WO2016107061A1

WO2016107061A1 - Coreless board fabrication component and coreless board production method

Info

Publication number: WO2016107061A1
Application number: PCT/CN2015/080299
Authority: WO
Inventors: 李志东; 谢添华; 张志强
Original assignee: 广州兴森快捷电路科技有限公司
Priority date: 2014-12-31
Filing date: 2015-05-29
Publication date: 2016-07-07
Also published as: CN104540326A

Abstract

A coreless board fabrication component comprising: a support carrier and a coreless board provided on either side of the support carrier. The support carrier comprises: a carrier copper film and an outer-layer copper film provided on either side of the carrier copper film. Employment of the solution of the present application, with ingenious arrangement of the support carrier, allows the problem of coreless board warping to be solved effectively, thus increasing the yield in the production of the coreless board.

Description

Coreless board manufacturing member and coreless board manufacturing method

Technical field

The present invention relates to the field of coreless board technology, and in particular to a coreless board manufacturing member and a coreless board manufacturing method.

Background technique

With the development of high-performance, thin-film and low-cost semiconductor packaging products, the coreless thin-substrate technology has been developed. Since the coreless board is too thin, it will encounter more serious warpage problems, and it is easy to cause board damage during the manufacturing process. The problem of card scrapping.

Summary of the invention

Based on this, it is necessary to provide a coreless board manufacturing member for the warpage problem. In addition, it is also necessary to provide a method of making a coreless board.

A coreless plate manufacturing member comprising: a support carrier, and a coreless plate disposed on both sides of the support carrier; the support carrier comprising: a carrier copper foil, and an outer layer disposed on both sides of the carrier copper foil Copper foil.

In one embodiment, the surface of the carrier copper foil is roughened.

In one embodiment, the coreless plate comprises: an inner prepreg, an outer prepreg, an inner copper foil and an outer copper foil; the inner prepreg is disposed on both sides of the inner copper foil, at the outermost The outer prepreg is disposed on an outer side of the inner layer copper foil of the layer, and the outer layer copper foil is disposed on an outer side of the outer prepreg; a gap is formed in a frame of the inner layer copper foil.

In one embodiment, the inner layer of the inner copper foil is provided with a round pad which is laid around the frame of the inner layer copper foil.

In one embodiment, the outer copper foil has a gap formed by a frame.

In one embodiment, the inner layer copper foil has a frame opening gap and the outer layer The gap between the borders of the copper foil is on the same longitudinal plane.

In one embodiment, the thickness of the bezel of the inner layer copper foil and the outer layer copper foil is greater than the thickness of the middle portion.

A coreless board manufacturing method comprising: providing a support carrier; the support carrier comprises: a carrier copper foil, and an outer layer copper foil disposed on both sides of the carrier copper foil; and laminating an inner layer on the support carrier a copper foil, an inner prepreg is disposed between each inner copper foil layer, an outer prepreg is disposed outside the inner copper foil, and then an outer copper foil is disposed outside the outer prepreg and a coreless plate is formed, the inner layer A gap is formed in the frame of the copper foil; the coreless plate is separated from the support carrier.

In one embodiment, the separating the coreless plate from the support carrier further comprises: forming a gap between the frame of the inner layer copper foil; and reducing the copper of the carrier copper foil.

In one embodiment, a gap is formed between the outer copper foil and the inner copper foil.

By adopting the solution of the present application, the support carrier is ingeniously set, which can effectively overcome the problem of warpage of the coreless plate and improve the yield of the coreless plate.

DRAWINGS

1 is a schematic structural view of a coreless plate manufacturing member according to the present invention;

2 is a schematic structural view of a support carrier in an embodiment;

Figure 3 is a structural diagram of the coreless plate of Figure 1;

Figure 4 is a schematic view showing the pattern of the outer layer copper foil of Figure 1;

Figure 5 is a schematic view showing the pattern of the inner layer copper foil of Figure 1;

Figure 6 is a schematic view showing the structure of the glass fiber of Figure 1;

Figure 7 is a schematic view showing the structure of a double-layer glass fiber in an embodiment;

Figure 8 is a flow chart of a manufacturing method proposed by the present invention;

Figure 9 is a flow chart of a manufacturing method in an embodiment;

Figure 10 is a flow chart of a manufacturing method in another embodiment;

Figure 11 is a schematic view of the positioning hole design.

detailed description

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Numerous specific details are set forth in the description below in order to provide a thorough understanding of the invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention, and thus the invention is not limited by the specific embodiments disclosed below.

