such as a dielectric layer 31d and the cover protective film 30d, after the dielectric layer 31d is laminated, the soft board 30 easily occurs here. Issues such as edge protrusions and PP overflow glue affect the ability of subsequent assembly and fitting and bending.

In addition, since the thickness of the hard board 31 needs to match the thickness of the soft board 30 (the soft board 30 must have a certain thickness so as not to be broken due to deflection), it is difficult to reduce the thickness L of the package substrate 3 to Below 0.25mm, it is difficult to meet the demand for thinning.

FIG. 4 is a schematic cross-sectional view of a fourth manufacturing method of a conventional soft-hard combined packaging substrate 4.

As shown in FIG. 4, a circuit board 40 having a bent section A is laminated on opposite sides of a core board 9, which has a circuit layer 40 b, a soft portion 40 c, and a first dielectric layer 40 d. 40b is pressed onto the core board 9 and the first dielectric layer 40d has an opening 400 corresponding to the flexing section A, so that the soft portion 40c is exposed from the opening 400. Then, a second dielectric layer 41 with a through hole 410 and a protective film 90 are laminated according to requirements.

Therefore, the conventional soft-hard combined package substrate 4 uses the design of the opening 400, the perforation 410, and the bending section A to perform a flexing action, and the circuit layer 40b is not limited to the circuit making ability of the subtraction method.

However, in the conventional soft-hard combined packaging substrate 4, since the soft-hard interface of the packaging substrate 4 has two materials such as a soft portion 40c and a first dielectric layer 40d, the second dielectric layer is laminated. After 41, the problem that the corner edges of the opening 400 (or the perforation 410) protrude easily occurs due to uneven stress distribution, which further affects the subsequent assembly and fitting and bending capabilities.

Furthermore, the package substrate 4 needs to be provided with the core plate 9 so that the thickness can be reduced to a limited extent, which is not conducive to thinning requirements.

Therefore, how to overcome the various problems in the conventional technology has become an urgent problem to be solved.

In view of the lack of the above-mentioned conventional technology, the present invention provides a flexible substrate, including: a substrate body, which is a coreless form, has a flexure section and at least one dielectric layer, and a material system forming the dielectric layer Is a mold compound or a primer; and an additional part is formed on the substrate body and has a perforation so that the flexure section is exposed through the perforation.

The invention further provides a method for manufacturing a flexible substrate, which includes: providing a substrate body, wherein the substrate system is a coreless form and has a flexure section, and includes 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 includes an insulating layer, a conductive pillar embedded in the insulating layer, and a stopper penetrating the insulating layer; and Except for the stopper, a perforation is formed on the additional part so that the flexure section is exposed through the perforation.

In the aforementioned flexible substrate and manufacturing method, the additional component includes 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, which comprises: forming a substrate body on a carrier board, wherein the substrate is a coreless system, and has a flexure section and at least one dielectric layer, and forms the substrate. The material of the dielectric layer is a molding compound or a primer; and a part of the material of the carrier plate is removed to form a perforation penetrating the carrier plate and the carrier plate with the perforation is used as an additional part, and the flexure is exposed In the perforation.

In the aforementioned flexible substrate and manufacturing method, the additional component is a metal plate.

In the aforementioned flexible substrate and the two manufacturing methods, the substrate body further includes a circuit structure combined with the dielectric layer.

It can be known from the above that in the flexible substrate and the two manufacturing methods of the present invention, a layering material and a product structure different from the conventional technology are used to greatly increase the circuit density of the rigid-flex board structure and reduce the overall substrate thickness. 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‧‧‧Flexible board

10a, 20a, 30a‧‧‧Core layer

10b, 20b, 30b ‧‧‧ first circuit layer

10c, 20c, 30c‧‧‧ Overlay

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

100,200,300‧‧‧through holes

101,201‧‧‧electric contact pad

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 material

13,23,33‧‧‧Conductive vias

14,24,34‧‧‧Solder mask

21,31d, 550‧‧‧Dielectric layer

301‧‧‧ blind hole

31c‧‧‧Internal circuit layer

311,400‧‧‧ opening

320‧‧‧ conductive blind hole

35‧‧‧Additional line structure

40‧‧‧Circuit board

40b, 551‧‧‧line layer

40c‧‧‧Soft Department

40d‧‧‧First dielectric layer

41‧‧‧Second dielectric layer

5,6,7‧‧‧Flexible substrate

5a, 5b, 60,70‧‧‧Additions

50‧‧‧carrying plate

51‧‧‧The first conductive post

52‧‧‧Second conductive post

53‧‧‧First insulation layer

530‧‧‧first perforation

54‧‧‧Second insulation layer

540‧‧‧second perforation

55‧‧‧ substrate body

552‧‧‧conductor

56‧‧‧Surface treatment layer

59a, 59b, 69‧‧‧ stop

62‧‧‧ conductive post

64‧‧‧ Insulation

651‧‧‧Electromagnetic shielding layer

77‧‧‧Insulation protective layer

770‧‧‧opening area

771‧‧‧ opening

9‧‧‧Core board

90‧‧‧ protective film

A, F‧‧‧Folding section

H, h, L, D, d, R‧‧‧thickness

e‧‧‧distance

t‧‧‧ overflow glue

Figures 1A to 1D are schematic cross-sectional views of the first manufacturing method of the conventional soft-hard combined packaging substrate; Figures 2A to 2D are schematic cross-sectional views of the second manufacturing method of the conventional flexible-hard combined packaging substrate; 3A to 3E The figure is a schematic cross-sectional view of the third manufacturing method of the conventional soft-hard combined packaging substrate. The fourth figure is the cross-sectional schematic view of the fourth manufacturing method of the conventional soft-hard combined packaging substrate. The 5A to 5F are the drawings of the present invention. A schematic cross-sectional view of the first embodiment of the flexible substrate manufacturing method; Figures 6A to 6C are schematic cross-sectional views of the second embodiment of the flexible substrate manufacturing method of the present invention; and Figures 7A to 7B are A schematic cross-sectional view of a third embodiment of a method for manufacturing a flexible substrate according to the present invention.

The following describes the embodiment of the present invention by using specific embodiments. Formula, those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

It should be noted that the structures, proportions, sizes, etc. shown in the drawings in this specification are only used to match the content disclosed in the specification for the understanding and reading of those skilled in the art, and are not intended to limit the implementation of the present invention. The limited conditions are not technically significant. Any modification of the structure, change of the proportional relationship, or adjustment of the size should still fall within the scope of this invention without affecting the effects and goals that can be achieved by the present invention. The technical content disclosed by the invention can be covered. At the same time, the terms such as "upper", "lower", "first", "second", and "one" cited in this specification are only for the convenience of description, and are not intended to limit the present invention. The scope of implementation, the change or adjustment of its relative relationship, without substantial changes in the technical content, should also be regarded as the scope of the present invention.

5A to 5F are schematic sectional views of the first embodiment of the method for manufacturing the flexible substrate 5 according to the present invention.

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

In this embodiment, the carrier plate 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 plate 50 to cover the first conductive pillars 51 and the stoppers 59 a, and the surfaces of the first conductive pillars 51 and the stoppers 59 a are formed. The surface is flush with the first insulating layer On the surface of 53, the first conductive pillars 51 and the stopper 59 a are exposed to the first insulating layer 53, and the stopper 59 a penetrates the first insulating layer 53.

In this embodiment, the first insulating layer 53 is used as a hard part, which is formed on the carrier plate 50 by a casting method, a coating method, or a compression bonding method, and the material forming the first insulating layer 53 is used as an intermediary. The electrical material may be epoxy resin, and the epoxy resin further includes a molding compound or a primer such as an epoxy molding resin (EMC), wherein, the The epoxy molding 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 a coreless form, which can be manufactured by a circuit layer-adding process. Therefore, the substrate body 55 includes at least one dielectric layer 550 made by coating, and combined with the A circuit layer 551 of the dielectric layer 550 and a plurality of blind hole-type conductors 552 disposed in the dielectric layer 550 and electrically connected to the circuit layer 551.