The coreless board manufacturing member of this embodiment includes a support carrier, and a coreless plate disposed on both sides of the support carrier. specifically:

The support carrier is an insulator, and the insulator may be a material such as BT resin, epoxy resin, ABF, polytetrafluoroethylene, hydrocarbon ceramics or the like. Since the coreless plate is thin and the plate loss or warpage is likely to occur, the support carrier of the present embodiment can be provided to support the coreless plate.

In one embodiment, the support carrier comprises: an insulating sheet, a carrier copper foil disposed on both sides of the insulating sheet, and the carrier copper foil is thick and has a thickness of 12-15 μm, which can better provide force for the manufacture of the coreless board. stand by. In addition, the both sides of the carrier copper foil are roughened to increase the bonding force after pressing.

In other embodiments, an outer layer copper foil is disposed on the outer side of the carrier copper foil, and the entire support carrier may be bonded together by pre-compression, and the opposite side of the carrier copper foil and the outer layer copper foil is roughened, that is, the surface Roughening can increase the bonding force after pressing, and it is more convenient to separate the carrier copper foil from the outer copper foil.

The structure of the outer copper foil can be applied in the coreless plate, that is, the structure of the outer copper foil is advanced It is disposed on the insulating sheet as a constituent structure of the coreless plate, and the outer copper foil and the carrier copper foil can be separated by a separation process.

In other embodiments, the support carrier can be replaced with ice. In the process of manufacturing a coreless board, firstly, it is made in an operating space below 0°, and then the coreless board is pressed in turn on both sides of the ice. After the pressing is completed, the temperature of the operating space is increased, and the ice is automatically melted. The two coreless plates can be automatically separated. The ice is made of pure water, and the ice does not leave marks after melting, and does not affect the coreless board.

Coreless board, including: inner prepreg, outer prepreg, inner copper foil and outer copper foil. Specifically, an inner layer copper foil is disposed on both sides of the inner prepreg, and a plurality of layers may be disposed according to design requirements, that is, a plurality of inner layer copper foils are disposed, and a plurality of inner prepregs are also disposed between the plurality of inner layer copper foils. The laminate is pressed together. Finally, an outer prepreg is further disposed on the outermost inner copper foil, and then an outer copper foil is disposed outside the outer prepreg. The thickness of the inner layer copper foil and the outer layer copper foil may be the same, and is also 2 to 5 μm.

Further, the inner layer copper foil is provided with a gap, and the gap is disposed around the edge of the inner layer copper foil, and the direction in which the gap is opened can be perpendicular to the border of the inner layer copper foil, or can be set at an angle, and the gap design can be effective. Reduce the problem of voiding in the laminate. In addition, a round pad may be provided inside the inner layer copper foil, and the round pad is uniformly disposed inside the frame of the inner layer copper foil and arranged in a ring shape. The use of a round pad design can more effectively reduce the voids in the laminate fill. In the present embodiment, the gap is 0.5 to 1.5 mm, and the gap of the round pad is between 0.2 and 0.5 mm.

In other embodiments, the inner surface of the outer copper foil may also be patterned to form small bumps that effectively squeeze the air bubbles in the fill during the lamination process.

The outer copper foil is placed on the outermost side and has two outer copper foils. Specifically, the outer copper foil is provided with a gap, and the gap is disposed around the inner layer copper foil, and the gap can be opened in a direction perpendicular to the outer copper foil frame, or can be disposed at an angle, and the gap design can be effective. Reduce the problem of voiding in the laminate. In addition, the gaps formed by the inner layer copper foil and the outer layer copper foil are all disposed on the same longitudinal plane, which can better reduce the problem of no void in the laminated glue.

In other embodiments, the thickness of the frame of the inner layer copper foil and the outer layer copper foil is thicker than the thickness of the middle portion, which can effectively increase the strength of the coreless plate.

In one embodiment, the inner prepreg and the outer prepreg of the coreless manufacturing member both contain glass fibers.