Furthermore, in other embodiments, the substrate body 55 may also be manufactured by a casting process. For example, a circuit layer 551 is formed on the first insulating layer 53 first, and then a conductive pillar is formed on the circuit layer 551. The dielectric layer 550 is formed by a mold to cover the circuit layer 551 and the conductive pillar, and the conductive pillar is used as the conductive body 552, and the number of layers can be increased according to the above steps.

In addition, the dielectric layer 550 is a soft part, 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 and the first insulating layer 53 may be another type or the same type of epoxy resin.

As shown in FIG. 5D, a plurality of second conductive pillars 52 and stoppers 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 and The stoppers 59b, and the surfaces of the second conductive posts 52 and the surface of the stoppers 59b are flush with the surface of the second insulating layer 54 so that the second conductive posts 52 and the stoppers 59b are exposed outside the The second insulating layer 54, and the stopper 59 b penetrates the second insulating layer 54.

In this embodiment, the second conductive pillar 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.

In addition, the second insulating layer 54 is a hard part, which is formed by a casting method, a coating method, or a compression bonding method, and the material forming the second insulating layer 54 is a dielectric material, which may be epoxy. Resin, and the epoxy resin further includes a molding compound or a primer, such as an epoxy molding resin, wherein the epoxy molding resin contains a filler, wherein the content of the filler is 70-90 wt%.

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 and the material of the dielectric layer 550 may be the same or different.

As shown in FIGS. 5E and 5F, the carrier plate 50 is removed by peeling, 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 so that the substrate body 55 is exposed from the first and second through-holes 530 and 540 to serve as a bending section F, and the first conductive pillars 51 and the first insulating layer 53 can be regarded as an additional member 5a, and the second conductive pillars 52 and the The second insulating layer 54 can be regarded as another additional member 5b.

In this embodiment, when the stopper 59 a is removed, a part of the material of the substrate body 55 may be removed together as required, so that the first through hole 530 extends into the substrate body 55. Similarly, the second through hole 540 can also be extended into the substrate body 55 as required.

Furthermore, in subsequent processes, the additional parts 5a, 5b can form a surface treatment layer 56 on the first and second conductive pillars 51, 52 as required.

Therefore, the flexible substrate 5 of the present invention is to fabricate the substrate body 55 directly on the first insulating layer 53 (that is, to coat the dielectric layer 550) to replace the conventional laminating or laminating layers, so The soft-hard interface of the present invention is a direct combination of dielectric materials (for example, two layers of epoxy resin are directly bonded), so the disadvantages of the conventional soft-hard board in the soft-hard interface can be completely eliminated. The soft-hard interface does not have problems such as overflow, lack of glue, protrusions, etc., as in the conventional technology, and can improve the inter-layer alignment accuracy to +/- 25um (the inter-layer alignment accuracy of the conventional soft-hard bonded board is +/- 100um ).

In addition, the substrate body 55 is a coreless form, so the total thickness of the flexible substrate 5 can be greatly reduced. For example, the thickness D of the four-layer board form can be less than 0.2mm, such as 0.16mm, which is less than the conventional technology. The thickness of the four-layer board (about 0.25mm).

In addition, the substrate body 55 is fabricated by using a semi-additive method for the circuit layer 551 (that is, the circuit layer 551 is directly plated) without etching a metal material. Therefore, the edge of the circuit layer 551 is straight, and there is no etching process. The residual problem caused by it is conducive to impedance control, and the line width / space of the line layer 551 can be reduced to 20 / 20um (the line width / space of the line produced by the conventional layer reduction method is the smallest 40 / 40um).