Since the structures on both sides of the support carrier are the same, in order to more clearly describe the structure of the present scheme, the structure on one side will be described.

Specifically, the main component of the inner-cured sheet and the outer-cured sheet is a resin, and the glass fiber layer is contained in the resin. The thickness of the glass fiber layer of the inner curing sheet is 10 to 25 μm, and the rubber content of the resin is more than 75%; the thickness of the glass fiber of the outer curing sheet is at least 8 μm larger than the thickness of the glass fiber of the inner curing sheet, and the resin content of the outer curing sheet is less than that of the resin. 65%. Through the differentiated resin content, the stress distribution in the plate can be effectively controlled, and the warpage can be reduced.

Embodiment 1

Embodiment 2

Embodiment 3

The warpage height refers to the height difference between the two ends of the coreless board; the warpage is the height difference divided by the length of the board to represent the degree of warpage of the board.

The above examples all show that the difference in glass fiber thickness between the outer curing sheet and the inner curing sheet is controlled to be greater than 8 μm, and the warpage curvature can be effectively controlled to be less than 1%, and the warpage height difference is not higher than 5 mm. And the greater the difference in glass fiber thickness, the lower the warpage.

By asymmetrically adjusting and matching the glass fiber thickness of the different layers of the prepreg and the resin content, the coreless plate warpage can be reduced simply and at low cost.

In addition, a double-layered glass structure can also be provided in the outer curing sheet. The double-layer fiberglass structure comprises a first glass fiber layer and a second glass fiber layer, wherein the first glass fiber layer is on the outer side, the second glass fiber layer is on the inner side, and the first glass fiber layer is thicker than the second glass fiber layer. And the thickness difference is greater than 8 μm.

The difference in thickness of the glass fiber can be adjusted according to the number and distribution density of the laser blind holes. The more the number of holes, the larger the distribution density, and the greater the difference in thickness. Double-layer glass fiber is more effective than single-layer glass fiber, which can effectively reduce the warpage of coreless board.

Based on the above-mentioned coreless board and coreless board manufacturing member, a coreless board manufacturing method is also proposed, including:

S100: providing a support carrier, the support carrier comprises: an insulating sheet, a carrier copper foil disposed on two sides of the insulating sheet, wherein the carrier copper foil comprises a carrier copper foil and an outer layer copper foil combined, and an outer layer copper foil thickness ratio carrier The thickness of the copper foil is small. The addition of the support carrier can increase the supply of the force-receiving body when the coreless board is produced, and can better support the manufacture of the coreless board.

S200: laminating a copper foil on a support carrier, and providing an inner prepreg between the copper foil layers to form a coreless plate.

S300: Separating the coreless plate from the support carrier.

By adopting the method, two coreless plates can be produced at one time, which is doubled compared with the conventional production efficiency, and a thick support body is prepared for the thinner coreless plate, thereby alleviating the problem of warpage of the coreless plate.

In the above step S200, the coreless plate comprises an inner prepreg, an outer prepreg, an inner layer copper foil and an outer layer copper foil. Specifically, an outer curing sheet is first attached to the copper layer supporting both sides of the carrier, and then the inner layer copper foil is attached, and the number of the inner copper foil layers to be added is controlled according to the required number of layers, and the two inner layers are connected. At least one inner solidified sheet is sandwiched between the layers of copper foil.

Taking a five-layer coreless board as an example, the support carrier is provided with an outer layer of copper foil on both sides, and an outer prepreg is applied on the outer copper foil for one press-fitting; and then three inner layers of copper foil are sequentially added, in each of the two layers. There is an inner prepreg between the layers of copper foil, and each time a layer of inner copper foil is added, a press-fit is performed. Finally, an outer solidified sheet is laid on the inner layer of the third layer of copper foil, and an outer layer of copper foil is placed on the outer solidified sheet, and then the final pressing is performed. After pressing, the support carrier is peeled off by a separation process to obtain two five-layer boards having the same structure.

An inner layer copper foil is disposed on both sides of the inner prepreg, and a plurality of layers may be disposed according to design requirements, that is, a plurality of inner layer copper foils are disposed, and at the same time, a plurality of inner prepregs are disposed between the plurality of inner layer copper foils, and the laminated layers may be laminated. put them together. Finally, an outer prepreg is further disposed on the outermost inner copper foil, and then an outer copper foil is disposed on the outer prepreg.