In addition, the connection position of the present invention (that is, the flexure section F) is matched with the patterned plated thick copper (the blocks 59a, 59b) and the etching to remove the thick copper (the blocks 59a, 59b) by image transfer. The shape, size, and accuracy of the flexure section F are not limited by conventional machining, so the freedom of mechanism design can be improved (for example, multiple sets of flexure sections F of any shape can be made simultaneously), And because the stoppers 59a, 59b can be made with the first and second conductive pillars 51, 52, the processing cost can be reduced.

In addition, the outermost (that is, the outer layer of the hard board region) contact pads of the flexible substrate 5 of the present invention are made in the form of copper pillars (that is, the first and second conductive pillars 51 and 52), and are made of a dielectric material. (The first and second insulating layers 53, 54) replace the conventional solder resist layer, so the present invention can strengthen the contact pad (the first and second conductive posts 51, 52) and the dielectric material (the first and second The bonding force between the two insulating layers 53 and 54) and the bonding strength of the subsequent bonding process can be improved, thereby improving the reliability and packaging ability of the product.

6A to 6C are schematic sectional views of a second embodiment of a method for manufacturing a flexible substrate 6 according to the present invention. The difference between this embodiment and the first embodiment lies in the number of perforations, and 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 plate 50, and the dielectric layers 550 are used as soft portions, and the dielectric layer 550 is formed on the carrier plate 50 by a coating method.

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

In this embodiment, the conductive pillar 62 and the stopper 69 are metal materials, such as copper, and the materials of the two can be the same or different.

Moreover, the insulating layer 64 is a hard part, which is formed by a casting method, a coating method, or a compression bonding method, and the material forming the insulating layer 64 is a dielectric material, which may be an epoxy resin, and the The epoxy resin further includes a molding compound or a primer, such as an epoxy molding resin, wherein the epoxy molding resin contains a filler, wherein the content of the filler is 70 to 90 wt%.

In addition, the material of the dielectric layer 550 may be the same as or different from that of the insulating layer 64. For example, the dielectric layer 550 may be one of the types of epoxy, and the insulating layer 64 may be a ring. Another type or the same type of epoxy resin.

As shown in FIG. 6C, the stopper 69 is removed by etching to form a through hole 640 on the insulating layer 64, so that the substrate body 55 is exposed from the through hole 640, so that the substrate body 55 is exposed from a portion of the through hole 640. As the flexure section F. After that, the carrier plate 50 is removed, and the conductive pillars 62 and the insulating layer 64 can be regarded as an additional component 60.

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

Furthermore, when the carrier plate 50 is removed, the flexible plate portion (the substrate The main body 55) is an electroplated copper layer (part of the circuit layer 551) on the exposed side to serve as the electromagnetic shielding layer 651, and it is not necessary to additionally coat a silver adhesive conductive film as the electromagnetic shielding.

In the subsequent processes, a surface treatment layer (not shown) may be formed on the conductive pillars 62 according to requirements.

Therefore, in the flexible substrate 6 of the present invention, the substrate body 55 is directly fabricated on a single side of the carrier board 50, so that a layer of a soft plate portion (the dielectric layer 550) or a hard plate portion (the insulating layer 64) is formed. The number can be arbitrarily selected, and is not limited by the symmetrical build-up of the core layer design on both sides of the conventional technology.

Furthermore, the flexible substrate 6 of the present invention has a soft-hard junction only on one side of the substrate body 55, and the place is a direct combination of two layers of epoxy resin (the dielectric layer 550 and the insulating layer 64). Therefore, the shortcomings of the conventional soft-hard combination board in the soft-hard interface can be completely eliminated, that is, the soft-hard interface of the present invention does not have problems such as overflow, lack of glue, protrusions and the like of the conventional technology, and can reduce the flexibility. Fold variation.

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

In addition, the outermost (that is, the outer layer of the hard board region) contact pad of the flexible substrate 6 of the present invention is made 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 is known, so the present invention can strengthen the bonding force between the contact pad (the conductive pillar 62) and the dielectric material (the insulating layer 64), and improve the bonding strength of the subsequent bonding process, thereby improving the reliability of the product. And packaging capabilities.