In one embodiment, the inner copper foil is not bonded to the outer copper foil.

Specifically, the maximum temperature of the press-bonded inner layer copper foil and the inner solidified sheet is 140-180 ° C, the pressing time is 60 min-100 min, and the highest pressure value is 30-50 kgf/cm ² ; The outermost copper foil has a maximum temperature of 220 to 260 ° C, a pressing time of more than 110 min, and a maximum pressure of 30 to 50 kgf/cm ² . The following are the specific experimental data pressed according to this scheme:

Embodiment 4

Example 5

Example 6

During the pressing process, the inner prepreg and the inner layer copper foil are pre-compressed, and the outer layer is fully pressed, and the pressing temperature and the pressing time are both increased. Compared with the conventional press-fit, the internal prepreg after pressing with the compression parameters in this scheme only accounts for 70-95% of the conventional parameters, and is pressed by the full press-fit parameter in the final outer layer press-bonding process. In combination, the residual stress of the entire inner layer prepreg is reduced, and the warpage of the coreless plate is reduced.

In one embodiment, the inner layer copper foil is provided with a gap, and the gap is disposed around the inner layer copper foil, and the gap can be opened in a direction perpendicular to the inner layer of the copper foil, or can be angled. This gap design can effectively reduce the problem of voiding in the laminated glue. In addition, a round pad may be provided inside the inner layer copper foil, and the round pad is uniformly disposed inside the frame of the inner layer copper foil and arranged in a ring shape. The use of a round pad design can more effectively reduce the voids in the laminate fill. In the present embodiment, the gap is 0.5 to 1.5 mm, and the gap of the round pad is between 0.2 and 0.5 mm.

In other embodiments, the inner surface of the outer layer copper foil may also be patterned, which is a small protrusion, which effectively squeezes the bubbles in the glue during the lamination process.

The outer copper foil is placed on the outermost side and has two outer copper foils. Specifically, the outer copper foil is provided with a gap, and the gap is disposed around the inner layer copper foil, and the gap can be opened in a direction perpendicular to the outer copper foil frame, or can be disposed at an angle, and the gap design can be effectively reduced. There is no hole in the lamination.

In addition, the thickness of the frame of the inner layer copper foil and the outer layer copper foil can be set thicker, and the strength of the coreless board can be effectively increased.

In an embodiment, in the support carrier provided in step S100, the support carrier is directly formed by superposing a carrier copper foil and an outer layer copper foil, and the structure of the outer copper foil can be applied to the coreless board, that is, in advance The structure of the outer copper foil is disposed on the insulating sheet as a constituent structure of the coreless plate; the carrier copper foil can also be applied to the coreless plate on the other side as the outermost outer copper foil.

In this embodiment, after step S300, step S400 is further included: copper reduction is performed on the carrier copper foil. Specifically, when the support carrier is separated, the support carrier is located in one of the two coreless plates, and the coreless plate with the support carrier needs to be reduced in copper, generally 2 to 5 mm, which is two coreless plates. The thickness is consistent.

By adopting the solution, the insulating sheet in the supporting carrier is omitted, the extra material waste is avoided, and the economic benefit is improved.

In addition, when separating the two coreless plates, it is impossible to confirm which piece of the coreless plate the support carrier is. Therefore, manual visual confirmation is required, which greatly reduces work efficiency. Therefore, it is also necessary to add step S300A before step S400: providing a laser range finder, respectively measuring the thickness of the two coreless plates, the thicker is a coreless plate having a supporting carrier, and then entering the coreless plate into step S400 .

Specifically, the laser range finder includes a laser emitting end and a laser receiving end, and the laser emitting end and the laser receiving end are respectively disposed at two ends of the coreless board, and emit laser light from the laser emitting end from a preset height, and the laser receiving end The end receives the laser. When the laser receiving end does not receive the laser signal, this time is the thickness of the coreless board. Similarly, another coreless panel uses the same method for its thickness detection. Finally, by comparison, it can be confirmed which coreless board is a thicker coreless board, and is a coreless board having a supporting carrier.

In an embodiment, step S200 specifically includes:

S200A: Pattern transfer is performed on the outer copper foil on both sides of the support carrier, wherein the pattern on one side is a pattern after the other side is rotated by 180 degrees.

S200C: The inner prepreg and the inner layer copper foil are added on both outer sides of the support carrier, and the pattern is transferred on the inner layer copper foil on both sides, and the pattern on the support side is the pattern on the other side rotated by 180 degrees, and is pressed. .

S200D: Step S200B is repeated until the set number of layers is reached.

The coreless board is used to carry the semiconductor elemental gas, so the corresponding circuit trace is required on the coreless board. The circuit layer of the coreless board is an inner layer copper foil and an outer layer copper foil of each layer, and each layer of copper foil is electrically connected by a drilling process. Since the upper and lower coreless structures are in a flip-chip relationship, the circuit layout on the two coreless structures peeled off from the support carrier is a mirror image relationship, and the circuit layout of the two coreless boards is different in any case. It is produced in two sets of processes, and the production efficiency is slow. By inverting the image referenced by the production circuit in advance, only one of the coreless plates needs to be flipped in the following, and the two coreless plates obtain the same pattern, and the subsequent processing can be performed simultaneously.

Further, after step S200A, the method further includes:

S200B, a positioning hole is formed on the board. Correspondingly, step S200C is specifically: adding an inner prepreg and an inner layer copper foil on both outer sides of the support carrier, and performing pattern transfer on the inner layer copper foil on both sides, and the pattern on the support carrier side is rotated 180 degrees on the other side. The graphic is transferred with the positioning hole as the alignment reference and pressed.

The positioning hole can be used to facilitate the pattern alignment during the pattern transfer, and can be used for marking after separating the coreless board, so that the pattern direction of the board can be discriminated by the distribution of the positioning holes. The inner copper foil needs to be milled before starting the positioning hole. The size of the milling edge is less than 2-6 mm, and the outer copper foil size is 5-15 mm larger than the inner copper foil.

The positioning holes are asymmetrically distributed. In addition, the positioning hole may also be a positioning reference such as a specific positioning mark, mainly serving as a reference, and is not limited to the form of the positioning hole.

The above-mentioned embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A coreless plate manufacturing member, comprising: a support carrier; and a coreless plate disposed on both sides of the support carrier;

The support carrier includes: a carrier copper foil, and an outer layer copper foil disposed on both sides of the carrier copper foil.
The coreless plate manufacturing member according to claim 1, wherein the surface of the carrier copper foil is roughened.
The coreless plate manufacturing member according to claim 2, wherein the coreless plate comprises: an inner prepreg, an outer prepreg, an inner layer copper foil and an outer layer copper foil; and the inner layer copper foil is disposed on both sides In the inner prepreg, the outer prepreg is provided on the outer side of the outermost inner layer copper foil, and the outer layer copper foil is provided on the outer side of the outer prepreg; the inner layer copper foil has a gap formed in the frame.
The coreless board manufacturing member according to claim 3, wherein a circular pad is provided inside the inner layer copper foil, and the round pad is laid around a frame of the inner layer copper foil.
The coreless board manufacturing member according to claim 4, wherein a gap is formed in a frame of the outer layer copper foil.
The coreless plate manufacturing member according to claim 5, wherein the frame opening gap of the inner layer copper foil and the frame opening gap of the outer layer copper foil are on the same vertical plane.
The coreless board manufacturing member according to claim 6, wherein a thickness of a frame of the inner layer copper foil and the outer layer copper foil is larger than a thickness of a middle portion thereof.
A method for making a coreless board, comprising:

Providing a support carrier; the support carrier comprises: a carrier copper foil, and an outer layer copper foil disposed on both sides of the carrier copper foil;

An inner layer copper foil is laminated on the support carrier, an inner prepreg is disposed between the inner copper foil layers, an outer prepreg is disposed on the outer side of the inner copper foil, and then an outer copper foil is disposed outside the outer prepreg and Forming a coreless plate, the inner layer of the copper foil has a gap;

The coreless plate is separated from the support carrier.
The coreless board manufacturing method according to claim 8, wherein the separating the coreless board from the support carrier further comprises:

A gap is formed in the frame of the inner layer copper foil; copper is reduced on the carrier copper foil.
The coreless plate manufacturing method according to claim 9, wherein a gap is formed between the outer layer copper foil and the inner layer copper foil.