In addition, the connection position of the present invention (that is, the flexure F) is produced by image transfer with patterned thick copper plating (the stopper 69) and etching to remove the thick copper (the stopper 69). The shape, size and accuracy of the flexure section F are not limited by conventional machining, so the freedom of mechanism design can be improved (for example, multiple sets of flexure sections F of any shape can be made at the same time). 69 can be manufactured together with the conductive pillar 62, which can reduce the processing cost.

7A to 7B are schematic sectional views of a third embodiment of a method for manufacturing a flexible substrate 7 according to the present invention. The difference between this embodiment and the second embodiment lies in the manufacturing method of the perforation. The other processes are roughly the same, so only the differences will be described below, and the same points will not be described again.

As shown in FIG. 7A, following the process of FIG. 6A, an insulating protection layer 77 is formed on the substrate body 55, which has a plurality of openings 771 exposing the circuit layer 551 and at least one exposing the dielectric layer 550. The opening area 770, and in this embodiment, the carrier plate 50 is a metal plate.

As shown in FIG. 7B, a part of the material of the carrier plate 50 is removed by etching at a position corresponding to the opening area 770, so that a hole 700 penetrating the carrier plate 50 is formed on the carrier plate 50 corresponding to the opening area 770. The substrate body 55 is exposed from the perforation 700, so that the carrier plate 50 having the perforation 700 is used as an add-on 70 (can be regarded as a hard part), and the part of the substrate body 55 exposed from the perforation 700 is used as a flexure section. F.

Therefore, the flexible substrate 7 of the present invention uses a metal plate as the carrier plate 50 to perform a layer-increasing process thereon, and reserves a part of the carrier plate 50 as the add-on 70 to serve as a support for the hard board area. And cooling use.

Furthermore, the flexible substrate 7 of the present invention has a soft-hard junction only on one side of the substrate body 55, and the place is a dielectric material (the dielectric layer 550) and a metal material (the carrier plate 50). Directly combine, and then etch and remove part of the material of the carrier plate 50 to form the perforation 700 penetrating the carrier plate 50, so that the disadvantages of the conventional soft-hard board in the soft-hard interface can be completely eliminated, which is the present The soft-hard interface of the invention is free from problems such as overflow, lack of glue, and protrusions of the conventional technology.

In addition, the connection position of the present invention (that is, the flexure section F) is made by etching metal (a part of the material of the bearing plate 50), so the shape, size and accuracy of the flexure section F are not subject to conventional mechanical processing. The limitation of the mechanism can increase the degree of freedom in the design of the mechanism. For example, multiple sets of flexure sections F of any shape can be made at the same time.

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

The present invention provides a flexible substrate 5, 6, 7, which includes: a substrate body 55 and at least one additional member 5a, 5b, 60, 70.

The substrate body 55 is a coreless form and has at least one bending section F.

The additional pieces 5a, 5b, 60, 70 are formed on the substrate body 55, and the additional pieces 5a, 5b, 60, 70 have perforations 640,700 (the first and second perforations 530,540) to make the flexible The folding section F is exposed at 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 circuit structure (eg, the circuit layer 551 and / or the conductive body 552) combined with the dielectric layer 550.

In one embodiment, the extensions 5a, 5b, and 60 include an insulating layer 64 (the first and second insulating layers 53, 54) and a conductive pillar 62 (the first and second electrodes) embedded in the insulating layer 64. 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 one embodiment, the extension member 70 is a metal plate.

In summary, the flexible substrate and the manufacturing method thereof of the present invention reduce the total thickness of the flexible substrate by using the substrate body as a coreless form, so that it can meet the demand for thinning.

In addition, the soft and hard interface is a direct combination of the dielectric material and the add-on, so that the soft and hard interface will not cause conventional problems such as overflow, lack of glue, and protrusions, and can improve the accuracy of inter-layer alignment.

In addition, the substrate body is fabricated using a semi-additive method without etching metal materials, which is beneficial to impedance control, and can reduce the line width / space, so it can meet the requirements of fine pitch / fine lines.

In addition, the flexure section is defined by etching a metal material, so the shape, size and accuracy of the flexure section are not limited by the conventional mechanical processing, so the freedom of mechanism design can be improved.

The above embodiments are used to exemplify the principle of the present invention and its effects, but not to limit the present 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 rights of the present invention should be listed in the scope of patent application described later.

Claims (13)

A flexible substrate includes: a substrate body, which is a coreless form, has a flexure section, at least one dielectric layer as a soft portion, and a circuit layer combined with the dielectric layer, and forms the dielectric layer. The material is a soft mold compound or primer; and an additional part is a hard part having a hardness relative to the soft part, which is formed on the substrate body and electrically connected to the circuit layer, and has a perforation to make the flexure The segment is exposed at the perforation. The flexible substrate according to item 1 of the patent application scope, wherein the substrate body further comprises a circuit structure combined with the dielectric layer. The flexible substrate according to item 1 of the scope of the patent application, wherein the additional component includes an insulating layer and a conductive pillar embedded in the insulating layer, and the conductive pillar is electrically connected to the circuit layer of the substrate body. The flexible substrate according to item 3 of the scope of patent application, wherein the material forming the insulating layer is a hard dielectric material. The flexible substrate according to item 4 of the scope of patent application, wherein the dielectric material is a hard mold compound or a primer. The flexible substrate according to item 1 of the scope of patent application, wherein the additional component is a metal plate. A method for manufacturing a flexible substrate includes forming a substrate body in a coreless form and having a bending section on a carrier plate of a metal plate, wherein the substrate system includes at least one dielectric layer as a soft part. And a circuit layer combined with the dielectric layer, and the material forming the dielectric layer is a soft mold compound or a primer; an add-on is formed on the substrate body, wherein the add-on includes a hard insulating layer, embedded A conductive pillar in the insulating layer and a stopper penetrating the insulating layer, and the add-on is electrically connected to the circuit layer; and removing the carrier board and the stopper, so that the add-on has a perforation for the add-on The bending section is exposed in the perforation, and the additional member is used as a hard part with a hardness relative to the soft part. According to the method for manufacturing a flexible substrate described in item 7 of the scope of patent application, the method further includes, before forming the substrate body on the carrier plate, forming another add-on on the carrier plate, so that the substrate body is disposed on the carrier plate. On another add-on, the additional add-on includes another hard insulating layer, another conductive pillar embedded in the other insulating layer, and another stopper penetrating the insulating layer, and the another The add-on is electrically connected to the circuit layer of the substrate body, and when the carrier board and the stopper are removed, the other stopper is removed, so that another add-on is formed with another perforation for the The tortuous section is exposed in the other perforation, and the other add-on is used as the other hard part whose hardness is relative to the soft part. The method for manufacturing a flexible substrate according to item 7 or 8 of the scope of the patent application, wherein the substrate body further includes a circuit structure combined with the dielectric layer. According to the method for manufacturing a flexible substrate as described in item 7 or 8 of the scope of patent application, wherein the material forming the insulating layer is a hard dielectric material. According to the method for manufacturing a flexible substrate as described in item 10 of the scope of patent application, wherein the dielectric material is a hard mold compound or a primer. A method for manufacturing a flexible substrate includes forming a substrate body on a carrier plate of a metal plate, wherein the substrate has a coreless system and has a flexure section, at least one dielectric layer as a soft part, and Combine the circuit layer of the dielectric layer, and the material forming the dielectric layer is a soft mold compound or primer; and remove a part of the material of the carrier plate to form a perforation through the carrier plate so that the perforation is provided. The carrier board is used as an add-on, and the flexure is exposed to the perforation. The add-on is arranged on a single side of the substrate body as a hard part with a hardness relative to the soft part, and is electrically connected to the circuit layer. According to the method for manufacturing a flexible substrate according to item 12 of the scope of the patent application, wherein the substrate body further includes a circuit structure combined with the dielectric layer.